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
570 If set, the workarounds for these ARM errata are applied early
571 during U-Boot startup. Note that these options force the
572 workarounds to be applied; no CPU-type/version detection
573 exists, unlike the similar options in the Linux kernel. Do not
574 set these options unless they apply!
579 The frequency of the timer returned by get_timer().
580 get_timer() must operate in milliseconds and this CONFIG
581 option must be set to 1000.
583 - Linux Kernel Interface:
586 U-Boot stores all clock information in Hz
587 internally. For binary compatibility with older Linux
588 kernels (which expect the clocks passed in the
589 bd_info data to be in MHz) the environment variable
590 "clocks_in_mhz" can be defined so that U-Boot
591 converts clock data to MHZ before passing it to the
593 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
594 "clocks_in_mhz=1" is automatically included in the
597 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
599 When transferring memsize parameter to linux, some versions
600 expect it to be in bytes, others in MB.
601 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
605 New kernel versions are expecting firmware settings to be
606 passed using flattened device trees (based on open firmware
610 * New libfdt-based support
611 * Adds the "fdt" command
612 * The bootm command automatically updates the fdt
614 OF_CPU - The proper name of the cpus node (only required for
615 MPC512X and MPC5xxx based boards).
616 OF_SOC - The proper name of the soc node (only required for
617 MPC512X and MPC5xxx based boards).
618 OF_TBCLK - The timebase frequency.
619 OF_STDOUT_PATH - The path to the console device
621 boards with QUICC Engines require OF_QE to set UCC MAC
624 CONFIG_OF_BOARD_SETUP
626 Board code has addition modification that it wants to make
627 to the flat device tree before handing it off to the kernel
631 This define fills in the correct boot CPU in the boot
632 param header, the default value is zero if undefined.
636 U-Boot can detect if an IDE device is present or not.
637 If not, and this new config option is activated, U-Boot
638 removes the ATA node from the DTS before booting Linux,
639 so the Linux IDE driver does not probe the device and
640 crash. This is needed for buggy hardware (uc101) where
641 no pull down resistor is connected to the signal IDE5V_DD7.
643 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
645 This setting is mandatory for all boards that have only one
646 machine type and must be used to specify the machine type
647 number as it appears in the ARM machine registry
648 (see http://www.arm.linux.org.uk/developer/machines/).
649 Only boards that have multiple machine types supported
650 in a single configuration file and the machine type is
651 runtime discoverable, do not have to use this setting.
653 - vxWorks boot parameters:
655 bootvx constructs a valid bootline using the following
656 environments variables: bootfile, ipaddr, serverip, hostname.
657 It loads the vxWorks image pointed bootfile.
659 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
660 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
661 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
662 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
664 CONFIG_SYS_VXWORKS_ADD_PARAMS
666 Add it at the end of the bootline. E.g "u=username pw=secret"
668 Note: If a "bootargs" environment is defined, it will overwride
669 the defaults discussed just above.
671 - Cache Configuration:
672 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
673 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
674 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
676 - Cache Configuration for ARM:
677 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
679 CONFIG_SYS_PL310_BASE - Physical base address of PL310
680 controller register space
685 Define this if you want support for Amba PrimeCell PL010 UARTs.
689 Define this if you want support for Amba PrimeCell PL011 UARTs.
693 If you have Amba PrimeCell PL011 UARTs, set this variable to
694 the clock speed of the UARTs.
698 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
699 define this to a list of base addresses for each (supported)
700 port. See e.g. include/configs/versatile.h
702 CONFIG_PL011_SERIAL_RLCR
704 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
705 have separate receive and transmit line control registers. Set
706 this variable to initialize the extra register.
708 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
710 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
711 boot loader that has already initialized the UART. Define this
712 variable to flush the UART at init time.
716 Depending on board, define exactly one serial port
717 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
718 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
719 console by defining CONFIG_8xx_CONS_NONE
721 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
722 port routines must be defined elsewhere
723 (i.e. serial_init(), serial_getc(), ...)
726 Enables console device for a color framebuffer. Needs following
727 defines (cf. smiLynxEM, i8042)
728 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
730 VIDEO_HW_RECTFILL graphic chip supports
733 VIDEO_HW_BITBLT graphic chip supports
734 bit-blit (cf. smiLynxEM)
735 VIDEO_VISIBLE_COLS visible pixel columns
737 VIDEO_VISIBLE_ROWS visible pixel rows
738 VIDEO_PIXEL_SIZE bytes per pixel
739 VIDEO_DATA_FORMAT graphic data format
740 (0-5, cf. cfb_console.c)
741 VIDEO_FB_ADRS framebuffer address
742 VIDEO_KBD_INIT_FCT keyboard int fct
743 (i.e. i8042_kbd_init())
744 VIDEO_TSTC_FCT test char fct
746 VIDEO_GETC_FCT get char fct
748 CONFIG_CONSOLE_CURSOR cursor drawing on/off
749 (requires blink timer
751 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
752 CONFIG_CONSOLE_TIME display time/date info in
754 (requires CONFIG_CMD_DATE)
755 CONFIG_VIDEO_LOGO display Linux logo in
757 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
758 linux_logo.h for logo.
759 Requires CONFIG_VIDEO_LOGO
760 CONFIG_CONSOLE_EXTRA_INFO
761 additional board info beside
764 When CONFIG_CFB_CONSOLE_ANSI is defined, console will support
765 a limited number of ANSI escape sequences (cursor control,
766 erase functions and limited graphics rendition control).
768 When CONFIG_CFB_CONSOLE is defined, video console is
769 default i/o. Serial console can be forced with
770 environment 'console=serial'.
772 When CONFIG_SILENT_CONSOLE is defined, all console
773 messages (by U-Boot and Linux!) can be silenced with
774 the "silent" environment variable. See
775 doc/README.silent for more information.
777 CONFIG_SYS_CONSOLE_BG_COL: define the backgroundcolor, default
779 CONFIG_SYS_CONSOLE_FG_COL: define the foregroundcolor, default
783 CONFIG_BAUDRATE - in bps
784 Select one of the baudrates listed in
785 CONFIG_SYS_BAUDRATE_TABLE, see below.
786 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
788 - Console Rx buffer length
789 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
790 the maximum receive buffer length for the SMC.
791 This option is actual only for 82xx and 8xx possible.
792 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
793 must be defined, to setup the maximum idle timeout for
796 - Pre-Console Buffer:
797 Prior to the console being initialised (i.e. serial UART
798 initialised etc) all console output is silently discarded.
799 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
800 buffer any console messages prior to the console being
801 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
802 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
803 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
804 bytes are output before the console is initialised, the
805 earlier bytes are discarded.
807 'Sane' compilers will generate smaller code if
808 CONFIG_PRE_CON_BUF_SZ is a power of 2
810 - Safe printf() functions
811 Define CONFIG_SYS_VSNPRINTF to compile in safe versions of
812 the printf() functions. These are defined in
813 include/vsprintf.h and include snprintf(), vsnprintf() and
814 so on. Code size increase is approximately 300-500 bytes.
815 If this option is not given then these functions will
816 silently discard their buffer size argument - this means
817 you are not getting any overflow checking in this case.
819 - Boot Delay: CONFIG_BOOTDELAY - in seconds
820 Delay before automatically booting the default image;
821 set to -1 to disable autoboot.
822 set to -2 to autoboot with no delay and not check for abort
823 (even when CONFIG_ZERO_BOOTDELAY_CHECK is defined).
825 See doc/README.autoboot for these options that
826 work with CONFIG_BOOTDELAY. None are required.
827 CONFIG_BOOT_RETRY_TIME
828 CONFIG_BOOT_RETRY_MIN
829 CONFIG_AUTOBOOT_KEYED
830 CONFIG_AUTOBOOT_PROMPT
831 CONFIG_AUTOBOOT_DELAY_STR
832 CONFIG_AUTOBOOT_STOP_STR
833 CONFIG_AUTOBOOT_DELAY_STR2
834 CONFIG_AUTOBOOT_STOP_STR2
835 CONFIG_ZERO_BOOTDELAY_CHECK
836 CONFIG_RESET_TO_RETRY
840 Only needed when CONFIG_BOOTDELAY is enabled;
841 define a command string that is automatically executed
842 when no character is read on the console interface
843 within "Boot Delay" after reset.
846 This can be used to pass arguments to the bootm
847 command. The value of CONFIG_BOOTARGS goes into the
848 environment value "bootargs".
850 CONFIG_RAMBOOT and CONFIG_NFSBOOT
851 The value of these goes into the environment as
852 "ramboot" and "nfsboot" respectively, and can be used
853 as a convenience, when switching between booting from
857 CONFIG_BOOTCOUNT_LIMIT
858 Implements a mechanism for detecting a repeating reboot
860 http://www.denx.de/wiki/view/DULG/UBootBootCountLimit
863 If no softreset save registers are found on the hardware
864 "bootcount" is stored in the environment. To prevent a
865 saveenv on all reboots, the environment variable
866 "upgrade_available" is used. If "upgrade_available" is
867 0, "bootcount" is always 0, if "upgrade_available" is
868 1 "bootcount" is incremented in the environment.
869 So the Userspace Applikation must set the "upgrade_available"
870 and "bootcount" variable to 0, if a boot was successfully.
875 When this option is #defined, the existence of the
876 environment variable "preboot" will be checked
877 immediately before starting the CONFIG_BOOTDELAY
878 countdown and/or running the auto-boot command resp.
879 entering interactive mode.
881 This feature is especially useful when "preboot" is
882 automatically generated or modified. For an example
883 see the LWMON board specific code: here "preboot" is
884 modified when the user holds down a certain
885 combination of keys on the (special) keyboard when
888 - Serial Download Echo Mode:
890 If defined to 1, all characters received during a
891 serial download (using the "loads" command) are
892 echoed back. This might be needed by some terminal
893 emulations (like "cu"), but may as well just take
894 time on others. This setting #define's the initial
895 value of the "loads_echo" environment variable.
897 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
899 Select one of the baudrates listed in
900 CONFIG_SYS_BAUDRATE_TABLE, see below.
903 Monitor commands can be included or excluded
904 from the build by using the #include files
905 <config_cmd_all.h> and #undef'ing unwanted
906 commands, or using <config_cmd_default.h>
907 and augmenting with additional #define's
910 The default command configuration includes all commands
911 except those marked below with a "*".
913 CONFIG_CMD_ASKENV * ask for env variable
914 CONFIG_CMD_BDI bdinfo
915 CONFIG_CMD_BEDBUG * Include BedBug Debugger
916 CONFIG_CMD_BMP * BMP support
917 CONFIG_CMD_BSP * Board specific commands
918 CONFIG_CMD_BOOTD bootd
919 CONFIG_CMD_CACHE * icache, dcache
920 CONFIG_CMD_CLK * clock command support
921 CONFIG_CMD_CONSOLE coninfo
922 CONFIG_CMD_CRC32 * crc32
923 CONFIG_CMD_DATE * support for RTC, date/time...
924 CONFIG_CMD_DHCP * DHCP support
925 CONFIG_CMD_DIAG * Diagnostics
926 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
927 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
928 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
929 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
930 CONFIG_CMD_DTT * Digital Therm and Thermostat
931 CONFIG_CMD_ECHO echo arguments
932 CONFIG_CMD_EDITENV edit env variable
933 CONFIG_CMD_EEPROM * EEPROM read/write support
934 CONFIG_CMD_ELF * bootelf, bootvx
935 CONFIG_CMD_ENV_CALLBACK * display details about env callbacks
936 CONFIG_CMD_ENV_FLAGS * display details about env flags
937 CONFIG_CMD_ENV_EXISTS * check existence of env variable
938 CONFIG_CMD_EXPORTENV * export the environment
939 CONFIG_CMD_EXT2 * ext2 command support
940 CONFIG_CMD_EXT4 * ext4 command support
941 CONFIG_CMD_FS_GENERIC * filesystem commands (e.g. load, ls)
942 that work for multiple fs types
943 CONFIG_CMD_SAVEENV saveenv
944 CONFIG_CMD_FDC * Floppy Disk Support
945 CONFIG_CMD_FAT * FAT command support
946 CONFIG_CMD_FLASH flinfo, erase, protect
947 CONFIG_CMD_FPGA FPGA device initialization support
948 CONFIG_CMD_FUSE * Device fuse support
949 CONFIG_CMD_GETTIME * Get time since boot
950 CONFIG_CMD_GO * the 'go' command (exec code)
951 CONFIG_CMD_GREPENV * search environment
952 CONFIG_CMD_HASH * calculate hash / digest
953 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
954 CONFIG_CMD_I2C * I2C serial bus support
955 CONFIG_CMD_IDE * IDE harddisk support
956 CONFIG_CMD_IMI iminfo
957 CONFIG_CMD_IMLS List all images found in NOR flash
958 CONFIG_CMD_IMLS_NAND * List all images found in NAND flash
959 CONFIG_CMD_IMMAP * IMMR dump support
960 CONFIG_CMD_IMPORTENV * import an environment
961 CONFIG_CMD_INI * import data from an ini file into the env
962 CONFIG_CMD_IRQ * irqinfo
963 CONFIG_CMD_ITEST Integer/string test of 2 values
964 CONFIG_CMD_JFFS2 * JFFS2 Support
965 CONFIG_CMD_KGDB * kgdb
966 CONFIG_CMD_LDRINFO * ldrinfo (display Blackfin loader)
967 CONFIG_CMD_LINK_LOCAL * link-local IP address auto-configuration
969 CONFIG_CMD_LOADB loadb
970 CONFIG_CMD_LOADS loads
971 CONFIG_CMD_MD5SUM * print md5 message digest
972 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
973 CONFIG_CMD_MEMINFO * Display detailed memory information
974 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
976 CONFIG_CMD_MEMTEST * mtest
977 CONFIG_CMD_MISC Misc functions like sleep etc
978 CONFIG_CMD_MMC * MMC memory mapped support
979 CONFIG_CMD_MII * MII utility commands
980 CONFIG_CMD_MTDPARTS * MTD partition support
981 CONFIG_CMD_NAND * NAND support
982 CONFIG_CMD_NET bootp, tftpboot, rarpboot
983 CONFIG_CMD_NFS NFS support
984 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
985 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
986 CONFIG_CMD_PCI * pciinfo
987 CONFIG_CMD_PCMCIA * PCMCIA support
988 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
990 CONFIG_CMD_PORTIO * Port I/O
991 CONFIG_CMD_READ * Read raw data from partition
992 CONFIG_CMD_REGINFO * Register dump
993 CONFIG_CMD_RUN run command in env variable
994 CONFIG_CMD_SANDBOX * sb command to access sandbox features
995 CONFIG_CMD_SAVES * save S record dump
996 CONFIG_CMD_SCSI * SCSI Support
997 CONFIG_CMD_SDRAM * print SDRAM configuration information
998 (requires CONFIG_CMD_I2C)
999 CONFIG_CMD_SETGETDCR Support for DCR Register access
1001 CONFIG_CMD_SF * Read/write/erase SPI NOR flash
1002 CONFIG_CMD_SHA1SUM * print sha1 memory digest
1003 (requires CONFIG_CMD_MEMORY)
1004 CONFIG_CMD_SOFTSWITCH * Soft switch setting command for BF60x
1005 CONFIG_CMD_SOURCE "source" command Support
1006 CONFIG_CMD_SPI * SPI serial bus support
1007 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
1008 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
1009 CONFIG_CMD_TIME * run command and report execution time (ARM specific)
1010 CONFIG_CMD_TIMER * access to the system tick timer
1011 CONFIG_CMD_USB * USB support
1012 CONFIG_CMD_CDP * Cisco Discover Protocol support
1013 CONFIG_CMD_MFSL * Microblaze FSL support
1014 CONFIG_CMD_XIMG Load part of Multi Image
1017 EXAMPLE: If you want all functions except of network
1018 support you can write:
1020 #include "config_cmd_all.h"
1021 #undef CONFIG_CMD_NET
1024 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
1026 Note: Don't enable the "icache" and "dcache" commands
1027 (configuration option CONFIG_CMD_CACHE) unless you know
1028 what you (and your U-Boot users) are doing. Data
1029 cache cannot be enabled on systems like the 8xx or
1030 8260 (where accesses to the IMMR region must be
1031 uncached), and it cannot be disabled on all other
1032 systems where we (mis-) use the data cache to hold an
1033 initial stack and some data.
1036 XXX - this list needs to get updated!
1038 - Regular expression support:
1040 If this variable is defined, U-Boot is linked against
1041 the SLRE (Super Light Regular Expression) library,
1042 which adds regex support to some commands, as for
1043 example "env grep" and "setexpr".
1047 If this variable is defined, U-Boot will use a device tree
1048 to configure its devices, instead of relying on statically
1049 compiled #defines in the board file. This option is
1050 experimental and only available on a few boards. The device
1051 tree is available in the global data as gd->fdt_blob.
1053 U-Boot needs to get its device tree from somewhere. This can
1054 be done using one of the two options below:
1057 If this variable is defined, U-Boot will embed a device tree
1058 binary in its image. This device tree file should be in the
1059 board directory and called <soc>-<board>.dts. The binary file
1060 is then picked up in board_init_f() and made available through
1061 the global data structure as gd->blob.
1064 If this variable is defined, U-Boot will build a device tree
1065 binary. It will be called u-boot.dtb. Architecture-specific
1066 code will locate it at run-time. Generally this works by:
1068 cat u-boot.bin u-boot.dtb >image.bin
1070 and in fact, U-Boot does this for you, creating a file called
1071 u-boot-dtb.bin which is useful in the common case. You can
1072 still use the individual files if you need something more
1077 If this variable is defined, it enables watchdog
1078 support for the SoC. There must be support in the SoC
1079 specific code for a watchdog. For the 8xx and 8260
1080 CPUs, the SIU Watchdog feature is enabled in the SYPCR
1081 register. When supported for a specific SoC is
1082 available, then no further board specific code should
1083 be needed to use it.
1086 When using a watchdog circuitry external to the used
1087 SoC, then define this variable and provide board
1088 specific code for the "hw_watchdog_reset" function.
1091 CONFIG_VERSION_VARIABLE
1092 If this variable is defined, an environment variable
1093 named "ver" is created by U-Boot showing the U-Boot
1094 version as printed by the "version" command.
1095 Any change to this variable will be reverted at the
1100 When CONFIG_CMD_DATE is selected, the type of the RTC
1101 has to be selected, too. Define exactly one of the
1104 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
1105 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
1106 CONFIG_RTC_MC13XXX - use MC13783 or MC13892 RTC
1107 CONFIG_RTC_MC146818 - use MC146818 RTC
1108 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
1109 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
1110 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
1111 CONFIG_RTC_DS164x - use Dallas DS164x RTC
1112 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
1113 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
1114 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
1115 CONFIG_SYS_RV3029_TCR - enable trickle charger on
1118 Note that if the RTC uses I2C, then the I2C interface
1119 must also be configured. See I2C Support, below.
1122 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
1124 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
1125 chip-ngpio pairs that tell the PCA953X driver the number of
1126 pins supported by a particular chip.
1128 Note that if the GPIO device uses I2C, then the I2C interface
1129 must also be configured. See I2C Support, below.
1131 - Timestamp Support:
1133 When CONFIG_TIMESTAMP is selected, the timestamp
1134 (date and time) of an image is printed by image
1135 commands like bootm or iminfo. This option is
1136 automatically enabled when you select CONFIG_CMD_DATE .
1138 - Partition Labels (disklabels) Supported:
1139 Zero or more of the following:
1140 CONFIG_MAC_PARTITION Apple's MacOS partition table.
1141 CONFIG_DOS_PARTITION MS Dos partition table, traditional on the
1142 Intel architecture, USB sticks, etc.
1143 CONFIG_ISO_PARTITION ISO partition table, used on CDROM etc.
1144 CONFIG_EFI_PARTITION GPT partition table, common when EFI is the
1145 bootloader. Note 2TB partition limit; see
1147 CONFIG_MTD_PARTITIONS Memory Technology Device partition table.
1149 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
1150 CONFIG_CMD_SCSI) you must configure support for at
1151 least one non-MTD partition type as well.
1154 CONFIG_IDE_RESET_ROUTINE - this is defined in several
1155 board configurations files but used nowhere!
1157 CONFIG_IDE_RESET - is this is defined, IDE Reset will
1158 be performed by calling the function
1159 ide_set_reset(int reset)
1160 which has to be defined in a board specific file
1165 Set this to enable ATAPI support.
1170 Set this to enable support for disks larger than 137GB
1171 Also look at CONFIG_SYS_64BIT_LBA.
1172 Whithout these , LBA48 support uses 32bit variables and will 'only'
1173 support disks up to 2.1TB.
1175 CONFIG_SYS_64BIT_LBA:
1176 When enabled, makes the IDE subsystem use 64bit sector addresses.
1180 At the moment only there is only support for the
1181 SYM53C8XX SCSI controller; define
1182 CONFIG_SCSI_SYM53C8XX to enable it.
1184 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
1185 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
1186 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
1187 maximum numbers of LUNs, SCSI ID's and target
1189 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
1191 The environment variable 'scsidevs' is set to the number of
1192 SCSI devices found during the last scan.
1194 - NETWORK Support (PCI):
1196 Support for Intel 8254x/8257x gigabit chips.
1199 Utility code for direct access to the SPI bus on Intel 8257x.
1200 This does not do anything useful unless you set at least one
1201 of CONFIG_CMD_E1000 or CONFIG_E1000_SPI_GENERIC.
1203 CONFIG_E1000_SPI_GENERIC
1204 Allow generic access to the SPI bus on the Intel 8257x, for
1205 example with the "sspi" command.
1208 Management command for E1000 devices. When used on devices
1209 with SPI support you can reprogram the EEPROM from U-Boot.
1211 CONFIG_E1000_FALLBACK_MAC
1212 default MAC for empty EEPROM after production.
1215 Support for Intel 82557/82559/82559ER chips.
1216 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
1217 write routine for first time initialisation.
1220 Support for Digital 2114x chips.
1221 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
1222 modem chip initialisation (KS8761/QS6611).
1225 Support for National dp83815 chips.
1228 Support for National dp8382[01] gigabit chips.
1230 - NETWORK Support (other):
1232 CONFIG_DRIVER_AT91EMAC
1233 Support for AT91RM9200 EMAC.
1236 Define this to use reduced MII inteface
1238 CONFIG_DRIVER_AT91EMAC_QUIET
1239 If this defined, the driver is quiet.
1240 The driver doen't show link status messages.
1242 CONFIG_CALXEDA_XGMAC
1243 Support for the Calxeda XGMAC device
1246 Support for SMSC's LAN91C96 chips.
1248 CONFIG_LAN91C96_BASE
1249 Define this to hold the physical address
1250 of the LAN91C96's I/O space
1252 CONFIG_LAN91C96_USE_32_BIT
1253 Define this to enable 32 bit addressing
1256 Support for SMSC's LAN91C111 chip
1258 CONFIG_SMC91111_BASE
1259 Define this to hold the physical address
1260 of the device (I/O space)
1262 CONFIG_SMC_USE_32_BIT
1263 Define this if data bus is 32 bits
1265 CONFIG_SMC_USE_IOFUNCS
1266 Define this to use i/o functions instead of macros
1267 (some hardware wont work with macros)
1269 CONFIG_DRIVER_TI_EMAC
1270 Support for davinci emac
1272 CONFIG_SYS_DAVINCI_EMAC_PHY_COUNT
1273 Define this if you have more then 3 PHYs.
1276 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1278 CONFIG_FTGMAC100_EGIGA
1279 Define this to use GE link update with gigabit PHY.
1280 Define this if FTGMAC100 is connected to gigabit PHY.
1281 If your system has 10/100 PHY only, it might not occur
1282 wrong behavior. Because PHY usually return timeout or
1283 useless data when polling gigabit status and gigabit
1284 control registers. This behavior won't affect the
1285 correctnessof 10/100 link speed update.
