2 # (C) Copyright 2000 - 2011
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC, ARM, MIPS and several other
29 processors, which can be installed in a boot ROM and used to
30 initialize and test the hardware or to download and run application
33 The development of U-Boot is closely related to Linux: some parts of
34 the source code originate in the Linux source tree, we have some
35 header files in common, and special provision has been made to
36 support booting of Linux images.
38 Some attention has been paid to make this software easily
39 configurable and extendable. For instance, all monitor commands are
40 implemented with the same call interface, so that it's very easy to
41 add new commands. Also, instead of permanently adding rarely used
42 code (for instance hardware test utilities) to the monitor, you can
43 load and run it dynamically.
49 In general, all boards for which a configuration option exists in the
50 Makefile have been tested to some extent and can be considered
51 "working". In fact, many of them are used in production systems.
53 In case of problems see the CHANGELOG and CREDITS files to find out
54 who contributed the specific port. The MAINTAINERS file lists board
61 In case you have questions about, problems with or contributions for
62 U-Boot you should send a message to the U-Boot mailing list at
63 <u-boot@lists.denx.de>. There is also an archive of previous traffic
64 on the mailing list - please search the archive before asking FAQ's.
65 Please see http://lists.denx.de/pipermail/u-boot and
66 http://dir.gmane.org/gmane.comp.boot-loaders.u-boot
69 Where to get source code:
70 =========================
72 The U-Boot source code is maintained in the git repository at
73 git://www.denx.de/git/u-boot.git ; you can browse it online at
74 http://www.denx.de/cgi-bin/gitweb.cgi?p=u-boot.git;a=summary
76 The "snapshot" links on this page allow you to download tarballs of
77 any version you might be interested in. Official releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
91 - make it easier to add custom boards
92 - make it possible to add other [PowerPC] CPUs
93 - extend functions, especially:
94 * Provide extended interface to Linux boot loader
97 * PCMCIA / CompactFlash / ATA disk / SCSI ... boot
98 - create ARMBoot project (http://sourceforge.net/projects/armboot)
99 - add other CPU families (starting with ARM)
100 - create U-Boot project (http://sourceforge.net/projects/u-boot)
101 - current project page: see http://www.denx.de/wiki/U-Boot
107 The "official" name of this project is "Das U-Boot". The spelling
108 "U-Boot" shall be used in all written text (documentation, comments
109 in source files etc.). Example:
111 This is the README file for the U-Boot project.
113 File names etc. shall be based on the string "u-boot". Examples:
115 include/asm-ppc/u-boot.h
117 #include <asm/u-boot.h>
119 Variable names, preprocessor constants etc. shall be either based on
120 the string "u_boot" or on "U_BOOT". Example:
122 U_BOOT_VERSION u_boot_logo
123 IH_OS_U_BOOT u_boot_hush_start
129 Starting with the release in October 2008, the names of the releases
130 were changed from numerical release numbers without deeper meaning
131 into a time stamp based numbering. Regular releases are identified by
132 names consisting of the calendar year and month of the release date.
133 Additional fields (if present) indicate release candidates or bug fix
134 releases in "stable" maintenance trees.
137 U-Boot v2009.11 - Release November 2009
138 U-Boot v2009.11.1 - Release 1 in version November 2009 stable tree
139 U-Boot v2010.09-rc1 - Release candiate 1 for September 2010 release
145 /arch Architecture specific files
146 /arm Files generic to ARM architecture
147 /cpu CPU specific files
148 /arm720t Files specific to ARM 720 CPUs
149 /arm920t Files specific to ARM 920 CPUs
150 /at91 Files specific to Atmel AT91RM9200 CPU
151 /imx Files specific to Freescale MC9328 i.MX CPUs
152 /s3c24x0 Files specific to Samsung S3C24X0 CPUs
153 /arm925t Files specific to ARM 925 CPUs
154 /arm926ejs Files specific to ARM 926 CPUs
155 /arm1136 Files specific to ARM 1136 CPUs
156 /ixp Files specific to Intel XScale IXP CPUs
157 /pxa Files specific to Intel XScale PXA CPUs
158 /s3c44b0 Files specific to Samsung S3C44B0 CPUs
159 /sa1100 Files specific to Intel StrongARM SA1100 CPUs
160 /lib Architecture specific library files
161 /avr32 Files generic to AVR32 architecture
162 /cpu CPU specific files
163 /lib Architecture specific library files
164 /blackfin Files generic to Analog Devices Blackfin architecture
165 /cpu CPU specific files
166 /lib Architecture specific library files
167 /x86 Files generic to x86 architecture
168 /cpu CPU specific files
169 /lib Architecture specific library files
170 /m68k Files generic to m68k architecture
171 /cpu CPU specific files
172 /mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
173 /mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
174 /mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
175 /mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
176 /mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
177 /lib Architecture specific library files
178 /microblaze Files generic to microblaze architecture
179 /cpu CPU specific files
180 /lib Architecture specific library files
181 /mips Files generic to MIPS architecture
182 /cpu CPU specific files
183 /mips32 Files specific to MIPS32 CPUs
184 /xburst Files specific to Ingenic XBurst CPUs
185 /lib Architecture specific library files
186 /nds32 Files generic to NDS32 architecture
187 /cpu CPU specific files
188 /n1213 Files specific to Andes Technology N1213 CPUs
189 /lib Architecture specific library files
190 /nios2 Files generic to Altera NIOS2 architecture
191 /cpu CPU specific files
192 /lib Architecture specific library files
193 /powerpc Files generic to PowerPC architecture
194 /cpu CPU specific files
195 /74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
196 /mpc5xx Files specific to Freescale MPC5xx CPUs
197 /mpc5xxx Files specific to Freescale MPC5xxx CPUs
198 /mpc8xx Files specific to Freescale MPC8xx CPUs
199 /mpc8220 Files specific to Freescale MPC8220 CPUs
200 /mpc824x Files specific to Freescale MPC824x CPUs
201 /mpc8260 Files specific to Freescale MPC8260 CPUs
202 /mpc85xx Files specific to Freescale MPC85xx CPUs
203 /ppc4xx Files specific to AMCC PowerPC 4xx CPUs
204 /lib Architecture specific library files
205 /sh Files generic to SH architecture
206 /cpu CPU specific files
207 /sh2 Files specific to sh2 CPUs
208 /sh3 Files specific to sh3 CPUs
209 /sh4 Files specific to sh4 CPUs
210 /lib Architecture specific library files
211 /sparc Files generic to SPARC architecture
212 /cpu CPU specific files
213 /leon2 Files specific to Gaisler LEON2 SPARC CPU
214 /leon3 Files specific to Gaisler LEON3 SPARC CPU
215 /lib Architecture specific library files
216 /api Machine/arch independent API for external apps
217 /board Board dependent files
218 /common Misc architecture independent functions
219 /disk Code for disk drive partition handling
220 /doc Documentation (don't expect too much)
221 /drivers Commonly used device drivers
222 /examples Example code for standalone applications, etc.
223 /fs Filesystem code (cramfs, ext2, jffs2, etc.)
224 /include Header Files
225 /lib Files generic to all architectures
226 /libfdt Library files to support flattened device trees
227 /lzma Library files to support LZMA decompression
228 /lzo Library files to support LZO decompression
230 /post Power On Self Test
231 /rtc Real Time Clock drivers
232 /tools Tools to build S-Record or U-Boot images, etc.
234 Software Configuration:
235 =======================
237 Configuration is usually done using C preprocessor defines; the
238 rationale behind that is to avoid dead code whenever possible.
240 There are two classes of configuration variables:
242 * Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
246 * Configuration _SETTINGS_:
247 These depend on the hardware etc. and should not be meddled with if
248 you don't know what you're doing; they have names beginning with
251 Later we will add a configuration tool - probably similar to or even
252 identical to what's used for the Linux kernel. Right now, we have to
253 do the configuration by hand, which means creating some symbolic
254 links and editing some configuration files. We use the TQM8xxL boards
258 Selection of Processor Architecture and Board Type:
259 ---------------------------------------------------
261 For all supported boards there are ready-to-use default
262 configurations available; just type "make <board_name>_config".
264 Example: For a TQM823L module type:
269 For the Cogent platform, you need to specify the CPU type as well;
270 e.g. "make cogent_mpc8xx_config". And also configure the cogent
271 directory according to the instructions in cogent/README.
274 Configuration Options:
275 ----------------------
277 Configuration depends on the combination of board and CPU type; all
278 such information is kept in a configuration file
279 "include/configs/<board_name>.h".
281 Example: For a TQM823L module, all configuration settings are in
282 "include/configs/TQM823L.h".
285 Many of the options are named exactly as the corresponding Linux
286 kernel configuration options. The intention is to make it easier to
287 build a config tool - later.
290 The following options need to be configured:
292 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
294 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
296 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
297 Define exactly one, e.g. CONFIG_ATSTK1002
299 - CPU Module Type: (if CONFIG_COGENT is defined)
300 Define exactly one of
302 --- FIXME --- not tested yet:
303 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
304 CONFIG_CMA287_23, CONFIG_CMA287_50
306 - Motherboard Type: (if CONFIG_COGENT is defined)
307 Define exactly one of
308 CONFIG_CMA101, CONFIG_CMA102
310 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
311 Define one or more of
314 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
315 Define one or more of
316 CONFIG_LCD_HEARTBEAT - update a character position on
317 the LCD display every second with
320 - Board flavour: (if CONFIG_MPC8260ADS is defined)
323 CONFIG_SYS_8260ADS - original MPC8260ADS
324 CONFIG_SYS_8266ADS - MPC8266ADS
325 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
326 CONFIG_SYS_8272ADS - MPC8272ADS
328 - Marvell Family Member
329 CONFIG_SYS_MVFS - define it if you want to enable
330 multiple fs option at one time
331 for marvell soc family
333 - MPC824X Family Member (if CONFIG_MPC824X is defined)
334 Define exactly one of
335 CONFIG_MPC8240, CONFIG_MPC8245
337 - 8xx CPU Options: (if using an MPC8xx CPU)
338 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
339 get_gclk_freq() cannot work
340 e.g. if there is no 32KHz
341 reference PIT/RTC clock
342 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
345 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
346 CONFIG_SYS_8xx_CPUCLK_MIN
347 CONFIG_SYS_8xx_CPUCLK_MAX
348 CONFIG_8xx_CPUCLK_DEFAULT
349 See doc/README.MPC866
351 CONFIG_SYS_MEASURE_CPUCLK
353 Define this to measure the actual CPU clock instead
354 of relying on the correctness of the configured
355 values. Mostly useful for board bringup to make sure
356 the PLL is locked at the intended frequency. Note
357 that this requires a (stable) reference clock (32 kHz
358 RTC clock or CONFIG_SYS_8XX_XIN)
360 CONFIG_SYS_DELAYED_ICACHE
362 Define this option if you want to enable the
363 ICache only when Code runs from RAM.
366 CONFIG_SYS_FSL_TBCLK_DIV
368 Defines the core time base clock divider ratio compared to the
369 system clock. On most PQ3 devices this is 8, on newer QorIQ
370 devices it can be 16 or 32. The ratio varies from SoC to Soc.
372 CONFIG_SYS_FSL_PCIE_COMPAT
374 Defines the string to utilize when trying to match PCIe device
375 tree nodes for the given platform.
377 - Intel Monahans options:
378 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
380 Defines the Monahans run mode to oscillator
381 ratio. Valid values are 8, 16, 24, 31. The core
382 frequency is this value multiplied by 13 MHz.
384 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
386 Defines the Monahans turbo mode to oscillator
387 ratio. Valid values are 1 (default if undefined) and
388 2. The core frequency as calculated above is multiplied
392 CONFIG_SYS_INIT_SP_OFFSET
394 Offset relative to CONFIG_SYS_SDRAM_BASE for initial stack
395 pointer. This is needed for the temporary stack before
398 CONFIG_SYS_MIPS_CACHE_MODE
400 Cache operation mode for the MIPS CPU.
401 See also arch/mips/include/asm/mipsregs.h.
403 CONF_CM_CACHABLE_NO_WA
406 CONF_CM_CACHABLE_NONCOHERENT
410 CONF_CM_CACHABLE_ACCELERATED
412 CONFIG_SYS_XWAY_EBU_BOOTCFG
414 Special option for Lantiq XWAY SoCs for booting from NOR flash.
415 See also arch/mips/cpu/mips32/start.S.
417 CONFIG_XWAY_SWAP_BYTES
419 Enable compilation of tools/xway-swap-bytes needed for Lantiq
420 XWAY SoCs for booting from NOR flash. The U-Boot image needs to
421 be swapped if a flash programmer is used.
423 - Linux Kernel Interface:
426 U-Boot stores all clock information in Hz
427 internally. For binary compatibility with older Linux
428 kernels (which expect the clocks passed in the
429 bd_info data to be in MHz) the environment variable
430 "clocks_in_mhz" can be defined so that U-Boot
431 converts clock data to MHZ before passing it to the
433 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
434 "clocks_in_mhz=1" is automatically included in the
437 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
439 When transferring memsize parameter to linux, some versions
440 expect it to be in bytes, others in MB.
441 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
445 New kernel versions are expecting firmware settings to be
446 passed using flattened device trees (based on open firmware
450 * New libfdt-based support
451 * Adds the "fdt" command
452 * The bootm command automatically updates the fdt
454 OF_CPU - The proper name of the cpus node (only required for
455 MPC512X and MPC5xxx based boards).
456 OF_SOC - The proper name of the soc node (only required for
457 MPC512X and MPC5xxx based boards).
458 OF_TBCLK - The timebase frequency.
459 OF_STDOUT_PATH - The path to the console device
461 boards with QUICC Engines require OF_QE to set UCC MAC
464 CONFIG_OF_BOARD_SETUP
466 Board code has addition modification that it wants to make
467 to the flat device tree before handing it off to the kernel
471 This define fills in the correct boot CPU in the boot
472 param header, the default value is zero if undefined.
476 U-Boot can detect if an IDE device is present or not.
477 If not, and this new config option is activated, U-Boot
478 removes the ATA node from the DTS before booting Linux,
479 so the Linux IDE driver does not probe the device and
480 crash. This is needed for buggy hardware (uc101) where
481 no pull down resistor is connected to the signal IDE5V_DD7.
483 CONFIG_MACH_TYPE [relevant for ARM only][mandatory]
485 This setting is mandatory for all boards that have only one
486 machine type and must be used to specify the machine type
487 number as it appears in the ARM machine registry
488 (see http://www.arm.linux.org.uk/developer/machines/).
489 Only boards that have multiple machine types supported
490 in a single configuration file and the machine type is
491 runtime discoverable, do not have to use this setting.
493 - vxWorks boot parameters:
495 bootvx constructs a valid bootline using the following
496 environments variables: bootfile, ipaddr, serverip, hostname.
497 It loads the vxWorks image pointed bootfile.
499 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
500 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
501 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
502 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
504 CONFIG_SYS_VXWORKS_ADD_PARAMS
506 Add it at the end of the bootline. E.g "u=username pw=secret"
508 Note: If a "bootargs" environment is defined, it will overwride
509 the defaults discussed just above.
511 - Cache Configuration:
512 CONFIG_SYS_ICACHE_OFF - Do not enable instruction cache in U-Boot
513 CONFIG_SYS_DCACHE_OFF - Do not enable data cache in U-Boot
514 CONFIG_SYS_L2CACHE_OFF- Do not enable L2 cache in U-Boot
516 - Cache Configuration for ARM:
517 CONFIG_SYS_L2_PL310 - Enable support for ARM PL310 L2 cache
519 CONFIG_SYS_PL310_BASE - Physical base address of PL310
520 controller register space
525 Define this if you want support for Amba PrimeCell PL010 UARTs.
529 Define this if you want support for Amba PrimeCell PL011 UARTs.
533 If you have Amba PrimeCell PL011 UARTs, set this variable to
534 the clock speed of the UARTs.
538 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
539 define this to a list of base addresses for each (supported)
540 port. See e.g. include/configs/versatile.h
542 CONFIG_PL011_SERIAL_RLCR
544 Some vendor versions of PL011 serial ports (e.g. ST-Ericsson U8500)
545 have separate receive and transmit line control registers. Set
546 this variable to initialize the extra register.
548 CONFIG_PL011_SERIAL_FLUSH_ON_INIT
550 On some platforms (e.g. U8500) U-Boot is loaded by a second stage
551 boot loader that has already initialized the UART. Define this
552 variable to flush the UART at init time.
556 Depending on board, define exactly one serial port
557 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
558 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
559 console by defining CONFIG_8xx_CONS_NONE
561 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
562 port routines must be defined elsewhere
563 (i.e. serial_init(), serial_getc(), ...)
566 Enables console device for a color framebuffer. Needs following
567 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
568 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
570 VIDEO_HW_RECTFILL graphic chip supports
573 VIDEO_HW_BITBLT graphic chip supports
574 bit-blit (cf. smiLynxEM)
575 VIDEO_VISIBLE_COLS visible pixel columns
577 VIDEO_VISIBLE_ROWS visible pixel rows
578 VIDEO_PIXEL_SIZE bytes per pixel
579 VIDEO_DATA_FORMAT graphic data format
580 (0-5, cf. cfb_console.c)
581 VIDEO_FB_ADRS framebuffer address
582 VIDEO_KBD_INIT_FCT keyboard int fct
583 (i.e. i8042_kbd_init())
584 VIDEO_TSTC_FCT test char fct
586 VIDEO_GETC_FCT get char fct
588 CONFIG_CONSOLE_CURSOR cursor drawing on/off
589 (requires blink timer
591 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
592 CONFIG_CONSOLE_TIME display time/date info in
594 (requires CONFIG_CMD_DATE)
595 CONFIG_VIDEO_LOGO display Linux logo in
597 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
598 linux_logo.h for logo.
599 Requires CONFIG_VIDEO_LOGO
600 CONFIG_CONSOLE_EXTRA_INFO
601 additional board info beside
604 When CONFIG_CFB_CONSOLE is defined, video console is
605 default i/o. Serial console can be forced with
606 environment 'console=serial'.
608 When CONFIG_SILENT_CONSOLE is defined, all console
609 messages (by U-Boot and Linux!) can be silenced with
610 the "silent" environment variable. See
611 doc/README.silent for more information.
614 CONFIG_BAUDRATE - in bps
615 Select one of the baudrates listed in
616 CONFIG_SYS_BAUDRATE_TABLE, see below.
617 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
619 - Console Rx buffer length
620 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
621 the maximum receive buffer length for the SMC.
622 This option is actual only for 82xx and 8xx possible.
623 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
624 must be defined, to setup the maximum idle timeout for
627 - Pre-Console Buffer:
628 Prior to the console being initialised (i.e. serial UART
629 initialised etc) all console output is silently discarded.
