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 /arm Files generic to ARM architecture
136 /cpu CPU specific files
137 /arm720t Files specific to ARM 720 CPUs
138 /arm920t Files specific to ARM 920 CPUs
139 /at91 Files specific to Atmel AT91RM9200 CPU
140 /imx Files specific to Freescale MC9328 i.MX CPUs
141 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
142 /arm926ejs Files specific to ARM 926 CPUs
143 /arm1136 Files specific to ARM 1136 CPUs
144 /pxa Files specific to Intel XScale PXA CPUs
145 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 /lib Architecture specific library files
147 /avr32 Files generic to AVR32 architecture
148 /cpu CPU specific files
149 /lib Architecture specific library files
150 /blackfin Files generic to Analog Devices Blackfin architecture
151 /cpu CPU specific files
152 /lib Architecture specific library files
153 /m68k Files generic to m68k architecture
154 /cpu CPU specific files
155 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
156 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
157 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
158 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
159 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
160 /lib Architecture specific library files
161 /microblaze Files generic to microblaze architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /mips Files generic to MIPS architecture
165 /cpu CPU specific files
166 /mips32 Files specific to MIPS32 CPUs
167 /xburst Files specific to Ingenic XBurst CPUs
168 /lib Architecture specific library files
169 /nds32 Files generic to NDS32 architecture
170 /cpu CPU specific files
171 /n1213 Files specific to Andes Technology N1213 CPUs
172 /lib Architecture specific library files
173 /nios2 Files generic to Altera NIOS2 architecture
174 /cpu CPU specific files
175 /lib Architecture specific library files
176 /openrisc Files generic to OpenRISC architecture
177 /cpu CPU specific files
178 /lib Architecture specific library files
179 /powerpc Files generic to PowerPC architecture
180 /cpu CPU specific files
181 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
182 /mpc5xx Files specific to Freescale MPC5xx CPUs
183 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
184 /mpc8xx Files specific to Freescale MPC8xx CPUs
185 /mpc824x Files specific to Freescale MPC824x CPUs
186 /mpc8260 Files specific to Freescale MPC8260 CPUs
187 /mpc85xx Files specific to Freescale MPC85xx CPUs
188 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
189 /lib Architecture specific library files
190 /sh Files generic to SH architecture
191 /cpu CPU specific files
192 /sh2 Files specific to sh2 CPUs
193 /sh3 Files specific to sh3 CPUs
194 /sh4 Files specific to sh4 CPUs
195 /lib Architecture specific library files
196 /sparc Files generic to SPARC architecture
197 /cpu CPU specific files
198 /leon2 Files specific to Gaisler LEON2 SPARC CPU
199 /leon3 Files specific to Gaisler LEON3 SPARC CPU
200 /lib Architecture specific library files
201 /x86 Files generic to x86 architecture
202 /cpu CPU specific files
203 /lib Architecture specific library files
204 /api Machine/arch independent API for external apps
205 /board Board dependent files
206 /common Misc architecture independent functions
207 /disk Code for disk drive partition handling
208 /doc Documentation (don't expect too much)
209 /drivers Commonly used device drivers
210 /dts Contains Makefile for building internal U-Boot fdt.
211 /examples Example code for standalone applications, etc.
212 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
213 /include Header Files
214 /lib Files generic to all architectures
215 /libfdt Library files to support flattened device trees
216 /lzma Library files to support LZMA decompression
217 /lzo Library files to support LZO decompression
219 /post Power On Self Test
220 /spl Secondary Program Loader framework
221 /tools Tools to build S-Record or U-Boot images, etc.
223 Software Configuration:
224 =======================
226 Configuration is usually done using C preprocessor defines; the
227 rationale behind that is to avoid dead code whenever possible.
229 There are two classes of configuration variables:
231 * Configuration _OPTIONS_:
232 These are selectable by the user and have names beginning with
235 * Configuration _SETTINGS_:
236 These depend on the hardware etc. and should not be meddled with if
237 you don't know what you're doing; they have names beginning with
240 Later we will add a configuration tool - probably similar to or even
241 identical to what's used for the Linux kernel. Right now, we have to
242 do the configuration by hand, which means creating some symbolic
243 links and editing some configuration files. We use the TQM8xxL boards
247 Selection of Processor Architecture and Board Type:
248 ---------------------------------------------------
250 For all supported boards there are ready-to-use default
251 configurations available; just type "make <board_name>_config".
253 Example: For a TQM823L module type:
258 For the Cogent platform, you need to specify the CPU type as well;
259 e.g. "make cogent_mpc8xx_config". And also configure the cogent
260 directory according to the instructions in cogent/README.
263 Configuration Options:
264 ----------------------
266 Configuration depends on the combination of board and CPU type; all
267 such information is kept in a configuration file
268 "include/configs/<board_name>.h".
270 Example: For a TQM823L module, all configuration settings are in
271 "include/configs/TQM823L.h".
274 Many of the options are named exactly as the corresponding Linux
275 kernel configuration options. The intention is to make it easier to
276 build a config tool - later.
279 The following options need to be configured:
281 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
283 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
285 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
286 Define exactly one, e.g. CONFIG_ATSTK1002
288 - CPU Module Type: (if CONFIG_COGENT is defined)
289 Define exactly one of
291 --- FIXME --- not tested yet:
292 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
293 CONFIG_CMA287_23, CONFIG_CMA287_50
295 - Motherboard Type: (if CONFIG_COGENT is defined)
296 Define exactly one of
297 CONFIG_CMA101, CONFIG_CMA102
299 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
300 Define one or more of
303 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
304 Define one or more of
305 CONFIG_LCD_HEARTBEAT - update a character position on
306 the LCD display every second with
309 - Board flavour: (if CONFIG_MPC8260ADS is defined)
312 CONFIG_SYS_8260ADS - original MPC8260ADS
313 CONFIG_SYS_8266ADS - MPC8266ADS
314 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
315 CONFIG_SYS_8272ADS - MPC8272ADS
317 - Marvell Family Member
318 CONFIG_SYS_MVFS - define it if you want to enable
319 multiple fs option at one time
320 for marvell soc family
322 - MPC824X Family Member (if CONFIG_MPC824X is defined)
323 Define exactly one of
324 CONFIG_MPC8240, CONFIG_MPC8245
326 - 8xx CPU Options: (if using an MPC8xx CPU)
327 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
328 get_gclk_freq() cannot work
329 e.g. if there is no 32KHz
330 reference PIT/RTC clock
331 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
334 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
335 CONFIG_SYS_8xx_CPUCLK_MIN
336 CONFIG_SYS_8xx_CPUCLK_MAX
337 CONFIG_8xx_CPUCLK_DEFAULT
338 See doc/README.MPC866
340 CONFIG_SYS_MEASURE_CPUCLK
342 Define this to measure the actual CPU clock instead
343 of relying on the correctness of the configured
344 values. Mostly useful for board bringup to make sure
345 the PLL is locked at the intended frequency. Note
346 that this requires a (stable) reference clock (32 kHz
347 RTC clock or CONFIG_SYS_8XX_XIN)
349 CONFIG_SYS_DELAYED_ICACHE
351 Define this option if you want to enable the
352 ICache only when Code runs from RAM.
357 Specifies that the core is a 64-bit PowerPC implementation (implements
358 the "64" category of the Power ISA). This is necessary for ePAPR
359 compliance, among other possible reasons.
361 CONFIG_SYS_FSL_TBCLK_DIV
363 Defines the core time base clock divider ratio compared to the
364 system clock. On most PQ3 devices this is 8, on newer QorIQ
365 devices it can be 16 or 32. The ratio varies from SoC to Soc.
367 CONFIG_SYS_FSL_PCIE_COMPAT
369 Defines the string to utilize when trying to match PCIe device
370 tree nodes for the given platform.
372 CONFIG_SYS_PPC_E500_DEBUG_TLB
374 Enables a temporary TLB entry to be used during boot to work
375 around limitations in e500v1 and e500v2 external debugger
376 support. This reduces the portions of the boot code where
377 breakpoints and single stepping do not work. The value of this
378 symbol should be set to the TLB1 entry to be used for this
381 CONFIG_SYS_FSL_ERRATUM_A004510
383 Enables a workaround for erratum A004510. If set,
384 then CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV and
385 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY must be set.
387 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV
388 CONFIG_SYS_FSL_ERRATUM_A004510_SVR_REV2 (optional)
390 Defines one or two SoC revisions (low 8 bits of SVR)
391 for which the A004510 workaround should be applied.
393 The rest of SVR is either not relevant to the decision
394 of whether the erratum is present (e.g. p2040 versus
395 p2041) or is implied by the build target, which controls
396 whether CONFIG_SYS_FSL_ERRATUM_A004510 is set.
398 See Freescale App Note 4493 for more information about
401 CONFIG_A003399_NOR_WORKAROUND
402 Enables a workaround for IFC erratum A003399. It is only
403 requred during NOR boot.
405 CONFIG_SYS_FSL_CORENET_SNOOPVEC_COREONLY
407 This is the value to write into CCSR offset 0x18600
408 according to the A004510 workaround.
410 CONFIG_SYS_FSL_DSP_DDR_ADDR
411 This value denotes start offset of DDR memory which is
412 connected exclusively to the DSP cores.
414 CONFIG_SYS_FSL_DSP_M2_RAM_ADDR
415 This value denotes start offset of M2 memory
416 which is directly connected to the DSP core.
418 CONFIG_SYS_FSL_DSP_M3_RAM_ADDR
419 This value denotes start offset of M3 memory which is directly
420 connected to the DSP core.
422 CONFIG_SYS_FSL_DSP_CCSRBAR_DEFAULT
423 This value denotes start offset of DSP CCSR space.
425 CONFIG_SYS_FSL_SINGLE_SOURCE_CLK
426 Single Source Clock is clocking mode present in some of FSL SoC's.
427 In this mode, a single differential clock is used to supply
428 clocks to the sysclock, ddrclock and usbclock.
430 - Generic CPU options:
431 CONFIG_SYS_BIG_ENDIAN, CONFIG_SYS_LITTLE_ENDIAN
433 Defines the endianess of the CPU. Implementation of those
434 values is arch specific.
437 Freescale DDR driver in use. This type of DDR controller is
438 found in mpc83xx, mpc85xx, mpc86xx as well as some ARM core
441 CONFIG_SYS_FSL_DDR_ADDR
442 Freescale DDR memory-mapped register base.
444 CONFIG_SYS_FSL_DDR_EMU
445 Specify emulator support for DDR. Some DDR features such as
446 deskew training are not available.
448 CONFIG_SYS_FSL_DDRC_GEN1
449 Freescale DDR1 controller.
451 CONFIG_SYS_FSL_DDRC_GEN2
452 Freescale DDR2 controller.
454 CONFIG_SYS_FSL_DDRC_GEN3
455 Freescale DDR3 controller.
457 CONFIG_SYS_FSL_DDRC_ARM_GEN3
458 Freescale DDR3 controller for ARM-based SoCs.
461 Board config to use DDR1. It can be enabled for SoCs with
462 Freescale DDR1 or DDR2 controllers, depending on the board
466 Board config to use DDR2. It can be eanbeld for SoCs with
467 Freescale DDR2 or DDR3 controllers, depending on the board
471 Board config to use DDR3. It can be enabled for SoCs with
472 Freescale DDR3 controllers.
474 CONFIG_SYS_FSL_IFC_BE
475 Defines the IFC controller register space as Big Endian
477 CONFIG_SYS_FSL_IFC_LE
478 Defines the IFC controller register space as Little Endian
480 CONFIG_SYS_FSL_PBL_PBI
481 It enables addition of RCW (Power on reset configuration) in built image.
482 Please refer doc/README.pblimage for more details
484 CONFIG_SYS_FSL_PBL_RCW
485 It adds PBI(pre-boot instructions) commands in u-boot build image.
486 PBI commands can be used to configure SoC before it starts the execution.
487 Please refer doc/README.pblimage for more details
489 CONFIG_SYS_FSL_DDR_BE
490 Defines the DDR controller register space as Big Endian
492 CONFIG_SYS_FSL_DDR_LE
493 Defines the DDR controller register space as Little Endian
495 CONFIG_SYS_FSL_DDR_SDRAM_BASE_PHY
496 Physical address from the view of DDR controllers. It is the
497 same as CONFIG_SYS_DDR_SDRAM_BASE for all Power SoCs. But
498 it could be different for ARM SoCs.
500 CONFIG_SYS_FSL_DDR_INTLV_256B
501 DDR controller interleaving on 256-byte. This is a special
502 interleaving mode, handled by Dickens for Freescale layerscape
505 - Intel Monahans options:
506 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
508 Defines the Monahans run mode to oscillator
509 ratio. Valid values are 8, 16, 24, 31. The core
510 frequency is this value multiplied by 13 MHz.
512 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
514 Defines the Monahans turbo mode to oscillator
515 ratio. Valid values are 1 (default if undefined) and
516 2. The core frequency as calculated above is multiplied
520 CONFIG_SYS_INIT_SP_OFFSET
522 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
523 pointer. This is needed for the temporary stack before
526 CONFIG_SYS_MIPS_CACHE_MODE
528 Cache operation mode for the MIPS CPU.
529 See also arch/mips/include/asm/mipsregs.h.
531 CONF_CM_CACHABLE_NO_WA
534 CONF_CM_CACHABLE_NONCOHERENT
538 CONF_CM_CACHABLE_ACCELERATED
540 CONFIG_SYS_XWAY_EBU_BOOTCFG
542 Special option for Lantiq XWAY SoCs for booting from NOR flash.
543 See also arch/mips/cpu/mips32/start.S.
545 CONFIG_XWAY_SWAP_BYTES
547 Enable compilation of tools/xway-swap-bytes needed for Lantiq
548 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
549 be swapped if a flash programmer is used.
552 CONFIG_SYS_EXCEPTION_VECTORS_HIGH
554 Select high exception vectors of the ARM core, e.g., do not
555 clear the V bit of the c1 register of CP15.
557 CONFIG_SYS_THUMB_BUILD
559 Use this flag to build U-Boot using the Thumb instruction
560 set for ARM architectures. Thumb instruction set provides
561 better code density. For ARM architectures that support
562 Thumb2 this flag will result in Thumb2 code generated by
565 CONFIG_ARM_ERRATA_716044
566 CONFIG_ARM_ERRATA_742230
567 CONFIG_ARM_ERRATA_743622
568 CONFIG_ARM_ERRATA_751472
569 CONFIG_ARM_ERRATA_794072
570 CONFIG_ARM_ERRATA_761320
572 If set, the workarounds for these ARM errata are applied early
573 during U-Boot startup. Note that these options force the
574 workarounds to be applied; no CPU-type/version detection
575 exists, unlike the similar options in the Linux kernel. Do not
576 set these options unless they apply!
581 The frequency of the timer returned by get_timer().
582 get_timer() must operate in milliseconds and this CONFIG
583 option must be set to 1000.
585 - Linux Kernel Interface:
588 U-Boot stores all clock information in Hz
589 internally. For binary compatibility with older Linux
590 kernels (which expect the clocks passed in the
591 bd_info data to be in MHz) the environment variable
592 "clocks_in_mhz" can be defined so that U-Boot
593 converts clock data to MHZ before passing it to the
595 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
596 "clocks_in_mhz=1" is automatically included in the
599 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
601 When transferring memsize parameter to linux, some versions
602 expect it to be in bytes, others in MB.
603 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
607 New kernel versions are expecting firmware settings to be
608 passed using flattened device trees (based on open firmware
612 * New libfdt-based support
613 * Adds the "fdt" command
614 * The bootm command automatically updates the fdt
616 OF_CPU - The proper name of the cpus node (only required for
617 MPC512X and MPC5xxx based boards).
618 OF_SOC - The proper name of the soc node (only required for
619 MPC512X and MPC5xxx based boards).
620 OF_TBCLK - The timebase frequency.
621 OF_STDOUT_PATH - The path to the console device
623 boards with QUICC Engines require OF_QE to set UCC MAC
626 CONFIG_OF_BOARD_SETUP
628 Board code has addition modification that it wants to make
629 to the flat device tree before handing it off to the kernel
633 This define fills in the correct boot CPU in the boot
634 param header, the default value is zero if undefined.
638 U-Boot can detect if an IDE device is present or not.
639 If not, and this new config option is activated, U-Boot
640 removes the ATA node from the DTS before booting Linux,
641 so the Linux IDE driver does not probe the device and
642 crash. This is needed for buggy hardware (uc101) where
643 no pull down resistor is connected to the signal IDE5V_DD7.
645 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
647 This setting is mandatory for all boards that have only one
648 machine type and must be used to specify the machine type
649 number as it appears in the ARM machine registry
650 (see http://www.arm.linux.org.uk/developer/machines/).
651 Only boards that have multiple machine types supported
652 in a single configuration file and the machine type is
653 runtime discoverable, do not have to use this setting.
655 - vxWorks boot parameters:
657 bootvx constructs a valid bootline using the following
658 environments variables: bootfile, ipaddr, serverip, hostname.
659 It loads the vxWorks image pointed bootfile.
661 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
662 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
663 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
664 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
666 CONFIG_SYS_VXWORKS_ADD_PARAMS
668 Add it at the end of the bootline. E.g "u=username pw=secret"
670 Note: If a "bootargs" environment is defined, it will overwride
671 the defaults discussed just above.
673 - Cache Configuration:
674 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
675 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
676 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
678 - Cache Configuration for ARM:
679 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
681 CONFIG_SYS_PL310_BASE - Physical base address of PL310
682 controller register space
687 Define this if you want support for Amba PrimeCell PL010 UARTs.
691 Define this if you want support for Amba PrimeCell PL011 UARTs.
695 If you have Amba PrimeCell PL011 UARTs, set this variable to
696 the clock speed of the UARTs.
700 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
701 define this to a list of base addresses for each (supported)
702 port. See e.g. include/configs/versatile.h
704 CONFIG_PL011_SERIAL_RLCR
706 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
707 have separate receive and transmit line control registers. Set
708 this variable to initialize the extra register.
710 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
712 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
713 boot loader that has already initialized the UART. Define this
714 variable to flush the UART at init time.
718 Depending on board, define exactly one serial port
719 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
720 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
721 console by defining CONFIG_8xx_CONS_NONE
723 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
724 port routines must be defined elsewhere
725 (i.e. serial_init(), serial_getc(), ...)
728 Enables console device for a color framebuffer. Needs following
729 defines (cf. smiLynxEM, i8042)
730 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
732 VIDEO_HW_RECTFILL graphic chip supports
735 VIDEO_HW_BITBLT graphic chip supports
736 bit-blit (cf. smiLynxEM)
737 VIDEO_VISIBLE_COLS visible pixel columns
739 VIDEO_VISIBLE_ROWS visible pixel rows
740 VIDEO_PIXEL_SIZE bytes per pixel
741 VIDEO_DATA_FORMAT graphic data format
742 (0-5, cf. cfb_console.c)
743 VIDEO_FB_ADRS framebuffer address
744 VIDEO_KBD_INIT_FCT keyboard int fct
745 (i.e. i8042_kbd_init())
746 VIDEO_TSTC_FCT test char fct
748 VIDEO_GETC_FCT get char fct
750 CONFIG_CONSOLE_CURSOR cursor drawing on/off
751 (requires blink timer
753 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
754 CONFIG_CONSOLE_TIME display time/date info in
756 (requires CONFIG_CMD_DATE)
757 CONFIG_VIDEO_LOGO display Linux logo in
759 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
760 linux_logo.h for logo.
761 Requires CONFIG_VIDEO_LOGO
762 CONFIG_CONSOLE_EXTRA_INFO
763 additional board info beside
766 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
767 a limited number of ANSI escape sequences (cursor control,
768 erase functions and limited graphics rendition control).
770 When CONFIG_CFB_CONSOLE is defined, video console is
771 default i/o. Serial console can be forced with
772 environment 'console=serial'.
774 When CONFIG_SILENT_CONSOLE is defined, all console
775 messages (by U-Boot and Linux!) can be silenced with
776 the "silent" environment variable. See
777 doc/README.silent for more information.
779 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
781 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
785 CONFIG_BAUDRATE - in bps
786 Select one of the baudrates listed in
787 CONFIG_SYS_BAUDRATE_TABLE, see below.
788 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
790 - Console Rx buffer length
791 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
792 the maximum receive buffer length for the SMC.
793 This option is actual only for 82xx and 8xx possible.
794 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
795 must be defined, to setup the maximum idle timeout for
798 - Pre-Console Buffer:
799 Prior to the console being initialised (i.e. serial UART
800 initialised etc) all console output is silently discarded.
801 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
802 buffer any console messages prior to the console being
803 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
804 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
805 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
806 bytes are output before the console is initialised, the
807 earlier bytes are discarded.
809 'Sane' compilers will generate smaller code if
810 CONFIG_PRE_CON_BUF_SZ is a power of 2
812 - Safe printf() functions
813 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
814 the printf() functions. These are defined in
815 include/vsprintf.h and include snprintf(), vsnprintf() and
816 so on. Code size increase is approximately 300-500 bytes.
817 If this option is not given then these functions will
818 silently discard their buffer size argument - this means
819 you are not getting any overflow checking in this case.
821 - Boot Delay: CONFIG_BOOTDELAY - in seconds
822 Delay before automatically booting the default image;
823 set to -1 to disable autoboot.
824 set to -2 to autoboot with no delay and not check for abort
825 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
827 See doc/README.autoboot for these options that
828 work with CONFIG_BOOTDELAY. None are required.
829 CONFIG_BOOT_RETRY_TIME
830 CONFIG_BOOT_RETRY_MIN
831 CONFIG_AUTOBOOT_KEYED
832 CONFIG_AUTOBOOT_PROMPT
833 CONFIG_AUTOBOOT_DELAY_STR
834 CONFIG_AUTOBOOT_STOP_STR
835 CONFIG_AUTOBOOT_DELAY_STR2
836 CONFIG_AUTOBOOT_STOP_STR2
837 CONFIG_ZERO_BOOTDELAY_CHECK
838 CONFIG_RESET_TO_RETRY
842 Only needed when CONFIG_BOOTDELAY is enabled;
843 define a command string that is automatically executed
844 when no character is read on the console interface
845 within "Boot Delay" after reset.
848 This can be used to pass arguments to the bootm
849 command. The value of CONFIG_BOOTARGS goes into the
850 environment value "bootargs".
852 CONFIG_RAMBOOT and CONFIG_NFSBOOT
853 The value of these goes into the environment as
854 "ramboot" and "nfsboot" respectively, and can be used
855 as a convenience, when switching between booting from
859 CONFIG_BOOTCOUNT_LIMIT
860 Implements a mechanism for detecting a repeating reboot
862 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
865 If no softreset save registers are found on the hardware
866 "bootcount" is stored in the environment. To prevent a
867 saveenv on all reboots, the environment variable
868 "upgrade_available" is used. If "upgrade_available" is
869 0, "bootcount" is always 0, if "upgrade_available" is
870 1 "bootcount" is incremented in the environment.