1288 Support for SMSC's LAN911x and LAN921x chips
1291 Define this to hold the physical address
1292 of the device (I/O space)
1294 CONFIG_SMC911X_32_BIT
1295 Define this if data bus is 32 bits
1297 CONFIG_SMC911X_16_BIT
1298 Define this if data bus is 16 bits. If your processor
1299 automatically converts one 32 bit word to two 16 bit
1300 words you may also try CONFIG_SMC911X_32_BIT.
1303 Support for Renesas on-chip Ethernet controller
1305 CONFIG_SH_ETHER_USE_PORT
1306 Define the number of ports to be used
1308 CONFIG_SH_ETHER_PHY_ADDR
1309 Define the ETH PHY's address
1311 CONFIG_SH_ETHER_CACHE_WRITEBACK
1312 If this option is set, the driver enables cache flush.
1316 Support TPM devices.
1319 Support for i2c bus TPM devices. Only one device
1320 per system is supported at this time.
1322 CONFIG_TPM_TIS_I2C_BUS_NUMBER
1323 Define the the i2c bus number for the TPM device
1325 CONFIG_TPM_TIS_I2C_SLAVE_ADDRESS
1326 Define the TPM's address on the i2c bus
1328 CONFIG_TPM_TIS_I2C_BURST_LIMITATION
1329 Define the burst count bytes upper limit
1331 CONFIG_TPM_ATMEL_TWI
1332 Support for Atmel TWI TPM device. Requires I2C support.
1335 Support for generic parallel port TPM devices. Only one device
1336 per system is supported at this time.
1338 CONFIG_TPM_TIS_BASE_ADDRESS
1339 Base address where the generic TPM device is mapped
1340 to. Contemporary x86 systems usually map it at
1344 Add tpm monitor functions.
1345 Requires CONFIG_TPM. If CONFIG_TPM_AUTH_SESSIONS is set, also
1346 provides monitor access to authorized functions.
1349 Define this to enable the TPM support library which provides
1350 functional interfaces to some TPM commands.
1351 Requires support for a TPM device.
1353 CONFIG_TPM_AUTH_SESSIONS
1354 Define this to enable authorized functions in the TPM library.
1355 Requires CONFIG_TPM and CONFIG_SHA1.
1358 At the moment only the UHCI host controller is
1359 supported (PIP405, MIP405, MPC5200); define
1360 CONFIG_USB_UHCI to enable it.
1361 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1362 and define CONFIG_USB_STORAGE to enable the USB
1365 Supported are USB Keyboards and USB Floppy drives
1367 MPC5200 USB requires additional defines:
1369 for 528 MHz Clock: 0x0001bbbb
1373 for differential drivers: 0x00001000
1374 for single ended drivers: 0x00005000
1375 for differential drivers on PSC3: 0x00000100
1376 for single ended drivers on PSC3: 0x00004100
1377 CONFIG_SYS_USB_EVENT_POLL
1378 May be defined to allow interrupt polling
1379 instead of using asynchronous interrupts
1381 CONFIG_USB_EHCI_TXFIFO_THRESH enables setting of the
1382 txfilltuning field in the EHCI controller on reset.
1384 CONFIG_USB_HUB_MIN_POWER_ON_DELAY defines the minimum
1385 interval for usb hub power-on delay.(minimum 100msec)
1388 Define the below if you wish to use the USB console.
1389 Once firmware is rebuilt from a serial console issue the
1390 command "setenv stdin usbtty; setenv stdout usbtty" and
1391 attach your USB cable. The Unix command "dmesg" should print
1392 it has found a new device. The environment variable usbtty
1393 can be set to gserial or cdc_acm to enable your device to
1394 appear to a USB host as a Linux gserial device or a
1395 Common Device Class Abstract Control Model serial device.
1396 If you select usbtty = gserial you should be able to enumerate
1398 # modprobe usbserial vendor=0xVendorID product=0xProductID
1399 else if using cdc_acm, simply setting the environment
1400 variable usbtty to be cdc_acm should suffice. The following
1401 might be defined in YourBoardName.h
1404 Define this to build a UDC device
1407 Define this to have a tty type of device available to
1408 talk to the UDC device
1411 Define this to enable the high speed support for usb
1412 device and usbtty. If this feature is enabled, a routine
1413 int is_usbd_high_speed(void)
1414 also needs to be defined by the driver to dynamically poll
1415 whether the enumeration has succeded at high speed or full
1418 CONFIG_SYS_CONSOLE_IS_IN_ENV
1419 Define this if you want stdin, stdout &/or stderr to
1423 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1424 Derive USB clock from external clock "blah"
1425 - CONFIG_SYS_USB_EXTC_CLK 0x02
1427 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1428 Derive USB clock from brgclk
1429 - CONFIG_SYS_USB_BRG_CLK 0x04
1431 If you have a USB-IF assigned VendorID then you may wish to
1432 define your own vendor specific values either in BoardName.h
1433 or directly in usbd_vendor_info.h. If you don't define
1434 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1435 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1436 should pretend to be a Linux device to it's target host.
1438 CONFIG_USBD_MANUFACTURER
1439 Define this string as the name of your company for
1440 - CONFIG_USBD_MANUFACTURER "my company"
1442 CONFIG_USBD_PRODUCT_NAME
1443 Define this string as the name of your product
1444 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1446 CONFIG_USBD_VENDORID
1447 Define this as your assigned Vendor ID from the USB
1448 Implementors Forum. This *must* be a genuine Vendor ID
1449 to avoid polluting the USB namespace.
1450 - CONFIG_USBD_VENDORID 0xFFFF
1452 CONFIG_USBD_PRODUCTID
1453 Define this as the unique Product ID
1455 - CONFIG_USBD_PRODUCTID 0xFFFF
1457 Some USB device drivers may need to check USB cable attachment.
1458 In this case you can enable following config in BoardName.h:
1459 CONFIG_USB_CABLE_CHECK
1460 This enables function definition:
1461 - usb_cable_connected() in include/usb.h
1462 Implementation of this function is board-specific.
1464 - ULPI Layer Support:
1465 The ULPI (UTMI Low Pin (count) Interface) PHYs are supported via
1466 the generic ULPI layer. The generic layer accesses the ULPI PHY
1467 via the platform viewport, so you need both the genric layer and
1468 the viewport enabled. Currently only Chipidea/ARC based
1469 viewport is supported.
1470 To enable the ULPI layer support, define CONFIG_USB_ULPI and
1471 CONFIG_USB_ULPI_VIEWPORT in your board configuration file.
1472 If your ULPI phy needs a different reference clock than the
1473 standard 24 MHz then you have to define CONFIG_ULPI_REF_CLK to
1474 the appropriate value in Hz.
1477 The MMC controller on the Intel PXA is supported. To
1478 enable this define CONFIG_MMC. The MMC can be
1479 accessed from the boot prompt by mapping the device
1480 to physical memory similar to flash. Command line is
1481 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1482 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1485 Support for Renesas on-chip MMCIF controller
1487 CONFIG_SH_MMCIF_ADDR
1488 Define the base address of MMCIF registers
1491 Define the clock frequency for MMCIF
1493 - USB Device Firmware Update (DFU) class support:
1495 This enables the USB portion of the DFU USB class
1498 This enables the command "dfu" which is used to have
1499 U-Boot create a DFU class device via USB. This command
1500 requires that the "dfu_alt_info" environment variable be
1501 set and define the alt settings to expose to the host.
1504 This enables support for exposing (e)MMC devices via DFU.
1507 This enables support for exposing NAND devices via DFU.
1510 This enables support for exposing RAM via DFU.
1511 Note: DFU spec refer to non-volatile memory usage, but
1512 allow usages beyond the scope of spec - here RAM usage,
1513 one that would help mostly the developer.
1515 CONFIG_SYS_DFU_DATA_BUF_SIZE
1516 Dfu transfer uses a buffer before writing data to the
1517 raw storage device. Make the size (in bytes) of this buffer
1518 configurable. The size of this buffer is also configurable
1519 through the "dfu_bufsiz" environment variable.
1521 CONFIG_SYS_DFU_MAX_FILE_SIZE
1522 When updating files rather than the raw storage device,
1523 we use a static buffer to copy the file into and then write
1524 the buffer once we've been given the whole file. Define
1525 this to the maximum filesize (in bytes) for the buffer.
1526 Default is 4 MiB if undefined.
1528 - Journaling Flash filesystem support:
1529 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1530 CONFIG_JFFS2_NAND_DEV
1531 Define these for a default partition on a NAND device
1533 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1534 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1535 Define these for a default partition on a NOR device
1537 CONFIG_SYS_JFFS_CUSTOM_PART
1538 Define this to create an own partition. You have to provide a
1539 function struct part_info* jffs2_part_info(int part_num)
1541 If you define only one JFFS2 partition you may also want to
1542 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1543 to disable the command chpart. This is the default when you
1544 have not defined a custom partition
1546 - FAT(File Allocation Table) filesystem write function support:
1549 Define this to enable support for saving memory data as a
1550 file in FAT formatted partition.
1552 This will also enable the command "fatwrite" enabling the
1553 user to write files to FAT.
1555 CBFS (Coreboot Filesystem) support
1558 Define this to enable support for reading from a Coreboot
1559 filesystem. Available commands are cbfsinit, cbfsinfo, cbfsls
1565 Define this to enable standard (PC-Style) keyboard
1569 Standard PC keyboard driver with US (is default) and
1570 GERMAN key layout (switch via environment 'keymap=de') support.
1571 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1572 for cfb_console. Supports cursor blinking.
1575 Enables a Chrome OS keyboard using the CROS_EC interface.
1576 This uses CROS_EC to communicate with a second microcontroller
1577 which provides key scans on request.
1582 Define this to enable video support (for output to
1585 CONFIG_VIDEO_CT69000
1587 Enable Chips & Technologies 69000 Video chip
1589 CONFIG_VIDEO_SMI_LYNXEM
1590 Enable Silicon Motion SMI 712/710/810 Video chip. The
1591 video output is selected via environment 'videoout'
1592 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1595 For the CT69000 and SMI_LYNXEM drivers, videomode is
1596 selected via environment 'videomode'. Two different ways
1598 - "videomode=num" 'num' is a standard LiLo mode numbers.
1599 Following standard modes are supported (* is default):
1601 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1602 -------------+---------------------------------------------
1603 8 bits | 0x301* 0x303 0x305 0x161 0x307
1604 15 bits | 0x310 0x313 0x316 0x162 0x319
1605 16 bits | 0x311 0x314 0x317 0x163 0x31A
1606 24 bits | 0x312 0x315 0x318 ? 0x31B
1607 -------------+---------------------------------------------
1608 (i.e. setenv videomode 317; saveenv; reset;)
1610 - "videomode=bootargs" all the video parameters are parsed
1611 from the bootargs. (See drivers/video/videomodes.c)
1614 CONFIG_VIDEO_SED13806
1615 Enable Epson SED13806 driver. This driver supports 8bpp
1616 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1617 or CONFIG_VIDEO_SED13806_16BPP
1620 Enable the Freescale DIU video driver. Reference boards for
1621 SOCs that have a DIU should define this macro to enable DIU
1622 support, and should also define these other macros:
1628 CONFIG_VIDEO_SW_CURSOR
1629 CONFIG_VGA_AS_SINGLE_DEVICE
1631 CONFIG_VIDEO_BMP_LOGO
1633 The DIU driver will look for the 'video-mode' environment
1634 variable, and if defined, enable the DIU as a console during
1635 boot. See the documentation file README.video for a
1636 description of this variable.
1640 Enable the VGA video / BIOS for x86. The alternative if you
1641 are using coreboot is to use the coreboot frame buffer
1648 Define this to enable a custom keyboard support.
1649 This simply calls drv_keyboard_init() which must be
1650 defined in your board-specific files.
1651 The only board using this so far is RBC823.
1653 - LCD Support: CONFIG_LCD
1655 Define this to enable LCD support (for output to LCD
1656 display); also select one of the supported displays
1657 by defining one of these:
1661 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1663 CONFIG_NEC_NL6448AC33:
1665 NEC NL6448AC33-18. Active, color, single scan.
1667 CONFIG_NEC_NL6448BC20
1669 NEC NL6448BC20-08. 6.5", 640x480.
1670 Active, color, single scan.
1672 CONFIG_NEC_NL6448BC33_54
1674 NEC NL6448BC33-54. 10.4", 640x480.
1675 Active, color, single scan.
1679 Sharp 320x240. Active, color, single scan.
1680 It isn't 16x9, and I am not sure what it is.
1682 CONFIG_SHARP_LQ64D341
1684 Sharp LQ64D341 display, 640x480.
1685 Active, color, single scan.
1689 HLD1045 display, 640x480.
1690 Active, color, single scan.
1694 Optrex CBL50840-2 NF-FW 99 22 M5
1696 Hitachi LMG6912RPFC-00T
1700 320x240. Black & white.
1702 Normally display is black on white background; define
1703 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1705 CONFIG_LCD_ALIGNMENT
1707 Normally the LCD is page-aligned (tyically 4KB). If this is
1708 defined then the LCD will be aligned to this value instead.
1709 For ARM it is sometimes useful to use MMU_SECTION_SIZE
1710 here, since it is cheaper to change data cache settings on
1711 a per-section basis.
1713 CONFIG_CONSOLE_SCROLL_LINES
1715 When the console need to be scrolled, this is the number of
1716 lines to scroll by. It defaults to 1. Increasing this makes
1717 the console jump but can help speed up operation when scrolling
1722 Support drawing of RLE8-compressed bitmaps on the LCD.
1726 Enables an 'i2c edid' command which can read EDID
1727 information over I2C from an attached LCD display.
1729 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1731 If this option is set, the environment is checked for
1732 a variable "splashimage". If found, the usual display
1733 of logo, copyright and system information on the LCD
1734 is suppressed and the BMP image at the address
1735 specified in "splashimage" is loaded instead. The
1736 console is redirected to the "nulldev", too. This
1737 allows for a "silent" boot where a splash screen is
1738 loaded very quickly after power-on.
1740 CONFIG_SPLASHIMAGE_GUARD
1742 If this option is set, then U-Boot will prevent the environment
1743 variable "splashimage" from being set to a problematic address
1744 (see README.displaying-bmps).
1745 This option is useful for targets where, due to alignment
1746 restrictions, an improperly aligned BMP image will cause a data
1747 abort. If you think you will not have problems with unaligned
1748 accesses (for example because your toolchain prevents them)
1749 there is no need to set this option.
1751 CONFIG_SPLASH_SCREEN_ALIGN
1753 If this option is set the splash image can be freely positioned
1754 on the screen. Environment variable "splashpos" specifies the
1755 position as "x,y". If a positive number is given it is used as
1756 number of pixel from left/top. If a negative number is given it
1757 is used as number of pixel from right/bottom. You can also
1758 specify 'm' for centering the image.
1761 setenv splashpos m,m
1762 => image at center of screen
1764 setenv splashpos 30,20
1765 => image at x = 30 and y = 20
1767 setenv splashpos -10,m
1768 => vertically centered image
1769 at x = dspWidth - bmpWidth - 9
1771 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1773 If this option is set, additionally to standard BMP
1774 images, gzipped BMP images can be displayed via the
1775 splashscreen support or the bmp command.
1777 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1779 If this option is set, 8-bit RLE compressed BMP images
1780 can be displayed via the splashscreen support or the
1783 - Do compresssing for memory range:
1786 If this option is set, it would use zlib deflate method
1787 to compress the specified memory at its best effort.
1789 - Compression support:
1792 Enabled by default to support gzip compressed images.
1796 If this option is set, support for bzip2 compressed
1797 images is included. If not, only uncompressed and gzip
1798 compressed images are supported.
1800 NOTE: the bzip2 algorithm requires a lot of RAM, so
1801 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1806 If this option is set, support for lzma compressed
1809 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1810 requires an amount of dynamic memory that is given by the
1813 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1815 Where lc and lp stand for, respectively, Literal context bits
1816 and Literal pos bits.
1818 This value is upper-bounded by 14MB in the worst case. Anyway,
1819 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1820 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1821 a very small buffer.
1823 Use the lzmainfo tool to determinate the lc and lp values and
1824 then calculate the amount of needed dynamic memory (ensuring
1825 the appropriate CONFIG_SYS_MALLOC_LEN value).
1829 If this option is set, support for LZO compressed images
1835 The address of PHY on MII bus.
1837 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1839 The clock frequency of the MII bus
1843 If this option is set, support for speed/duplex
1844 detection of gigabit PHY is included.
1846 CONFIG_PHY_RESET_DELAY
1848 Some PHY like Intel LXT971A need extra delay after
1849 reset before any MII register access is possible.
1850 For such PHY, set this option to the usec delay
1851 required. (minimum 300usec for LXT971A)
1853 CONFIG_PHY_CMD_DELAY (ppc4xx)
1855 Some PHY like Intel LXT971A need extra delay after
1856 command issued before MII status register can be read
1866 Define a default value for Ethernet address to use
1867 for the respective Ethernet interface, in case this
1868 is not determined automatically.
1873 Define a default value for the IP address to use for
1874 the default Ethernet interface, in case this is not
1875 determined through e.g. bootp.
1876 (Environment variable "ipaddr")
1878 - Server IP address:
1881 Defines a default value for the IP address of a TFTP
1882 server to contact when using the "tftboot" command.
1883 (Environment variable "serverip")
1885 CONFIG_KEEP_SERVERADDR
1887 Keeps the server's MAC address, in the env 'serveraddr'
1888 for passing to bootargs (like Linux's netconsole option)
1890 - Gateway IP address:
1893 Defines a default value for the IP address of the
1894 default router where packets to other networks are
1896 (Environment variable "gatewayip")
1901 Defines a default value for the subnet mask (or
1902 routing prefix) which is used to determine if an IP
1903 address belongs to the local subnet or needs to be
1904 forwarded through a router.
1905 (Environment variable "netmask")
1907 - Multicast TFTP Mode:
1910 Defines whether you want to support multicast TFTP as per
1911 rfc-2090; for example to work with atftp. Lets lots of targets
1912 tftp down the same boot image concurrently. Note: the Ethernet
1913 driver in use must provide a function: mcast() to join/leave a
1916 - BOOTP Recovery Mode:
1917 CONFIG_BOOTP_RANDOM_DELAY
1919 If you have many targets in a network that try to
1920 boot using BOOTP, you may want to avoid that all
1921 systems send out BOOTP requests at precisely the same
1922 moment (which would happen for instance at recovery
1923 from a power failure, when all systems will try to
1924 boot, thus flooding the BOOTP server. Defining
1925 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1926 inserted before sending out BOOTP requests. The
1927 following delays are inserted then:
1929 1st BOOTP request: delay 0 ... 1 sec
1930 2nd BOOTP request: delay 0 ... 2 sec
1931 3rd BOOTP request: delay 0 ... 4 sec
1933 BOOTP requests: delay 0 ... 8 sec
1935 - DHCP Advanced Options:
1936 You can fine tune the DHCP functionality by defining
1937 CONFIG_BOOTP_* symbols:
1939 CONFIG_BOOTP_SUBNETMASK
1940 CONFIG_BOOTP_GATEWAY
1941 CONFIG_BOOTP_HOSTNAME
1942 CONFIG_BOOTP_NISDOMAIN
1943 CONFIG_BOOTP_BOOTPATH
1944 CONFIG_BOOTP_BOOTFILESIZE
1947 CONFIG_BOOTP_SEND_HOSTNAME
1948 CONFIG_BOOTP_NTPSERVER
1949 CONFIG_BOOTP_TIMEOFFSET
1950 CONFIG_BOOTP_VENDOREX
1951 CONFIG_BOOTP_MAY_FAIL
1953 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1954 environment variable, not the BOOTP server.
1956 CONFIG_BOOTP_MAY_FAIL - If the DHCP server is not found
1957 after the configured retry count, the call will fail
1958 instead of starting over. This can be used to fail over
1959 to Link-local IP address configuration if the DHCP server
1962 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1963 serverip from a DHCP server, it is possible that more
1964 than one DNS serverip is offered to the client.
1965 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1966 serverip will be stored in the additional environment
1967 variable "dnsip2". The first DNS serverip is always
1968 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1971 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1972 to do a dynamic update of a DNS server. To do this, they
1973 need the hostname of the DHCP requester.
1974 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1975 of the "hostname" environment variable is passed as
1976 option 12 to the DHCP server.
1978 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1980 A 32bit value in microseconds for a delay between
1981 receiving a "DHCP Offer" and sending the "DHCP Request".
1982 This fixes a problem with certain DHCP servers that don't
1983 respond 100% of the time to a "DHCP request". E.g. On an
1984 AT91RM9200 processor running at 180MHz, this delay needed
1985 to be *at least* 15,000 usec before a Windows Server 2003
1986 DHCP server would reply 100% of the time. I recommend at
1987 least 50,000 usec to be safe. The alternative is to hope
1988 that one of the retries will be successful but note that
1989 the DHCP timeout and retry process takes a longer than
1992 - Link-local IP address negotiation:
1993 Negotiate with other link-local clients on the local network
1994 for an address that doesn't require explicit configuration.
1995 This is especially useful if a DHCP server cannot be guaranteed
1996 to exist in all environments that the device must operate.
1998 See doc/README.link-local for more information.
2001 CONFIG_CDP_DEVICE_ID
2003 The device id used in CDP trigger frames.
2005 CONFIG_CDP_DEVICE_ID_PREFIX
2007 A two character string which is prefixed to the MAC address
2012 A printf format string which contains the ascii name of
2013 the port. Normally is set to "eth%d" which sets
2014 eth0 for the first Ethernet, eth1 for the second etc.
2016 CONFIG_CDP_CAPABILITIES
2018 A 32bit integer which indicates the device capabilities;
2019 0x00000010 for a normal host which does not forwards.
2023 An ascii string containing the version of the software.
2027 An ascii string containing the name of the platform.
2031 A 32bit integer sent on the trigger.
2033 CONFIG_CDP_POWER_CONSUMPTION
2035 A 16bit integer containing the power consumption of the
2036 device in .1 of milliwatts.