630 Defining CONFIG_PRE_CONSOLE_BUFFER will cause U-Boot to
631 buffer any console messages prior to the console being
632 initialised to a buffer of size CONFIG_PRE_CON_BUF_SZ
633 bytes located at CONFIG_PRE_CON_BUF_ADDR. The buffer is
634 a circular buffer, so if more than CONFIG_PRE_CON_BUF_SZ
635 bytes are output before the console is initialised, the
636 earlier bytes are discarded.
638 'Sane' compilers will generate smaller code if
639 CONFIG_PRE_CON_BUF_SZ is a power of 2
641 - Boot Delay: CONFIG_BOOTDELAY - in seconds
642 Delay before automatically booting the default image;
643 set to -1 to disable autoboot.
645 See doc/README.autoboot for these options that
646 work with CONFIG_BOOTDELAY. None are required.
647 CONFIG_BOOT_RETRY_TIME
648 CONFIG_BOOT_RETRY_MIN
649 CONFIG_AUTOBOOT_KEYED
650 CONFIG_AUTOBOOT_PROMPT
651 CONFIG_AUTOBOOT_DELAY_STR
652 CONFIG_AUTOBOOT_STOP_STR
653 CONFIG_AUTOBOOT_DELAY_STR2
654 CONFIG_AUTOBOOT_STOP_STR2
655 CONFIG_ZERO_BOOTDELAY_CHECK
656 CONFIG_RESET_TO_RETRY
660 Only needed when CONFIG_BOOTDELAY is enabled;
661 define a command string that is automatically executed
662 when no character is read on the console interface
663 within "Boot Delay" after reset.
666 This can be used to pass arguments to the bootm
667 command. The value of CONFIG_BOOTARGS goes into the
668 environment value "bootargs".
670 CONFIG_RAMBOOT and CONFIG_NFSBOOT
671 The value of these goes into the environment as
672 "ramboot" and "nfsboot" respectively, and can be used
673 as a convenience, when switching between booting from
679 When this option is #defined, the existence of the
680 environment variable "preboot" will be checked
681 immediately before starting the CONFIG_BOOTDELAY
682 countdown and/or running the auto-boot command resp.
683 entering interactive mode.
685 This feature is especially useful when "preboot" is
686 automatically generated or modified. For an example
687 see the LWMON board specific code: here "preboot" is
688 modified when the user holds down a certain
689 combination of keys on the (special) keyboard when
692 - Serial Download Echo Mode:
694 If defined to 1, all characters received during a
695 serial download (using the "loads" command) are
696 echoed back. This might be needed by some terminal
697 emulations (like "cu"), but may as well just take
698 time on others. This setting #define's the initial
699 value of the "loads_echo" environment variable.
701 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
703 Select one of the baudrates listed in
704 CONFIG_SYS_BAUDRATE_TABLE, see below.
707 Monitor commands can be included or excluded
708 from the build by using the #include files
709 "config_cmd_all.h" and #undef'ing unwanted
710 commands, or using "config_cmd_default.h"
711 and augmenting with additional #define's
714 The default command configuration includes all commands
715 except those marked below with a "*".
717 CONFIG_CMD_ASKENV * ask for env variable
718 CONFIG_CMD_BDI bdinfo
719 CONFIG_CMD_BEDBUG * Include BedBug Debugger
720 CONFIG_CMD_BMP * BMP support
721 CONFIG_CMD_BSP * Board specific commands
722 CONFIG_CMD_BOOTD bootd
723 CONFIG_CMD_CACHE * icache, dcache
724 CONFIG_CMD_CONSOLE coninfo
725 CONFIG_CMD_CRC32 * crc32
726 CONFIG_CMD_DATE * support for RTC, date/time...
727 CONFIG_CMD_DHCP * DHCP support
728 CONFIG_CMD_DIAG * Diagnostics
729 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
730 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
731 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
732 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
733 CONFIG_CMD_DTT * Digital Therm and Thermostat
734 CONFIG_CMD_ECHO echo arguments
735 CONFIG_CMD_EDITENV edit env variable
736 CONFIG_CMD_EEPROM * EEPROM read/write support
737 CONFIG_CMD_ELF * bootelf, bootvx
738 CONFIG_CMD_EXPORTENV * export the environment
739 CONFIG_CMD_SAVEENV saveenv
740 CONFIG_CMD_FDC * Floppy Disk Support
741 CONFIG_CMD_FAT * FAT partition support
742 CONFIG_CMD_FDOS * Dos diskette Support
743 CONFIG_CMD_FLASH flinfo, erase, protect
744 CONFIG_CMD_FPGA FPGA device initialization support
745 CONFIG_CMD_GO * the 'go' command (exec code)
746 CONFIG_CMD_GREPENV * search environment
747 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
748 CONFIG_CMD_I2C * I2C serial bus support
749 CONFIG_CMD_IDE * IDE harddisk support
750 CONFIG_CMD_IMI iminfo
751 CONFIG_CMD_IMLS List all found images
752 CONFIG_CMD_IMMAP * IMMR dump support
753 CONFIG_CMD_IMPORTENV * import an environment
754 CONFIG_CMD_IRQ * irqinfo
755 CONFIG_CMD_ITEST Integer/string test of 2 values
756 CONFIG_CMD_JFFS2 * JFFS2 Support
757 CONFIG_CMD_KGDB * kgdb
758 CONFIG_CMD_LDRINFO ldrinfo (display Blackfin loader)
759 CONFIG_CMD_LOADB loadb
760 CONFIG_CMD_LOADS loads
761 CONFIG_CMD_MD5SUM print md5 message digest
762 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
763 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
765 CONFIG_CMD_MISC Misc functions like sleep etc
766 CONFIG_CMD_MMC * MMC memory mapped support
767 CONFIG_CMD_MII * MII utility commands
768 CONFIG_CMD_MTDPARTS * MTD partition support
769 CONFIG_CMD_NAND * NAND support
770 CONFIG_CMD_NET bootp, tftpboot, rarpboot
771 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
772 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
773 CONFIG_CMD_PCI * pciinfo
774 CONFIG_CMD_PCMCIA * PCMCIA support
775 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
777 CONFIG_CMD_PORTIO * Port I/O
778 CONFIG_CMD_REGINFO * Register dump
779 CONFIG_CMD_RUN run command in env variable
780 CONFIG_CMD_SAVES * save S record dump
781 CONFIG_CMD_SCSI * SCSI Support
782 CONFIG_CMD_SDRAM * print SDRAM configuration information
783 (requires CONFIG_CMD_I2C)
784 CONFIG_CMD_SETGETDCR Support for DCR Register access
786 CONFIG_CMD_SHA1SUM print sha1 memory digest
787 (requires CONFIG_CMD_MEMORY)
788 CONFIG_CMD_SOURCE "source" command Support
789 CONFIG_CMD_SPI * SPI serial bus support
790 CONFIG_CMD_TFTPSRV * TFTP transfer in server mode
791 CONFIG_CMD_TFTPPUT * TFTP put command (upload)
792 CONFIG_CMD_TIME * run command and report execution time
793 CONFIG_CMD_USB * USB support
794 CONFIG_CMD_CDP * Cisco Discover Protocol support
795 CONFIG_CMD_FSL * Microblaze FSL support
798 EXAMPLE: If you want all functions except of network
799 support you can write:
801 #include "config_cmd_all.h"
802 #undef CONFIG_CMD_NET
805 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
807 Note: Don't enable the "icache" and "dcache" commands
808 (configuration option CONFIG_CMD_CACHE) unless you know
809 what you (and your U-Boot users) are doing. Data
810 cache cannot be enabled on systems like the 8xx or
811 8260 (where accesses to the IMMR region must be
812 uncached), and it cannot be disabled on all other
813 systems where we (mis-) use the data cache to hold an
814 initial stack and some data.
817 XXX - this list needs to get updated!
821 If this variable is defined, U-Boot will use a device tree
822 to configure its devices, instead of relying on statically
823 compiled #defines in the board file. This option is
824 experimental and only available on a few boards. The device
825 tree is available in the global data as gd->fdt_blob.
827 U-Boot needs to get its device tree from somewhere. At present
828 the only way is to embed it in the image with CONFIG_OF_EMBED.
831 If this variable is defined, U-Boot will embed a device tree
832 binary in its image. This device tree file should be in the
833 board directory and called <soc>-<board>.dts. The binary file
834 is then picked up in board_init_f() and made available through
835 the global data structure as gd->blob.
839 If this variable is defined, it enables watchdog
840 support for the SoC. There must be support in the SoC
841 specific code for a watchdog. For the 8xx and 8260
842 CPUs, the SIU Watchdog feature is enabled in the SYPCR
843 register. When supported for a specific SoC is
844 available, then no further board specific code should
848 When using a watchdog circuitry external to the used
849 SoC, then define this variable and provide board
850 specific code for the "hw_watchdog_reset" function.
853 CONFIG_VERSION_VARIABLE
854 If this variable is defined, an environment variable
855 named "ver" is created by U-Boot showing the U-Boot
856 version as printed by the "version" command.
857 This variable is readonly.
861 When CONFIG_CMD_DATE is selected, the type of the RTC
862 has to be selected, too. Define exactly one of the
865 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
866 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
867 CONFIG_RTC_MC13783 - use MC13783 RTC
868 CONFIG_RTC_MC146818 - use MC146818 RTC
869 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
870 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
871 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
872 CONFIG_RTC_DS164x - use Dallas DS164x RTC
873 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
874 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
875 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
876 CONFIG_SYS_RV3029_TCR - enable trickle charger on
879 Note that if the RTC uses I2C, then the I2C interface
880 must also be configured. See I2C Support, below.
883 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
884 CONFIG_PCA953X_INFO - enable pca953x info command
886 The CONFIG_SYS_I2C_PCA953X_WIDTH option specifies a list of
887 chip-ngpio pairs that tell the PCA953X driver the number of
888 pins supported by a particular chip.
890 Note that if the GPIO device uses I2C, then the I2C interface
891 must also be configured. See I2C Support, below.
895 When CONFIG_TIMESTAMP is selected, the timestamp
896 (date and time) of an image is printed by image
897 commands like bootm or iminfo. This option is
898 automatically enabled when you select CONFIG_CMD_DATE .
901 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
902 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
904 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
905 CONFIG_CMD_SCSI) you must configure support for at
906 least one partition type as well.
909 CONFIG_IDE_RESET_ROUTINE - this is defined in several
910 board configurations files but used nowhere!
912 CONFIG_IDE_RESET - is this is defined, IDE Reset will
913 be performed by calling the function
914 ide_set_reset(int reset)
915 which has to be defined in a board specific file
920 Set this to enable ATAPI support.
925 Set this to enable support for disks larger than 137GB
926 Also look at CONFIG_SYS_64BIT_LBA.
927 Whithout these , LBA48 support uses 32bit variables and will 'only'
928 support disks up to 2.1TB.
930 CONFIG_SYS_64BIT_LBA:
931 When enabled, makes the IDE subsystem use 64bit sector addresses.
935 At the moment only there is only support for the
936 SYM53C8XX SCSI controller; define
937 CONFIG_SCSI_SYM53C8XX to enable it.
939 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
940 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
941 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
942 maximum numbers of LUNs, SCSI ID's and target
944 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
946 - NETWORK Support (PCI):
948 Support for Intel 8254x gigabit chips.
950 CONFIG_E1000_FALLBACK_MAC
951 default MAC for empty EEPROM after production.
954 Support for Intel 82557/82559/82559ER chips.
955 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
956 write routine for first time initialisation.
959 Support for Digital 2114x chips.
960 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
961 modem chip initialisation (KS8761/QS6611).
964 Support for National dp83815 chips.
967 Support for National dp8382[01] gigabit chips.
969 - NETWORK Support (other):
971 CONFIG_DRIVER_AT91EMAC
972 Support for AT91RM9200 EMAC.
975 Define this to use reduced MII inteface
977 CONFIG_DRIVER_AT91EMAC_QUIET
978 If this defined, the driver is quiet.
979 The driver doen't show link status messages.
981 CONFIG_DRIVER_LAN91C96
982 Support for SMSC's LAN91C96 chips.
985 Define this to hold the physical address
986 of the LAN91C96's I/O space
988 CONFIG_LAN91C96_USE_32_BIT
989 Define this to enable 32 bit addressing
991 CONFIG_DRIVER_SMC91111
992 Support for SMSC's LAN91C111 chip
995 Define this to hold the physical address
996 of the device (I/O space)
998 CONFIG_SMC_USE_32_BIT
999 Define this if data bus is 32 bits
1001 CONFIG_SMC_USE_IOFUNCS
1002 Define this to use i/o functions instead of macros
1003 (some hardware wont work with macros)
1006 Support for Faraday's FTGMAC100 Gigabit SoC Ethernet
1008 CONFIG_FTGMAC100_EGIGA
1009 Define this to use GE link update with gigabit PHY.
1010 Define this if FTGMAC100 is connected to gigabit PHY.
1011 If your system has 10/100 PHY only, it might not occur
1012 wrong behavior. Because PHY usually return timeout or
1013 useless data when polling gigabit status and gigabit
1014 control registers. This behavior won't affect the
1015 correctnessof 10/100 link speed update.
1018 Support for SMSC's LAN911x and LAN921x chips
1021 Define this to hold the physical address
1022 of the device (I/O space)
1024 CONFIG_SMC911X_32_BIT
1025 Define this if data bus is 32 bits
1027 CONFIG_SMC911X_16_BIT
1028 Define this if data bus is 16 bits. If your processor
1029 automatically converts one 32 bit word to two 16 bit
1030 words you may also try CONFIG_SMC911X_32_BIT.
1033 Support for Renesas on-chip Ethernet controller
1035 CONFIG_SH_ETHER_USE_PORT
1036 Define the number of ports to be used
1038 CONFIG_SH_ETHER_PHY_ADDR
1039 Define the ETH PHY's address
1041 CONFIG_SH_ETHER_CACHE_WRITEBACK
1042 If this option is set, the driver enables cache flush.
1045 At the moment only the UHCI host controller is
1046 supported (PIP405, MIP405, MPC5200); define
1047 CONFIG_USB_UHCI to enable it.
1048 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
1049 and define CONFIG_USB_STORAGE to enable the USB
1052 Supported are USB Keyboards and USB Floppy drives
1054 MPC5200 USB requires additional defines:
1056 for 528 MHz Clock: 0x0001bbbb
1060 for differential drivers: 0x00001000
1061 for single ended drivers: 0x00005000
1062 for differential drivers on PSC3: 0x00000100
1063 for single ended drivers on PSC3: 0x00004100
1064 CONFIG_SYS_USB_EVENT_POLL
1065 May be defined to allow interrupt polling
1066 instead of using asynchronous interrupts
1069 Define the below if you wish to use the USB console.
1070 Once firmware is rebuilt from a serial console issue the
1071 command "setenv stdin usbtty; setenv stdout usbtty" and
1072 attach your USB cable. The Unix command "dmesg" should print
1073 it has found a new device. The environment variable usbtty
1074 can be set to gserial or cdc_acm to enable your device to
1075 appear to a USB host as a Linux gserial device or a
1076 Common Device Class Abstract Control Model serial device.
1077 If you select usbtty = gserial you should be able to enumerate
1079 # modprobe usbserial vendor=0xVendorID product=0xProductID
1080 else if using cdc_acm, simply setting the environment
1081 variable usbtty to be cdc_acm should suffice. The following
1082 might be defined in YourBoardName.h
1085 Define this to build a UDC device
1088 Define this to have a tty type of device available to
1089 talk to the UDC device
1091 CONFIG_SYS_CONSOLE_IS_IN_ENV
1092 Define this if you want stdin, stdout &/or stderr to
1096 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
1097 Derive USB clock from external clock "blah"
1098 - CONFIG_SYS_USB_EXTC_CLK 0x02
1100 CONFIG_SYS_USB_BRG_CLK 0xBLAH
1101 Derive USB clock from brgclk
1102 - CONFIG_SYS_USB_BRG_CLK 0x04
1104 If you have a USB-IF assigned VendorID then you may wish to
1105 define your own vendor specific values either in BoardName.h
1106 or directly in usbd_vendor_info.h. If you don't define
1107 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
1108 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
1109 should pretend to be a Linux device to it's target host.
1111 CONFIG_USBD_MANUFACTURER
1112 Define this string as the name of your company for
1113 - CONFIG_USBD_MANUFACTURER "my company"
1115 CONFIG_USBD_PRODUCT_NAME
1116 Define this string as the name of your product
1117 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
1119 CONFIG_USBD_VENDORID
1120 Define this as your assigned Vendor ID from the USB
1121 Implementors Forum. This *must* be a genuine Vendor ID
1122 to avoid polluting the USB namespace.
1123 - CONFIG_USBD_VENDORID 0xFFFF
1125 CONFIG_USBD_PRODUCTID
1126 Define this as the unique Product ID
1128 - CONFIG_USBD_PRODUCTID 0xFFFF
1132 The MMC controller on the Intel PXA is supported. To
1133 enable this define CONFIG_MMC. The MMC can be
1134 accessed from the boot prompt by mapping the device
1135 to physical memory similar to flash. Command line is
1136 enabled with CONFIG_CMD_MMC. The MMC driver also works with
1137 the FAT fs. This is enabled with CONFIG_CMD_FAT.
1140 Support for Renesas on-chip MMCIF controller
1142 CONFIG_SH_MMCIF_ADDR
1143 Define the base address of MMCIF registers
1146 Define the clock frequency for MMCIF
1148 - Journaling Flash filesystem support:
1149 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
1150 CONFIG_JFFS2_NAND_DEV
1151 Define these for a default partition on a NAND device
1153 CONFIG_SYS_JFFS2_FIRST_SECTOR,
1154 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
1155 Define these for a default partition on a NOR device
1157 CONFIG_SYS_JFFS_CUSTOM_PART
1158 Define this to create an own partition. You have to provide a
1159 function struct part_info* jffs2_part_info(int part_num)
1161 If you define only one JFFS2 partition you may also want to
1162 #define CONFIG_SYS_JFFS_SINGLE_PART 1
1163 to disable the command chpart. This is the default when you
1164 have not defined a custom partition
1169 Define this to enable standard (PC-Style) keyboard
1173 Standard PC keyboard driver with US (is default) and
1174 GERMAN key layout (switch via environment 'keymap=de') support.
1175 Export function i8042_kbd_init, i8042_tstc and i8042_getc
1176 for cfb_console. Supports cursor blinking.