871 So the Userspace Applikation must set the "upgrade_available"
872 and "bootcount" variable to 0, if a boot was successfully.
877 When this option is #defined, the existence of the
878 environment variable "preboot" will be checked
879 immediately before starting the CONFIG_BOOTDELAY
880 countdown and/or running the auto-boot command resp.
881 entering interactive mode.
883 This feature is especially useful when "preboot" is
884 automatically generated or modified. For an example
885 see the LWMON board specific code: here "preboot" is
886 modified when the user holds down a certain
887 combination of keys on the (special) keyboard when
890 - Serial Download Echo Mode:
892 If defined to 1, all characters received during a
893 serial download (using the "loads" command) are
894 echoed back. This might be needed by some terminal
895 emulations (like "cu"), but may as well just take
896 time on others. This setting #define's the initial
897 value of the "loads_echo" environment variable.
899 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
901 Select one of the baudrates listed in
902 CONFIG_SYS_BAUDRATE_TABLE, see below.
905 Monitor commands can be included or excluded
906 from the build by using the #include files
907 <config_cmd_all.h> and #undef'ing unwanted
908 commands, or using <config_cmd_default.h>
909 and augmenting with additional #define's
912 The default command configuration includes all commands
913 except those marked below with a "*".
915 CONFIG_CMD_AES AES 128 CBC encrypt/decrypt
916 CONFIG_CMD_ASKENV * ask for env variable
917 CONFIG_CMD_BDI bdinfo
918 CONFIG_CMD_BEDBUG * Include BedBug Debugger
919 CONFIG_CMD_BMP * BMP support
920 CONFIG_CMD_BSP * Board specific commands
921 CONFIG_CMD_BOOTD bootd
922 CONFIG_CMD_CACHE * icache, dcache
923 CONFIG_CMD_CLK * clock command support
924 CONFIG_CMD_CONSOLE coninfo
925 CONFIG_CMD_CRC32 * crc32
926 CONFIG_CMD_DATE * support for RTC, date/time...
927 CONFIG_CMD_DHCP * DHCP support
928 CONFIG_CMD_DIAG * Diagnostics
929 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
930 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
931 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
932 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
933 CONFIG_CMD_DTT * Digital Therm and Thermostat
934 CONFIG_CMD_ECHO echo arguments
935 CONFIG_CMD_EDITENV edit env variable
936 CONFIG_CMD_EEPROM * EEPROM read/write support
937 CONFIG_CMD_ELF * bootelf, bootvx
938 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
939 CONFIG_CMD_ENV_FLAGS * display details about env flags
940 CONFIG_CMD_ENV_EXISTS * check existence of env variable
941 CONFIG_CMD_EXPORTENV * export the environment
942 CONFIG_CMD_EXT2 * ext2 command support
943 CONFIG_CMD_EXT4 * ext4 command support
944 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
945 that work for multiple fs types
946 CONFIG_CMD_SAVEENV saveenv
947 CONFIG_CMD_FDC * Floppy Disk Support
948 CONFIG_CMD_FAT * FAT command support
949 CONFIG_CMD_FLASH flinfo, erase, protect
950 CONFIG_CMD_FPGA FPGA device initialization support
951 CONFIG_CMD_FUSE * Device fuse support
952 CONFIG_CMD_GETTIME * Get time since boot
953 CONFIG_CMD_GO * the 'go' command (exec code)
954 CONFIG_CMD_GREPENV * search environment
955 CONFIG_CMD_HASH * calculate hash / digest
956 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
957 CONFIG_CMD_I2C * I2C serial bus support
958 CONFIG_CMD_IDE * IDE harddisk support
959 CONFIG_CMD_IMI iminfo
960 CONFIG_CMD_IMLS List all images found in NOR flash
961 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
962 CONFIG_CMD_IMMAP * IMMR dump support
963 CONFIG_CMD_IMPORTENV * import an environment
964 CONFIG_CMD_INI * import data from an ini file into the env
965 CONFIG_CMD_IRQ * irqinfo
966 CONFIG_CMD_ITEST Integer/string test of 2 values
967 CONFIG_CMD_JFFS2 * JFFS2 Support
968 CONFIG_CMD_KGDB * kgdb
969 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
970 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
972 CONFIG_CMD_LOADB loadb
973 CONFIG_CMD_LOADS loads
974 CONFIG_CMD_MD5SUM * print md5 message digest
975 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
976 CONFIG_CMD_MEMINFO * Display detailed memory information
977 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
979 CONFIG_CMD_MEMTEST * mtest
980 CONFIG_CMD_MISC Misc functions like sleep etc
981 CONFIG_CMD_MMC * MMC memory mapped support
982 CONFIG_CMD_MII * MII utility commands
983 CONFIG_CMD_MTDPARTS * MTD partition support
984 CONFIG_CMD_NAND * NAND support
985 CONFIG_CMD_NET bootp, tftpboot, rarpboot
986 CONFIG_CMD_NFS NFS support
987 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
988 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
989 CONFIG_CMD_PCI * pciinfo
990 CONFIG_CMD_PCMCIA * PCMCIA support
991 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
993 CONFIG_CMD_PORTIO * Port I/O
994 CONFIG_CMD_READ * Read raw data from partition
995 CONFIG_CMD_REGINFO * Register dump
996 CONFIG_CMD_RUN run command in env variable
997 CONFIG_CMD_SANDBOX * sb command to access sandbox features
998 CONFIG_CMD_SAVES * save S record dump
999 CONFIG_CMD_SCSI * SCSI Support
1000 CONFIG_CMD_SDRAM * print SDRAM configuration information
1001 (requires CONFIG_CMD_I2C)
1002 CONFIG_CMD_SETGETDCR Support for DCR Register access
1004 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1005 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1006 (requires CONFIG_CMD_MEMORY)
1007 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1008 CONFIG_CMD_SOURCE "source" command Support
1009 CONFIG_CMD_SPI * SPI serial bus support
1010 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1011 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1012 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1013 CONFIG_CMD_TIMER * access to the system tick timer
1014 CONFIG_CMD_USB * USB support
1015 CONFIG_CMD_CDP * Cisco Discover Protocol support
1016 CONFIG_CMD_MFSL * Microblaze FSL support
1017 CONFIG_CMD_XIMG Load part of Multi Image
1018 CONFIG_CMD_UUID * Generate random UUID or GUID string
1020 EXAMPLE: If you want all functions except of network
1021 support you can write:
1023 #include "config_cmd_all.h"
1024 #undef CONFIG_CMD_NET
1027 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1029 Note: Don't enable the "icache" and "dcache" commands
1030 (configuration option CONFIG_CMD_CACHE) unless you know
1031 what you (and your U-Boot users) are doing. Data
1032 cache cannot be enabled on systems like the 8xx or
1033 8260 (where accesses to the IMMR region must be
1034 uncached), and it cannot be disabled on all other
1035 systems where we (mis-) use the data cache to hold an
1036 initial stack and some data.
1039 XXX - this list needs to get updated!
1041 - Regular expression support:
1043 If this variable is defined, U-Boot is linked against
1044 the SLRE (Super Light Regular Expression) library,
1045 which adds regex support to some commands, as for
1046 example "env grep" and "setexpr".
1050 If this variable is defined, U-Boot will use a device tree
1051 to configure its devices, instead of relying on statically
1052 compiled #defines in the board file. This option is
1053 experimental and only available on a few boards. The device
1054 tree is available in the global data as gd->fdt_blob.
1056 U-Boot needs to get its device tree from somewhere. This can
1057 be done using one of the two options below:
1060 If this variable is defined, U-Boot will embed a device tree
1061 binary in its image. This device tree file should be in the
1062 board directory and called <soc>-<board>.dts. The binary file
1063 is then picked up in board_init_f() and made available through
1064 the global data structure as gd->blob.
1067 If this variable is defined, U-Boot will build a device tree
1068 binary. It will be called u-boot.dtb. Architecture-specific
1069 code will locate it at run-time. Generally this works by:
1071 cat u-boot.bin u-boot.dtb >image.bin
1073 and in fact, U-Boot does this for you, creating a file called
1074 u-boot-dtb.bin which is useful in the common case. You can
1075 still use the individual files if you need something more
1080 If this variable is defined, it enables watchdog
1081 support for the SoC. There must be support in the SoC
1082 specific code for a watchdog. For the 8xx and 8260
1083 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1084 register. When supported for a specific SoC is
1085 available, then no further board specific code should
1086 be needed to use it.
1089 When using a watchdog circuitry external to the used
1090 SoC, then define this variable and provide board
1091 specific code for the "hw_watchdog_reset" function.
1094 CONFIG_VERSION_VARIABLE
1095 If this variable is defined, an environment variable
1096 named "ver" is created by U-Boot showing the U-Boot
1097 version as printed by the "version" command.
1098 Any change to this variable will be reverted at the
1103 When CONFIG_CMD_DATE is selected, the type of the RTC
1104 has to be selected, too. Define exactly one of the
1107 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1108 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1109 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1110 CONFIG_RTC_MC146818 - use MC146818 RTC
1111 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1112 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1113 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1114 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1115 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1116 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1117 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1118 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1121 Note that if the RTC uses I2C, then the I2C interface
1122 must also be configured. See I2C Support, below.
1125 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1127 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1128 chip-ngpio pairs that tell the PCA953X driver the number of
1129 pins supported by a particular chip.
1131 Note that if the GPIO device uses I2C, then the I2C interface
1132 must also be configured. See I2C Support, below.
1134 - Timestamp Support:
1136 When CONFIG_TIMESTAMP is selected, the timestamp
1137 (date and time) of an image is printed by image
1138 commands like bootm or iminfo. This option is
1139 automatically enabled when you select CONFIG_CMD_DATE .
1141 - Partition Labels (disklabels) Supported:
1142 Zero or more of the following:
1143 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1144 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1145 Intel architecture, USB sticks, etc.
1146 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1147 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1148 bootloader. Note 2TB partition limit; see
1150 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1152 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1153 CONFIG_CMD_SCSI) you must configure support for at
1154 least one non-MTD partition type as well.
1157 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1158 board configurations files but used nowhere!
1160 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1161 be performed by calling the function
1162 ide_set_reset(int reset)
1163 which has to be defined in a board specific file
1168 Set this to enable ATAPI support.
1173 Set this to enable support for disks larger than 137GB
1174 Also look at CONFIG_SYS_64BIT_LBA.
1175 Whithout these , LBA48 support uses 32bit variables and will 'only'
1176 support disks up to 2.1TB.
1178 CONFIG_SYS_64BIT_LBA:
1179 When enabled, makes the IDE subsystem use 64bit sector addresses.
1183 At the moment only there is only support for the
1184 SYM53C8XX SCSI controller; define
1185 CONFIG_SCSI_SYM53C8XX to enable it.
1187 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1188 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1189 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1190 maximum numbers of LUNs, SCSI ID's and target
1192 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1194 The environment variable 'scsidevs' is set to the number of
1195 SCSI devices found during the last scan.
1197 - NETWORK Support (PCI):
1199 Support for Intel 8254x/8257x gigabit chips.
1202 Utility code for direct access to the SPI bus on Intel 8257x.
1203 This does not do anything useful unless you set at least one
1204 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1206 CONFIG_E1000_SPI_GENERIC
1207 Allow generic access to the SPI bus on the Intel 8257x, for
1208 example with the "sspi" command.
1211 Management command for E1000 devices. When used on devices
1212 with SPI support you can reprogram the EEPROM from U-Boot.
1214 CONFIG_E1000_FALLBACK_MAC
1215 default MAC for empty EEPROM after production.
1218 Support for Intel 82557/82559/82559ER chips.
1219 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1220 write routine for first time initialisation.
1223 Support for Digital 2114x chips.
1224 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1225 modem chip initialisation (KS8761/QS6611).
1228 Support for National dp83815 chips.
1231 Support for National dp8382[01] gigabit chips.
1233 - NETWORK Support (other):
1235 CONFIG_DRIVER_AT91EMAC
1236 Support for AT91RM9200 EMAC.
1239 Define this to use reduced MII inteface
1241 CONFIG_DRIVER_AT91EMAC_QUIET
1242 If this defined, the driver is quiet.
1243 The driver doen't show link status messages.
1245 CONFIG_CALXEDA_XGMAC
1246 Support for the Calxeda XGMAC device
1249 Support for SMSC's LAN91C96 chips.
1251 CONFIG_LAN91C96_BASE
1252 Define this to hold the physical address
1253 of the LAN91C96's I/O space
1255 CONFIG_LAN91C96_USE_32_BIT
1256 Define this to enable 32 bit addressing
1259 Support for SMSC's LAN91C111 chip
1261 CONFIG_SMC91111_BASE
1262 Define this to hold the physical address
1263 of the device (I/O space)
1265 CONFIG_SMC_USE_32_BIT
1266 Define this if data bus is 32 bits
1268 CONFIG_SMC_USE_IOFUNCS
1269 Define this to use i/o functions instead of macros
1270 (some hardware wont work with macros)
1272 CONFIG_DRIVER_TI_EMAC
1273 Support for davinci emac
1275 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1276 Define this if you have more then 3 PHYs.
1279 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1281 CONFIG_FTGMAC100_EGIGA
1282 Define this to use GE link update with gigabit PHY.
1283 Define this if FTGMAC100 is connected to gigabit PHY.
1284 If your system has 10/100 PHY only, it might not occur
1285 wrong behavior. Because PHY usually return timeout or
1286 useless data when polling gigabit status and gigabit
1287 control registers. This behavior won't affect the
1288 correctnessof 10/100 link speed update.
1291 Support for SMSC's LAN911x and LAN921x chips
1294 Define this to hold the physical address
1295 of the device (I/O space)
1297 CONFIG_SMC911X_32_BIT
1298 Define this if data bus is 32 bits
1300 CONFIG_SMC911X_16_BIT
1301 Define this if data bus is 16 bits. If your processor
1302 automatically converts one 32 bit word to two 16 bit
1303 words you may also try CONFIG_SMC911X_32_BIT.
1306 Support for Renesas on-chip Ethernet controller
1308 CONFIG_SH_ETHER_USE_PORT
1309 Define the number of ports to be used
1311 CONFIG_SH_ETHER_PHY_ADDR
1312 Define the ETH PHY's address
1314 CONFIG_SH_ETHER_CACHE_WRITEBACK
1315 If this option is set, the driver enables cache flush.
1319 Support TPM devices.
1322 Support for i2c bus TPM devices. Only one device
1323 per system is supported at this time.
1325 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1326 Define the the i2c bus number for the TPM device
1328 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1329 Define the TPM's address on the i2c bus
1331 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1332 Define the burst count bytes upper limit
1334 CONFIG_TPM_ATMEL_TWI
1335 Support for Atmel TWI TPM device. Requires I2C support.
1338 Support for generic parallel port TPM devices. Only one device
1339 per system is supported at this time.
1341 CONFIG_TPM_TIS_BASE_ADDRESS
1342 Base address where the generic TPM device is mapped
1343 to. Contemporary x86 systems usually map it at
1347 Add tpm monitor functions.
1348 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1349 provides monitor access to authorized functions.
1352 Define this to enable the TPM support library which provides
1353 functional interfaces to some TPM commands.
1354 Requires support for a TPM device.
1356 CONFIG_TPM_AUTH_SESSIONS
1357 Define this to enable authorized functions in the TPM library.
1358 Requires CONFIG_TPM and CONFIG_SHA1.
1361 At the moment only the UHCI host controller is
1362 supported (PIP405, MIP405, MPC5200); define
1363 CONFIG_USB_UHCI to enable it.
1364 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1365 and define CONFIG_USB_STORAGE to enable the USB
1368 Supported are USB Keyboards and USB Floppy drives
1370 MPC5200 USB requires additional defines:
1372 for 528 MHz Clock: 0x0001bbbb
1376 for differential drivers: 0x00001000
1377 for single ended drivers: 0x00005000
1378 for differential drivers on PSC3: 0x00000100
1379 for single ended drivers on PSC3: 0x00004100
1380 CONFIG_SYS_USB_EVENT_POLL
1381 May be defined to allow interrupt polling
1382 instead of using asynchronous interrupts
1384 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1385 txfilltuning field in the EHCI controller on reset.
1387 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1388 interval for usb hub power-on delay.(minimum 100msec)
1391 Define the below if you wish to use the USB console.
1392 Once firmware is rebuilt from a serial console issue the
1393 command "setenv stdin usbtty; setenv stdout usbtty" and
1394 attach your USB cable. The Unix command "dmesg" should print
1395 it has found a new device. The environment variable usbtty
1396 can be set to gserial or cdc_acm to enable your device to
1397 appear to a USB host as a Linux gserial device or a
1398 Common Device Class Abstract Control Model serial device.
1399 If you select usbtty = gserial you should be able to enumerate
1401 # modprobe usbserial vendor=0xVendorID product=0xProductID
1402 else if using cdc_acm, simply setting the environment
1403 variable usbtty to be cdc_acm should suffice. The following
1404 might be defined in YourBoardName.h
1407 Define this to build a UDC device
1410 Define this to have a tty type of device available to
1411 talk to the UDC device
1414 Define this to enable the high speed support for usb
1415 device and usbtty. If this feature is enabled, a routine
1416 int is_usbd_high_speed(void)
1417 also needs to be defined by the driver to dynamically poll
1418 whether the enumeration has succeded at high speed or full
1421 CONFIG_SYS_CONSOLE_IS_IN_ENV
1422 Define this if you want stdin, stdout &/or stderr to
1426 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1427 Derive USB clock from external clock "blah"
1428 - CONFIG_SYS_USB_EXTC_CLK 0x02
1430 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1431 Derive USB clock from brgclk
1432 - CONFIG_SYS_USB_BRG_CLK 0x04
1434 If you have a USB-IF assigned VendorID then you may wish to
1435 define your own vendor specific values either in BoardName.h
1436 or directly in usbd_vendor_info.h. If you don't define
1437 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1438 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1439 should pretend to be a Linux device to it's target host.
1441 CONFIG_USBD_MANUFACTURER
1442 Define this string as the name of your company for
1443 - CONFIG_USBD_MANUFACTURER "my company"
1445 CONFIG_USBD_PRODUCT_NAME
1446 Define this string as the name of your product
1447 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1449 CONFIG_USBD_VENDORID
1450 Define this as your assigned Vendor ID from the USB
1451 Implementors Forum. This *must* be a genuine Vendor ID
1452 to avoid polluting the USB namespace.
1453 - CONFIG_USBD_VENDORID 0xFFFF
1455 CONFIG_USBD_PRODUCTID
1456 Define this as the unique Product ID
1458 - CONFIG_USBD_PRODUCTID 0xFFFF
1460 Some USB device drivers may need to check USB cable attachment.
1461 In this case you can enable following config in BoardName.h:
1462 CONFIG_USB_CABLE_CHECK
1463 This enables function definition:
1464 - usb_cable_connected() in include/usb.h
1465 Implementation of this function is board-specific.
1467 - ULPI Layer Support:
1468 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1469 the generic ULPI layer. The generic layer accesses the ULPI PHY
1470 via the platform viewport, so you need both the genric layer and
1471 the viewport enabled. Currently only Chipidea/ARC based
1472 viewport is supported.
1473 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1474 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1475 If your ULPI phy needs a different reference clock than the
1476 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1477 the appropriate value in Hz.
1480 The MMC controller on the Intel PXA is supported. To
1481 enable this define CONFIG_MMC. The MMC can be
1482 accessed from the boot prompt by mapping the device
1483 to physical memory similar to flash. Command line is
1484 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1485 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1488 Support for Renesas on-chip MMCIF controller
1490 CONFIG_SH_MMCIF_ADDR
1491 Define the base address of MMCIF registers
1494 Define the clock frequency for MMCIF
1496 - USB Device Firmware Update (DFU) class support:
1498 This enables the USB portion of the DFU USB class
1501 This enables the command "dfu" which is used to have
1502 U-Boot create a DFU class device via USB. This command
1503 requires that the "dfu_alt_info" environment variable be
1504 set and define the alt settings to expose to the host.
1507 This enables support for exposing (e)MMC devices via DFU.
1510 This enables support for exposing NAND devices via DFU.
1513 This enables support for exposing RAM via DFU.
1514 Note: DFU spec refer to non-volatile memory usage, but
1515 allow usages beyond the scope of spec - here RAM usage,
1516 one that would help mostly the developer.
1518 CONFIG_SYS_DFU_DATA_BUF_SIZE
1519 Dfu transfer uses a buffer before writing data to the
1520 raw storage device. Make the size (in bytes) of this buffer
1521 configurable. The size of this buffer is also configurable
1522 through the "dfu_bufsiz" environment variable.
1524 CONFIG_SYS_DFU_MAX_FILE_SIZE
1525 When updating files rather than the raw storage device,
1526 we use a static buffer to copy the file into and then write
1527 the buffer once we've been given the whole file. Define
1528 this to the maximum filesize (in bytes) for the buffer.
1529 Default is 4 MiB if undefined.
1531 DFU_DEFAULT_POLL_TIMEOUT
1532 Poll timeout [ms], is the timeout a device can send to the
1533 host. The host must wait for this timeout before sending
1534 a subsequent DFU_GET_STATUS request to the device.
1536 DFU_MANIFEST_POLL_TIMEOUT
1537 Poll timeout [ms], which the device sends to the host when
1538 entering dfuMANIFEST state. Host waits this timeout, before
1539 sending again an USB request to the device.
1541 - Journaling Flash filesystem support:
1542 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1543 CONFIG_JFFS2_NAND_DEV
1544 Define these for a default partition on a NAND device
1546 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1547 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1548 Define these for a default partition on a NOR device
1550 CONFIG_SYS_JFFS_CUSTOM_PART
1551 Define this to create an own partition. You have to provide a
1552 function struct part_info* jffs2_part_info(int part_num)
1554 If you define only one JFFS2 partition you may also want to
1555 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1556 to disable the command chpart. This is the default when you
1557 have not defined a custom partition
1559 - FAT(File Allocation Table) filesystem write function support:
1562 Define this to enable support for saving memory data as a
1563 file in FAT formatted partition.
1565 This will also enable the command "fatwrite" enabling the
1566 user to write files to FAT.
1568 CBFS (Coreboot Filesystem) support
1571 Define this to enable support for reading from a Coreboot
1572 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1578 Define this to enable standard (PC-Style) keyboard
1582 Standard PC keyboard driver with US (is default) and
1583 GERMAN key layout (switch via environment 'keymap=de') support.
1584 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1585 for cfb_console. Supports cursor blinking.
1588 Enables a Chrome OS keyboard using the CROS_EC interface.
1589 This uses CROS_EC to communicate with a second microcontroller
1590 which provides key scans on request.