2038 CONFIG_CDP_APPLIANCE_VLAN_TYPE
2040 A byte containing the id of the VLAN.
2042 - Status LED: CONFIG_STATUS_LED
2044 Several configurations allow to display the current
2045 status using a LED. For instance, the LED will blink
2046 fast while running U-Boot code, stop blinking as
2047 soon as a reply to a BOOTP request was received, and
2048 start blinking slow once the Linux kernel is running
2049 (supported by a status LED driver in the Linux
2050 kernel). Defining CONFIG_STATUS_LED enables this
2056 The status LED can be connected to a GPIO pin.
2057 In such cases, the gpio_led driver can be used as a
2058 status LED backend implementation. Define CONFIG_GPIO_LED
2059 to include the gpio_led driver in the U-Boot binary.
2061 CONFIG_GPIO_LED_INVERTED_TABLE
2062 Some GPIO connected LEDs may have inverted polarity in which
2063 case the GPIO high value corresponds to LED off state and
2064 GPIO low value corresponds to LED on state.
2065 In such cases CONFIG_GPIO_LED_INVERTED_TABLE may be defined
2066 with a list of GPIO LEDs that have inverted polarity.
2068 - CAN Support: CONFIG_CAN_DRIVER
2070 Defining CONFIG_CAN_DRIVER enables CAN driver support
2071 on those systems that support this (optional)
2072 feature, like the TQM8xxL modules.
2074 - I2C Support: CONFIG_SYS_I2C
2076 This enable the NEW i2c subsystem, and will allow you to use
2077 i2c commands at the u-boot command line (as long as you set
2078 CONFIG_CMD_I2C in CONFIG_COMMANDS) and communicate with i2c
2079 based realtime clock chips or other i2c devices. See
2080 common/cmd_i2c.c for a description of the command line
2083 ported i2c driver to the new framework:
2084 - drivers/i2c/soft_i2c.c:
2085 - activate first bus with CONFIG_SYS_I2C_SOFT define
2086 CONFIG_SYS_I2C_SOFT_SPEED and CONFIG_SYS_I2C_SOFT_SLAVE
2087 for defining speed and slave address
2088 - activate second bus with I2C_SOFT_DECLARATIONS2 define
2089 CONFIG_SYS_I2C_SOFT_SPEED_2 and CONFIG_SYS_I2C_SOFT_SLAVE_2
2090 for defining speed and slave address
2091 - activate third bus with I2C_SOFT_DECLARATIONS3 define
2092 CONFIG_SYS_I2C_SOFT_SPEED_3 and CONFIG_SYS_I2C_SOFT_SLAVE_3
2093 for defining speed and slave address
2094 - activate fourth bus with I2C_SOFT_DECLARATIONS4 define
2095 CONFIG_SYS_I2C_SOFT_SPEED_4 and CONFIG_SYS_I2C_SOFT_SLAVE_4
2096 for defining speed and slave address
2098 - drivers/i2c/fsl_i2c.c:
2099 - activate i2c driver with CONFIG_SYS_I2C_FSL
2100 define CONFIG_SYS_FSL_I2C_OFFSET for setting the register
2101 offset CONFIG_SYS_FSL_I2C_SPEED for the i2c speed and
2102 CONFIG_SYS_FSL_I2C_SLAVE for the slave addr of the first
2104 - If your board supports a second fsl i2c bus, define
2105 CONFIG_SYS_FSL_I2C2_OFFSET for the register offset
2106 CONFIG_SYS_FSL_I2C2_SPEED for the speed and
2107 CONFIG_SYS_FSL_I2C2_SLAVE for the slave address of the
2110 - drivers/i2c/tegra_i2c.c:
2111 - activate this driver with CONFIG_SYS_I2C_TEGRA
2112 - This driver adds 4 i2c buses with a fix speed from
2113 100000 and the slave addr 0!
2115 - drivers/i2c/ppc4xx_i2c.c
2116 - activate this driver with CONFIG_SYS_I2C_PPC4XX
2117 - CONFIG_SYS_I2C_PPC4XX_CH0 activate hardware channel 0
2118 - CONFIG_SYS_I2C_PPC4XX_CH1 activate hardware channel 1
2120 - drivers/i2c/i2c_mxc.c
2121 - activate this driver with CONFIG_SYS_I2C_MXC
2122 - define speed for bus 1 with CONFIG_SYS_MXC_I2C1_SPEED
2123 - define slave for bus 1 with CONFIG_SYS_MXC_I2C1_SLAVE
2124 - define speed for bus 2 with CONFIG_SYS_MXC_I2C2_SPEED
2125 - define slave for bus 2 with CONFIG_SYS_MXC_I2C2_SLAVE
2126 - define speed for bus 3 with CONFIG_SYS_MXC_I2C3_SPEED
2127 - define slave for bus 3 with CONFIG_SYS_MXC_I2C3_SLAVE
2128 If thoses defines are not set, default value is 100000
2129 for speed, and 0 for slave.
2131 - drivers/i2c/rcar_i2c.c:
2132 - activate this driver with CONFIG_SYS_I2C_RCAR
2133 - This driver adds 4 i2c buses
2135 - CONFIG_SYS_RCAR_I2C0_BASE for setting the register channel 0
2136 - CONFIG_SYS_RCAR_I2C0_SPEED for for the speed channel 0
2137 - CONFIG_SYS_RCAR_I2C1_BASE for setting the register channel 1
2138 - CONFIG_SYS_RCAR_I2C1_SPEED for for the speed channel 1
2139 - CONFIG_SYS_RCAR_I2C2_BASE for setting the register channel 2
2140 - CONFIG_SYS_RCAR_I2C2_SPEED for for the speed channel 2
2141 - CONFIG_SYS_RCAR_I2C3_BASE for setting the register channel 3
2142 - CONFIG_SYS_RCAR_I2C3_SPEED for for the speed channel 3
2143 - CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS for number of i2c buses
2145 - drivers/i2c/sh_i2c.c:
2146 - activate this driver with CONFIG_SYS_I2C_SH
2147 - This driver adds from 2 to 5 i2c buses
2149 - CONFIG_SYS_I2C_SH_BASE0 for setting the register channel 0
2150 - CONFIG_SYS_I2C_SH_SPEED0 for for the speed channel 0
2151 - CONFIG_SYS_I2C_SH_BASE1 for setting the register channel 1
2152 - CONFIG_SYS_I2C_SH_SPEED1 for for the speed channel 1
2153 - CONFIG_SYS_I2C_SH_BASE2 for setting the register channel 2
2154 - CONFIG_SYS_I2C_SH_SPEED2 for for the speed channel 2
2155 - CONFIG_SYS_I2C_SH_BASE3 for setting the register channel 3
2156 - CONFIG_SYS_I2C_SH_SPEED3 for for the speed channel 3
2157 - CONFIG_SYS_I2C_SH_BASE4 for setting the register channel 4
2158 - CONFIG_SYS_I2C_SH_SPEED4 for for the speed channel 4
2159 - CONFIG_SYS_I2C_SH_BASE5 for setting the register channel 5
2160 - CONFIG_SYS_I2C_SH_SPEED5 for for the speed channel 5
2161 - CONFIF_SYS_I2C_SH_NUM_CONTROLLERS for nummber of i2c buses
2163 - drivers/i2c/omap24xx_i2c.c
2164 - activate this driver with CONFIG_SYS_I2C_OMAP24XX
2165 - CONFIG_SYS_OMAP24_I2C_SPEED speed channel 0
2166 - CONFIG_SYS_OMAP24_I2C_SLAVE slave addr channel 0
2167 - CONFIG_SYS_OMAP24_I2C_SPEED1 speed channel 1
2168 - CONFIG_SYS_OMAP24_I2C_SLAVE1 slave addr channel 1
2169 - CONFIG_SYS_OMAP24_I2C_SPEED2 speed channel 2
2170 - CONFIG_SYS_OMAP24_I2C_SLAVE2 slave addr channel 2
2171 - CONFIG_SYS_OMAP24_I2C_SPEED3 speed channel 3
2172 - CONFIG_SYS_OMAP24_I2C_SLAVE3 slave addr channel 3
2173 - CONFIG_SYS_OMAP24_I2C_SPEED4 speed channel 4
2174 - CONFIG_SYS_OMAP24_I2C_SLAVE4 slave addr channel 4
2176 - drivers/i2c/zynq_i2c.c
2177 - activate this driver with CONFIG_SYS_I2C_ZYNQ
2178 - set CONFIG_SYS_I2C_ZYNQ_SPEED for speed setting
2179 - set CONFIG_SYS_I2C_ZYNQ_SLAVE for slave addr
2181 - drivers/i2c/s3c24x0_i2c.c:
2182 - activate this driver with CONFIG_SYS_I2C_S3C24X0
2183 - This driver adds i2c buses (11 for Exynos5250, Exynos5420
2184 9 i2c buses for Exynos4 and 1 for S3C24X0 SoCs from Samsung)
2185 with a fix speed from 100000 and the slave addr 0!
2189 CONFIG_SYS_NUM_I2C_BUSES
2190 Hold the number of i2c busses you want to use. If you
2191 don't use/have i2c muxes on your i2c bus, this
2192 is equal to CONFIG_SYS_NUM_I2C_ADAPTERS, and you can
2195 CONFIG_SYS_I2C_DIRECT_BUS
2196 define this, if you don't use i2c muxes on your hardware.
2197 if CONFIG_SYS_I2C_MAX_HOPS is not defined or == 0 you can
2200 CONFIG_SYS_I2C_MAX_HOPS
2201 define how many muxes are maximal consecutively connected
2202 on one i2c bus. If you not use i2c muxes, omit this
2205 CONFIG_SYS_I2C_BUSES
2206 hold a list of busses you want to use, only used if
2207 CONFIG_SYS_I2C_DIRECT_BUS is not defined, for example
2208 a board with CONFIG_SYS_I2C_MAX_HOPS = 1 and
2209 CONFIG_SYS_NUM_I2C_BUSES = 9:
2211 CONFIG_SYS_I2C_BUSES {{0, {I2C_NULL_HOP}}, \
2212 {0, {{I2C_MUX_PCA9547, 0x70, 1}}}, \
2213 {0, {{I2C_MUX_PCA9547, 0x70, 2}}}, \
2214 {0, {{I2C_MUX_PCA9547, 0x70, 3}}}, \
2215 {0, {{I2C_MUX_PCA9547, 0x70, 4}}}, \
2216 {0, {{I2C_MUX_PCA9547, 0x70, 5}}}, \
2217 {1, {I2C_NULL_HOP}}, \
2218 {1, {{I2C_MUX_PCA9544, 0x72, 1}}}, \
2219 {1, {{I2C_MUX_PCA9544, 0x72, 2}}}, \
2223 bus 0 on adapter 0 without a mux
2224 bus 1 on adapter 0 with a PCA9547 on address 0x70 port 1
2225 bus 2 on adapter 0 with a PCA9547 on address 0x70 port 2
2226 bus 3 on adapter 0 with a PCA9547 on address 0x70 port 3
2227 bus 4 on adapter 0 with a PCA9547 on address 0x70 port 4
2228 bus 5 on adapter 0 with a PCA9547 on address 0x70 port 5
2229 bus 6 on adapter 1 without a mux
2230 bus 7 on adapter 1 with a PCA9544 on address 0x72 port 1
2231 bus 8 on adapter 1 with a PCA9544 on address 0x72 port 2
2233 If you do not have i2c muxes on your board, omit this define.
2235 - Legacy I2C Support: CONFIG_HARD_I2C
2237 NOTE: It is intended to move drivers to CONFIG_SYS_I2C which
2238 provides the following compelling advantages:
2240 - more than one i2c adapter is usable
2241 - approved multibus support
2242 - better i2c mux support
2244 ** Please consider updating your I2C driver now. **
2246 These enable legacy I2C serial bus commands. Defining
2247 CONFIG_HARD_I2C will include the appropriate I2C driver
2248 for the selected CPU.
2250 This will allow you to use i2c commands at the u-boot
2251 command line (as long as you set CONFIG_CMD_I2C in
2252 CONFIG_COMMANDS) and communicate with i2c based realtime
2253 clock chips. See common/cmd_i2c.c for a description of the
2254 command line interface.
2256 CONFIG_HARD_I2C selects a hardware I2C controller.
2258 There are several other quantities that must also be
2259 defined when you define CONFIG_HARD_I2C.
2261 In both cases you will need to define CONFIG_SYS_I2C_SPEED
2262 to be the frequency (in Hz) at which you wish your i2c bus
2263 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
2264 the CPU's i2c node address).
2266 Now, the u-boot i2c code for the mpc8xx
2267 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
2268 and so its address should therefore be cleared to 0 (See,
2269 eg, MPC823e User's Manual p.16-473). So, set
2270 CONFIG_SYS_I2C_SLAVE to 0.
2272 CONFIG_SYS_I2C_INIT_MPC5XXX
2274 When a board is reset during an i2c bus transfer
2275 chips might think that the current transfer is still
2276 in progress. Reset the slave devices by sending start
2277 commands until the slave device responds.
2279 That's all that's required for CONFIG_HARD_I2C.
2281 If you use the software i2c interface (CONFIG_SYS_I2C_SOFT)
2282 then the following macros need to be defined (examples are
2283 from include/configs/lwmon.h):
2287 (Optional). Any commands necessary to enable the I2C
2288 controller or configure ports.
2290 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
2294 (Only for MPC8260 CPU). The I/O port to use (the code
2295 assumes both bits are on the same port). Valid values
2296 are 0..3 for ports A..D.
2300 The code necessary to make the I2C data line active
2301 (driven). If the data line is open collector, this
2304 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
2308 The code necessary to make the I2C data line tri-stated
2309 (inactive). If the data line is open collector, this
2312 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
2316 Code that returns true if the I2C data line is high,
2319 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
2323 If <bit> is true, sets the I2C data line high. If it
2324 is false, it clears it (low).
2326 eg: #define I2C_SDA(bit) \
2327 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
2328 else immr->im_cpm.cp_pbdat &= ~PB_SDA
2332 If <bit> is true, sets the I2C clock line high. If it
2333 is false, it clears it (low).
2335 eg: #define I2C_SCL(bit) \
2336 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
2337 else immr->im_cpm.cp_pbdat &= ~PB_SCL
2341 This delay is invoked four times per clock cycle so this
2342 controls the rate of data transfer. The data rate thus
2343 is 1 / (I2C_DELAY * 4). Often defined to be something
2346 #define I2C_DELAY udelay(2)
2348 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
2350 If your arch supports the generic GPIO framework (asm/gpio.h),
2351 then you may alternatively define the two GPIOs that are to be
2352 used as SCL / SDA. Any of the previous I2C_xxx macros will
2353 have GPIO-based defaults assigned to them as appropriate.
2355 You should define these to the GPIO value as given directly to
2356 the generic GPIO functions.
2358 CONFIG_SYS_I2C_INIT_BOARD
2360 When a board is reset during an i2c bus transfer
2361 chips might think that the current transfer is still
2362 in progress. On some boards it is possible to access
2363 the i2c SCLK line directly, either by using the
2364 processor pin as a GPIO or by having a second pin
2365 connected to the bus. If this option is defined a
2366 custom i2c_init_board() routine in boards/xxx/board.c
2367 is run early in the boot sequence.
2369 CONFIG_SYS_I2C_BOARD_LATE_INIT
2371 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
2372 defined a custom i2c_board_late_init() routine in
2373 boards/xxx/board.c is run AFTER the operations in i2c_init()
2374 is completed. This callpoint can be used to unreset i2c bus
2375 using CPU i2c controller register accesses for CPUs whose i2c
2376 controller provide such a method. It is called at the end of
2377 i2c_init() to allow i2c_init operations to setup the i2c bus
2378 controller on the CPU (e.g. setting bus speed & slave address).
2380 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
2382 This option enables configuration of bi_iic_fast[] flags
2383 in u-boot bd_info structure based on u-boot environment
2384 variable "i2cfast". (see also i2cfast)
2386 CONFIG_I2C_MULTI_BUS
2388 This option allows the use of multiple I2C buses, each of which
2389 must have a controller. At any point in time, only one bus is
2390 active. To switch to a different bus, use the 'i2c dev' command.
2391 Note that bus numbering is zero-based.
2393 CONFIG_SYS_I2C_NOPROBES
2395 This option specifies a list of I2C devices that will be skipped
2396 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
2397 is set, specify a list of bus-device pairs. Otherwise, specify
2398 a 1D array of device addresses
2401 #undef CONFIG_I2C_MULTI_BUS
2402 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
2404 will skip addresses 0x50 and 0x68 on a board with one I2C bus
2406 #define CONFIG_I2C_MULTI_BUS
2407 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
2409 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
2411 CONFIG_SYS_SPD_BUS_NUM
2413 If defined, then this indicates the I2C bus number for DDR SPD.
2414 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
2416 CONFIG_SYS_RTC_BUS_NUM
2418 If defined, then this indicates the I2C bus number for the RTC.
2419 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
2421 CONFIG_SYS_DTT_BUS_NUM
2423 If defined, then this indicates the I2C bus number for the DTT.
2424 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
2426 CONFIG_SYS_I2C_DTT_ADDR:
2428 If defined, specifies the I2C address of the DTT device.
2429 If not defined, then U-Boot uses predefined value for
2430 specified DTT device.
2432 CONFIG_SOFT_I2C_READ_REPEATED_START
2434 defining this will force the i2c_read() function in
2435 the soft_i2c driver to perform an I2C repeated start
2436 between writing the address pointer and reading the
2437 data. If this define is omitted the default behaviour
2438 of doing a stop-start sequence will be used. Most I2C
2439 devices can use either method, but some require one or
2442 - SPI Support: CONFIG_SPI
2444 Enables SPI driver (so far only tested with
2445 SPI EEPROM, also an instance works with Crystal A/D and
2446 D/As on the SACSng board)
2450 Enables the driver for SPI controller on SuperH. Currently
2451 only SH7757 is supported.
2455 Enables extended (16-bit) SPI EEPROM addressing.
2456 (symmetrical to CONFIG_I2C_X)
2460 Enables a software (bit-bang) SPI driver rather than
2461 using hardware support. This is a general purpose
2462 driver that only requires three general I/O port pins
2463 (two outputs, one input) to function. If this is
2464 defined, the board configuration must define several
2465 SPI configuration items (port pins to use, etc). For
2466 an example, see include/configs/sacsng.h.
2470 Enables a hardware SPI driver for general-purpose reads
2471 and writes. As with CONFIG_SOFT_SPI, the board configuration
2472 must define a list of chip-select function pointers.
2473 Currently supported on some MPC8xxx processors. For an
2474 example, see include/configs/mpc8349emds.h.
2478 Enables the driver for the SPI controllers on i.MX and MXC
2479 SoCs. Currently i.MX31/35/51 are supported.
2481 - FPGA Support: CONFIG_FPGA
2483 Enables FPGA subsystem.
2485 CONFIG_FPGA_<vendor>
2487 Enables support for specific chip vendors.
2490 CONFIG_FPGA_<family>
2492 Enables support for FPGA family.
2493 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
2497 Specify the number of FPGA devices to support.
2499 CONFIG_SYS_FPGA_PROG_FEEDBACK
2501 Enable printing of hash marks during FPGA configuration.
2503 CONFIG_SYS_FPGA_CHECK_BUSY
2505 Enable checks on FPGA configuration interface busy
2506 status by the configuration function. This option
2507 will require a board or device specific function to
2512 If defined, a function that provides delays in the FPGA
2513 configuration driver.
2515 CONFIG_SYS_FPGA_CHECK_CTRLC
2516 Allow Control-C to interrupt FPGA configuration
2518 CONFIG_SYS_FPGA_CHECK_ERROR
2520 Check for configuration errors during FPGA bitfile
2521 loading. For example, abort during Virtex II
2522 configuration if the INIT_B line goes low (which
2523 indicated a CRC error).
2525 CONFIG_SYS_FPGA_WAIT_INIT
2527 Maximum time to wait for the INIT_B line to deassert
2528 after PROB_B has been deasserted during a Virtex II
2529 FPGA configuration sequence. The default time is 500
2532 CONFIG_SYS_FPGA_WAIT_BUSY
2534 Maximum time to wait for BUSY to deassert during
2535 Virtex II FPGA configuration. The default is 5 ms.
2537 CONFIG_SYS_FPGA_WAIT_CONFIG
2539 Time to wait after FPGA configuration. The default is
2542 - Configuration Management:
2545 If defined, this string will be added to the U-Boot
2546 version information (U_BOOT_VERSION)
2548 - Vendor Parameter Protection:
2550 U-Boot considers the values of the environment
2551 variables "serial#" (Board Serial Number) and
2552 "ethaddr" (Ethernet Address) to be parameters that
2553 are set once by the board vendor / manufacturer, and
2554 protects these variables from casual modification by
2555 the user. Once set, these variables are read-only,
2556 and write or delete attempts are rejected. You can
2557 change this behaviour:
2559 If CONFIG_ENV_OVERWRITE is #defined in your config
2560 file, the write protection for vendor parameters is
2561 completely disabled. Anybody can change or delete
2564 Alternatively, if you #define _both_ CONFIG_ETHADDR
2565 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
2566 Ethernet address is installed in the environment,
2567 which can be changed exactly ONCE by the user. [The
2568 serial# is unaffected by this, i. e. it remains
2571 The same can be accomplished in a more flexible way
2572 for any variable by configuring the type of access
2573 to allow for those variables in the ".flags" variable
2574 or define CONFIG_ENV_FLAGS_LIST_STATIC.
2579 Define this variable to enable the reservation of
2580 "protected RAM", i. e. RAM which is not overwritten
2581 by U-Boot. Define CONFIG_PRAM to hold the number of
2582 kB you want to reserve for pRAM. You can overwrite
2583 this default value by defining an environment
2584 variable "pram" to the number of kB you want to
2585 reserve. Note that the board info structure will
2586 still show the full amount of RAM. If pRAM is
2587 reserved, a new environment variable "mem" will
2588 automatically be defined to hold the amount of
2589 remaining RAM in a form that can be passed as boot
2590 argument to Linux, for instance like that:
2592 setenv bootargs ... mem=\${mem}
2595 This way you can tell Linux not to use this memory,
2596 either, which results in a memory region that will
2597 not be affected by reboots.
2599 *WARNING* If your board configuration uses automatic
2600 detection of the RAM size, you must make sure that
2601 this memory test is non-destructive. So far, the
2602 following board configurations are known to be
2605 IVMS8, IVML24, SPD8xx, TQM8xxL,
2606 HERMES, IP860, RPXlite, LWMON,
2609 - Access to physical memory region (> 4GB)
2610 Some basic support is provided for operations on memory not
2611 normally accessible to U-Boot - e.g. some architectures
2612 support access to more than 4GB of memory on 32-bit
2613 machines using physical address extension or similar.
2614 Define CONFIG_PHYSMEM to access this basic support, which
2615 currently only supports clearing the memory.
2620 Define this variable to stop the system in case of a
2621 fatal error, so that you have to reset it manually.
2622 This is probably NOT a good idea for an embedded
2623 system where you want the system to reboot
2624 automatically as fast as possible, but it may be
2625 useful during development since you can try to debug
2626 the conditions that lead to the situation.