1181 Define this to enable video support (for output to
1184 CONFIG_VIDEO_CT69000
1186 Enable Chips & Technologies 69000 Video chip
1188 CONFIG_VIDEO_SMI_LYNXEM
1189 Enable Silicon Motion SMI 712/710/810 Video chip. The
1190 video output is selected via environment 'videoout'
1191 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
1194 For the CT69000 and SMI_LYNXEM drivers, videomode is
1195 selected via environment 'videomode'. Two different ways
1197 - "videomode=num" 'num' is a standard LiLo mode numbers.
1198 Following standard modes are supported (* is default):
1200 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1201 -------------+---------------------------------------------
1202 8 bits | 0x301* 0x303 0x305 0x161 0x307
1203 15 bits | 0x310 0x313 0x316 0x162 0x319
1204 16 bits | 0x311 0x314 0x317 0x163 0x31A
1205 24 bits | 0x312 0x315 0x318 ? 0x31B
1206 -------------+---------------------------------------------
1207 (i.e. setenv videomode 317; saveenv; reset;)
1209 - "videomode=bootargs" all the video parameters are parsed
1210 from the bootargs. (See drivers/video/videomodes.c)
1213 CONFIG_VIDEO_SED13806
1214 Enable Epson SED13806 driver. This driver supports 8bpp
1215 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1216 or CONFIG_VIDEO_SED13806_16BPP
1219 Enable the Freescale DIU video driver. Reference boards for
1220 SOCs that have a DIU should define this macro to enable DIU
1221 support, and should also define these other macros:
1227 CONFIG_VIDEO_SW_CURSOR
1228 CONFIG_VGA_AS_SINGLE_DEVICE
1230 CONFIG_VIDEO_BMP_LOGO
1232 The DIU driver will look for the 'video-mode' environment
1233 variable, and if defined, enable the DIU as a console during
1234 boot. See the documentation file README.video for a
1235 description of this variable.
1240 Define this to enable a custom keyboard support.
1241 This simply calls drv_keyboard_init() which must be
1242 defined in your board-specific files.
1243 The only board using this so far is RBC823.
1245 - LCD Support: CONFIG_LCD
1247 Define this to enable LCD support (for output to LCD
1248 display); also select one of the supported displays
1249 by defining one of these:
1253 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1255 CONFIG_NEC_NL6448AC33:
1257 NEC NL6448AC33-18. Active, color, single scan.
1259 CONFIG_NEC_NL6448BC20
1261 NEC NL6448BC20-08. 6.5", 640x480.
1262 Active, color, single scan.
1264 CONFIG_NEC_NL6448BC33_54
1266 NEC NL6448BC33-54. 10.4", 640x480.
1267 Active, color, single scan.
1271 Sharp 320x240. Active, color, single scan.
1272 It isn't 16x9, and I am not sure what it is.
1274 CONFIG_SHARP_LQ64D341
1276 Sharp LQ64D341 display, 640x480.
1277 Active, color, single scan.
1281 HLD1045 display, 640x480.
1282 Active, color, single scan.
1286 Optrex CBL50840-2 NF-FW 99 22 M5
1288 Hitachi LMG6912RPFC-00T
1292 320x240. Black & white.
1294 Normally display is black on white background; define
1295 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1297 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1299 If this option is set, the environment is checked for
1300 a variable "splashimage". If found, the usual display
1301 of logo, copyright and system information on the LCD
1302 is suppressed and the BMP image at the address
1303 specified in "splashimage" is loaded instead. The
1304 console is redirected to the "nulldev", too. This
1305 allows for a "silent" boot where a splash screen is
1306 loaded very quickly after power-on.
1308 CONFIG_SPLASH_SCREEN_ALIGN
1310 If this option is set the splash image can be freely positioned
1311 on the screen. Environment variable "splashpos" specifies the
1312 position as "x,y". If a positive number is given it is used as
1313 number of pixel from left/top. If a negative number is given it
1314 is used as number of pixel from right/bottom. You can also
1315 specify 'm' for centering the image.
1318 setenv splashpos m,m
1319 => image at center of screen
1321 setenv splashpos 30,20
1322 => image at x = 30 and y = 20
1324 setenv splashpos -10,m
1325 => vertically centered image
1326 at x = dspWidth - bmpWidth - 9
1328 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1330 If this option is set, additionally to standard BMP
1331 images, gzipped BMP images can be displayed via the
1332 splashscreen support or the bmp command.
1334 - Run length encoded BMP image (RLE8) support: CONFIG_VIDEO_BMP_RLE8
1336 If this option is set, 8-bit RLE compressed BMP images
1337 can be displayed via the splashscreen support or the
1340 - Compression support:
1343 If this option is set, support for bzip2 compressed
1344 images is included. If not, only uncompressed and gzip
1345 compressed images are supported.
1347 NOTE: the bzip2 algorithm requires a lot of RAM, so
1348 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1353 If this option is set, support for lzma compressed
1356 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1357 requires an amount of dynamic memory that is given by the
1360 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1362 Where lc and lp stand for, respectively, Literal context bits
1363 and Literal pos bits.
1365 This value is upper-bounded by 14MB in the worst case. Anyway,
1366 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1367 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1368 a very small buffer.
1370 Use the lzmainfo tool to determinate the lc and lp values and
1371 then calculate the amount of needed dynamic memory (ensuring
1372 the appropriate CONFIG_SYS_MALLOC_LEN value).
1377 The address of PHY on MII bus.
1379 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1381 The clock frequency of the MII bus
1385 If this option is set, support for speed/duplex
1386 detection of gigabit PHY is included.
1388 CONFIG_PHY_RESET_DELAY
1390 Some PHY like Intel LXT971A need extra delay after
1391 reset before any MII register access is possible.
1392 For such PHY, set this option to the usec delay
1393 required. (minimum 300usec for LXT971A)
1395 CONFIG_PHY_CMD_DELAY (ppc4xx)
1397 Some PHY like Intel LXT971A need extra delay after
1398 command issued before MII status register can be read
1408 Define a default value for Ethernet address to use
1409 for the respective Ethernet interface, in case this
1410 is not determined automatically.
1415 Define a default value for the IP address to use for
1416 the default Ethernet interface, in case this is not
1417 determined through e.g. bootp.
1419 - Server IP address:
1422 Defines a default value for the IP address of a TFTP
1423 server to contact when using the "tftboot" command.
1425 CONFIG_KEEP_SERVERADDR
1427 Keeps the server's MAC address, in the env 'serveraddr'
1428 for passing to bootargs (like Linux's netconsole option)
1430 - Multicast TFTP Mode:
1433 Defines whether you want to support multicast TFTP as per
1434 rfc-2090; for example to work with atftp. Lets lots of targets
1435 tftp down the same boot image concurrently. Note: the Ethernet
1436 driver in use must provide a function: mcast() to join/leave a
1439 - BOOTP Recovery Mode:
1440 CONFIG_BOOTP_RANDOM_DELAY
1442 If you have many targets in a network that try to
1443 boot using BOOTP, you may want to avoid that all
1444 systems send out BOOTP requests at precisely the same
1445 moment (which would happen for instance at recovery
1446 from a power failure, when all systems will try to
1447 boot, thus flooding the BOOTP server. Defining
1448 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1449 inserted before sending out BOOTP requests. The
1450 following delays are inserted then:
1452 1st BOOTP request: delay 0 ... 1 sec
1453 2nd BOOTP request: delay 0 ... 2 sec
1454 3rd BOOTP request: delay 0 ... 4 sec
1456 BOOTP requests: delay 0 ... 8 sec
1458 - DHCP Advanced Options:
1459 You can fine tune the DHCP functionality by defining
1460 CONFIG_BOOTP_* symbols:
1462 CONFIG_BOOTP_SUBNETMASK
1463 CONFIG_BOOTP_GATEWAY
1464 CONFIG_BOOTP_HOSTNAME
1465 CONFIG_BOOTP_NISDOMAIN
1466 CONFIG_BOOTP_BOOTPATH
1467 CONFIG_BOOTP_BOOTFILESIZE
1470 CONFIG_BOOTP_SEND_HOSTNAME
1471 CONFIG_BOOTP_NTPSERVER
1472 CONFIG_BOOTP_TIMEOFFSET
1473 CONFIG_BOOTP_VENDOREX
1475 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1476 environment variable, not the BOOTP server.
1478 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1479 serverip from a DHCP server, it is possible that more
1480 than one DNS serverip is offered to the client.
1481 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1482 serverip will be stored in the additional environment
1483 variable "dnsip2". The first DNS serverip is always
1484 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1487 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1488 to do a dynamic update of a DNS server. To do this, they
1489 need the hostname of the DHCP requester.
1490 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1491 of the "hostname" environment variable is passed as
1492 option 12 to the DHCP server.
1494 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1496 A 32bit value in microseconds for a delay between
1497 receiving a "DHCP Offer" and sending the "DHCP Request".
1498 This fixes a problem with certain DHCP servers that don't
1499 respond 100% of the time to a "DHCP request". E.g. On an
1500 AT91RM9200 processor running at 180MHz, this delay needed
1501 to be *at least* 15,000 usec before a Windows Server 2003
1502 DHCP server would reply 100% of the time. I recommend at
1503 least 50,000 usec to be safe. The alternative is to hope
1504 that one of the retries will be successful but note that
1505 the DHCP timeout and retry process takes a longer than
1509 CONFIG_CDP_DEVICE_ID
1511 The device id used in CDP trigger frames.
1513 CONFIG_CDP_DEVICE_ID_PREFIX
1515 A two character string which is prefixed to the MAC address
1520 A printf format string which contains the ascii name of
1521 the port. Normally is set to "eth%d" which sets
1522 eth0 for the first Ethernet, eth1 for the second etc.
1524 CONFIG_CDP_CAPABILITIES
1526 A 32bit integer which indicates the device capabilities;
1527 0x00000010 for a normal host which does not forwards.
1531 An ascii string containing the version of the software.
1535 An ascii string containing the name of the platform.
1539 A 32bit integer sent on the trigger.
1541 CONFIG_CDP_POWER_CONSUMPTION
1543 A 16bit integer containing the power consumption of the
1544 device in .1 of milliwatts.
1546 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1548 A byte containing the id of the VLAN.
1550 - Status LED: CONFIG_STATUS_LED
1552 Several configurations allow to display the current
1553 status using a LED. For instance, the LED will blink
1554 fast while running U-Boot code, stop blinking as
1555 soon as a reply to a BOOTP request was received, and
1556 start blinking slow once the Linux kernel is running
1557 (supported by a status LED driver in the Linux
1558 kernel). Defining CONFIG_STATUS_LED enables this
1561 - CAN Support: CONFIG_CAN_DRIVER
1563 Defining CONFIG_CAN_DRIVER enables CAN driver support
1564 on those systems that support this (optional)
1565 feature, like the TQM8xxL modules.
1567 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1569 These enable I2C serial bus commands. Defining either of
1570 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1571 include the appropriate I2C driver for the selected CPU.
1573 This will allow you to use i2c commands at the u-boot
1574 command line (as long as you set CONFIG_CMD_I2C in
1575 CONFIG_COMMANDS) and communicate with i2c based realtime
1576 clock chips. See common/cmd_i2c.c for a description of the
1577 command line interface.
1579 CONFIG_HARD_I2C selects a hardware I2C controller.
1581 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1582 bit-banging) driver instead of CPM or similar hardware
1585 There are several other quantities that must also be
1586 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1588 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1589 to be the frequency (in Hz) at which you wish your i2c bus
1590 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1591 the CPU's i2c node address).
1593 Now, the u-boot i2c code for the mpc8xx
1594 (arch/powerpc/cpu/mpc8xx/i2c.c) sets the CPU up as a master node
1595 and so its address should therefore be cleared to 0 (See,
1596 eg, MPC823e User's Manual p.16-473). So, set
1597 CONFIG_SYS_I2C_SLAVE to 0.
1599 CONFIG_SYS_I2C_INIT_MPC5XXX
1601 When a board is reset during an i2c bus transfer
1602 chips might think that the current transfer is still
1603 in progress. Reset the slave devices by sending start
1604 commands until the slave device responds.
1606 That's all that's required for CONFIG_HARD_I2C.
1608 If you use the software i2c interface (CONFIG_SOFT_I2C)
1609 then the following macros need to be defined (examples are
1610 from include/configs/lwmon.h):
1614 (Optional). Any commands necessary to enable the I2C
1615 controller or configure ports.
1617 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1621 (Only for MPC8260 CPU). The I/O port to use (the code
1622 assumes both bits are on the same port). Valid values
1623 are 0..3 for ports A..D.
1627 The code necessary to make the I2C data line active
1628 (driven). If the data line is open collector, this
1631 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1635 The code necessary to make the I2C data line tri-stated
1636 (inactive). If the data line is open collector, this
1639 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1643 Code that returns TRUE if the I2C data line is high,
1646 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1650 If <bit> is TRUE, sets the I2C data line high. If it
1651 is FALSE, it clears it (low).
1653 eg: #define I2C_SDA(bit) \
1654 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1655 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1659 If <bit> is TRUE, sets the I2C clock line high. If it
1660 is FALSE, it clears it (low).
1662 eg: #define I2C_SCL(bit) \
1663 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1664 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1668 This delay is invoked four times per clock cycle so this
1669 controls the rate of data transfer. The data rate thus
1670 is 1 / (I2C_DELAY * 4). Often defined to be something
1673 #define I2C_DELAY udelay(2)
1675 CONFIG_SOFT_I2C_GPIO_SCL / CONFIG_SOFT_I2C_GPIO_SDA
1677 If your arch supports the generic GPIO framework (asm/gpio.h),
1678 then you may alternatively define the two GPIOs that are to be
1679 used as SCL / SDA. Any of the previous I2C_xxx macros will
1680 have GPIO-based defaults assigned to them as appropriate.
1682 You should define these to the GPIO value as given directly to
1683 the generic GPIO functions.
1685 CONFIG_SYS_I2C_INIT_BOARD
1687 When a board is reset during an i2c bus transfer
1688 chips might think that the current transfer is still
1689 in progress. On some boards it is possible to access
1690 the i2c SCLK line directly, either by using the
1691 processor pin as a GPIO or by having a second pin
1692 connected to the bus. If this option is defined a
1693 custom i2c_init_board() routine in boards/xxx/board.c
1694 is run early in the boot sequence.
1696 CONFIG_SYS_I2C_BOARD_LATE_INIT
1698 An alternative to CONFIG_SYS_I2C_INIT_BOARD. If this option is
1699 defined a custom i2c_board_late_init() routine in
1700 boards/xxx/board.c is run AFTER the operations in i2c_init()
1701 is completed. This callpoint can be used to unreset i2c bus
1702 using CPU i2c controller register accesses for CPUs whose i2c
1703 controller provide such a method. It is called at the end of
1704 i2c_init() to allow i2c_init operations to setup the i2c bus
1705 controller on the CPU (e.g. setting bus speed & slave address).
1707 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1709 This option enables configuration of bi_iic_fast[] flags
1710 in u-boot bd_info structure based on u-boot environment
1711 variable "i2cfast". (see also i2cfast)
1713 CONFIG_I2C_MULTI_BUS
1715 This option allows the use of multiple I2C buses, each of which
1716 must have a controller. At any point in time, only one bus is
1717 active. To switch to a different bus, use the 'i2c dev' command.
1718 Note that bus numbering is zero-based.
1720 CONFIG_SYS_I2C_NOPROBES
1722 This option specifies a list of I2C devices that will be skipped
1723 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1724 is set, specify a list of bus-device pairs. Otherwise, specify
1725 a 1D array of device addresses
1728 #undef CONFIG_I2C_MULTI_BUS
1729 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1731 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1733 #define CONFIG_I2C_MULTI_BUS
1734 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1736 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1738 CONFIG_SYS_SPD_BUS_NUM
1740 If defined, then this indicates the I2C bus number for DDR SPD.
1741 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1743 CONFIG_SYS_RTC_BUS_NUM
1745 If defined, then this indicates the I2C bus number for the RTC.
1746 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1748 CONFIG_SYS_DTT_BUS_NUM
1750 If defined, then this indicates the I2C bus number for the DTT.
1751 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1753 CONFIG_SYS_I2C_DTT_ADDR:
1755 If defined, specifies the I2C address of the DTT device.
1756 If not defined, then U-Boot uses predefined value for
1757 specified DTT device.
1761 Define this option if you want to use Freescale's I2C driver in
1762 drivers/i2c/fsl_i2c.c.
1766 Define this option if you have I2C devices reached over 1 .. n
1767 I2C Muxes like the pca9544a. This option addes a new I2C
1768 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1769 new I2C Bus to the existing I2C Busses. If you select the
1770 new Bus with "i2c dev", u-bbot sends first the commandos for
1771 the muxes to activate this new "bus".
1773 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1777 Adding a new I2C Bus reached over 2 pca9544a muxes
1778 The First mux with address 70 and channel 6
1779 The Second mux with address 71 and channel 4
1781 => i2c bus pca9544a:70:6:pca9544a:71:4
1783 Use the "i2c bus" command without parameter, to get a list
1784 of I2C Busses with muxes:
1787 Busses reached over muxes:
1789 reached over Mux(es):
1792 reached over Mux(es):
1797 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1798 u-boot first sends the command to the mux@70 to enable
1799 channel 6, and then the command to the mux@71 to enable
1802 After that, you can use the "normal" i2c commands as
1803 usual to communicate with your I2C devices behind
1806 This option is actually implemented for the bitbanging
1807 algorithm in common/soft_i2c.c and for the Hardware I2C
1808 Bus on the MPC8260. But it should be not so difficult
1809 to add this option to other architectures.
1811 CONFIG_SOFT_I2C_READ_REPEATED_START
1813 defining this will force the i2c_read() function in
1814 the soft_i2c driver to perform an I2C repeated start
1815 between writing the address pointer and reading the
1816 data. If this define is omitted the default behaviour
1817 of doing a stop-start sequence will be used. Most I2C
1818 devices can use either method, but some require one or
1821 - SPI Support: CONFIG_SPI
1823 Enables SPI driver (so far only tested with
1824 SPI EEPROM, also an instance works with Crystal A/D and
1825 D/As on the SACSng board)
1829 Enables the driver for SPI controller on SuperH. Currently
1830 only SH7757 is supported.
1834 Enables extended (16-bit) SPI EEPROM addressing.
1835 (symmetrical to CONFIG_I2C_X)
1839 Enables a software (bit-bang) SPI driver rather than
1840 using hardware support. This is a general purpose
1841 driver that only requires three general I/O port pins
1842 (two outputs, one input) to function. If this is
1843 defined, the board configuration must define several
1844 SPI configuration items (port pins to use, etc). For
1845 an example, see include/configs/sacsng.h.
1849 Enables a hardware SPI driver for general-purpose reads
1850 and writes. As with CONFIG_SOFT_SPI, the board configuration
1851 must define a list of chip-select function pointers.
1852 Currently supported on some MPC8xxx processors. For an
1853 example, see include/configs/mpc8349emds.h.