1595 Define this to enable video support (for output to
1598 CONFIG_VIDEO_CT69000
1600 Enable Chips & Technologies 69000 Video chip
1602 CONFIG_VIDEO_SMI_LYNXEM
1603 Enable Silicon Motion SMI 712/710/810 Video chip. The
1604 video output is selected via environment 'videoout'
1605 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1608 For the CT69000 and SMI_LYNXEM drivers, videomode is
1609 selected via environment 'videomode'. Two different ways
1611 - "videomode=num" 'num' is a standard LiLo mode numbers.
1612 Following standard modes are supported (* is default):
1614 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1615 -------------+---------------------------------------------
1616 8 bits | 0x301* 0x303 0x305 0x161 0x307
1617 15 bits | 0x310 0x313 0x316 0x162 0x319
1618 16 bits | 0x311 0x314 0x317 0x163 0x31A
1619 24 bits | 0x312 0x315 0x318 ? 0x31B
1620 -------------+---------------------------------------------
1621 (i.e. setenv videomode 317; saveenv; reset;)
1623 - "videomode=bootargs" all the video parameters are parsed
1624 from the bootargs. (See drivers/video/videomodes.c)
1627 CONFIG_VIDEO_SED13806
1628 Enable Epson SED13806 driver. This driver supports 8bpp
1629 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1630 or CONFIG_VIDEO_SED13806_16BPP
1633 Enable the Freescale DIU video driver. Reference boards for
1634 SOCs that have a DIU should define this macro to enable DIU
1635 support, and should also define these other macros:
1641 CONFIG_VIDEO_SW_CURSOR
1642 CONFIG_VGA_AS_SINGLE_DEVICE
1644 CONFIG_VIDEO_BMP_LOGO
1646 The DIU driver will look for the 'video-mode' environment
1647 variable, and if defined, enable the DIU as a console during
1648 boot. See the documentation file README.video for a
1649 description of this variable.
1653 Enable the VGA video / BIOS for x86. The alternative if you
1654 are using coreboot is to use the coreboot frame buffer
1661 Define this to enable a custom keyboard support.
1662 This simply calls drv_keyboard_init() which must be
1663 defined in your board-specific files.
1664 The only board using this so far is RBC823.
1666 - LCD Support: CONFIG_LCD
1668 Define this to enable LCD support (for output to LCD
1669 display); also select one of the supported displays
1670 by defining one of these:
1674 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1676 CONFIG_NEC_NL6448AC33:
1678 NEC NL6448AC33-18. Active, color, single scan.
1680 CONFIG_NEC_NL6448BC20
1682 NEC NL6448BC20-08. 6.5", 640x480.
1683 Active, color, single scan.
1685 CONFIG_NEC_NL6448BC33_54
1687 NEC NL6448BC33-54. 10.4", 640x480.
1688 Active, color, single scan.
1692 Sharp 320x240. Active, color, single scan.
1693 It isn't 16x9, and I am not sure what it is.
1695 CONFIG_SHARP_LQ64D341
1697 Sharp LQ64D341 display, 640x480.
1698 Active, color, single scan.
1702 HLD1045 display, 640x480.
1703 Active, color, single scan.
1707 Optrex CBL50840-2 NF-FW 99 22 M5
1709 Hitachi LMG6912RPFC-00T
1713 320x240. Black & white.
1715 Normally display is black on white background; define
1716 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1718 CONFIG_LCD_ALIGNMENT
1720 Normally the LCD is page-aligned (tyically 4KB). If this is
1721 defined then the LCD will be aligned to this value instead.
1722 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1723 here, since it is cheaper to change data cache settings on
1724 a per-section basis.
1726 CONFIG_CONSOLE_SCROLL_LINES
1728 When the console need to be scrolled, this is the number of
1729 lines to scroll by. It defaults to 1. Increasing this makes
1730 the console jump but can help speed up operation when scrolling
1735 Support drawing of RLE8-compressed bitmaps on the LCD.
1739 Enables an 'i2c edid' command which can read EDID
1740 information over I2C from an attached LCD display.
1742 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1744 If this option is set, the environment is checked for
1745 a variable "splashimage". If found, the usual display
1746 of logo, copyright and system information on the LCD
1747 is suppressed and the BMP image at the address
1748 specified in "splashimage" is loaded instead. The
1749 console is redirected to the "nulldev", too. This
1750 allows for a "silent" boot where a splash screen is
1751 loaded very quickly after power-on.
1753 CONFIG_SPLASHIMAGE_GUARD
1755 If this option is set, then U-Boot will prevent the environment
1756 variable "splashimage" from being set to a problematic address
1757 (see README.displaying-bmps).
1758 This option is useful for targets where, due to alignment
1759 restrictions, an improperly aligned BMP image will cause a data
1760 abort. If you think you will not have problems with unaligned
1761 accesses (for example because your toolchain prevents them)
1762 there is no need to set this option.
1764 CONFIG_SPLASH_SCREEN_ALIGN
1766 If this option is set the splash image can be freely positioned
1767 on the screen. Environment variable "splashpos" specifies the
1768 position as "x,y". If a positive number is given it is used as
1769 number of pixel from left/top. If a negative number is given it
1770 is used as number of pixel from right/bottom. You can also
1771 specify 'm' for centering the image.
1774 setenv splashpos m,m
1775 => image at center of screen
1777 setenv splashpos 30,20
1778 => image at x = 30 and y = 20
1780 setenv splashpos -10,m
1781 => vertically centered image
1782 at x = dspWidth - bmpWidth - 9
1784 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1786 If this option is set, additionally to standard BMP
1787 images, gzipped BMP images can be displayed via the
1788 splashscreen support or the bmp command.
1790 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1792 If this option is set, 8-bit RLE compressed BMP images
1793 can be displayed via the splashscreen support or the
1796 - Do compresssing for memory range:
1799 If this option is set, it would use zlib deflate method
1800 to compress the specified memory at its best effort.
1802 - Compression support:
1805 Enabled by default to support gzip compressed images.
1809 If this option is set, support for bzip2 compressed
1810 images is included. If not, only uncompressed and gzip
1811 compressed images are supported.
1813 NOTE: the bzip2 algorithm requires a lot of RAM, so
1814 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1819 If this option is set, support for lzma compressed
1822 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1823 requires an amount of dynamic memory that is given by the
1826 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1828 Where lc and lp stand for, respectively, Literal context bits
1829 and Literal pos bits.
1831 This value is upper-bounded by 14MB in the worst case. Anyway,
1832 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1833 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1834 a very small buffer.
1836 Use the lzmainfo tool to determinate the lc and lp values and
1837 then calculate the amount of needed dynamic memory (ensuring
1838 the appropriate CONFIG_SYS_MALLOC_LEN value).
1842 If this option is set, support for LZO compressed images
1848 The address of PHY on MII bus.
1850 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1852 The clock frequency of the MII bus
1856 If this option is set, support for speed/duplex
1857 detection of gigabit PHY is included.
1859 CONFIG_PHY_RESET_DELAY
1861 Some PHY like Intel LXT971A need extra delay after
1862 reset before any MII register access is possible.
1863 For such PHY, set this option to the usec delay
1864 required. (minimum 300usec for LXT971A)
1866 CONFIG_PHY_CMD_DELAY (ppc4xx)
1868 Some PHY like Intel LXT971A need extra delay after
1869 command issued before MII status register can be read
1879 Define a default value for Ethernet address to use
1880 for the respective Ethernet interface, in case this
1881 is not determined automatically.
1886 Define a default value for the IP address to use for
1887 the default Ethernet interface, in case this is not
1888 determined through e.g. bootp.
1889 (Environment variable "ipaddr")
1891 - Server IP address:
1894 Defines a default value for the IP address of a TFTP
1895 server to contact when using the "tftboot" command.
1896 (Environment variable "serverip")
1898 CONFIG_KEEP_SERVERADDR
1900 Keeps the server's MAC address, in the env 'serveraddr'
1901 for passing to bootargs (like Linux's netconsole option)
1903 - Gateway IP address:
1906 Defines a default value for the IP address of the
1907 default router where packets to other networks are
1909 (Environment variable "gatewayip")
1914 Defines a default value for the subnet mask (or
1915 routing prefix) which is used to determine if an IP
1916 address belongs to the local subnet or needs to be
1917 forwarded through a router.
1918 (Environment variable "netmask")
1920 - Multicast TFTP Mode:
1923 Defines whether you want to support multicast TFTP as per
1924 rfc-2090; for example to work with atftp. Lets lots of targets
1925 tftp down the same boot image concurrently. Note: the Ethernet
1926 driver in use must provide a function: mcast() to join/leave a
1929 - BOOTP Recovery Mode:
1930 CONFIG_BOOTP_RANDOM_DELAY
1932 If you have many targets in a network that try to
1933 boot using BOOTP, you may want to avoid that all
1934 systems send out BOOTP requests at precisely the same
1935 moment (which would happen for instance at recovery
1936 from a power failure, when all systems will try to
1937 boot, thus flooding the BOOTP server. Defining
1938 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1939 inserted before sending out BOOTP requests. The
1940 following delays are inserted then:
1942 1st BOOTP request: delay 0 ... 1 sec
1943 2nd BOOTP request: delay 0 ... 2 sec
1944 3rd BOOTP request: delay 0 ... 4 sec
1946 BOOTP requests: delay 0 ... 8 sec
1948 - DHCP Advanced Options:
1949 You can fine tune the DHCP functionality by defining
1950 CONFIG_BOOTP_* symbols:
1952 CONFIG_BOOTP_SUBNETMASK
1953 CONFIG_BOOTP_GATEWAY
1954 CONFIG_BOOTP_HOSTNAME
1955 CONFIG_BOOTP_NISDOMAIN
1956 CONFIG_BOOTP_BOOTPATH
1957 CONFIG_BOOTP_BOOTFILESIZE
1960 CONFIG_BOOTP_SEND_HOSTNAME
1961 CONFIG_BOOTP_NTPSERVER
1962 CONFIG_BOOTP_TIMEOFFSET
1963 CONFIG_BOOTP_VENDOREX
1964 CONFIG_BOOTP_MAY_FAIL
1966 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1967 environment variable, not the BOOTP server.
1969 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1970 after the configured retry count, the call will fail
1971 instead of starting over. This can be used to fail over
1972 to Link-local IP address configuration if the DHCP server
1975 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1976 serverip from a DHCP server, it is possible that more
1977 than one DNS serverip is offered to the client.
1978 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1979 serverip will be stored in the additional environment
1980 variable "dnsip2". The first DNS serverip is always
1981 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1984 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1985 to do a dynamic update of a DNS server. To do this, they
1986 need the hostname of the DHCP requester.
1987 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1988 of the "hostname" environment variable is passed as
1989 option 12 to the DHCP server.
1991 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1993 A 32bit value in microseconds for a delay between
1994 receiving a "DHCP Offer" and sending the "DHCP Request".
1995 This fixes a problem with certain DHCP servers that don't
1996 respond 100% of the time to a "DHCP request". E.g. On an
1997 AT91RM9200 processor running at 180MHz, this delay needed
1998 to be *at least* 15,000 usec before a Windows Server 2003
1999 DHCP server would reply 100% of the time. I recommend at
2000 least 50,000 usec to be safe. The alternative is to hope
2001 that one of the retries will be successful but note that
2002 the DHCP timeout and retry process takes a longer than
2005 - Link-local IP address negotiation:
2006 Negotiate with other link-local clients on the local network
2007 for an address that doesn't require explicit configuration.
2008 This is especially useful if a DHCP server cannot be guaranteed
2009 to exist in all environments that the device must operate.
2011 See doc/README.link-local for more information.
2014 CONFIG_CDP_DEVICE_ID
2016 The device id used in CDP trigger frames.
2018 CONFIG_CDP_DEVICE_ID_PREFIX
2020 A two character string which is prefixed to the MAC address
2025 A printf format string which contains the ascii name of
2026 the port. Normally is set to "eth%d" which sets
2027 eth0 for the first Ethernet, eth1 for the second etc.
2029 CONFIG_CDP_CAPABILITIES
2031 A 32bit integer which indicates the device capabilities;
2032 0x00000010 for a normal host which does not forwards.
2036 An ascii string containing the version of the software.
2040 An ascii string containing the name of the platform.
2044 A 32bit integer sent on the trigger.
2046 CONFIG_CDP_POWER_CONSUMPTION
2048 A 16bit integer containing the power consumption of the
2049 device in .1 of milliwatts.
2051 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2053 A byte containing the id of the VLAN.
2055 - Status LED: CONFIG_STATUS_LED
2057 Several configurations allow to display the current
2058 status using a LED. For instance, the LED will blink
2059 fast while running U-Boot code, stop blinking as
2060 soon as a reply to a BOOTP request was received, and
2061 start blinking slow once the Linux kernel is running
2062 (supported by a status LED driver in the Linux
2063 kernel). Defining CONFIG_STATUS_LED enables this
2069 The status LED can be connected to a GPIO pin.
2070 In such cases, the gpio_led driver can be used as a
2071 status LED backend implementation. Define CONFIG_GPIO_LED
2072 to include the gpio_led driver in the U-Boot binary.
2074 CONFIG_GPIO_LED_INVERTED_TABLE
2075 Some GPIO connected LEDs may have inverted polarity in which
2076 case the GPIO high value corresponds to LED off state and
2077 GPIO low value corresponds to LED on state.
2078 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2079 with a list of GPIO LEDs that have inverted polarity.
2081 - CAN Support: CONFIG_CAN_DRIVER
2083 Defining CONFIG_CAN_DRIVER enables CAN driver support
2084 on those systems that support this (optional)
2085 feature, like the TQM8xxL modules.
2087 - I2C Support: CONFIG_SYS_I2C
2089 This enable the NEW i2c subsystem, and will allow you to use
2090 i2c commands at the u-boot command line (as long as you set
2091 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2092 based realtime clock chips or other i2c devices. See
2093 common/cmd_i2c.c for a description of the command line
2096 ported i2c driver to the new framework:
2097 - drivers/i2c/soft_i2c.c:
2098 - activate first bus with CONFIG_SYS_I2C_SOFT define
2099 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2100 for defining speed and slave address
2101 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2102 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2103 for defining speed and slave address
2104 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2105 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2106 for defining speed and slave address
2107 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2108 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2109 for defining speed and slave address
2111 - drivers/i2c/fsl_i2c.c:
2112 - activate i2c driver with CONFIG_SYS_I2C_FSL
2113 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2114 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2115 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2117 - If your board supports a second fsl i2c bus, define
2118 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2119 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2120 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2123 - drivers/i2c/tegra_i2c.c:
2124 - activate this driver with CONFIG_SYS_I2C_TEGRA
2125 - This driver adds 4 i2c buses with a fix speed from
2126 100000 and the slave addr 0!
2128 - drivers/i2c/ppc4xx_i2c.c
2129 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2130 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2131 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2133 - drivers/i2c/i2c_mxc.c
2134 - activate this driver with CONFIG_SYS_I2C_MXC
2135 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2136 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2137 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2138 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2139 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2140 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2141 If thoses defines are not set, default value is 100000
2142 for speed, and 0 for slave.
2144 - drivers/i2c/rcar_i2c.c:
2145 - activate this driver with CONFIG_SYS_I2C_RCAR
2146 - This driver adds 4 i2c buses
2148 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2149 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2150 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2151 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2152 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2153 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2154 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2155 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2156 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2158 - drivers/i2c/sh_i2c.c:
2159 - activate this driver with CONFIG_SYS_I2C_SH
2160 - This driver adds from 2 to 5 i2c buses
2162 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2163 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2164 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2165 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2166 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2167 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2168 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2169 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2170 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2171 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2172 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2173 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2174 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2176 - drivers/i2c/omap24xx_i2c.c
2177 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2178 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2179 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2180 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2181 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2182 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2183 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2184 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2185 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2186 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2187 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2189 - drivers/i2c/zynq_i2c.c
2190 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2191 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2192 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2194 - drivers/i2c/s3c24x0_i2c.c:
2195 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2196 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2197 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2198 with a fix speed from 100000 and the slave addr 0!
2202 CONFIG_SYS_NUM_I2C_BUSES
2203 Hold the number of i2c busses you want to use. If you
2204 don't use/have i2c muxes on your i2c bus, this
2205 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2208 CONFIG_SYS_I2C_DIRECT_BUS
2209 define this, if you don't use i2c muxes on your hardware.
2210 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2213 CONFIG_SYS_I2C_MAX_HOPS
2214 define how many muxes are maximal consecutively connected
2215 on one i2c bus. If you not use i2c muxes, omit this
2218 CONFIG_SYS_I2C_BUSES
2219 hold a list of busses you want to use, only used if
2220 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2221 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2222 CONFIG_SYS_NUM_I2C_BUSES = 9:
2224 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2225 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2226 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2227 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2228 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2229 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2230 {1, {I2C_NULL_HOP}}, \
2231 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2232 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2236 bus 0 on adapter 0 without a mux
2237 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2238 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2239 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2240 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2241 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2242 bus 6 on adapter 1 without a mux
2243 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2244 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2246 If you do not have i2c muxes on your board, omit this define.
2248 - Legacy I2C Support: CONFIG_HARD_I2C
2250 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2251 provides the following compelling advantages:
2253 - more than one i2c adapter is usable
2254 - approved multibus support
2255 - better i2c mux support
2257 ** Please consider updating your I2C driver now. **
2259 These enable legacy I2C serial bus commands. Defining
2260 CONFIG_HARD_I2C will include the appropriate I2C driver
2261 for the selected CPU.
2263 This will allow you to use i2c commands at the u-boot
2264 command line (as long as you set CONFIG_CMD_I2C in
2265 CONFIG_COMMANDS) and communicate with i2c based realtime
2266 clock chips. See common/cmd_i2c.c for a description of the
2267 command line interface.
2269 CONFIG_HARD_I2C selects a hardware I2C controller.
2271 There are several other quantities that must also be
2272 defined when you define CONFIG_HARD_I2C.
2274 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2275 to be the frequency (in Hz) at which you wish your i2c bus
2276 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2277 the CPU's i2c node address).
2279 Now, the u-boot i2c code for the mpc8xx
2280 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2281 and so its address should therefore be cleared to 0 (See,
2282 eg, MPC823e User's Manual p.16-473). So, set
2283 CONFIG_SYS_I2C_SLAVE to 0.
2285 CONFIG_SYS_I2C_INIT_MPC5XXX
2287 When a board is reset during an i2c bus transfer
2288 chips might think that the current transfer is still
2289 in progress. Reset the slave devices by sending start
2290 commands until the slave device responds.
2292 That's all that's required for CONFIG_HARD_I2C.
2294 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2295 then the following macros need to be defined (examples are
2296 from include/configs/lwmon.h):
2300 (Optional). Any commands necessary to enable the I2C
2301 controller or configure ports.
2303 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2307 (Only for MPC8260 CPU). The I/O port to use (the code
2308 assumes both bits are on the same port). Valid values
2309 are 0..3 for ports A..D.
2313 The code necessary to make the I2C data line active
2314 (driven). If the data line is open collector, this
2317 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2321 The code necessary to make the I2C data line tri-stated
2322 (inactive). If the data line is open collector, this
2325 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2329 Code that returns true if the I2C data line is high,
2332 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2336 If <bit> is true, sets the I2C data line high. If it
2337 is false, it clears it (low).
2339 eg: #define I2C_SDA(bit) \
2340 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2341 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2345 If <bit> is true, sets the I2C clock line high. If it
2346 is false, it clears it (low).
2348 eg: #define I2C_SCL(bit) \
2349 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2350 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2354 This delay is invoked four times per clock cycle so this
2355 controls the rate of data transfer. The data rate thus
2356 is 1 / (I2C_DELAY * 4). Often defined to be something
2359 #define I2C_DELAY udelay(2)
2361 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2363 If your arch supports the generic GPIO framework (asm/gpio.h),
2364 then you may alternatively define the two GPIOs that are to be
2365 used as SCL / SDA. Any of the previous I2C_xxx macros will
2366 have GPIO-based defaults assigned to them as appropriate.
2368 You should define these to the GPIO value as given directly to
2369 the generic GPIO functions.
2371 CONFIG_SYS_I2C_INIT_BOARD
2373 When a board is reset during an i2c bus transfer
2374 chips might think that the current transfer is still
2375 in progress. On some boards it is possible to access
2376 the i2c SCLK line directly, either by using the
2377 processor pin as a GPIO or by having a second pin
2378 connected to the bus. If this option is defined a
2379 custom i2c_init_board() routine in boards/xxx/board.c
2380 is run early in the boot sequence.
2382 CONFIG_SYS_I2C_BOARD_LATE_INIT
2384 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2385 defined a custom i2c_board_late_init() routine in
2386 boards/xxx/board.c is run AFTER the operations in i2c_init()
2387 is completed. This callpoint can be used to unreset i2c bus
2388 using CPU i2c controller register accesses for CPUs whose i2c
2389 controller provide such a method. It is called at the end of
2390 i2c_init() to allow i2c_init operations to setup the i2c bus
2391 controller on the CPU (e.g. setting bus speed & slave address).
2393 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2395 This option enables configuration of bi_iic_fast[] flags
2396 in u-boot bd_info structure based on u-boot environment
2397 variable "i2cfast". (see also i2cfast)
2399 CONFIG_I2C_MULTI_BUS
2401 This option allows the use of multiple I2C buses, each of which
2402 must have a controller. At any point in time, only one bus is
2403 active. To switch to a different bus, use the 'i2c dev' command.
2404 Note that bus numbering is zero-based.
2406 CONFIG_SYS_I2C_NOPROBES
2408 This option specifies a list of I2C devices that will be skipped
2409 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2410 is set, specify a list of bus-device pairs. Otherwise, specify
2411 a 1D array of device addresses
2414 #undef CONFIG_I2C_MULTI_BUS
2415 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2417 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2419 #define CONFIG_I2C_MULTI_BUS
2420 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2422 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2424 CONFIG_SYS_SPD_BUS_NUM
2426 If defined, then this indicates the I2C bus number for DDR SPD.
2427 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2429 CONFIG_SYS_RTC_BUS_NUM
2431 If defined, then this indicates the I2C bus number for the RTC.
2432 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2434 CONFIG_SYS_DTT_BUS_NUM
2436 If defined, then this indicates the I2C bus number for the DTT.
2437 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2439 CONFIG_SYS_I2C_DTT_ADDR:
2441 If defined, specifies the I2C address of the DTT device.
2442 If not defined, then U-Boot uses predefined value for
2443 specified DTT device.