2628 CONFIG_NET_RETRY_COUNT
2630 This variable defines the number of retries for
2631 network operations like ARP, RARP, TFTP, or BOOTP
2632 before giving up the operation. If not defined, a
2633 default value of 5 is used.
2637 Timeout waiting for an ARP reply in milliseconds.
2641 Timeout in milliseconds used in NFS protocol.
2642 If you encounter "ERROR: Cannot umount" in nfs command,
2643 try longer timeout such as
2644 #define CONFIG_NFS_TIMEOUT 10000UL
2646 - Command Interpreter:
2647 CONFIG_AUTO_COMPLETE
2649 Enable auto completion of commands using TAB.
2651 Note that this feature has NOT been implemented yet
2652 for the "hush" shell.
2655 CONFIG_SYS_HUSH_PARSER
2657 Define this variable to enable the "hush" shell (from
2658 Busybox) as command line interpreter, thus enabling
2659 powerful command line syntax like
2660 if...then...else...fi conditionals or `&&' and '||'
2661 constructs ("shell scripts").
2663 If undefined, you get the old, much simpler behaviour
2664 with a somewhat smaller memory footprint.
2667 CONFIG_SYS_PROMPT_HUSH_PS2
2669 This defines the secondary prompt string, which is
2670 printed when the command interpreter needs more input
2671 to complete a command. Usually "> ".
2675 In the current implementation, the local variables
2676 space and global environment variables space are
2677 separated. Local variables are those you define by
2678 simply typing `name=value'. To access a local
2679 variable later on, you have write `$name' or
2680 `${name}'; to execute the contents of a variable
2681 directly type `$name' at the command prompt.
2683 Global environment variables are those you use
2684 setenv/printenv to work with. To run a command stored
2685 in such a variable, you need to use the run command,
2686 and you must not use the '$' sign to access them.
2688 To store commands and special characters in a
2689 variable, please use double quotation marks
2690 surrounding the whole text of the variable, instead
2691 of the backslashes before semicolons and special
2694 - Commandline Editing and History:
2695 CONFIG_CMDLINE_EDITING
2697 Enable editing and History functions for interactive
2698 commandline input operations
2700 - Default Environment:
2701 CONFIG_EXTRA_ENV_SETTINGS
2703 Define this to contain any number of null terminated
2704 strings (variable = value pairs) that will be part of
2705 the default environment compiled into the boot image.
2707 For example, place something like this in your
2708 board's config file:
2710 #define CONFIG_EXTRA_ENV_SETTINGS \
2714 Warning: This method is based on knowledge about the
2715 internal format how the environment is stored by the
2716 U-Boot code. This is NOT an official, exported
2717 interface! Although it is unlikely that this format
2718 will change soon, there is no guarantee either.
2719 You better know what you are doing here.
2721 Note: overly (ab)use of the default environment is
2722 discouraged. Make sure to check other ways to preset
2723 the environment like the "source" command or the
2726 CONFIG_ENV_VARS_UBOOT_CONFIG
2728 Define this in order to add variables describing the
2729 U-Boot build configuration to the default environment.
2730 These will be named arch, cpu, board, vendor, and soc.
2732 Enabling this option will cause the following to be defined:
2740 CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
2742 Define this in order to add variables describing certain
2743 run-time determined information about the hardware to the
2744 environment. These will be named board_name, board_rev.
2746 CONFIG_DELAY_ENVIRONMENT
2748 Normally the environment is loaded when the board is
2749 intialised so that it is available to U-Boot. This inhibits
2750 that so that the environment is not available until
2751 explicitly loaded later by U-Boot code. With CONFIG_OF_CONTROL
2752 this is instead controlled by the value of
2753 /config/load-environment.
2755 - DataFlash Support:
2756 CONFIG_HAS_DATAFLASH
2758 Defining this option enables DataFlash features and
2759 allows to read/write in Dataflash via the standard
2762 - Serial Flash support
2765 Defining this option enables SPI flash commands
2766 'sf probe/read/write/erase/update'.
2768 Usage requires an initial 'probe' to define the serial
2769 flash parameters, followed by read/write/erase/update
2772 The following defaults may be provided by the platform
2773 to handle the common case when only a single serial
2774 flash is present on the system.
2776 CONFIG_SF_DEFAULT_BUS Bus identifier
2777 CONFIG_SF_DEFAULT_CS Chip-select
2778 CONFIG_SF_DEFAULT_MODE (see include/spi.h)
2779 CONFIG_SF_DEFAULT_SPEED in Hz
2783 Define this option to include a destructive SPI flash
2786 CONFIG_SPI_FLASH_BAR Ban/Extended Addr Reg
2788 Define this option to use the Bank addr/Extended addr
2789 support on SPI flashes which has size > 16Mbytes.
2791 CONFIG_SF_DUAL_FLASH Dual flash memories
2793 Define this option to use dual flash support where two flash
2794 memories can be connected with a given cs line.
2795 currently Xilinx Zynq qspi support these type of connections.
2797 - SystemACE Support:
2800 Adding this option adds support for Xilinx SystemACE
2801 chips attached via some sort of local bus. The address
2802 of the chip must also be defined in the
2803 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2805 #define CONFIG_SYSTEMACE
2806 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2808 When SystemACE support is added, the "ace" device type
2809 becomes available to the fat commands, i.e. fatls.
2811 - TFTP Fixed UDP Port:
2814 If this is defined, the environment variable tftpsrcp
2815 is used to supply the TFTP UDP source port value.
2816 If tftpsrcp isn't defined, the normal pseudo-random port
2817 number generator is used.
2819 Also, the environment variable tftpdstp is used to supply
2820 the TFTP UDP destination port value. If tftpdstp isn't
2821 defined, the normal port 69 is used.
2823 The purpose for tftpsrcp is to allow a TFTP server to
2824 blindly start the TFTP transfer using the pre-configured
2825 target IP address and UDP port. This has the effect of
2826 "punching through" the (Windows XP) firewall, allowing
2827 the remainder of the TFTP transfer to proceed normally.
2828 A better solution is to properly configure the firewall,
2829 but sometimes that is not allowed.
2834 This enables a generic 'hash' command which can produce
2835 hashes / digests from a few algorithms (e.g. SHA1, SHA256).
2839 Enable the hash verify command (hash -v). This adds to code
2842 CONFIG_SHA1 - support SHA1 hashing
2843 CONFIG_SHA256 - support SHA256 hashing
2845 Note: There is also a sha1sum command, which should perhaps
2846 be deprecated in favour of 'hash sha1'.
2848 - Freescale i.MX specific commands:
2849 CONFIG_CMD_HDMIDETECT
2850 This enables 'hdmidet' command which returns true if an
2851 HDMI monitor is detected. This command is i.MX 6 specific.
2854 This enables the 'bmode' (bootmode) command for forcing
2855 a boot from specific media.
2857 This is useful for forcing the ROM's usb downloader to
2858 activate upon a watchdog reset which is nice when iterating
2859 on U-Boot. Using the reset button or running bmode normal
2860 will set it back to normal. This command currently
2861 supports i.MX53 and i.MX6.
2866 This enables the RSA algorithm used for FIT image verification
2867 in U-Boot. See doc/uImage.FIT/signature.txt for more information.
2869 The signing part is build into mkimage regardless of this
2872 - bootcount support:
2873 CONFIG_BOOTCOUNT_LIMIT
2875 This enables the bootcounter support, see:
2876 http://www.denx.de/wiki/DULG/UBootBootCountLimit
2879 enable special bootcounter support on at91sam9xe based boards.
2881 enable special bootcounter support on blackfin based boards.
2883 enable special bootcounter support on da850 based boards.
2884 CONFIG_BOOTCOUNT_RAM
2885 enable support for the bootcounter in RAM
2886 CONFIG_BOOTCOUNT_I2C
2887 enable support for the bootcounter on an i2c (like RTC) device.
2888 CONFIG_SYS_I2C_RTC_ADDR = i2c chip address
2889 CONFIG_SYS_BOOTCOUNT_ADDR = i2c addr which is used for
2891 CONFIG_BOOTCOUNT_ALEN = address len
2893 - Show boot progress:
2894 CONFIG_SHOW_BOOT_PROGRESS
2896 Defining this option allows to add some board-
2897 specific code (calling a user-provided function
2898 "show_boot_progress(int)") that enables you to show
2899 the system's boot progress on some display (for
2900 example, some LED's) on your board. At the moment,
2901 the following checkpoints are implemented:
2903 - Detailed boot stage timing
2905 Define this option to get detailed timing of each stage
2906 of the boot process.
2908 CONFIG_BOOTSTAGE_USER_COUNT
2909 This is the number of available user bootstage records.
2910 Each time you call bootstage_mark(BOOTSTAGE_ID_ALLOC, ...)
2911 a new ID will be allocated from this stash. If you exceed
2912 the limit, recording will stop.
2914 CONFIG_BOOTSTAGE_REPORT
2915 Define this to print a report before boot, similar to this:
2917 Timer summary in microseconds:
2920 3,575,678 3,575,678 board_init_f start
2921 3,575,695 17 arch_cpu_init A9
2922 3,575,777 82 arch_cpu_init done
2923 3,659,598 83,821 board_init_r start
2924 3,910,375 250,777 main_loop
2925 29,916,167 26,005,792 bootm_start
2926 30,361,327 445,160 start_kernel
2928 CONFIG_CMD_BOOTSTAGE
2929 Add a 'bootstage' command which supports printing a report
2930 and un/stashing of bootstage data.
2932 CONFIG_BOOTSTAGE_FDT
2933 Stash the bootstage information in the FDT. A root 'bootstage'
2934 node is created with each bootstage id as a child. Each child
2935 has a 'name' property and either 'mark' containing the
2936 mark time in microsecond, or 'accum' containing the
2937 accumulated time for that bootstage id in microseconds.
2942 name = "board_init_f";
2951 Code in the Linux kernel can find this in /proc/devicetree.
2953 Legacy uImage format:
2956 1 common/cmd_bootm.c before attempting to boot an image
2957 -1 common/cmd_bootm.c Image header has bad magic number
2958 2 common/cmd_bootm.c Image header has correct magic number
2959 -2 common/cmd_bootm.c Image header has bad checksum
2960 3 common/cmd_bootm.c Image header has correct checksum
2961 -3 common/cmd_bootm.c Image data has bad checksum
2962 4 common/cmd_bootm.c Image data has correct checksum
2963 -4 common/cmd_bootm.c Image is for unsupported architecture
2964 5 common/cmd_bootm.c Architecture check OK
2965 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2966 6 common/cmd_bootm.c Image Type check OK
2967 -6 common/cmd_bootm.c gunzip uncompression error
2968 -7 common/cmd_bootm.c Unimplemented compression type
2969 7 common/cmd_bootm.c Uncompression OK
2970 8 common/cmd_bootm.c No uncompress/copy overwrite error
2971 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2973 9 common/image.c Start initial ramdisk verification
2974 -10 common/image.c Ramdisk header has bad magic number
2975 -11 common/image.c Ramdisk header has bad checksum
2976 10 common/image.c Ramdisk header is OK
2977 -12 common/image.c Ramdisk data has bad checksum
2978 11 common/image.c Ramdisk data has correct checksum
2979 12 common/image.c Ramdisk verification complete, start loading
2980 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2981 13 common/image.c Start multifile image verification
2982 14 common/image.c No initial ramdisk, no multifile, continue.
2984 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2986 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2987 -31 post/post.c POST test failed, detected by post_output_backlog()
2988 -32 post/post.c POST test failed, detected by post_run_single()
2990 34 common/cmd_doc.c before loading a Image from a DOC device
2991 -35 common/cmd_doc.c Bad usage of "doc" command
2992 35 common/cmd_doc.c correct usage of "doc" command
2993 -36 common/cmd_doc.c No boot device
2994 36 common/cmd_doc.c correct boot device
2995 -37 common/cmd_doc.c Unknown Chip ID on boot device
2996 37 common/cmd_doc.c correct chip ID found, device available
2997 -38 common/cmd_doc.c Read Error on boot device
2998 38 common/cmd_doc.c reading Image header from DOC device OK
2999 -39 common/cmd_doc.c Image header has bad magic number
3000 39 common/cmd_doc.c Image header has correct magic number
3001 -40 common/cmd_doc.c Error reading Image from DOC device
3002 40 common/cmd_doc.c Image header has correct magic number
3003 41 common/cmd_ide.c before loading a Image from a IDE device
3004 -42 common/cmd_ide.c Bad usage of "ide" command
3005 42 common/cmd_ide.c correct usage of "ide" command
3006 -43 common/cmd_ide.c No boot device
3007 43 common/cmd_ide.c boot device found
3008 -44 common/cmd_ide.c Device not available
3009 44 common/cmd_ide.c Device available
3010 -45 common/cmd_ide.c wrong partition selected
3011 45 common/cmd_ide.c partition selected
3012 -46 common/cmd_ide.c Unknown partition table
3013 46 common/cmd_ide.c valid partition table found
3014 -47 common/cmd_ide.c Invalid partition type
3015 47 common/cmd_ide.c correct partition type
3016 -48 common/cmd_ide.c Error reading Image Header on boot device
3017 48 common/cmd_ide.c reading Image Header from IDE device OK
3018 -49 common/cmd_ide.c Image header has bad magic number
3019 49 common/cmd_ide.c Image header has correct magic number
3020 -50 common/cmd_ide.c Image header has bad checksum
3021 50 common/cmd_ide.c Image header has correct checksum
3022 -51 common/cmd_ide.c Error reading Image from IDE device
3023 51 common/cmd_ide.c reading Image from IDE device OK
3024 52 common/cmd_nand.c before loading a Image from a NAND device
3025 -53 common/cmd_nand.c Bad usage of "nand" command
3026 53 common/cmd_nand.c correct usage of "nand" command
3027 -54 common/cmd_nand.c No boot device
3028 54 common/cmd_nand.c boot device found
3029 -55 common/cmd_nand.c Unknown Chip ID on boot device
3030 55 common/cmd_nand.c correct chip ID found, device available
3031 -56 common/cmd_nand.c Error reading Image Header on boot device
3032 56 common/cmd_nand.c reading Image Header from NAND device OK
3033 -57 common/cmd_nand.c Image header has bad magic number
3034 57 common/cmd_nand.c Image header has correct magic number
3035 -58 common/cmd_nand.c Error reading Image from NAND device
3036 58 common/cmd_nand.c reading Image from NAND device OK
3038 -60 common/env_common.c Environment has a bad CRC, using default
3040 64 net/eth.c starting with Ethernet configuration.
3041 -64 net/eth.c no Ethernet found.
3042 65 net/eth.c Ethernet found.
3044 -80 common/cmd_net.c usage wrong
3045 80 common/cmd_net.c before calling NetLoop()
3046 -81 common/cmd_net.c some error in NetLoop() occurred
3047 81 common/cmd_net.c NetLoop() back without error
3048 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
3049 82 common/cmd_net.c trying automatic boot
3050 83 common/cmd_net.c running "source" command
3051 -83 common/cmd_net.c some error in automatic boot or "source" command
3052 84 common/cmd_net.c end without errors
3057 100 common/cmd_bootm.c Kernel FIT Image has correct format
3058 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
3059 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
3060 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
3061 102 common/cmd_bootm.c Kernel unit name specified
3062 -103 common/cmd_bootm.c Can't get kernel subimage node offset
3063 103 common/cmd_bootm.c Found configuration node
3064 104 common/cmd_bootm.c Got kernel subimage node offset
3065 -104 common/cmd_bootm.c Kernel subimage hash verification failed
3066 105 common/cmd_bootm.c Kernel subimage hash verification OK
3067 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
3068 106 common/cmd_bootm.c Architecture check OK
3069 -106 common/cmd_bootm.c Kernel subimage has wrong type
3070 107 common/cmd_bootm.c Kernel subimage type OK
3071 -107 common/cmd_bootm.c Can't get kernel subimage data/size
3072 108 common/cmd_bootm.c Got kernel subimage data/size
3073 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
3074 -109 common/cmd_bootm.c Can't get kernel subimage type
3075 -110 common/cmd_bootm.c Can't get kernel subimage comp
3076 -111 common/cmd_bootm.c Can't get kernel subimage os
3077 -112 common/cmd_bootm.c Can't get kernel subimage load address
3078 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
3080 120 common/image.c Start initial ramdisk verification
3081 -120 common/image.c Ramdisk FIT image has incorrect format
3082 121 common/image.c Ramdisk FIT image has correct format
3083 122 common/image.c No ramdisk subimage unit name, using configuration
3084 -122 common/image.c Can't get configuration for ramdisk subimage
3085 123 common/image.c Ramdisk unit name specified
3086 -124 common/image.c Can't get ramdisk subimage node offset
3087 125 common/image.c Got ramdisk subimage node offset
3088 -125 common/image.c Ramdisk subimage hash verification failed
3089 126 common/image.c Ramdisk subimage hash verification OK
3090 -126 common/image.c Ramdisk subimage for unsupported architecture
3091 127 common/image.c Architecture check OK
3092 -127 common/image.c Can't get ramdisk subimage data/size
3093 128 common/image.c Got ramdisk subimage data/size
3094 129 common/image.c Can't get ramdisk load address
3095 -129 common/image.c Got ramdisk load address
3097 -130 common/cmd_doc.c Incorrect FIT image format
3098 131 common/cmd_doc.c FIT image format OK
3100 -140 common/cmd_ide.c Incorrect FIT image format
3101 141 common/cmd_ide.c FIT image format OK
3103 -150 common/cmd_nand.c Incorrect FIT image format
3104 151 common/cmd_nand.c FIT image format OK
3106 - FIT image support:
3108 Enable support for the FIT uImage format.
3110 CONFIG_FIT_BEST_MATCH
3111 When no configuration is explicitly selected, default to the
3112 one whose fdt's compatibility field best matches that of
3113 U-Boot itself. A match is considered "best" if it matches the
3114 most specific compatibility entry of U-Boot's fdt's root node.
3115 The order of entries in the configuration's fdt is ignored.
3117 CONFIG_FIT_SIGNATURE
3118 This option enables signature verification of FIT uImages,
3119 using a hash signed and verified using RSA. See
3120 doc/uImage.FIT/signature.txt for more details.
3122 - Standalone program support:
3123 CONFIG_STANDALONE_LOAD_ADDR
3125 This option defines a board specific value for the
3126 address where standalone program gets loaded, thus
3127 overwriting the architecture dependent default
3130 - Frame Buffer Address:
3133 Define CONFIG_FB_ADDR if you want to use specific
3134 address for frame buffer. This is typically the case
3135 when using a graphics controller has separate video
3136 memory. U-Boot will then place the frame buffer at
3137 the given address instead of dynamically reserving it
3138 in system RAM by calling lcd_setmem(), which grabs
3139 the memory for the frame buffer depending on the
3140 configured panel size.
3142 Please see board_init_f function.
3144 - Automatic software updates via TFTP server
3146 CONFIG_UPDATE_TFTP_CNT_MAX
3147 CONFIG_UPDATE_TFTP_MSEC_MAX
3149 These options enable and control the auto-update feature;
3150 for a more detailed description refer to doc/README.update.
3152 - MTD Support (mtdparts command, UBI support)
3155 Adds the MTD device infrastructure from the Linux kernel.
3156 Needed for mtdparts command support.
3158 CONFIG_MTD_PARTITIONS
3160 Adds the MTD partitioning infrastructure from the Linux
3161 kernel. Needed for UBI support.
3166 Adds commands for interacting with MTD partitions formatted
3167 with the UBI flash translation layer
3169 Requires also defining CONFIG_RBTREE
3171 CONFIG_UBI_SILENCE_MSG
3173 Make the verbose messages from UBI stop printing. This leaves
3174 warnings and errors enabled.
3179 Adds commands for interacting with UBI volumes formatted as
3180 UBIFS. UBIFS is read-only in u-boot.
3182 Requires UBI support as well as CONFIG_LZO
3184 CONFIG_UBIFS_SILENCE_MSG
3186 Make the verbose messages from UBIFS stop printing. This leaves
3187 warnings and errors enabled.
3191 Enable building of SPL globally.
3194 LDSCRIPT for linking the SPL binary.
3196 CONFIG_SPL_MAX_FOOTPRINT
3197 Maximum size in memory allocated to the SPL, BSS included.
3198 When defined, the linker checks that the actual memory
3199 used by SPL from _start to __bss_end does not exceed it.
3200 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3201 must not be both defined at the same time.
3204 Maximum size of the SPL image (text, data, rodata, and
3205 linker lists sections), BSS excluded.
3206 When defined, the linker checks that the actual size does
3209 CONFIG_SPL_TEXT_BASE
3210 TEXT_BASE for linking the SPL binary.
3212 CONFIG_SPL_RELOC_TEXT_BASE
3213 Address to relocate to. If unspecified, this is equal to
3214 CONFIG_SPL_TEXT_BASE (i.e. no relocation is done).
3216 CONFIG_SPL_BSS_START_ADDR
3217 Link address for the BSS within the SPL binary.
3219 CONFIG_SPL_BSS_MAX_SIZE
3220 Maximum size in memory allocated to the SPL BSS.
3221 When defined, the linker checks that the actual memory used
3222 by SPL from __bss_start to __bss_end does not exceed it.
3223 CONFIG_SPL_MAX_FOOTPRINT and CONFIG_SPL_BSS_MAX_SIZE
3224 must not be both defined at the same time.
3227 Adress of the start of the stack SPL will use
3229 CONFIG_SPL_RELOC_STACK
3230 Adress of the start of the stack SPL will use after
3231 relocation. If unspecified, this is equal to
3234 CONFIG_SYS_SPL_MALLOC_START
3235 Starting address of the malloc pool used in SPL.
3237 CONFIG_SYS_SPL_MALLOC_SIZE
3238 The size of the malloc pool used in SPL.
3240 CONFIG_SPL_FRAMEWORK
3241 Enable the SPL framework under common/. This framework
3242 supports MMC, NAND and YMODEM loading of U-Boot and NAND
3243 NAND loading of the Linux Kernel.
3245 CONFIG_SPL_DISPLAY_PRINT
3246 For ARM, enable an optional function to print more information
3247 about the running system.
3249 CONFIG_SPL_INIT_MINIMAL
3250 Arch init code should be built for a very small image
3252 CONFIG_SPL_LIBCOMMON_SUPPORT
3253 Support for common/libcommon.o in SPL binary
3255 CONFIG_SPL_LIBDISK_SUPPORT
3256 Support for disk/libdisk.o in SPL binary
3258 CONFIG_SPL_I2C_SUPPORT
3259 Support for drivers/i2c/libi2c.o in SPL binary
3261 CONFIG_SPL_GPIO_SUPPORT
3262 Support for drivers/gpio/libgpio.o in SPL binary
3264 CONFIG_SPL_MMC_SUPPORT
3265 Support for drivers/mmc/libmmc.o in SPL binary
3267 CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_SECTOR,
3268 CONFIG_SYS_U_BOOT_MAX_SIZE_SECTORS,
3269 CONFIG_SYS_MMC_SD_FAT_BOOT_PARTITION
3270 Address, size and partition on the MMC to load U-Boot from
3271 when the MMC is being used in raw mode.