1857 Enables the driver for the SPI controllers on i.MX and MXC
1858 SoCs. Currently only i.MX31 is supported.
1860 - FPGA Support: CONFIG_FPGA
1862 Enables FPGA subsystem.
1864 CONFIG_FPGA_<vendor>
1866 Enables support for specific chip vendors.
1869 CONFIG_FPGA_<family>
1871 Enables support for FPGA family.
1872 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1876 Specify the number of FPGA devices to support.
1878 CONFIG_SYS_FPGA_PROG_FEEDBACK
1880 Enable printing of hash marks during FPGA configuration.
1882 CONFIG_SYS_FPGA_CHECK_BUSY
1884 Enable checks on FPGA configuration interface busy
1885 status by the configuration function. This option
1886 will require a board or device specific function to
1891 If defined, a function that provides delays in the FPGA
1892 configuration driver.
1894 CONFIG_SYS_FPGA_CHECK_CTRLC
1895 Allow Control-C to interrupt FPGA configuration
1897 CONFIG_SYS_FPGA_CHECK_ERROR
1899 Check for configuration errors during FPGA bitfile
1900 loading. For example, abort during Virtex II
1901 configuration if the INIT_B line goes low (which
1902 indicated a CRC error).
1904 CONFIG_SYS_FPGA_WAIT_INIT
1906 Maximum time to wait for the INIT_B line to deassert
1907 after PROB_B has been deasserted during a Virtex II
1908 FPGA configuration sequence. The default time is 500
1911 CONFIG_SYS_FPGA_WAIT_BUSY
1913 Maximum time to wait for BUSY to deassert during
1914 Virtex II FPGA configuration. The default is 5 ms.
1916 CONFIG_SYS_FPGA_WAIT_CONFIG
1918 Time to wait after FPGA configuration. The default is
1921 - Configuration Management:
1924 If defined, this string will be added to the U-Boot
1925 version information (U_BOOT_VERSION)
1927 - Vendor Parameter Protection:
1929 U-Boot considers the values of the environment
1930 variables "serial#" (Board Serial Number) and
1931 "ethaddr" (Ethernet Address) to be parameters that
1932 are set once by the board vendor / manufacturer, and
1933 protects these variables from casual modification by
1934 the user. Once set, these variables are read-only,
1935 and write or delete attempts are rejected. You can
1936 change this behaviour:
1938 If CONFIG_ENV_OVERWRITE is #defined in your config
1939 file, the write protection for vendor parameters is
1940 completely disabled. Anybody can change or delete
1943 Alternatively, if you #define _both_ CONFIG_ETHADDR
1944 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1945 Ethernet address is installed in the environment,
1946 which can be changed exactly ONCE by the user. [The
1947 serial# is unaffected by this, i. e. it remains
1953 Define this variable to enable the reservation of
1954 "protected RAM", i. e. RAM which is not overwritten
1955 by U-Boot. Define CONFIG_PRAM to hold the number of
1956 kB you want to reserve for pRAM. You can overwrite
1957 this default value by defining an environment
1958 variable "pram" to the number of kB you want to
1959 reserve. Note that the board info structure will
1960 still show the full amount of RAM. If pRAM is
1961 reserved, a new environment variable "mem" will
1962 automatically be defined to hold the amount of
1963 remaining RAM in a form that can be passed as boot
1964 argument to Linux, for instance like that:
1966 setenv bootargs ... mem=\${mem}
1969 This way you can tell Linux not to use this memory,
1970 either, which results in a memory region that will
1971 not be affected by reboots.
1973 *WARNING* If your board configuration uses automatic
1974 detection of the RAM size, you must make sure that
1975 this memory test is non-destructive. So far, the
1976 following board configurations are known to be
1979 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1980 HERMES, IP860, RPXlite, LWMON, LANTEC,
1986 Define this variable to stop the system in case of a
1987 fatal error, so that you have to reset it manually.
1988 This is probably NOT a good idea for an embedded
1989 system where you want the system to reboot
1990 automatically as fast as possible, but it may be
1991 useful during development since you can try to debug
1992 the conditions that lead to the situation.
1994 CONFIG_NET_RETRY_COUNT
1996 This variable defines the number of retries for
1997 network operations like ARP, RARP, TFTP, or BOOTP
1998 before giving up the operation. If not defined, a
1999 default value of 5 is used.
2003 Timeout waiting for an ARP reply in milliseconds.
2005 - Command Interpreter:
2006 CONFIG_AUTO_COMPLETE
2008 Enable auto completion of commands using TAB.
2010 Note that this feature has NOT been implemented yet
2011 for the "hush" shell.
2014 CONFIG_SYS_HUSH_PARSER
2016 Define this variable to enable the "hush" shell (from
2017 Busybox) as command line interpreter, thus enabling
2018 powerful command line syntax like
2019 if...then...else...fi conditionals or `&&' and '||'
2020 constructs ("shell scripts").
2022 If undefined, you get the old, much simpler behaviour
2023 with a somewhat smaller memory footprint.
2026 CONFIG_SYS_PROMPT_HUSH_PS2
2028 This defines the secondary prompt string, which is
2029 printed when the command interpreter needs more input
2030 to complete a command. Usually "> ".
2034 In the current implementation, the local variables
2035 space and global environment variables space are
2036 separated. Local variables are those you define by
2037 simply typing `name=value'. To access a local
2038 variable later on, you have write `$name' or
2039 `${name}'; to execute the contents of a variable
2040 directly type `$name' at the command prompt.
2042 Global environment variables are those you use
2043 setenv/printenv to work with. To run a command stored
2044 in such a variable, you need to use the run command,
2045 and you must not use the '$' sign to access them.
2047 To store commands and special characters in a
2048 variable, please use double quotation marks
2049 surrounding the whole text of the variable, instead
2050 of the backslashes before semicolons and special
2053 - Commandline Editing and History:
2054 CONFIG_CMDLINE_EDITING
2056 Enable editing and History functions for interactive
2057 commandline input operations
2059 - Default Environment:
2060 CONFIG_EXTRA_ENV_SETTINGS
2062 Define this to contain any number of null terminated
2063 strings (variable = value pairs) that will be part of
2064 the default environment compiled into the boot image.
2066 For example, place something like this in your
2067 board's config file:
2069 #define CONFIG_EXTRA_ENV_SETTINGS \
2073 Warning: This method is based on knowledge about the
2074 internal format how the environment is stored by the
2075 U-Boot code. This is NOT an official, exported
2076 interface! Although it is unlikely that this format
2077 will change soon, there is no guarantee either.
2078 You better know what you are doing here.
2080 Note: overly (ab)use of the default environment is
2081 discouraged. Make sure to check other ways to preset
2082 the environment like the "source" command or the
2085 - DataFlash Support:
2086 CONFIG_HAS_DATAFLASH
2088 Defining this option enables DataFlash features and
2089 allows to read/write in Dataflash via the standard
2092 - SystemACE Support:
2095 Adding this option adds support for Xilinx SystemACE
2096 chips attached via some sort of local bus. The address
2097 of the chip must also be defined in the
2098 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
2100 #define CONFIG_SYSTEMACE
2101 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
2103 When SystemACE support is added, the "ace" device type
2104 becomes available to the fat commands, i.e. fatls.
2106 - TFTP Fixed UDP Port:
2109 If this is defined, the environment variable tftpsrcp
2110 is used to supply the TFTP UDP source port value.
2111 If tftpsrcp isn't defined, the normal pseudo-random port
2112 number generator is used.
2114 Also, the environment variable tftpdstp is used to supply
2115 the TFTP UDP destination port value. If tftpdstp isn't
2116 defined, the normal port 69 is used.
2118 The purpose for tftpsrcp is to allow a TFTP server to
2119 blindly start the TFTP transfer using the pre-configured
2120 target IP address and UDP port. This has the effect of
2121 "punching through" the (Windows XP) firewall, allowing
2122 the remainder of the TFTP transfer to proceed normally.
2123 A better solution is to properly configure the firewall,
2124 but sometimes that is not allowed.
2126 - Show boot progress:
2127 CONFIG_SHOW_BOOT_PROGRESS
2129 Defining this option allows to add some board-
2130 specific code (calling a user-provided function
2131 "show_boot_progress(int)") that enables you to show
2132 the system's boot progress on some display (for
2133 example, some LED's) on your board. At the moment,
2134 the following checkpoints are implemented:
2136 Legacy uImage format:
2139 1 common/cmd_bootm.c before attempting to boot an image
2140 -1 common/cmd_bootm.c Image header has bad magic number
2141 2 common/cmd_bootm.c Image header has correct magic number
2142 -2 common/cmd_bootm.c Image header has bad checksum
2143 3 common/cmd_bootm.c Image header has correct checksum
2144 -3 common/cmd_bootm.c Image data has bad checksum
2145 4 common/cmd_bootm.c Image data has correct checksum
2146 -4 common/cmd_bootm.c Image is for unsupported architecture
2147 5 common/cmd_bootm.c Architecture check OK
2148 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
2149 6 common/cmd_bootm.c Image Type check OK
2150 -6 common/cmd_bootm.c gunzip uncompression error
2151 -7 common/cmd_bootm.c Unimplemented compression type
2152 7 common/cmd_bootm.c Uncompression OK
2153 8 common/cmd_bootm.c No uncompress/copy overwrite error
2154 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
2156 9 common/image.c Start initial ramdisk verification
2157 -10 common/image.c Ramdisk header has bad magic number
2158 -11 common/image.c Ramdisk header has bad checksum
2159 10 common/image.c Ramdisk header is OK
2160 -12 common/image.c Ramdisk data has bad checksum
2161 11 common/image.c Ramdisk data has correct checksum
2162 12 common/image.c Ramdisk verification complete, start loading
2163 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
2164 13 common/image.c Start multifile image verification
2165 14 common/image.c No initial ramdisk, no multifile, continue.
2167 15 arch/<arch>/lib/bootm.c All preparation done, transferring control to OS
2169 -30 arch/powerpc/lib/board.c Fatal error, hang the system
2170 -31 post/post.c POST test failed, detected by post_output_backlog()
2171 -32 post/post.c POST test failed, detected by post_run_single()
2173 34 common/cmd_doc.c before loading a Image from a DOC device
2174 -35 common/cmd_doc.c Bad usage of "doc" command
2175 35 common/cmd_doc.c correct usage of "doc" command
2176 -36 common/cmd_doc.c No boot device
2177 36 common/cmd_doc.c correct boot device
2178 -37 common/cmd_doc.c Unknown Chip ID on boot device
2179 37 common/cmd_doc.c correct chip ID found, device available
2180 -38 common/cmd_doc.c Read Error on boot device
2181 38 common/cmd_doc.c reading Image header from DOC device OK
2182 -39 common/cmd_doc.c Image header has bad magic number
2183 39 common/cmd_doc.c Image header has correct magic number
2184 -40 common/cmd_doc.c Error reading Image from DOC device
2185 40 common/cmd_doc.c Image header has correct magic number
2186 41 common/cmd_ide.c before loading a Image from a IDE device
2187 -42 common/cmd_ide.c Bad usage of "ide" command
2188 42 common/cmd_ide.c correct usage of "ide" command
2189 -43 common/cmd_ide.c No boot device
2190 43 common/cmd_ide.c boot device found
2191 -44 common/cmd_ide.c Device not available
2192 44 common/cmd_ide.c Device available
2193 -45 common/cmd_ide.c wrong partition selected
2194 45 common/cmd_ide.c partition selected
2195 -46 common/cmd_ide.c Unknown partition table
2196 46 common/cmd_ide.c valid partition table found
2197 -47 common/cmd_ide.c Invalid partition type
2198 47 common/cmd_ide.c correct partition type
2199 -48 common/cmd_ide.c Error reading Image Header on boot device
2200 48 common/cmd_ide.c reading Image Header from IDE device OK
2201 -49 common/cmd_ide.c Image header has bad magic number
2202 49 common/cmd_ide.c Image header has correct magic number
2203 -50 common/cmd_ide.c Image header has bad checksum
2204 50 common/cmd_ide.c Image header has correct checksum
2205 -51 common/cmd_ide.c Error reading Image from IDE device
2206 51 common/cmd_ide.c reading Image from IDE device OK
2207 52 common/cmd_nand.c before loading a Image from a NAND device
2208 -53 common/cmd_nand.c Bad usage of "nand" command
2209 53 common/cmd_nand.c correct usage of "nand" command
2210 -54 common/cmd_nand.c No boot device
2211 54 common/cmd_nand.c boot device found
2212 -55 common/cmd_nand.c Unknown Chip ID on boot device
2213 55 common/cmd_nand.c correct chip ID found, device available
2214 -56 common/cmd_nand.c Error reading Image Header on boot device
2215 56 common/cmd_nand.c reading Image Header from NAND device OK
2216 -57 common/cmd_nand.c Image header has bad magic number
2217 57 common/cmd_nand.c Image header has correct magic number
2218 -58 common/cmd_nand.c Error reading Image from NAND device
2219 58 common/cmd_nand.c reading Image from NAND device OK
2221 -60 common/env_common.c Environment has a bad CRC, using default
2223 64 net/eth.c starting with Ethernet configuration.
2224 -64 net/eth.c no Ethernet found.
2225 65 net/eth.c Ethernet found.
2227 -80 common/cmd_net.c usage wrong
2228 80 common/cmd_net.c before calling NetLoop()
2229 -81 common/cmd_net.c some error in NetLoop() occurred
2230 81 common/cmd_net.c NetLoop() back without error
2231 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2232 82 common/cmd_net.c trying automatic boot
2233 83 common/cmd_net.c running "source" command
2234 -83 common/cmd_net.c some error in automatic boot or "source" command
2235 84 common/cmd_net.c end without errors
2240 100 common/cmd_bootm.c Kernel FIT Image has correct format
2241 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2242 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2243 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2244 102 common/cmd_bootm.c Kernel unit name specified
2245 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2246 103 common/cmd_bootm.c Found configuration node
2247 104 common/cmd_bootm.c Got kernel subimage node offset
2248 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2249 105 common/cmd_bootm.c Kernel subimage hash verification OK
2250 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2251 106 common/cmd_bootm.c Architecture check OK
2252 -106 common/cmd_bootm.c Kernel subimage has wrong type
2253 107 common/cmd_bootm.c Kernel subimage type OK
2254 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2255 108 common/cmd_bootm.c Got kernel subimage data/size
2256 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2257 -109 common/cmd_bootm.c Can't get kernel subimage type
2258 -110 common/cmd_bootm.c Can't get kernel subimage comp
2259 -111 common/cmd_bootm.c Can't get kernel subimage os
2260 -112 common/cmd_bootm.c Can't get kernel subimage load address
2261 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2263 120 common/image.c Start initial ramdisk verification
2264 -120 common/image.c Ramdisk FIT image has incorrect format
2265 121 common/image.c Ramdisk FIT image has correct format
2266 122 common/image.c No ramdisk subimage unit name, using configuration
2267 -122 common/image.c Can't get configuration for ramdisk subimage
2268 123 common/image.c Ramdisk unit name specified
2269 -124 common/image.c Can't get ramdisk subimage node offset
2270 125 common/image.c Got ramdisk subimage node offset
2271 -125 common/image.c Ramdisk subimage hash verification failed
2272 126 common/image.c Ramdisk subimage hash verification OK
2273 -126 common/image.c Ramdisk subimage for unsupported architecture
2274 127 common/image.c Architecture check OK
2275 -127 common/image.c Can't get ramdisk subimage data/size
2276 128 common/image.c Got ramdisk subimage data/size
2277 129 common/image.c Can't get ramdisk load address
2278 -129 common/image.c Got ramdisk load address
2280 -130 common/cmd_doc.c Incorrect FIT image format
2281 131 common/cmd_doc.c FIT image format OK
2283 -140 common/cmd_ide.c Incorrect FIT image format
2284 141 common/cmd_ide.c FIT image format OK
2286 -150 common/cmd_nand.c Incorrect FIT image format
2287 151 common/cmd_nand.c FIT image format OK
2289 - Standalone program support:
2290 CONFIG_STANDALONE_LOAD_ADDR
2292 This option defines a board specific value for the
2293 address where standalone program gets loaded, thus
2294 overwriting the architecture dependent default
2297 - Frame Buffer Address:
2300 Define CONFIG_FB_ADDR if you want to use specific
2301 address for frame buffer.
2302 Then system will reserve the frame buffer address to
2303 defined address instead of lcd_setmem (this function
2304 grabs the memory for frame buffer by panel's size).
2306 Please see board_init_f function.
2308 - Automatic software updates via TFTP server
2310 CONFIG_UPDATE_TFTP_CNT_MAX
2311 CONFIG_UPDATE_TFTP_MSEC_MAX
2313 These options enable and control the auto-update feature;
2314 for a more detailed description refer to doc/README.update.
2316 - MTD Support (mtdparts command, UBI support)
2319 Adds the MTD device infrastructure from the Linux kernel.
2320 Needed for mtdparts command support.
2322 CONFIG_MTD_PARTITIONS
2324 Adds the MTD partitioning infrastructure from the Linux
2325 kernel. Needed for UBI support.
2329 Enable building of SPL globally.
2331 CONFIG_SPL_TEXT_BASE
2332 TEXT_BASE for linking the SPL binary.
2335 LDSCRIPT for linking the SPL binary.
2337 CONFIG_SPL_LIBCOMMON_SUPPORT
2338 Support for common/libcommon.o in SPL binary
2340 CONFIG_SPL_LIBDISK_SUPPORT
2341 Support for disk/libdisk.o in SPL binary
2343 CONFIG_SPL_I2C_SUPPORT
2344 Support for drivers/i2c/libi2c.o in SPL binary
2346 CONFIG_SPL_GPIO_SUPPORT
2347 Support for drivers/gpio/libgpio.o in SPL binary
2349 CONFIG_SPL_MMC_SUPPORT
2350 Support for drivers/mmc/libmmc.o in SPL binary
2352 CONFIG_SPL_SERIAL_SUPPORT
2353 Support for drivers/serial/libserial.o in SPL binary
2355 CONFIG_SPL_SPI_FLASH_SUPPORT
2356 Support for drivers/mtd/spi/libspi_flash.o in SPL binary
2358 CONFIG_SPL_SPI_SUPPORT
2359 Support for drivers/spi/libspi.o in SPL binary
2361 CONFIG_SPL_FAT_SUPPORT
2362 Support for fs/fat/libfat.o in SPL binary
2364 CONFIG_SPL_LIBGENERIC_SUPPORT
2365 Support for lib/libgeneric.o in SPL binary
2370 [so far only for SMDK2400 boards]
2372 - Modem support enable:
2373 CONFIG_MODEM_SUPPORT
2375 - RTS/CTS Flow control enable:
2378 - Modem debug support:
2379 CONFIG_MODEM_SUPPORT_DEBUG
2381 Enables debugging stuff (char screen[1024], dbg())
2382 for modem support. Useful only with BDI2000.