2445 CONFIG_SOFT_I2C_READ_REPEATED_START
2447 defining this will force the i2c_read() function in
2448 the soft_i2c driver to perform an I2C repeated start
2449 between writing the address pointer and reading the
2450 data. If this define is omitted the default behaviour
2451 of doing a stop-start sequence will be used. Most I2C
2452 devices can use either method, but some require one or
2455 - SPI Support: CONFIG_SPI
2457 Enables SPI driver (so far only tested with
2458 SPI EEPROM, also an instance works with Crystal A/D and
2459 D/As on the SACSng board)
2463 Enables the driver for SPI controller on SuperH. Currently
2464 only SH7757 is supported.
2468 Enables extended (16-bit) SPI EEPROM addressing.
2469 (symmetrical to CONFIG_I2C_X)
2473 Enables a software (bit-bang) SPI driver rather than
2474 using hardware support. This is a general purpose
2475 driver that only requires three general I/O port pins
2476 (two outputs, one input) to function. If this is
2477 defined, the board configuration must define several
2478 SPI configuration items (port pins to use, etc). For
2479 an example, see include/configs/sacsng.h.
2483 Enables a hardware SPI driver for general-purpose reads
2484 and writes. As with CONFIG_SOFT_SPI, the board configuration
2485 must define a list of chip-select function pointers.
2486 Currently supported on some MPC8xxx processors. For an
2487 example, see include/configs/mpc8349emds.h.
2491 Enables the driver for the SPI controllers on i.MX and MXC
2492 SoCs. Currently i.MX31/35/51 are supported.
2494 - FPGA Support: CONFIG_FPGA
2496 Enables FPGA subsystem.
2498 CONFIG_FPGA_<vendor>
2500 Enables support for specific chip vendors.
2503 CONFIG_FPGA_<family>
2505 Enables support for FPGA family.
2506 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2510 Specify the number of FPGA devices to support.
2512 CONFIG_SYS_FPGA_PROG_FEEDBACK
2514 Enable printing of hash marks during FPGA configuration.
2516 CONFIG_SYS_FPGA_CHECK_BUSY
2518 Enable checks on FPGA configuration interface busy
2519 status by the configuration function. This option
2520 will require a board or device specific function to
2525 If defined, a function that provides delays in the FPGA
2526 configuration driver.
2528 CONFIG_SYS_FPGA_CHECK_CTRLC
2529 Allow Control-C to interrupt FPGA configuration
2531 CONFIG_SYS_FPGA_CHECK_ERROR
2533 Check for configuration errors during FPGA bitfile
2534 loading. For example, abort during Virtex II
2535 configuration if the INIT_B line goes low (which
2536 indicated a CRC error).
2538 CONFIG_SYS_FPGA_WAIT_INIT
2540 Maximum time to wait for the INIT_B line to deassert
2541 after PROB_B has been deasserted during a Virtex II
2542 FPGA configuration sequence. The default time is 500
2545 CONFIG_SYS_FPGA_WAIT_BUSY
2547 Maximum time to wait for BUSY to deassert during
2548 Virtex II FPGA configuration. The default is 5 ms.
2550 CONFIG_SYS_FPGA_WAIT_CONFIG
2552 Time to wait after FPGA configuration. The default is
2555 - Configuration Management:
2558 If defined, this string will be added to the U-Boot
2559 version information (U_BOOT_VERSION)
2561 - Vendor Parameter Protection:
2563 U-Boot considers the values of the environment
2564 variables "serial#" (Board Serial Number) and
2565 "ethaddr" (Ethernet Address) to be parameters that
2566 are set once by the board vendor / manufacturer, and
2567 protects these variables from casual modification by
2568 the user. Once set, these variables are read-only,
2569 and write or delete attempts are rejected. You can
2570 change this behaviour:
2572 If CONFIG_ENV_OVERWRITE is #defined in your config
2573 file, the write protection for vendor parameters is
2574 completely disabled. Anybody can change or delete
2577 Alternatively, if you #define _both_ CONFIG_ETHADDR
2578 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2579 Ethernet address is installed in the environment,
2580 which can be changed exactly ONCE by the user. [The
2581 serial# is unaffected by this, i. e. it remains
2584 The same can be accomplished in a more flexible way
2585 for any variable by configuring the type of access
2586 to allow for those variables in the ".flags" variable
2587 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2592 Define this variable to enable the reservation of
2593 "protected RAM", i. e. RAM which is not overwritten
2594 by U-Boot. Define CONFIG_PRAM to hold the number of
2595 kB you want to reserve for pRAM. You can overwrite
2596 this default value by defining an environment
2597 variable "pram" to the number of kB you want to
2598 reserve. Note that the board info structure will
2599 still show the full amount of RAM. If pRAM is
2600 reserved, a new environment variable "mem" will
2601 automatically be defined to hold the amount of
2602 remaining RAM in a form that can be passed as boot
2603 argument to Linux, for instance like that:
2605 setenv bootargs ... mem=\${mem}
2608 This way you can tell Linux not to use this memory,
2609 either, which results in a memory region that will
2610 not be affected by reboots.
2612 *WARNING* If your board configuration uses automatic
2613 detection of the RAM size, you must make sure that
2614 this memory test is non-destructive. So far, the
2615 following board configurations are known to be
2618 IVMS8, IVML24, SPD8xx, TQM8xxL,
2619 HERMES, IP860, RPXlite, LWMON,
2622 - Access to physical memory region (> 4GB)
2623 Some basic support is provided for operations on memory not
2624 normally accessible to U-Boot - e.g. some architectures
2625 support access to more than 4GB of memory on 32-bit
2626 machines using physical address extension or similar.
2627 Define CONFIG_PHYSMEM to access this basic support, which
2628 currently only supports clearing the memory.
2633 Define this variable to stop the system in case of a
2634 fatal error, so that you have to reset it manually.
2635 This is probably NOT a good idea for an embedded
2636 system where you want the system to reboot
2637 automatically as fast as possible, but it may be
2638 useful during development since you can try to debug
2639 the conditions that lead to the situation.
2641 CONFIG_NET_RETRY_COUNT
2643 This variable defines the number of retries for
2644 network operations like ARP, RARP, TFTP, or BOOTP
2645 before giving up the operation. If not defined, a
2646 default value of 5 is used.
2650 Timeout waiting for an ARP reply in milliseconds.
2654 Timeout in milliseconds used in NFS protocol.
2655 If you encounter "ERROR: Cannot umount" in nfs command,
2656 try longer timeout such as
2657 #define CONFIG_NFS_TIMEOUT 10000UL
2659 - Command Interpreter:
2660 CONFIG_AUTO_COMPLETE
2662 Enable auto completion of commands using TAB.
2664 Note that this feature has NOT been implemented yet
2665 for the "hush" shell.
2668 CONFIG_SYS_HUSH_PARSER
2670 Define this variable to enable the "hush" shell (from
2671 Busybox) as command line interpreter, thus enabling
2672 powerful command line syntax like
2673 if...then...else...fi conditionals or `&&' and '||'
2674 constructs ("shell scripts").
2676 If undefined, you get the old, much simpler behaviour
2677 with a somewhat smaller memory footprint.
2680 CONFIG_SYS_PROMPT_HUSH_PS2
2682 This defines the secondary prompt string, which is
2683 printed when the command interpreter needs more input
2684 to complete a command. Usually "> ".
2688 In the current implementation, the local variables
2689 space and global environment variables space are
2690 separated. Local variables are those you define by
2691 simply typing `name=value'. To access a local
2692 variable later on, you have write `$name' or
2693 `${name}'; to execute the contents of a variable
2694 directly type `$name' at the command prompt.
2696 Global environment variables are those you use
2697 setenv/printenv to work with. To run a command stored
2698 in such a variable, you need to use the run command,
2699 and you must not use the '$' sign to access them.
2701 To store commands and special characters in a
2702 variable, please use double quotation marks
2703 surrounding the whole text of the variable, instead
2704 of the backslashes before semicolons and special
2707 - Commandline Editing and History:
2708 CONFIG_CMDLINE_EDITING
2710 Enable editing and History functions for interactive
2711 commandline input operations
2713 - Default Environment:
2714 CONFIG_EXTRA_ENV_SETTINGS
2716 Define this to contain any number of null terminated
2717 strings (variable = value pairs) that will be part of
2718 the default environment compiled into the boot image.
2720 For example, place something like this in your
2721 board's config file:
2723 #define CONFIG_EXTRA_ENV_SETTINGS \
2727 Warning: This method is based on knowledge about the
2728 internal format how the environment is stored by the
2729 U-Boot code. This is NOT an official, exported
2730 interface! Although it is unlikely that this format
2731 will change soon, there is no guarantee either.
2732 You better know what you are doing here.
2734 Note: overly (ab)use of the default environment is
2735 discouraged. Make sure to check other ways to preset
2736 the environment like the "source" command or the
2739 CONFIG_ENV_VARS_UBOOT_CONFIG
2741 Define this in order to add variables describing the
2742 U-Boot build configuration to the default environment.
2743 These will be named arch, cpu, board, vendor, and soc.
2745 Enabling this option will cause the following to be defined:
2753 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2755 Define this in order to add variables describing certain
2756 run-time determined information about the hardware to the
2757 environment. These will be named board_name, board_rev.
2759 CONFIG_DELAY_ENVIRONMENT
2761 Normally the environment is loaded when the board is
2762 intialised so that it is available to U-Boot. This inhibits
2763 that so that the environment is not available until
2764 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2765 this is instead controlled by the value of
2766 /config/load-environment.
2768 - DataFlash Support:
2769 CONFIG_HAS_DATAFLASH
2771 Defining this option enables DataFlash features and
2772 allows to read/write in Dataflash via the standard
2775 - Serial Flash support
2778 Defining this option enables SPI flash commands
2779 'sf probe/read/write/erase/update'.
2781 Usage requires an initial 'probe' to define the serial
2782 flash parameters, followed by read/write/erase/update
2785 The following defaults may be provided by the platform
2786 to handle the common case when only a single serial
2787 flash is present on the system.
2789 CONFIG_SF_DEFAULT_BUS Bus identifier
2790 CONFIG_SF_DEFAULT_CS Chip-select
2791 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2792 CONFIG_SF_DEFAULT_SPEED in Hz
2796 Define this option to include a destructive SPI flash
2799 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2801 Define this option to use the Bank addr/Extended addr
2802 support on SPI flashes which has size > 16Mbytes.
2804 CONFIG_SF_DUAL_FLASH Dual flash memories
2806 Define this option to use dual flash support where two flash
2807 memories can be connected with a given cs line.
2808 currently Xilinx Zynq qspi support these type of connections.
2810 - SystemACE Support:
2813 Adding this option adds support for Xilinx SystemACE
2814 chips attached via some sort of local bus. The address
2815 of the chip must also be defined in the
2816 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2818 #define CONFIG_SYSTEMACE
2819 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2821 When SystemACE support is added, the "ace" device type
2822 becomes available to the fat commands, i.e. fatls.
2824 - TFTP Fixed UDP Port:
2827 If this is defined, the environment variable tftpsrcp
2828 is used to supply the TFTP UDP source port value.
2829 If tftpsrcp isn't defined, the normal pseudo-random port
2830 number generator is used.
2832 Also, the environment variable tftpdstp is used to supply
2833 the TFTP UDP destination port value. If tftpdstp isn't
2834 defined, the normal port 69 is used.
2836 The purpose for tftpsrcp is to allow a TFTP server to
2837 blindly start the TFTP transfer using the pre-configured
2838 target IP address and UDP port. This has the effect of
2839 "punching through" the (Windows XP) firewall, allowing
2840 the remainder of the TFTP transfer to proceed normally.
2841 A better solution is to properly configure the firewall,
2842 but sometimes that is not allowed.
2847 This enables a generic 'hash' command which can produce
2848 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2852 Enable the hash verify command (hash -v). This adds to code
2855 CONFIG_SHA1 - support SHA1 hashing
2856 CONFIG_SHA256 - support SHA256 hashing
2858 Note: There is also a sha1sum command, which should perhaps
2859 be deprecated in favour of 'hash sha1'.
2861 - Freescale i.MX specific commands:
2862 CONFIG_CMD_HDMIDETECT
2863 This enables 'hdmidet' command which returns true if an
2864 HDMI monitor is detected. This command is i.MX 6 specific.
2867 This enables the 'bmode' (bootmode) command for forcing
2868 a boot from specific media.
2870 This is useful for forcing the ROM's usb downloader to
2871 activate upon a watchdog reset which is nice when iterating
2872 on U-Boot. Using the reset button or running bmode normal
2873 will set it back to normal. This command currently
2874 supports i.MX53 and i.MX6.
2879 This enables the RSA algorithm used for FIT image verification
2880 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2882 The signing part is build into mkimage regardless of this
2885 - bootcount support:
2886 CONFIG_BOOTCOUNT_LIMIT
2888 This enables the bootcounter support, see:
2889 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2892 enable special bootcounter support on at91sam9xe based boards.
2894 enable special bootcounter support on blackfin based boards.
2896 enable special bootcounter support on da850 based boards.
2897 CONFIG_BOOTCOUNT_RAM
2898 enable support for the bootcounter in RAM
2899 CONFIG_BOOTCOUNT_I2C
2900 enable support for the bootcounter on an i2c (like RTC) device.
2901 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2902 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2904 CONFIG_BOOTCOUNT_ALEN = address len
2906 - Show boot progress:
2907 CONFIG_SHOW_BOOT_PROGRESS
2909 Defining this option allows to add some board-
2910 specific code (calling a user-provided function
2911 "show_boot_progress(int)") that enables you to show
2912 the system's boot progress on some display (for
2913 example, some LED's) on your board. At the moment,
2914 the following checkpoints are implemented:
2916 - Detailed boot stage timing
2918 Define this option to get detailed timing of each stage
2919 of the boot process.
2921 CONFIG_BOOTSTAGE_USER_COUNT
2922 This is the number of available user bootstage records.
2923 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2924 a new ID will be allocated from this stash. If you exceed
2925 the limit, recording will stop.
2927 CONFIG_BOOTSTAGE_REPORT
2928 Define this to print a report before boot, similar to this:
2930 Timer summary in microseconds:
2933 3,575,678 3,575,678 board_init_f start
2934 3,575,695 17 arch_cpu_init A9
2935 3,575,777 82 arch_cpu_init done
2936 3,659,598 83,821 board_init_r start
2937 3,910,375 250,777 main_loop
2938 29,916,167 26,005,792 bootm_start
2939 30,361,327 445,160 start_kernel
2941 CONFIG_CMD_BOOTSTAGE
2942 Add a 'bootstage' command which supports printing a report
2943 and un/stashing of bootstage data.
2945 CONFIG_BOOTSTAGE_FDT
2946 Stash the bootstage information in the FDT. A root 'bootstage'
2947 node is created with each bootstage id as a child. Each child
2948 has a 'name' property and either 'mark' containing the
2949 mark time in microsecond, or 'accum' containing the
2950 accumulated time for that bootstage id in microseconds.
2955 name = "board_init_f";
2964 Code in the Linux kernel can find this in /proc/devicetree.
2966 Legacy uImage format:
2969 1 common/cmd_bootm.c before attempting to boot an image
2970 -1 common/cmd_bootm.c Image header has bad magic number
2971 2 common/cmd_bootm.c Image header has correct magic number
2972 -2 common/cmd_bootm.c Image header has bad checksum
2973 3 common/cmd_bootm.c Image header has correct checksum
2974 -3 common/cmd_bootm.c Image data has bad checksum
2975 4 common/cmd_bootm.c Image data has correct checksum
2976 -4 common/cmd_bootm.c Image is for unsupported architecture
2977 5 common/cmd_bootm.c Architecture check OK
2978 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2979 6 common/cmd_bootm.c Image Type check OK
2980 -6 common/cmd_bootm.c gunzip uncompression error
2981 -7 common/cmd_bootm.c Unimplemented compression type
2982 7 common/cmd_bootm.c Uncompression OK
2983 8 common/cmd_bootm.c No uncompress/copy overwrite error
2984 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2986 9 common/image.c Start initial ramdisk verification
2987 -10 common/image.c Ramdisk header has bad magic number
2988 -11 common/image.c Ramdisk header has bad checksum
2989 10 common/image.c Ramdisk header is OK
2990 -12 common/image.c Ramdisk data has bad checksum
2991 11 common/image.c Ramdisk data has correct checksum
2992 12 common/image.c Ramdisk verification complete, start loading
2993 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2994 13 common/image.c Start multifile image verification
2995 14 common/image.c No initial ramdisk, no multifile, continue.
2997 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2999 -30 arch/powerpc/lib/board.c Fatal error, hang the system
3000 -31 post/post.c POST test failed, detected by post_output_backlog()
3001 -32 post/post.c POST test failed, detected by post_run_single()
3003 34 common/cmd_doc.c before loading a Image from a DOC device
3004 -35 common/cmd_doc.c Bad usage of "doc" command
3005 35 common/cmd_doc.c correct usage of "doc" command
3006 -36 common/cmd_doc.c No boot device
3007 36 common/cmd_doc.c correct boot device
3008 -37 common/cmd_doc.c Unknown Chip ID on boot device
3009 37 common/cmd_doc.c correct chip ID found, device available
3010 -38 common/cmd_doc.c Read Error on boot device
3011 38 common/cmd_doc.c reading Image header from DOC device OK
3012 -39 common/cmd_doc.c Image header has bad magic number
3013 39 common/cmd_doc.c Image header has correct magic number
3014 -40 common/cmd_doc.c Error reading Image from DOC device
3015 40 common/cmd_doc.c Image header has correct magic number
3016 41 common/cmd_ide.c before loading a Image from a IDE device
3017 -42 common/cmd_ide.c Bad usage of "ide" command
3018 42 common/cmd_ide.c correct usage of "ide" command
3019 -43 common/cmd_ide.c No boot device
3020 43 common/cmd_ide.c boot device found
3021 -44 common/cmd_ide.c Device not available
3022 44 common/cmd_ide.c Device available
3023 -45 common/cmd_ide.c wrong partition selected
3024 45 common/cmd_ide.c partition selected
3025 -46 common/cmd_ide.c Unknown partition table
3026 46 common/cmd_ide.c valid partition table found
3027 -47 common/cmd_ide.c Invalid partition type
3028 47 common/cmd_ide.c correct partition type
3029 -48 common/cmd_ide.c Error reading Image Header on boot device
3030 48 common/cmd_ide.c reading Image Header from IDE device OK
3031 -49 common/cmd_ide.c Image header has bad magic number
3032 49 common/cmd_ide.c Image header has correct magic number
3033 -50 common/cmd_ide.c Image header has bad checksum
3034 50 common/cmd_ide.c Image header has correct checksum
3035 -51 common/cmd_ide.c Error reading Image from IDE device
3036 51 common/cmd_ide.c reading Image from IDE device OK
3037 52 common/cmd_nand.c before loading a Image from a NAND device
3038 -53 common/cmd_nand.c Bad usage of "nand" command
3039 53 common/cmd_nand.c correct usage of "nand" command
3040 -54 common/cmd_nand.c No boot device
3041 54 common/cmd_nand.c boot device found
3042 -55 common/cmd_nand.c Unknown Chip ID on boot device
3043 55 common/cmd_nand.c correct chip ID found, device available
3044 -56 common/cmd_nand.c Error reading Image Header on boot device
3045 56 common/cmd_nand.c reading Image Header from NAND device OK
3046 -57 common/cmd_nand.c Image header has bad magic number
3047 57 common/cmd_nand.c Image header has correct magic number
3048 -58 common/cmd_nand.c Error reading Image from NAND device
3049 58 common/cmd_nand.c reading Image from NAND device OK
3051 -60 common/env_common.c Environment has a bad CRC, using default
3053 64 net/eth.c starting with Ethernet configuration.
3054 -64 net/eth.c no Ethernet found.
3055 65 net/eth.c Ethernet found.
3057 -80 common/cmd_net.c usage wrong
3058 80 common/cmd_net.c before calling NetLoop()
3059 -81 common/cmd_net.c some error in NetLoop() occurred
3060 81 common/cmd_net.c NetLoop() back without error
3061 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3062 82 common/cmd_net.c trying automatic boot
3063 83 common/cmd_net.c running "source" command
3064 -83 common/cmd_net.c some error in automatic boot or "source" command
3065 84 common/cmd_net.c end without errors
3070 100 common/cmd_bootm.c Kernel FIT Image has correct format
3071 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3072 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3073 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3074 102 common/cmd_bootm.c Kernel unit name specified
3075 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3076 103 common/cmd_bootm.c Found configuration node
3077 104 common/cmd_bootm.c Got kernel subimage node offset
3078 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3079 105 common/cmd_bootm.c Kernel subimage hash verification OK
3080 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3081 106 common/cmd_bootm.c Architecture check OK
3082 -106 common/cmd_bootm.c Kernel subimage has wrong type
3083 107 common/cmd_bootm.c Kernel subimage type OK
3084 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3085 108 common/cmd_bootm.c Got kernel subimage data/size
3086 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3087 -109 common/cmd_bootm.c Can't get kernel subimage type
3088 -110 common/cmd_bootm.c Can't get kernel subimage comp
3089 -111 common/cmd_bootm.c Can't get kernel subimage os
3090 -112 common/cmd_bootm.c Can't get kernel subimage load address
3091 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3093 120 common/image.c Start initial ramdisk verification
3094 -120 common/image.c Ramdisk FIT image has incorrect format
3095 121 common/image.c Ramdisk FIT image has correct format
3096 122 common/image.c No ramdisk subimage unit name, using configuration
3097 -122 common/image.c Can't get configuration for ramdisk subimage
3098 123 common/image.c Ramdisk unit name specified
3099 -124 common/image.c Can't get ramdisk subimage node offset
3100 125 common/image.c Got ramdisk subimage node offset
3101 -125 common/image.c Ramdisk subimage hash verification failed
3102 126 common/image.c Ramdisk subimage hash verification OK
3103 -126 common/image.c Ramdisk subimage for unsupported architecture
3104 127 common/image.c Architecture check OK
3105 -127 common/image.c Can't get ramdisk subimage data/size
3106 128 common/image.c Got ramdisk subimage data/size
3107 129 common/image.c Can't get ramdisk load address
3108 -129 common/image.c Got ramdisk load address
3110 -130 common/cmd_doc.c Incorrect FIT image format
3111 131 common/cmd_doc.c FIT image format OK
3113 -140 common/cmd_ide.c Incorrect FIT image format
3114 141 common/cmd_ide.c FIT image format OK
3116 -150 common/cmd_nand.c Incorrect FIT image format
3117 151 common/cmd_nand.c FIT image format OK
3119 - FIT image support:
3121 Enable support for the FIT uImage format.
3123 CONFIG_FIT_BEST_MATCH
3124 When no configuration is explicitly selected, default to the
3125 one whose fdt's compatibility field best matches that of
3126 U-Boot itself. A match is considered "best" if it matches the
3127 most specific compatibility entry of U-Boot's fdt's root node.