3273 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR
3274 Sector to load kernel uImage from when MMC is being
3275 used in raw mode (for Falcon mode)
3277 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR,
3278 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTORS
3279 Sector and number of sectors to load kernel argument
3280 parameters from when MMC is being used in raw mode
3283 CONFIG_SPL_FAT_SUPPORT
3284 Support for fs/fat/libfat.o in SPL binary
3286 CONFIG_SPL_FAT_LOAD_PAYLOAD_NAME
3287 Filename to read to load U-Boot when reading from FAT
3289 CONFIG_SPL_FAT_LOAD_KERNEL_NAME
3290 Filename to read to load kernel uImage when reading
3291 from FAT (for Falcon mode)
3293 CONFIG_SPL_FAT_LOAD_ARGS_NAME
3294 Filename to read to load kernel argument parameters
3295 when reading from FAT (for Falcon mode)
3297 CONFIG_SPL_MPC83XX_WAIT_FOR_NAND
3298 Set this for NAND SPL on PPC mpc83xx targets, so that
3299 start.S waits for the rest of the SPL to load before
3300 continuing (the hardware starts execution after just
3301 loading the first page rather than the full 4K).
3303 CONFIG_SPL_NAND_BASE
3304 Include nand_base.c in the SPL. Requires
3305 CONFIG_SPL_NAND_DRIVERS.
3307 CONFIG_SPL_NAND_DRIVERS
3308 SPL uses normal NAND drivers, not minimal drivers.
3311 Include standard software ECC in the SPL
3313 CONFIG_SPL_NAND_SIMPLE
3314 Support for NAND boot using simple NAND drivers that
3315 expose the cmd_ctrl() interface.
3317 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT
3318 Set for the SPL on PPC mpc8xxx targets, support for
3319 drivers/ddr/fsl/libddr.o in SPL binary.
3321 CONFIG_SPL_COMMON_INIT_DDR
3322 Set for common ddr init with serial presence detect in
3325 CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
3326 CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
3327 CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,
3328 CONFIG_SYS_NAND_ECCPOS, CONFIG_SYS_NAND_ECCSIZE,
3329 CONFIG_SYS_NAND_ECCBYTES
3330 Defines the size and behavior of the NAND that SPL uses
3333 CONFIG_SPL_NAND_BOOT
3334 Add support NAND boot
3336 CONFIG_SYS_NAND_U_BOOT_OFFS
3337 Location in NAND to read U-Boot from
3339 CONFIG_SYS_NAND_U_BOOT_DST
3340 Location in memory to load U-Boot to
3342 CONFIG_SYS_NAND_U_BOOT_SIZE
3343 Size of image to load
3345 CONFIG_SYS_NAND_U_BOOT_START
3346 Entry point in loaded image to jump to
3348 CONFIG_SYS_NAND_HW_ECC_OOBFIRST
3349 Define this if you need to first read the OOB and then the
3350 data. This is used for example on davinci plattforms.
3352 CONFIG_SPL_OMAP3_ID_NAND
3353 Support for an OMAP3-specific set of functions to return the
3354 ID and MFR of the first attached NAND chip, if present.
3356 CONFIG_SPL_SERIAL_SUPPORT
3357 Support for drivers/serial/libserial.o in SPL binary
3359 CONFIG_SPL_SPI_FLASH_SUPPORT
3360 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
3362 CONFIG_SPL_SPI_SUPPORT
3363 Support for drivers/spi/libspi.o in SPL binary
3365 CONFIG_SPL_RAM_DEVICE
3366 Support for running image already present in ram, in SPL binary
3368 CONFIG_SPL_LIBGENERIC_SUPPORT
3369 Support for lib/libgeneric.o in SPL binary
3371 CONFIG_SPL_ENV_SUPPORT
3372 Support for the environment operating in SPL binary
3374 CONFIG_SPL_NET_SUPPORT
3375 Support for the net/libnet.o in SPL binary.
3376 It conflicts with SPL env from storage medium specified by
3377 CONFIG_ENV_IS_xxx but CONFIG_ENV_IS_NOWHERE
3380 Image offset to which the SPL should be padded before appending
3381 the SPL payload. By default, this is defined as
3382 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3383 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3384 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3387 Final target image containing SPL and payload. Some SPLs
3388 use an arch-specific makefile fragment instead, for
3389 example if more than one image needs to be produced.
3391 CONFIG_FIT_SPL_PRINT
3392 Printing information about a FIT image adds quite a bit of
3393 code to SPL. So this is normally disabled in SPL. Use this
3394 option to re-enable it. This will affect the output of the
3395 bootm command when booting a FIT image.
3399 Enable building of TPL globally.
3402 Image offset to which the TPL should be padded before appending
3403 the TPL payload. By default, this is defined as
3404 CONFIG_SPL_MAX_SIZE, or 0 if CONFIG_SPL_MAX_SIZE is undefined.
3405 CONFIG_SPL_PAD_TO must be either 0, meaning to append the SPL
3406 payload without any padding, or >= CONFIG_SPL_MAX_SIZE.
3411 [so far only for SMDK2400 boards]
3413 - Modem support enable:
3414 CONFIG_MODEM_SUPPORT
3416 - RTS/CTS Flow control enable:
3419 - Modem debug support:
3420 CONFIG_MODEM_SUPPORT_DEBUG
3422 Enables debugging stuff (char screen[1024], dbg())
3423 for modem support. Useful only with BDI2000.
3425 - Interrupt support (PPC):
3427 There are common interrupt_init() and timer_interrupt()
3428 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
3429 for CPU specific initialization. interrupt_init_cpu()
3430 should set decrementer_count to appropriate value. If
3431 CPU resets decrementer automatically after interrupt
3432 (ppc4xx) it should set decrementer_count to zero.
3433 timer_interrupt() calls timer_interrupt_cpu() for CPU
3434 specific handling. If board has watchdog / status_led
3435 / other_activity_monitor it works automatically from
3436 general timer_interrupt().
3440 In the target system modem support is enabled when a
3441 specific key (key combination) is pressed during
3442 power-on. Otherwise U-Boot will boot normally
3443 (autoboot). The key_pressed() function is called from
3444 board_init(). Currently key_pressed() is a dummy
3445 function, returning 1 and thus enabling modem
3448 If there are no modem init strings in the
3449 environment, U-Boot proceed to autoboot; the
3450 previous output (banner, info printfs) will be
3453 See also: doc/README.Modem
3455 Board initialization settings:
3456 ------------------------------
3458 During Initialization u-boot calls a number of board specific functions
3459 to allow the preparation of board specific prerequisites, e.g. pin setup
3460 before drivers are initialized. To enable these callbacks the
3461 following configuration macros have to be defined. Currently this is
3462 architecture specific, so please check arch/your_architecture/lib/board.c
3463 typically in board_init_f() and board_init_r().
3465 - CONFIG_BOARD_EARLY_INIT_F: Call board_early_init_f()
3466 - CONFIG_BOARD_EARLY_INIT_R: Call board_early_init_r()
3467 - CONFIG_BOARD_LATE_INIT: Call board_late_init()
3468 - CONFIG_BOARD_POSTCLK_INIT: Call board_postclk_init()
3470 Configuration Settings:
3471 -----------------------
3473 - CONFIG_SYS_SUPPORT_64BIT_DATA: Defined automatically if compiled as 64-bit.
3474 Optionally it can be defined to support 64-bit memory commands.
3476 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
3477 undefine this when you're short of memory.
3479 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
3480 width of the commands listed in the 'help' command output.
3482 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
3483 prompt for user input.
3485 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
3487 - CONFIG_SYS_PBSIZE: Buffer size for Console output
3489 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
3491 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
3492 the application (usually a Linux kernel) when it is
3495 - CONFIG_SYS_BAUDRATE_TABLE:
3496 List of legal baudrate settings for this board.
3498 - CONFIG_SYS_CONSOLE_INFO_QUIET
3499 Suppress display of console information at boot.
3501 - CONFIG_SYS_CONSOLE_IS_IN_ENV
3502 If the board specific function
3503 extern int overwrite_console (void);
3504 returns 1, the stdin, stderr and stdout are switched to the
3505 serial port, else the settings in the environment are used.
3507 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
3508 Enable the call to overwrite_console().
3510 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
3511 Enable overwrite of previous console environment settings.
3513 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
3514 Begin and End addresses of the area used by the
3517 - CONFIG_SYS_ALT_MEMTEST:
3518 Enable an alternate, more extensive memory test.
3520 - CONFIG_SYS_MEMTEST_SCRATCH:
3521 Scratch address used by the alternate memory test
3522 You only need to set this if address zero isn't writeable
3524 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
3525 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
3526 this specified memory area will get subtracted from the top
3527 (end) of RAM and won't get "touched" at all by U-Boot. By
3528 fixing up gd->ram_size the Linux kernel should gets passed
3529 the now "corrected" memory size and won't touch it either.
3530 This should work for arch/ppc and arch/powerpc. Only Linux
3531 board ports in arch/powerpc with bootwrapper support that
3532 recalculate the memory size from the SDRAM controller setup
3533 will have to get fixed in Linux additionally.
3535 This option can be used as a workaround for the 440EPx/GRx
3536 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
3539 WARNING: Please make sure that this value is a multiple of
3540 the Linux page size (normally 4k). If this is not the case,
3541 then the end address of the Linux memory will be located at a
3542 non page size aligned address and this could cause major
3545 - CONFIG_SYS_LOADS_BAUD_CHANGE:
3546 Enable temporary baudrate change while serial download
3548 - CONFIG_SYS_SDRAM_BASE:
3549 Physical start address of SDRAM. _Must_ be 0 here.
3551 - CONFIG_SYS_MBIO_BASE:
3552 Physical start address of Motherboard I/O (if using a
3555 - CONFIG_SYS_FLASH_BASE:
3556 Physical start address of Flash memory.
3558 - CONFIG_SYS_MONITOR_BASE:
3559 Physical start address of boot monitor code (set by
3560 make config files to be same as the text base address
3561 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
3562 CONFIG_SYS_FLASH_BASE when booting from flash.
3564 - CONFIG_SYS_MONITOR_LEN:
3565 Size of memory reserved for monitor code, used to
3566 determine _at_compile_time_ (!) if the environment is
3567 embedded within the U-Boot image, or in a separate
3570 - CONFIG_SYS_MALLOC_LEN:
3571 Size of DRAM reserved for malloc() use.
3573 - CONFIG_SYS_BOOTM_LEN:
3574 Normally compressed uImages are limited to an
3575 uncompressed size of 8 MBytes. If this is not enough,
3576 you can define CONFIG_SYS_BOOTM_LEN in your board config file
3577 to adjust this setting to your needs.
3579 - CONFIG_SYS_BOOTMAPSZ:
3580 Maximum size of memory mapped by the startup code of
3581 the Linux kernel; all data that must be processed by
3582 the Linux kernel (bd_info, boot arguments, FDT blob if
3583 used) must be put below this limit, unless "bootm_low"
3584 environment variable is defined and non-zero. In such case
3585 all data for the Linux kernel must be between "bootm_low"
3586 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
3587 variable "bootm_mapsize" will override the value of
3588 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
3589 then the value in "bootm_size" will be used instead.
3591 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
3592 Enable initrd_high functionality. If defined then the
3593 initrd_high feature is enabled and the bootm ramdisk subcommand
3596 - CONFIG_SYS_BOOT_GET_CMDLINE:
3597 Enables allocating and saving kernel cmdline in space between
3598 "bootm_low" and "bootm_low" + BOOTMAPSZ.
3600 - CONFIG_SYS_BOOT_GET_KBD:
3601 Enables allocating and saving a kernel copy of the bd_info in
3602 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
3604 - CONFIG_SYS_MAX_FLASH_BANKS:
3605 Max number of Flash memory banks
3607 - CONFIG_SYS_MAX_FLASH_SECT:
3608 Max number of sectors on a Flash chip
3610 - CONFIG_SYS_FLASH_ERASE_TOUT:
3611 Timeout for Flash erase operations (in ms)
3613 - CONFIG_SYS_FLASH_WRITE_TOUT:
3614 Timeout for Flash write operations (in ms)
3616 - CONFIG_SYS_FLASH_LOCK_TOUT
3617 Timeout for Flash set sector lock bit operation (in ms)
3619 - CONFIG_SYS_FLASH_UNLOCK_TOUT
3620 Timeout for Flash clear lock bits operation (in ms)
3622 - CONFIG_SYS_FLASH_PROTECTION
3623 If defined, hardware flash sectors protection is used
3624 instead of U-Boot software protection.
3626 - CONFIG_SYS_DIRECT_FLASH_TFTP:
3628 Enable TFTP transfers directly to flash memory;
3629 without this option such a download has to be
3630 performed in two steps: (1) download to RAM, and (2)
3631 copy from RAM to flash.
3633 The two-step approach is usually more reliable, since
3634 you can check if the download worked before you erase
3635 the flash, but in some situations (when system RAM is
3636 too limited to allow for a temporary copy of the
3637 downloaded image) this option may be very useful.
3639 - CONFIG_SYS_FLASH_CFI:
3640 Define if the flash driver uses extra elements in the
3641 common flash structure for storing flash geometry.
3643 - CONFIG_FLASH_CFI_DRIVER
3644 This option also enables the building of the cfi_flash driver
3645 in the drivers directory
3647 - CONFIG_FLASH_CFI_MTD
3648 This option enables the building of the cfi_mtd driver
3649 in the drivers directory. The driver exports CFI flash
3652 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
3653 Use buffered writes to flash.
3655 - CONFIG_FLASH_SPANSION_S29WS_N
3656 s29ws-n MirrorBit flash has non-standard addresses for buffered
3659 - CONFIG_SYS_FLASH_QUIET_TEST
3660 If this option is defined, the common CFI flash doesn't
3661 print it's warning upon not recognized FLASH banks. This
3662 is useful, if some of the configured banks are only
3663 optionally available.
3665 - CONFIG_FLASH_SHOW_PROGRESS
3666 If defined (must be an integer), print out countdown
3667 digits and dots. Recommended value: 45 (9..1) for 80
3668 column displays, 15 (3..1) for 40 column displays.
3670 - CONFIG_FLASH_VERIFY
3671 If defined, the content of the flash (destination) is compared
3672 against the source after the write operation. An error message
3673 will be printed when the contents are not identical.
3674 Please note that this option is useless in nearly all cases,
3675 since such flash programming errors usually are detected earlier
3676 while unprotecting/erasing/programming. Please only enable
3677 this option if you really know what you are doing.
3679 - CONFIG_SYS_RX_ETH_BUFFER:
3680 Defines the number of Ethernet receive buffers. On some
3681 Ethernet controllers it is recommended to set this value
3682 to 8 or even higher (EEPRO100 or 405 EMAC), since all
3683 buffers can be full shortly after enabling the interface
3684 on high Ethernet traffic.
3685 Defaults to 4 if not defined.
3687 - CONFIG_ENV_MAX_ENTRIES
3689 Maximum number of entries in the hash table that is used
3690 internally to store the environment settings. The default
3691 setting is supposed to be generous and should work in most
3692 cases. This setting can be used to tune behaviour; see
3693 lib/hashtable.c for details.
3695 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3696 - CONFIG_ENV_FLAGS_LIST_STATIC
3697 Enable validation of the values given to environment variables when
3698 calling env set. Variables can be restricted to only decimal,
3699 hexadecimal, or boolean. If CONFIG_CMD_NET is also defined,
3700 the variables can also be restricted to IP address or MAC address.
3702 The format of the list is:
3703 type_attribute = [s|d|x|b|i|m]
3704 access_atribute = [a|r|o|c]
3705 attributes = type_attribute[access_atribute]
3706 entry = variable_name[:attributes]
3709 The type attributes are:
3710 s - String (default)
3713 b - Boolean ([1yYtT|0nNfF])
3717 The access attributes are:
3723 - CONFIG_ENV_FLAGS_LIST_DEFAULT
3724 Define this to a list (string) to define the ".flags"
3725 envirnoment variable in the default or embedded environment.
3727 - CONFIG_ENV_FLAGS_LIST_STATIC
3728 Define this to a list (string) to define validation that
3729 should be done if an entry is not found in the ".flags"
3730 environment variable. To override a setting in the static
3731 list, simply add an entry for the same variable name to the
3734 - CONFIG_ENV_ACCESS_IGNORE_FORCE
3735 If defined, don't allow the -f switch to env set override variable
3738 - CONFIG_SYS_GENERIC_BOARD
3739 This selects the architecture-generic board system instead of the
3740 architecture-specific board files. It is intended to move boards
3741 to this new framework over time. Defining this will disable the
3742 arch/foo/lib/board.c file and use common/board_f.c and
3743 common/board_r.c instead. To use this option your architecture
3744 must support it (i.e. must define __HAVE_ARCH_GENERIC_BOARD in
3745 its config.mk file). If you find problems enabling this option on
3746 your board please report the problem and send patches!
3748 - CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC (OMAP only)
3749 This is set by OMAP boards for the max time that reset should
3750 be asserted. See doc/README.omap-reset-time for details on how
3751 the value can be calulated on a given board.
3753 The following definitions that deal with the placement and management
3754 of environment data (variable area); in general, we support the
3755 following configurations:
3757 - CONFIG_BUILD_ENVCRC:
3759 Builds up envcrc with the target environment so that external utils
3760 may easily extract it and embed it in final U-Boot images.
3762 - CONFIG_ENV_IS_IN_FLASH:
3764 Define this if the environment is in flash memory.
3766 a) The environment occupies one whole flash sector, which is
3767 "embedded" in the text segment with the U-Boot code. This
3768 happens usually with "bottom boot sector" or "top boot
3769 sector" type flash chips, which have several smaller
3770 sectors at the start or the end. For instance, such a
3771 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
3772 such a case you would place the environment in one of the
3773 4 kB sectors - with U-Boot code before and after it. With
3774 "top boot sector" type flash chips, you would put the
3775 environment in one of the last sectors, leaving a gap
3776 between U-Boot and the environment.
3778 - CONFIG_ENV_OFFSET:
3780 Offset of environment data (variable area) to the
3781 beginning of flash memory; for instance, with bottom boot
3782 type flash chips the second sector can be used: the offset
3783 for this sector is given here.
3785 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
3789 This is just another way to specify the start address of
3790 the flash sector containing the environment (instead of
3793 - CONFIG_ENV_SECT_SIZE:
3795 Size of the sector containing the environment.
3798 b) Sometimes flash chips have few, equal sized, BIG sectors.
3799 In such a case you don't want to spend a whole sector for
3804 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
3805 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
3806 of this flash sector for the environment. This saves
3807 memory for the RAM copy of the environment.
3809 It may also save flash memory if you decide to use this
3810 when your environment is "embedded" within U-Boot code,
3811 since then the remainder of the flash sector could be used
3812 for U-Boot code. It should be pointed out that this is
3813 STRONGLY DISCOURAGED from a robustness point of view:
3814 updating the environment in flash makes it always
3815 necessary to erase the WHOLE sector. If something goes
3816 wrong before the contents has been restored from a copy in
3817 RAM, your target system will be dead.
3819 - CONFIG_ENV_ADDR_REDUND
3820 CONFIG_ENV_SIZE_REDUND
3822 These settings describe a second storage area used to hold
3823 a redundant copy of the environment data, so that there is
3824 a valid backup copy in case there is a power failure during
3825 a "saveenv" operation.
3827 BE CAREFUL! Any changes to the flash layout, and some changes to the
3828 source code will make it necessary to adapt <board>/u-boot.lds*
3832 - CONFIG_ENV_IS_IN_NVRAM:
3834 Define this if you have some non-volatile memory device
3835 (NVRAM, battery buffered SRAM) which you want to use for the
3841 These two #defines are used to determine the memory area you
3842 want to use for environment. It is assumed that this memory
3843 can just be read and written to, without any special
3846 BE CAREFUL! The first access to the environment happens quite early
3847 in U-Boot initalization (when we try to get the setting of for the
3848 console baudrate). You *MUST* have mapped your NVRAM area then, or
3851 Please note that even with NVRAM we still use a copy of the
3852 environment in RAM: we could work on NVRAM directly, but we want to
3853 keep settings there always unmodified except somebody uses "saveenv"
3854 to save the current settings.
3857 - CONFIG_ENV_IS_IN_EEPROM:
3859 Use this if you have an EEPROM or similar serial access
3860 device and a driver for it.
3862 - CONFIG_ENV_OFFSET:
3865 These two #defines specify the offset and size of the
3866 environment area within the total memory of your EEPROM.
3868 - CONFIG_SYS_I2C_EEPROM_ADDR:
3869 If defined, specified the chip address of the EEPROM device.
3870 The default address is zero.
3872 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
3873 If defined, the number of bits used to address bytes in a
3874 single page in the EEPROM device. A 64 byte page, for example
3875 would require six bits.
3877 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
3878 If defined, the number of milliseconds to delay between
3879 page writes. The default is zero milliseconds.
3881 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
3882 The length in bytes of the EEPROM memory array address. Note
3883 that this is NOT the chip address length!
3885 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
3886 EEPROM chips that implement "address overflow" are ones
3887 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
3888 address and the extra bits end up in the "chip address" bit
3889 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
3892 Note that we consider the length of the address field to
3893 still be one byte because the extra address bits are hidden
3894 in the chip address.
3896 - CONFIG_SYS_EEPROM_SIZE:
3897 The size in bytes of the EEPROM device.
3899 - CONFIG_ENV_EEPROM_IS_ON_I2C
3900 define this, if you have I2C and SPI activated, and your
3901 EEPROM, which holds the environment, is on the I2C bus.
3903 - CONFIG_I2C_ENV_EEPROM_BUS
3904 if you have an Environment on an EEPROM reached over
3905 I2C muxes, you can define here, how to reach this
3906 EEPROM. For example:
3908 #define CONFIG_I2C_ENV_EEPROM_BUS 1
3910 EEPROM which holds the environment, is reached over
3911 a pca9547 i2c mux with address 0x70, channel 3.
3913 - CONFIG_ENV_IS_IN_DATAFLASH:
3915 Define this if you have a DataFlash memory device which you
3916 want to use for the environment.
3918 - CONFIG_ENV_OFFSET:
3922 These three #defines specify the offset and size of the
3923 environment area within the total memory of your DataFlash placed
3924 at the specified address.
3926 - CONFIG_ENV_IS_IN_REMOTE:
3928 Define this if you have a remote memory space which you
3929 want to use for the local device's environment.
3934 These two #defines specify the address and size of the
3935 environment area within the remote memory space. The
3936 local device can get the environment from remote memory
3937 space by SRIO or PCIE links.
3939 BE CAREFUL! For some special cases, the local device can not use
3940 "saveenv" command. For example, the local device will get the
3941 environment stored in a remote NOR flash by SRIO or PCIE link,
3942 but it can not erase, write this NOR flash by SRIO or PCIE interface.
3944 - CONFIG_ENV_IS_IN_NAND:
3946 Define this if you have a NAND device which you want to use
3947 for the environment.