2384 - Interrupt support (PPC):
2386 There are common interrupt_init() and timer_interrupt()
2387 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2388 for CPU specific initialization. interrupt_init_cpu()
2389 should set decrementer_count to appropriate value. If
2390 CPU resets decrementer automatically after interrupt
2391 (ppc4xx) it should set decrementer_count to zero.
2392 timer_interrupt() calls timer_interrupt_cpu() for CPU
2393 specific handling. If board has watchdog / status_led
2394 / other_activity_monitor it works automatically from
2395 general timer_interrupt().
2399 In the target system modem support is enabled when a
2400 specific key (key combination) is pressed during
2401 power-on. Otherwise U-Boot will boot normally
2402 (autoboot). The key_pressed() function is called from
2403 board_init(). Currently key_pressed() is a dummy
2404 function, returning 1 and thus enabling modem
2407 If there are no modem init strings in the
2408 environment, U-Boot proceed to autoboot; the
2409 previous output (banner, info printfs) will be
2412 See also: doc/README.Modem
2415 Configuration Settings:
2416 -----------------------
2418 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2419 undefine this when you're short of memory.
2421 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2422 width of the commands listed in the 'help' command output.
2424 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2425 prompt for user input.
2427 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2429 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2431 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2433 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2434 the application (usually a Linux kernel) when it is
2437 - CONFIG_SYS_BAUDRATE_TABLE:
2438 List of legal baudrate settings for this board.
2440 - CONFIG_SYS_CONSOLE_INFO_QUIET
2441 Suppress display of console information at boot.
2443 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2444 If the board specific function
2445 extern int overwrite_console (void);
2446 returns 1, the stdin, stderr and stdout are switched to the
2447 serial port, else the settings in the environment are used.
2449 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2450 Enable the call to overwrite_console().
2452 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2453 Enable overwrite of previous console environment settings.
2455 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2456 Begin and End addresses of the area used by the
2459 - CONFIG_SYS_ALT_MEMTEST:
2460 Enable an alternate, more extensive memory test.
2462 - CONFIG_SYS_MEMTEST_SCRATCH:
2463 Scratch address used by the alternate memory test
2464 You only need to set this if address zero isn't writeable
2466 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2467 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2468 this specified memory area will get subtracted from the top
2469 (end) of RAM and won't get "touched" at all by U-Boot. By
2470 fixing up gd->ram_size the Linux kernel should gets passed
2471 the now "corrected" memory size and won't touch it either.
2472 This should work for arch/ppc and arch/powerpc. Only Linux
2473 board ports in arch/powerpc with bootwrapper support that
2474 recalculate the memory size from the SDRAM controller setup
2475 will have to get fixed in Linux additionally.
2477 This option can be used as a workaround for the 440EPx/GRx
2478 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2481 WARNING: Please make sure that this value is a multiple of
2482 the Linux page size (normally 4k). If this is not the case,
2483 then the end address of the Linux memory will be located at a
2484 non page size aligned address and this could cause major
2487 - CONFIG_SYS_TFTP_LOADADDR:
2488 Default load address for network file downloads
2490 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2491 Enable temporary baudrate change while serial download
2493 - CONFIG_SYS_SDRAM_BASE:
2494 Physical start address of SDRAM. _Must_ be 0 here.
2496 - CONFIG_SYS_MBIO_BASE:
2497 Physical start address of Motherboard I/O (if using a
2500 - CONFIG_SYS_FLASH_BASE:
2501 Physical start address of Flash memory.
2503 - CONFIG_SYS_MONITOR_BASE:
2504 Physical start address of boot monitor code (set by
2505 make config files to be same as the text base address
2506 (CONFIG_SYS_TEXT_BASE) used when linking) - same as
2507 CONFIG_SYS_FLASH_BASE when booting from flash.
2509 - CONFIG_SYS_MONITOR_LEN:
2510 Size of memory reserved for monitor code, used to
2511 determine _at_compile_time_ (!) if the environment is
2512 embedded within the U-Boot image, or in a separate
2515 - CONFIG_SYS_MALLOC_LEN:
2516 Size of DRAM reserved for malloc() use.
2518 - CONFIG_SYS_BOOTM_LEN:
2519 Normally compressed uImages are limited to an
2520 uncompressed size of 8 MBytes. If this is not enough,
2521 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2522 to adjust this setting to your needs.
2524 - CONFIG_SYS_BOOTMAPSZ:
2525 Maximum size of memory mapped by the startup code of
2526 the Linux kernel; all data that must be processed by
2527 the Linux kernel (bd_info, boot arguments, FDT blob if
2528 used) must be put below this limit, unless "bootm_low"
2529 enviroment variable is defined and non-zero. In such case
2530 all data for the Linux kernel must be between "bootm_low"
2531 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ. The environment
2532 variable "bootm_mapsize" will override the value of
2533 CONFIG_SYS_BOOTMAPSZ. If CONFIG_SYS_BOOTMAPSZ is undefined,
2534 then the value in "bootm_size" will be used instead.
2536 - CONFIG_SYS_BOOT_RAMDISK_HIGH:
2537 Enable initrd_high functionality. If defined then the
2538 initrd_high feature is enabled and the bootm ramdisk subcommand
2541 - CONFIG_SYS_BOOT_GET_CMDLINE:
2542 Enables allocating and saving kernel cmdline in space between
2543 "bootm_low" and "bootm_low" + BOOTMAPSZ.
2545 - CONFIG_SYS_BOOT_GET_KBD:
2546 Enables allocating and saving a kernel copy of the bd_info in
2547 space between "bootm_low" and "bootm_low" + BOOTMAPSZ.
2549 - CONFIG_SYS_MAX_FLASH_BANKS:
2550 Max number of Flash memory banks
2552 - CONFIG_SYS_MAX_FLASH_SECT:
2553 Max number of sectors on a Flash chip
2555 - CONFIG_SYS_FLASH_ERASE_TOUT:
2556 Timeout for Flash erase operations (in ms)
2558 - CONFIG_SYS_FLASH_WRITE_TOUT:
2559 Timeout for Flash write operations (in ms)
2561 - CONFIG_SYS_FLASH_LOCK_TOUT
2562 Timeout for Flash set sector lock bit operation (in ms)
2564 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2565 Timeout for Flash clear lock bits operation (in ms)
2567 - CONFIG_SYS_FLASH_PROTECTION
2568 If defined, hardware flash sectors protection is used
2569 instead of U-Boot software protection.
2571 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2573 Enable TFTP transfers directly to flash memory;
2574 without this option such a download has to be
2575 performed in two steps: (1) download to RAM, and (2)
2576 copy from RAM to flash.
2578 The two-step approach is usually more reliable, since
2579 you can check if the download worked before you erase
2580 the flash, but in some situations (when system RAM is
2581 too limited to allow for a temporary copy of the
2582 downloaded image) this option may be very useful.
2584 - CONFIG_SYS_FLASH_CFI:
2585 Define if the flash driver uses extra elements in the
2586 common flash structure for storing flash geometry.
2588 - CONFIG_FLASH_CFI_DRIVER
2589 This option also enables the building of the cfi_flash driver
2590 in the drivers directory
2592 - CONFIG_FLASH_CFI_MTD
2593 This option enables the building of the cfi_mtd driver
2594 in the drivers directory. The driver exports CFI flash
2597 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2598 Use buffered writes to flash.
2600 - CONFIG_FLASH_SPANSION_S29WS_N
2601 s29ws-n MirrorBit flash has non-standard addresses for buffered
2604 - CONFIG_SYS_FLASH_QUIET_TEST
2605 If this option is defined, the common CFI flash doesn't
2606 print it's warning upon not recognized FLASH banks. This
2607 is useful, if some of the configured banks are only
2608 optionally available.
2610 - CONFIG_FLASH_SHOW_PROGRESS
2611 If defined (must be an integer), print out countdown
2612 digits and dots. Recommended value: 45 (9..1) for 80
2613 column displays, 15 (3..1) for 40 column displays.
2615 - CONFIG_SYS_RX_ETH_BUFFER:
2616 Defines the number of Ethernet receive buffers. On some
2617 Ethernet controllers it is recommended to set this value
2618 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2619 buffers can be full shortly after enabling the interface
2620 on high Ethernet traffic.
2621 Defaults to 4 if not defined.
2623 - CONFIG_ENV_MAX_ENTRIES
2625 Maximum number of entries in the hash table that is used
2626 internally to store the environment settings. The default
2627 setting is supposed to be generous and should work in most
2628 cases. This setting can be used to tune behaviour; see
2629 lib/hashtable.c for details.
2631 The following definitions that deal with the placement and management
2632 of environment data (variable area); in general, we support the
2633 following configurations:
2635 - CONFIG_BUILD_ENVCRC:
2637 Builds up envcrc with the target environment so that external utils
2638 may easily extract it and embed it in final U-Boot images.
2640 - CONFIG_ENV_IS_IN_FLASH:
2642 Define this if the environment is in flash memory.
2644 a) The environment occupies one whole flash sector, which is
2645 "embedded" in the text segment with the U-Boot code. This
2646 happens usually with "bottom boot sector" or "top boot
2647 sector" type flash chips, which have several smaller
2648 sectors at the start or the end. For instance, such a
2649 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2650 such a case you would place the environment in one of the
2651 4 kB sectors - with U-Boot code before and after it. With
2652 "top boot sector" type flash chips, you would put the
2653 environment in one of the last sectors, leaving a gap
2654 between U-Boot and the environment.
2656 - CONFIG_ENV_OFFSET:
2658 Offset of environment data (variable area) to the
2659 beginning of flash memory; for instance, with bottom boot
2660 type flash chips the second sector can be used: the offset
2661 for this sector is given here.
2663 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2667 This is just another way to specify the start address of
2668 the flash sector containing the environment (instead of
2671 - CONFIG_ENV_SECT_SIZE:
2673 Size of the sector containing the environment.
2676 b) Sometimes flash chips have few, equal sized, BIG sectors.
2677 In such a case you don't want to spend a whole sector for
2682 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2683 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2684 of this flash sector for the environment. This saves
2685 memory for the RAM copy of the environment.
2687 It may also save flash memory if you decide to use this
2688 when your environment is "embedded" within U-Boot code,
2689 since then the remainder of the flash sector could be used
2690 for U-Boot code. It should be pointed out that this is
2691 STRONGLY DISCOURAGED from a robustness point of view:
2692 updating the environment in flash makes it always
2693 necessary to erase the WHOLE sector. If something goes
2694 wrong before the contents has been restored from a copy in
2695 RAM, your target system will be dead.
2697 - CONFIG_ENV_ADDR_REDUND
2698 CONFIG_ENV_SIZE_REDUND
2700 These settings describe a second storage area used to hold
2701 a redundant copy of the environment data, so that there is
2702 a valid backup copy in case there is a power failure during
2703 a "saveenv" operation.
2705 BE CAREFUL! Any changes to the flash layout, and some changes to the
2706 source code will make it necessary to adapt <board>/u-boot.lds*
2710 - CONFIG_ENV_IS_IN_NVRAM:
2712 Define this if you have some non-volatile memory device
2713 (NVRAM, battery buffered SRAM) which you want to use for the
2719 These two #defines are used to determine the memory area you
2720 want to use for environment. It is assumed that this memory
2721 can just be read and written to, without any special
2724 BE CAREFUL! The first access to the environment happens quite early
2725 in U-Boot initalization (when we try to get the setting of for the
2726 console baudrate). You *MUST* have mapped your NVRAM area then, or
2729 Please note that even with NVRAM we still use a copy of the
2730 environment in RAM: we could work on NVRAM directly, but we want to
2731 keep settings there always unmodified except somebody uses "saveenv"
2732 to save the current settings.
2735 - CONFIG_ENV_IS_IN_EEPROM:
2737 Use this if you have an EEPROM or similar serial access
2738 device and a driver for it.
2740 - CONFIG_ENV_OFFSET:
2743 These two #defines specify the offset and size of the
2744 environment area within the total memory of your EEPROM.
2746 - CONFIG_SYS_I2C_EEPROM_ADDR:
2747 If defined, specified the chip address of the EEPROM device.
2748 The default address is zero.
2750 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2751 If defined, the number of bits used to address bytes in a
2752 single page in the EEPROM device. A 64 byte page, for example
2753 would require six bits.
2755 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2756 If defined, the number of milliseconds to delay between
2757 page writes. The default is zero milliseconds.
2759 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2760 The length in bytes of the EEPROM memory array address. Note
2761 that this is NOT the chip address length!
2763 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2764 EEPROM chips that implement "address overflow" are ones
2765 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2766 address and the extra bits end up in the "chip address" bit
2767 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2770 Note that we consider the length of the address field to
2771 still be one byte because the extra address bits are hidden
2772 in the chip address.
2774 - CONFIG_SYS_EEPROM_SIZE:
2775 The size in bytes of the EEPROM device.
2777 - CONFIG_ENV_EEPROM_IS_ON_I2C
2778 define this, if you have I2C and SPI activated, and your
2779 EEPROM, which holds the environment, is on the I2C bus.
2781 - CONFIG_I2C_ENV_EEPROM_BUS
2782 if you have an Environment on an EEPROM reached over
2783 I2C muxes, you can define here, how to reach this
2784 EEPROM. For example:
2786 #define CONFIG_I2C_ENV_EEPROM_BUS "pca9547:70:d\0"
2788 EEPROM which holds the environment, is reached over
2789 a pca9547 i2c mux with address 0x70, channel 3.
2791 - CONFIG_ENV_IS_IN_DATAFLASH:
2793 Define this if you have a DataFlash memory device which you
2794 want to use for the environment.
2796 - CONFIG_ENV_OFFSET:
2800 These three #defines specify the offset and size of the
2801 environment area within the total memory of your DataFlash placed
2802 at the specified address.
2804 - CONFIG_ENV_IS_IN_NAND:
2806 Define this if you have a NAND device which you want to use
2807 for the environment.
2809 - CONFIG_ENV_OFFSET:
2812 These two #defines specify the offset and size of the environment
2813 area within the first NAND device. CONFIG_ENV_OFFSET must be
2814 aligned to an erase block boundary.
2816 - CONFIG_ENV_OFFSET_REDUND (optional):
2818 This setting describes a second storage area of CONFIG_ENV_SIZE
2819 size used to hold a redundant copy of the environment data, so
2820 that there is a valid backup copy in case there is a power failure
2821 during a "saveenv" operation. CONFIG_ENV_OFFSET_RENDUND must be
2822 aligned to an erase block boundary.
2824 - CONFIG_ENV_RANGE (optional):
2826 Specifies the length of the region in which the environment
2827 can be written. This should be a multiple of the NAND device's
2828 block size. Specifying a range with more erase blocks than
2829 are needed to hold CONFIG_ENV_SIZE allows bad blocks within
2830 the range to be avoided.
2832 - CONFIG_ENV_OFFSET_OOB (optional):
2834 Enables support for dynamically retrieving the offset of the
2835 environment from block zero's out-of-band data. The
2836 "nand env.oob" command can be used to record this offset.
2837 Currently, CONFIG_ENV_OFFSET_REDUND is not supported when
2838 using CONFIG_ENV_OFFSET_OOB.
2840 - CONFIG_NAND_ENV_DST
2842 Defines address in RAM to which the nand_spl code should copy the
2843 environment. If redundant environment is used, it will be copied to
2844 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2846 - CONFIG_SYS_SPI_INIT_OFFSET
2848 Defines offset to the initial SPI buffer area in DPRAM. The
2849 area is used at an early stage (ROM part) if the environment
2850 is configured to reside in the SPI EEPROM: We need a 520 byte
2851 scratch DPRAM area. It is used between the two initialization
2852 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2853 to be a good choice since it makes it far enough from the
2854 start of the data area as well as from the stack pointer.
2856 Please note that the environment is read-only until the monitor
2857 has been relocated to RAM and a RAM copy of the environment has been
2858 created; also, when using EEPROM you will have to use getenv_f()
2859 until then to read environment variables.
2861 The environment is protected by a CRC32 checksum. Before the monitor
2862 is relocated into RAM, as a result of a bad CRC you will be working
2863 with the compiled-in default environment - *silently*!!! [This is
2864 necessary, because the first environment variable we need is the
2865 "baudrate" setting for the console - if we have a bad CRC, we don't
2866 have any device yet where we could complain.]
2868 Note: once the monitor has been relocated, then it will complain if
2869 the default environment is used; a new CRC is computed as soon as you
2870 use the "saveenv" command to store a valid environment.
2872 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2873 Echo the inverted Ethernet link state to the fault LED.
2875 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2876 also needs to be defined.
2878 - CONFIG_SYS_FAULT_MII_ADDR:
2879 MII address of the PHY to check for the Ethernet link state.
2881 - CONFIG_NS16550_MIN_FUNCTIONS:
2882 Define this if you desire to only have use of the NS16550_init
2883 and NS16550_putc functions for the serial driver located at
2884 drivers/serial/ns16550.c. This option is useful for saving
2885 space for already greatly restricted images, including but not
2886 limited to NAND_SPL configurations.
2888 Low Level (hardware related) configuration options:
2889 ---------------------------------------------------
2891 - CONFIG_SYS_CACHELINE_SIZE:
2892 Cache Line Size of the CPU.
2894 - CONFIG_SYS_DEFAULT_IMMR:
2895 Default address of the IMMR after system reset.
2897 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2898 and RPXsuper) to be able to adjust the position of
2899 the IMMR register after a reset.
2901 - CONFIG_SYS_CCSRBAR_DEFAULT:
2902 Default (power-on reset) physical address of CCSR on Freescale
2905 - CONFIG_SYS_CCSRBAR:
2906 Virtual address of CCSR. On a 32-bit build, this is typically
2907 the same value as CONFIG_SYS_CCSRBAR_DEFAULT.
2909 CONFIG_SYS_DEFAULT_IMMR must also be set to this value,
2910 for cross-platform code that uses that macro instead.
2912 - CONFIG_SYS_CCSRBAR_PHYS:
2913 Physical address of CCSR. CCSR can be relocated to a new
2914 physical address, if desired. In this case, this macro should
2915 be set to that address. Otherwise, it should be set to the
2916 same value as CONFIG_SYS_CCSRBAR_DEFAULT. For example, CCSR
2917 is typically relocated on 36-bit builds. It is recommended
2918 that this macro be defined via the _HIGH and _LOW macros:
2920 #define CONFIG_SYS_CCSRBAR_PHYS ((CONFIG_SYS_CCSRBAR_PHYS_HIGH
2921 * 1ull) << 32 | CONFIG_SYS_CCSRBAR_PHYS_LOW)
2923 - CONFIG_SYS_CCSRBAR_PHYS_HIGH:
2924 Bits 33-36 of CONFIG_SYS_CCSRBAR_PHYS. This value is typically
2925 either 0 (32-bit build) or 0xF (36-bit build). This macro is
2926 used in assembly code, so it must not contain typecasts or
2927 integer size suffixes (e.g. "ULL").