3128 The order of entries in the configuration's fdt is ignored.
3130 CONFIG_FIT_SIGNATURE
3131 This option enables signature verification of FIT uImages,
3132 using a hash signed and verified using RSA. See
3133 doc/uImage.FIT/signature.txt for more details.
3135 - Standalone program support:
3136 CONFIG_STANDALONE_LOAD_ADDR
3138 This option defines a board specific value for the
3139 address where standalone program gets loaded, thus
3140 overwriting the architecture dependent default
3143 - Frame Buffer Address:
3146 Define CONFIG_FB_ADDR if you want to use specific
3147 address for frame buffer. This is typically the case
3148 when using a graphics controller has separate video
3149 memory. U-Boot will then place the frame buffer at
3150 the given address instead of dynamically reserving it
3151 in system RAM by calling lcd_setmem(), which grabs
3152 the memory for the frame buffer depending on the
3153 configured panel size.
3155 Please see board_init_f function.
3157 - Automatic software updates via TFTP server
3159 CONFIG_UPDATE_TFTP_CNT_MAX
3160 CONFIG_UPDATE_TFTP_MSEC_MAX
3162 These options enable and control the auto-update feature;
3163 for a more detailed description refer to doc/README.update.
3165 - MTD Support (mtdparts command, UBI support)
3168 Adds the MTD device infrastructure from the Linux kernel.
3169 Needed for mtdparts command support.
3171 CONFIG_MTD_PARTITIONS
3173 Adds the MTD partitioning infrastructure from the Linux
3174 kernel. Needed for UBI support.
3179 Adds commands for interacting with MTD partitions formatted
3180 with the UBI flash translation layer
3182 Requires also defining CONFIG_RBTREE
3184 CONFIG_UBI_SILENCE_MSG
3186 Make the verbose messages from UBI stop printing. This leaves
3187 warnings and errors enabled.
3192 Adds commands for interacting with UBI volumes formatted as
3193 UBIFS. UBIFS is read-only in u-boot.
3195 Requires UBI support as well as CONFIG_LZO
3197 CONFIG_UBIFS_SILENCE_MSG
3199 Make the verbose messages from UBIFS stop printing. This leaves
3200 warnings and errors enabled.
3204 Enable building of SPL globally.
3207 LDSCRIPT for linking the SPL binary.
3209 CONFIG_SPL_MAX_FOOTPRINT
3210 Maximum size in memory allocated to the SPL, BSS included.
3211 When defined, the linker checks that the actual memory
3212 used by SPL from _start to __bss_end does not exceed it.
3213 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3214 must not be both defined at the same time.
3217 Maximum size of the SPL image (text, data, rodata, and
3218 linker lists sections), BSS excluded.
3219 When defined, the linker checks that the actual size does
3222 CONFIG_SPL_TEXT_BASE
3223 TEXT_BASE for linking the SPL binary.
3225 CONFIG_SPL_RELOC_TEXT_BASE
3226 Address to relocate to. If unspecified, this is equal to
3227 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3229 CONFIG_SPL_BSS_START_ADDR
3230 Link address for the BSS within the SPL binary.
3232 CONFIG_SPL_BSS_MAX_SIZE
3233 Maximum size in memory allocated to the SPL BSS.
3234 When defined, the linker checks that the actual memory used
3235 by SPL from __bss_start to __bss_end does not exceed it.
3236 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3237 must not be both defined at the same time.
3240 Adress of the start of the stack SPL will use
3242 CONFIG_SPL_RELOC_STACK
3243 Adress of the start of the stack SPL will use after
3244 relocation. If unspecified, this is equal to
3247 CONFIG_SYS_SPL_MALLOC_START
3248 Starting address of the malloc pool used in SPL.
3250 CONFIG_SYS_SPL_MALLOC_SIZE
3251 The size of the malloc pool used in SPL.
3253 CONFIG_SPL_FRAMEWORK
3254 Enable the SPL framework under common/. This framework
3255 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3256 NAND loading of the Linux Kernel.
3258 CONFIG_SPL_DISPLAY_PRINT
3259 For ARM, enable an optional function to print more information
3260 about the running system.
3262 CONFIG_SPL_INIT_MINIMAL
3263 Arch init code should be built for a very small image
3265 CONFIG_SPL_LIBCOMMON_SUPPORT
3266 Support for common/libcommon.o in SPL binary
3268 CONFIG_SPL_LIBDISK_SUPPORT
3269 Support for disk/libdisk.o in SPL binary
3271 CONFIG_SPL_I2C_SUPPORT
3272 Support for drivers/i2c/libi2c.o in SPL binary
3274 CONFIG_SPL_GPIO_SUPPORT
3275 Support for drivers/gpio/libgpio.o in SPL binary
3277 CONFIG_SPL_MMC_SUPPORT
3278 Support for drivers/mmc/libmmc.o in SPL binary
3280 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3281 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3282 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3283 Address, size and partition on the MMC to load U-Boot from
3284 when the MMC is being used in raw mode.
3286 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3287 Sector to load kernel uImage from when MMC is being
3288 used in raw mode (for Falcon mode)
3290 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3291 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3292 Sector and number of sectors to load kernel argument
3293 parameters from when MMC is being used in raw mode
3296 CONFIG_SPL_FAT_SUPPORT
3297 Support for fs/fat/libfat.o in SPL binary
3299 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3300 Filename to read to load U-Boot when reading from FAT
3302 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3303 Filename to read to load kernel uImage when reading
3304 from FAT (for Falcon mode)
3306 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3307 Filename to read to load kernel argument parameters
3308 when reading from FAT (for Falcon mode)
3310 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3311 Set this for NAND SPL on PPC mpc83xx targets, so that
3312 start.S waits for the rest of the SPL to load before
3313 continuing (the hardware starts execution after just
3314 loading the first page rather than the full 4K).
3316 CONFIG_SPL_NAND_BASE
3317 Include nand_base.c in the SPL. Requires
3318 CONFIG_SPL_NAND_DRIVERS.
3320 CONFIG_SPL_NAND_DRIVERS
3321 SPL uses normal NAND drivers, not minimal drivers.
3324 Include standard software ECC in the SPL
3326 CONFIG_SPL_NAND_SIMPLE
3327 Support for NAND boot using simple NAND drivers that
3328 expose the cmd_ctrl() interface.
3330 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3331 Set for the SPL on PPC mpc8xxx targets, support for
3332 drivers/ddr/fsl/libddr.o in SPL binary.
3334 CONFIG_SPL_COMMON_INIT_DDR
3335 Set for common ddr init with serial presence detect in
3338 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3339 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3340 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3341 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3342 CONFIG_SYS_NAND_ECCBYTES
3343 Defines the size and behavior of the NAND that SPL uses
3346 CONFIG_SPL_NAND_BOOT
3347 Add support NAND boot
3349 CONFIG_SYS_NAND_U_BOOT_OFFS
3350 Location in NAND to read U-Boot from
3352 CONFIG_SYS_NAND_U_BOOT_DST
3353 Location in memory to load U-Boot to
3355 CONFIG_SYS_NAND_U_BOOT_SIZE
3356 Size of image to load
3358 CONFIG_SYS_NAND_U_BOOT_START
3359 Entry point in loaded image to jump to
3361 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3362 Define this if you need to first read the OOB and then the
3363 data. This is used for example on davinci plattforms.
3365 CONFIG_SPL_OMAP3_ID_NAND
3366 Support for an OMAP3-specific set of functions to return the
3367 ID and MFR of the first attached NAND chip, if present.
3369 CONFIG_SPL_SERIAL_SUPPORT
3370 Support for drivers/serial/libserial.o in SPL binary
3372 CONFIG_SPL_SPI_FLASH_SUPPORT
3373 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3375 CONFIG_SPL_SPI_SUPPORT
3376 Support for drivers/spi/libspi.o in SPL binary
3378 CONFIG_SPL_RAM_DEVICE
3379 Support for running image already present in ram, in SPL binary
3381 CONFIG_SPL_LIBGENERIC_SUPPORT
3382 Support for lib/libgeneric.o in SPL binary
3384 CONFIG_SPL_ENV_SUPPORT
3385 Support for the environment operating in SPL binary
3387 CONFIG_SPL_NET_SUPPORT
3388 Support for the net/libnet.o in SPL binary.
3389 It conflicts with SPL env from storage medium specified by
3390 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3393 Image offset to which the SPL should be padded before appending
3394 the SPL payload. By default, this is defined as
3395 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3396 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3397 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3400 Final target image containing SPL and payload. Some SPLs
3401 use an arch-specific makefile fragment instead, for
3402 example if more than one image needs to be produced.
3404 CONFIG_FIT_SPL_PRINT
3405 Printing information about a FIT image adds quite a bit of
3406 code to SPL. So this is normally disabled in SPL. Use this
3407 option to re-enable it. This will affect the output of the
3408 bootm command when booting a FIT image.
3412 Enable building of TPL globally.
3415 Image offset to which the TPL should be padded before appending
3416 the TPL payload. By default, this is defined as
3417 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3418 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3419 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3424 [so far only for SMDK2400 boards]
3426 - Modem support enable:
3427 CONFIG_MODEM_SUPPORT
3429 - RTS/CTS Flow control enable:
3432 - Modem debug support:
3433 CONFIG_MODEM_SUPPORT_DEBUG
3435 Enables debugging stuff (char screen[1024], dbg())
3436 for modem support. Useful only with BDI2000.
3438 - Interrupt support (PPC):
3440 There are common interrupt_init() and timer_interrupt()
3441 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3442 for CPU specific initialization. interrupt_init_cpu()
3443 should set decrementer_count to appropriate value. If
3444 CPU resets decrementer automatically after interrupt
3445 (ppc4xx) it should set decrementer_count to zero.
3446 timer_interrupt() calls timer_interrupt_cpu() for CPU
3447 specific handling. If board has watchdog / status_led
3448 / other_activity_monitor it works automatically from
3449 general timer_interrupt().
3453 In the target system modem support is enabled when a
3454 specific key (key combination) is pressed during
3455 power-on. Otherwise U-Boot will boot normally
3456 (autoboot). The key_pressed() function is called from
3457 board_init(). Currently key_pressed() is a dummy
3458 function, returning 1 and thus enabling modem
3461 If there are no modem init strings in the
3462 environment, U-Boot proceed to autoboot; the
3463 previous output (banner, info printfs) will be
3466 See also: doc/README.Modem
3468 Board initialization settings:
3469 ------------------------------
3471 During Initialization u-boot calls a number of board specific functions
3472 to allow the preparation of board specific prerequisites, e.g. pin setup
3473 before drivers are initialized. To enable these callbacks the
3474 following configuration macros have to be defined. Currently this is
3475 architecture specific, so please check arch/your_architecture/lib/board.c
3476 typically in board_init_f() and board_init_r().
3478 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3479 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3480 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3481 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3483 Configuration Settings:
3484 -----------------------
3486 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3487 Optionally it can be defined to support 64-bit memory commands.
3489 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3490 undefine this when you're short of memory.
3492 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3493 width of the commands listed in the 'help' command output.
3495 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3496 prompt for user input.
3498 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3500 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3502 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3504 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3505 the application (usually a Linux kernel) when it is
3508 - CONFIG_SYS_BAUDRATE_TABLE:
3509 List of legal baudrate settings for this board.
3511 - CONFIG_SYS_CONSOLE_INFO_QUIET
3512 Suppress display of console information at boot.
3514 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3515 If the board specific function
3516 extern int overwrite_console (void);
3517 returns 1, the stdin, stderr and stdout are switched to the
3518 serial port, else the settings in the environment are used.
3520 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3521 Enable the call to overwrite_console().
3523 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3524 Enable overwrite of previous console environment settings.
3526 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3527 Begin and End addresses of the area used by the
3530 - CONFIG_SYS_ALT_MEMTEST:
3531 Enable an alternate, more extensive memory test.
3533 - CONFIG_SYS_MEMTEST_SCRATCH:
3534 Scratch address used by the alternate memory test
3535 You only need to set this if address zero isn't writeable
3537 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3538 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3539 this specified memory area will get subtracted from the top
3540 (end) of RAM and won't get "touched" at all by U-Boot. By
3541 fixing up gd->ram_size the Linux kernel should gets passed
3542 the now "corrected" memory size and won't touch it either.
3543 This should work for arch/ppc and arch/powerpc. Only Linux
3544 board ports in arch/powerpc with bootwrapper support that
3545 recalculate the memory size from the SDRAM controller setup
3546 will have to get fixed in Linux additionally.
3548 This option can be used as a workaround for the 440EPx/GRx
3549 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3552 WARNING: Please make sure that this value is a multiple of
3553 the Linux page size (normally 4k). If this is not the case,
3554 then the end address of the Linux memory will be located at a
3555 non page size aligned address and this could cause major
3558 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3559 Enable temporary baudrate change while serial download
3561 - CONFIG_SYS_SDRAM_BASE:
3562 Physical start address of SDRAM. _Must_ be 0 here.
3564 - CONFIG_SYS_MBIO_BASE:
3565 Physical start address of Motherboard I/O (if using a
3568 - CONFIG_SYS_FLASH_BASE:
3569 Physical start address of Flash memory.
3571 - CONFIG_SYS_MONITOR_BASE:
3572 Physical start address of boot monitor code (set by
3573 make config files to be same as the text base address
3574 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3575 CONFIG_SYS_FLASH_BASE when booting from flash.
3577 - CONFIG_SYS_MONITOR_LEN:
3578 Size of memory reserved for monitor code, used to
3579 determine _at_compile_time_ (!) if the environment is
3580 embedded within the U-Boot image, or in a separate
3583 - CONFIG_SYS_MALLOC_LEN:
3584 Size of DRAM reserved for malloc() use.
3586 - CONFIG_SYS_BOOTM_LEN:
3587 Normally compressed uImages are limited to an
3588 uncompressed size of 8 MBytes. If this is not enough,
3589 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3590 to adjust this setting to your needs.
3592 - CONFIG_SYS_BOOTMAPSZ:
3593 Maximum size of memory mapped by the startup code of
3594 the Linux kernel; all data that must be processed by
3595 the Linux kernel (bd_info, boot arguments, FDT blob if
3596 used) must be put below this limit, unless "bootm_low"
3597 environment variable is defined and non-zero. In such case
3598 all data for the Linux kernel must be between "bootm_low"
3599 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3600 variable "bootm_mapsize" will override the value of
3601 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3602 then the value in "bootm_size" will be used instead.
3604 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3605 Enable initrd_high functionality. If defined then the
3606 initrd_high feature is enabled and the bootm ramdisk subcommand
3609 - CONFIG_SYS_BOOT_GET_CMDLINE:
3610 Enables allocating and saving kernel cmdline in space between
3611 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3613 - CONFIG_SYS_BOOT_GET_KBD:
3614 Enables allocating and saving a kernel copy of the bd_info in
3615 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3617 - CONFIG_SYS_MAX_FLASH_BANKS:
3618 Max number of Flash memory banks
3620 - CONFIG_SYS_MAX_FLASH_SECT:
3621 Max number of sectors on a Flash chip
3623 - CONFIG_SYS_FLASH_ERASE_TOUT:
3624 Timeout for Flash erase operations (in ms)
3626 - CONFIG_SYS_FLASH_WRITE_TOUT:
3627 Timeout for Flash write operations (in ms)
3629 - CONFIG_SYS_FLASH_LOCK_TOUT
3630 Timeout for Flash set sector lock bit operation (in ms)
3632 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3633 Timeout for Flash clear lock bits operation (in ms)
3635 - CONFIG_SYS_FLASH_PROTECTION
3636 If defined, hardware flash sectors protection is used
3637 instead of U-Boot software protection.
3639 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3641 Enable TFTP transfers directly to flash memory;
3642 without this option such a download has to be
3643 performed in two steps: (1) download to RAM, and (2)
3644 copy from RAM to flash.
3646 The two-step approach is usually more reliable, since
3647 you can check if the download worked before you erase
3648 the flash, but in some situations (when system RAM is
3649 too limited to allow for a temporary copy of the
3650 downloaded image) this option may be very useful.
3652 - CONFIG_SYS_FLASH_CFI:
3653 Define if the flash driver uses extra elements in the
3654 common flash structure for storing flash geometry.
3656 - CONFIG_FLASH_CFI_DRIVER
3657 This option also enables the building of the cfi_flash driver
3658 in the drivers directory
3660 - CONFIG_FLASH_CFI_MTD
3661 This option enables the building of the cfi_mtd driver
3662 in the drivers directory. The driver exports CFI flash
3665 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3666 Use buffered writes to flash.
3668 - CONFIG_FLASH_SPANSION_S29WS_N
3669 s29ws-n MirrorBit flash has non-standard addresses for buffered
3672 - CONFIG_SYS_FLASH_QUIET_TEST
3673 If this option is defined, the common CFI flash doesn't
3674 print it's warning upon not recognized FLASH banks. This
3675 is useful, if some of the configured banks are only
3676 optionally available.
3678 - CONFIG_FLASH_SHOW_PROGRESS
3679 If defined (must be an integer), print out countdown
3680 digits and dots. Recommended value: 45 (9..1) for 80
3681 column displays, 15 (3..1) for 40 column displays.
3683 - CONFIG_FLASH_VERIFY
3684 If defined, the content of the flash (destination) is compared
3685 against the source after the write operation. An error message
3686 will be printed when the contents are not identical.
3687 Please note that this option is useless in nearly all cases,
3688 since such flash programming errors usually are detected earlier
3689 while unprotecting/erasing/programming. Please only enable
3690 this option if you really know what you are doing.
3692 - CONFIG_SYS_RX_ETH_BUFFER:
3693 Defines the number of Ethernet receive buffers. On some
3694 Ethernet controllers it is recommended to set this value
3695 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3696 buffers can be full shortly after enabling the interface
3697 on high Ethernet traffic.
3698 Defaults to 4 if not defined.
3700 - CONFIG_ENV_MAX_ENTRIES
3702 Maximum number of entries in the hash table that is used
3703 internally to store the environment settings. The default
3704 setting is supposed to be generous and should work in most
3705 cases. This setting can be used to tune behaviour; see
3706 lib/hashtable.c for details.
3708 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3709 - CONFIG_ENV_FLAGS_LIST_STATIC
3710 Enable validation of the values given to environment variables when
3711 calling env set. Variables can be restricted to only decimal,
3712 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3713 the variables can also be restricted to IP address or MAC address.
3715 The format of the list is:
3716 type_attribute = [s|d|x|b|i|m]
3717 access_atribute = [a|r|o|c]
3718 attributes = type_attribute[access_atribute]
3719 entry = variable_name[:attributes]
3722 The type attributes are:
3723 s - String (default)
3726 b - Boolean ([1yYtT|0nNfF])
3730 The access attributes are:
3736 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3737 Define this to a list (string) to define the ".flags"
3738 envirnoment variable in the default or embedded environment.
3740 - CONFIG_ENV_FLAGS_LIST_STATIC
3741 Define this to a list (string) to define validation that
3742 should be done if an entry is not found in the ".flags"
3743 environment variable. To override a setting in the static
3744 list, simply add an entry for the same variable name to the
3747 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3748 If defined, don't allow the -f switch to env set override variable
3751 - CONFIG_SYS_GENERIC_BOARD
3752 This selects the architecture-generic board system instead of the
3753 architecture-specific board files. It is intended to move boards
3754 to this new framework over time. Defining this will disable the
3755 arch/foo/lib/board.c file and use common/board_f.c and
3756 common/board_r.c instead. To use this option your architecture
3757 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3758 its config.mk file). If you find problems enabling this option on
3759 your board please report the problem and send patches!
3761 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3762 This is set by OMAP boards for the max time that reset should
3763 be asserted. See doc/README.omap-reset-time for details on how
3764 the value can be calulated on a given board.
3766 The following definitions that deal with the placement and management
3767 of environment data (variable area); in general, we support the
3768 following configurations:
3770 - CONFIG_BUILD_ENVCRC:
3772 Builds up envcrc with the target environment so that external utils
3773 may easily extract it and embed it in final U-Boot images.
3775 - CONFIG_ENV_IS_IN_FLASH:
3777 Define this if the environment is in flash memory.
3779 a) The environment occupies one whole flash sector, which is
3780 "embedded" in the text segment with the U-Boot code. This
3781 happens usually with "bottom boot sector" or "top boot
3782 sector" type flash chips, which have several smaller
3783 sectors at the start or the end. For instance, such a
3784 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3785 such a case you would place the environment in one of the
3786 4 kB sectors - with U-Boot code before and after it. With
3787 "top boot sector" type flash chips, you would put the
3788 environment in one of the last sectors, leaving a gap
3789 between U-Boot and the environment.
3791 - CONFIG_ENV_OFFSET:
3793 Offset of environment data (variable area) to the
3794 beginning of flash memory; for instance, with bottom boot
3795 type flash chips the second sector can be used: the offset
3796 for this sector is given here.
3798 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3802 This is just another way to specify the start address of
3803 the flash sector containing the environment (instead of
3806 - CONFIG_ENV_SECT_SIZE:
3808 Size of the sector containing the environment.
3811 b) Sometimes flash chips have few, equal sized, BIG sectors.
3812 In such a case you don't want to spend a whole sector for
3817 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3818 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3819 of this flash sector for the environment. This saves
3820 memory for the RAM copy of the environment.
3822 It may also save flash memory if you decide to use this
3823 when your environment is "embedded" within U-Boot code,
3824 since then the remainder of the flash sector could be used
3825 for U-Boot code. It should be pointed out that this is
3826 STRONGLY DISCOURAGED from a robustness point of view:
3827 updating the environment in flash makes it always
3828 necessary to erase the WHOLE sector. If something goes
3829 wrong before the contents has been restored from a copy in
3830 RAM, your target system will be dead.
3832 - CONFIG_ENV_ADDR_REDUND
3833 CONFIG_ENV_SIZE_REDUND
3835 These settings describe a second storage area used to hold
3836 a redundant copy of the environment data, so that there is
3837 a valid backup copy in case there is a power failure during
3838 a "saveenv" operation.
3840 BE CAREFUL! Any changes to the flash layout, and some changes to the
3841 source code will make it necessary to adapt <board>/u-boot.lds*
3845 - CONFIG_ENV_IS_IN_NVRAM:
3847 Define this if you have some non-volatile memory device
3848 (NVRAM, battery buffered SRAM) which you want to use for the
3854 These two #defines are used to determine the memory area you
3855 want to use for environment. It is assumed that this memory
3856 can just be read and written to, without any special
3859 BE CAREFUL! The first access to the environment happens quite early
3860 in U-Boot initalization (when we try to get the setting of for the
3861 console baudrate). You *MUST* have mapped your NVRAM area then, or
3864 Please note that even with NVRAM we still use a copy of the
3865 environment in RAM: we could work on NVRAM directly, but we want to
3866 keep settings there always unmodified except somebody uses "saveenv"
3867 to save the current settings.