3949 - CONFIG_ENV_OFFSET:
3952 These two #defines specify the offset and size of the environment
3953 area within the first NAND device. CONFIG_ENV_OFFSET must be
3954 aligned to an erase block boundary.
3956 - CONFIG_ENV_OFFSET_REDUND (optional):
3958 This setting describes a second storage area of CONFIG_ENV_SIZE
3959 size used to hold a redundant copy of the environment data, so
3960 that there is a valid backup copy in case there is a power failure
3961 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
3962 aligned to an erase block boundary.
3964 - CONFIG_ENV_RANGE (optional):
3966 Specifies the length of the region in which the environment
3967 can be written. This should be a multiple of the NAND device's
3968 block size. Specifying a range with more erase blocks than
3969 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
3970 the range to be avoided.
3972 - CONFIG_ENV_OFFSET_OOB (optional):
3974 Enables support for dynamically retrieving the offset of the
3975 environment from block zero's out-of-band data. The
3976 "nand env.oob" command can be used to record this offset.
3977 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
3978 using CONFIG_ENV_OFFSET_OOB.
3980 - CONFIG_NAND_ENV_DST
3982 Defines address in RAM to which the nand_spl code should copy the
3983 environment. If redundant environment is used, it will be copied to
3984 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
3986 - CONFIG_ENV_IS_IN_UBI:
3988 Define this if you have an UBI volume that you want to use for the
3989 environment. This has the benefit of wear-leveling the environment
3990 accesses, which is important on NAND.
3992 - CONFIG_ENV_UBI_PART:
3994 Define this to a string that is the mtd partition containing the UBI.
3996 - CONFIG_ENV_UBI_VOLUME:
3998 Define this to the name of the volume that you want to store the
4001 - CONFIG_ENV_UBI_VOLUME_REDUND:
4003 Define this to the name of another volume to store a second copy of
4004 the environment in. This will enable redundant environments in UBI.
4005 It is assumed that both volumes are in the same MTD partition.
4007 - CONFIG_UBI_SILENCE_MSG
4008 - CONFIG_UBIFS_SILENCE_MSG
4010 You will probably want to define these to avoid a really noisy system
4011 when storing the env in UBI.
4013 - CONFIG_ENV_IS_IN_MMC:
4015 Define this if you have an MMC device which you want to use for the
4018 - CONFIG_SYS_MMC_ENV_DEV:
4020 Specifies which MMC device the environment is stored in.
4022 - CONFIG_SYS_MMC_ENV_PART (optional):
4024 Specifies which MMC partition the environment is stored in. If not
4025 set, defaults to partition 0, the user area. Common values might be
4026 1 (first MMC boot partition), 2 (second MMC boot partition).
4028 - CONFIG_ENV_OFFSET:
4031 These two #defines specify the offset and size of the environment
4032 area within the specified MMC device.
4034 If offset is positive (the usual case), it is treated as relative to
4035 the start of the MMC partition. If offset is negative, it is treated
4036 as relative to the end of the MMC partition. This can be useful if
4037 your board may be fitted with different MMC devices, which have
4038 different sizes for the MMC partitions, and you always want the
4039 environment placed at the very end of the partition, to leave the
4040 maximum possible space before it, to store other data.
4042 These two values are in units of bytes, but must be aligned to an
4043 MMC sector boundary.
4045 - CONFIG_ENV_OFFSET_REDUND (optional):
4047 Specifies a second storage area, of CONFIG_ENV_SIZE size, used to
4048 hold a redundant copy of the environment data. This provides a
4049 valid backup copy in case the other copy is corrupted, e.g. due
4050 to a power failure during a "saveenv" operation.
4052 This value may also be positive or negative; this is handled in the
4053 same way as CONFIG_ENV_OFFSET.
4055 This value is also in units of bytes, but must also be aligned to
4056 an MMC sector boundary.
4058 - CONFIG_ENV_SIZE_REDUND (optional):
4060 This value need not be set, even when CONFIG_ENV_OFFSET_REDUND is
4061 set. If this value is set, it must be set to the same value as
4064 - CONFIG_SYS_SPI_INIT_OFFSET
4066 Defines offset to the initial SPI buffer area in DPRAM. The
4067 area is used at an early stage (ROM part) if the environment
4068 is configured to reside in the SPI EEPROM: We need a 520 byte
4069 scratch DPRAM area. It is used between the two initialization
4070 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
4071 to be a good choice since it makes it far enough from the
4072 start of the data area as well as from the stack pointer.
4074 Please note that the environment is read-only until the monitor
4075 has been relocated to RAM and a RAM copy of the environment has been
4076 created; also, when using EEPROM you will have to use getenv_f()
4077 until then to read environment variables.
4079 The environment is protected by a CRC32 checksum. Before the monitor
4080 is relocated into RAM, as a result of a bad CRC you will be working
4081 with the compiled-in default environment - *silently*!!! [This is
4082 necessary, because the first environment variable we need is the
4083 "baudrate" setting for the console - if we have a bad CRC, we don't
4084 have any device yet where we could complain.]
4086 Note: once the monitor has been relocated, then it will complain if
4087 the default environment is used; a new CRC is computed as soon as you
4088 use the "saveenv" command to store a valid environment.
4090 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
4091 Echo the inverted Ethernet link state to the fault LED.
4093 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
4094 also needs to be defined.
4096 - CONFIG_SYS_FAULT_MII_ADDR:
4097 MII address of the PHY to check for the Ethernet link state.
4099 - CONFIG_NS16550_MIN_FUNCTIONS:
4100 Define this if you desire to only have use of the NS16550_init
4101 and NS16550_putc functions for the serial driver located at
4102 drivers/serial/ns16550.c. This option is useful for saving
4103 space for already greatly restricted images, including but not
4104 limited to NAND_SPL configurations.
4106 - CONFIG_DISPLAY_BOARDINFO
4107 Display information about the board that U-Boot is running on
4108 when U-Boot starts up. The board function checkboard() is called
4111 - CONFIG_DISPLAY_BOARDINFO_LATE
4112 Similar to the previous option, but display this information
4113 later, once stdio is running and output goes to the LCD, if
4116 Low Level (hardware related) configuration options:
4117 ---------------------------------------------------
4119 - CONFIG_SYS_CACHELINE_SIZE:
4120 Cache Line Size of the CPU.
4122 - CONFIG_SYS_DEFAULT_IMMR:
4123 Default address of the IMMR after system reset.
4125 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
4126 and RPXsuper) to be able to adjust the position of
4127 the IMMR register after a reset.
4129 - CONFIG_SYS_CCSRBAR_DEFAULT:
4130 Default (power-on reset) physical address of CCSR on Freescale
4133 - CONFIG_SYS_CCSRBAR:
4134 Virtual address of CCSR. On a 32-bit build, this is typically
4135 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
4137 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
4138 for cross-platform code that uses that macro instead.
4140 - CONFIG_SYS_CCSRBAR_PHYS:
4141 Physical address of CCSR. CCSR can be relocated to a new
4142 physical address, if desired. In this case, this macro should
4143 be set to that address. Otherwise, it should be set to the
4144 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
4145 is typically relocated on 36-bit builds. It is recommended
4146 that this macro be defined via the _HIGH and _LOW macros:
4148 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
4149 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
4151 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
4152 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
4153 either 0 (32-bit build) or 0xF (36-bit build). This macro is
4154 used in assembly code, so it must not contain typecasts or
4155 integer size suffixes (e.g. "ULL").
4157 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
4158 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
4159 used in assembly code, so it must not contain typecasts or
4160 integer size suffixes (e.g. "ULL").
4162 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
4163 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
4164 forced to a value that ensures that CCSR is not relocated.
4166 - Floppy Disk Support:
4167 CONFIG_SYS_FDC_DRIVE_NUMBER
4169 the default drive number (default value 0)
4171 CONFIG_SYS_ISA_IO_STRIDE
4173 defines the spacing between FDC chipset registers
4176 CONFIG_SYS_ISA_IO_OFFSET
4178 defines the offset of register from address. It
4179 depends on which part of the data bus is connected to
4180 the FDC chipset. (default value 0)
4182 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
4183 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
4186 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
4187 fdc_hw_init() is called at the beginning of the FDC
4188 setup. fdc_hw_init() must be provided by the board
4189 source code. It is used to make hardware dependant
4193 Most IDE controllers were designed to be connected with PCI
4194 interface. Only few of them were designed for AHB interface.
4195 When software is doing ATA command and data transfer to
4196 IDE devices through IDE-AHB controller, some additional
4197 registers accessing to these kind of IDE-AHB controller
4200 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
4201 DO NOT CHANGE unless you know exactly what you're
4202 doing! (11-4) [MPC8xx/82xx systems only]
4204 - CONFIG_SYS_INIT_RAM_ADDR:
4206 Start address of memory area that can be used for
4207 initial data and stack; please note that this must be
4208 writable memory that is working WITHOUT special
4209 initialization, i. e. you CANNOT use normal RAM which
4210 will become available only after programming the
4211 memory controller and running certain initialization
4214 U-Boot uses the following memory types:
4215 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
4216 - MPC824X: data cache
4217 - PPC4xx: data cache
4219 - CONFIG_SYS_GBL_DATA_OFFSET:
4221 Offset of the initial data structure in the memory
4222 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
4223 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
4224 data is located at the end of the available space
4225 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
4226 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
4227 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
4228 CONFIG_SYS_GBL_DATA_OFFSET) downward.
4231 On the MPC824X (or other systems that use the data
4232 cache for initial memory) the address chosen for
4233 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
4234 point to an otherwise UNUSED address space between
4235 the top of RAM and the start of the PCI space.
4237 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
4239 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
4241 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
4243 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
4245 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
4247 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
4249 - CONFIG_SYS_OR_TIMING_SDRAM:
4252 - CONFIG_SYS_MAMR_PTA:
4253 periodic timer for refresh
4255 - CONFIG_SYS_DER: Debug Event Register (37-47)
4257 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
4258 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
4259 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
4260 CONFIG_SYS_BR1_PRELIM:
4261 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
4263 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
4264 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
4265 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
4266 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
4268 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
4269 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
4270 Machine Mode Register and Memory Periodic Timer
4271 Prescaler definitions (SDRAM timing)
4273 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
4274 enable I2C microcode relocation patch (MPC8xx);
4275 define relocation offset in DPRAM [DSP2]
4277 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
4278 enable SMC microcode relocation patch (MPC8xx);
4279 define relocation offset in DPRAM [SMC1]
4281 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
4282 enable SPI microcode relocation patch (MPC8xx);
4283 define relocation offset in DPRAM [SCC4]
4285 - CONFIG_SYS_USE_OSCCLK:
4286 Use OSCM clock mode on MBX8xx board. Be careful,
4287 wrong setting might damage your board. Read
4288 doc/README.MBX before setting this variable!
4290 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
4291 Offset of the bootmode word in DPRAM used by post
4292 (Power On Self Tests). This definition overrides
4293 #define'd default value in commproc.h resp.
4296 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
4297 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
4298 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
4299 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
4300 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
4301 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
4302 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
4303 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
4304 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
4306 - CONFIG_PCI_DISABLE_PCIE:
4307 Disable PCI-Express on systems where it is supported but not
4310 - CONFIG_PCI_ENUM_ONLY
4311 Only scan through and get the devices on the busses.
4312 Don't do any setup work, presumably because someone or
4313 something has already done it, and we don't need to do it
4314 a second time. Useful for platforms that are pre-booted
4315 by coreboot or similar.
4317 - CONFIG_PCI_INDIRECT_BRIDGE:
4318 Enable support for indirect PCI bridges.
4321 Chip has SRIO or not
4324 Board has SRIO 1 port available
4327 Board has SRIO 2 port available
4329 - CONFIG_SRIO_PCIE_BOOT_MASTER
4330 Board can support master function for Boot from SRIO and PCIE
4332 - CONFIG_SYS_SRIOn_MEM_VIRT:
4333 Virtual Address of SRIO port 'n' memory region
4335 - CONFIG_SYS_SRIOn_MEM_PHYS:
4336 Physical Address of SRIO port 'n' memory region
4338 - CONFIG_SYS_SRIOn_MEM_SIZE:
4339 Size of SRIO port 'n' memory region
4341 - CONFIG_SYS_NAND_BUSWIDTH_16BIT
4342 Defined to tell the NAND controller that the NAND chip is using
4344 Not all NAND drivers use this symbol.
4345 Example of drivers that use it:
4346 - drivers/mtd/nand/ndfc.c
4347 - drivers/mtd/nand/mxc_nand.c
4349 - CONFIG_SYS_NDFC_EBC0_CFG
4350 Sets the EBC0_CFG register for the NDFC. If not defined
4351 a default value will be used.
4354 Get DDR timing information from an I2C EEPROM. Common
4355 with pluggable memory modules such as SODIMMs
4358 I2C address of the SPD EEPROM
4360 - CONFIG_SYS_SPD_BUS_NUM
4361 If SPD EEPROM is on an I2C bus other than the first
4362 one, specify here. Note that the value must resolve
4363 to something your driver can deal with.
4365 - CONFIG_SYS_DDR_RAW_TIMING
4366 Get DDR timing information from other than SPD. Common with
4367 soldered DDR chips onboard without SPD. DDR raw timing
4368 parameters are extracted from datasheet and hard-coded into
4369 header files or board specific files.
4371 - CONFIG_FSL_DDR_INTERACTIVE
4372 Enable interactive DDR debugging. See doc/README.fsl-ddr.
4374 - CONFIG_SYS_83XX_DDR_USES_CS0
4375 Only for 83xx systems. If specified, then DDR should
4376 be configured using CS0 and CS1 instead of CS2 and CS3.
4378 - CONFIG_ETHER_ON_FEC[12]
4379 Define to enable FEC[12] on a 8xx series processor.
4381 - CONFIG_FEC[12]_PHY
4382 Define to the hardcoded PHY address which corresponds
4383 to the given FEC; i. e.
4384 #define CONFIG_FEC1_PHY 4
4385 means that the PHY with address 4 is connected to FEC1
4387 When set to -1, means to probe for first available.
4389 - CONFIG_FEC[12]_PHY_NORXERR
4390 The PHY does not have a RXERR line (RMII only).
4391 (so program the FEC to ignore it).
4394 Enable RMII mode for all FECs.
4395 Note that this is a global option, we can't
4396 have one FEC in standard MII mode and another in RMII mode.
4398 - CONFIG_CRC32_VERIFY
4399 Add a verify option to the crc32 command.
4402 => crc32 -v <address> <count> <crc32>
4404 Where address/count indicate a memory area
4405 and crc32 is the correct crc32 which the
4409 Add the "loopw" memory command. This only takes effect if
4410 the memory commands are activated globally (CONFIG_CMD_MEM).
4413 Add the "mdc" and "mwc" memory commands. These are cyclic
4418 This command will print 4 bytes (10,11,12,13) each 500 ms.
4420 => mwc.l 100 12345678 10
4421 This command will write 12345678 to address 100 all 10 ms.
4423 This only takes effect if the memory commands are activated
4424 globally (CONFIG_CMD_MEM).
4426 - CONFIG_SKIP_LOWLEVEL_INIT
4427 [ARM, NDS32, MIPS only] If this variable is defined, then certain
4428 low level initializations (like setting up the memory
4429 controller) are omitted and/or U-Boot does not
4430 relocate itself into RAM.
4432 Normally this variable MUST NOT be defined. The only
4433 exception is when U-Boot is loaded (to RAM) by some
4434 other boot loader or by a debugger which performs
4435 these initializations itself.
4438 Modifies the behaviour of start.S when compiling a loader
4439 that is executed before the actual U-Boot. E.g. when
4440 compiling a NAND SPL.
4443 Modifies the behaviour of start.S when compiling a loader
4444 that is executed after the SPL and before the actual U-Boot.
4445 It is loaded by the SPL.
4447 - CONFIG_SYS_MPC85XX_NO_RESETVEC
4448 Only for 85xx systems. If this variable is specified, the section
4449 .resetvec is not kept and the section .bootpg is placed in the
4450 previous 4k of the .text section.
4452 - CONFIG_ARCH_MAP_SYSMEM
4453 Generally U-Boot (and in particular the md command) uses
4454 effective address. It is therefore not necessary to regard
4455 U-Boot address as virtual addresses that need to be translated
4456 to physical addresses. However, sandbox requires this, since
4457 it maintains its own little RAM buffer which contains all
4458 addressable memory. This option causes some memory accesses
4459 to be mapped through map_sysmem() / unmap_sysmem().
4461 - CONFIG_USE_ARCH_MEMCPY
4462 CONFIG_USE_ARCH_MEMSET
4463 If these options are used a optimized version of memcpy/memset will
4464 be used if available. These functions may be faster under some
4465 conditions but may increase the binary size.
4467 - CONFIG_X86_RESET_VECTOR
4468 If defined, the x86 reset vector code is included. This is not
4469 needed when U-Boot is running from Coreboot.
4472 Defines the MPU clock speed (in MHz).
4474 NOTE : currently only supported on AM335x platforms.
4476 - CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC:
4477 Enables the RTC32K OSC on AM33xx based plattforms
4479 Freescale QE/FMAN Firmware Support:
4480 -----------------------------------
4482 The Freescale QUICCEngine (QE) and Frame Manager (FMAN) both support the
4483 loading of "firmware", which is encoded in the QE firmware binary format.
4484 This firmware often needs to be loaded during U-Boot booting, so macros
4485 are used to identify the storage device (NOR flash, SPI, etc) and the address
4488 - CONFIG_SYS_QE_FMAN_FW_ADDR
4489 The address in the storage device where the firmware is located. The
4490 meaning of this address depends on which CONFIG_SYS_QE_FW_IN_xxx macro
4493 - CONFIG_SYS_QE_FMAN_FW_LENGTH
4494 The maximum possible size of the firmware. The firmware binary format
4495 has a field that specifies the actual size of the firmware, but it
4496 might not be possible to read any part of the firmware unless some
4497 local storage is allocated to hold the entire firmware first.
4499 - CONFIG_SYS_QE_FMAN_FW_IN_NOR
4500 Specifies that QE/FMAN firmware is located in NOR flash, mapped as
4501 normal addressable memory via the LBC. CONFIG_SYS_FMAN_FW_ADDR is the
4502 virtual address in NOR flash.
4504 - CONFIG_SYS_QE_FMAN_FW_IN_NAND
4505 Specifies that QE/FMAN firmware is located in NAND flash.
4506 CONFIG_SYS_FMAN_FW_ADDR is the offset within NAND flash.
4508 - CONFIG_SYS_QE_FMAN_FW_IN_MMC
4509 Specifies that QE/FMAN firmware is located on the primary SD/MMC
4510 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4512 - CONFIG_SYS_QE_FMAN_FW_IN_SPIFLASH
4513 Specifies that QE/FMAN firmware is located on the primary SPI
4514 device. CONFIG_SYS_FMAN_FW_ADDR is the byte offset on that device.
4516 - CONFIG_SYS_QE_FMAN_FW_IN_REMOTE
4517 Specifies that QE/FMAN firmware is located in the remote (master)
4518 memory space. CONFIG_SYS_FMAN_FW_ADDR is a virtual address which
4519 can be mapped from slave TLB->slave LAW->slave SRIO or PCIE outbound
4520 window->master inbound window->master LAW->the ucode address in
4521 master's memory space.
4523 Building the Software:
4524 ======================
4526 Building U-Boot has been tested in several native build environments
4527 and in many different cross environments. Of course we cannot support
4528 all possibly existing versions of cross development tools in all
4529 (potentially obsolete) versions. In case of tool chain problems we
4530 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
4531 which is extensively used to build and test U-Boot.
4533 If you are not using a native environment, it is assumed that you
4534 have GNU cross compiling tools available in your path. In this case,
4535 you must set the environment variable CROSS_COMPILE in your shell.
4536 Note that no changes to the Makefile or any other source files are
4537 necessary. For example using the ELDK on a 4xx CPU, please enter:
4539 $ CROSS_COMPILE=ppc_4xx-
4540 $ export CROSS_COMPILE
4542 Note: If you wish to generate Windows versions of the utilities in
4543 the tools directory you can use the MinGW toolchain
4544 (http://www.mingw.org). Set your HOST tools to the MinGW
4545 toolchain and execute 'make tools'. For example:
4547 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
4549 Binaries such as tools/mkimage.exe will be created which can
4550 be executed on computers running Windows.
4552 U-Boot is intended to be simple to build. After installing the
4553 sources you must configure U-Boot for one specific board type. This
4558 where "NAME_config" is the name of one of the existing configu-
4559 rations; see boards.cfg for supported names.
4561 Note: for some board special configuration names may exist; check if
4562 additional information is available from the board vendor; for
4563 instance, the TQM823L systems are available without (standard)
4564 or with LCD support. You can select such additional "features"
4565 when choosing the configuration, i. e.
4568 - will configure for a plain TQM823L, i. e. no LCD support
4570 make TQM823L_LCD_config
4571 - will configure for a TQM823L with U-Boot console on LCD
4576 Finally, type "make all", and you should get some working U-Boot
4577 images ready for download to / installation on your system:
4579 - "u-boot.bin" is a raw binary image
4580 - "u-boot" is an image in ELF binary format
4581 - "u-boot.srec" is in Motorola S-Record format
4583 By default the build is performed locally and the objects are saved
4584 in the source directory. One of the two methods can be used to change
4585 this behavior and build U-Boot to some external directory:
4587 1. Add O= to the make command line invocations:
4589 make O=/tmp/build distclean
4590 make O=/tmp/build NAME_config
4591 make O=/tmp/build all
4593 2. Set environment variable BUILD_DIR to point to the desired location:
4595 export BUILD_DIR=/tmp/build
4600 Note that the command line "O=" setting overrides the BUILD_DIR environment
4604 Please be aware that the Makefiles assume you are using GNU make, so
4605 for instance on NetBSD you might need to use "gmake" instead of
4609 If the system board that you have is not listed, then you will need
4610 to port U-Boot to your hardware platform. To do this, follow these
4613 1. Add a new configuration option for your board to the toplevel
4614 "boards.cfg" file, using the existing entries as examples.
4615 Follow the instructions there to keep the boards in order.
4616 2. Create a new directory to hold your board specific code. Add any
4617 files you need. In your board directory, you will need at least
4618 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
4619 3. Create a new configuration file "include/configs/<board>.h" for
4621 3. If you're porting U-Boot to a new CPU, then also create a new
4622 directory to hold your CPU specific code. Add any files you need.
4623 4. Run "make <board>_config" with your new name.
4624 5. Type "make", and you should get a working "u-boot.srec" file
4625 to be installed on your target system.
4626 6. Debug and solve any problems that might arise.
4627 [Of course, this last step is much harder than it sounds.]
4630 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
4631 ==============================================================
4633 If you have modified U-Boot sources (for instance added a new board
4634 or support for new devices, a new CPU, etc.) you are expected to
4635 provide feedback to the other developers. The feedback normally takes
4636 the form of a "patch", i. e. a context diff against a certain (latest
4637 official or latest in the git repository) version of U-Boot sources.