2929 - CONFIG_SYS_CCSRBAR_PHYS_LOW:
2930 Lower 32-bits of CONFIG_SYS_CCSRBAR_PHYS. This macro is
2931 used in assembly code, so it must not contain typecasts or
2932 integer size suffixes (e.g. "ULL").
2934 - CONFIG_SYS_CCSR_DO_NOT_RELOCATE:
2935 If this macro is defined, then CONFIG_SYS_CCSRBAR_PHYS will be
2936 forced to a value that ensures that CCSR is not relocated.
2938 - Floppy Disk Support:
2939 CONFIG_SYS_FDC_DRIVE_NUMBER
2941 the default drive number (default value 0)
2943 CONFIG_SYS_ISA_IO_STRIDE
2945 defines the spacing between FDC chipset registers
2948 CONFIG_SYS_ISA_IO_OFFSET
2950 defines the offset of register from address. It
2951 depends on which part of the data bus is connected to
2952 the FDC chipset. (default value 0)
2954 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2955 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2958 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2959 fdc_hw_init() is called at the beginning of the FDC
2960 setup. fdc_hw_init() must be provided by the board
2961 source code. It is used to make hardware dependant
2965 Most IDE controllers were designed to be connected with PCI
2966 interface. Only few of them were designed for AHB interface.
2967 When software is doing ATA command and data transfer to
2968 IDE devices through IDE-AHB controller, some additional
2969 registers accessing to these kind of IDE-AHB controller
2972 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2973 DO NOT CHANGE unless you know exactly what you're
2974 doing! (11-4) [MPC8xx/82xx systems only]
2976 - CONFIG_SYS_INIT_RAM_ADDR:
2978 Start address of memory area that can be used for
2979 initial data and stack; please note that this must be
2980 writable memory that is working WITHOUT special
2981 initialization, i. e. you CANNOT use normal RAM which
2982 will become available only after programming the
2983 memory controller and running certain initialization
2986 U-Boot uses the following memory types:
2987 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2988 - MPC824X: data cache
2989 - PPC4xx: data cache
2991 - CONFIG_SYS_GBL_DATA_OFFSET:
2993 Offset of the initial data structure in the memory
2994 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2995 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2996 data is located at the end of the available space
2997 (sometimes written as (CONFIG_SYS_INIT_RAM_SIZE -
2998 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2999 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
3000 CONFIG_SYS_GBL_DATA_OFFSET) downward.
3003 On the MPC824X (or other systems that use the data
3004 cache for initial memory) the address chosen for
3005 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
3006 point to an otherwise UNUSED address space between
3007 the top of RAM and the start of the PCI space.
3009 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
3011 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
3013 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
3015 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
3017 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
3019 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
3021 - CONFIG_SYS_OR_TIMING_SDRAM:
3024 - CONFIG_SYS_MAMR_PTA:
3025 periodic timer for refresh
3027 - CONFIG_SYS_DER: Debug Event Register (37-47)
3029 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
3030 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
3031 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
3032 CONFIG_SYS_BR1_PRELIM:
3033 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
3035 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
3036 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
3037 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
3038 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
3040 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
3041 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
3042 Machine Mode Register and Memory Periodic Timer
3043 Prescaler definitions (SDRAM timing)
3045 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
3046 enable I2C microcode relocation patch (MPC8xx);
3047 define relocation offset in DPRAM [DSP2]
3049 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
3050 enable SMC microcode relocation patch (MPC8xx);
3051 define relocation offset in DPRAM [SMC1]
3053 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
3054 enable SPI microcode relocation patch (MPC8xx);
3055 define relocation offset in DPRAM [SCC4]
3057 - CONFIG_SYS_USE_OSCCLK:
3058 Use OSCM clock mode on MBX8xx board. Be careful,
3059 wrong setting might damage your board. Read
3060 doc/README.MBX before setting this variable!
3062 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
3063 Offset of the bootmode word in DPRAM used by post
3064 (Power On Self Tests). This definition overrides
3065 #define'd default value in commproc.h resp.
3068 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
3069 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
3070 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
3071 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
3072 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
3073 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
3074 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
3075 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
3076 Overrides the default PCI memory map in arch/powerpc/cpu/mpc8260/pci.c if set.
3078 - CONFIG_PCI_DISABLE_PCIE:
3079 Disable PCI-Express on systems where it is supported but not
3083 Chip has SRIO or not
3086 Board has SRIO 1 port available
3089 Board has SRIO 2 port available
3091 - CONFIG_SYS_SRIOn_MEM_VIRT:
3092 Virtual Address of SRIO port 'n' memory region
3094 - CONFIG_SYS_SRIOn_MEM_PHYS:
3095 Physical Address of SRIO port 'n' memory region
3097 - CONFIG_SYS_SRIOn_MEM_SIZE:
3098 Size of SRIO port 'n' memory region
3100 - CONFIG_SYS_NDFC_16
3101 Defined to tell the NDFC that the NAND chip is using a
3104 - CONFIG_SYS_NDFC_EBC0_CFG
3105 Sets the EBC0_CFG register for the NDFC. If not defined
3106 a default value will be used.
3109 Get DDR timing information from an I2C EEPROM. Common
3110 with pluggable memory modules such as SODIMMs
3113 I2C address of the SPD EEPROM
3115 - CONFIG_SYS_SPD_BUS_NUM
3116 If SPD EEPROM is on an I2C bus other than the first
3117 one, specify here. Note that the value must resolve
3118 to something your driver can deal with.
3120 - CONFIG_SYS_DDR_RAW_TIMING
3121 Get DDR timing information from other than SPD. Common with
3122 soldered DDR chips onboard without SPD. DDR raw timing
3123 parameters are extracted from datasheet and hard-coded into
3124 header files or board specific files.
3126 - CONFIG_FSL_DDR_INTERACTIVE
3127 Enable interactive DDR debugging. See doc/README.fsl-ddr.
3129 - CONFIG_SYS_83XX_DDR_USES_CS0
3130 Only for 83xx systems. If specified, then DDR should
3131 be configured using CS0 and CS1 instead of CS2 and CS3.
3133 - CONFIG_ETHER_ON_FEC[12]
3134 Define to enable FEC[12] on a 8xx series processor.
3136 - CONFIG_FEC[12]_PHY
3137 Define to the hardcoded PHY address which corresponds
3138 to the given FEC; i. e.
3139 #define CONFIG_FEC1_PHY 4
3140 means that the PHY with address 4 is connected to FEC1
3142 When set to -1, means to probe for first available.
3144 - CONFIG_FEC[12]_PHY_NORXERR
3145 The PHY does not have a RXERR line (RMII only).
3146 (so program the FEC to ignore it).
3149 Enable RMII mode for all FECs.
3150 Note that this is a global option, we can't
3151 have one FEC in standard MII mode and another in RMII mode.
3153 - CONFIG_CRC32_VERIFY
3154 Add a verify option to the crc32 command.
3157 => crc32 -v <address> <count> <crc32>
3159 Where address/count indicate a memory area
3160 and crc32 is the correct crc32 which the
3164 Add the "loopw" memory command. This only takes effect if
3165 the memory commands are activated globally (CONFIG_CMD_MEM).
3168 Add the "mdc" and "mwc" memory commands. These are cyclic
3173 This command will print 4 bytes (10,11,12,13) each 500 ms.
3175 => mwc.l 100 12345678 10
3176 This command will write 12345678 to address 100 all 10 ms.
3178 This only takes effect if the memory commands are activated
3179 globally (CONFIG_CMD_MEM).
3181 - CONFIG_SKIP_LOWLEVEL_INIT
3182 [ARM, NDS32, MIPS only] If this variable is defined, then certain
3183 low level initializations (like setting up the memory
3184 controller) are omitted and/or U-Boot does not
3185 relocate itself into RAM.
3187 Normally this variable MUST NOT be defined. The only
3188 exception is when U-Boot is loaded (to RAM) by some
3189 other boot loader or by a debugger which performs
3190 these initializations itself.
3193 Modifies the behaviour of start.S when compiling a loader
3194 that is executed before the actual U-Boot. E.g. when
3195 compiling a NAND SPL.
3197 - CONFIG_USE_ARCH_MEMCPY
3198 CONFIG_USE_ARCH_MEMSET
3199 If these options are used a optimized version of memcpy/memset will
3200 be used if available. These functions may be faster under some
3201 conditions but may increase the binary size.
3203 Building the Software:
3204 ======================
3206 Building U-Boot has been tested in several native build environments
3207 and in many different cross environments. Of course we cannot support
3208 all possibly existing versions of cross development tools in all
3209 (potentially obsolete) versions. In case of tool chain problems we
3210 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
3211 which is extensively used to build and test U-Boot.
3213 If you are not using a native environment, it is assumed that you
3214 have GNU cross compiling tools available in your path. In this case,
3215 you must set the environment variable CROSS_COMPILE in your shell.
3216 Note that no changes to the Makefile or any other source files are
3217 necessary. For example using the ELDK on a 4xx CPU, please enter:
3219 $ CROSS_COMPILE=ppc_4xx-
3220 $ export CROSS_COMPILE
3222 Note: If you wish to generate Windows versions of the utilities in
3223 the tools directory you can use the MinGW toolchain
3224 (http://www.mingw.org). Set your HOST tools to the MinGW
3225 toolchain and execute 'make tools'. For example:
3227 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
3229 Binaries such as tools/mkimage.exe will be created which can
3230 be executed on computers running Windows.
3232 U-Boot is intended to be simple to build. After installing the
3233 sources you must configure U-Boot for one specific board type. This
3238 where "NAME_config" is the name of one of the existing configu-
3239 rations; see the main Makefile for supported names.
3241 Note: for some board special configuration names may exist; check if
3242 additional information is available from the board vendor; for
3243 instance, the TQM823L systems are available without (standard)
3244 or with LCD support. You can select such additional "features"
3245 when choosing the configuration, i. e.
3248 - will configure for a plain TQM823L, i. e. no LCD support
3250 make TQM823L_LCD_config
3251 - will configure for a TQM823L with U-Boot console on LCD
3256 Finally, type "make all", and you should get some working U-Boot
3257 images ready for download to / installation on your system:
3259 - "u-boot.bin" is a raw binary image
3260 - "u-boot" is an image in ELF binary format
3261 - "u-boot.srec" is in Motorola S-Record format
3263 By default the build is performed locally and the objects are saved
3264 in the source directory. One of the two methods can be used to change
3265 this behavior and build U-Boot to some external directory:
3267 1. Add O= to the make command line invocations:
3269 make O=/tmp/build distclean
3270 make O=/tmp/build NAME_config
3271 make O=/tmp/build all
3273 2. Set environment variable BUILD_DIR to point to the desired location:
3275 export BUILD_DIR=/tmp/build
3280 Note that the command line "O=" setting overrides the BUILD_DIR environment
3284 Please be aware that the Makefiles assume you are using GNU make, so
3285 for instance on NetBSD you might need to use "gmake" instead of
3289 If the system board that you have is not listed, then you will need
3290 to port U-Boot to your hardware platform. To do this, follow these
3293 1. Add a new configuration option for your board to the toplevel
3294 "Makefile" and to the "MAKEALL" script, using the existing
3295 entries as examples. Note that here and at many other places
3296 boards and other names are listed in alphabetical sort order. Please
3298 2. Create a new directory to hold your board specific code. Add any
3299 files you need. In your board directory, you will need at least
3300 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
3301 3. Create a new configuration file "include/configs/<board>.h" for
3303 3. If you're porting U-Boot to a new CPU, then also create a new
3304 directory to hold your CPU specific code. Add any files you need.
3305 4. Run "make <board>_config" with your new name.
3306 5. Type "make", and you should get a working "u-boot.srec" file
3307 to be installed on your target system.
3308 6. Debug and solve any problems that might arise.
3309 [Of course, this last step is much harder than it sounds.]
3312 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
3313 ==============================================================
3315 If you have modified U-Boot sources (for instance added a new board
3316 or support for new devices, a new CPU, etc.) you are expected to
3317 provide feedback to the other developers. The feedback normally takes
3318 the form of a "patch", i. e. a context diff against a certain (latest
3319 official or latest in the git repository) version of U-Boot sources.
3321 But before you submit such a patch, please verify that your modifi-
3322 cation did not break existing code. At least make sure that *ALL* of
3323 the supported boards compile WITHOUT ANY compiler warnings. To do so,
3324 just run the "MAKEALL" script, which will configure and build U-Boot
3325 for ALL supported system. Be warned, this will take a while. You can
3326 select which (cross) compiler to use by passing a `CROSS_COMPILE'
3327 environment variable to the script, i. e. to use the ELDK cross tools
3330 CROSS_COMPILE=ppc_8xx- MAKEALL
3332 or to build on a native PowerPC system you can type
3334 CROSS_COMPILE=' ' MAKEALL
3336 When using the MAKEALL script, the default behaviour is to build
3337 U-Boot in the source directory. This location can be changed by
3338 setting the BUILD_DIR environment variable. Also, for each target
3339 built, the MAKEALL script saves two log files (<target>.ERR and
3340 <target>.MAKEALL) in the <source dir>/LOG directory. This default
3341 location can be changed by setting the MAKEALL_LOGDIR environment
3342 variable. For example:
3344 export BUILD_DIR=/tmp/build
3345 export MAKEALL_LOGDIR=/tmp/log
3346 CROSS_COMPILE=ppc_8xx- MAKEALL
3348 With the above settings build objects are saved in the /tmp/build,
3349 log files are saved in the /tmp/log and the source tree remains clean
3350 during the whole build process.
3353 See also "U-Boot Porting Guide" below.
3356 Monitor Commands - Overview:
3357 ============================
3359 go - start application at address 'addr'
3360 run - run commands in an environment variable
3361 bootm - boot application image from memory
3362 bootp - boot image via network using BootP/TFTP protocol
3363 tftpboot- boot image via network using TFTP protocol
3364 and env variables "ipaddr" and "serverip"
3365 (and eventually "gatewayip")
3366 tftpput - upload a file via network using TFTP protocol
3367 rarpboot- boot image via network using RARP/TFTP protocol
3368 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
3369 loads - load S-Record file over serial line
3370 loadb - load binary file over serial line (kermit mode)
3372 mm - memory modify (auto-incrementing)
3373 nm - memory modify (constant address)
3374 mw - memory write (fill)
3376 cmp - memory compare
3377 crc32 - checksum calculation
3378 i2c - I2C sub-system
3379 sspi - SPI utility commands
3380 base - print or set address offset
3381 printenv- print environment variables
3382 setenv - set environment variables
3383 saveenv - save environment variables to persistent storage
3384 protect - enable or disable FLASH write protection
3385 erase - erase FLASH memory
3386 flinfo - print FLASH memory information
3387 bdinfo - print Board Info structure
3388 iminfo - print header information for application image
3389 coninfo - print console devices and informations
3390 ide - IDE sub-system
3391 loop - infinite loop on address range
3392 loopw - infinite write loop on address range
3393 mtest - simple RAM test
3394 icache - enable or disable instruction cache
3395 dcache - enable or disable data cache
3396 reset - Perform RESET of the CPU
3397 echo - echo args to console
3398 version - print monitor version
3399 help - print online help
3400 ? - alias for 'help'
3403 Monitor Commands - Detailed Description:
3404 ========================================
3408 For now: just type "help <command>".
3411 Environment Variables:
3412 ======================
3414 U-Boot supports user configuration using Environment Variables which
3415 can be made persistent by saving to Flash memory.
3417 Environment Variables are set using "setenv", printed using
3418 "printenv", and saved to Flash using "saveenv". Using "setenv"
3419 without a value can be used to delete a variable from the
3420 environment. As long as you don't save the environment you are
3421 working with an in-memory copy. In case the Flash area containing the
3422 environment is erased by accident, a default environment is provided.
3424 Some configuration options can be set using Environment Variables.
3426 List of environment variables (most likely not complete):
3428 baudrate - see CONFIG_BAUDRATE
3430 bootdelay - see CONFIG_BOOTDELAY
3432 bootcmd - see CONFIG_BOOTCOMMAND
3434 bootargs - Boot arguments when booting an RTOS image
3436 bootfile - Name of the image to load with TFTP
3438 bootm_low - Memory range available for image processing in the bootm
3439 command can be restricted. This variable is given as
3440 a hexadecimal number and defines lowest address allowed
3441 for use by the bootm command. See also "bootm_size"
3442 environment variable. Address defined by "bootm_low" is
3443 also the base of the initial memory mapping for the Linux
3444 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ and
3447 bootm_mapsize - Size of the initial memory mapping for the Linux kernel.
3448 This variable is given as a hexadecimal number and it
3449 defines the size of the memory region starting at base
3450 address bootm_low that is accessible by the Linux kernel
3451 during early boot. If unset, CONFIG_SYS_BOOTMAPSZ is used
3452 as the default value if it is defined, and bootm_size is
3455 bootm_size - Memory range available for image processing in the bootm
3456 command can be restricted. This variable is given as
3457 a hexadecimal number and defines the size of the region
3458 allowed for use by the bootm command. See also "bootm_low"
3459 environment variable.
3461 updatefile - Location of the software update file on a TFTP server, used
3462 by the automatic software update feature. Please refer to
3463 documentation in doc/README.update for more details.
3465 autoload - if set to "no" (any string beginning with 'n'),
3466 "bootp" will just load perform a lookup of the
3467 configuration from the BOOTP server, but not try to
3468 load any image using TFTP
3470 autostart - if set to "yes", an image loaded using the "bootp",
3471 "rarpboot", "tftpboot" or "diskboot" commands will
3472 be automatically started (by internally calling
3475 If set to "no", a standalone image passed to the
3476 "bootm" command will be copied to the load address
3477 (and eventually uncompressed), but NOT be started.
3478 This can be used to load and uncompress arbitrary
3481 fdt_high - if set this restricts the maximum address that the
3482 flattened device tree will be copied into upon boot.
3483 If this is set to the special value 0xFFFFFFFF then
3484 the fdt will not be copied at all on boot. For this
3485 to work it must reside in writable memory, have
3486 sufficient padding on the end of it for u-boot to
3487 add the information it needs into it, and the memory
3488 must be accessible by the kernel.
3490 i2cfast - (PPC405GP|PPC405EP only)
3491 if set to 'y' configures Linux I2C driver for fast
3492 mode (400kHZ). This environment variable is used in
3493 initialization code. So, for changes to be effective
3494 it must be saved and board must be reset.
