2 # (C) Copyright 2000 - 2004
3 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 # See file CREDITS for list of people who contributed to this
8 # This program is free software; you can redistribute it and/or
9 # modify it under the terms of the GNU General Public License as
10 # published by the Free Software Foundation; either version 2 of
11 # the License, or (at your option) any later version.
13 # This program is distributed in the hope that it will be useful,
14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 # GNU General Public License for more details.
18 # You should have received a copy of the GNU General Public License
19 # along with this program; if not, write to the Free Software
20 # Foundation, Inc., 59 Temple Place, Suite 330, Boston,
27 This directory contains the source code for U-Boot, a boot loader for
28 Embedded boards based on PowerPC and ARM processors, which can be
29 installed in a boot ROM and used to initialize and test the hardware
30 or to download and run application code.
32 The development of U-Boot is closely related to Linux: some parts of
33 the source code originate in the Linux source tree, we have some
34 header files in common, and special provision has been made to
35 support booting of Linux images.
37 Some attention has been paid to make this software easily
38 configurable and extendable. For instance, all monitor commands are
39 implemented with the same call interface, so that it's very easy to
40 add new commands. Also, instead of permanently adding rarely used
41 code (for instance hardware test utilities) to the monitor, you can
42 load and run it dynamically.
48 In general, all boards for which a configuration option exists in the
49 Makefile have been tested to some extent and can be considered
50 "working". In fact, many of them are used in production systems.
52 In case of problems see the CHANGELOG and CREDITS files to find out
53 who contributed the specific port.
59 In case you have questions about, problems with or contributions for
60 U-Boot you should send a message to the U-Boot mailing list at
61 <u-boot-users@lists.sourceforge.net>. There is also an archive of
62 previous traffic on the mailing list - please search the archive
63 before asking FAQ's. Please see
64 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
70 - start from 8xxrom sources
71 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
73 - make it easier to add custom boards
74 - make it possible to add other [PowerPC] CPUs
75 - extend functions, especially:
76 * Provide extended interface to Linux boot loader
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80 - create ARMBoot project (http://sourceforge.net/projects/armboot)
81 - add other CPU families (starting with ARM)
82 - create U-Boot project (http://sourceforge.net/projects/u-boot)
88 The "official" name of this project is "Das U-Boot". The spelling
89 "U-Boot" shall be used in all written text (documentation, comments
90 in source files etc.). Example:
92 This is the README file for the U-Boot project.
94 File names etc. shall be based on the string "u-boot". Examples:
96 include/asm-ppc/u-boot.h
98 #include <asm/u-boot.h>
100 Variable names, preprocessor constants etc. shall be either based on
101 the string "u_boot" or on "U_BOOT". Example:
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
110 U-Boot uses a 3 level version number containing a version, a
111 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
112 sub-version "34", and patchlevel "4".
114 The patchlevel is used to indicate certain stages of development
115 between released versions, i. e. officially released versions of
116 U-Boot will always have a patchlevel of "0".
122 - board Board dependent files
123 - common Misc architecture independent functions
124 - cpu CPU specific files
125 - 74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
126 - arm720t Files specific to ARM 720 CPUs
127 - arm920t Files specific to ARM 920 CPUs
128 - arm925t Files specific to ARM 925 CPUs
129 - arm926ejs Files specific to ARM 926 CPUs
130 - at91rm9200 Files specific to Atmel AT91RM9200 CPUs
131 - i386 Files specific to i386 CPUs
132 - ixp Files specific to Intel XScale IXP CPUs
133 - mcf52x2 Files specific to Motorola ColdFire MCF52x2 CPUs
134 - mips Files specific to MIPS CPUs
135 - mpc5xx Files specific to Motorola MPC5xx CPUs
136 - mpc5xxx Files specific to Motorola MPC5xxx CPUs
137 - mpc8xx Files specific to Motorola MPC8xx CPUs
138 - mpc824x Files specific to Motorola MPC824x CPUs
139 - mpc8260 Files specific to Motorola MPC8260 CPUs
140 - mpc85xx Files specific to Motorola MPC85xx CPUs
141 - nios Files specific to Altera NIOS CPUs
142 - ppc4xx Files specific to IBM PowerPC 4xx CPUs
143 - pxa Files specific to Intel XScale PXA CPUs
144 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
145 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
146 - disk Code for disk drive partition handling
147 - doc Documentation (don't expect too much)
148 - drivers Commonly used device drivers
149 - dtt Digital Thermometer and Thermostat drivers
150 - examples Example code for standalone applications, etc.