4639 But before you submit such a patch, please verify that your modifi-
4640 cation did not break existing code. At least make sure that *ALL* of
4641 the supported boards compile WITHOUT ANY compiler warnings. To do so,
4642 just run the "MAKEALL" script, which will configure and build U-Boot
4643 for ALL supported system. Be warned, this will take a while. You can
4644 select which (cross) compiler to use by passing a `CROSS_COMPILE'
4645 environment variable to the script, i. e. to use the ELDK cross tools
4648 CROSS_COMPILE=ppc_8xx- MAKEALL
4650 or to build on a native PowerPC system you can type
4652 CROSS_COMPILE=' ' MAKEALL
4654 When using the MAKEALL script, the default behaviour is to build
4655 U-Boot in the source directory. This location can be changed by
4656 setting the BUILD_DIR environment variable. Also, for each target
4657 built, the MAKEALL script saves two log files (<target>.ERR and
4658 <target>.MAKEALL) in the <source dir>/LOG directory. This default
4659 location can be changed by setting the MAKEALL_LOGDIR environment
4660 variable. For example:
4662 export BUILD_DIR=/tmp/build
4663 export MAKEALL_LOGDIR=/tmp/log
4664 CROSS_COMPILE=ppc_8xx- MAKEALL
4666 With the above settings build objects are saved in the /tmp/build,
4667 log files are saved in the /tmp/log and the source tree remains clean
4668 during the whole build process.
4671 See also "U-Boot Porting Guide" below.
4674 Monitor Commands - Overview:
4675 ============================
4677 go - start application at address 'addr'
4678 run - run commands in an environment variable
4679 bootm - boot application image from memory
4680 bootp - boot image via network using BootP/TFTP protocol
4681 bootz - boot zImage from memory
4682 tftpboot- boot image via network using TFTP protocol
4683 and env variables "ipaddr" and "serverip"
4684 (and eventually "gatewayip")
4685 tftpput - upload a file via network using TFTP protocol
4686 rarpboot- boot image via network using RARP/TFTP protocol
4687 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
4688 loads - load S-Record file over serial line
4689 loadb - load binary file over serial line (kermit mode)
4691 mm - memory modify (auto-incrementing)
4692 nm - memory modify (constant address)
4693 mw - memory write (fill)
4695 cmp - memory compare
4696 crc32 - checksum calculation
4697 i2c - I2C sub-system
4698 sspi - SPI utility commands
4699 base - print or set address offset
4700 printenv- print environment variables
4701 setenv - set environment variables
4702 saveenv - save environment variables to persistent storage
4703 protect - enable or disable FLASH write protection
4704 erase - erase FLASH memory
4705 flinfo - print FLASH memory information
4706 nand - NAND memory operations (see doc/README.nand)
4707 bdinfo - print Board Info structure
4708 iminfo - print header information for application image
4709 coninfo - print console devices and informations
4710 ide - IDE sub-system
4711 loop - infinite loop on address range
4712 loopw - infinite write loop on address range
4713 mtest - simple RAM test
4714 icache - enable or disable instruction cache
4715 dcache - enable or disable data cache
4716 reset - Perform RESET of the CPU
4717 echo - echo args to console
4718 version - print monitor version
4719 help - print online help
4720 ? - alias for 'help'
4723 Monitor Commands - Detailed Description:
4724 ========================================
4728 For now: just type "help <command>".
4731 Environment Variables:
4732 ======================
4734 U-Boot supports user configuration using Environment Variables which
4735 can be made persistent by saving to Flash memory.
4737 Environment Variables are set using "setenv", printed using
4738 "printenv", and saved to Flash using "saveenv". Using "setenv"
4739 without a value can be used to delete a variable from the
4740 environment. As long as you don't save the environment you are
4741 working with an in-memory copy. In case the Flash area containing the
4742 environment is erased by accident, a default environment is provided.
4744 Some configuration options can be set using Environment Variables.
4746 List of environment variables (most likely not complete):
4748 baudrate - see CONFIG_BAUDRATE
4750 bootdelay - see CONFIG_BOOTDELAY
4752 bootcmd - see CONFIG_BOOTCOMMAND
4754 bootargs - Boot arguments when booting an RTOS image
4756 bootfile - Name of the image to load with TFTP
4758 bootm_low - Memory range available for image processing in the bootm
4759 command can be restricted. This variable is given as
4760 a hexadecimal number and defines lowest address allowed
4761 for use by the bootm command. See also "bootm_size"
4762 environment variable. Address defined by "bootm_low" is
4763 also the base of the initial memory mapping for the Linux
4764 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
4767 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
4768 This variable is given as a hexadecimal number and it
4769 defines the size of the memory region starting at base
4770 address bootm_low that is accessible by the Linux kernel
4771 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
4772 as the default value if it is defined, and bootm_size is
4775 bootm_size - Memory range available for image processing in the bootm
4776 command can be restricted. This variable is given as
4777 a hexadecimal number and defines the size of the region
4778 allowed for use by the bootm command. See also "bootm_low"
4779 environment variable.
4781 updatefile - Location of the software update file on a TFTP server, used
4782 by the automatic software update feature. Please refer to
4783 documentation in doc/README.update for more details.
4785 autoload - if set to "no" (any string beginning with 'n'),
4786 "bootp" will just load perform a lookup of the
4787 configuration from the BOOTP server, but not try to
4788 load any image using TFTP
4790 autostart - if set to "yes", an image loaded using the "bootp",
4791 "rarpboot", "tftpboot" or "diskboot" commands will
4792 be automatically started (by internally calling
4795 If set to "no", a standalone image passed to the
4796 "bootm" command will be copied to the load address
4797 (and eventually uncompressed), but NOT be started.
4798 This can be used to load and uncompress arbitrary
4801 fdt_high - if set this restricts the maximum address that the
4802 flattened device tree will be copied into upon boot.
4803 For example, if you have a system with 1 GB memory
4804 at physical address 0x10000000, while Linux kernel
4805 only recognizes the first 704 MB as low memory, you
4806 may need to set fdt_high as 0x3C000000 to have the
4807 device tree blob be copied to the maximum address
4808 of the 704 MB low memory, so that Linux kernel can
4809 access it during the boot procedure.
4811 If this is set to the special value 0xFFFFFFFF then
4812 the fdt will not be copied at all on boot. For this
4813 to work it must reside in writable memory, have
4814 sufficient padding on the end of it for u-boot to
4815 add the information it needs into it, and the memory
4816 must be accessible by the kernel.
4818 fdtcontroladdr- if set this is the address of the control flattened
4819 device tree used by U-Boot when CONFIG_OF_CONTROL is
4822 i2cfast - (PPC405GP|PPC405EP only)
4823 if set to 'y' configures Linux I2C driver for fast
4824 mode (400kHZ). This environment variable is used in
4825 initialization code. So, for changes to be effective
4826 it must be saved and board must be reset.
4828 initrd_high - restrict positioning of initrd images:
4829 If this variable is not set, initrd images will be
4830 copied to the highest possible address in RAM; this
4831 is usually what you want since it allows for
4832 maximum initrd size. If for some reason you want to
4833 make sure that the initrd image is loaded below the
4834 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
4835 variable to a value of "no" or "off" or "0".
4836 Alternatively, you can set it to a maximum upper
4837 address to use (U-Boot will still check that it
4838 does not overwrite the U-Boot stack and data).
4840 For instance, when you have a system with 16 MB
4841 RAM, and want to reserve 4 MB from use by Linux,
4842 you can do this by adding "mem=12M" to the value of
4843 the "bootargs" variable. However, now you must make
4844 sure that the initrd image is placed in the first
4845 12 MB as well - this can be done with
4847 setenv initrd_high 00c00000
4849 If you set initrd_high to 0xFFFFFFFF, this is an
4850 indication to U-Boot that all addresses are legal
4851 for the Linux kernel, including addresses in flash
4852 memory. In this case U-Boot will NOT COPY the
4853 ramdisk at all. This may be useful to reduce the
4854 boot time on your system, but requires that this
4855 feature is supported by your Linux kernel.
4857 ipaddr - IP address; needed for tftpboot command
4859 loadaddr - Default load address for commands like "bootp",
4860 "rarpboot", "tftpboot", "loadb" or "diskboot"
4862 loads_echo - see CONFIG_LOADS_ECHO
4864 serverip - TFTP server IP address; needed for tftpboot command
4866 bootretry - see CONFIG_BOOT_RETRY_TIME
4868 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
4870 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
4872 ethprime - controls which interface is used first.
4874 ethact - controls which interface is currently active.
4875 For example you can do the following
4877 => setenv ethact FEC
4878 => ping 192.168.0.1 # traffic sent on FEC
4879 => setenv ethact SCC
4880 => ping 10.0.0.1 # traffic sent on SCC
4882 ethrotate - When set to "no" U-Boot does not go through all
4883 available network interfaces.
4884 It just stays at the currently selected interface.
4886 netretry - When set to "no" each network operation will
4887 either succeed or fail without retrying.
4888 When set to "once" the network operation will
4889 fail when all the available network interfaces
4890 are tried once without success.
4891 Useful on scripts which control the retry operation
4894 npe_ucode - set load address for the NPE microcode
4896 silent_linux - If set then linux will be told to boot silently, by
4897 changing the console to be empty. If "yes" it will be
4898 made silent. If "no" it will not be made silent. If
4899 unset, then it will be made silent if the U-Boot console
4902 tftpsrcport - If this is set, the value is used for TFTP's
4905 tftpdstport - If this is set, the value is used for TFTP's UDP
4906 destination port instead of the Well Know Port 69.
4908 tftpblocksize - Block size to use for TFTP transfers; if not set,
4909 we use the TFTP server's default block size
4911 tftptimeout - Retransmission timeout for TFTP packets (in milli-
4912 seconds, minimum value is 1000 = 1 second). Defines
4913 when a packet is considered to be lost so it has to
4914 be retransmitted. The default is 5000 = 5 seconds.
4915 Lowering this value may make downloads succeed
4916 faster in networks with high packet loss rates or
4917 with unreliable TFTP servers.
4919 vlan - When set to a value < 4095 the traffic over
4920 Ethernet is encapsulated/received over 802.1q
4923 The following image location variables contain the location of images
4924 used in booting. The "Image" column gives the role of the image and is
4925 not an environment variable name. The other columns are environment
4926 variable names. "File Name" gives the name of the file on a TFTP
4927 server, "RAM Address" gives the location in RAM the image will be
4928 loaded to, and "Flash Location" gives the image's address in NOR
4929 flash or offset in NAND flash.
4931 *Note* - these variables don't have to be defined for all boards, some
4932 boards currenlty use other variables for these purposes, and some
4933 boards use these variables for other purposes.
4935 Image File Name RAM Address Flash Location
4936 ----- --------- ----------- --------------
4937 u-boot u-boot u-boot_addr_r u-boot_addr
4938 Linux kernel bootfile kernel_addr_r kernel_addr
4939 device tree blob fdtfile fdt_addr_r fdt_addr
4940 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
4942 The following environment variables may be used and automatically
4943 updated by the network boot commands ("bootp" and "rarpboot"),
4944 depending the information provided by your boot server:
4946 bootfile - see above
4947 dnsip - IP address of your Domain Name Server
4948 dnsip2 - IP address of your secondary Domain Name Server
4949 gatewayip - IP address of the Gateway (Router) to use
4950 hostname - Target hostname
4952 netmask - Subnet Mask
4953 rootpath - Pathname of the root filesystem on the NFS server
4954 serverip - see above
4957 There are two special Environment Variables:
4959 serial# - contains hardware identification information such
4960 as type string and/or serial number
4961 ethaddr - Ethernet address
4963 These variables can be set only once (usually during manufacturing of
4964 the board). U-Boot refuses to delete or overwrite these variables
4965 once they have been set once.
4968 Further special Environment Variables:
4970 ver - Contains the U-Boot version string as printed
4971 with the "version" command. This variable is
4972 readonly (see CONFIG_VERSION_VARIABLE).
4975 Please note that changes to some configuration parameters may take
4976 only effect after the next boot (yes, that's just like Windoze :-).
4979 Callback functions for environment variables:
4980 ---------------------------------------------
4982 For some environment variables, the behavior of u-boot needs to change
4983 when their values are changed. This functionailty allows functions to
4984 be associated with arbitrary variables. On creation, overwrite, or
4985 deletion, the callback will provide the opportunity for some side
4986 effect to happen or for the change to be rejected.
4988 The callbacks are named and associated with a function using the
4989 U_BOOT_ENV_CALLBACK macro in your board or driver code.
4991 These callbacks are associated with variables in one of two ways. The
4992 static list can be added to by defining CONFIG_ENV_CALLBACK_LIST_STATIC
4993 in the board configuration to a string that defines a list of
4994 associations. The list must be in the following format:
4996 entry = variable_name[:callback_name]
4999 If the callback name is not specified, then the callback is deleted.
5000 Spaces are also allowed anywhere in the list.
5002 Callbacks can also be associated by defining the ".callbacks" variable
5003 with the same list format above. Any association in ".callbacks" will
5004 override any association in the static list. You can define
5005 CONFIG_ENV_CALLBACK_LIST_DEFAULT to a list (string) to define the
5006 ".callbacks" envirnoment variable in the default or embedded environment.
5009 Command Line Parsing:
5010 =====================
5012 There are two different command line parsers available with U-Boot:
5013 the old "simple" one, and the much more powerful "hush" shell:
5015 Old, simple command line parser:
5016 --------------------------------
5018 - supports environment variables (through setenv / saveenv commands)
5019 - several commands on one line, separated by ';'
5020 - variable substitution using "... ${name} ..." syntax
5021 - special characters ('$', ';') can be escaped by prefixing with '\',
5023 setenv bootcmd bootm \${address}
5024 - You can also escape text by enclosing in single apostrophes, for example:
5025 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
5030 - similar to Bourne shell, with control structures like
5031 if...then...else...fi, for...do...done; while...do...done,
5032 until...do...done, ...
5033 - supports environment ("global") variables (through setenv / saveenv
5034 commands) and local shell variables (through standard shell syntax
5035 "name=value"); only environment variables can be used with "run"
5041 (1) If a command line (or an environment variable executed by a "run"
5042 command) contains several commands separated by semicolon, and
5043 one of these commands fails, then the remaining commands will be
5046 (2) If you execute several variables with one call to run (i. e.
5047 calling run with a list of variables as arguments), any failing
5048 command will cause "run" to terminate, i. e. the remaining
5049 variables are not executed.
5051 Note for Redundant Ethernet Interfaces:
5052 =======================================
5054 Some boards come with redundant Ethernet interfaces; U-Boot supports
5055 such configurations and is capable of automatic selection of a
5056 "working" interface when needed. MAC assignment works as follows:
5058 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
5059 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
5060 "eth1addr" (=>eth1), "eth2addr", ...
5062 If the network interface stores some valid MAC address (for instance
5063 in SROM), this is used as default address if there is NO correspon-
5064 ding setting in the environment; if the corresponding environment
5065 variable is set, this overrides the settings in the card; that means:
5067 o If the SROM has a valid MAC address, and there is no address in the
5068 environment, the SROM's address is used.
5070 o If there is no valid address in the SROM, and a definition in the
5071 environment exists, then the value from the environment variable is
5074 o If both the SROM and the environment contain a MAC address, and
5075 both addresses are the same, this MAC address is used.
5077 o If both the SROM and the environment contain a MAC address, and the
5078 addresses differ, the value from the environment is used and a
5081 o If neither SROM nor the environment contain a MAC address, an error
5084 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
5085 will be programmed into hardware as part of the initialization process. This
5086 may be skipped by setting the appropriate 'ethmacskip' environment variable.
5087 The naming convention is as follows:
5088 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
5093 U-Boot is capable of booting (and performing other auxiliary operations on)
5094 images in two formats:
5096 New uImage format (FIT)
5097 -----------------------
5099 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
5100 to Flattened Device Tree). It allows the use of images with multiple
5101 components (several kernels, ramdisks, etc.), with contents protected by
5102 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
5108 Old image format is based on binary files which can be basically anything,
5109 preceded by a special header; see the definitions in include/image.h for
5110 details; basically, the header defines the following image properties:
5112 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
5113 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
5114 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
5115 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
5117 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
5118 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
5119 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
5120 * Compression Type (uncompressed, gzip, bzip2)
5126 The header is marked by a special Magic Number, and both the header
5127 and the data portions of the image are secured against corruption by
5134 Although U-Boot should support any OS or standalone application
5135 easily, the main focus has always been on Linux during the design of
5138 U-Boot includes many features that so far have been part of some
5139 special "boot loader" code within the Linux kernel. Also, any
5140 "initrd" images to be used are no longer part of one big Linux image;
5141 instead, kernel and "initrd" are separate images. This implementation
5142 serves several purposes:
5144 - the same features can be used for other OS or standalone
5145 applications (for instance: using compressed images to reduce the
5146 Flash memory footprint)
5148 - it becomes much easier to port new Linux kernel versions because
5149 lots of low-level, hardware dependent stuff are done by U-Boot
5151 - the same Linux kernel image can now be used with different "initrd"
5152 images; of course this also means that different kernel images can
5153 be run with the same "initrd". This makes testing easier (you don't
5154 have to build a new "zImage.initrd" Linux image when you just
5155 change a file in your "initrd"). Also, a field-upgrade of the
5156 software is easier now.
5162 Porting Linux to U-Boot based systems:
5163 ---------------------------------------
5165 U-Boot cannot save you from doing all the necessary modifications to
5166 configure the Linux device drivers for use with your target hardware
5167 (no, we don't intend to provide a full virtual machine interface to
5170 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
5172 Just make sure your machine specific header file (for instance
5173 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
5174 Information structure as we define in include/asm-<arch>/u-boot.h,
5175 and make sure that your definition of IMAP_ADDR uses the same value
5176 as your U-Boot configuration in CONFIG_SYS_IMMR.
5179 Configuring the Linux kernel:
5180 -----------------------------
5182 No specific requirements for U-Boot. Make sure you have some root
5183 device (initial ramdisk, NFS) for your target system.
5186 Building a Linux Image:
5187 -----------------------
5189 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
5190 not used. If you use recent kernel source, a new build target
5191 "uImage" will exist which automatically builds an image usable by
5192 U-Boot. Most older kernels also have support for a "pImage" target,
5193 which was introduced for our predecessor project PPCBoot and uses a
5194 100% compatible format.
5203 The "uImage" build target uses a special tool (in 'tools/mkimage') to
5204 encapsulate a compressed Linux kernel image with header information,
5205 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
5207 * build a standard "vmlinux" kernel image (in ELF binary format):
5209 * convert the kernel into a raw binary image:
5211 ${CROSS_COMPILE}-objcopy -O binary \
5212 -R .note -R .comment \
5213 -S vmlinux linux.bin
5215 * compress the binary image:
5219 * package compressed binary image for U-Boot:
5221 mkimage -A ppc -O linux -T kernel -C gzip \
5222 -a 0 -e 0 -n "Linux Kernel Image" \
5223 -d linux.bin.gz uImage
5226 The "mkimage" tool can also be used to create ramdisk images for use
5227 with U-Boot, either separated from the Linux kernel image, or
5228 combined into one file. "mkimage" encapsulates the images with a 64
5229 byte header containing information about target architecture,
5230 operating system, image type, compression method, entry points, time
5231 stamp, CRC32 checksums, etc.
5233 "mkimage" can be called in two ways: to verify existing images and
5234 print the header information, or to build new images.
5236 In the first form (with "-l" option) mkimage lists the information
5237 contained in the header of an existing U-Boot image; this includes
5238 checksum verification:
5240 tools/mkimage -l image
5241 -l ==> list image header information
5243 The second form (with "-d" option) is used to build a U-Boot image
5244 from a "data file" which is used as image payload:
5246 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
5247 -n name -d data_file image
5248 -A ==> set architecture to 'arch'
5249 -O ==> set operating system to 'os'
5250 -T ==> set image type to 'type'
5251 -C ==> set compression type 'comp'
5252 -a ==> set load address to 'addr' (hex)
5253 -e ==> set entry point to 'ep' (hex)
5254 -n ==> set image name to 'name'
5255 -d ==> use image data from 'datafile'
5257 Right now, all Linux kernels for PowerPC systems use the same load
5258 address (0x00000000), but the entry point address depends on the
5261 - 2.2.x kernels have the entry point at 0x0000000C,
5262 - 2.3.x and later kernels have the entry point at 0x00000000.
5264 So a typical call to build a U-Boot image would read:
5266 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5267 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
5268 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
5269 > examples/uImage.TQM850L
5270 Image Name: 2.4.4 kernel for TQM850L
5271 Created: Wed Jul 19 02:34:59 2000
5272 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5273 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5274 Load Address: 0x00000000
5275 Entry Point: 0x00000000
5277 To verify the contents of the image (or check for corruption):
5279 -> tools/mkimage -l examples/uImage.TQM850L
5280 Image Name: 2.4.4 kernel for TQM850L
5281 Created: Wed Jul 19 02:34:59 2000
5282 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5283 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
5284 Load Address: 0x00000000
5285 Entry Point: 0x00000000
5287 NOTE: for embedded systems where boot time is critical you can trade
5288 speed for memory and install an UNCOMPRESSED image instead: this
5289 needs more space in Flash, but boots much faster since it does not
5290 need to be uncompressed:
5292 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
5293 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
5294 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
5295 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
5296 > examples/uImage.TQM850L-uncompressed
5297 Image Name: 2.4.4 kernel for TQM850L
5298 Created: Wed Jul 19 02:34:59 2000
5299 Image Type: PowerPC Linux Kernel Image (uncompressed)
5300 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
5301 Load Address: 0x00000000
5302 Entry Point: 0x00000000
5305 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
5306 when your kernel is intended to use an initial ramdisk:
5308 -> tools/mkimage -n 'Simple Ramdisk Image' \
5309 > -A ppc -O linux -T ramdisk -C gzip \
5310 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
5311 Image Name: Simple Ramdisk Image
5312 Created: Wed Jan 12 14:01:50 2000
5313 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5314 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
5315 Load Address: 0x00000000
5316 Entry Point: 0x00000000
5318 The "dumpimage" is a tool to disassemble images built by mkimage. Its "-i"
5319 option performs the converse operation of the mkimage's second form (the "-d"
5320 option). Given an image built by mkimage, the dumpimage extracts a "data file"
5323 tools/dumpimage -i image -p position data_file
5324 -i ==> extract from the 'image' a specific 'data_file', \
5325 indexed by 'position'
5328 Installing a Linux Image:
5329 -------------------------
5331 To downloading a U-Boot image over the serial (console) interface,
5332 you must convert the image to S-Record format:
5334 objcopy -I binary -O srec examples/image examples/image.srec
5336 The 'objcopy' does not understand the information in the U-Boot
5337 image header, so the resulting S-Record file will be relative to
5338 address 0x00000000. To load it to a given address, you need to
5339 specify the target address as 'offset' parameter with the 'loads'
5342 Example: install the image to address 0x40100000 (which on the
5343 TQM8xxL is in the first Flash bank):
5345 => erase 40100000 401FFFFF
5351 ## Ready for S-Record download ...