3496 initrd_high - restrict positioning of initrd images:
3497 If this variable is not set, initrd images will be
3498 copied to the highest possible address in RAM; this
3499 is usually what you want since it allows for
3500 maximum initrd size. If for some reason you want to
3501 make sure that the initrd image is loaded below the
3502 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3503 variable to a value of "no" or "off" or "0".
3504 Alternatively, you can set it to a maximum upper
3505 address to use (U-Boot will still check that it
3506 does not overwrite the U-Boot stack and data).
3508 For instance, when you have a system with 16 MB
3509 RAM, and want to reserve 4 MB from use by Linux,
3510 you can do this by adding "mem=12M" to the value of
3511 the "bootargs" variable. However, now you must make
3512 sure that the initrd image is placed in the first
3513 12 MB as well - this can be done with
3515 setenv initrd_high 00c00000
3517 If you set initrd_high to 0xFFFFFFFF, this is an
3518 indication to U-Boot that all addresses are legal
3519 for the Linux kernel, including addresses in flash
3520 memory. In this case U-Boot will NOT COPY the
3521 ramdisk at all. This may be useful to reduce the
3522 boot time on your system, but requires that this
3523 feature is supported by your Linux kernel.
3525 ipaddr - IP address; needed for tftpboot command
3527 loadaddr - Default load address for commands like "bootp",
3528 "rarpboot", "tftpboot", "loadb" or "diskboot"
3530 loads_echo - see CONFIG_LOADS_ECHO
3532 serverip - TFTP server IP address; needed for tftpboot command
3534 bootretry - see CONFIG_BOOT_RETRY_TIME
3536 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3538 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3540 ethprime - controls which interface is used first.
3542 ethact - controls which interface is currently active.
3543 For example you can do the following
3545 => setenv ethact FEC
3546 => ping 192.168.0.1 # traffic sent on FEC
3547 => setenv ethact SCC
3548 => ping 10.0.0.1 # traffic sent on SCC
3550 ethrotate - When set to "no" U-Boot does not go through all
3551 available network interfaces.
3552 It just stays at the currently selected interface.
3554 netretry - When set to "no" each network operation will
3555 either succeed or fail without retrying.
3556 When set to "once" the network operation will
3557 fail when all the available network interfaces
3558 are tried once without success.
3559 Useful on scripts which control the retry operation
3562 npe_ucode - set load address for the NPE microcode
3564 tftpsrcport - If this is set, the value is used for TFTP's
3567 tftpdstport - If this is set, the value is used for TFTP's UDP
3568 destination port instead of the Well Know Port 69.
3570 tftpblocksize - Block size to use for TFTP transfers; if not set,
3571 we use the TFTP server's default block size
3573 tftptimeout - Retransmission timeout for TFTP packets (in milli-
3574 seconds, minimum value is 1000 = 1 second). Defines
3575 when a packet is considered to be lost so it has to
3576 be retransmitted. The default is 5000 = 5 seconds.
3577 Lowering this value may make downloads succeed
3578 faster in networks with high packet loss rates or
3579 with unreliable TFTP servers.
3581 vlan - When set to a value < 4095 the traffic over
3582 Ethernet is encapsulated/received over 802.1q
3585 The following image location variables contain the location of images
3586 used in booting. The "Image" column gives the role of the image and is
3587 not an environment variable name. The other columns are environment
3588 variable names. "File Name" gives the name of the file on a TFTP
3589 server, "RAM Address" gives the location in RAM the image will be
3590 loaded to, and "Flash Location" gives the image's address in NOR
3591 flash or offset in NAND flash.
3593 *Note* - these variables don't have to be defined for all boards, some
3594 boards currenlty use other variables for these purposes, and some
3595 boards use these variables for other purposes.
3597 Image File Name RAM Address Flash Location
3598 ----- --------- ----------- --------------
3599 u-boot u-boot u-boot_addr_r u-boot_addr
3600 Linux kernel bootfile kernel_addr_r kernel_addr
3601 device tree blob fdtfile fdt_addr_r fdt_addr
3602 ramdisk ramdiskfile ramdisk_addr_r ramdisk_addr
3604 The following environment variables may be used and automatically
3605 updated by the network boot commands ("bootp" and "rarpboot"),
3606 depending the information provided by your boot server:
3608 bootfile - see above
3609 dnsip - IP address of your Domain Name Server
3610 dnsip2 - IP address of your secondary Domain Name Server
3611 gatewayip - IP address of the Gateway (Router) to use
3612 hostname - Target hostname
3614 netmask - Subnet Mask
3615 rootpath - Pathname of the root filesystem on the NFS server
3616 serverip - see above
3619 There are two special Environment Variables:
3621 serial# - contains hardware identification information such
3622 as type string and/or serial number
3623 ethaddr - Ethernet address
3625 These variables can be set only once (usually during manufacturing of
3626 the board). U-Boot refuses to delete or overwrite these variables
3627 once they have been set once.
3630 Further special Environment Variables:
3632 ver - Contains the U-Boot version string as printed
3633 with the "version" command. This variable is
3634 readonly (see CONFIG_VERSION_VARIABLE).
3637 Please note that changes to some configuration parameters may take
3638 only effect after the next boot (yes, that's just like Windoze :-).
3641 Command Line Parsing:
3642 =====================
3644 There are two different command line parsers available with U-Boot:
3645 the old "simple" one, and the much more powerful "hush" shell:
3647 Old, simple command line parser:
3648 --------------------------------
3650 - supports environment variables (through setenv / saveenv commands)
3651 - several commands on one line, separated by ';'
3652 - variable substitution using "... ${name} ..." syntax
3653 - special characters ('$', ';') can be escaped by prefixing with '\',
3655 setenv bootcmd bootm \${address}
3656 - You can also escape text by enclosing in single apostrophes, for example:
3657 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3662 - similar to Bourne shell, with control structures like
3663 if...then...else...fi, for...do...done; while...do...done,
3664 until...do...done, ...
3665 - supports environment ("global") variables (through setenv / saveenv
3666 commands) and local shell variables (through standard shell syntax
3667 "name=value"); only environment variables can be used with "run"
3673 (1) If a command line (or an environment variable executed by a "run"
3674 command) contains several commands separated by semicolon, and
3675 one of these commands fails, then the remaining commands will be
3678 (2) If you execute several variables with one call to run (i. e.
3679 calling run with a list of variables as arguments), any failing
3680 command will cause "run" to terminate, i. e. the remaining
3681 variables are not executed.
3683 Note for Redundant Ethernet Interfaces:
3684 =======================================
3686 Some boards come with redundant Ethernet interfaces; U-Boot supports
3687 such configurations and is capable of automatic selection of a
3688 "working" interface when needed. MAC assignment works as follows:
3690 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3691 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3692 "eth1addr" (=>eth1), "eth2addr", ...
3694 If the network interface stores some valid MAC address (for instance
3695 in SROM), this is used as default address if there is NO correspon-
3696 ding setting in the environment; if the corresponding environment
3697 variable is set, this overrides the settings in the card; that means:
3699 o If the SROM has a valid MAC address, and there is no address in the
3700 environment, the SROM's address is used.
3702 o If there is no valid address in the SROM, and a definition in the
3703 environment exists, then the value from the environment variable is
3706 o If both the SROM and the environment contain a MAC address, and
3707 both addresses are the same, this MAC address is used.
3709 o If both the SROM and the environment contain a MAC address, and the
3710 addresses differ, the value from the environment is used and a
3713 o If neither SROM nor the environment contain a MAC address, an error
3716 If Ethernet drivers implement the 'write_hwaddr' function, valid MAC addresses
3717 will be programmed into hardware as part of the initialization process. This
3718 may be skipped by setting the appropriate 'ethmacskip' environment variable.
3719 The naming convention is as follows:
3720 "ethmacskip" (=>eth0), "eth1macskip" (=>eth1) etc.
3725 U-Boot is capable of booting (and performing other auxiliary operations on)
3726 images in two formats:
3728 New uImage format (FIT)
3729 -----------------------
3731 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3732 to Flattened Device Tree). It allows the use of images with multiple
3733 components (several kernels, ramdisks, etc.), with contents protected by
3734 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3740 Old image format is based on binary files which can be basically anything,
3741 preceded by a special header; see the definitions in include/image.h for
3742 details; basically, the header defines the following image properties:
3744 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3745 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3746 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3747 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3749 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3750 IA64, MIPS, NDS32, Nios II, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3751 Currently supported: ARM, AVR32, Intel x86, MIPS, NDS32, Nios II, PowerPC).
3752 * Compression Type (uncompressed, gzip, bzip2)
3758 The header is marked by a special Magic Number, and both the header
3759 and the data portions of the image are secured against corruption by
3766 Although U-Boot should support any OS or standalone application
3767 easily, the main focus has always been on Linux during the design of
3770 U-Boot includes many features that so far have been part of some
3771 special "boot loader" code within the Linux kernel. Also, any
3772 "initrd" images to be used are no longer part of one big Linux image;
3773 instead, kernel and "initrd" are separate images. This implementation
3774 serves several purposes:
3776 - the same features can be used for other OS or standalone
3777 applications (for instance: using compressed images to reduce the
3778 Flash memory footprint)
3780 - it becomes much easier to port new Linux kernel versions because
3781 lots of low-level, hardware dependent stuff are done by U-Boot
3783 - the same Linux kernel image can now be used with different "initrd"
3784 images; of course this also means that different kernel images can
3785 be run with the same "initrd". This makes testing easier (you don't
3786 have to build a new "zImage.initrd" Linux image when you just
3787 change a file in your "initrd"). Also, a field-upgrade of the
3788 software is easier now.
3794 Porting Linux to U-Boot based systems:
3795 ---------------------------------------
3797 U-Boot cannot save you from doing all the necessary modifications to
3798 configure the Linux device drivers for use with your target hardware
3799 (no, we don't intend to provide a full virtual machine interface to
3802 But now you can ignore ALL boot loader code (in arch/powerpc/mbxboot).
3804 Just make sure your machine specific header file (for instance
3805 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3806 Information structure as we define in include/asm-<arch>/u-boot.h,
3807 and make sure that your definition of IMAP_ADDR uses the same value
3808 as your U-Boot configuration in CONFIG_SYS_IMMR.
3811 Configuring the Linux kernel:
3812 -----------------------------
3814 No specific requirements for U-Boot. Make sure you have some root
3815 device (initial ramdisk, NFS) for your target system.
3818 Building a Linux Image:
3819 -----------------------
3821 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3822 not used. If you use recent kernel source, a new build target
3823 "uImage" will exist which automatically builds an image usable by
3824 U-Boot. Most older kernels also have support for a "pImage" target,
3825 which was introduced for our predecessor project PPCBoot and uses a
3826 100% compatible format.
3835 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3836 encapsulate a compressed Linux kernel image with header information,
3837 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3839 * build a standard "vmlinux" kernel image (in ELF binary format):
3841 * convert the kernel into a raw binary image:
3843 ${CROSS_COMPILE}-objcopy -O binary \
3844 -R .note -R .comment \
3845 -S vmlinux linux.bin
3847 * compress the binary image:
3851 * package compressed binary image for U-Boot:
3853 mkimage -A ppc -O linux -T kernel -C gzip \
3854 -a 0 -e 0 -n "Linux Kernel Image" \
3855 -d linux.bin.gz uImage
3858 The "mkimage" tool can also be used to create ramdisk images for use
3859 with U-Boot, either separated from the Linux kernel image, or
3860 combined into one file. "mkimage" encapsulates the images with a 64
3861 byte header containing information about target architecture,
3862 operating system, image type, compression method, entry points, time
3863 stamp, CRC32 checksums, etc.
3865 "mkimage" can be called in two ways: to verify existing images and
3866 print the header information, or to build new images.
3868 In the first form (with "-l" option) mkimage lists the information
3869 contained in the header of an existing U-Boot image; this includes
3870 checksum verification:
3872 tools/mkimage -l image
3873 -l ==> list image header information
3875 The second form (with "-d" option) is used to build a U-Boot image
3876 from a "data file" which is used as image payload:
3878 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3879 -n name -d data_file image
3880 -A ==> set architecture to 'arch'
3881 -O ==> set operating system to 'os'
3882 -T ==> set image type to 'type'
3883 -C ==> set compression type 'comp'
3884 -a ==> set load address to 'addr' (hex)
3885 -e ==> set entry point to 'ep' (hex)
3886 -n ==> set image name to 'name'
3887 -d ==> use image data from 'datafile'
3889 Right now, all Linux kernels for PowerPC systems use the same load
3890 address (0x00000000), but the entry point address depends on the
3893 - 2.2.x kernels have the entry point at 0x0000000C,
3894 - 2.3.x and later kernels have the entry point at 0x00000000.
3896 So a typical call to build a U-Boot image would read:
3898 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3899 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3900 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz \
3901 > examples/uImage.TQM850L
3902 Image Name: 2.4.4 kernel for TQM850L
3903 Created: Wed Jul 19 02:34:59 2000
3904 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3905 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3906 Load Address: 0x00000000
3907 Entry Point: 0x00000000
3909 To verify the contents of the image (or check for corruption):
3911 -> tools/mkimage -l examples/uImage.TQM850L
3912 Image Name: 2.4.4 kernel for TQM850L
3913 Created: Wed Jul 19 02:34:59 2000
3914 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3915 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3916 Load Address: 0x00000000
3917 Entry Point: 0x00000000
3919 NOTE: for embedded systems where boot time is critical you can trade
3920 speed for memory and install an UNCOMPRESSED image instead: this
3921 needs more space in Flash, but boots much faster since it does not
3922 need to be uncompressed:
3924 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux.gz
3925 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3926 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3927 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/powerpc/coffboot/vmlinux \
3928 > examples/uImage.TQM850L-uncompressed
3929 Image Name: 2.4.4 kernel for TQM850L
3930 Created: Wed Jul 19 02:34:59 2000
3931 Image Type: PowerPC Linux Kernel Image (uncompressed)
3932 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3933 Load Address: 0x00000000
3934 Entry Point: 0x00000000
3937 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3938 when your kernel is intended to use an initial ramdisk:
3940 -> tools/mkimage -n 'Simple Ramdisk Image' \
3941 > -A ppc -O linux -T ramdisk -C gzip \
3942 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3943 Image Name: Simple Ramdisk Image
3944 Created: Wed Jan 12 14:01:50 2000
3945 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3946 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3947 Load Address: 0x00000000
3948 Entry Point: 0x00000000
3951 Installing a Linux Image:
3952 -------------------------
3954 To downloading a U-Boot image over the serial (console) interface,
3955 you must convert the image to S-Record format:
3957 objcopy -I binary -O srec examples/image examples/image.srec
3959 The 'objcopy' does not understand the information in the U-Boot
3960 image header, so the resulting S-Record file will be relative to
3961 address 0x00000000. To load it to a given address, you need to
3962 specify the target address as 'offset' parameter with the 'loads'
3965 Example: install the image to address 0x40100000 (which on the
3966 TQM8xxL is in the first Flash bank):
3968 => erase 40100000 401FFFFF
3974 ## Ready for S-Record download ...
3975 ~>examples/image.srec
3976 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3978 15989 15990 15991 15992
3979 [file transfer complete]
3981 ## Start Addr = 0x00000000
3984 You can check the success of the download using the 'iminfo' command;
3985 this includes a checksum verification so you can be sure no data
3986 corruption happened:
3990 ## Checking Image at 40100000 ...
3991 Image Name: 2.2.13 for initrd on TQM850L
3992 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3993 Data Size: 335725 Bytes = 327 kB = 0 MB
3994 Load Address: 00000000
3995 Entry Point: 0000000c
3996 Verifying Checksum ... OK
4002 The "bootm" command is used to boot an application that is stored in
4003 memory (RAM or Flash). In case of a Linux kernel image, the contents
4004 of the "bootargs" environment variable is passed to the kernel as
4005 parameters. You can check and modify this variable using the
4006 "printenv" and "setenv" commands:
4009 => printenv bootargs
4010 bootargs=root=/dev/ram
4012 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4014 => printenv bootargs
4015 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4018 ## Booting Linux kernel at 40020000 ...
4019 Image Name: 2.2.13 for NFS on TQM850L
4020 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4021 Data Size: 381681 Bytes = 372 kB = 0 MB
4022 Load Address: 00000000
4023 Entry Point: 0000000c
4024 Verifying Checksum ... OK
4025 Uncompressing Kernel Image ... OK
4026 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
4027 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
4028 time_init: decrementer frequency = 187500000/60
4029 Calibrating delay loop... 49.77 BogoMIPS
4030 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
4033 If you want to boot a Linux kernel with initial RAM disk, you pass
4034 the memory addresses of both the kernel and the initrd image (PPBCOOT
4035 format!) to the "bootm" command:
4037 => imi 40100000 40200000
4039 ## Checking Image at 40100000 ...
4040 Image Name: 2.2.13 for initrd on TQM850L
4041 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4042 Data Size: 335725 Bytes = 327 kB = 0 MB
4043 Load Address: 00000000
4044 Entry Point: 0000000c
4045 Verifying Checksum ... OK
4047 ## Checking Image at 40200000 ...
4048 Image Name: Simple Ramdisk Image
4049 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4050 Data Size: 566530 Bytes = 553 kB = 0 MB
4051 Load Address: 00000000
4052 Entry Point: 00000000
4053 Verifying Checksum ... OK
4055 => bootm 40100000 40200000
4056 ## Booting Linux kernel at 40100000 ...
4057 Image Name: 2.2.13 for initrd on TQM850L
4058 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4059 Data Size: 335725 Bytes = 327 kB = 0 MB
4060 Load Address: 00000000
4061 Entry Point: 0000000c
4062 Verifying Checksum ... OK
4063 Uncompressing Kernel Image ... OK
4064 ## Loading RAMDisk Image at 40200000 ...
4065 Image Name: Simple Ramdisk Image
4066 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
4067 Data Size: 566530 Bytes = 553 kB = 0 MB
4068 Load Address: 00000000
4069 Entry Point: 00000000
4070 Verifying Checksum ... OK
4071 Loading Ramdisk ... OK
4072 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
4073 Boot arguments: root=/dev/ram
4074 time_init: decrementer frequency = 187500000/60
4075 Calibrating delay loop... 49.77 BogoMIPS
4077 RAMDISK: Compressed image found at block 0
4078 VFS: Mounted root (ext2 filesystem).
4082 Boot Linux and pass a flat device tree:
4085 First, U-Boot must be compiled with the appropriate defines. See the section
4086 titled "Linux Kernel Interface" above for a more in depth explanation. The
4087 following is an example of how to start a kernel and pass an updated
4093 oft=oftrees/mpc8540ads.dtb
4094 => tftp $oftaddr $oft
4095 Speed: 1000, full duplex
4097 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
4098 Filename 'oftrees/mpc8540ads.dtb'.
4099 Load address: 0x300000
4102 Bytes transferred = 4106 (100a hex)
4103 => tftp $loadaddr $bootfile
4104 Speed: 1000, full duplex
4106 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
4108 Load address: 0x200000
4109 Loading:############
4111 Bytes transferred = 1029407 (fb51f hex)
4116 => bootm $loadaddr - $oftaddr
4117 ## Booting image at 00200000 ...
4118 Image Name: Linux-2.6.17-dirty
4119 Image Type: PowerPC Linux Kernel Image (gzip compressed)
4120 Data Size: 1029343 Bytes = 1005.2 kB
4121 Load Address: 00000000
4122 Entry Point: 00000000
4123 Verifying Checksum ... OK
4124 Uncompressing Kernel Image ... OK
4125 Booting using flat device tree at 0x300000
4126 Using MPC85xx ADS machine description
4127 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
4131 More About U-Boot Image Types:
4132 ------------------------------
4134 U-Boot supports the following image types:
4136 "Standalone Programs" are directly runnable in the environment
4137 provided by U-Boot; it is expected that (if they behave
4138 well) you can continue to work in U-Boot after return from
4139 the Standalone Program.
4140 "OS Kernel Images" are usually images of some Embedded OS which
4141 will take over control completely. Usually these programs
4142 will install their own set of exception handlers, device
4143 drivers, set up the MMU, etc. - this means, that you cannot
4144 expect to re-enter U-Boot except by resetting the CPU.
4145 "RAMDisk Images" are more or less just data blocks, and their
4146 parameters (address, size) are passed to an OS kernel that is
4148 "Multi-File Images" contain several images, typically an OS
4149 (Linux) kernel image and one or more data images like
4150 RAMDisks. This construct is useful for instance when you want
4151 to boot over the network using BOOTP etc., where the boot
4152 server provides just a single image file, but you want to get
4153 for instance an OS kernel and a RAMDisk image.
4155 "Multi-File Images" start with a list of image sizes, each
4156 image size (in bytes) specified by an "uint32_t" in network
4157 byte order. This list is terminated by an "(uint32_t)0".
4158 Immediately after the terminating 0 follow the images, one by
4159 one, all aligned on "uint32_t" boundaries (size rounded up to
4160 a multiple of 4 bytes).
4162 "Firmware Images" are binary images containing firmware (like
4163 U-Boot or FPGA images) which usually will be programmed to
4166 "Script files" are command sequences that will be executed by
4167 U-Boot's command interpreter; this feature is especially
4168 useful when you configure U-Boot to use a real shell (hush)
4169 as command interpreter.
4175 One of the features of U-Boot is that you can dynamically load and
4176 run "standalone" applications, which can use some resources of
4177 U-Boot like console I/O functions or interrupt services.
4179 Two simple examples are included with the sources:
4184 'examples/hello_world.c' contains a small "Hello World" Demo
4185 application; it is automatically compiled when you build U-Boot.
4186 It's configured to run at address 0x00040004, so you can play with it
4190 ## Ready for S-Record download ...
4191 ~>examples/hello_world.srec
4192 1 2 3 4 5 6 7 8 9 10 11 ...
4193 [file transfer complete]
4195 ## Start Addr = 0x00040004
4197 => go 40004 Hello World! This is a test.
4198 ## Starting application at 0x00040004 ...
4209 Hit any key to exit ...
4211 ## Application terminated, rc = 0x0
4213 Another example, which demonstrates how to register a CPM interrupt
4214 handler with the U-Boot code, can be found in 'examples/timer.c'.
4215 Here, a CPM timer is set up to generate an interrupt every second.
4216 The interrupt service routine is trivial, just printing a '.'
4217 character, but this is just a demo program. The application can be
4218 controlled by the following keys:
4220 ? - print current values og the CPM Timer registers
4221 b - enable interrupts and start timer
4222 e - stop timer and disable interrupts
4223 q - quit application
4226 ## Ready for S-Record download ...
4227 ~>examples/timer.srec
4228 1 2 3 4 5 6 7 8 9 10 11 ...
4229 [file transfer complete]
4231 ## Start Addr = 0x00040004
4234 ## Starting application at 0x00040004 ...
4237 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
4240 [q, b, e, ?] Set interval 1000000 us
4243 [q, b, e, ?] ........
4244 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
4247 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
4250 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
4253 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
4255 [q, b, e, ?] ...Stopping timer
4257 [q, b, e, ?] ## Application terminated, rc = 0x0
4263 Over time, many people have reported problems when trying to use the
4264 "minicom" terminal emulation program for serial download. I (wd)
4265 consider minicom to be broken, and recommend not to use it. Under
4266 Unix, I recommend to use C-Kermit for general purpose use (and
4267 especially for kermit binary protocol download ("loadb" command), and
4268 use "cu" for S-Record download ("loads" command).
4270 Nevertheless, if you absolutely want to use it try adding this
4271 configuration to your "File transfer protocols" section:
4273 Name Program Name U/D FullScr IO-Red. Multi
4274 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
4275 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
4281 Starting at version 0.9.2, U-Boot supports NetBSD both as host
4282 (build U-Boot) and target system (boots NetBSD/mpc8xx).
4284 Building requires a cross environment; it is known to work on
4285 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
4286 need gmake since the Makefiles are not compatible with BSD make).
4287 Note that the cross-powerpc package does not install include files;
4288 attempting to build U-Boot will fail because <machine/ansi.h> is
4289 missing. This file has to be installed and patched manually:
4291 # cd /usr/pkg/cross/powerpc-netbsd/include
4293 # ln -s powerpc machine
4294 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
4295 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
4297 Native builds *don't* work due to incompatibilities between native
4298 and U-Boot include files.
4300 Booting assumes that (the first part of) the image booted is a
4301 stage-2 loader which in turn loads and then invokes the kernel
4302 proper. Loader sources will eventually appear in the NetBSD source
4303 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
4304 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
4307 Implementation Internals:
4308 =========================
4310 The following is not intended to be a complete description of every
4311 implementation detail. However, it should help to understand the
4312 inner workings of U-Boot and make it easier to port it to custom
4316 Initial Stack, Global Data:
4317 ---------------------------
4319 The implementation of U-Boot is complicated by the fact that U-Boot
4320 starts running out of ROM (flash memory), usually without access to
4321 system RAM (because the memory controller is not initialized yet).
4322 This means that we don't have writable Data or BSS segments, and BSS
4323 is not initialized as zero. To be able to get a C environment working
4324 at all, we have to allocate at least a minimal stack. Implementation
4325 options for this are defined and restricted by the CPU used: Some CPU
4326 models provide on-chip memory (like the IMMR area on MPC8xx and
4327 MPC826x processors), on others (parts of) the data cache can be
4328 locked as (mis-) used as memory, etc.
4330 Chris Hallinan posted a good summary of these issues to the
4331 U-Boot mailing list:
4333 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
4334 From: "Chris Hallinan" <clh@net1plus.com>
4335 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
4338 Correct me if I'm wrong, folks, but the way I understand it
4339 is this: Using DCACHE as initial RAM for Stack, etc, does not
4340 require any physical RAM backing up the cache. The cleverness
4341 is that the cache is being used as a temporary supply of
4342 necessary storage before the SDRAM controller is setup. It's
4343 beyond the scope of this list to explain the details, but you
4344 can see how this works by studying the cache architecture and
4345 operation in the architecture and processor-specific manuals.
4347 OCM is On Chip Memory, which I believe the 405GP has 4K. It
4348 is another option for the system designer to use as an
4349 initial stack/RAM area prior to SDRAM being available. Either
4350 option should work for you. Using CS 4 should be fine if your
4351 board designers haven't used it for something that would
4352 cause you grief during the initial boot! It is frequently not
4355 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
4356 with your processor/board/system design. The default value
4357 you will find in any recent u-boot distribution in
4358 walnut.h should work for you. I'd set it to a value larger
4359 than your SDRAM module. If you have a 64MB SDRAM module, set
4360 it above 400_0000. Just make sure your board has no resources
4361 that are supposed to respond to that address! That code in
4362 start.S has been around a while and should work as is when
4363 you get the config right.
4368 It is essential to remember this, since it has some impact on the C
4369 code for the initialization procedures:
4371 * Initialized global data (data segment) is read-only. Do not attempt
4374 * Do not use any uninitialized global data (or implicitely initialized
4375 as zero data - BSS segment) at all - this is undefined, initiali-
4376 zation is performed later (when relocating to RAM).
4378 * Stack space is very limited. Avoid big data buffers or things like
4381 Having only the stack as writable memory limits means we cannot use
4382 normal global data to share information beween the code. But it
4383 turned out that the implementation of U-Boot can be greatly
4384 simplified by making a global data structure (gd_t) available to all
4385 functions. We could pass a pointer to this data as argument to _all_
4386 functions, but this would bloat the code. Instead we use a feature of
4387 the GCC compiler (Global Register Variables) to share the data: we
4388 place a pointer (gd) to the global data into a register which we
4389 reserve for this purpose.
4391 When choosing a register for such a purpose we are restricted by the
4392 relevant (E)ABI specifications for the current architecture, and by
4393 GCC's implementation.
4395 For PowerPC, the following registers have specific use:
4397 R2: reserved for system use
4398 R3-R4: parameter passing and return values
4399 R5-R10: parameter passing
4400 R13: small data area pointer
4404 (U-Boot also uses R12 as internal GOT pointer. r12
4405 is a volatile register so r12 needs to be reset when
4406 going back and forth between asm and C)
4408 ==> U-Boot will use R2 to hold a pointer to the global data
4410 Note: on PPC, we could use a static initializer (since the
4411 address of the global data structure is known at compile time),
4412 but it turned out that reserving a register results in somewhat
4413 smaller code - although the code savings are not that big (on
4414 average for all boards 752 bytes for the whole U-Boot image,
4415 624 text + 127 data).
4417 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
4418 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
4420 ==> U-Boot will use P3 to hold a pointer to the global data
4422 On ARM, the following registers are used:
4424 R0: function argument word/integer result
4425 R1-R3: function argument word
4427 R10: stack limit (used only if stack checking if enabled)
4428 R11: argument (frame) pointer
4429 R12: temporary workspace
4432 R15: program counter
4434 ==> U-Boot will use R8 to hold a pointer to the global data
4436 On Nios II, the ABI is documented here:
4437 http://www.altera.com/literature/hb/nios2/n2cpu_nii51016.pdf
4439 ==> U-Boot will use gp to hold a pointer to the global data
4441 Note: on Nios II, we give "-G0" option to gcc and don't use gp
4442 to access small data sections, so gp is free.
4444 On NDS32, the following registers are used:
4446 R0-R1: argument/return
4448 R15: temporary register for assembler
4449 R16: trampoline register
4450 R28: frame pointer (FP)
4451 R29: global pointer (GP)
4452 R30: link register (LP)
4453 R31: stack pointer (SP)
4454 PC: program counter (PC)
4456 ==> U-Boot will use R10 to hold a pointer to the global data
4458 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
4459 or current versions of GCC may "optimize" the code too much.
4464 U-Boot runs in system state and uses physical addresses, i.e. the
4465 MMU is not used either for address mapping nor for memory protection.
4467 The available memory is mapped to fixed addresses using the memory
4468 controller. In this process, a contiguous block is formed for each
4469 memory type (Flash, SDRAM, SRAM), even when it consists of several
4470 physical memory banks.
4472 U-Boot is installed in the first 128 kB of the first Flash bank (on
4473 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
4474 booting and sizing and initializing DRAM, the code relocates itself
4475 to the upper end of DRAM. Immediately below the U-Boot code some
4476 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
4477 configuration setting]. Below that, a structure with global Board
4478 Info data is placed, followed by the stack (growing downward).
4480 Additionally, some exception handler code is copied to the low 8 kB
4481 of DRAM (0x00000000 ... 0x00001FFF).
4483 So a typical memory configuration with 16 MB of DRAM could look like
4486 0x0000 0000 Exception Vector code
4489 0x0000 2000 Free for Application Use
4495 0x00FB FF20 Monitor Stack (Growing downward)
4496 0x00FB FFAC Board Info Data and permanent copy of global data
4497 0x00FC 0000 Malloc Arena
4500 0x00FE 0000 RAM Copy of Monitor Code
4501 ... eventually: LCD or video framebuffer
4502 ... eventually: pRAM (Protected RAM - unchanged by reset)
4503 0x00FF FFFF [End of RAM]
4506 System Initialization:
4507 ----------------------
4509 In the reset configuration, U-Boot starts at the reset entry point
4510 (on most PowerPC systems at address 0x00000100). Because of the reset
4511 configuration for CS0# this is a mirror of the onboard Flash memory.
4512 To be able to re-map memory U-Boot then jumps to its link address.
4513 To be able to implement the initialization code in C, a (small!)
4514 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4515 which provide such a feature like MPC8xx or MPC8260), or in a locked
4516 part of the data cache. After that, U-Boot initializes the CPU core,
4517 the caches and the SIU.
4519 Next, all (potentially) available memory banks are mapped using a
4520 preliminary mapping. For example, we put them on 512 MB boundaries
4521 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4522 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4523 programmed for SDRAM access. Using the temporary configuration, a
4524 simple memory test is run that determines the size of the SDRAM
4527 When there is more than one SDRAM bank, and the banks are of
4528 different size, the largest is mapped first. For equal size, the first
4529 bank (CS2#) is mapped first. The first mapping is always for address
4530 0x00000000, with any additional banks following immediately to create
4531 contiguous memory starting from 0.
4533 Then, the monitor installs itself at the upper end of the SDRAM area
4534 and allocates memory for use by malloc() and for the global Board
4535 Info data; also, the exception vector code is copied to the low RAM
4536 pages, and the final stack is set up.
4538 Only after this relocation will you have a "normal" C environment;
4539 until that you are restricted in several ways, mostly because you are
4540 running from ROM, and because the code will have to be relocated to a
4544 U-Boot Porting Guide:
4545 ----------------------
4547 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4551 int main(int argc, char *argv[])
4553 sighandler_t no_more_time;
4555 signal(SIGALRM, no_more_time);
4556 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4558 if (available_money > available_manpower) {
4559 Pay consultant to port U-Boot;
4563 Download latest U-Boot source;
4565 Subscribe to u-boot mailing list;
4568 email("Hi, I am new to U-Boot, how do I get started?");
4571 Read the README file in the top level directory;
4572 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4573 Read applicable doc/*.README;
4574 Read the source, Luke;
4575 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4578 if (available_money > toLocalCurrency ($2500))
4581 Add a lot of aggravation and time;
4583 if (a similar board exists) { /* hopefully... */
4584 cp -a board/<similar> board/<myboard>
4585 cp include/configs/<similar>.h include/configs/<myboard>.h
4587 Create your own board support subdirectory;
4588 Create your own board include/configs/<myboard>.h file;
4590 Edit new board/<myboard> files
4591 Edit new include/configs/<myboard>.h
4596 Add / modify source code;
4600 email("Hi, I am having problems...");
4602 Send patch file to the U-Boot email list;
4603 if (reasonable critiques)
4604 Incorporate improvements from email list code review;
4606 Defend code as written;
4612 void no_more_time (int sig)
4621 All contributions to U-Boot should conform to the Linux kernel
4622 coding style; see the file "Documentation/CodingStyle" and the script
4623 "scripts/Lindent" in your Linux kernel source directory.
4625 Source files originating from a different project (for example the
4626 MTD subsystem) are generally exempt from these guidelines and are not
4627 reformated to ease subsequent migration to newer versions of those
4630 Please note that U-Boot is implemented in C (and to some small parts in
4631 Assembler); no C++ is used, so please do not use C++ style comments (//)
4634 Please also stick to the following formatting rules:
4635 - remove any trailing white space
4636 - use TAB characters for indentation and vertical alignment, not spaces
4637 - make sure NOT to use DOS '\r\n' line feeds
4638 - do not add more than 2 consecutive empty lines to source files
4639 - do not add trailing empty lines to source files
4641 Submissions which do not conform to the standards may be returned
4642 with a request to reformat the changes.
4648 Since the number of patches for U-Boot is growing, we need to
4649 establish some rules. Submissions which do not conform to these rules
4650 may be rejected, even when they contain important and valuable stuff.
4652 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4654 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4655 see http://lists.denx.de/mailman/listinfo/u-boot
4657 When you send a patch, please include the following information with
4660 * For bug fixes: a description of the bug and how your patch fixes
4661 this bug. Please try to include a way of demonstrating that the
4662 patch actually fixes something.
4664 * For new features: a description of the feature and your
4667 * A CHANGELOG entry as plaintext (separate from the patch)
4669 * For major contributions, your entry to the CREDITS file
4671 * When you add support for a new board, don't forget to add this
4672 board to the MAINTAINERS file, too.
4674 * If your patch adds new configuration options, don't forget to
4675 document these in the README file.
4677 * The patch itself. If you are using git (which is *strongly*
4678 recommended) you can easily generate the patch using the
4679 "git format-patch". If you then use "git send-email" to send it to
4680 the U-Boot mailing list, you will avoid most of the common problems
4681 with some other mail clients.
4683 If you cannot use git, use "diff -purN OLD NEW". If your version of
4684 diff does not support these options, then get the latest version of
4687 The current directory when running this command shall be the parent
4688 directory of the U-Boot source tree (i. e. please make sure that
4689 your patch includes sufficient directory information for the
4692 We prefer patches as plain text. MIME attachments are discouraged,
4693 and compressed attachments must not be used.
4695 * If one logical set of modifications affects or creates several
4696 files, all these changes shall be submitted in a SINGLE patch file.
4698 * Changesets that contain different, unrelated modifications shall be
4699 submitted as SEPARATE patches, one patch per changeset.
4704 * Before sending the patch, run the MAKEALL script on your patched
4705 source tree and make sure that no errors or warnings are reported
4706 for any of the boards.
4708 * Keep your modifications to the necessary minimum: A patch
4709 containing several unrelated changes or arbitrary reformats will be
4710 returned with a request to re-formatting / split it.
4712 * If you modify existing code, make sure that your new code does not
4713 add to the memory footprint of the code ;-) Small is beautiful!
4714 When adding new features, these should compile conditionally only
4715 (using #ifdef), and the resulting code with the new feature
4716 disabled must not need more memory than the old code without your
4719 * Remember that there is a size limit of 100 kB per message on the
4720 u-boot mailing list. Bigger patches will be moderated. If they are
4721 reasonable and not too big, they will be acknowledged. But patches
4722 bigger than the size limit should be avoided.
projects / karo-tx-uboot.git / blob