3870 - CONFIG_ENV_IS_IN_EEPROM:
3872 Use this if you have an EEPROM or similar serial access
3873 device and a driver for it.
3875 - CONFIG_ENV_OFFSET:
3878 These two #defines specify the offset and size of the
3879 environment area within the total memory of your EEPROM.
3881 - CONFIG_SYS_I2C_EEPROM_ADDR:
3882 If defined, specified the chip address of the EEPROM device.
3883 The default address is zero.
3885 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3886 If defined, the number of bits used to address bytes in a
3887 single page in the EEPROM device. A 64 byte page, for example
3888 would require six bits.
3890 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3891 If defined, the number of milliseconds to delay between
3892 page writes. The default is zero milliseconds.
3894 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3895 The length in bytes of the EEPROM memory array address. Note
3896 that this is NOT the chip address length!
3898 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3899 EEPROM chips that implement "address overflow" are ones
3900 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3901 address and the extra bits end up in the "chip address" bit
3902 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3905 Note that we consider the length of the address field to
3906 still be one byte because the extra address bits are hidden
3907 in the chip address.
3909 - CONFIG_SYS_EEPROM_SIZE:
3910 The size in bytes of the EEPROM device.
3912 - CONFIG_ENV_EEPROM_IS_ON_I2C
3913 define this, if you have I2C and SPI activated, and your
3914 EEPROM, which holds the environment, is on the I2C bus.
3916 - CONFIG_I2C_ENV_EEPROM_BUS
3917 if you have an Environment on an EEPROM reached over
3918 I2C muxes, you can define here, how to reach this
3919 EEPROM. For example:
3921 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3923 EEPROM which holds the environment, is reached over
3924 a pca9547 i2c mux with address 0x70, channel 3.
3926 - CONFIG_ENV_IS_IN_DATAFLASH:
3928 Define this if you have a DataFlash memory device which you
3929 want to use for the environment.
3931 - CONFIG_ENV_OFFSET:
3935 These three #defines specify the offset and size of the
3936 environment area within the total memory of your DataFlash placed
3937 at the specified address.
3939 - CONFIG_ENV_IS_IN_REMOTE:
3941 Define this if you have a remote memory space which you
3942 want to use for the local device's environment.
3947 These two #defines specify the address and size of the
3948 environment area within the remote memory space. The
3949 local device can get the environment from remote memory
3950 space by SRIO or PCIE links.
3952 BE CAREFUL! For some special cases, the local device can not use
3953 "saveenv" command. For example, the local device will get the
3954 environment stored in a remote NOR flash by SRIO or PCIE link,
3955 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3957 - CONFIG_ENV_IS_IN_NAND:
3959 Define this if you have a NAND device which you want to use
3960 for the environment.
3962 - CONFIG_ENV_OFFSET:
3965 These two #defines specify the offset and size of the environment
3966 area within the first NAND device. CONFIG_ENV_OFFSET must be
3967 aligned to an erase block boundary.
3969 - CONFIG_ENV_OFFSET_REDUND (optional):
3971 This setting describes a second storage area of CONFIG_ENV_SIZE
3972 size used to hold a redundant copy of the environment data, so
3973 that there is a valid backup copy in case there is a power failure
3974 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3975 aligned to an erase block boundary.
3977 - CONFIG_ENV_RANGE (optional):
3979 Specifies the length of the region in which the environment
3980 can be written. This should be a multiple of the NAND device's
3981 block size. Specifying a range with more erase blocks than
3982 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3983 the range to be avoided.
3985 - CONFIG_ENV_OFFSET_OOB (optional):
3987 Enables support for dynamically retrieving the offset of the
3988 environment from block zero's out-of-band data. The
3989 "nand env.oob" command can be used to record this offset.
3990 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3991 using CONFIG_ENV_OFFSET_OOB.
3993 - CONFIG_NAND_ENV_DST
3995 Defines address in RAM to which the nand_spl code should copy the
3996 environment. If redundant environment is used, it will be copied to
3997 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3999 - CONFIG_ENV_IS_IN_UBI:
4001 Define this if you have an UBI volume that you want to use for the
4002 environment. This has the benefit of wear-leveling the environment
4003 accesses, which is important on NAND.
4005 - CONFIG_ENV_UBI_PART:
4007 Define this to a string that is the mtd partition containing the UBI.
4009 - CONFIG_ENV_UBI_VOLUME:
4011 Define this to the name of the volume that you want to store the
4014 - CONFIG_ENV_UBI_VOLUME_REDUND:
4016 Define this to the name of another volume to store a second copy of
4017 the environment in. This will enable redundant environments in UBI.
4018 It is assumed that both volumes are in the same MTD partition.
4020 - CONFIG_UBI_SILENCE_MSG
4021 - CONFIG_UBIFS_SILENCE_MSG
4023 You will probably want to define these to avoid a really noisy system
4024 when storing the env in UBI.
4026 - CONFIG_ENV_IS_IN_MMC:
4028 Define this if you have an MMC device which you want to use for the
4031 - CONFIG_SYS_MMC_ENV_DEV:
4033 Specifies which MMC device the environment is stored in.
4035 - CONFIG_SYS_MMC_ENV_PART (optional):
4037 Specifies which MMC partition the environment is stored in. If not
4038 set, defaults to partition 0, the user area. Common values might be
4039 1 (first MMC boot partition), 2 (second MMC boot partition).
4041 - CONFIG_ENV_OFFSET:
4044 These two #defines specify the offset and size of the environment
4045 area within the specified MMC device.
4047 If offset is positive (the usual case), it is treated as relative to
4048 the start of the MMC partition. If offset is negative, it is treated
4049 as relative to the end of the MMC partition. This can be useful if
4050 your board may be fitted with different MMC devices, which have
4051 different sizes for the MMC partitions, and you always want the
4052 environment placed at the very end of the partition, to leave the
4053 maximum possible space before it, to store other data.
4055 These two values are in units of bytes, but must be aligned to an
4056 MMC sector boundary.
4058 - CONFIG_ENV_OFFSET_REDUND (optional):
4060 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4061 hold a redundant copy of the environment data. This provides a
4062 valid backup copy in case the other copy is corrupted, e.g. due
4063 to a power failure during a "saveenv" operation.
4065 This value may also be positive or negative; this is handled in the
4066 same way as CONFIG_ENV_OFFSET.
4068 This value is also in units of bytes, but must also be aligned to
4069 an MMC sector boundary.
4071 - CONFIG_ENV_SIZE_REDUND (optional):
4073 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4074 set. If this value is set, it must be set to the same value as
4077 - CONFIG_SYS_SPI_INIT_OFFSET
4079 Defines offset to the initial SPI buffer area in DPRAM. The
4080 area is used at an early stage (ROM part) if the environment
4081 is configured to reside in the SPI EEPROM: We need a 520 byte
4082 scratch DPRAM area. It is used between the two initialization
4083 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4084 to be a good choice since it makes it far enough from the
4085 start of the data area as well as from the stack pointer.
4087 Please note that the environment is read-only until the monitor
4088 has been relocated to RAM and a RAM copy of the environment has been
4089 created; also, when using EEPROM you will have to use getenv_f()
4090 until then to read environment variables.
4092 The environment is protected by a CRC32 checksum. Before the monitor
4093 is relocated into RAM, as a result of a bad CRC you will be working
4094 with the compiled-in default environment - *silently*!!! [This is
4095 necessary, because the first environment variable we need is the
4096 "baudrate" setting for the console - if we have a bad CRC, we don't
4097 have any device yet where we could complain.]
4099 Note: once the monitor has been relocated, then it will complain if
4100 the default environment is used; a new CRC is computed as soon as you
4101 use the "saveenv" command to store a valid environment.
4103 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4104 Echo the inverted Ethernet link state to the fault LED.
4106 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4107 also needs to be defined.
4109 - CONFIG_SYS_FAULT_MII_ADDR:
4110 MII address of the PHY to check for the Ethernet link state.
4112 - CONFIG_NS16550_MIN_FUNCTIONS:
4113 Define this if you desire to only have use of the NS16550_init
4114 and NS16550_putc functions for the serial driver located at
4115 drivers/serial/ns16550.c. This option is useful for saving
4116 space for already greatly restricted images, including but not
4117 limited to NAND_SPL configurations.
4119 - CONFIG_DISPLAY_BOARDINFO
4120 Display information about the board that U-Boot is running on
4121 when U-Boot starts up. The board function checkboard() is called
4124 - CONFIG_DISPLAY_BOARDINFO_LATE
4125 Similar to the previous option, but display this information
4126 later, once stdio is running and output goes to the LCD, if
4129 Low Level (hardware related) configuration options:
4130 ---------------------------------------------------
4132 - CONFIG_SYS_CACHELINE_SIZE:
4133 Cache Line Size of the CPU.
4135 - CONFIG_SYS_DEFAULT_IMMR:
4136 Default address of the IMMR after system reset.
4138 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4139 and RPXsuper) to be able to adjust the position of
4140 the IMMR register after a reset.
4142 - CONFIG_SYS_CCSRBAR_DEFAULT:
4143 Default (power-on reset) physical address of CCSR on Freescale
4146 - CONFIG_SYS_CCSRBAR:
4147 Virtual address of CCSR. On a 32-bit build, this is typically
4148 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4150 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4151 for cross-platform code that uses that macro instead.
4153 - CONFIG_SYS_CCSRBAR_PHYS:
4154 Physical address of CCSR. CCSR can be relocated to a new
4155 physical address, if desired. In this case, this macro should
4156 be set to that address. Otherwise, it should be set to the
4157 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4158 is typically relocated on 36-bit builds. It is recommended
4159 that this macro be defined via the _HIGH and _LOW macros:
4161 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4162 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4164 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4165 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4166 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4167 used in assembly code, so it must not contain typecasts or
4168 integer size suffixes (e.g. "ULL").
4170 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4171 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4172 used in assembly code, so it must not contain typecasts or
4173 integer size suffixes (e.g. "ULL").
4175 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4176 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4177 forced to a value that ensures that CCSR is not relocated.
4179 - Floppy Disk Support:
4180 CONFIG_SYS_FDC_DRIVE_NUMBER
4182 the default drive number (default value 0)
4184 CONFIG_SYS_ISA_IO_STRIDE
4186 defines the spacing between FDC chipset registers
4189 CONFIG_SYS_ISA_IO_OFFSET
4191 defines the offset of register from address. It
4192 depends on which part of the data bus is connected to
4193 the FDC chipset. (default value 0)
4195 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4196 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4199 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4200 fdc_hw_init() is called at the beginning of the FDC
4201 setup. fdc_hw_init() must be provided by the board
4202 source code. It is used to make hardware dependant
4206 Most IDE controllers were designed to be connected with PCI
4207 interface. Only few of them were designed for AHB interface.
4208 When software is doing ATA command and data transfer to
4209 IDE devices through IDE-AHB controller, some additional
4210 registers accessing to these kind of IDE-AHB controller
4213 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4214 DO NOT CHANGE unless you know exactly what you're
4215 doing! (11-4) [MPC8xx/82xx systems only]
4217 - CONFIG_SYS_INIT_RAM_ADDR:
4219 Start address of memory area that can be used for
4220 initial data and stack; please note that this must be
4221 writable memory that is working WITHOUT special
4222 initialization, i. e. you CANNOT use normal RAM which
4223 will become available only after programming the
4224 memory controller and running certain initialization
4227 U-Boot uses the following memory types:
4228 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4229 - MPC824X: data cache
4230 - PPC4xx: data cache
4232 - CONFIG_SYS_GBL_DATA_OFFSET:
4234 Offset of the initial data structure in the memory
4235 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4236 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4237 data is located at the end of the available space
4238 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4239 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4240 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4241 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4244 On the MPC824X (or other systems that use the data
4245 cache for initial memory) the address chosen for
4246 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4247 point to an otherwise UNUSED address space between
4248 the top of RAM and the start of the PCI space.
4250 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4252 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4254 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4256 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4258 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4260 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4262 - CONFIG_SYS_OR_TIMING_SDRAM:
4265 - CONFIG_SYS_MAMR_PTA:
4266 periodic timer for refresh
4268 - CONFIG_SYS_DER: Debug Event Register (37-47)
4270 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4271 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4272 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4273 CONFIG_SYS_BR1_PRELIM:
4274 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4276 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4277 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4278 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4279 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4281 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4282 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4283 Machine Mode Register and Memory Periodic Timer
4284 Prescaler definitions (SDRAM timing)
4286 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4287 enable I2C microcode relocation patch (MPC8xx);
4288 define relocation offset in DPRAM [DSP2]
4290 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4291 enable SMC microcode relocation patch (MPC8xx);
4292 define relocation offset in DPRAM [SMC1]
4294 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4295 enable SPI microcode relocation patch (MPC8xx);
4296 define relocation offset in DPRAM [SCC4]
4298 - CONFIG_SYS_USE_OSCCLK:
4299 Use OSCM clock mode on MBX8xx board. Be careful,
4300 wrong setting might damage your board. Read
4301 doc/README.MBX before setting this variable!
4303 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4304 Offset of the bootmode word in DPRAM used by post
4305 (Power On Self Tests). This definition overrides
4306 #define'd default value in commproc.h resp.
4309 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4310 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4311 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4312 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4313 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4314 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4315 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4316 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4317 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4319 - CONFIG_PCI_DISABLE_PCIE:
4320 Disable PCI-Express on systems where it is supported but not
4323 - CONFIG_PCI_ENUM_ONLY
4324 Only scan through and get the devices on the busses.
4325 Don't do any setup work, presumably because someone or
4326 something has already done it, and we don't need to do it
4327 a second time. Useful for platforms that are pre-booted
4328 by coreboot or similar.
4330 - CONFIG_PCI_INDIRECT_BRIDGE:
4331 Enable support for indirect PCI bridges.
4334 Chip has SRIO or not
4337 Board has SRIO 1 port available
4340 Board has SRIO 2 port available
4342 - CONFIG_SRIO_PCIE_BOOT_MASTER
4343 Board can support master function for Boot from SRIO and PCIE
4345 - CONFIG_SYS_SRIOn_MEM_VIRT:
4346 Virtual Address of SRIO port 'n' memory region
4348 - CONFIG_SYS_SRIOn_MEM_PHYS:
4349 Physical Address of SRIO port 'n' memory region
4351 - CONFIG_SYS_SRIOn_MEM_SIZE:
4352 Size of SRIO port 'n' memory region
4354 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4355 Defined to tell the NAND controller that the NAND chip is using
4357 Not all NAND drivers use this symbol.
4358 Example of drivers that use it:
4359 - drivers/mtd/nand/ndfc.c
4360 - drivers/mtd/nand/mxc_nand.c
4362 - CONFIG_SYS_NDFC_EBC0_CFG
4363 Sets the EBC0_CFG register for the NDFC. If not defined
4364 a default value will be used.
4367 Get DDR timing information from an I2C EEPROM. Common
4368 with pluggable memory modules such as SODIMMs
4371 I2C address of the SPD EEPROM
4373 - CONFIG_SYS_SPD_BUS_NUM
4374 If SPD EEPROM is on an I2C bus other than the first
4375 one, specify here. Note that the value must resolve
4376 to something your driver can deal with.
4378 - CONFIG_SYS_DDR_RAW_TIMING
4379 Get DDR timing information from other than SPD. Common with
4380 soldered DDR chips onboard without SPD. DDR raw timing
4381 parameters are extracted from datasheet and hard-coded into
4382 header files or board specific files.
4384 - CONFIG_FSL_DDR_INTERACTIVE
4385 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4387 - CONFIG_SYS_83XX_DDR_USES_CS0
4388 Only for 83xx systems. If specified, then DDR should
4389 be configured using CS0 and CS1 instead of CS2 and CS3.
4391 - CONFIG_ETHER_ON_FEC[12]
4392 Define to enable FEC[12] on a 8xx series processor.
4394 - CONFIG_FEC[12]_PHY
4395 Define to the hardcoded PHY address which corresponds
4396 to the given FEC; i. e.
4397 #define CONFIG_FEC1_PHY 4
4398 means that the PHY with address 4 is connected to FEC1
4400 When set to -1, means to probe for first available.
4402 - CONFIG_FEC[12]_PHY_NORXERR
4403 The PHY does not have a RXERR line (RMII only).
4404 (so program the FEC to ignore it).
4407 Enable RMII mode for all FECs.
4408 Note that this is a global option, we can't
4409 have one FEC in standard MII mode and another in RMII mode.
4411 - CONFIG_CRC32_VERIFY
4412 Add a verify option to the crc32 command.
4415 => crc32 -v <address> <count> <crc32>
4417 Where address/count indicate a memory area
4418 and crc32 is the correct crc32 which the
4422 Add the "loopw" memory command. This only takes effect if
4423 the memory commands are activated globally (CONFIG_CMD_MEM).
4426 Add the "mdc" and "mwc" memory commands. These are cyclic
4431 This command will print 4 bytes (10,11,12,13) each 500 ms.
4433 => mwc.l 100 12345678 10
4434 This command will write 12345678 to address 100 all 10 ms.
4436 This only takes effect if the memory commands are activated
4437 globally (CONFIG_CMD_MEM).
4439 - CONFIG_SKIP_LOWLEVEL_INIT
4440 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4441 low level initializations (like setting up the memory
4442 controller) are omitted and/or U-Boot does not
4443 relocate itself into RAM.
4445 Normally this variable MUST NOT be defined. The only
4446 exception is when U-Boot is loaded (to RAM) by some
4447 other boot loader or by a debugger which performs
4448 these initializations itself.
4451 Modifies the behaviour of start.S when compiling a loader
4452 that is executed before the actual U-Boot. E.g. when
4453 compiling a NAND SPL.
4456 Modifies the behaviour of start.S when compiling a loader
4457 that is executed after the SPL and before the actual U-Boot.
4458 It is loaded by the SPL.
4460 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4461 Only for 85xx systems. If this variable is specified, the section
4462 .resetvec is not kept and the section .bootpg is placed in the
4463 previous 4k of the .text section.
4465 - CONFIG_ARCH_MAP_SYSMEM
4466 Generally U-Boot (and in particular the md command) uses
4467 effective address. It is therefore not necessary to regard
4468 U-Boot address as virtual addresses that need to be translated
4469 to physical addresses. However, sandbox requires this, since
4470 it maintains its own little RAM buffer which contains all
4471 addressable memory. This option causes some memory accesses
4472 to be mapped through map_sysmem() / unmap_sysmem().
4474 - CONFIG_USE_ARCH_MEMCPY
4475 CONFIG_USE_ARCH_MEMSET
4476 If these options are used a optimized version of memcpy/memset will
4477 be used if available. These functions may be faster under some
4478 conditions but may increase the binary size.
4480 - CONFIG_X86_RESET_VECTOR
4481 If defined, the x86 reset vector code is included. This is not
4482 needed when U-Boot is running from Coreboot.
4485 Defines the MPU clock speed (in MHz).
4487 NOTE : currently only supported on AM335x platforms.
4489 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4490 Enables the RTC32K OSC on AM33xx based plattforms
4492 Freescale QE/FMAN Firmware Support:
4493 -----------------------------------
4495 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4496 loading of "firmware", which is encoded in the QE firmware binary format.
4497 This firmware often needs to be loaded during U-Boot booting, so macros
4498 are used to identify the storage device (NOR flash, SPI, etc) and the address
4501 - CONFIG_SYS_QE_FMAN_FW_ADDR
4502 The address in the storage device where the firmware is located. The
4503 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4506 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4507 The maximum possible size of the firmware. The firmware binary format
4508 has a field that specifies the actual size of the firmware, but it
4509 might not be possible to read any part of the firmware unless some
4510 local storage is allocated to hold the entire firmware first.
4512 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4513 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4514 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4515 virtual address in NOR flash.
4517 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4518 Specifies that QE/FMAN firmware is located in NAND flash.
4519 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4521 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4522 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4523 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4525 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4526 Specifies that QE/FMAN firmware is located on the primary SPI
4527 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4529 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4530 Specifies that QE/FMAN firmware is located in the remote (master)
4531 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4532 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4533 window->master inbound window->master LAW->the ucode address in
4534 master's memory space.
4536 Building the Software:
4537 ======================
4539 Building U-Boot has been tested in several native build environments
4540 and in many different cross environments. Of course we cannot support
4541 all possibly existing versions of cross development tools in all
4542 (potentially obsolete) versions. In case of tool chain problems we
4543 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4544 which is extensively used to build and test U-Boot.
4546 If you are not using a native environment, it is assumed that you
4547 have GNU cross compiling tools available in your path. In this case,
4548 you must set the environment variable CROSS_COMPILE in your shell.
4549 Note that no changes to the Makefile or any other source files are
4550 necessary. For example using the ELDK on a 4xx CPU, please enter:
4552 $ CROSS_COMPILE=ppc_4xx-
4553 $ export CROSS_COMPILE
4555 Note: If you wish to generate Windows versions of the utilities in
4556 the tools directory you can use the MinGW toolchain
4557 (http://www.mingw.org). Set your HOST tools to the MinGW
4558 toolchain and execute 'make tools'. For example:
4560 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4562 Binaries such as tools/mkimage.exe will be created which can
4563 be executed on computers running Windows.
4565 U-Boot is intended to be simple to build. After installing the
4566 sources you must configure U-Boot for one specific board type. This
4571 where "NAME_config" is the name of one of the existing configu-
4572 rations; see boards.cfg for supported names.
4574 Note: for some board special configuration names may exist; check if
4575 additional information is available from the board vendor; for
4576 instance, the TQM823L systems are available without (standard)
4577 or with LCD support. You can select such additional "features"
4578 when choosing the configuration, i. e.
4581 - will configure for a plain TQM823L, i. e. no LCD support
4583 make TQM823L_LCD_config
4584 - will configure for a TQM823L with U-Boot console on LCD
4589 Finally, type "make all", and you should get some working U-Boot
4590 images ready for download to / installation on your system:
4592 - "u-boot.bin" is a raw binary image
4593 - "u-boot" is an image in ELF binary format
4594 - "u-boot.srec" is in Motorola S-Record format
4596 By default the build is performed locally and the objects are saved
4597 in the source directory. One of the two methods can be used to change
4598 this behavior and build U-Boot to some external directory:
4600 1. Add O= to the make command line invocations:
4602 make O=/tmp/build distclean
4603 make O=/tmp/build NAME_config
4604 make O=/tmp/build all
4606 2. Set environment variable BUILD_DIR to point to the desired location:
4608 export BUILD_DIR=/tmp/build
4613 Note that the command line "O=" setting overrides the BUILD_DIR environment
4617 Please be aware that the Makefiles assume you are using GNU make, so
4618 for instance on NetBSD you might need to use "gmake" instead of
4622 If the system board that you have is not listed, then you will need
4623 to port U-Boot to your hardware platform. To do this, follow these
4626 1. Add a new configuration option for your board to the toplevel
4627 "boards.cfg" file, using the existing entries as examples.
4628 Follow the instructions there to keep the boards in order.
4629 2. Create a new directory to hold your board specific code. Add any
4630 files you need. In your board directory, you will need at least
4631 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4632 3. Create a new configuration file "include/configs/<board>.h" for
4634 3. If you're porting U-Boot to a new CPU, then also create a new
4635 directory to hold your CPU specific code. Add any files you need.
4636 4. Run "make <board>_config" with your new name.
4637 5. Type "make", and you should get a working "u-boot.srec" file
4638 to be installed on your target system.
4639 6. Debug and solve any problems that might arise.
4640 [Of course, this last step is much harder than it sounds.]
4643 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4644 ==============================================================
4646 If you have modified U-Boot sources (for instance added a new board
4647 or support for new devices, a new CPU, etc.) you are expected to
4648 provide feedback to the other developers. The feedback normally takes
4649 the form of a "patch", i. e. a context diff against a certain (latest
4650 official or latest in the git repository) version of U-Boot sources.
4652 But before you submit such a patch, please verify that your modifi-
4653 cation did not break existing code. At least make sure that *ALL* of
4654 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4655 just run the "MAKEALL" script, which will configure and build U-Boot
4656 for ALL supported system. Be warned, this will take a while. You can
4657 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4658 environment variable to the script, i. e. to use the ELDK cross tools
4661 CROSS_COMPILE=ppc_8xx- MAKEALL
4663 or to build on a native PowerPC system you can type
4665 CROSS_COMPILE=' ' MAKEALL
4667 When using the MAKEALL script, the default behaviour is to build
4668 U-Boot in the source directory. This location can be changed by
4669 setting the BUILD_DIR environment variable. Also, for each target
4670 built, the MAKEALL script saves two log files (<target>.ERR and
4671 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4672 location can be changed by setting the MAKEALL_LOGDIR environment
4673 variable. For example:
4675 export BUILD_DIR=/tmp/build
4676 export MAKEALL_LOGDIR=/tmp/log
4677 CROSS_COMPILE=ppc_8xx- MAKEALL
4679 With the above settings build objects are saved in the /tmp/build,
4680 log files are saved in the /tmp/log and the source tree remains clean
4681 during the whole build process.
4684 See also "U-Boot Porting Guide" below.
4687 Monitor Commands - Overview:
4688 ============================
4690 go - start application at address 'addr'
4691 run - run commands in an environment variable
4692 bootm - boot application image from memory
4693 bootp - boot image via network using BootP/TFTP protocol
4694 bootz - boot zImage from memory
4695 tftpboot- boot image via network using TFTP protocol
4696 and env variables "ipaddr" and "serverip"
4697 (and eventually "gatewayip")
4698 tftpput - upload a file via network using TFTP protocol
4699 rarpboot- boot image via network using RARP/TFTP protocol
4700 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4701 loads - load S-Record file over serial line
4702 loadb - load binary file over serial line (kermit mode)
4704 mm - memory modify (auto-incrementing)
4705 nm - memory modify (constant address)
4706 mw - memory write (fill)
4708 cmp - memory compare
4709 crc32 - checksum calculation
4710 i2c - I2C sub-system
4711 sspi - SPI utility commands
4712 base - print or set address offset
4713 printenv- print environment variables
4714 setenv - set environment variables
4715 saveenv - save environment variables to persistent storage
4716 protect - enable or disable FLASH write protection
4717 erase - erase FLASH memory
4718 flinfo - print FLASH memory information
4719 nand - NAND memory operations (see doc/README.nand)
4720 bdinfo - print Board Info structure
4721 iminfo - print header information for application image
4722 coninfo - print console devices and informations
4723 ide - IDE sub-system
4724 loop - infinite loop on address range
4725 loopw - infinite write loop on address range
4726 mtest - simple RAM test
4727 icache - enable or disable instruction cache
4728 dcache - enable or disable data cache
4729 reset - Perform RESET of the CPU
4730 echo - echo args to console
4731 version - print monitor version
4732 help - print online help
4733 ? - alias for 'help'
4736 Monitor Commands - Detailed Description:
4737 ========================================
4741 For now: just type "help <command>".
4744 Environment Variables:
4745 ======================
4747 U-Boot supports user configuration using Environment Variables which
4748 can be made persistent by saving to Flash memory.
4750 Environment Variables are set using "setenv", printed using
4751 "printenv", and saved to Flash using "saveenv". Using "setenv"
4752 without a value can be used to delete a variable from the
4753 environment. As long as you don't save the environment you are
4754 working with an in-memory copy. In case the Flash area containing the
4755 environment is erased by accident, a default environment is provided.
4757 Some configuration options can be set using Environment Variables.
4759 List of environment variables (most likely not complete):
4761 baudrate - see CONFIG_BAUDRATE
4763 bootdelay - see CONFIG_BOOTDELAY
4765 bootcmd - see CONFIG_BOOTCOMMAND
4767 bootargs - Boot arguments when booting an RTOS image
4769 bootfile - Name of the image to load with TFTP
4771 bootm_low - Memory range available for image processing in the bootm
4772 command can be restricted. This variable is given as
4773 a hexadecimal number and defines lowest address allowed
4774 for use by the bootm command. See also "bootm_size"
4775 environment variable. Address defined by "bootm_low" is
4776 also the base of the initial memory mapping for the Linux
4777 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4780 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4781 This variable is given as a hexadecimal number and it
4782 defines the size of the memory region starting at base
4783 address bootm_low that is accessible by the Linux kernel
4784 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4785 as the default value if it is defined, and bootm_size is
4788 bootm_size - Memory range available for image processing in the bootm
4789 command can be restricted. This variable is given as
4790 a hexadecimal number and defines the size of the region
4791 allowed for use by the bootm command. See also "bootm_low"
4792 environment variable.
4794 updatefile - Location of the software update file on a TFTP server, used
4795 by the automatic software update feature. Please refer to
4796 documentation in doc/README.update for more details.
4798 autoload - if set to "no" (any string beginning with 'n'),
4799 "bootp" will just load perform a lookup of the
4800 configuration from the BOOTP server, but not try to
4801 load any image using TFTP
4803 autostart - if set to "yes", an image loaded using the "bootp",
4804 "rarpboot", "tftpboot" or "diskboot" commands will
4805 be automatically started (by internally calling
4808 If set to "no", a standalone image passed to the
4809 "bootm" command will be copied to the load address
4810 (and eventually uncompressed), but NOT be started.
4811 This can be used to load and uncompress arbitrary
4814 fdt_high - if set this restricts the maximum address that the
4815 flattened device tree will be copied into upon boot.
4816 For example, if you have a system with 1 GB memory
4817 at physical address 0x10000000, while Linux kernel
4818 only recognizes the first 704 MB as low memory, you
4819 may need to set fdt_high as 0x3C000000 to have the
4820 device tree blob be copied to the maximum address
4821 of the 704 MB low memory, so that Linux kernel can
4822 access it during the boot procedure.
4824 If this is set to the special value 0xFFFFFFFF then
4825 the fdt will not be copied at all on boot. For this
4826 to work it must reside in writable memory, have
4827 sufficient padding on the end of it for u-boot to
4828 add the information it needs into it, and the memory
4829 must be accessible by the kernel.
4831 fdtcontroladdr- if set this is the address of the control flattened
4832 device tree used by U-Boot when CONFIG_OF_CONTROL is
4835 i2cfast - (PPC405GP|PPC405EP only)
4836 if set to 'y' configures Linux I2C driver for fast
4837 mode (400kHZ). This environment variable is used in
4838 initialization code. So, for changes to be effective
4839 it must be saved and board must be reset.
4841 initrd_high - restrict positioning of initrd images:
4842 If this variable is not set, initrd images will be
4843 copied to the highest possible address in RAM; this
4844 is usually what you want since it allows for
4845 maximum initrd size. If for some reason you want to
4846 make sure that the initrd image is loaded below the
4847 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4848 variable to a value of "no" or "off" or "0".
4849 Alternatively, you can set it to a maximum upper
4850 address to use (U-Boot will still check that it
4851 does not overwrite the U-Boot stack and data).
4853 For instance, when you have a system with 16 MB
4854 RAM, and want to reserve 4 MB from use by Linux,
4855 you can do this by adding "mem=12M" to the value of
4856 the "bootargs" variable. However, now you must make
4857 sure that the initrd image is placed in the first
4858 12 MB as well - this can be done with
4860 setenv initrd_high 00c00000
4862 If you set initrd_high to 0xFFFFFFFF, this is an
4863 indication to U-Boot that all addresses are legal
4864 for the Linux kernel, including addresses in flash
4865 memory. In this case U-Boot will NOT COPY the
4866 ramdisk at all. This may be useful to reduce the
4867 boot time on your system, but requires that this
4868 feature is supported by your Linux kernel.
4870 ipaddr - IP address; needed for tftpboot command
4872 loadaddr - Default load address for commands like "bootp",
4873 "rarpboot", "tftpboot", "loadb" or "diskboot"
4875 loads_echo - see CONFIG_LOADS_ECHO
4877 serverip - TFTP server IP address; needed for tftpboot command
4879 bootretry - see CONFIG_BOOT_RETRY_TIME
4881 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4883 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4885 ethprime - controls which interface is used first.
4887 ethact - controls which interface is currently active.
4888 For example you can do the following
4890 => setenv ethact FEC
4891 => ping 192.168.0.1 # traffic sent on FEC
4892 => setenv ethact SCC
4893 => ping 10.0.0.1 # traffic sent on SCC
4895 ethrotate - When set to "no" U-Boot does not go through all
4896 available network interfaces.
4897 It just stays at the currently selected interface.
4899 netretry - When set to "no" each network operation will
4900 either succeed or fail without retrying.
4901 When set to "once" the network operation will
4902 fail when all the available network interfaces
4903 are tried once without success.
4904 Useful on scripts which control the retry operation
4907 npe_ucode - set load address for the NPE microcode
4909 silent_linux - If set then linux will be told to boot silently, by
4910 changing the console to be empty. If "yes" it will be
4911 made silent. If "no" it will not be made silent. If
4912 unset, then it will be made silent if the U-Boot console
4915 tftpsrcport - If this is set, the value is used for TFTP's
4918 tftpdstport - If this is set, the value is used for TFTP's UDP
4919 destination port instead of the Well Know Port 69.
4921 tftpblocksize - Block size to use for TFTP transfers; if not set,
4922 we use the TFTP server's default block size
4924 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4925 seconds, minimum value is 1000 = 1 second). Defines
4926 when a packet is considered to be lost so it has to
4927 be retransmitted. The default is 5000 = 5 seconds.
4928 Lowering this value may make downloads succeed
4929 faster in networks with high packet loss rates or
4930 with unreliable TFTP servers.
4932 vlan - When set to a value < 4095 the traffic over
4933 Ethernet is encapsulated/received over 802.1q
4936 The following image location variables contain the location of images
4937 used in booting. The "Image" column gives the role of the image and is
4938 not an environment variable name. The other columns are environment
4939 variable names. "File Name" gives the name of the file on a TFTP
4940 server, "RAM Address" gives the location in RAM the image will be
4941 loaded to, and "Flash Location" gives the image's address in NOR
4942 flash or offset in NAND flash.
4944 *Note* - these variables don't have to be defined for all boards, some
4945 boards currenlty use other variables for these purposes, and some
4946 boards use these variables for other purposes.
4948 Image File Name RAM Address Flash Location
4949 ----- --------- ----------- --------------
4950 u-boot u-boot u-boot_addr_r u-boot_addr
4951 Linux kernel bootfile kernel_addr_r kernel_addr
4952 device tree blob fdtfile fdt_addr_r fdt_addr
4953 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4955 The following environment variables may be used and automatically
4956 updated by the network boot commands ("bootp" and "rarpboot"),
4957 depending the information provided by your boot server:
4959 bootfile - see above
4960 dnsip - IP address of your Domain Name Server
4961 dnsip2 - IP address of your secondary Domain Name Server
4962 gatewayip - IP address of the Gateway (Router) to use
4963 hostname - Target hostname
4965 netmask - Subnet Mask
4966 rootpath - Pathname of the root filesystem on the NFS server
4967 serverip - see above
4970 There are two special Environment Variables:
4972 serial# - contains hardware identification information such
4973 as type string and/or serial number
4974 ethaddr - Ethernet address
4976 These variables can be set only once (usually during manufacturing of
4977 the board). U-Boot refuses to delete or overwrite these variables
4978 once they have been set once.
4981 Further special Environment Variables:
4983 ver - Contains the U-Boot version string as printed
4984 with the "version" command. This variable is
4985 readonly (see CONFIG_VERSION_VARIABLE).
4988 Please note that changes to some configuration parameters may take
4989 only effect after the next boot (yes, that's just like Windoze :-).
4992 Callback functions for environment variables:
4993 ---------------------------------------------
4995 For some environment variables, the behavior of u-boot needs to change
4996 when their values are changed. This functionailty allows functions to
4997 be associated with arbitrary variables. On creation, overwrite, or
4998 deletion, the callback will provide the opportunity for some side
4999 effect to happen or for the change to be rejected.
5001 The callbacks are named and associated with a function using the
5002 U_BOOT_ENV_CALLBACK macro in your board or driver code.
5004 These callbacks are associated with variables in one of two ways. The
5005 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
5006 in the board configuration to a string that defines a list of
5007 associations. The list must be in the following format:
5009 entry = variable_name[:callback_name]
5012 If the callback name is not specified, then the callback is deleted.
5013 Spaces are also allowed anywhere in the list.
5015 Callbacks can also be associated by defining the ".callbacks" variable
5016 with the same list format above. Any association in ".callbacks" will
5017 override any association in the static list. You can define
5018 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5019 ".callbacks" envirnoment variable in the default or embedded environment.
5022 Command Line Parsing:
5023 =====================
5025 There are two different command line parsers available with U-Boot:
5026 the old "simple" one, and the much more powerful "hush" shell:
5028 Old, simple command line parser:
5029 --------------------------------
5031 - supports environment variables (through setenv / saveenv commands)
5032 - several commands on one line, separated by ';'
5033 - variable substitution using "... ${name} ..." syntax
5034 - special characters ('$', ';') can be escaped by prefixing with '\',
5036 setenv bootcmd bootm \${address}
5037 - You can also escape text by enclosing in single apostrophes, for example:
5038 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5043 - similar to Bourne shell, with control structures like
5044 if...then...else...fi, for...do...done; while...do...done,
5045 until...do...done, ...
5046 - supports environment ("global") variables (through setenv / saveenv
5047 commands) and local shell variables (through standard shell syntax
5048 "name=value"); only environment variables can be used with "run"
5054 (1) If a command line (or an environment variable executed by a "run"
5055 command) contains several commands separated by semicolon, and
5056 one of these commands fails, then the remaining commands will be
5059 (2) If you execute several variables with one call to run (i. e.
5060 calling run with a list of variables as arguments), any failing
5061 command will cause "run" to terminate, i. e. the remaining
5062 variables are not executed.
5064 Note for Redundant Ethernet Interfaces:
5065 =======================================
5067 Some boards come with redundant Ethernet interfaces; U-Boot supports
5068 such configurations and is capable of automatic selection of a
5069 "working" interface when needed. MAC assignment works as follows:
5071 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5072 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5073 "eth1addr" (=>eth1), "eth2addr", ...
5075 If the network interface stores some valid MAC address (for instance
5076 in SROM), this is used as default address if there is NO correspon-
5077 ding setting in the environment; if the corresponding environment
5078 variable is set, this overrides the settings in the card; that means:
5080 o If the SROM has a valid MAC address, and there is no address in the
5081 environment, the SROM's address is used.
5083 o If there is no valid address in the SROM, and a definition in the
5084 environment exists, then the value from the environment variable is
5087 o If both the SROM and the environment contain a MAC address, and
5088 both addresses are the same, this MAC address is used.
5090 o If both the SROM and the environment contain a MAC address, and the
5091 addresses differ, the value from the environment is used and a
5094 o If neither SROM nor the environment contain a MAC address, an error
5097 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5098 will be programmed into hardware as part of the initialization process. This
5099 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5100 The naming convention is as follows:
5101 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5106 U-Boot is capable of booting (and performing other auxiliary operations on)
5107 images in two formats:
5109 New uImage format (FIT)
5110 -----------------------
5112 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5113 to Flattened Device Tree). It allows the use of images with multiple
5114 components (several kernels, ramdisks, etc.), with contents protected by
5115 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5121 Old image format is based on binary files which can be basically anything,
5122 preceded by a special header; see the definitions in include/image.h for
5123 details; basically, the header defines the following image properties:
5125 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5126 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5127 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5128 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5130 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5131 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5132 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5133 * Compression Type (uncompressed, gzip, bzip2)
5139 The header is marked by a special Magic Number, and both the header
5140 and the data portions of the image are secured against corruption by
5147 Although U-Boot should support any OS or standalone application
5148 easily, the main focus has always been on Linux during the design of
5151 U-Boot includes many features that so far have been part of some
5152 special "boot loader" code within the Linux kernel. Also, any
5153 "initrd" images to be used are no longer part of one big Linux image;
5154 instead, kernel and "initrd" are separate images. This implementation
5155 serves several purposes:
5157 - the same features can be used for other OS or standalone
5158 applications (for instance: using compressed images to reduce the
5159 Flash memory footprint)
5161 - it becomes much easier to port new Linux kernel versions because
5162 lots of low-level, hardware dependent stuff are done by U-Boot
5164 - the same Linux kernel image can now be used with different "initrd"
5165 images; of course this also means that different kernel images can
5166 be run with the same "initrd". This makes testing easier (you don't
5167 have to build a new "zImage.initrd" Linux image when you just
5168 change a file in your "initrd"). Also, a field-upgrade of the
5169 software is easier now.
5175 Porting Linux to U-Boot based systems:
5176 ---------------------------------------
5178 U-Boot cannot save you from doing all the necessary modifications to
5179 configure the Linux device drivers for use with your target hardware
5180 (no, we don't intend to provide a full virtual machine interface to
5183 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5185 Just make sure your machine specific header file (for instance
5186 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5187 Information structure as we define in include/asm-<arch>/u-boot.h,
5188 and make sure that your definition of IMAP_ADDR uses the same value
5189 as your U-Boot configuration in CONFIG_SYS_IMMR.
5192 Configuring the Linux kernel:
5193 -----------------------------
5195 No specific requirements for U-Boot. Make sure you have some root
5196 device (initial ramdisk, NFS) for your target system.
5199 Building a Linux Image:
5200 -----------------------
5202 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5203 not used. If you use recent kernel source, a new build target
5204 "uImage" will exist which automatically builds an image usable by
5205 U-Boot. Most older kernels also have support for a "pImage" target,
5206 which was introduced for our predecessor project PPCBoot and uses a
5207 100% compatible format.
5216 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5217 encapsulate a compressed Linux kernel image with header information,
5218 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5220 * build a standard "vmlinux" kernel image (in ELF binary format):
5222 * convert the kernel into a raw binary image:
5224 ${CROSS_COMPILE}-objcopy -O binary \
5225 -R .note -R .comment \
5226 -S vmlinux linux.bin
5228 * compress the binary image:
5232 * package compressed binary image for U-Boot:
5234 mkimage -A ppc -O linux -T kernel -C gzip \
5235 -a 0 -e 0 -n "Linux Kernel Image" \
5236 -d linux.bin.gz uImage
5239 The "mkimage" tool can also be used to create ramdisk images for use
5240 with U-Boot, either separated from the Linux kernel image, or
5241 combined into one file. "mkimage" encapsulates the images with a 64
5242 byte header containing information about target architecture,
5243 operating system, image type, compression method, entry points, time
5244 stamp, CRC32 checksums, etc.
5246 "mkimage" can be called in two ways: to verify existing images and
5247 print the header information, or to build new images.
5249 In the first form (with "-l" option) mkimage lists the information
5250 contained in the header of an existing U-Boot image; this includes
5251 checksum verification:
5253 tools/mkimage -l image
5254 -l ==> list image header information
5256 The second form (with "-d" option) is used to build a U-Boot image
5257 from a "data file" which is used as image payload:
5259 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5260 -n name -d data_file image
5261 -A ==> set architecture to 'arch'
5262 -O ==> set operating system to 'os'
5263 -T ==> set image type to 'type'
5264 -C ==> set compression type 'comp'
5265 -a ==> set load address to 'addr' (hex)
5266 -e ==> set entry point to 'ep' (hex)
5267 -n ==> set image name to 'name'
5268 -d ==> use image data from 'datafile'
5270 Right now, all Linux kernels for PowerPC systems use the same load
5271 address (0x00000000), but the entry point address depends on the
5274 - 2.2.x kernels have the entry point at 0x0000000C,
5275 - 2.3.x and later kernels have the entry point at 0x00000000.
5277 So a typical call to build a U-Boot image would read:
5279 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5280 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5281 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5282 > examples/uImage.TQM850L
5283 Image Name: 2.4.4 kernel for TQM850L
5284 Created: Wed Jul 19 02:34:59 2000
5285 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5286 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5287 Load Address: 0x00000000
5288 Entry Point: 0x00000000
5290 To verify the contents of the image (or check for corruption):
5292 -> tools/mkimage -l examples/uImage.TQM850L
5293 Image Name: 2.4.4 kernel for TQM850L
5294 Created: Wed Jul 19 02:34:59 2000
5295 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5296 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5297 Load Address: 0x00000000
5298 Entry Point: 0x00000000
5300 NOTE: for embedded systems where boot time is critical you can trade
5301 speed for memory and install an UNCOMPRESSED image instead: this
5302 needs more space in Flash, but boots much faster since it does not
5303 need to be uncompressed:
5305 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5306 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5307 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5308 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5309 > examples/uImage.TQM850L-uncompressed
5310 Image Name: 2.4.4 kernel for TQM850L
5311 Created: Wed Jul 19 02:34:59 2000
5312 Image Type: PowerPC Linux Kernel Image (uncompressed)
5313 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5314 Load Address: 0x00000000
5315 Entry Point: 0x00000000
5318 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5319 when your kernel is intended to use an initial ramdisk:
5321 -> tools/mkimage -n 'Simple Ramdisk Image' \
5322 > -A ppc -O linux -T ramdisk -C gzip \
5323 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5324 Image Name: Simple Ramdisk Image
5325 Created: Wed Jan 12 14:01:50 2000
5326 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5327 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5328 Load Address: 0x00000000
5329 Entry Point: 0x00000000
5331 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5332 option performs the converse operation of the mkimage's second form (the "-d"
5333 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5336 tools/dumpimage -i image -p position data_file
5337 -i ==> extract from the 'image' a specific 'data_file', \
5338 indexed by 'position'
5341 Installing a Linux Image:
5342 -------------------------
5344 To downloading a U-Boot image over the serial (console) interface,
5345 you must convert the image to S-Record format:
5347 objcopy -I binary -O srec examples/image examples/image.srec
5349 The 'objcopy' does not understand the information in the U-Boot
5350 image header, so the resulting S-Record file will be relative to
5351 address 0x00000000. To load it to a given address, you need to
5352 specify the target address as 'offset' parameter with the 'loads'
5355 Example: install the image to address 0x40100000 (which on the
5356 TQM8xxL is in the first Flash bank):
5358 => erase 40100000 401FFFFF
5364 ## Ready for S-Record download ...
5365 ~>examples/image.srec
5366 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5368 15989 15990 15991 15992
5369 [file transfer complete]
5371 ## Start Addr = 0x00000000
5374 You can check the success of the download using the 'iminfo' command;
5375 this includes a checksum verification so you can be sure no data
5376 corruption happened:
5380 ## Checking Image at 40100000 ...
5381 Image Name: 2.2.13 for initrd on TQM850L
5382 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5383 Data Size: 335725 Bytes = 327 kB = 0 MB
5384 Load Address: 00000000
5385 Entry Point: 0000000c
5386 Verifying Checksum ... OK
5392 The "bootm" command is used to boot an application that is stored in
5393 memory (RAM or Flash). In case of a Linux kernel image, the contents
5394 of the "bootargs" environment variable is passed to the kernel as
5395 parameters. You can check and modify this variable using the
5396 "printenv" and "setenv" commands:
5399 => printenv bootargs
5400 bootargs=root=/dev/ram
5402 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5404 => printenv bootargs
5405 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5408 ## Booting Linux kernel at 40020000 ...
5409 Image Name: 2.2.13 for NFS on TQM850L
5410 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5411 Data Size: 381681 Bytes = 372 kB = 0 MB
5412 Load Address: 00000000
5413 Entry Point: 0000000c
5414 Verifying Checksum ... OK
5415 Uncompressing Kernel Image ... OK
5416 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
5417 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5418 time_init: decrementer frequency = 187500000/60
5419 Calibrating delay loop... 49.77 BogoMIPS
5420 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5423 If you want to boot a Linux kernel with initial RAM disk, you pass
5424 the memory addresses of both the kernel and the initrd image (PPBCOOT
5425 format!) to the "bootm" command:
5427 => imi 40100000 40200000
5429 ## Checking Image at 40100000 ...
5430 Image Name: 2.2.13 for initrd on TQM850L
5431 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5432 Data Size: 335725 Bytes = 327 kB = 0 MB
5433 Load Address: 00000000
5434 Entry Point: 0000000c
5435 Verifying Checksum ... OK
5437 ## Checking Image at 40200000 ...
5438 Image Name: Simple Ramdisk Image
5439 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5440 Data Size: 566530 Bytes = 553 kB = 0 MB
5441 Load Address: 00000000
5442 Entry Point: 00000000
5443 Verifying Checksum ... OK
5445 => bootm 40100000 40200000
5446 ## Booting Linux kernel at 40100000 ...
5447 Image Name: 2.2.13 for initrd on TQM850L
5448 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5449 Data Size: 335725 Bytes = 327 kB = 0 MB
5450 Load Address: 00000000
5451 Entry Point: 0000000c
5452 Verifying Checksum ... OK
5453 Uncompressing Kernel Image ... OK
5454 ## Loading RAMDisk Image at 40200000 ...
5455 Image Name: Simple Ramdisk Image
5456 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5457 Data Size: 566530 Bytes = 553 kB = 0 MB
5458 Load Address: 00000000
5459 Entry Point: 00000000
5460 Verifying Checksum ... OK
5461 Loading Ramdisk ... OK
5462 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
5463 Boot arguments: root=/dev/ram
5464 time_init: decrementer frequency = 187500000/60
5465 Calibrating delay loop... 49.77 BogoMIPS
5467 RAMDISK: Compressed image found at block 0
5468 VFS: Mounted root (ext2 filesystem).
5472 Boot Linux and pass a flat device tree:
5475 First, U-Boot must be compiled with the appropriate defines. See the section
5476 titled "Linux Kernel Interface" above for a more in depth explanation. The
5477 following is an example of how to start a kernel and pass an updated
5483 oft=oftrees/mpc8540ads.dtb
5484 => tftp $oftaddr $oft
5485 Speed: 1000, full duplex
5487 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5488 Filename 'oftrees/mpc8540ads.dtb'.
5489 Load address: 0x300000
5492 Bytes transferred = 4106 (100a hex)
5493 => tftp $loadaddr $bootfile
5494 Speed: 1000, full duplex
5496 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5498 Load address: 0x200000
5499 Loading:############
5501 Bytes transferred = 1029407 (fb51f hex)
5506 => bootm $loadaddr - $oftaddr
5507 ## Booting image at 00200000 ...
5508 Image Name: Linux-2.6.17-dirty
5509 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5510 Data Size: 1029343 Bytes = 1005.2 kB
5511 Load Address: 00000000
5512 Entry Point: 00000000
5513 Verifying Checksum ... OK
5514 Uncompressing Kernel Image ... OK
5515 Booting using flat device tree at 0x300000
5516 Using MPC85xx ADS machine description
5517 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5521 More About U-Boot Image Types:
5522 ------------------------------
5524 U-Boot supports the following image types:
5526 "Standalone Programs" are directly runnable in the environment
5527 provided by U-Boot; it is expected that (if they behave
5528 well) you can continue to work in U-Boot after return from
5529 the Standalone Program.
5530 "OS Kernel Images" are usually images of some Embedded OS which
5531 will take over control completely. Usually these programs
5532 will install their own set of exception handlers, device
5533 drivers, set up the MMU, etc. - this means, that you cannot
5534 expect to re-enter U-Boot except by resetting the CPU.
5535 "RAMDisk Images" are more or less just data blocks, and their
5536 parameters (address, size) are passed to an OS kernel that is
5538 "Multi-File Images" contain several images, typically an OS
5539 (Linux) kernel image and one or more data images like
5540 RAMDisks. This construct is useful for instance when you want
5541 to boot over the network using BOOTP etc., where the boot
5542 server provides just a single image file, but you want to get
5543 for instance an OS kernel and a RAMDisk image.
5545 "Multi-File Images" start with a list of image sizes, each
5546 image size (in bytes) specified by an "uint32_t" in network
5547 byte order. This list is terminated by an "(uint32_t)0".
5548 Immediately after the terminating 0 follow the images, one by
5549 one, all aligned on "uint32_t" boundaries (size rounded up to
5550 a multiple of 4 bytes).
5552 "Firmware Images" are binary images containing firmware (like
5553 U-Boot or FPGA images) which usually will be programmed to
5556 "Script files" are command sequences that will be executed by
5557 U-Boot's command interpreter; this feature is especially
5558 useful when you configure U-Boot to use a real shell (hush)
5559 as command interpreter.
5561 Booting the Linux zImage:
5562 -------------------------
5564 On some platforms, it's possible to boot Linux zImage. This is done
5565 using the "bootz" command. The syntax of "bootz" command is the same
5566 as the syntax of "bootm" command.
5568 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5569 kernel with raw initrd images. The syntax is slightly different, the
5570 address of the initrd must be augmented by it's size, in the following
5571 format: "<initrd addres>:<initrd size>".
5577 One of the features of U-Boot is that you can dynamically load and
5578 run "standalone" applications, which can use some resources of
5579 U-Boot like console I/O functions or interrupt services.
5581 Two simple examples are included with the sources:
5586 'examples/hello_world.c' contains a small "Hello World" Demo
5587 application; it is automatically compiled when you build U-Boot.
5588 It's configured to run at address 0x00040004, so you can play with it
5592 ## Ready for S-Record download ...
5593 ~>examples/hello_world.srec
5594 1 2 3 4 5 6 7 8 9 10 11 ...
5595 [file transfer complete]
5597 ## Start Addr = 0x00040004
5599 => go 40004 Hello World! This is a test.
5600 ## Starting application at 0x00040004 ...
5611 Hit any key to exit ...
5613 ## Application terminated, rc = 0x0
5615 Another example, which demonstrates how to register a CPM interrupt
5616 handler with the U-Boot code, can be found in 'examples/timer.c'.
5617 Here, a CPM timer is set up to generate an interrupt every second.
5618 The interrupt service routine is trivial, just printing a '.'
5619 character, but this is just a demo program. The application can be
5620 controlled by the following keys:
5622 ? - print current values og the CPM Timer registers
5623 b - enable interrupts and start timer
5624 e - stop timer and disable interrupts
5625 q - quit application
5628 ## Ready for S-Record download ...
5629 ~>examples/timer.srec
5630 1 2 3 4 5 6 7 8 9 10 11 ...
5631 [file transfer complete]
5633 ## Start Addr = 0x00040004
5636 ## Starting application at 0x00040004 ...
5639 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5642 [q, b, e, ?] Set interval 1000000 us
5645 [q, b, e, ?] ........
5646 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5649 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5652 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5655 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5657 [q, b, e, ?] ...Stopping timer
5659 [q, b, e, ?] ## Application terminated, rc = 0x0
5665 Over time, many people have reported problems when trying to use the
5666 "minicom" terminal emulation program for serial download. I (wd)
5667 consider minicom to be broken, and recommend not to use it. Under
5668 Unix, I recommend to use C-Kermit for general purpose use (and
5669 especially for kermit binary protocol download ("loadb" command), and
5670 use "cu" for S-Record download ("loads" command). See
5671 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5672 for help with kermit.
5675 Nevertheless, if you absolutely want to use it try adding this
5676 configuration to your "File transfer protocols" section:
5678 Name Program Name U/D FullScr IO-Red. Multi
5679 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5680 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5686 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5687 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5689 Building requires a cross environment; it is known to work on
5690 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5691 need gmake since the Makefiles are not compatible with BSD make).
5692 Note that the cross-powerpc package does not install include files;
5693 attempting to build U-Boot will fail because <machine/ansi.h> is
5694 missing. This file has to be installed and patched manually:
5696 # cd /usr/pkg/cross/powerpc-netbsd/include
5698 # ln -s powerpc machine
5699 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5700 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5702 Native builds *don't* work due to incompatibilities between native
5703 and U-Boot include files.
5705 Booting assumes that (the first part of) the image booted is a
5706 stage-2 loader which in turn loads and then invokes the kernel
5707 proper. Loader sources will eventually appear in the NetBSD source
5708 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5709 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5712 Implementation Internals:
5713 =========================
5715 The following is not intended to be a complete description of every
5716 implementation detail. However, it should help to understand the
5717 inner workings of U-Boot and make it easier to port it to custom
5721 Initial Stack, Global Data:
5722 ---------------------------
5724 The implementation of U-Boot is complicated by the fact that U-Boot
5725 starts running out of ROM (flash memory), usually without access to
5726 system RAM (because the memory controller is not initialized yet).
5727 This means that we don't have writable Data or BSS segments, and BSS
5728 is not initialized as zero. To be able to get a C environment working
5729 at all, we have to allocate at least a minimal stack. Implementation
5730 options for this are defined and restricted by the CPU used: Some CPU
5731 models provide on-chip memory (like the IMMR area on MPC8xx and
5732 MPC826x processors), on others (parts of) the data cache can be
5733 locked as (mis-) used as memory, etc.
5735 Chris Hallinan posted a good summary of these issues to the
5736 U-Boot mailing list:
5738 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5739 From: "Chris Hallinan" <clh@net1plus.com>
5740 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5743 Correct me if I'm wrong, folks, but the way I understand it
5744 is this: Using DCACHE as initial RAM for Stack, etc, does not
5745 require any physical RAM backing up the cache. The cleverness
5746 is that the cache is being used as a temporary supply of
5747 necessary storage before the SDRAM controller is setup. It's
5748 beyond the scope of this list to explain the details, but you
5749 can see how this works by studying the cache architecture and
5750 operation in the architecture and processor-specific manuals.
5752 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5753 is another option for the system designer to use as an
5754 initial stack/RAM area prior to SDRAM being available. Either
5755 option should work for you. Using CS 4 should be fine if your
5756 board designers haven't used it for something that would
5757 cause you grief during the initial boot! It is frequently not
5760 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5761 with your processor/board/system design. The default value
5762 you will find in any recent u-boot distribution in
5763 walnut.h should work for you. I'd set it to a value larger
5764 than your SDRAM module. If you have a 64MB SDRAM module, set
5765 it above 400_0000. Just make sure your board has no resources
5766 that are supposed to respond to that address! That code in
5767 start.S has been around a while and should work as is when
5768 you get the config right.
5773 It is essential to remember this, since it has some impact on the C
5774 code for the initialization procedures:
5776 * Initialized global data (data segment) is read-only. Do not attempt
5779 * Do not use any uninitialized global data (or implicitely initialized
5780 as zero data - BSS segment) at all - this is undefined, initiali-
5781 zation is performed later (when relocating to RAM).
5783 * Stack space is very limited. Avoid big data buffers or things like
5786 Having only the stack as writable memory limits means we cannot use
5787 normal global data to share information beween the code. But it
5788 turned out that the implementation of U-Boot can be greatly
5789 simplified by making a global data structure (gd_t) available to all
5790 functions. We could pass a pointer to this data as argument to _all_
5791 functions, but this would bloat the code. Instead we use a feature of
5792 the GCC compiler (Global Register Variables) to share the data: we
5793 place a pointer (gd) to the global data into a register which we
5794 reserve for this purpose.
5796 When choosing a register for such a purpose we are restricted by the
5797 relevant (E)ABI specifications for the current architecture, and by
5798 GCC's implementation.
5800 For PowerPC, the following registers have specific use:
5802 R2: reserved for system use
5803 R3-R4: parameter passing and return values
5804 R5-R10: parameter passing
5805 R13: small data area pointer
5809 (U-Boot also uses R12 as internal GOT pointer. r12
5810 is a volatile register so r12 needs to be reset when
5811 going back and forth between asm and C)
5813 ==> U-Boot will use R2 to hold a pointer to the global data
5815 Note: on PPC, we could use a static initializer (since the
5816 address of the global data structure is known at compile time),
5817 but it turned out that reserving a register results in somewhat
5818 smaller code - although the code savings are not that big (on
5819 average for all boards 752 bytes for the whole U-Boot image,
5820 624 text + 127 data).
5822 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5823 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5825 ==> U-Boot will use P3 to hold a pointer to the global data
5827 On ARM, the following registers are used:
5829 R0: function argument word/integer result
5830 R1-R3: function argument word
5831 R9: platform specific
5832 R10: stack limit (used only if stack checking is enabled)
5833 R11: argument (frame) pointer
5834 R12: temporary workspace
5837 R15: program counter
5839 ==> U-Boot will use R9 to hold a pointer to the global data
5841 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5843 On Nios II, the ABI is documented here:
5844 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5846 ==> U-Boot will use gp to hold a pointer to the global data
5848 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5849 to access small data sections, so gp is free.
5851 On NDS32, the following registers are used:
5853 R0-R1: argument/return
5855 R15: temporary register for assembler
5856 R16: trampoline register
5857 R28: frame pointer (FP)
5858 R29: global pointer (GP)
5859 R30: link register (LP)
5860 R31: stack pointer (SP)
5861 PC: program counter (PC)
5863 ==> U-Boot will use R10 to hold a pointer to the global data
5865 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5866 or current versions of GCC may "optimize" the code too much.
5871 U-Boot runs in system state and uses physical addresses, i.e. the
5872 MMU is not used either for address mapping nor for memory protection.
5874 The available memory is mapped to fixed addresses using the memory
5875 controller. In this process, a contiguous block is formed for each
5876 memory type (Flash, SDRAM, SRAM), even when it consists of several
5877 physical memory banks.
5879 U-Boot is installed in the first 128 kB of the first Flash bank (on
5880 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5881 booting and sizing and initializing DRAM, the code relocates itself
5882 to the upper end of DRAM. Immediately below the U-Boot code some
5883 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5884 configuration setting]. Below that, a structure with global Board
5885 Info data is placed, followed by the stack (growing downward).
5887 Additionally, some exception handler code is copied to the low 8 kB
5888 of DRAM (0x00000000 ... 0x00001FFF).
5890 So a typical memory configuration with 16 MB of DRAM could look like
5893 0x0000 0000 Exception Vector code
5896 0x0000 2000 Free for Application Use
5902 0x00FB FF20 Monitor Stack (Growing downward)
5903 0x00FB FFAC Board Info Data and permanent copy of global data
5904 0x00FC 0000 Malloc Arena
5907 0x00FE 0000 RAM Copy of Monitor Code
5908 ... eventually: LCD or video framebuffer
5909 ... eventually: pRAM (Protected RAM - unchanged by reset)
5910 0x00FF FFFF [End of RAM]
5913 System Initialization:
5914 ----------------------
5916 In the reset configuration, U-Boot starts at the reset entry point
5917 (on most PowerPC systems at address 0x00000100). Because of the reset
5918 configuration for CS0# this is a mirror of the onboard Flash memory.
5919 To be able to re-map memory U-Boot then jumps to its link address.
5920 To be able to implement the initialization code in C, a (small!)
5921 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5922 which provide such a feature like MPC8xx or MPC8260), or in a locked
5923 part of the data cache. After that, U-Boot initializes the CPU core,
5924 the caches and the SIU.
5926 Next, all (potentially) available memory banks are mapped using a
5927 preliminary mapping. For example, we put them on 512 MB boundaries
5928 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5929 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5930 programmed for SDRAM access. Using the temporary configuration, a
5931 simple memory test is run that determines the size of the SDRAM
5934 When there is more than one SDRAM bank, and the banks are of
5935 different size, the largest is mapped first. For equal size, the first
5936 bank (CS2#) is mapped first. The first mapping is always for address
5937 0x00000000, with any additional banks following immediately to create
5938 contiguous memory starting from 0.
5940 Then, the monitor installs itself at the upper end of the SDRAM area
5941 and allocates memory for use by malloc() and for the global Board
5942 Info data; also, the exception vector code is copied to the low RAM
5943 pages, and the final stack is set up.
5945 Only after this relocation will you have a "normal" C environment;
5946 until that you are restricted in several ways, mostly because you are
5947 running from ROM, and because the code will have to be relocated to a
5951 U-Boot Porting Guide:
5952 ----------------------
5954 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5958 int main(int argc, char *argv[])
5960 sighandler_t no_more_time;
5962 signal(SIGALRM, no_more_time);
5963 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5965 if (available_money > available_manpower) {
5966 Pay consultant to port U-Boot;
5970 Download latest U-Boot source;
5972 Subscribe to u-boot mailing list;
5975 email("Hi, I am new to U-Boot, how do I get started?");
5978 Read the README file in the top level directory;
5979 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5980 Read applicable doc/*.README;
5981 Read the source, Luke;
5982 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5985 if (available_money > toLocalCurrency ($2500))
5988 Add a lot of aggravation and time;
5990 if (a similar board exists) { /* hopefully... */
5991 cp -a board/<similar> board/<myboard>
5992 cp include/configs/<similar>.h include/configs/<myboard>.h
5994 Create your own board support subdirectory;
5995 Create your own board include/configs/<myboard>.h file;
5997 Edit new board/<myboard> files
5998 Edit new include/configs/<myboard>.h
6003 Add / modify source code;
6007 email("Hi, I am having problems...");
6009 Send patch file to the U-Boot email list;
6010 if (reasonable critiques)
6011 Incorporate improvements from email list code review;
6013 Defend code as written;
6019 void no_more_time (int sig)
6028 All contributions to U-Boot should conform to the Linux kernel
6029 coding style; see the file "Documentation/CodingStyle" and the script
6030 "scripts/Lindent" in your Linux kernel source directory.
6032 Source files originating from a different project (for example the
6033 MTD subsystem) are generally exempt from these guidelines and are not
6034 reformated to ease subsequent migration to newer versions of those
6037 Please note that U-Boot is implemented in C (and to some small parts in
6038 Assembler); no C++ is used, so please do not use C++ style comments (//)
6041 Please also stick to the following formatting rules:
6042 - remove any trailing white space
6043 - use TAB characters for indentation and vertical alignment, not spaces
6044 - make sure NOT to use DOS '\r\n' line feeds
6045 - do not add more than 2 consecutive empty lines to source files
6046 - do not add trailing empty lines to source files
6048 Submissions which do not conform to the standards may be returned
6049 with a request to reformat the changes.
6055 Since the number of patches for U-Boot is growing, we need to
6056 establish some rules. Submissions which do not conform to these rules
6057 may be rejected, even when they contain important and valuable stuff.
6059 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6061 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6062 see http://lists.denx.de/mailman/listinfo/u-boot
6064 When you send a patch, please include the following information with
6067 * For bug fixes: a description of the bug and how your patch fixes
6068 this bug. Please try to include a way of demonstrating that the
6069 patch actually fixes something.
6071 * For new features: a description of the feature and your
6074 * A CHANGELOG entry as plaintext (separate from the patch)
6076 * For major contributions, your entry to the CREDITS file
6078 * When you add support for a new board, don't forget to add a
6079 maintainer e-mail address to the boards.cfg file, too.
6081 * If your patch adds new configuration options, don't forget to
6082 document these in the README file.
6084 * The patch itself. If you are using git (which is *strongly*
6085 recommended) you can easily generate the patch using the
6086 "git format-patch". If you then use "git send-email" to send it to
6087 the U-Boot mailing list, you will avoid most of the common problems
6088 with some other mail clients.
6090 If you cannot use git, use "diff -purN OLD NEW". If your version of
6091 diff does not support these options, then get the latest version of
6094 The current directory when running this command shall be the parent
6095 directory of the U-Boot source tree (i. e. please make sure that
6096 your patch includes sufficient directory information for the
6099 We prefer patches as plain text. MIME attachments are discouraged,
6100 and compressed attachments must not be used.
6102 * If one logical set of modifications affects or creates several
6103 files, all these changes shall be submitted in a SINGLE patch file.
6105 * Changesets that contain different, unrelated modifications shall be
6106 submitted as SEPARATE patches, one patch per changeset.
6111 * Before sending the patch, run the MAKEALL script on your patched
6112 source tree and make sure that no errors or warnings are reported
6113 for any of the boards.
6115 * Keep your modifications to the necessary minimum: A patch
6116 containing several unrelated changes or arbitrary reformats will be
6117 returned with a request to re-formatting / split it.
6119 * If you modify existing code, make sure that your new code does not
6120 add to the memory footprint of the code ;-) Small is beautiful!
6121 When adding new features, these should compile conditionally only
6122 (using #ifdef), and the resulting code with the new feature
6123 disabled must not need more memory than the old code without your
6126 * Remember that there is a size limit of 100 kB per message on the
6127 u-boot mailing list. Bigger patches will be moderated. If they are
6128 reasonable and not too big, they will be acknowledged. But patches
6129 bigger than the size limit should be avoided.
projects / platform / kernel / u-boot.git / blob