5352 ~>examples/image.srec
5353 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
5355 15989 15990 15991 15992
5356 [file transfer complete]
5358 ## Start Addr = 0x00000000
5361 You can check the success of the download using the 'iminfo' command;
5362 this includes a checksum verification so you can be sure no data
5363 corruption happened:
5367 ## Checking Image at 40100000 ...
5368 Image Name: 2.2.13 for initrd on TQM850L
5369 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5370 Data Size: 335725 Bytes = 327 kB = 0 MB
5371 Load Address: 00000000
5372 Entry Point: 0000000c
5373 Verifying Checksum ... OK
5379 The "bootm" command is used to boot an application that is stored in
5380 memory (RAM or Flash). In case of a Linux kernel image, the contents
5381 of the "bootargs" environment variable is passed to the kernel as
5382 parameters. You can check and modify this variable using the
5383 "printenv" and "setenv" commands:
5386 => printenv bootargs
5387 bootargs=root=/dev/ram
5389 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5391 => printenv bootargs
5392 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5395 ## Booting Linux kernel at 40020000 ...
5396 Image Name: 2.2.13 for NFS on TQM850L
5397 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5398 Data Size: 381681 Bytes = 372 kB = 0 MB
5399 Load Address: 00000000
5400 Entry Point: 0000000c
5401 Verifying Checksum ... OK
5402 Uncompressing Kernel Image ... OK
5403 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
5404 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
5405 time_init: decrementer frequency = 187500000/60
5406 Calibrating delay loop... 49.77 BogoMIPS
5407 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
5410 If you want to boot a Linux kernel with initial RAM disk, you pass
5411 the memory addresses of both the kernel and the initrd image (PPBCOOT
5412 format!) to the "bootm" command:
5414 => imi 40100000 40200000
5416 ## Checking Image at 40100000 ...
5417 Image Name: 2.2.13 for initrd on TQM850L
5418 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5419 Data Size: 335725 Bytes = 327 kB = 0 MB
5420 Load Address: 00000000
5421 Entry Point: 0000000c
5422 Verifying Checksum ... OK
5424 ## Checking Image at 40200000 ...
5425 Image Name: Simple Ramdisk Image
5426 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5427 Data Size: 566530 Bytes = 553 kB = 0 MB
5428 Load Address: 00000000
5429 Entry Point: 00000000
5430 Verifying Checksum ... OK
5432 => bootm 40100000 40200000
5433 ## Booting Linux kernel at 40100000 ...
5434 Image Name: 2.2.13 for initrd on TQM850L
5435 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5436 Data Size: 335725 Bytes = 327 kB = 0 MB
5437 Load Address: 00000000
5438 Entry Point: 0000000c
5439 Verifying Checksum ... OK
5440 Uncompressing Kernel Image ... OK
5441 ## Loading RAMDisk Image at 40200000 ...
5442 Image Name: Simple Ramdisk Image
5443 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
5444 Data Size: 566530 Bytes = 553 kB = 0 MB
5445 Load Address: 00000000
5446 Entry Point: 00000000
5447 Verifying Checksum ... OK
5448 Loading Ramdisk ... OK
5449 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
5450 Boot arguments: root=/dev/ram
5451 time_init: decrementer frequency = 187500000/60
5452 Calibrating delay loop... 49.77 BogoMIPS
5454 RAMDISK: Compressed image found at block 0
5455 VFS: Mounted root (ext2 filesystem).
5459 Boot Linux and pass a flat device tree:
5462 First, U-Boot must be compiled with the appropriate defines. See the section
5463 titled "Linux Kernel Interface" above for a more in depth explanation. The
5464 following is an example of how to start a kernel and pass an updated
5470 oft=oftrees/mpc8540ads.dtb
5471 => tftp $oftaddr $oft
5472 Speed: 1000, full duplex
5474 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
5475 Filename 'oftrees/mpc8540ads.dtb'.
5476 Load address: 0x300000
5479 Bytes transferred = 4106 (100a hex)
5480 => tftp $loadaddr $bootfile
5481 Speed: 1000, full duplex
5483 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
5485 Load address: 0x200000
5486 Loading:############
5488 Bytes transferred = 1029407 (fb51f hex)
5493 => bootm $loadaddr - $oftaddr
5494 ## Booting image at 00200000 ...
5495 Image Name: Linux-2.6.17-dirty
5496 Image Type: PowerPC Linux Kernel Image (gzip compressed)
5497 Data Size: 1029343 Bytes = 1005.2 kB
5498 Load Address: 00000000
5499 Entry Point: 00000000
5500 Verifying Checksum ... OK
5501 Uncompressing Kernel Image ... OK
5502 Booting using flat device tree at 0x300000
5503 Using MPC85xx ADS machine description
5504 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
5508 More About U-Boot Image Types:
5509 ------------------------------
5511 U-Boot supports the following image types:
5513 "Standalone Programs" are directly runnable in the environment
5514 provided by U-Boot; it is expected that (if they behave
5515 well) you can continue to work in U-Boot after return from
5516 the Standalone Program.
5517 "OS Kernel Images" are usually images of some Embedded OS which
5518 will take over control completely. Usually these programs
5519 will install their own set of exception handlers, device
5520 drivers, set up the MMU, etc. - this means, that you cannot
5521 expect to re-enter U-Boot except by resetting the CPU.
5522 "RAMDisk Images" are more or less just data blocks, and their
5523 parameters (address, size) are passed to an OS kernel that is
5525 "Multi-File Images" contain several images, typically an OS
5526 (Linux) kernel image and one or more data images like
5527 RAMDisks. This construct is useful for instance when you want
5528 to boot over the network using BOOTP etc., where the boot
5529 server provides just a single image file, but you want to get
5530 for instance an OS kernel and a RAMDisk image.
5532 "Multi-File Images" start with a list of image sizes, each
5533 image size (in bytes) specified by an "uint32_t" in network
5534 byte order. This list is terminated by an "(uint32_t)0".
5535 Immediately after the terminating 0 follow the images, one by
5536 one, all aligned on "uint32_t" boundaries (size rounded up to
5537 a multiple of 4 bytes).
5539 "Firmware Images" are binary images containing firmware (like
5540 U-Boot or FPGA images) which usually will be programmed to
5543 "Script files" are command sequences that will be executed by
5544 U-Boot's command interpreter; this feature is especially
5545 useful when you configure U-Boot to use a real shell (hush)
5546 as command interpreter.
5548 Booting the Linux zImage:
5549 -------------------------
5551 On some platforms, it's possible to boot Linux zImage. This is done
5552 using the "bootz" command. The syntax of "bootz" command is the same
5553 as the syntax of "bootm" command.
5555 Note, defining the CONFIG_SUPPORT_RAW_INITRD allows user to supply
5556 kernel with raw initrd images. The syntax is slightly different, the
5557 address of the initrd must be augmented by it's size, in the following
5558 format: "<initrd addres>:<initrd size>".
5564 One of the features of U-Boot is that you can dynamically load and
5565 run "standalone" applications, which can use some resources of
5566 U-Boot like console I/O functions or interrupt services.
5568 Two simple examples are included with the sources:
5573 'examples/hello_world.c' contains a small "Hello World" Demo
5574 application; it is automatically compiled when you build U-Boot.
5575 It's configured to run at address 0x00040004, so you can play with it
5579 ## Ready for S-Record download ...
5580 ~>examples/hello_world.srec
5581 1 2 3 4 5 6 7 8 9 10 11 ...
5582 [file transfer complete]
5584 ## Start Addr = 0x00040004
5586 => go 40004 Hello World! This is a test.
5587 ## Starting application at 0x00040004 ...
5598 Hit any key to exit ...
5600 ## Application terminated, rc = 0x0
5602 Another example, which demonstrates how to register a CPM interrupt
5603 handler with the U-Boot code, can be found in 'examples/timer.c'.
5604 Here, a CPM timer is set up to generate an interrupt every second.
5605 The interrupt service routine is trivial, just printing a '.'
5606 character, but this is just a demo program. The application can be
5607 controlled by the following keys:
5609 ? - print current values og the CPM Timer registers
5610 b - enable interrupts and start timer
5611 e - stop timer and disable interrupts
5612 q - quit application
5615 ## Ready for S-Record download ...
5616 ~>examples/timer.srec
5617 1 2 3 4 5 6 7 8 9 10 11 ...
5618 [file transfer complete]
5620 ## Start Addr = 0x00040004
5623 ## Starting application at 0x00040004 ...
5626 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
5629 [q, b, e, ?] Set interval 1000000 us
5632 [q, b, e, ?] ........
5633 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
5636 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
5639 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
5642 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
5644 [q, b, e, ?] ...Stopping timer
5646 [q, b, e, ?] ## Application terminated, rc = 0x0
5652 Over time, many people have reported problems when trying to use the
5653 "minicom" terminal emulation program for serial download. I (wd)
5654 consider minicom to be broken, and recommend not to use it. Under
5655 Unix, I recommend to use C-Kermit for general purpose use (and
5656 especially for kermit binary protocol download ("loadb" command), and
5657 use "cu" for S-Record download ("loads" command). See
5658 http://www.denx.de/wiki/view/DULG/SystemSetup#Section_4.3.
5659 for help with kermit.
5662 Nevertheless, if you absolutely want to use it try adding this
5663 configuration to your "File transfer protocols" section:
5665 Name Program Name U/D FullScr IO-Red. Multi
5666 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
5667 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
5673 Starting at version 0.9.2, U-Boot supports NetBSD both as host
5674 (build U-Boot) and target system (boots NetBSD/mpc8xx).
5676 Building requires a cross environment; it is known to work on
5677 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
5678 need gmake since the Makefiles are not compatible with BSD make).
5679 Note that the cross-powerpc package does not install include files;
5680 attempting to build U-Boot will fail because <machine/ansi.h> is
5681 missing. This file has to be installed and patched manually:
5683 # cd /usr/pkg/cross/powerpc-netbsd/include
5685 # ln -s powerpc machine
5686 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
5687 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
5689 Native builds *don't* work due to incompatibilities between native
5690 and U-Boot include files.
5692 Booting assumes that (the first part of) the image booted is a
5693 stage-2 loader which in turn loads and then invokes the kernel
5694 proper. Loader sources will eventually appear in the NetBSD source
5695 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
5696 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
5699 Implementation Internals:
5700 =========================
5702 The following is not intended to be a complete description of every
5703 implementation detail. However, it should help to understand the
5704 inner workings of U-Boot and make it easier to port it to custom
5708 Initial Stack, Global Data:
5709 ---------------------------
5711 The implementation of U-Boot is complicated by the fact that U-Boot
5712 starts running out of ROM (flash memory), usually without access to
5713 system RAM (because the memory controller is not initialized yet).
5714 This means that we don't have writable Data or BSS segments, and BSS
5715 is not initialized as zero. To be able to get a C environment working
5716 at all, we have to allocate at least a minimal stack. Implementation
5717 options for this are defined and restricted by the CPU used: Some CPU
5718 models provide on-chip memory (like the IMMR area on MPC8xx and
5719 MPC826x processors), on others (parts of) the data cache can be
5720 locked as (mis-) used as memory, etc.
5722 Chris Hallinan posted a good summary of these issues to the
5723 U-Boot mailing list:
5725 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
5726 From: "Chris Hallinan" <clh@net1plus.com>
5727 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
5730 Correct me if I'm wrong, folks, but the way I understand it
5731 is this: Using DCACHE as initial RAM for Stack, etc, does not
5732 require any physical RAM backing up the cache. The cleverness
5733 is that the cache is being used as a temporary supply of
5734 necessary storage before the SDRAM controller is setup. It's
5735 beyond the scope of this list to explain the details, but you
5736 can see how this works by studying the cache architecture and
5737 operation in the architecture and processor-specific manuals.
5739 OCM is On Chip Memory, which I believe the 405GP has 4K. It
5740 is another option for the system designer to use as an
5741 initial stack/RAM area prior to SDRAM being available. Either
5742 option should work for you. Using CS 4 should be fine if your
5743 board designers haven't used it for something that would
5744 cause you grief during the initial boot! It is frequently not
5747 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
5748 with your processor/board/system design. The default value
5749 you will find in any recent u-boot distribution in
5750 walnut.h should work for you. I'd set it to a value larger
5751 than your SDRAM module. If you have a 64MB SDRAM module, set
5752 it above 400_0000. Just make sure your board has no resources
5753 that are supposed to respond to that address! That code in
5754 start.S has been around a while and should work as is when
5755 you get the config right.
5760 It is essential to remember this, since it has some impact on the C
5761 code for the initialization procedures:
5763 * Initialized global data (data segment) is read-only. Do not attempt
5766 * Do not use any uninitialized global data (or implicitely initialized
5767 as zero data - BSS segment) at all - this is undefined, initiali-
5768 zation is performed later (when relocating to RAM).
5770 * Stack space is very limited. Avoid big data buffers or things like
5773 Having only the stack as writable memory limits means we cannot use
5774 normal global data to share information beween the code. But it
5775 turned out that the implementation of U-Boot can be greatly
5776 simplified by making a global data structure (gd_t) available to all
5777 functions. We could pass a pointer to this data as argument to _all_
5778 functions, but this would bloat the code. Instead we use a feature of
5779 the GCC compiler (Global Register Variables) to share the data: we
5780 place a pointer (gd) to the global data into a register which we
5781 reserve for this purpose.
5783 When choosing a register for such a purpose we are restricted by the
5784 relevant (E)ABI specifications for the current architecture, and by
5785 GCC's implementation.
5787 For PowerPC, the following registers have specific use:
5789 R2: reserved for system use
5790 R3-R4: parameter passing and return values
5791 R5-R10: parameter passing
5792 R13: small data area pointer
5796 (U-Boot also uses R12 as internal GOT pointer. r12
5797 is a volatile register so r12 needs to be reset when
5798 going back and forth between asm and C)
5800 ==> U-Boot will use R2 to hold a pointer to the global data
5802 Note: on PPC, we could use a static initializer (since the
5803 address of the global data structure is known at compile time),
5804 but it turned out that reserving a register results in somewhat
5805 smaller code - although the code savings are not that big (on
5806 average for all boards 752 bytes for the whole U-Boot image,
5807 624 text + 127 data).
5809 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
5810 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
5812 ==> U-Boot will use P3 to hold a pointer to the global data
5814 On ARM, the following registers are used:
5816 R0: function argument word/integer result
5817 R1-R3: function argument word
5818 R9: platform specific
5819 R10: stack limit (used only if stack checking is enabled)
5820 R11: argument (frame) pointer
5821 R12: temporary workspace
5824 R15: program counter
5826 ==> U-Boot will use R9 to hold a pointer to the global data
5828 Note: on ARM, only R_ARM_RELATIVE relocations are supported.
5830 On Nios II, the ABI is documented here:
5831 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
5833 ==> U-Boot will use gp to hold a pointer to the global data
5835 Note: on Nios II, we give "-G0" option to gcc and don't use gp
5836 to access small data sections, so gp is free.
5838 On NDS32, the following registers are used:
5840 R0-R1: argument/return
5842 R15: temporary register for assembler
5843 R16: trampoline register
5844 R28: frame pointer (FP)
5845 R29: global pointer (GP)
5846 R30: link register (LP)
5847 R31: stack pointer (SP)
5848 PC: program counter (PC)
5850 ==> U-Boot will use R10 to hold a pointer to the global data
5852 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
5853 or current versions of GCC may "optimize" the code too much.
5858 U-Boot runs in system state and uses physical addresses, i.e. the
5859 MMU is not used either for address mapping nor for memory protection.
5861 The available memory is mapped to fixed addresses using the memory
5862 controller. In this process, a contiguous block is formed for each
5863 memory type (Flash, SDRAM, SRAM), even when it consists of several
5864 physical memory banks.
5866 U-Boot is installed in the first 128 kB of the first Flash bank (on
5867 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
5868 booting and sizing and initializing DRAM, the code relocates itself
5869 to the upper end of DRAM. Immediately below the U-Boot code some
5870 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
5871 configuration setting]. Below that, a structure with global Board
5872 Info data is placed, followed by the stack (growing downward).
5874 Additionally, some exception handler code is copied to the low 8 kB
5875 of DRAM (0x00000000 ... 0x00001FFF).
5877 So a typical memory configuration with 16 MB of DRAM could look like
5880 0x0000 0000 Exception Vector code
5883 0x0000 2000 Free for Application Use
5889 0x00FB FF20 Monitor Stack (Growing downward)
5890 0x00FB FFAC Board Info Data and permanent copy of global data
5891 0x00FC 0000 Malloc Arena
5894 0x00FE 0000 RAM Copy of Monitor Code
5895 ... eventually: LCD or video framebuffer
5896 ... eventually: pRAM (Protected RAM - unchanged by reset)
5897 0x00FF FFFF [End of RAM]
5900 System Initialization:
5901 ----------------------
5903 In the reset configuration, U-Boot starts at the reset entry point
5904 (on most PowerPC systems at address 0x00000100). Because of the reset
5905 configuration for CS0# this is a mirror of the onboard Flash memory.
5906 To be able to re-map memory U-Boot then jumps to its link address.
5907 To be able to implement the initialization code in C, a (small!)
5908 initial stack is set up in the internal Dual Ported RAM (in case CPUs
5909 which provide such a feature like MPC8xx or MPC8260), or in a locked
5910 part of the data cache. After that, U-Boot initializes the CPU core,
5911 the caches and the SIU.
5913 Next, all (potentially) available memory banks are mapped using a
5914 preliminary mapping. For example, we put them on 512 MB boundaries
5915 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
5916 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
5917 programmed for SDRAM access. Using the temporary configuration, a
5918 simple memory test is run that determines the size of the SDRAM
5921 When there is more than one SDRAM bank, and the banks are of
5922 different size, the largest is mapped first. For equal size, the first
5923 bank (CS2#) is mapped first. The first mapping is always for address
5924 0x00000000, with any additional banks following immediately to create
5925 contiguous memory starting from 0.
5927 Then, the monitor installs itself at the upper end of the SDRAM area
5928 and allocates memory for use by malloc() and for the global Board
5929 Info data; also, the exception vector code is copied to the low RAM
5930 pages, and the final stack is set up.
5932 Only after this relocation will you have a "normal" C environment;
5933 until that you are restricted in several ways, mostly because you are
5934 running from ROM, and because the code will have to be relocated to a
5938 U-Boot Porting Guide:
5939 ----------------------
5941 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
5945 int main(int argc, char *argv[])
5947 sighandler_t no_more_time;
5949 signal(SIGALRM, no_more_time);
5950 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
5952 if (available_money > available_manpower) {
5953 Pay consultant to port U-Boot;
5957 Download latest U-Boot source;
5959 Subscribe to u-boot mailing list;
5962 email("Hi, I am new to U-Boot, how do I get started?");
5965 Read the README file in the top level directory;
5966 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
5967 Read applicable doc/*.README;
5968 Read the source, Luke;
5969 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
5972 if (available_money > toLocalCurrency ($2500))
5975 Add a lot of aggravation and time;
5977 if (a similar board exists) { /* hopefully... */
5978 cp -a board/<similar> board/<myboard>
5979 cp include/configs/<similar>.h include/configs/<myboard>.h
5981 Create your own board support subdirectory;
5982 Create your own board include/configs/<myboard>.h file;
5984 Edit new board/<myboard> files
5985 Edit new include/configs/<myboard>.h
5990 Add / modify source code;
5994 email("Hi, I am having problems...");
5996 Send patch file to the U-Boot email list;
5997 if (reasonable critiques)
5998 Incorporate improvements from email list code review;
6000 Defend code as written;
6006 void no_more_time (int sig)
6015 All contributions to U-Boot should conform to the Linux kernel
6016 coding style; see the file "Documentation/CodingStyle" and the script
6017 "scripts/Lindent" in your Linux kernel source directory.
6019 Source files originating from a different project (for example the
6020 MTD subsystem) are generally exempt from these guidelines and are not
6021 reformated to ease subsequent migration to newer versions of those
6024 Please note that U-Boot is implemented in C (and to some small parts in
6025 Assembler); no C++ is used, so please do not use C++ style comments (//)
6028 Please also stick to the following formatting rules:
6029 - remove any trailing white space
6030 - use TAB characters for indentation and vertical alignment, not spaces
6031 - make sure NOT to use DOS '\r\n' line feeds
6032 - do not add more than 2 consecutive empty lines to source files
6033 - do not add trailing empty lines to source files
6035 Submissions which do not conform to the standards may be returned
6036 with a request to reformat the changes.
6042 Since the number of patches for U-Boot is growing, we need to
6043 establish some rules. Submissions which do not conform to these rules
6044 may be rejected, even when they contain important and valuable stuff.
6046 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
6048 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
6049 see http://lists.denx.de/mailman/listinfo/u-boot
6051 When you send a patch, please include the following information with
6054 * For bug fixes: a description of the bug and how your patch fixes
6055 this bug. Please try to include a way of demonstrating that the
6056 patch actually fixes something.
6058 * For new features: a description of the feature and your
6061 * A CHANGELOG entry as plaintext (separate from the patch)
6063 * For major contributions, your entry to the CREDITS file
6065 * When you add support for a new board, don't forget to add a
6066 maintainer e-mail address to the boards.cfg file, too.
6068 * If your patch adds new configuration options, don't forget to
6069 document these in the README file.
6071 * The patch itself. If you are using git (which is *strongly*
6072 recommended) you can easily generate the patch using the
6073 "git format-patch". If you then use "git send-email" to send it to
6074 the U-Boot mailing list, you will avoid most of the common problems
6075 with some other mail clients.
6077 If you cannot use git, use "diff -purN OLD NEW". If your version of
6078 diff does not support these options, then get the latest version of
6081 The current directory when running this command shall be the parent
6082 directory of the U-Boot source tree (i. e. please make sure that
6083 your patch includes sufficient directory information for the
6086 We prefer patches as plain text. MIME attachments are discouraged,
6087 and compressed attachments must not be used.
6089 * If one logical set of modifications affects or creates several
6090 files, all these changes shall be submitted in a SINGLE patch file.
6092 * Changesets that contain different, unrelated modifications shall be
6093 submitted as SEPARATE patches, one patch per changeset.
6098 * Before sending the patch, run the MAKEALL script on your patched
6099 source tree and make sure that no errors or warnings are reported
6100 for any of the boards.
6102 * Keep your modifications to the necessary minimum: A patch
6103 containing several unrelated changes or arbitrary reformats will be
6104 returned with a request to re-formatting / split it.
6106 * If you modify existing code, make sure that your new code does not
6107 add to the memory footprint of the code ;-) Small is beautiful!
6108 When adding new features, these should compile conditionally only
6109 (using #ifdef), and the resulting code with the new feature
6110 disabled must not need more memory than the old code without your
6113 * Remember that there is a size limit of 100 kB per message on the
6114 u-boot mailing list. Bigger patches will be moderated. If they are
6115 reasonable and not too big, they will be acknowledged. But patches
6116 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob