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1 #
2 # (C) Copyright 2000 - 2008
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 #
5 # See file CREDITS for list of people who contributed to this
6 # project.
7 #
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.
12 #
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.
17 #
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,
21 # MA 02111-1307 USA
22 #
24 Summary:
25 ========
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
31 code.
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.
46 Status:
47 =======
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
55 maintainers.
58 Where to get help:
59 ==================
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-users@lists.sourceforge.net>. There is also an archive of
64 previous traffic on the mailing list - please search the archive
65 before asking FAQ's. Please see
66 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
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. Ofifcial releases are also
78 available for FTP download from the ftp://ftp.denx.de/pub/u-boot/
79 directory.
81 Pre-built (and tested) images are available from
82 ftp://ftp.denx.de/pub/u-boot/images/
85 Where we come from:
86 ===================
88 - start from 8xxrom sources
89 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
90 - clean up code
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
95 * S-Record download
96 * network boot
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/UBoot
104 Names and Spelling:
105 ===================
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
126 Versioning:
127 ===========
129 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
138 Directory Hierarchy:
139 ====================
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - i386 Files specific to i386 CPUs
155 - ixp Files specific to Intel XScale IXP CPUs
156 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
157 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
158 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
159 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
160 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
161 - mips Files specific to MIPS CPUs
162 - mpc5xx Files specific to Freescale MPC5xx CPUs
163 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
164 - mpc8xx Files specific to Freescale MPC8xx CPUs
165 - mpc8220 Files specific to Freescale MPC8220 CPUs
166 - mpc824x Files specific to Freescale MPC824x CPUs
167 - mpc8260 Files specific to Freescale MPC8260 CPUs
168 - mpc85xx Files specific to Freescale MPC85xx CPUs
169 - nios Files specific to Altera NIOS CPUs
170 - nios2 Files specific to Altera Nios-II CPUs
171 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
172 - pxa Files specific to Intel XScale PXA CPUs
173 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
174 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
175 - disk Code for disk drive partition handling
176 - doc Documentation (don't expect too much)
177 - drivers Commonly used device drivers
178 - dtt Digital Thermometer and Thermostat drivers
179 - examples Example code for standalone applications, etc.
180 - include Header Files
181 - lib_arm Files generic to ARM architecture
182 - lib_avr32 Files generic to AVR32 architecture
183 - lib_generic Files generic to all architectures
184 - lib_i386 Files generic to i386 architecture
185 - lib_m68k Files generic to m68k architecture
186 - lib_mips Files generic to MIPS architecture
187 - lib_nios Files generic to NIOS architecture
188 - lib_ppc Files generic to PowerPC architecture
189 - libfdt Library files to support flattened device trees
190 - net Networking code
191 - post Power On Self Test
192 - rtc Real Time Clock drivers
193 - tools Tools to build S-Record or U-Boot images, etc.
195 Software Configuration:
196 =======================
198 Configuration is usually done using C preprocessor defines; the
199 rationale behind that is to avoid dead code whenever possible.
201 There are two classes of configuration variables:
203 * Configuration _OPTIONS_:
204 These are selectable by the user and have names beginning with
205 "CONFIG_".
207 * Configuration _SETTINGS_:
208 These depend on the hardware etc. and should not be meddled with if
209 you don't know what you're doing; they have names beginning with
210 "CFG_".
212 Later we will add a configuration tool - probably similar to or even
213 identical to what's used for the Linux kernel. Right now, we have to
214 do the configuration by hand, which means creating some symbolic
215 links and editing some configuration files. We use the TQM8xxL boards
216 as an example here.
219 Selection of Processor Architecture and Board Type:
220 ---------------------------------------------------
222 For all supported boards there are ready-to-use default
223 configurations available; just type "make <board_name>_config".
225 Example: For a TQM823L module type:
227 cd u-boot
228 make TQM823L_config
230 For the Cogent platform, you need to specify the cpu type as well;
231 e.g. "make cogent_mpc8xx_config". And also configure the cogent
232 directory according to the instructions in cogent/README.
235 Configuration Options:
236 ----------------------
238 Configuration depends on the combination of board and CPU type; all
239 such information is kept in a configuration file
240 "include/configs/<board_name>.h".
242 Example: For a TQM823L module, all configuration settings are in
243 "include/configs/TQM823L.h".
246 Many of the options are named exactly as the corresponding Linux
247 kernel configuration options. The intention is to make it easier to
248 build a config tool - later.
251 The following options need to be configured:
253 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
255 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
257 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
258 Define exactly one, e.g. CONFIG_ATSTK1002
260 - CPU Module Type: (if CONFIG_COGENT is defined)
261 Define exactly one of
262 CONFIG_CMA286_60_OLD
263 --- FIXME --- not tested yet:
264 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
265 CONFIG_CMA287_23, CONFIG_CMA287_50
267 - Motherboard Type: (if CONFIG_COGENT is defined)
268 Define exactly one of
269 CONFIG_CMA101, CONFIG_CMA102
271 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
272 Define one or more of
273 CONFIG_CMA302
275 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
276 Define one or more of
277 CONFIG_LCD_HEARTBEAT - update a character position on
278 the lcd display every second with
279 a "rotator" |\-/|\-/
281 - Board flavour: (if CONFIG_MPC8260ADS is defined)
282 CONFIG_ADSTYPE
283 Possible values are:
284 CFG_8260ADS - original MPC8260ADS
285 CFG_8266ADS - MPC8266ADS
286 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
287 CFG_8272ADS - MPC8272ADS
289 - MPC824X Family Member (if CONFIG_MPC824X is defined)
290 Define exactly one of
291 CONFIG_MPC8240, CONFIG_MPC8245
293 - 8xx CPU Options: (if using an MPC8xx cpu)
294 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
295 get_gclk_freq() cannot work
296 e.g. if there is no 32KHz
297 reference PIT/RTC clock
298 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
299 or XTAL/EXTAL)
301 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
302 CFG_8xx_CPUCLK_MIN
303 CFG_8xx_CPUCLK_MAX
304 CONFIG_8xx_CPUCLK_DEFAULT
305 See doc/README.MPC866
307 CFG_MEASURE_CPUCLK
309 Define this to measure the actual CPU clock instead
310 of relying on the correctness of the configured
311 values. Mostly useful for board bringup to make sure
312 the PLL is locked at the intended frequency. Note
313 that this requires a (stable) reference clock (32 kHz
314 RTC clock or CFG_8XX_XIN)
316 - Intel Monahans options:
317 CFG_MONAHANS_RUN_MODE_OSC_RATIO
319 Defines the Monahans run mode to oscillator
320 ratio. Valid values are 8, 16, 24, 31. The core
321 frequency is this value multiplied by 13 MHz.
323 CFG_MONAHANS_TURBO_RUN_MODE_RATIO
325 Defines the Monahans turbo mode to oscillator
326 ratio. Valid values are 1 (default if undefined) and
327 2. The core frequency as calculated above is multiplied
328 by this value.
330 - Linux Kernel Interface:
331 CONFIG_CLOCKS_IN_MHZ
333 U-Boot stores all clock information in Hz
334 internally. For binary compatibility with older Linux
335 kernels (which expect the clocks passed in the
336 bd_info data to be in MHz) the environment variable
337 "clocks_in_mhz" can be defined so that U-Boot
338 converts clock data to MHZ before passing it to the
339 Linux kernel.
340 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
341 "clocks_in_mhz=1" is automatically included in the
342 default environment.
344 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
346 When transfering memsize parameter to linux, some versions
347 expect it to be in bytes, others in MB.
348 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
350 CONFIG_OF_LIBFDT / CONFIG_OF_FLAT_TREE
352 New kernel versions are expecting firmware settings to be
353 passed using flattened device trees (based on open firmware
354 concepts).
356 CONFIG_OF_LIBFDT
357 * New libfdt-based support
358 * Adds the "fdt" command
359 * The bootm command automatically updates the fdt
361 CONFIG_OF_FLAT_TREE
362 * Deprecated, see CONFIG_OF_LIBFDT
363 * Original ft_build.c-based support
364 * Automatically modifies the dft as part of the bootm command
365 * The environment variable "disable_of", when set,
366 disables this functionality.
368 OF_CPU - The proper name of the cpus node.
369 OF_SOC - The proper name of the soc node.
370 OF_TBCLK - The timebase frequency.
371 OF_STDOUT_PATH - The path to the console device
373 boards with QUICC Engines require OF_QE to set UCC mac addresses
375 CONFIG_OF_BOARD_SETUP
377 Board code has addition modification that it wants to make
378 to the flat device tree before handing it off to the kernel
380 CONFIG_OF_BOOT_CPU
382 This define fills in the correct boot cpu in the boot
383 param header, the default value is zero if undefined.
385 - Serial Ports:
386 CFG_PL010_SERIAL
388 Define this if you want support for Amba PrimeCell PL010 UARTs.
390 CFG_PL011_SERIAL
392 Define this if you want support for Amba PrimeCell PL011 UARTs.
394 CONFIG_PL011_CLOCK
396 If you have Amba PrimeCell PL011 UARTs, set this variable to
397 the clock speed of the UARTs.
399 CONFIG_PL01x_PORTS
401 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
402 define this to a list of base addresses for each (supported)
403 port. See e.g. include/configs/versatile.h
406 - Console Interface:
407 Depending on board, define exactly one serial port
408 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
409 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
410 console by defining CONFIG_8xx_CONS_NONE
412 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
413 port routines must be defined elsewhere
414 (i.e. serial_init(), serial_getc(), ...)
416 CONFIG_CFB_CONSOLE
417 Enables console device for a color framebuffer. Needs following
418 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
419 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
420 (default big endian)
421 VIDEO_HW_RECTFILL graphic chip supports
422 rectangle fill
423 (cf. smiLynxEM)
424 VIDEO_HW_BITBLT graphic chip supports
425 bit-blit (cf. smiLynxEM)
426 VIDEO_VISIBLE_COLS visible pixel columns
427 (cols=pitch)
428 VIDEO_VISIBLE_ROWS visible pixel rows
429 VIDEO_PIXEL_SIZE bytes per pixel
430 VIDEO_DATA_FORMAT graphic data format
431 (0-5, cf. cfb_console.c)
432 VIDEO_FB_ADRS framebuffer address
433 VIDEO_KBD_INIT_FCT keyboard int fct
434 (i.e. i8042_kbd_init())
435 VIDEO_TSTC_FCT test char fct
436 (i.e. i8042_tstc)
437 VIDEO_GETC_FCT get char fct
438 (i.e. i8042_getc)
439 CONFIG_CONSOLE_CURSOR cursor drawing on/off
440 (requires blink timer
441 cf. i8042.c)
442 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
443 CONFIG_CONSOLE_TIME display time/date info in
444 upper right corner
445 (requires CONFIG_CMD_DATE)
446 CONFIG_VIDEO_LOGO display Linux logo in
447 upper left corner
448 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
449 linux_logo.h for logo.
450 Requires CONFIG_VIDEO_LOGO
451 CONFIG_CONSOLE_EXTRA_INFO
452 addional board info beside
453 the logo
455 When CONFIG_CFB_CONSOLE is defined, video console is
456 default i/o. Serial console can be forced with
457 environment 'console=serial'.
459 When CONFIG_SILENT_CONSOLE is defined, all console
460 messages (by U-Boot and Linux!) can be silenced with
461 the "silent" environment variable. See
462 doc/README.silent for more information.
464 - Console Baudrate:
465 CONFIG_BAUDRATE - in bps
466 Select one of the baudrates listed in
467 CFG_BAUDRATE_TABLE, see below.
468 CFG_BRGCLK_PRESCALE, baudrate prescale
470 - Interrupt driven serial port input:
471 CONFIG_SERIAL_SOFTWARE_FIFO
473 PPC405GP only.
474 Use an interrupt handler for receiving data on the
475 serial port. It also enables using hardware handshake
476 (RTS/CTS) and UART's built-in FIFO. Set the number of
477 bytes the interrupt driven input buffer should have.
479 Leave undefined to disable this feature, including
480 disable the buffer and hardware handshake.
482 - Console UART Number:
483 CONFIG_UART1_CONSOLE
485 AMCC PPC4xx only.
486 If defined internal UART1 (and not UART0) is used
487 as default U-Boot console.
489 - Boot Delay: CONFIG_BOOTDELAY - in seconds
490 Delay before automatically booting the default image;
491 set to -1 to disable autoboot.
493 See doc/README.autoboot for these options that
494 work with CONFIG_BOOTDELAY. None are required.
495 CONFIG_BOOT_RETRY_TIME
496 CONFIG_BOOT_RETRY_MIN
497 CONFIG_AUTOBOOT_KEYED
498 CONFIG_AUTOBOOT_PROMPT
499 CONFIG_AUTOBOOT_DELAY_STR
500 CONFIG_AUTOBOOT_STOP_STR
501 CONFIG_AUTOBOOT_DELAY_STR2
502 CONFIG_AUTOBOOT_STOP_STR2
503 CONFIG_ZERO_BOOTDELAY_CHECK
504 CONFIG_RESET_TO_RETRY
506 - Autoboot Command:
507 CONFIG_BOOTCOMMAND
508 Only needed when CONFIG_BOOTDELAY is enabled;
509 define a command string that is automatically executed
510 when no character is read on the console interface
511 within "Boot Delay" after reset.
513 CONFIG_BOOTARGS
514 This can be used to pass arguments to the bootm
515 command. The value of CONFIG_BOOTARGS goes into the
516 environment value "bootargs".
518 CONFIG_RAMBOOT and CONFIG_NFSBOOT
519 The value of these goes into the environment as
520 "ramboot" and "nfsboot" respectively, and can be used
521 as a convenience, when switching between booting from
522 ram and nfs.
524 - Pre-Boot Commands:
525 CONFIG_PREBOOT
527 When this option is #defined, the existence of the
528 environment variable "preboot" will be checked
529 immediately before starting the CONFIG_BOOTDELAY
530 countdown and/or running the auto-boot command resp.
531 entering interactive mode.
533 This feature is especially useful when "preboot" is
534 automatically generated or modified. For an example
535 see the LWMON board specific code: here "preboot" is
536 modified when the user holds down a certain
537 combination of keys on the (special) keyboard when
538 booting the systems
540 - Serial Download Echo Mode:
541 CONFIG_LOADS_ECHO
542 If defined to 1, all characters received during a
543 serial download (using the "loads" command) are
544 echoed back. This might be needed by some terminal
545 emulations (like "cu"), but may as well just take
546 time on others. This setting #define's the initial
547 value of the "loads_echo" environment variable.
549 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
550 CONFIG_KGDB_BAUDRATE
551 Select one of the baudrates listed in
552 CFG_BAUDRATE_TABLE, see below.
554 - Monitor Functions:
555 Monitor commands can be included or excluded
556 from the build by using the #include files
557 "config_cmd_all.h" and #undef'ing unwanted
558 commands, or using "config_cmd_default.h"
559 and augmenting with additional #define's
560 for wanted commands.
562 The default command configuration includes all commands
563 except those marked below with a "*".
565 CONFIG_CMD_ASKENV * ask for env variable
566 CONFIG_CMD_AUTOSCRIPT Autoscript Support
567 CONFIG_CMD_BDI bdinfo
568 CONFIG_CMD_BEDBUG * Include BedBug Debugger
569 CONFIG_CMD_BMP * BMP support
570 CONFIG_CMD_BSP * Board specific commands
571 CONFIG_CMD_BOOTD bootd
572 CONFIG_CMD_CACHE * icache, dcache
573 CONFIG_CMD_CONSOLE coninfo
574 CONFIG_CMD_DATE * support for RTC, date/time...
575 CONFIG_CMD_DHCP * DHCP support
576 CONFIG_CMD_DIAG * Diagnostics
577 CONFIG_CMD_DOC * Disk-On-Chip Support
578 CONFIG_CMD_DTT * Digital Therm and Thermostat
579 CONFIG_CMD_ECHO echo arguments
580 CONFIG_CMD_EEPROM * EEPROM read/write support
581 CONFIG_CMD_ELF * bootelf, bootvx
582 CONFIG_CMD_ENV saveenv
583 CONFIG_CMD_FDC * Floppy Disk Support
584 CONFIG_CMD_FAT * FAT partition support
585 CONFIG_CMD_FDOS * Dos diskette Support
586 CONFIG_CMD_FLASH flinfo, erase, protect
587 CONFIG_CMD_FPGA FPGA device initialization support
588 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
589 CONFIG_CMD_I2C * I2C serial bus support
590 CONFIG_CMD_IDE * IDE harddisk support
591 CONFIG_CMD_IMI iminfo
592 CONFIG_CMD_IMLS List all found images
593 CONFIG_CMD_IMMAP * IMMR dump support
594 CONFIG_CMD_IRQ * irqinfo
595 CONFIG_CMD_ITEST Integer/string test of 2 values
596 CONFIG_CMD_JFFS2 * JFFS2 Support
597 CONFIG_CMD_KGDB * kgdb
598 CONFIG_CMD_LOADB loadb
599 CONFIG_CMD_LOADS loads
600 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
601 loop, loopw, mtest
602 CONFIG_CMD_MISC Misc functions like sleep etc
603 CONFIG_CMD_MMC * MMC memory mapped support
604 CONFIG_CMD_MII * MII utility commands
605 CONFIG_CMD_NAND * NAND support
606 CONFIG_CMD_NET bootp, tftpboot, rarpboot
607 CONFIG_CMD_PCI * pciinfo
608 CONFIG_CMD_PCMCIA * PCMCIA support
609 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
610 host
611 CONFIG_CMD_PORTIO * Port I/O
612 CONFIG_CMD_REGINFO * Register dump
613 CONFIG_CMD_RUN run command in env variable
614 CONFIG_CMD_SAVES * save S record dump
615 CONFIG_CMD_SCSI * SCSI Support
616 CONFIG_CMD_SDRAM * print SDRAM configuration information
617 (requires CONFIG_CMD_I2C)
618 CONFIG_CMD_SETGETDCR Support for DCR Register access
619 (4xx only)
620 CONFIG_CMD_SPI * SPI serial bus support
621 CONFIG_CMD_USB * USB support
622 CONFIG_CMD_VFD * VFD support (TRAB)
623 CONFIG_CMD_BSP * Board SPecific functions
624 CONFIG_CMD_CDP * Cisco Discover Protocol support
625 CONFIG_CMD_FSL * Microblaze FSL support
628 EXAMPLE: If you want all functions except of network
629 support you can write:
631 #include "config_cmd_all.h"
632 #undef CONFIG_CMD_NET
634 Other Commands:
635 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
637 Note: Don't enable the "icache" and "dcache" commands
638 (configuration option CONFIG_CMD_CACHE) unless you know
639 what you (and your U-Boot users) are doing. Data
640 cache cannot be enabled on systems like the 8xx or
641 8260 (where accesses to the IMMR region must be
642 uncached), and it cannot be disabled on all other
643 systems where we (mis-) use the data cache to hold an
644 initial stack and some data.
647 XXX - this list needs to get updated!
649 - Watchdog:
650 CONFIG_WATCHDOG
651 If this variable is defined, it enables watchdog
652 support. There must be support in the platform specific
653 code for a watchdog. For the 8xx and 8260 CPUs, the
654 SIU Watchdog feature is enabled in the SYPCR
655 register.
657 - U-Boot Version:
658 CONFIG_VERSION_VARIABLE
659 If this variable is defined, an environment variable
660 named "ver" is created by U-Boot showing the U-Boot
661 version as printed by the "version" command.
662 This variable is readonly.
664 - Real-Time Clock:
666 When CONFIG_CMD_DATE is selected, the type of the RTC
667 has to be selected, too. Define exactly one of the
668 following options:
670 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
671 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
672 CONFIG_RTC_MC146818 - use MC146818 RTC
673 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
674 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
675 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
676 CONFIG_RTC_DS164x - use Dallas DS164x RTC
677 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
678 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
679 CFG_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
681 Note that if the RTC uses I2C, then the I2C interface
682 must also be configured. See I2C Support, below.
684 - Timestamp Support:
686 When CONFIG_TIMESTAMP is selected, the timestamp
687 (date and time) of an image is printed by image
688 commands like bootm or iminfo. This option is
689 automatically enabled when you select CONFIG_CMD_DATE .
691 - Partition Support:
692 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
693 and/or CONFIG_ISO_PARTITION
695 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
696 CONFIG_CMD_SCSI) you must configure support for at
697 least one partition type as well.
699 - IDE Reset method:
700 CONFIG_IDE_RESET_ROUTINE - this is defined in several
701 board configurations files but used nowhere!
703 CONFIG_IDE_RESET - is this is defined, IDE Reset will
704 be performed by calling the function
705 ide_set_reset(int reset)
706 which has to be defined in a board specific file
708 - ATAPI Support:
709 CONFIG_ATAPI
711 Set this to enable ATAPI support.
713 - LBA48 Support
714 CONFIG_LBA48
716 Set this to enable support for disks larger than 137GB
717 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
718 Whithout these , LBA48 support uses 32bit variables and will 'only'
719 support disks up to 2.1TB.
721 CFG_64BIT_LBA:
722 When enabled, makes the IDE subsystem use 64bit sector addresses.
723 Default is 32bit.
725 - SCSI Support:
726 At the moment only there is only support for the
727 SYM53C8XX SCSI controller; define
728 CONFIG_SCSI_SYM53C8XX to enable it.
730 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
731 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
732 CFG_SCSI_MAX_LUN] can be adjusted to define the
733 maximum numbers of LUNs, SCSI ID's and target
734 devices.
735 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
737 - NETWORK Support (PCI):
738 CONFIG_E1000
739 Support for Intel 8254x gigabit chips.
741 CONFIG_E1000_FALLBACK_MAC
742 default MAC for empty eeprom after production.
744 CONFIG_EEPRO100
745 Support for Intel 82557/82559/82559ER chips.
746 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
747 write routine for first time initialisation.
749 CONFIG_TULIP
750 Support for Digital 2114x chips.
751 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
752 modem chip initialisation (KS8761/QS6611).
754 CONFIG_NATSEMI
755 Support for National dp83815 chips.
757 CONFIG_NS8382X
758 Support for National dp8382[01] gigabit chips.
760 - NETWORK Support (other):
762 CONFIG_DRIVER_LAN91C96
763 Support for SMSC's LAN91C96 chips.
765 CONFIG_LAN91C96_BASE
766 Define this to hold the physical address
767 of the LAN91C96's I/O space
769 CONFIG_LAN91C96_USE_32_BIT
770 Define this to enable 32 bit addressing
772 CONFIG_DRIVER_SMC91111
773 Support for SMSC's LAN91C111 chip
775 CONFIG_SMC91111_BASE
776 Define this to hold the physical address
777 of the device (I/O space)
779 CONFIG_SMC_USE_32_BIT
780 Define this if data bus is 32 bits
782 CONFIG_SMC_USE_IOFUNCS
783 Define this to use i/o functions instead of macros
784 (some hardware wont work with macros)
786 - USB Support:
787 At the moment only the UHCI host controller is
788 supported (PIP405, MIP405, MPC5200); define
789 CONFIG_USB_UHCI to enable it.
790 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
791 and define CONFIG_USB_STORAGE to enable the USB
792 storage devices.
793 Note:
794 Supported are USB Keyboards and USB Floppy drives
795 (TEAC FD-05PUB).
796 MPC5200 USB requires additional defines:
797 CONFIG_USB_CLOCK
798 for 528 MHz Clock: 0x0001bbbb
799 CONFIG_USB_CONFIG
800 for differential drivers: 0x00001000
801 for single ended drivers: 0x00005000
802 CFG_USB_EVENT_POLL
803 May be defined to allow interrupt polling
804 instead of using asynchronous interrupts
806 - USB Device:
807 Define the below if you wish to use the USB console.
808 Once firmware is rebuilt from a serial console issue the
809 command "setenv stdin usbtty; setenv stdout usbtty" and
810 attach your usb cable. The Unix command "dmesg" should print
811 it has found a new device. The environment variable usbtty
812 can be set to gserial or cdc_acm to enable your device to
813 appear to a USB host as a Linux gserial device or a
814 Common Device Class Abstract Control Model serial device.
815 If you select usbtty = gserial you should be able to enumerate
816 a Linux host by
817 # modprobe usbserial vendor=0xVendorID product=0xProductID
818 else if using cdc_acm, simply setting the environment
819 variable usbtty to be cdc_acm should suffice. The following
820 might be defined in YourBoardName.h
822 CONFIG_USB_DEVICE
823 Define this to build a UDC device
825 CONFIG_USB_TTY
826 Define this to have a tty type of device available to
827 talk to the UDC device
829 CFG_CONSOLE_IS_IN_ENV
830 Define this if you want stdin, stdout &/or stderr to
831 be set to usbtty.
833 mpc8xx:
834 CFG_USB_EXTC_CLK 0xBLAH
835 Derive USB clock from external clock "blah"
836 - CFG_USB_EXTC_CLK 0x02
838 CFG_USB_BRG_CLK 0xBLAH
839 Derive USB clock from brgclk
840 - CFG_USB_BRG_CLK 0x04
842 If you have a USB-IF assigned VendorID then you may wish to
843 define your own vendor specific values either in BoardName.h
844 or directly in usbd_vendor_info.h. If you don't define
845 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
846 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
847 should pretend to be a Linux device to it's target host.
849 CONFIG_USBD_MANUFACTURER
850 Define this string as the name of your company for
851 - CONFIG_USBD_MANUFACTURER "my company"
853 CONFIG_USBD_PRODUCT_NAME
854 Define this string as the name of your product
855 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
857 CONFIG_USBD_VENDORID
858 Define this as your assigned Vendor ID from the USB
859 Implementors Forum. This *must* be a genuine Vendor ID
860 to avoid polluting the USB namespace.
861 - CONFIG_USBD_VENDORID 0xFFFF
863 CONFIG_USBD_PRODUCTID
864 Define this as the unique Product ID
865 for your device
866 - CONFIG_USBD_PRODUCTID 0xFFFF
869 - MMC Support:
870 The MMC controller on the Intel PXA is supported. To
871 enable this define CONFIG_MMC. The MMC can be
872 accessed from the boot prompt by mapping the device
873 to physical memory similar to flash. Command line is
874 enabled with CONFIG_CMD_MMC. The MMC driver also works with
875 the FAT fs. This is enabled with CONFIG_CMD_FAT.
877 - Journaling Flash filesystem support:
878 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
879 CONFIG_JFFS2_NAND_DEV
880 Define these for a default partition on a NAND device
882 CFG_JFFS2_FIRST_SECTOR,
883 CFG_JFFS2_FIRST_BANK, CFG_JFFS2_NUM_BANKS
884 Define these for a default partition on a NOR device
886 CFG_JFFS_CUSTOM_PART
887 Define this to create an own partition. You have to provide a
888 function struct part_info* jffs2_part_info(int part_num)
890 If you define only one JFFS2 partition you may also want to
891 #define CFG_JFFS_SINGLE_PART 1
892 to disable the command chpart. This is the default when you
893 have not defined a custom partition
895 - Keyboard Support:
896 CONFIG_ISA_KEYBOARD
898 Define this to enable standard (PC-Style) keyboard
899 support
901 CONFIG_I8042_KBD
902 Standard PC keyboard driver with US (is default) and
903 GERMAN key layout (switch via environment 'keymap=de') support.
904 Export function i8042_kbd_init, i8042_tstc and i8042_getc
905 for cfb_console. Supports cursor blinking.
907 - Video support:
908 CONFIG_VIDEO
910 Define this to enable video support (for output to
911 video).
913 CONFIG_VIDEO_CT69000
915 Enable Chips & Technologies 69000 Video chip
917 CONFIG_VIDEO_SMI_LYNXEM
918 Enable Silicon Motion SMI 712/710/810 Video chip. The
919 video output is selected via environment 'videoout'
920 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
921 assumed.
923 For the CT69000 and SMI_LYNXEM drivers, videomode is
924 selected via environment 'videomode'. Two diferent ways
925 are possible:
926 - "videomode=num" 'num' is a standard LiLo mode numbers.
927 Following standard modes are supported (* is default):
929 Colors 640x480 800x600 1024x768 1152x864 1280x1024
930 -------------+---------------------------------------------
931 8 bits | 0x301* 0x303 0x305 0x161 0x307
932 15 bits | 0x310 0x313 0x316 0x162 0x319
933 16 bits | 0x311 0x314 0x317 0x163 0x31A
934 24 bits | 0x312 0x315 0x318 ? 0x31B
935 -------------+---------------------------------------------
936 (i.e. setenv videomode 317; saveenv; reset;)
938 - "videomode=bootargs" all the video parameters are parsed
939 from the bootargs. (See drivers/video/videomodes.c)
942 CONFIG_VIDEO_SED13806
943 Enable Epson SED13806 driver. This driver supports 8bpp
944 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
945 or CONFIG_VIDEO_SED13806_16BPP
947 - Keyboard Support:
948 CONFIG_KEYBOARD
950 Define this to enable a custom keyboard support.
951 This simply calls drv_keyboard_init() which must be
952 defined in your board-specific files.
953 The only board using this so far is RBC823.
955 - LCD Support: CONFIG_LCD
957 Define this to enable LCD support (for output to LCD
958 display); also select one of the supported displays
959 by defining one of these:
961 CONFIG_NEC_NL6448AC33:
963 NEC NL6448AC33-18. Active, color, single scan.
965 CONFIG_NEC_NL6448BC20
967 NEC NL6448BC20-08. 6.5", 640x480.
968 Active, color, single scan.
970 CONFIG_NEC_NL6448BC33_54
972 NEC NL6448BC33-54. 10.4", 640x480.
973 Active, color, single scan.
975 CONFIG_SHARP_16x9
977 Sharp 320x240. Active, color, single scan.
978 It isn't 16x9, and I am not sure what it is.
980 CONFIG_SHARP_LQ64D341
982 Sharp LQ64D341 display, 640x480.
983 Active, color, single scan.
985 CONFIG_HLD1045
987 HLD1045 display, 640x480.
988 Active, color, single scan.
990 CONFIG_OPTREX_BW
992 Optrex CBL50840-2 NF-FW 99 22 M5
993 or
994 Hitachi LMG6912RPFC-00T
995 or
996 Hitachi SP14Q002
998 320x240. Black & white.
1000 Normally display is black on white background; define
1001 CFG_WHITE_ON_BLACK to get it inverted.
1003 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1005 If this option is set, the environment is checked for
1006 a variable "splashimage". If found, the usual display
1007 of logo, copyright and system information on the LCD
1008 is suppressed and the BMP image at the address
1009 specified in "splashimage" is loaded instead. The
1010 console is redirected to the "nulldev", too. This
1011 allows for a "silent" boot where a splash screen is
1012 loaded very quickly after power-on.
1014 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1016 If this option is set, additionally to standard BMP
1017 images, gzipped BMP images can be displayed via the
1018 splashscreen support or the bmp command.
1020 - Compression support:
1021 CONFIG_BZIP2
1023 If this option is set, support for bzip2 compressed
1024 images is included. If not, only uncompressed and gzip
1025 compressed images are supported.
1027 NOTE: the bzip2 algorithm requires a lot of RAM, so
1028 the malloc area (as defined by CFG_MALLOC_LEN) should
1029 be at least 4MB.
1031 - MII/PHY support:
1032 CONFIG_PHY_ADDR
1034 The address of PHY on MII bus.
1036 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1038 The clock frequency of the MII bus
1040 CONFIG_PHY_GIGE
1042 If this option is set, support for speed/duplex
1043 detection of Gigabit PHY is included.
1045 CONFIG_PHY_RESET_DELAY
1047 Some PHY like Intel LXT971A need extra delay after
1048 reset before any MII register access is possible.
1049 For such PHY, set this option to the usec delay
1050 required. (minimum 300usec for LXT971A)
1052 CONFIG_PHY_CMD_DELAY (ppc4xx)
1054 Some PHY like Intel LXT971A need extra delay after
1055 command issued before MII status register can be read
1057 - Ethernet address:
1058 CONFIG_ETHADDR
1059 CONFIG_ETH2ADDR
1060 CONFIG_ETH3ADDR
1062 Define a default value for ethernet address to use
1063 for the respective ethernet interface, in case this
1064 is not determined automatically.
1066 - IP address:
1067 CONFIG_IPADDR
1069 Define a default value for the IP address to use for
1070 the default ethernet interface, in case this is not
1071 determined through e.g. bootp.
1073 - Server IP address:
1074 CONFIG_SERVERIP
1076 Defines a default value for theIP address of a TFTP
1077 server to contact when using the "tftboot" command.
1079 - Multicast TFTP Mode:
1080 CONFIG_MCAST_TFTP
1082 Defines whether you want to support multicast TFTP as per
1083 rfc-2090; for example to work with atftp. Lets lots of targets
1084 tftp down the same boot image concurrently. Note: the ethernet
1085 driver in use must provide a function: mcast() to join/leave a
1086 multicast group.
1088 CONFIG_BOOTP_RANDOM_DELAY
1089 - BOOTP Recovery Mode:
1090 CONFIG_BOOTP_RANDOM_DELAY
1092 If you have many targets in a network that try to
1093 boot using BOOTP, you may want to avoid that all
1094 systems send out BOOTP requests at precisely the same
1095 moment (which would happen for instance at recovery
1096 from a power failure, when all systems will try to
1097 boot, thus flooding the BOOTP server. Defining
1098 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1099 inserted before sending out BOOTP requests. The
1100 following delays are inserted then:
1102 1st BOOTP request: delay 0 ... 1 sec
1103 2nd BOOTP request: delay 0 ... 2 sec
1104 3rd BOOTP request: delay 0 ... 4 sec
1105 4th and following
1106 BOOTP requests: delay 0 ... 8 sec
1108 - DHCP Advanced Options:
1109 You can fine tune the DHCP functionality by defining
1110 CONFIG_BOOTP_* symbols:
1112 CONFIG_BOOTP_SUBNETMASK
1113 CONFIG_BOOTP_GATEWAY
1114 CONFIG_BOOTP_HOSTNAME
1115 CONFIG_BOOTP_NISDOMAIN
1116 CONFIG_BOOTP_BOOTPATH
1117 CONFIG_BOOTP_BOOTFILESIZE
1118 CONFIG_BOOTP_DNS
1119 CONFIG_BOOTP_DNS2
1120 CONFIG_BOOTP_SEND_HOSTNAME
1121 CONFIG_BOOTP_NTPSERVER
1122 CONFIG_BOOTP_TIMEOFFSET
1123 CONFIG_BOOTP_VENDOREX
1125 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1126 environment variable, not the BOOTP server.
1128 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1129 serverip from a DHCP server, it is possible that more
1130 than one DNS serverip is offered to the client.
1131 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1132 serverip will be stored in the additional environment
1133 variable "dnsip2". The first DNS serverip is always
1134 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1135 is defined.
1137 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1138 to do a dynamic update of a DNS server. To do this, they
1139 need the hostname of the DHCP requester.
1140 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1141 of the "hostname" environment variable is passed as
1142 option 12 to the DHCP server.
1144 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1146 A 32bit value in microseconds for a delay between
1147 receiving a "DHCP Offer" and sending the "DHCP Request".
1148 This fixes a problem with certain DHCP servers that don't
1149 respond 100% of the time to a "DHCP request". E.g. On an
1150 AT91RM9200 processor running at 180MHz, this delay needed
1151 to be *at least* 15,000 usec before a Windows Server 2003
1152 DHCP server would reply 100% of the time. I recommend at
1153 least 50,000 usec to be safe. The alternative is to hope
1154 that one of the retries will be successful but note that
1155 the DHCP timeout and retry process takes a longer than
1156 this delay.
1158 - CDP Options:
1159 CONFIG_CDP_DEVICE_ID
1161 The device id used in CDP trigger frames.
1163 CONFIG_CDP_DEVICE_ID_PREFIX
1165 A two character string which is prefixed to the MAC address
1166 of the device.
1168 CONFIG_CDP_PORT_ID
1170 A printf format string which contains the ascii name of
1171 the port. Normally is set to "eth%d" which sets
1172 eth0 for the first ethernet, eth1 for the second etc.
1174 CONFIG_CDP_CAPABILITIES
1176 A 32bit integer which indicates the device capabilities;
1177 0x00000010 for a normal host which does not forwards.
1179 CONFIG_CDP_VERSION
1181 An ascii string containing the version of the software.
1183 CONFIG_CDP_PLATFORM
1185 An ascii string containing the name of the platform.
1187 CONFIG_CDP_TRIGGER
1189 A 32bit integer sent on the trigger.
1191 CONFIG_CDP_POWER_CONSUMPTION
1193 A 16bit integer containing the power consumption of the
1194 device in .1 of milliwatts.
1196 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1198 A byte containing the id of the VLAN.
1200 - Status LED: CONFIG_STATUS_LED
1202 Several configurations allow to display the current
1203 status using a LED. For instance, the LED will blink
1204 fast while running U-Boot code, stop blinking as
1205 soon as a reply to a BOOTP request was received, and
1206 start blinking slow once the Linux kernel is running
1207 (supported by a status LED driver in the Linux
1208 kernel). Defining CONFIG_STATUS_LED enables this
1209 feature in U-Boot.
1211 - CAN Support: CONFIG_CAN_DRIVER
1213 Defining CONFIG_CAN_DRIVER enables CAN driver support
1214 on those systems that support this (optional)
1215 feature, like the TQM8xxL modules.
1217 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1219 These enable I2C serial bus commands. Defining either of
1220 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1221 include the appropriate I2C driver for the selected cpu.
1223 This will allow you to use i2c commands at the u-boot
1224 command line (as long as you set CONFIG_CMD_I2C in
1225 CONFIG_COMMANDS) and communicate with i2c based realtime
1226 clock chips. See common/cmd_i2c.c for a description of the
1227 command line interface.
1229 CONFIG_I2C_CMD_TREE is a recommended option that places
1230 all I2C commands under a single 'i2c' root command. The
1231 older 'imm', 'imd', 'iprobe' etc. commands are considered
1232 deprecated and may disappear in the future.
1234 CONFIG_HARD_I2C selects a hardware I2C controller.
1236 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1237 bit-banging) driver instead of CPM or similar hardware
1238 support for I2C.
1240 There are several other quantities that must also be
1241 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1243 In both cases you will need to define CFG_I2C_SPEED
1244 to be the frequency (in Hz) at which you wish your i2c bus
1245 to run and CFG_I2C_SLAVE to be the address of this node (ie
1246 the cpu's i2c node address).
1248 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1249 sets the cpu up as a master node and so its address should
1250 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1251 p.16-473). So, set CFG_I2C_SLAVE to 0.
1253 That's all that's required for CONFIG_HARD_I2C.
1255 If you use the software i2c interface (CONFIG_SOFT_I2C)
1256 then the following macros need to be defined (examples are
1257 from include/configs/lwmon.h):
1259 I2C_INIT
1261 (Optional). Any commands necessary to enable the I2C
1262 controller or configure ports.
1264 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1266 I2C_PORT
1268 (Only for MPC8260 CPU). The I/O port to use (the code
1269 assumes both bits are on the same port). Valid values
1270 are 0..3 for ports A..D.
1272 I2C_ACTIVE
1274 The code necessary to make the I2C data line active
1275 (driven). If the data line is open collector, this
1276 define can be null.
1278 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1280 I2C_TRISTATE
1282 The code necessary to make the I2C data line tri-stated
1283 (inactive). If the data line is open collector, this
1284 define can be null.
1286 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1288 I2C_READ
1290 Code that returns TRUE if the I2C data line is high,
1291 FALSE if it is low.
1293 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1295 I2C_SDA(bit)
1297 If <bit> is TRUE, sets the I2C data line high. If it
1298 is FALSE, it clears it (low).
1300 eg: #define I2C_SDA(bit) \
1301 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1302 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1304 I2C_SCL(bit)
1306 If <bit> is TRUE, sets the I2C clock line high. If it
1307 is FALSE, it clears it (low).
1309 eg: #define I2C_SCL(bit) \
1310 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1311 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1313 I2C_DELAY
1315 This delay is invoked four times per clock cycle so this
1316 controls the rate of data transfer. The data rate thus
1317 is 1 / (I2C_DELAY * 4). Often defined to be something
1318 like:
1320 #define I2C_DELAY udelay(2)
1322 CFG_I2C_INIT_BOARD
1324 When a board is reset during an i2c bus transfer
1325 chips might think that the current transfer is still
1326 in progress. On some boards it is possible to access
1327 the i2c SCLK line directly, either by using the
1328 processor pin as a GPIO or by having a second pin
1329 connected to the bus. If this option is defined a
1330 custom i2c_init_board() routine in boards/xxx/board.c
1331 is run early in the boot sequence.
1333 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1335 This option enables configuration of bi_iic_fast[] flags
1336 in u-boot bd_info structure based on u-boot environment
1337 variable "i2cfast". (see also i2cfast)
1339 CONFIG_I2C_MULTI_BUS
1341 This option allows the use of multiple I2C buses, each of which
1342 must have a controller. At any point in time, only one bus is
1343 active. To switch to a different bus, use the 'i2c dev' command.
1344 Note that bus numbering is zero-based.
1346 CFG_I2C_NOPROBES
1348 This option specifies a list of I2C devices that will be skipped
1349 when the 'i2c probe' command is issued (or 'iprobe' using the legacy
1350 command). If CONFIG_I2C_MULTI_BUS is set, specify a list of bus-device
1351 pairs. Otherwise, specify a 1D array of device addresses
1353 e.g.
1354 #undef CONFIG_I2C_MULTI_BUS
1355 #define CFG_I2C_NOPROBES {0x50,0x68}
1357 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1359 #define CONFIG_I2C_MULTI_BUS
1360 #define CFG_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1362 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1364 CFG_SPD_BUS_NUM
1366 If defined, then this indicates the I2C bus number for DDR SPD.
1367 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1369 CFG_RTC_BUS_NUM
1371 If defined, then this indicates the I2C bus number for the RTC.
1372 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1374 CFG_DTT_BUS_NUM
1376 If defined, then this indicates the I2C bus number for the DTT.
1377 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1379 CONFIG_FSL_I2C
1381 Define this option if you want to use Freescale's I2C driver in
1382 drivers/i2c/fsl_i2c.c.
1385 - SPI Support: CONFIG_SPI
1387 Enables SPI driver (so far only tested with
1388 SPI EEPROM, also an instance works with Crystal A/D and
1389 D/As on the SACSng board)
1391 CONFIG_SPI_X
1393 Enables extended (16-bit) SPI EEPROM addressing.
1394 (symmetrical to CONFIG_I2C_X)
1396 CONFIG_SOFT_SPI
1398 Enables a software (bit-bang) SPI driver rather than
1399 using hardware support. This is a general purpose
1400 driver that only requires three general I/O port pins
1401 (two outputs, one input) to function. If this is
1402 defined, the board configuration must define several
1403 SPI configuration items (port pins to use, etc). For
1404 an example, see include/configs/sacsng.h.
1406 CONFIG_HARD_SPI
1408 Enables a hardware SPI driver for general-purpose reads
1409 and writes. As with CONFIG_SOFT_SPI, the board configuration
1410 must define a list of chip-select function pointers.
1411 Currently supported on some MPC8xxx processors. For an
1412 example, see include/configs/mpc8349emds.h.
1414 - FPGA Support: CONFIG_FPGA
1416 Enables FPGA subsystem.
1418 CONFIG_FPGA_<vendor>
1420 Enables support for specific chip vendors.
1421 (ALTERA, XILINX)
1423 CONFIG_FPGA_<family>
1425 Enables support for FPGA family.
1426 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1428 CONFIG_FPGA_COUNT
1430 Specify the number of FPGA devices to support.
1432 CFG_FPGA_PROG_FEEDBACK
1434 Enable printing of hash marks during FPGA configuration.
1436 CFG_FPGA_CHECK_BUSY
1438 Enable checks on FPGA configuration interface busy
1439 status by the configuration function. This option
1440 will require a board or device specific function to
1441 be written.
1443 CONFIG_FPGA_DELAY
1445 If defined, a function that provides delays in the FPGA
1446 configuration driver.
1448 CFG_FPGA_CHECK_CTRLC
1449 Allow Control-C to interrupt FPGA configuration
1451 CFG_FPGA_CHECK_ERROR
1453 Check for configuration errors during FPGA bitfile
1454 loading. For example, abort during Virtex II
1455 configuration if the INIT_B line goes low (which
1456 indicated a CRC error).
1458 CFG_FPGA_WAIT_INIT
1460 Maximum time to wait for the INIT_B line to deassert
1461 after PROB_B has been deasserted during a Virtex II
1462 FPGA configuration sequence. The default time is 500
1463 mS.
1465 CFG_FPGA_WAIT_BUSY
1467 Maximum time to wait for BUSY to deassert during
1468 Virtex II FPGA configuration. The default is 5 mS.
1470 CFG_FPGA_WAIT_CONFIG
1472 Time to wait after FPGA configuration. The default is
1473 200 mS.
1475 - Configuration Management:
1476 CONFIG_IDENT_STRING
1478 If defined, this string will be added to the U-Boot
1479 version information (U_BOOT_VERSION)
1481 - Vendor Parameter Protection:
1483 U-Boot considers the values of the environment
1484 variables "serial#" (Board Serial Number) and
1485 "ethaddr" (Ethernet Address) to be parameters that
1486 are set once by the board vendor / manufacturer, and
1487 protects these variables from casual modification by
1488 the user. Once set, these variables are read-only,
1489 and write or delete attempts are rejected. You can
1490 change this behviour:
1492 If CONFIG_ENV_OVERWRITE is #defined in your config
1493 file, the write protection for vendor parameters is
1494 completely disabled. Anybody can change or delete
1495 these parameters.
1497 Alternatively, if you #define _both_ CONFIG_ETHADDR
1498 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1499 ethernet address is installed in the environment,
1500 which can be changed exactly ONCE by the user. [The
1501 serial# is unaffected by this, i. e. it remains
1502 read-only.]
1504 - Protected RAM:
1505 CONFIG_PRAM
1507 Define this variable to enable the reservation of
1508 "protected RAM", i. e. RAM which is not overwritten
1509 by U-Boot. Define CONFIG_PRAM to hold the number of
1510 kB you want to reserve for pRAM. You can overwrite
1511 this default value by defining an environment
1512 variable "pram" to the number of kB you want to
1513 reserve. Note that the board info structure will
1514 still show the full amount of RAM. If pRAM is
1515 reserved, a new environment variable "mem" will
1516 automatically be defined to hold the amount of
1517 remaining RAM in a form that can be passed as boot
1518 argument to Linux, for instance like that:
1520 setenv bootargs ... mem=\${mem}
1521 saveenv
1523 This way you can tell Linux not to use this memory,
1524 either, which results in a memory region that will
1525 not be affected by reboots.
1527 *WARNING* If your board configuration uses automatic
1528 detection of the RAM size, you must make sure that
1529 this memory test is non-destructive. So far, the
1530 following board configurations are known to be
1531 "pRAM-clean":
1533 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1534 HERMES, IP860, RPXlite, LWMON, LANTEC,
1535 PCU_E, FLAGADM, TQM8260
1537 - Error Recovery:
1538 CONFIG_PANIC_HANG
1540 Define this variable to stop the system in case of a
1541 fatal error, so that you have to reset it manually.
1542 This is probably NOT a good idea for an embedded
1543 system where you want to system to reboot
1544 automatically as fast as possible, but it may be
1545 useful during development since you can try to debug
1546 the conditions that lead to the situation.
1548 CONFIG_NET_RETRY_COUNT
1550 This variable defines the number of retries for
1551 network operations like ARP, RARP, TFTP, or BOOTP
1552 before giving up the operation. If not defined, a
1553 default value of 5 is used.
1555 - Command Interpreter:
1556 CONFIG_AUTO_COMPLETE
1558 Enable auto completion of commands using TAB.
1560 Note that this feature has NOT been implemented yet
1561 for the "hush" shell.
1564 CFG_HUSH_PARSER
1566 Define this variable to enable the "hush" shell (from
1567 Busybox) as command line interpreter, thus enabling
1568 powerful command line syntax like
1569 if...then...else...fi conditionals or `&&' and '||'
1570 constructs ("shell scripts").
1572 If undefined, you get the old, much simpler behaviour
1573 with a somewhat smaller memory footprint.
1576 CFG_PROMPT_HUSH_PS2
1578 This defines the secondary prompt string, which is
1579 printed when the command interpreter needs more input
1580 to complete a command. Usually "> ".
1582 Note:
1584 In the current implementation, the local variables
1585 space and global environment variables space are
1586 separated. Local variables are those you define by
1587 simply typing `name=value'. To access a local
1588 variable later on, you have write `$name' or
1589 `${name}'; to execute the contents of a variable
1590 directly type `$name' at the command prompt.
1592 Global environment variables are those you use
1593 setenv/printenv to work with. To run a command stored
1594 in such a variable, you need to use the run command,
1595 and you must not use the '$' sign to access them.
1597 To store commands and special characters in a
1598 variable, please use double quotation marks
1599 surrounding the whole text of the variable, instead
1600 of the backslashes before semicolons and special
1601 symbols.
1603 - Commandline Editing and History:
1604 CONFIG_CMDLINE_EDITING
1606 Enable editiong and History functions for interactive
1607 commandline input operations
1609 - Default Environment:
1610 CONFIG_EXTRA_ENV_SETTINGS
1612 Define this to contain any number of null terminated
1613 strings (variable = value pairs) that will be part of
1614 the default environment compiled into the boot image.
1616 For example, place something like this in your
1617 board's config file:
1619 #define CONFIG_EXTRA_ENV_SETTINGS \
1620 "myvar1=value1\0" \
1621 "myvar2=value2\0"
1623 Warning: This method is based on knowledge about the
1624 internal format how the environment is stored by the
1625 U-Boot code. This is NOT an official, exported
1626 interface! Although it is unlikely that this format
1627 will change soon, there is no guarantee either.
1628 You better know what you are doing here.
1630 Note: overly (ab)use of the default environment is
1631 discouraged. Make sure to check other ways to preset
1632 the environment like the autoscript function or the
1633 boot command first.
1635 - DataFlash Support:
1636 CONFIG_HAS_DATAFLASH
1638 Defining this option enables DataFlash features and
1639 allows to read/write in Dataflash via the standard
1640 commands cp, md...
1642 - SystemACE Support:
1643 CONFIG_SYSTEMACE
1645 Adding this option adds support for Xilinx SystemACE
1646 chips attached via some sort of local bus. The address
1647 of the chip must alsh be defined in the
1648 CFG_SYSTEMACE_BASE macro. For example:
1650 #define CONFIG_SYSTEMACE
1651 #define CFG_SYSTEMACE_BASE 0xf0000000
1653 When SystemACE support is added, the "ace" device type
1654 becomes available to the fat commands, i.e. fatls.
1656 - TFTP Fixed UDP Port:
1657 CONFIG_TFTP_PORT
1659 If this is defined, the environment variable tftpsrcp
1660 is used to supply the TFTP UDP source port value.
1661 If tftpsrcp isn't defined, the normal pseudo-random port
1662 number generator is used.
1664 Also, the environment variable tftpdstp is used to supply
1665 the TFTP UDP destination port value. If tftpdstp isn't
1666 defined, the normal port 69 is used.
1668 The purpose for tftpsrcp is to allow a TFTP server to
1669 blindly start the TFTP transfer using the pre-configured
1670 target IP address and UDP port. This has the effect of
1671 "punching through" the (Windows XP) firewall, allowing
1672 the remainder of the TFTP transfer to proceed normally.
1673 A better solution is to properly configure the firewall,
1674 but sometimes that is not allowed.
1676 - Show boot progress:
1677 CONFIG_SHOW_BOOT_PROGRESS
1679 Defining this option allows to add some board-
1680 specific code (calling a user-provided function
1681 "show_boot_progress(int)") that enables you to show
1682 the system's boot progress on some display (for
1683 example, some LED's) on your board. At the moment,
1684 the following checkpoints are implemented:
1686 Legacy uImage format:
1688 Arg Where When
1689 1 common/cmd_bootm.c before attempting to boot an image
1690 -1 common/cmd_bootm.c Image header has bad magic number
1691 2 common/cmd_bootm.c Image header has correct magic number
1692 -2 common/cmd_bootm.c Image header has bad checksum
1693 3 common/cmd_bootm.c Image header has correct checksum
1694 -3 common/cmd_bootm.c Image data has bad checksum
1695 4 common/cmd_bootm.c Image data has correct checksum
1696 -4 common/cmd_bootm.c Image is for unsupported architecture
1697 5 common/cmd_bootm.c Architecture check OK
1698 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1699 6 common/cmd_bootm.c Image Type check OK
1700 -6 common/cmd_bootm.c gunzip uncompression error
1701 -7 common/cmd_bootm.c Unimplemented compression type
1702 7 common/cmd_bootm.c Uncompression OK
1703 8 common/cmd_bootm.c No uncompress/copy overwrite error
1704 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1706 9 common/image.c Start initial ramdisk verification
1707 -10 common/image.c Ramdisk header has bad magic number
1708 -11 common/image.c Ramdisk header has bad checksum
1709 10 common/image.c Ramdisk header is OK
1710 -12 common/image.c Ramdisk data has bad checksum
1711 11 common/image.c Ramdisk data has correct checksum
1712 12 common/image.c Ramdisk verification complete, start loading
1713 -13 common/image.c Wrong Image Type (not PPC Linux Ramdisk)
1714 13 common/image.c Start multifile image verification
1715 14 common/image.c No initial ramdisk, no multifile, continue.
1717 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1719 -30 lib_ppc/board.c Fatal error, hang the system
1720 -31 post/post.c POST test failed, detected by post_output_backlog()
1721 -32 post/post.c POST test failed, detected by post_run_single()
1723 34 common/cmd_doc.c before loading a Image from a DOC device
1724 -35 common/cmd_doc.c Bad usage of "doc" command
1725 35 common/cmd_doc.c correct usage of "doc" command
1726 -36 common/cmd_doc.c No boot device
1727 36 common/cmd_doc.c correct boot device
1728 -37 common/cmd_doc.c Unknown Chip ID on boot device
1729 37 common/cmd_doc.c correct chip ID found, device available
1730 -38 common/cmd_doc.c Read Error on boot device
1731 38 common/cmd_doc.c reading Image header from DOC device OK
1732 -39 common/cmd_doc.c Image header has bad magic number
1733 39 common/cmd_doc.c Image header has correct magic number
1734 -40 common/cmd_doc.c Error reading Image from DOC device
1735 40 common/cmd_doc.c Image header has correct magic number
1736 41 common/cmd_ide.c before loading a Image from a IDE device
1737 -42 common/cmd_ide.c Bad usage of "ide" command
1738 42 common/cmd_ide.c correct usage of "ide" command
1739 -43 common/cmd_ide.c No boot device
1740 43 common/cmd_ide.c boot device found
1741 -44 common/cmd_ide.c Device not available
1742 44 common/cmd_ide.c Device available
1743 -45 common/cmd_ide.c wrong partition selected
1744 45 common/cmd_ide.c partition selected
1745 -46 common/cmd_ide.c Unknown partition table
1746 46 common/cmd_ide.c valid partition table found
1747 -47 common/cmd_ide.c Invalid partition type
1748 47 common/cmd_ide.c correct partition type
1749 -48 common/cmd_ide.c Error reading Image Header on boot device
1750 48 common/cmd_ide.c reading Image Header from IDE device OK
1751 -49 common/cmd_ide.c Image header has bad magic number
1752 49 common/cmd_ide.c Image header has correct magic number
1753 -50 common/cmd_ide.c Image header has bad checksum
1754 50 common/cmd_ide.c Image header has correct checksum
1755 -51 common/cmd_ide.c Error reading Image from IDE device
1756 51 common/cmd_ide.c reading Image from IDE device OK
1757 52 common/cmd_nand.c before loading a Image from a NAND device
1758 -53 common/cmd_nand.c Bad usage of "nand" command
1759 53 common/cmd_nand.c correct usage of "nand" command
1760 -54 common/cmd_nand.c No boot device
1761 54 common/cmd_nand.c boot device found
1762 -55 common/cmd_nand.c Unknown Chip ID on boot device
1763 55 common/cmd_nand.c correct chip ID found, device available
1764 -56 common/cmd_nand.c Error reading Image Header on boot device
1765 56 common/cmd_nand.c reading Image Header from NAND device OK
1766 -57 common/cmd_nand.c Image header has bad magic number
1767 57 common/cmd_nand.c Image header has correct magic number
1768 -58 common/cmd_nand.c Error reading Image from NAND device
1769 58 common/cmd_nand.c reading Image from NAND device OK
1771 -60 common/env_common.c Environment has a bad CRC, using default
1773 64 net/eth.c starting with Ethernetconfiguration.
1774 -64 net/eth.c no Ethernet found.
1775 65 net/eth.c Ethernet found.
1777 -80 common/cmd_net.c usage wrong
1778 80 common/cmd_net.c before calling NetLoop()
1779 -81 common/cmd_net.c some error in NetLoop() occured
1780 81 common/cmd_net.c NetLoop() back without error
1781 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
1782 82 common/cmd_net.c trying automatic boot
1783 83 common/cmd_net.c running autoscript
1784 -83 common/cmd_net.c some error in automatic boot or autoscript
1785 84 common/cmd_net.c end without errors
1787 FIT uImage format:
1789 Arg Where When
1790 100 common/cmd_bootm.c Kernel FIT Image has correct format
1791 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
1792 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
1793 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
1794 102 common/cmd_bootm.c Kernel unit name specified
1795 -103 common/cmd_bootm.c Can't get kernel subimage node offset
1796 103 common/cmd_bootm.c Found configuration node
1797 104 common/cmd_bootm.c Got kernel subimage node offset
1798 -104 common/cmd_bootm.c Kernel subimage hash verification failed
1799 105 common/cmd_bootm.c Kernel subimage hash verification OK
1800 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
1801 106 common/cmd_bootm.c Architecture check OK
1802 -106 common/cmd_bootm.c Kernel subimage has wrong typea
1803 107 common/cmd_bootm.c Kernel subimge type OK
1804 -107 common/cmd_bootm.c Can't get kernel subimage data/size
1805 108 common/cmd_bootm.c Got kernel subimage data/size
1806 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
1807 -109 common/cmd_bootm.c Can't get kernel subimage type
1808 -110 common/cmd_bootm.c Can't get kernel subimage comp
1809 -111 common/cmd_bootm.c Can't get kernel subimage os
1810 -112 common/cmd_bootm.c Can't get kernel subimage load address
1811 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
1813 120 common/image.c Start initial ramdisk verification
1814 -120 common/image.c Ramdisk FIT image has incorrect format
1815 121 common/image.c Ramdisk FIT image has correct format
1816 122 common/image.c No Ramdisk subimage unit name, using configuration
1817 -122 common/image.c Can't get configuration for ramdisk subimage
1818 123 common/image.c Ramdisk unit name specified
1819 -124 common/image.c Can't get ramdisk subimage node offset
1820 125 common/image.c Got ramdisk subimage node offset
1821 -125 common/image.c Ramdisk subimage hash verification failed
1822 126 common/image.c Ramdisk subimage hash verification OK
1823 -126 common/image.c Ramdisk subimage for unsupported architecture
1824 127 common/image.c Architecture check OK
1825 -127 common/image.c Can't get ramdisk subimage data/size
1826 128 common/image.c Got ramdisk subimage data/size
1827 129 common/image.c Can't get ramdisk load address
1828 -129 common/image.c Got ramdisk load address
1830 -130 common/cmd_doc.c Icorrect FIT image format
1831 131 common/cmd_doc.c FIT image format OK
1833 -140 common/cmd_ide.c Icorrect FIT image format
1834 141 common/cmd_ide.c FIT image format OK
1836 -150 common/cmd_nand.c Icorrect FIT image format
1837 151 common/cmd_nand.c FIT image format OK
1840 Modem Support:
1841 --------------
1843 [so far only for SMDK2400 and TRAB boards]
1845 - Modem support endable:
1846 CONFIG_MODEM_SUPPORT
1848 - RTS/CTS Flow control enable:
1849 CONFIG_HWFLOW
1851 - Modem debug support:
1852 CONFIG_MODEM_SUPPORT_DEBUG
1854 Enables debugging stuff (char screen[1024], dbg())
1855 for modem support. Useful only with BDI2000.
1857 - Interrupt support (PPC):
1859 There are common interrupt_init() and timer_interrupt()
1860 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1861 for cpu specific initialization. interrupt_init_cpu()
1862 should set decrementer_count to appropriate value. If
1863 cpu resets decrementer automatically after interrupt
1864 (ppc4xx) it should set decrementer_count to zero.
1865 timer_interrupt() calls timer_interrupt_cpu() for cpu
1866 specific handling. If board has watchdog / status_led
1867 / other_activity_monitor it works automatically from
1868 general timer_interrupt().
1870 - General:
1872 In the target system modem support is enabled when a
1873 specific key (key combination) is pressed during
1874 power-on. Otherwise U-Boot will boot normally
1875 (autoboot). The key_pressed() fuction is called from
1876 board_init(). Currently key_pressed() is a dummy
1877 function, returning 1 and thus enabling modem
1878 initialization.
1880 If there are no modem init strings in the
1881 environment, U-Boot proceed to autoboot; the
1882 previous output (banner, info printfs) will be
1883 supressed, though.
1885 See also: doc/README.Modem
1888 Configuration Settings:
1889 -----------------------
1891 - CFG_LONGHELP: Defined when you want long help messages included;
1892 undefine this when you're short of memory.
1894 - CFG_PROMPT: This is what U-Boot prints on the console to
1895 prompt for user input.
1897 - CFG_CBSIZE: Buffer size for input from the Console
1899 - CFG_PBSIZE: Buffer size for Console output
1901 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1903 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1904 the application (usually a Linux kernel) when it is
1905 booted
1907 - CFG_BAUDRATE_TABLE:
1908 List of legal baudrate settings for this board.
1910 - CFG_CONSOLE_INFO_QUIET
1911 Suppress display of console information at boot.
1913 - CFG_CONSOLE_IS_IN_ENV
1914 If the board specific function
1915 extern int overwrite_console (void);
1916 returns 1, the stdin, stderr and stdout are switched to the
1917 serial port, else the settings in the environment are used.
1919 - CFG_CONSOLE_OVERWRITE_ROUTINE
1920 Enable the call to overwrite_console().
1922 - CFG_CONSOLE_ENV_OVERWRITE
1923 Enable overwrite of previous console environment settings.
1925 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1926 Begin and End addresses of the area used by the
1927 simple memory test.
1929 - CFG_ALT_MEMTEST:
1930 Enable an alternate, more extensive memory test.
1932 - CFG_MEMTEST_SCRATCH:
1933 Scratch address used by the alternate memory test
1934 You only need to set this if address zero isn't writeable
1936 - CFG_MEM_TOP_HIDE (PPC only):
1937 If CFG_MEM_TOP_HIDE is defined in the board config header,
1938 this specified memory area will get subtracted from the top
1939 (end) of ram and won't get "touched" at all by U-Boot. By
1940 fixing up gd->ram_size the Linux kernel should gets passed
1941 the now "corrected" memory size and won't touch it either.
1942 This should work for arch/ppc and arch/powerpc. Only Linux
1943 board ports in arch/powerpc with bootwrapper support that
1944 recalculate the memory size from the SDRAM controller setup
1945 will have to get fixed in Linux additionally.
1947 This option can be used as a workaround for the 440EPx/GRx
1948 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
1949 be touched.
1951 WARNING: Please make sure that this value is a multiple of
1952 the Linux page size (normally 4k). If this is not the case,
1953 then the end address of the Linux memory will be located at a
1954 non page size aligned address and this could cause major
1955 problems.
1957 - CFG_TFTP_LOADADDR:
1958 Default load address for network file downloads
1960 - CFG_LOADS_BAUD_CHANGE:
1961 Enable temporary baudrate change while serial download
1963 - CFG_SDRAM_BASE:
1964 Physical start address of SDRAM. _Must_ be 0 here.
1966 - CFG_MBIO_BASE:
1967 Physical start address of Motherboard I/O (if using a
1968 Cogent motherboard)
1970 - CFG_FLASH_BASE:
1971 Physical start address of Flash memory.
1973 - CFG_MONITOR_BASE:
1974 Physical start address of boot monitor code (set by
1975 make config files to be same as the text base address
1976 (TEXT_BASE) used when linking) - same as
1977 CFG_FLASH_BASE when booting from flash.
1979 - CFG_MONITOR_LEN:
1980 Size of memory reserved for monitor code, used to
1981 determine _at_compile_time_ (!) if the environment is
1982 embedded within the U-Boot image, or in a separate
1983 flash sector.
1985 - CFG_MALLOC_LEN:
1986 Size of DRAM reserved for malloc() use.
1988 - CFG_BOOTM_LEN:
1989 Normally compressed uImages are limited to an
1990 uncompressed size of 8 MBytes. If this is not enough,
1991 you can define CFG_BOOTM_LEN in your board config file
1992 to adjust this setting to your needs.
1994 - CFG_BOOTMAPSZ:
1995 Maximum size of memory mapped by the startup code of
1996 the Linux kernel; all data that must be processed by
1997 the Linux kernel (bd_info, boot arguments, eventually
1998 initrd image) must be put below this limit.
2000 - CFG_MAX_FLASH_BANKS:
2001 Max number of Flash memory banks
2003 - CFG_MAX_FLASH_SECT:
2004 Max number of sectors on a Flash chip
2006 - CFG_FLASH_ERASE_TOUT:
2007 Timeout for Flash erase operations (in ms)
2009 - CFG_FLASH_WRITE_TOUT:
2010 Timeout for Flash write operations (in ms)
2012 - CFG_FLASH_LOCK_TOUT
2013 Timeout for Flash set sector lock bit operation (in ms)
2015 - CFG_FLASH_UNLOCK_TOUT
2016 Timeout for Flash clear lock bits operation (in ms)
2018 - CFG_FLASH_PROTECTION
2019 If defined, hardware flash sectors protection is used
2020 instead of U-Boot software protection.
2022 - CFG_DIRECT_FLASH_TFTP:
2024 Enable TFTP transfers directly to flash memory;
2025 without this option such a download has to be
2026 performed in two steps: (1) download to RAM, and (2)
2027 copy from RAM to flash.
2029 The two-step approach is usually more reliable, since
2030 you can check if the download worked before you erase
2031 the flash, but in some situations (when sytem RAM is
2032 too limited to allow for a tempory copy of the
2033 downloaded image) this option may be very useful.
2035 - CFG_FLASH_CFI:
2036 Define if the flash driver uses extra elements in the
2037 common flash structure for storing flash geometry.
2039 - CFG_FLASH_CFI_DRIVER
2040 This option also enables the building of the cfi_flash driver
2041 in the drivers directory
2043 - CFG_FLASH_QUIET_TEST
2044 If this option is defined, the common CFI flash doesn't
2045 print it's warning upon not recognized FLASH banks. This
2046 is useful, if some of the configured banks are only
2047 optionally available.
2049 - CONFIG_FLASH_SHOW_PROGRESS
2050 If defined (must be an integer), print out countdown
2051 digits and dots. Recommended value: 45 (9..1) for 80
2052 column displays, 15 (3..1) for 40 column displays.
2054 - CFG_RX_ETH_BUFFER:
2055 Defines the number of ethernet receive buffers. On some
2056 ethernet controllers it is recommended to set this value
2057 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2058 buffers can be full shortly after enabling the interface
2059 on high ethernet traffic.
2060 Defaults to 4 if not defined.
2062 The following definitions that deal with the placement and management
2063 of environment data (variable area); in general, we support the
2064 following configurations:
2066 - CFG_ENV_IS_IN_FLASH:
2068 Define this if the environment is in flash memory.
2070 a) The environment occupies one whole flash sector, which is
2071 "embedded" in the text segment with the U-Boot code. This
2072 happens usually with "bottom boot sector" or "top boot
2073 sector" type flash chips, which have several smaller
2074 sectors at the start or the end. For instance, such a
2075 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2076 such a case you would place the environment in one of the
2077 4 kB sectors - with U-Boot code before and after it. With
2078 "top boot sector" type flash chips, you would put the
2079 environment in one of the last sectors, leaving a gap
2080 between U-Boot and the environment.
2082 - CFG_ENV_OFFSET:
2084 Offset of environment data (variable area) to the
2085 beginning of flash memory; for instance, with bottom boot
2086 type flash chips the second sector can be used: the offset
2087 for this sector is given here.
2089 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
2091 - CFG_ENV_ADDR:
2093 This is just another way to specify the start address of
2094 the flash sector containing the environment (instead of
2095 CFG_ENV_OFFSET).
2097 - CFG_ENV_SECT_SIZE:
2099 Size of the sector containing the environment.
2102 b) Sometimes flash chips have few, equal sized, BIG sectors.
2103 In such a case you don't want to spend a whole sector for
2104 the environment.
2106 - CFG_ENV_SIZE:
2108 If you use this in combination with CFG_ENV_IS_IN_FLASH
2109 and CFG_ENV_SECT_SIZE, you can specify to use only a part
2110 of this flash sector for the environment. This saves
2111 memory for the RAM copy of the environment.
2113 It may also save flash memory if you decide to use this
2114 when your environment is "embedded" within U-Boot code,
2115 since then the remainder of the flash sector could be used
2116 for U-Boot code. It should be pointed out that this is
2117 STRONGLY DISCOURAGED from a robustness point of view:
2118 updating the environment in flash makes it always
2119 necessary to erase the WHOLE sector. If something goes
2120 wrong before the contents has been restored from a copy in
2121 RAM, your target system will be dead.
2123 - CFG_ENV_ADDR_REDUND
2124 CFG_ENV_SIZE_REDUND
2126 These settings describe a second storage area used to hold
2127 a redundand copy of the environment data, so that there is
2128 a valid backup copy in case there is a power failure during
2129 a "saveenv" operation.
2131 BE CAREFUL! Any changes to the flash layout, and some changes to the
2132 source code will make it necessary to adapt <board>/u-boot.lds*
2133 accordingly!
2136 - CFG_ENV_IS_IN_NVRAM:
2138 Define this if you have some non-volatile memory device
2139 (NVRAM, battery buffered SRAM) which you want to use for the
2140 environment.
2142 - CFG_ENV_ADDR:
2143 - CFG_ENV_SIZE:
2145 These two #defines are used to determin the memory area you
2146 want to use for environment. It is assumed that this memory
2147 can just be read and written to, without any special
2148 provision.
2150 BE CAREFUL! The first access to the environment happens quite early
2151 in U-Boot initalization (when we try to get the setting of for the
2152 console baudrate). You *MUST* have mappend your NVRAM area then, or
2153 U-Boot will hang.
2155 Please note that even with NVRAM we still use a copy of the
2156 environment in RAM: we could work on NVRAM directly, but we want to
2157 keep settings there always unmodified except somebody uses "saveenv"
2158 to save the current settings.
2161 - CFG_ENV_IS_IN_EEPROM:
2163 Use this if you have an EEPROM or similar serial access
2164 device and a driver for it.
2166 - CFG_ENV_OFFSET:
2167 - CFG_ENV_SIZE:
2169 These two #defines specify the offset and size of the
2170 environment area within the total memory of your EEPROM.
2172 - CFG_I2C_EEPROM_ADDR:
2173 If defined, specified the chip address of the EEPROM device.
2174 The default address is zero.
2176 - CFG_EEPROM_PAGE_WRITE_BITS:
2177 If defined, the number of bits used to address bytes in a
2178 single page in the EEPROM device. A 64 byte page, for example
2179 would require six bits.
2181 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
2182 If defined, the number of milliseconds to delay between
2183 page writes. The default is zero milliseconds.
2185 - CFG_I2C_EEPROM_ADDR_LEN:
2186 The length in bytes of the EEPROM memory array address. Note
2187 that this is NOT the chip address length!
2189 - CFG_I2C_EEPROM_ADDR_OVERFLOW:
2190 EEPROM chips that implement "address overflow" are ones
2191 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2192 address and the extra bits end up in the "chip address" bit
2193 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2194 byte chips.
2196 Note that we consider the length of the address field to
2197 still be one byte because the extra address bits are hidden
2198 in the chip address.
2200 - CFG_EEPROM_SIZE:
2201 The size in bytes of the EEPROM device.
2204 - CFG_ENV_IS_IN_DATAFLASH:
2206 Define this if you have a DataFlash memory device which you
2207 want to use for the environment.
2209 - CFG_ENV_OFFSET:
2210 - CFG_ENV_ADDR:
2211 - CFG_ENV_SIZE:
2213 These three #defines specify the offset and size of the
2214 environment area within the total memory of your DataFlash placed
2215 at the specified address.
2217 - CFG_ENV_IS_IN_NAND:
2219 Define this if you have a NAND device which you want to use
2220 for the environment.
2222 - CFG_ENV_OFFSET:
2223 - CFG_ENV_SIZE:
2225 These two #defines specify the offset and size of the environment
2226 area within the first NAND device.
2228 - CFG_ENV_OFFSET_REDUND
2230 This setting describes a second storage area of CFG_ENV_SIZE
2231 size used to hold a redundant copy of the environment data,
2232 so that there is a valid backup copy in case there is a
2233 power failure during a "saveenv" operation.
2235 Note: CFG_ENV_OFFSET and CFG_ENV_OFFSET_REDUND must be aligned
2236 to a block boundary, and CFG_ENV_SIZE must be a multiple of
2237 the NAND devices block size.
2239 - CFG_SPI_INIT_OFFSET
2241 Defines offset to the initial SPI buffer area in DPRAM. The
2242 area is used at an early stage (ROM part) if the environment
2243 is configured to reside in the SPI EEPROM: We need a 520 byte
2244 scratch DPRAM area. It is used between the two initialization
2245 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2246 to be a good choice since it makes it far enough from the
2247 start of the data area as well as from the stack pointer.
2249 Please note that the environment is read-only until the monitor
2250 has been relocated to RAM and a RAM copy of the environment has been
2251 created; also, when using EEPROM you will have to use getenv_r()
2252 until then to read environment variables.
2254 The environment is protected by a CRC32 checksum. Before the monitor
2255 is relocated into RAM, as a result of a bad CRC you will be working
2256 with the compiled-in default environment - *silently*!!! [This is
2257 necessary, because the first environment variable we need is the
2258 "baudrate" setting for the console - if we have a bad CRC, we don't
2259 have any device yet where we could complain.]
2261 Note: once the monitor has been relocated, then it will complain if
2262 the default environment is used; a new CRC is computed as soon as you
2263 use the "saveenv" command to store a valid environment.
2265 - CFG_FAULT_ECHO_LINK_DOWN:
2266 Echo the inverted Ethernet link state to the fault LED.
2268 Note: If this option is active, then CFG_FAULT_MII_ADDR
2269 also needs to be defined.
2271 - CFG_FAULT_MII_ADDR:
2272 MII address of the PHY to check for the Ethernet link state.
2274 - CFG_64BIT_VSPRINTF:
2275 Makes vsprintf (and all *printf functions) support printing
2276 of 64bit values by using the L quantifier
2278 - CFG_64BIT_STRTOUL:
2279 Adds simple_strtoull that returns a 64bit value
2281 Low Level (hardware related) configuration options:
2282 ---------------------------------------------------
2284 - CFG_CACHELINE_SIZE:
2285 Cache Line Size of the CPU.
2287 - CFG_DEFAULT_IMMR:
2288 Default address of the IMMR after system reset.
2290 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2291 and RPXsuper) to be able to adjust the position of
2292 the IMMR register after a reset.
2294 - Floppy Disk Support:
2295 CFG_FDC_DRIVE_NUMBER
2297 the default drive number (default value 0)
2299 CFG_ISA_IO_STRIDE
2301 defines the spacing between fdc chipset registers
2302 (default value 1)
2304 CFG_ISA_IO_OFFSET
2306 defines the offset of register from address. It
2307 depends on which part of the data bus is connected to
2308 the fdc chipset. (default value 0)
2310 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
2311 CFG_FDC_DRIVE_NUMBER are undefined, they take their
2312 default value.
2314 if CFG_FDC_HW_INIT is defined, then the function
2315 fdc_hw_init() is called at the beginning of the FDC
2316 setup. fdc_hw_init() must be provided by the board
2317 source code. It is used to make hardware dependant
2318 initializations.
2320 - CFG_IMMR: Physical address of the Internal Memory.
2321 DO NOT CHANGE unless you know exactly what you're
2322 doing! (11-4) [MPC8xx/82xx systems only]
2324 - CFG_INIT_RAM_ADDR:
2326 Start address of memory area that can be used for
2327 initial data and stack; please note that this must be
2328 writable memory that is working WITHOUT special
2329 initialization, i. e. you CANNOT use normal RAM which
2330 will become available only after programming the
2331 memory controller and running certain initialization
2332 sequences.
2334 U-Boot uses the following memory types:
2335 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2336 - MPC824X: data cache
2337 - PPC4xx: data cache
2339 - CFG_GBL_DATA_OFFSET:
2341 Offset of the initial data structure in the memory
2342 area defined by CFG_INIT_RAM_ADDR. Usually
2343 CFG_GBL_DATA_OFFSET is chosen such that the initial
2344 data is located at the end of the available space
2345 (sometimes written as (CFG_INIT_RAM_END -
2346 CFG_INIT_DATA_SIZE), and the initial stack is just
2347 below that area (growing from (CFG_INIT_RAM_ADDR +
2348 CFG_GBL_DATA_OFFSET) downward.
2350 Note:
2351 On the MPC824X (or other systems that use the data
2352 cache for initial memory) the address chosen for
2353 CFG_INIT_RAM_ADDR is basically arbitrary - it must
2354 point to an otherwise UNUSED address space between
2355 the top of RAM and the start of the PCI space.
2357 - CFG_SIUMCR: SIU Module Configuration (11-6)
2359 - CFG_SYPCR: System Protection Control (11-9)
2361 - CFG_TBSCR: Time Base Status and Control (11-26)
2363 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
2365 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2367 - CFG_SCCR: System Clock and reset Control Register (15-27)
2369 - CFG_OR_TIMING_SDRAM:
2370 SDRAM timing
2372 - CFG_MAMR_PTA:
2373 periodic timer for refresh
2375 - CFG_DER: Debug Event Register (37-47)
2377 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
2378 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
2379 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
2380 CFG_BR1_PRELIM:
2381 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2383 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2384 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
2385 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
2386 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2388 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
2389 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
2390 Machine Mode Register and Memory Periodic Timer
2391 Prescaler definitions (SDRAM timing)
2393 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
2394 enable I2C microcode relocation patch (MPC8xx);
2395 define relocation offset in DPRAM [DSP2]
2397 - CFG_SMC_UCODE_PATCH, CFG_SMC_DPMEM_OFFSET [0x1FC0]:
2398 enable SMC microcode relocation patch (MPC8xx);
2399 define relocation offset in DPRAM [SMC1]
2401 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2402 enable SPI microcode relocation patch (MPC8xx);
2403 define relocation offset in DPRAM [SCC4]
2405 - CFG_USE_OSCCLK:
2406 Use OSCM clock mode on MBX8xx board. Be careful,
2407 wrong setting might damage your board. Read
2408 doc/README.MBX before setting this variable!
2410 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2411 Offset of the bootmode word in DPRAM used by post
2412 (Power On Self Tests). This definition overrides
2413 #define'd default value in commproc.h resp.
2414 cpm_8260.h.
2416 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
2417 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
2418 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
2419 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
2420 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2421 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
2422 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
2423 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
2424 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2426 - CONFIG_SPD_EEPROM
2427 Get DDR timing information from an I2C EEPROM. Common
2428 with pluggable memory modules such as SODIMMs
2430 SPD_EEPROM_ADDRESS
2431 I2C address of the SPD EEPROM
2433 - CFG_SPD_BUS_NUM
2434 If SPD EEPROM is on an I2C bus other than the first
2435 one, specify here. Note that the value must resolve
2436 to something your driver can deal with.
2438 - CFG_83XX_DDR_USES_CS0
2439 Only for 83xx systems. If specified, then DDR should
2440 be configured using CS0 and CS1 instead of CS2 and CS3.
2442 - CFG_83XX_DDR_USES_CS0
2443 Only for 83xx systems. If specified, then DDR should
2444 be configured using CS0 and CS1 instead of CS2 and CS3.
2446 - CONFIG_ETHER_ON_FEC[12]
2447 Define to enable FEC[12] on a 8xx series processor.
2449 - CONFIG_FEC[12]_PHY
2450 Define to the hardcoded PHY address which corresponds
2451 to the given FEC; i. e.
2452 #define CONFIG_FEC1_PHY 4
2453 means that the PHY with address 4 is connected to FEC1
2455 When set to -1, means to probe for first available.
2457 - CONFIG_FEC[12]_PHY_NORXERR
2458 The PHY does not have a RXERR line (RMII only).
2459 (so program the FEC to ignore it).
2461 - CONFIG_RMII
2462 Enable RMII mode for all FECs.
2463 Note that this is a global option, we can't
2464 have one FEC in standard MII mode and another in RMII mode.
2466 - CONFIG_CRC32_VERIFY
2467 Add a verify option to the crc32 command.
2468 The syntax is:
2470 => crc32 -v <address> <count> <crc32>
2472 Where address/count indicate a memory area
2473 and crc32 is the correct crc32 which the
2474 area should have.
2476 - CONFIG_LOOPW
2477 Add the "loopw" memory command. This only takes effect if
2478 the memory commands are activated globally (CONFIG_CMD_MEM).
2480 - CONFIG_MX_CYCLIC
2481 Add the "mdc" and "mwc" memory commands. These are cyclic
2482 "md/mw" commands.
2483 Examples:
2485 => mdc.b 10 4 500
2486 This command will print 4 bytes (10,11,12,13) each 500 ms.
2488 => mwc.l 100 12345678 10
2489 This command will write 12345678 to address 100 all 10 ms.
2491 This only takes effect if the memory commands are activated
2492 globally (CONFIG_CMD_MEM).
2494 - CONFIG_SKIP_LOWLEVEL_INIT
2495 - CONFIG_SKIP_RELOCATE_UBOOT
2497 [ARM only] If these variables are defined, then
2498 certain low level initializations (like setting up
2499 the memory controller) are omitted and/or U-Boot does
2500 not relocate itself into RAM.
2501 Normally these variables MUST NOT be defined. The
2502 only exception is when U-Boot is loaded (to RAM) by
2503 some other boot loader or by a debugger which
2504 performs these intializations itself.
2507 Building the Software:
2508 ======================
2510 Building U-Boot has been tested in several native build environments
2511 and in many different cross environments. Of course we cannot support
2512 all possibly existing versions of cross development tools in all
2513 (potentially obsolete) versions. In case of tool chain problems we
2514 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2515 which is extensively used to build and test U-Boot.
2517 If you are not using a native environment, it is assumed that you
2518 have GNU cross compiling tools available in your path. In this case,
2519 you must set the environment variable CROSS_COMPILE in your shell.
2520 Note that no changes to the Makefile or any other source files are
2521 necessary. For example using the ELDK on a 4xx CPU, please enter:
2523 $ CROSS_COMPILE=ppc_4xx-
2524 $ export CROSS_COMPILE
2526 U-Boot is intended to be simple to build. After installing the
2527 sources you must configure U-Boot for one specific board type. This
2528 is done by typing:
2530 make NAME_config
2532 where "NAME_config" is the name of one of the existing configu-
2533 rations; see the main Makefile for supported names.
2535 Note: for some board special configuration names may exist; check if
2536 additional information is available from the board vendor; for
2537 instance, the TQM823L systems are available without (standard)
2538 or with LCD support. You can select such additional "features"
2539 when chosing the configuration, i. e.
2541 make TQM823L_config
2542 - will configure for a plain TQM823L, i. e. no LCD support
2544 make TQM823L_LCD_config
2545 - will configure for a TQM823L with U-Boot console on LCD
2547 etc.
2550 Finally, type "make all", and you should get some working U-Boot
2551 images ready for download to / installation on your system:
2553 - "u-boot.bin" is a raw binary image
2554 - "u-boot" is an image in ELF binary format
2555 - "u-boot.srec" is in Motorola S-Record format
2557 By default the build is performed locally and the objects are saved
2558 in the source directory. One of the two methods can be used to change
2559 this behavior and build U-Boot to some external directory:
2561 1. Add O= to the make command line invocations:
2563 make O=/tmp/build distclean
2564 make O=/tmp/build NAME_config
2565 make O=/tmp/build all
2567 2. Set environment variable BUILD_DIR to point to the desired location:
2569 export BUILD_DIR=/tmp/build
2570 make distclean
2571 make NAME_config
2572 make all
2574 Note that the command line "O=" setting overrides the BUILD_DIR environment
2575 variable.
2578 Please be aware that the Makefiles assume you are using GNU make, so
2579 for instance on NetBSD you might need to use "gmake" instead of
2580 native "make".
2583 If the system board that you have is not listed, then you will need
2584 to port U-Boot to your hardware platform. To do this, follow these
2585 steps:
2587 1. Add a new configuration option for your board to the toplevel
2588 "Makefile" and to the "MAKEALL" script, using the existing
2589 entries as examples. Note that here and at many other places
2590 boards and other names are listed in alphabetical sort order. Please
2591 keep this order.
2592 2. Create a new directory to hold your board specific code. Add any
2593 files you need. In your board directory, you will need at least
2594 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2595 3. Create a new configuration file "include/configs/<board>.h" for
2596 your board
2597 3. If you're porting U-Boot to a new CPU, then also create a new
2598 directory to hold your CPU specific code. Add any files you need.
2599 4. Run "make <board>_config" with your new name.
2600 5. Type "make", and you should get a working "u-boot.srec" file
2601 to be installed on your target system.
2602 6. Debug and solve any problems that might arise.
2603 [Of course, this last step is much harder than it sounds.]
2606 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2607 ==============================================================
2609 If you have modified U-Boot sources (for instance added a new board
2610 or support for new devices, a new CPU, etc.) you are expected to
2611 provide feedback to the other developers. The feedback normally takes
2612 the form of a "patch", i. e. a context diff against a certain (latest
2613 official or latest in the git repository) version of U-Boot sources.
2615 But before you submit such a patch, please verify that your modifi-
2616 cation did not break existing code. At least make sure that *ALL* of
2617 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2618 just run the "MAKEALL" script, which will configure and build U-Boot
2619 for ALL supported system. Be warned, this will take a while. You can
2620 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2621 environment variable to the script, i. e. to use the ELDK cross tools
2622 you can type
2624 CROSS_COMPILE=ppc_8xx- MAKEALL
2626 or to build on a native PowerPC system you can type
2628 CROSS_COMPILE=' ' MAKEALL
2630 When using the MAKEALL script, the default behaviour is to build
2631 U-Boot in the source directory. This location can be changed by
2632 setting the BUILD_DIR environment variable. Also, for each target
2633 built, the MAKEALL script saves two log files (<target>.ERR and
2634 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2635 location can be changed by setting the MAKEALL_LOGDIR environment
2636 variable. For example:
2638 export BUILD_DIR=/tmp/build
2639 export MAKEALL_LOGDIR=/tmp/log
2640 CROSS_COMPILE=ppc_8xx- MAKEALL
2642 With the above settings build objects are saved in the /tmp/build,
2643 log files are saved in the /tmp/log and the source tree remains clean
2644 during the whole build process.
2647 See also "U-Boot Porting Guide" below.
2650 Monitor Commands - Overview:
2651 ============================
2653 go - start application at address 'addr'
2654 run - run commands in an environment variable
2655 bootm - boot application image from memory
2656 bootp - boot image via network using BootP/TFTP protocol
2657 tftpboot- boot image via network using TFTP protocol
2658 and env variables "ipaddr" and "serverip"
2659 (and eventually "gatewayip")
2660 rarpboot- boot image via network using RARP/TFTP protocol
2661 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2662 loads - load S-Record file over serial line
2663 loadb - load binary file over serial line (kermit mode)
2664 md - memory display
2665 mm - memory modify (auto-incrementing)
2666 nm - memory modify (constant address)
2667 mw - memory write (fill)
2668 cp - memory copy
2669 cmp - memory compare
2670 crc32 - checksum calculation
2671 imd - i2c memory display
2672 imm - i2c memory modify (auto-incrementing)
2673 inm - i2c memory modify (constant address)
2674 imw - i2c memory write (fill)
2675 icrc32 - i2c checksum calculation
2676 iprobe - probe to discover valid I2C chip addresses
2677 iloop - infinite loop on address range
2678 isdram - print SDRAM configuration information
2679 sspi - SPI utility commands
2680 base - print or set address offset
2681 printenv- print environment variables
2682 setenv - set environment variables
2683 saveenv - save environment variables to persistent storage
2684 protect - enable or disable FLASH write protection
2685 erase - erase FLASH memory
2686 flinfo - print FLASH memory information
2687 bdinfo - print Board Info structure
2688 iminfo - print header information for application image
2689 coninfo - print console devices and informations
2690 ide - IDE sub-system
2691 loop - infinite loop on address range
2692 loopw - infinite write loop on address range
2693 mtest - simple RAM test
2694 icache - enable or disable instruction cache
2695 dcache - enable or disable data cache
2696 reset - Perform RESET of the CPU
2697 echo - echo args to console
2698 version - print monitor version
2699 help - print online help
2700 ? - alias for 'help'
2703 Monitor Commands - Detailed Description:
2704 ========================================
2706 TODO.
2708 For now: just type "help <command>".
2711 Environment Variables:
2712 ======================
2714 U-Boot supports user configuration using Environment Variables which
2715 can be made persistent by saving to Flash memory.
2717 Environment Variables are set using "setenv", printed using
2718 "printenv", and saved to Flash using "saveenv". Using "setenv"
2719 without a value can be used to delete a variable from the
2720 environment. As long as you don't save the environment you are
2721 working with an in-memory copy. In case the Flash area containing the
2722 environment is erased by accident, a default environment is provided.
2724 Some configuration options can be set using Environment Variables:
2726 baudrate - see CONFIG_BAUDRATE
2728 bootdelay - see CONFIG_BOOTDELAY
2730 bootcmd - see CONFIG_BOOTCOMMAND
2732 bootargs - Boot arguments when booting an RTOS image
2734 bootfile - Name of the image to load with TFTP
2736 autoload - if set to "no" (any string beginning with 'n'),
2737 "bootp" will just load perform a lookup of the
2738 configuration from the BOOTP server, but not try to
2739 load any image using TFTP
2741 autoscript - if set to "yes" commands like "loadb", "loady",
2742 "bootp", "tftpb", "rarpboot" and "nfs" will attempt
2743 to automatically run script images (by internally
2744 calling "autoscript").
2746 autoscript_uname - if script image is in a format (FIT) this
2747 variable is used to get script subimage unit name.
2749 autostart - if set to "yes", an image loaded using the "bootp",
2750 "rarpboot", "tftpboot" or "diskboot" commands will
2751 be automatically started (by internally calling
2752 "bootm")
2754 If set to "no", a standalone image passed to the
2755 "bootm" command will be copied to the load address
2756 (and eventually uncompressed), but NOT be started.
2757 This can be used to load and uncompress arbitrary
2758 data.
2760 i2cfast - (PPC405GP|PPC405EP only)
2761 if set to 'y' configures Linux I2C driver for fast
2762 mode (400kHZ). This environment variable is used in
2763 initialization code. So, for changes to be effective
2764 it must be saved and board must be reset.
2766 initrd_high - restrict positioning of initrd images:
2767 If this variable is not set, initrd images will be
2768 copied to the highest possible address in RAM; this
2769 is usually what you want since it allows for
2770 maximum initrd size. If for some reason you want to
2771 make sure that the initrd image is loaded below the
2772 CFG_BOOTMAPSZ limit, you can set this environment
2773 variable to a value of "no" or "off" or "0".
2774 Alternatively, you can set it to a maximum upper
2775 address to use (U-Boot will still check that it
2776 does not overwrite the U-Boot stack and data).
2778 For instance, when you have a system with 16 MB
2779 RAM, and want to reserve 4 MB from use by Linux,
2780 you can do this by adding "mem=12M" to the value of
2781 the "bootargs" variable. However, now you must make
2782 sure that the initrd image is placed in the first
2783 12 MB as well - this can be done with
2785 setenv initrd_high 00c00000
2787 If you set initrd_high to 0xFFFFFFFF, this is an
2788 indication to U-Boot that all addresses are legal
2789 for the Linux kernel, including addresses in flash
2790 memory. In this case U-Boot will NOT COPY the
2791 ramdisk at all. This may be useful to reduce the
2792 boot time on your system, but requires that this
2793 feature is supported by your Linux kernel.
2795 ipaddr - IP address; needed for tftpboot command
2797 loadaddr - Default load address for commands like "bootp",
2798 "rarpboot", "tftpboot", "loadb" or "diskboot"
2800 loads_echo - see CONFIG_LOADS_ECHO
2802 serverip - TFTP server IP address; needed for tftpboot command
2804 bootretry - see CONFIG_BOOT_RETRY_TIME
2806 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2808 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2810 ethprime - When CONFIG_NET_MULTI is enabled controls which
2811 interface is used first.
2813 ethact - When CONFIG_NET_MULTI is enabled controls which
2814 interface is currently active. For example you
2815 can do the following
2817 => setenv ethact FEC ETHERNET
2818 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2819 => setenv ethact SCC ETHERNET
2820 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2822 ethrotate - When set to "no" U-Boot does not go through all
2823 available network interfaces.
2824 It just stays at the currently selected interface.
2826 netretry - When set to "no" each network operation will
2827 either succeed or fail without retrying.
2828 When set to "once" the network operation will
2829 fail when all the available network interfaces
2830 are tried once without success.
2831 Useful on scripts which control the retry operation
2832 themselves.
2834 npe_ucode - see CONFIG_IXP4XX_NPE_EXT_UCOD
2835 if set load address for the npe microcode
2837 tftpsrcport - If this is set, the value is used for TFTP's
2838 UDP source port.
2840 tftpdstport - If this is set, the value is used for TFTP's UDP
2841 destination port instead of the Well Know Port 69.
2843 vlan - When set to a value < 4095 the traffic over
2844 ethernet is encapsulated/received over 802.1q
2845 VLAN tagged frames.
2847 The following environment variables may be used and automatically
2848 updated by the network boot commands ("bootp" and "rarpboot"),
2849 depending the information provided by your boot server:
2851 bootfile - see above
2852 dnsip - IP address of your Domain Name Server
2853 dnsip2 - IP address of your secondary Domain Name Server
2854 gatewayip - IP address of the Gateway (Router) to use
2855 hostname - Target hostname
2856 ipaddr - see above
2857 netmask - Subnet Mask
2858 rootpath - Pathname of the root filesystem on the NFS server
2859 serverip - see above
2862 There are two special Environment Variables:
2864 serial# - contains hardware identification information such
2865 as type string and/or serial number
2866 ethaddr - Ethernet address
2868 These variables can be set only once (usually during manufacturing of
2869 the board). U-Boot refuses to delete or overwrite these variables
2870 once they have been set once.
2873 Further special Environment Variables:
2875 ver - Contains the U-Boot version string as printed
2876 with the "version" command. This variable is
2877 readonly (see CONFIG_VERSION_VARIABLE).
2880 Please note that changes to some configuration parameters may take
2881 only effect after the next boot (yes, that's just like Windoze :-).
2884 Command Line Parsing:
2885 =====================
2887 There are two different command line parsers available with U-Boot:
2888 the old "simple" one, and the much more powerful "hush" shell:
2890 Old, simple command line parser:
2891 --------------------------------
2893 - supports environment variables (through setenv / saveenv commands)
2894 - several commands on one line, separated by ';'
2895 - variable substitution using "... ${name} ..." syntax
2896 - special characters ('$', ';') can be escaped by prefixing with '\',
2897 for example:
2898 setenv bootcmd bootm \${address}
2899 - You can also escape text by enclosing in single apostrophes, for example:
2900 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2902 Hush shell:
2903 -----------
2905 - similar to Bourne shell, with control structures like
2906 if...then...else...fi, for...do...done; while...do...done,
2907 until...do...done, ...
2908 - supports environment ("global") variables (through setenv / saveenv
2909 commands) and local shell variables (through standard shell syntax
2910 "name=value"); only environment variables can be used with "run"
2911 command
2913 General rules:
2914 --------------
2916 (1) If a command line (or an environment variable executed by a "run"
2917 command) contains several commands separated by semicolon, and
2918 one of these commands fails, then the remaining commands will be
2919 executed anyway.
2921 (2) If you execute several variables with one call to run (i. e.
2922 calling run with a list af variables as arguments), any failing
2923 command will cause "run" to terminate, i. e. the remaining
2924 variables are not executed.
2926 Note for Redundant Ethernet Interfaces:
2927 =======================================
2929 Some boards come with redundant ethernet interfaces; U-Boot supports
2930 such configurations and is capable of automatic selection of a
2931 "working" interface when needed. MAC assignment works as follows:
2933 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2934 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2935 "eth1addr" (=>eth1), "eth2addr", ...
2937 If the network interface stores some valid MAC address (for instance
2938 in SROM), this is used as default address if there is NO correspon-
2939 ding setting in the environment; if the corresponding environment
2940 variable is set, this overrides the settings in the card; that means:
2942 o If the SROM has a valid MAC address, and there is no address in the
2943 environment, the SROM's address is used.
2945 o If there is no valid address in the SROM, and a definition in the
2946 environment exists, then the value from the environment variable is
2947 used.
2949 o If both the SROM and the environment contain a MAC address, and
2950 both addresses are the same, this MAC address is used.
2952 o If both the SROM and the environment contain a MAC address, and the
2953 addresses differ, the value from the environment is used and a
2954 warning is printed.
2956 o If neither SROM nor the environment contain a MAC address, an error
2957 is raised.
2960 Image Formats:
2961 ==============
2963 U-Boot is capable of booting (and performing other auxiliary operations on)
2964 images in two formats:
2966 New uImage format (FIT)
2967 -----------------------
2969 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
2970 to Flattened Device Tree). It allows the use of images with multiple
2971 components (several kernels, ramdisks, etc.), with contents protected by
2972 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
2975 Old uImage format
2976 -----------------
2978 Old image format is based on binary files which can be basically anything,
2979 preceded by a special header; see the definitions in include/image.h for
2980 details; basically, the header defines the following image properties:
2982 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2983 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2984 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2985 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2986 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
2987 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2988 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
2989 * Compression Type (uncompressed, gzip, bzip2)
2990 * Load Address
2991 * Entry Point
2992 * Image Name
2993 * Image Timestamp
2995 The header is marked by a special Magic Number, and both the header
2996 and the data portions of the image are secured against corruption by
2997 CRC32 checksums.
3000 Linux Support:
3001 ==============
3003 Although U-Boot should support any OS or standalone application
3004 easily, the main focus has always been on Linux during the design of
3005 U-Boot.
3007 U-Boot includes many features that so far have been part of some
3008 special "boot loader" code within the Linux kernel. Also, any
3009 "initrd" images to be used are no longer part of one big Linux image;
3010 instead, kernel and "initrd" are separate images. This implementation
3011 serves several purposes:
3013 - the same features can be used for other OS or standalone
3014 applications (for instance: using compressed images to reduce the
3015 Flash memory footprint)
3017 - it becomes much easier to port new Linux kernel versions because
3018 lots of low-level, hardware dependent stuff are done by U-Boot
3020 - the same Linux kernel image can now be used with different "initrd"
3021 images; of course this also means that different kernel images can
3022 be run with the same "initrd". This makes testing easier (you don't
3023 have to build a new "zImage.initrd" Linux image when you just
3024 change a file in your "initrd"). Also, a field-upgrade of the
3025 software is easier now.
3028 Linux HOWTO:
3029 ============
3031 Porting Linux to U-Boot based systems:
3032 ---------------------------------------
3034 U-Boot cannot save you from doing all the necessary modifications to
3035 configure the Linux device drivers for use with your target hardware
3036 (no, we don't intend to provide a full virtual machine interface to
3037 Linux :-).
3039 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3041 Just make sure your machine specific header file (for instance
3042 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3043 Information structure as we define in include/u-boot.h, and make
3044 sure that your definition of IMAP_ADDR uses the same value as your
3045 U-Boot configuration in CFG_IMMR.
3048 Configuring the Linux kernel:
3049 -----------------------------
3051 No specific requirements for U-Boot. Make sure you have some root
3052 device (initial ramdisk, NFS) for your target system.
3055 Building a Linux Image:
3056 -----------------------
3058 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3059 not used. If you use recent kernel source, a new build target
3060 "uImage" will exist which automatically builds an image usable by
3061 U-Boot. Most older kernels also have support for a "pImage" target,
3062 which was introduced for our predecessor project PPCBoot and uses a
3063 100% compatible format.
3065 Example:
3067 make TQM850L_config
3068 make oldconfig
3069 make dep
3070 make uImage
3072 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3073 encapsulate a compressed Linux kernel image with header information,
3074 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3076 * build a standard "vmlinux" kernel image (in ELF binary format):
3078 * convert the kernel into a raw binary image:
3080 ${CROSS_COMPILE}-objcopy -O binary \
3081 -R .note -R .comment \
3082 -S vmlinux linux.bin
3084 * compress the binary image:
3086 gzip -9 linux.bin
3088 * package compressed binary image for U-Boot:
3090 mkimage -A ppc -O linux -T kernel -C gzip \
3091 -a 0 -e 0 -n "Linux Kernel Image" \
3092 -d linux.bin.gz uImage
3095 The "mkimage" tool can also be used to create ramdisk images for use
3096 with U-Boot, either separated from the Linux kernel image, or
3097 combined into one file. "mkimage" encapsulates the images with a 64
3098 byte header containing information about target architecture,
3099 operating system, image type, compression method, entry points, time
3100 stamp, CRC32 checksums, etc.
3102 "mkimage" can be called in two ways: to verify existing images and
3103 print the header information, or to build new images.
3105 In the first form (with "-l" option) mkimage lists the information
3106 contained in the header of an existing U-Boot image; this includes
3107 checksum verification:
3109 tools/mkimage -l image
3110 -l ==> list image header information
3112 The second form (with "-d" option) is used to build a U-Boot image
3113 from a "data file" which is used as image payload:
3115 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3116 -n name -d data_file image
3117 -A ==> set architecture to 'arch'
3118 -O ==> set operating system to 'os'
3119 -T ==> set image type to 'type'
3120 -C ==> set compression type 'comp'
3121 -a ==> set load address to 'addr' (hex)
3122 -e ==> set entry point to 'ep' (hex)
3123 -n ==> set image name to 'name'
3124 -d ==> use image data from 'datafile'
3126 Right now, all Linux kernels for PowerPC systems use the same load
3127 address (0x00000000), but the entry point address depends on the
3128 kernel version:
3130 - 2.2.x kernels have the entry point at 0x0000000C,
3131 - 2.3.x and later kernels have the entry point at 0x00000000.
3133 So a typical call to build a U-Boot image would read:
3135 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3136 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3137 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3138 > examples/uImage.TQM850L
3139 Image Name: 2.4.4 kernel for TQM850L
3140 Created: Wed Jul 19 02:34:59 2000
3141 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3142 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3143 Load Address: 0x00000000
3144 Entry Point: 0x00000000
3146 To verify the contents of the image (or check for corruption):
3148 -> tools/mkimage -l examples/uImage.TQM850L
3149 Image Name: 2.4.4 kernel for TQM850L
3150 Created: Wed Jul 19 02:34:59 2000
3151 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3152 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3153 Load Address: 0x00000000
3154 Entry Point: 0x00000000
3156 NOTE: for embedded systems where boot time is critical you can trade
3157 speed for memory and install an UNCOMPRESSED image instead: this
3158 needs more space in Flash, but boots much faster since it does not
3159 need to be uncompressed:
3161 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3162 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3163 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3164 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3165 > examples/uImage.TQM850L-uncompressed
3166 Image Name: 2.4.4 kernel for TQM850L
3167 Created: Wed Jul 19 02:34:59 2000
3168 Image Type: PowerPC Linux Kernel Image (uncompressed)
3169 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3170 Load Address: 0x00000000
3171 Entry Point: 0x00000000
3174 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3175 when your kernel is intended to use an initial ramdisk:
3177 -> tools/mkimage -n 'Simple Ramdisk Image' \
3178 > -A ppc -O linux -T ramdisk -C gzip \
3179 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3180 Image Name: Simple Ramdisk Image
3181 Created: Wed Jan 12 14:01:50 2000
3182 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3183 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3184 Load Address: 0x00000000
3185 Entry Point: 0x00000000
3188 Installing a Linux Image:
3189 -------------------------
3191 To downloading a U-Boot image over the serial (console) interface,
3192 you must convert the image to S-Record format:
3194 objcopy -I binary -O srec examples/image examples/image.srec
3196 The 'objcopy' does not understand the information in the U-Boot
3197 image header, so the resulting S-Record file will be relative to
3198 address 0x00000000. To load it to a given address, you need to
3199 specify the target address as 'offset' parameter with the 'loads'
3200 command.
3202 Example: install the image to address 0x40100000 (which on the
3203 TQM8xxL is in the first Flash bank):
3205 => erase 40100000 401FFFFF
3207 .......... done
3208 Erased 8 sectors
3210 => loads 40100000
3211 ## Ready for S-Record download ...
3212 ~>examples/image.srec
3213 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3214 ...
3215 15989 15990 15991 15992
3216 [file transfer complete]
3217 [connected]
3218 ## Start Addr = 0x00000000
3221 You can check the success of the download using the 'iminfo' command;
3222 this includes a checksum verification so you can be sure no data
3223 corruption happened:
3225 => imi 40100000
3227 ## Checking Image at 40100000 ...
3228 Image Name: 2.2.13 for initrd on TQM850L
3229 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3230 Data Size: 335725 Bytes = 327 kB = 0 MB
3231 Load Address: 00000000
3232 Entry Point: 0000000c
3233 Verifying Checksum ... OK
3236 Boot Linux:
3237 -----------
3239 The "bootm" command is used to boot an application that is stored in
3240 memory (RAM or Flash). In case of a Linux kernel image, the contents
3241 of the "bootargs" environment variable is passed to the kernel as
3242 parameters. You can check and modify this variable using the
3243 "printenv" and "setenv" commands:
3246 => printenv bootargs
3247 bootargs=root=/dev/ram
3249 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3251 => printenv bootargs
3252 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3254 => bootm 40020000
3255 ## Booting Linux kernel at 40020000 ...
3256 Image Name: 2.2.13 for NFS on TQM850L
3257 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3258 Data Size: 381681 Bytes = 372 kB = 0 MB
3259 Load Address: 00000000
3260 Entry Point: 0000000c
3261 Verifying Checksum ... OK
3262 Uncompressing Kernel Image ... OK
3263 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
3264 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3265 time_init: decrementer frequency = 187500000/60
3266 Calibrating delay loop... 49.77 BogoMIPS
3267 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3268 ...
3270 If you want to boot a Linux kernel with initial ram disk, you pass
3271 the memory addresses of both the kernel and the initrd image (PPBCOOT
3272 format!) to the "bootm" command:
3274 => imi 40100000 40200000
3276 ## Checking Image at 40100000 ...
3277 Image Name: 2.2.13 for initrd on TQM850L
3278 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3279 Data Size: 335725 Bytes = 327 kB = 0 MB
3280 Load Address: 00000000
3281 Entry Point: 0000000c
3282 Verifying Checksum ... OK
3284 ## Checking Image at 40200000 ...
3285 Image Name: Simple Ramdisk Image
3286 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3287 Data Size: 566530 Bytes = 553 kB = 0 MB
3288 Load Address: 00000000
3289 Entry Point: 00000000
3290 Verifying Checksum ... OK
3292 => bootm 40100000 40200000
3293 ## Booting Linux kernel at 40100000 ...
3294 Image Name: 2.2.13 for initrd on TQM850L
3295 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3296 Data Size: 335725 Bytes = 327 kB = 0 MB
3297 Load Address: 00000000
3298 Entry Point: 0000000c
3299 Verifying Checksum ... OK
3300 Uncompressing Kernel Image ... OK
3301 ## Loading RAMDisk Image at 40200000 ...
3302 Image Name: Simple Ramdisk Image
3303 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3304 Data Size: 566530 Bytes = 553 kB = 0 MB
3305 Load Address: 00000000
3306 Entry Point: 00000000
3307 Verifying Checksum ... OK
3308 Loading Ramdisk ... OK
3309 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
3310 Boot arguments: root=/dev/ram
3311 time_init: decrementer frequency = 187500000/60
3312 Calibrating delay loop... 49.77 BogoMIPS
3313 ...
3314 RAMDISK: Compressed image found at block 0
3315 VFS: Mounted root (ext2 filesystem).
3317 bash#
3319 Boot Linux and pass a flat device tree:
3320 -----------
3322 First, U-Boot must be compiled with the appropriate defines. See the section
3323 titled "Linux Kernel Interface" above for a more in depth explanation. The
3324 following is an example of how to start a kernel and pass an updated
3325 flat device tree:
3327 => print oftaddr
3328 oftaddr=0x300000
3329 => print oft
3330 oft=oftrees/mpc8540ads.dtb
3331 => tftp $oftaddr $oft
3332 Speed: 1000, full duplex
3333 Using TSEC0 device
3334 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3335 Filename 'oftrees/mpc8540ads.dtb'.
3336 Load address: 0x300000
3337 Loading: #
3338 done
3339 Bytes transferred = 4106 (100a hex)
3340 => tftp $loadaddr $bootfile
3341 Speed: 1000, full duplex
3342 Using TSEC0 device
3343 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3344 Filename 'uImage'.
3345 Load address: 0x200000
3346 Loading:############
3347 done
3348 Bytes transferred = 1029407 (fb51f hex)
3349 => print loadaddr
3350 loadaddr=200000
3351 => print oftaddr
3352 oftaddr=0x300000
3353 => bootm $loadaddr - $oftaddr
3354 ## Booting image at 00200000 ...
3355 Image Name: Linux-2.6.17-dirty
3356 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3357 Data Size: 1029343 Bytes = 1005.2 kB
3358 Load Address: 00000000
3359 Entry Point: 00000000
3360 Verifying Checksum ... OK
3361 Uncompressing Kernel Image ... OK
3362 Booting using flat device tree at 0x300000
3363 Using MPC85xx ADS machine description
3364 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3365 [snip]
3368 More About U-Boot Image Types:
3369 ------------------------------
3371 U-Boot supports the following image types:
3373 "Standalone Programs" are directly runnable in the environment
3374 provided by U-Boot; it is expected that (if they behave
3375 well) you can continue to work in U-Boot after return from
3376 the Standalone Program.
3377 "OS Kernel Images" are usually images of some Embedded OS which
3378 will take over control completely. Usually these programs
3379 will install their own set of exception handlers, device
3380 drivers, set up the MMU, etc. - this means, that you cannot
3381 expect to re-enter U-Boot except by resetting the CPU.
3382 "RAMDisk Images" are more or less just data blocks, and their
3383 parameters (address, size) are passed to an OS kernel that is
3384 being started.
3385 "Multi-File Images" contain several images, typically an OS
3386 (Linux) kernel image and one or more data images like
3387 RAMDisks. This construct is useful for instance when you want
3388 to boot over the network using BOOTP etc., where the boot
3389 server provides just a single image file, but you want to get
3390 for instance an OS kernel and a RAMDisk image.
3392 "Multi-File Images" start with a list of image sizes, each
3393 image size (in bytes) specified by an "uint32_t" in network
3394 byte order. This list is terminated by an "(uint32_t)0".
3395 Immediately after the terminating 0 follow the images, one by
3396 one, all aligned on "uint32_t" boundaries (size rounded up to
3397 a multiple of 4 bytes).
3399 "Firmware Images" are binary images containing firmware (like
3400 U-Boot or FPGA images) which usually will be programmed to
3401 flash memory.
3403 "Script files" are command sequences that will be executed by
3404 U-Boot's command interpreter; this feature is especially
3405 useful when you configure U-Boot to use a real shell (hush)
3406 as command interpreter.
3409 Standalone HOWTO:
3410 =================
3412 One of the features of U-Boot is that you can dynamically load and
3413 run "standalone" applications, which can use some resources of
3414 U-Boot like console I/O functions or interrupt services.
3416 Two simple examples are included with the sources:
3418 "Hello World" Demo:
3419 -------------------
3421 'examples/hello_world.c' contains a small "Hello World" Demo
3422 application; it is automatically compiled when you build U-Boot.
3423 It's configured to run at address 0x00040004, so you can play with it
3424 like that:
3426 => loads
3427 ## Ready for S-Record download ...
3428 ~>examples/hello_world.srec
3429 1 2 3 4 5 6 7 8 9 10 11 ...
3430 [file transfer complete]
3431 [connected]
3432 ## Start Addr = 0x00040004
3434 => go 40004 Hello World! This is a test.
3435 ## Starting application at 0x00040004 ...
3436 Hello World
3437 argc = 7
3438 argv[0] = "40004"
3439 argv[1] = "Hello"
3440 argv[2] = "World!"
3441 argv[3] = "This"
3442 argv[4] = "is"
3443 argv[5] = "a"
3444 argv[6] = "test."
3445 argv[7] = "<NULL>"
3446 Hit any key to exit ...
3448 ## Application terminated, rc = 0x0
3450 Another example, which demonstrates how to register a CPM interrupt
3451 handler with the U-Boot code, can be found in 'examples/timer.c'.
3452 Here, a CPM timer is set up to generate an interrupt every second.
3453 The interrupt service routine is trivial, just printing a '.'
3454 character, but this is just a demo program. The application can be
3455 controlled by the following keys:
3457 ? - print current values og the CPM Timer registers
3458 b - enable interrupts and start timer
3459 e - stop timer and disable interrupts
3460 q - quit application
3462 => loads
3463 ## Ready for S-Record download ...
3464 ~>examples/timer.srec
3465 1 2 3 4 5 6 7 8 9 10 11 ...
3466 [file transfer complete]
3467 [connected]
3468 ## Start Addr = 0x00040004
3470 => go 40004
3471 ## Starting application at 0x00040004 ...
3472 TIMERS=0xfff00980
3473 Using timer 1
3474 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3476 Hit 'b':
3477 [q, b, e, ?] Set interval 1000000 us
3478 Enabling timer
3479 Hit '?':
3480 [q, b, e, ?] ........
3481 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3482 Hit '?':
3483 [q, b, e, ?] .
3484 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3485 Hit '?':
3486 [q, b, e, ?] .
3487 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3488 Hit '?':
3489 [q, b, e, ?] .
3490 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3491 Hit 'e':
3492 [q, b, e, ?] ...Stopping timer
3493 Hit 'q':
3494 [q, b, e, ?] ## Application terminated, rc = 0x0
3497 Minicom warning:
3498 ================
3500 Over time, many people have reported problems when trying to use the
3501 "minicom" terminal emulation program for serial download. I (wd)
3502 consider minicom to be broken, and recommend not to use it. Under
3503 Unix, I recommend to use C-Kermit for general purpose use (and
3504 especially for kermit binary protocol download ("loadb" command), and
3505 use "cu" for S-Record download ("loads" command).
3507 Nevertheless, if you absolutely want to use it try adding this
3508 configuration to your "File transfer protocols" section:
3510 Name Program Name U/D FullScr IO-Red. Multi
3511 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3512 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3515 NetBSD Notes:
3516 =============
3518 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3519 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3521 Building requires a cross environment; it is known to work on
3522 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3523 need gmake since the Makefiles are not compatible with BSD make).
3524 Note that the cross-powerpc package does not install include files;
3525 attempting to build U-Boot will fail because <machine/ansi.h> is
3526 missing. This file has to be installed and patched manually:
3528 # cd /usr/pkg/cross/powerpc-netbsd/include
3529 # mkdir powerpc
3530 # ln -s powerpc machine
3531 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3532 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3534 Native builds *don't* work due to incompatibilities between native
3535 and U-Boot include files.
3537 Booting assumes that (the first part of) the image booted is a
3538 stage-2 loader which in turn loads and then invokes the kernel
3539 proper. Loader sources will eventually appear in the NetBSD source
3540 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3541 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3544 Implementation Internals:
3545 =========================
3547 The following is not intended to be a complete description of every
3548 implementation detail. However, it should help to understand the
3549 inner workings of U-Boot and make it easier to port it to custom
3550 hardware.
3553 Initial Stack, Global Data:
3554 ---------------------------
3556 The implementation of U-Boot is complicated by the fact that U-Boot
3557 starts running out of ROM (flash memory), usually without access to
3558 system RAM (because the memory controller is not initialized yet).
3559 This means that we don't have writable Data or BSS segments, and BSS
3560 is not initialized as zero. To be able to get a C environment working
3561 at all, we have to allocate at least a minimal stack. Implementation
3562 options for this are defined and restricted by the CPU used: Some CPU
3563 models provide on-chip memory (like the IMMR area on MPC8xx and
3564 MPC826x processors), on others (parts of) the data cache can be
3565 locked as (mis-) used as memory, etc.
3567 Chris Hallinan posted a good summary of these issues to the
3568 u-boot-users mailing list:
3570 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3571 From: "Chris Hallinan" <clh@net1plus.com>
3572 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3573 ...
3575 Correct me if I'm wrong, folks, but the way I understand it
3576 is this: Using DCACHE as initial RAM for Stack, etc, does not
3577 require any physical RAM backing up the cache. The cleverness
3578 is that the cache is being used as a temporary supply of
3579 necessary storage before the SDRAM controller is setup. It's
3580 beyond the scope of this list to expain the details, but you
3581 can see how this works by studying the cache architecture and
3582 operation in the architecture and processor-specific manuals.
3584 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3585 is another option for the system designer to use as an
3586 initial stack/ram area prior to SDRAM being available. Either
3587 option should work for you. Using CS 4 should be fine if your
3588 board designers haven't used it for something that would
3589 cause you grief during the initial boot! It is frequently not
3590 used.
3592 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
3593 with your processor/board/system design. The default value
3594 you will find in any recent u-boot distribution in
3595 walnut.h should work for you. I'd set it to a value larger
3596 than your SDRAM module. If you have a 64MB SDRAM module, set
3597 it above 400_0000. Just make sure your board has no resources
3598 that are supposed to respond to that address! That code in
3599 start.S has been around a while and should work as is when
3600 you get the config right.
3602 -Chris Hallinan
3603 DS4.COM, Inc.
3605 It is essential to remember this, since it has some impact on the C
3606 code for the initialization procedures:
3608 * Initialized global data (data segment) is read-only. Do not attempt
3609 to write it.
3611 * Do not use any unitialized global data (or implicitely initialized
3612 as zero data - BSS segment) at all - this is undefined, initiali-
3613 zation is performed later (when relocating to RAM).
3615 * Stack space is very limited. Avoid big data buffers or things like
3616 that.
3618 Having only the stack as writable memory limits means we cannot use
3619 normal global data to share information beween the code. But it
3620 turned out that the implementation of U-Boot can be greatly
3621 simplified by making a global data structure (gd_t) available to all
3622 functions. We could pass a pointer to this data as argument to _all_
3623 functions, but this would bloat the code. Instead we use a feature of
3624 the GCC compiler (Global Register Variables) to share the data: we
3625 place a pointer (gd) to the global data into a register which we
3626 reserve for this purpose.
3628 When choosing a register for such a purpose we are restricted by the
3629 relevant (E)ABI specifications for the current architecture, and by
3630 GCC's implementation.
3632 For PowerPC, the following registers have specific use:
3633 R1: stack pointer
3634 R2: reserved for system use
3635 R3-R4: parameter passing and return values
3636 R5-R10: parameter passing
3637 R13: small data area pointer
3638 R30: GOT pointer
3639 R31: frame pointer
3641 (U-Boot also uses R14 as internal GOT pointer.)
3643 ==> U-Boot will use R2 to hold a pointer to the global data
3645 Note: on PPC, we could use a static initializer (since the
3646 address of the global data structure is known at compile time),
3647 but it turned out that reserving a register results in somewhat
3648 smaller code - although the code savings are not that big (on
3649 average for all boards 752 bytes for the whole U-Boot image,
3650 624 text + 127 data).
3652 On Blackfin, the normal C ABI (except for P5) is followed as documented here:
3653 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3655 ==> U-Boot will use P5 to hold a pointer to the global data
3657 On ARM, the following registers are used:
3659 R0: function argument word/integer result
3660 R1-R3: function argument word
3661 R9: GOT pointer
3662 R10: stack limit (used only if stack checking if enabled)
3663 R11: argument (frame) pointer
3664 R12: temporary workspace
3665 R13: stack pointer
3666 R14: link register
3667 R15: program counter
3669 ==> U-Boot will use R8 to hold a pointer to the global data
3671 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3672 or current versions of GCC may "optimize" the code too much.
3674 Memory Management:
3675 ------------------
3677 U-Boot runs in system state and uses physical addresses, i.e. the
3678 MMU is not used either for address mapping nor for memory protection.
3680 The available memory is mapped to fixed addresses using the memory
3681 controller. In this process, a contiguous block is formed for each
3682 memory type (Flash, SDRAM, SRAM), even when it consists of several
3683 physical memory banks.
3685 U-Boot is installed in the first 128 kB of the first Flash bank (on
3686 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3687 booting and sizing and initializing DRAM, the code relocates itself
3688 to the upper end of DRAM. Immediately below the U-Boot code some
3689 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
3690 configuration setting]. Below that, a structure with global Board
3691 Info data is placed, followed by the stack (growing downward).
3693 Additionally, some exception handler code is copied to the low 8 kB
3694 of DRAM (0x00000000 ... 0x00001FFF).
3696 So a typical memory configuration with 16 MB of DRAM could look like
3697 this:
3699 0x0000 0000 Exception Vector code
3700 :
3701 0x0000 1FFF
3702 0x0000 2000 Free for Application Use
3703 :
3704 :
3706 :
3707 :
3708 0x00FB FF20 Monitor Stack (Growing downward)
3709 0x00FB FFAC Board Info Data and permanent copy of global data
3710 0x00FC 0000 Malloc Arena
3711 :
3712 0x00FD FFFF
3713 0x00FE 0000 RAM Copy of Monitor Code
3714 ... eventually: LCD or video framebuffer
3715 ... eventually: pRAM (Protected RAM - unchanged by reset)
3716 0x00FF FFFF [End of RAM]
3719 System Initialization:
3720 ----------------------
3722 In the reset configuration, U-Boot starts at the reset entry point
3723 (on most PowerPC systens at address 0x00000100). Because of the reset
3724 configuration for CS0# this is a mirror of the onboard Flash memory.
3725 To be able to re-map memory U-Boot then jumps to its link address.
3726 To be able to implement the initialization code in C, a (small!)
3727 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3728 which provide such a feature like MPC8xx or MPC8260), or in a locked
3729 part of the data cache. After that, U-Boot initializes the CPU core,
3730 the caches and the SIU.
3732 Next, all (potentially) available memory banks are mapped using a
3733 preliminary mapping. For example, we put them on 512 MB boundaries
3734 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3735 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3736 programmed for SDRAM access. Using the temporary configuration, a
3737 simple memory test is run that determines the size of the SDRAM
3738 banks.
3740 When there is more than one SDRAM bank, and the banks are of
3741 different size, the largest is mapped first. For equal size, the first
3742 bank (CS2#) is mapped first. The first mapping is always for address
3743 0x00000000, with any additional banks following immediately to create
3744 contiguous memory starting from 0.
3746 Then, the monitor installs itself at the upper end of the SDRAM area
3747 and allocates memory for use by malloc() and for the global Board
3748 Info data; also, the exception vector code is copied to the low RAM
3749 pages, and the final stack is set up.
3751 Only after this relocation will you have a "normal" C environment;
3752 until that you are restricted in several ways, mostly because you are
3753 running from ROM, and because the code will have to be relocated to a
3754 new address in RAM.
3757 U-Boot Porting Guide:
3758 ----------------------
3760 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3761 list, October 2002]
3764 int main (int argc, char *argv[])
3765 {
3766 sighandler_t no_more_time;
3768 signal (SIGALRM, no_more_time);
3769 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3771 if (available_money > available_manpower) {
3772 pay consultant to port U-Boot;
3773 return 0;
3774 }
3776 Download latest U-Boot source;
3778 Subscribe to u-boot-users mailing list;
3780 if (clueless) {
3781 email ("Hi, I am new to U-Boot, how do I get started?");
3782 }
3784 while (learning) {
3785 Read the README file in the top level directory;
3786 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3787 Read the source, Luke;
3788 }
3790 if (available_money > toLocalCurrency ($2500)) {
3791 Buy a BDI2000;
3792 } else {
3793 Add a lot of aggravation and time;
3794 }
3796 Create your own board support subdirectory;
3798 Create your own board config file;
3800 while (!running) {
3801 do {
3802 Add / modify source code;
3803 } until (compiles);
3804 Debug;
3805 if (clueless)
3806 email ("Hi, I am having problems...");
3807 }
3808 Send patch file to Wolfgang;
3810 return 0;
3811 }
3813 void no_more_time (int sig)
3814 {
3815 hire_a_guru();
3816 }
3819 Coding Standards:
3820 -----------------
3822 All contributions to U-Boot should conform to the Linux kernel
3823 coding style; see the file "Documentation/CodingStyle" and the script
3824 "scripts/Lindent" in your Linux kernel source directory. In sources
3825 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
3826 spaces before parameters to function calls) is actually used.
3828 Source files originating from a different project (for example the
3829 MTD subsystem) are generally exempt from these guidelines and are not
3830 reformated to ease subsequent migration to newer versions of those
3831 sources.
3833 Please note that U-Boot is implemented in C (and to some small parts in
3834 Assembler); no C++ is used, so please do not use C++ style comments (//)
3835 in your code.
3837 Please also stick to the following formatting rules:
3838 - remove any trailing white space
3839 - use TAB characters for indentation, not spaces
3840 - make sure NOT to use DOS '\r\n' line feeds
3841 - do not add more than 2 empty lines to source files
3842 - do not add trailing empty lines to source files
3844 Submissions which do not conform to the standards may be returned
3845 with a request to reformat the changes.
3848 Submitting Patches:
3849 -------------------
3851 Since the number of patches for U-Boot is growing, we need to
3852 establish some rules. Submissions which do not conform to these rules
3853 may be rejected, even when they contain important and valuable stuff.
3855 Patches shall be sent to the u-boot-users mailing list.
3857 Please see http://www.denx.de/wiki/UBoot/Patches for details.
3859 When you send a patch, please include the following information with
3860 it:
3862 * For bug fixes: a description of the bug and how your patch fixes
3863 this bug. Please try to include a way of demonstrating that the
3864 patch actually fixes something.
3866 * For new features: a description of the feature and your
3867 implementation.
3869 * A CHANGELOG entry as plaintext (separate from the patch)
3871 * For major contributions, your entry to the CREDITS file
3873 * When you add support for a new board, don't forget to add this
3874 board to the MAKEALL script, too.
3876 * If your patch adds new configuration options, don't forget to
3877 document these in the README file.
3879 * The patch itself. If you are using git (which is *strongly*
3880 recommended) you can easily generate the patch using the
3881 "git-format-patch". If you then use "git-send-email" to send it to
3882 the U-Boot mailing list, you will avoid most of the common problems
3883 with some other mail clients.
3885 If you cannot use git, use "diff -purN OLD NEW". If your version of
3886 diff does not support these options, then get the latest version of
3887 GNU diff.
3889 The current directory when running this command shall be the parent
3890 directory of the U-Boot source tree (i. e. please make sure that
3891 your patch includes sufficient directory information for the
3892 affected files).
3894 We prefer patches as plain text. MIME attachments are discouraged,
3895 and compressed attachments must not be used.
3897 * If one logical set of modifications affects or creates several
3898 files, all these changes shall be submitted in a SINGLE patch file.
3900 * Changesets that contain different, unrelated modifications shall be
3901 submitted as SEPARATE patches, one patch per changeset.
3904 Notes:
3906 * Before sending the patch, run the MAKEALL script on your patched
3907 source tree and make sure that no errors or warnings are reported
3908 for any of the boards.
3910 * Keep your modifications to the necessary minimum: A patch
3911 containing several unrelated changes or arbitrary reformats will be
3912 returned with a request to re-formatting / split it.
3914 * If you modify existing code, make sure that your new code does not
3915 add to the memory footprint of the code ;-) Small is beautiful!
3916 When adding new features, these should compile conditionally only
3917 (using #ifdef), and the resulting code with the new feature
3918 disabled must not need more memory than the old code without your
3919 modification.
3921 * Remember that there is a size limit of 40 kB per message on the
3922 u-boot-users mailing list. Bigger patches will be moderated. If
3923 they are reasonable and not bigger than 100 kB, they will be
3924 acknowledged. Even bigger patches should be avoided.