151 - include Header Files
152 - lib_arm Files generic to ARM architecture
153 - lib_generic Files generic to all architectures
154 - lib_i386 Files generic to i386 architecture
155 - lib_m68k Files generic to m68k architecture
156 - lib_mips Files generic to MIPS architecture
157 - lib_nios Files generic to NIOS architecture
158 - lib_ppc Files generic to PowerPC architecture
159 - net Networking code
160 - post Power On Self Test
161 - rtc Real Time Clock drivers
162 - tools Tools to build S-Record or U-Boot images, etc.
164 Software Configuration:
165 =======================
167 Configuration is usually done using C preprocessor defines; the
168 rationale behind that is to avoid dead code whenever possible.
170 There are two classes of configuration variables:
172 * Configuration _OPTIONS_:
173 These are selectable by the user and have names beginning with
176 * Configuration _SETTINGS_:
177 These depend on the hardware etc. and should not be meddled with if
178 you don't know what you're doing; they have names beginning with
181 Later we will add a configuration tool - probably similar to or even
182 identical to what's used for the Linux kernel. Right now, we have to
183 do the configuration by hand, which means creating some symbolic
184 links and editing some configuration files. We use the TQM8xxL boards
188 Selection of Processor Architecture and Board Type:
189 ---------------------------------------------------
191 For all supported boards there are ready-to-use default
192 configurations available; just type "make <board_name>_config".
194 Example: For a TQM823L module type:
199 For the Cogent platform, you need to specify the cpu type as well;
200 e.g. "make cogent_mpc8xx_config". And also configure the cogent
201 directory according to the instructions in cogent/README.
204 Configuration Options:
205 ----------------------
207 Configuration depends on the combination of board and CPU type; all
208 such information is kept in a configuration file
209 "include/configs/<board_name>.h".
211 Example: For a TQM823L module, all configuration settings are in
212 "include/configs/TQM823L.h".
215 Many of the options are named exactly as the corresponding Linux
216 kernel configuration options. The intention is to make it easier to
217 build a config tool - later.
220 The following options need to be configured:
222 - CPU Type: Define exactly one of
226 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
228 or CONFIG_MPC824X, CONFIG_MPC8260
244 - Board Type: Define exactly one of
246 PowerPC based boards:
247 ---------------------
249 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
250 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
251 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
252 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
253 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
254 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
255 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
256 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
257 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
258 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
259 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
260 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
261 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
262 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
263 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
264 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
265 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
266 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
267 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
268 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
269 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
270 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
271 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
272 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
273 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
274 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
275 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
276 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
277 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
278 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
279 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI,
280 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900,
281 CONFIG_MPC8540ADS, CONFIG_MPC8560ADS, CONFIG_QS850,
282 CONFIG_QS823, CONFIG_QS860T, CONFIG_DB64360,
283 CONFIG_DB64460, CONFIG_DUET_ADS CONFIG_NETTA
289 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
290 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
291 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610,
292 CONFIG_H2_OMAP1610, CONFIG_SHANNON, CONFIG_SMDK2400,
293 CONFIG_SMDK2410, CONFIG_TRAB, CONFIG_VCMA9,
297 - CPU Module Type: (if CONFIG_COGENT is defined)
298 Define exactly one of
300 --- FIXME --- not tested yet:
301 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
302 CONFIG_CMA287_23, CONFIG_CMA287_50
304 - Motherboard Type: (if CONFIG_COGENT is defined)
305 Define exactly one of
306 CONFIG_CMA101, CONFIG_CMA102
308 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
309 Define one or more of
312 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
313 Define one or more of
314 CONFIG_LCD_HEARTBEAT - update a character position on
315 the lcd display every second with
318 - Board flavour: (if CONFIG_MPC8260ADS is defined)
321 CFG_8260ADS - original MPC8260ADS
322 CFG_8266ADS - MPC8266ADS
323 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
324 CFG_8272ADS - MPC8272ADS
326 - MPC824X Family Member (if CONFIG_MPC824X is defined)
327 Define exactly one of
328 CONFIG_MPC8240, CONFIG_MPC8245
330 - 8xx CPU Options: (if using an MPC8xx cpu)
331 Define one or more of
332 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work
333 e.g. if there is no 32KHz
334 reference PIT/RTC clock
336 - 859/866 CPU options: (if using a MPC859 or MPC866 CPU):
340 CFG_866_CPUCLK_DEFAULT
341 See doc/README.MPC866
345 Define this to measure the actual CPU clock instead
346 of relying on the correctness of the configured
347 values. Mostly useful for board bringup to make sure
348 the PLL is locked at the intended frequency. Note
349 that this requires a (stable) reference clock (32 kHz
352 - Linux Kernel Interface:
355 U-Boot stores all clock information in Hz
356 internally. For binary compatibility with older Linux
357 kernels (which expect the clocks passed in the
358 bd_info data to be in MHz) the environment variable
359 "clocks_in_mhz" can be defined so that U-Boot
360 converts clock data to MHZ before passing it to the
362 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
363 "clocks_in_mhz=1" is automatically included in the
366 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
368 When transfering memsize parameter to linux, some versions
369 expect it to be in bytes, others in MB.
370 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
373 Depending on board, define exactly one serial port
374 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
375 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
376 console by defining CONFIG_8xx_CONS_NONE
378 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
379 port routines must be defined elsewhere
380 (i.e. serial_init(), serial_getc(), ...)
383 Enables console device for a color framebuffer. Needs following
384 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
385 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
387 VIDEO_HW_RECTFILL graphic chip supports
390 VIDEO_HW_BITBLT graphic chip supports
391 bit-blit (cf. smiLynxEM)
392 VIDEO_VISIBLE_COLS visible pixel columns
394 VIDEO_VISIBLE_ROWS visible pixel rows
395 VIDEO_PIXEL_SIZE bytes per pixel
396 VIDEO_DATA_FORMAT graphic data format
397 (0-5, cf. cfb_console.c)
398 VIDEO_FB_ADRS framebuffer address
399 VIDEO_KBD_INIT_FCT keyboard int fct
400 (i.e. i8042_kbd_init())
401 VIDEO_TSTC_FCT test char fct
403 VIDEO_GETC_FCT get char fct
405 CONFIG_CONSOLE_CURSOR cursor drawing on/off
406 (requires blink timer
408 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
409 CONFIG_CONSOLE_TIME display time/date info in
411 (requires CFG_CMD_DATE)
412 CONFIG_VIDEO_LOGO display Linux logo in
414 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
415 linux_logo.h for logo.
416 Requires CONFIG_VIDEO_LOGO
417 CONFIG_CONSOLE_EXTRA_INFO
418 addional board info beside
421 When CONFIG_CFB_CONSOLE is defined, video console is
422 default i/o. Serial console can be forced with
423 environment 'console=serial'.
425 When CONFIG_SILENT_CONSOLE is defined, all console
426 messages (by U-Boot and Linux!) can be silenced with
427 the "silent" environment variable. See
428 doc/README.silent for more information.
431 CONFIG_BAUDRATE - in bps
432 Select one of the baudrates listed in
433 CFG_BAUDRATE_TABLE, see below.
434 CFG_BRGCLK_PRESCALE, baudrate prescale
436 - Interrupt driven serial port input:
437 CONFIG_SERIAL_SOFTWARE_FIFO
440 Use an interrupt handler for receiving data on the
441 serial port. It also enables using hardware handshake
442 (RTS/CTS) and UART's built-in FIFO. Set the number of
443 bytes the interrupt driven input buffer should have.
445 Leave undefined to disable this feature, including
446 disable the buffer and hardware handshake.
448 - Console UART Number:
452 If defined internal UART1 (and not UART0) is used
453 as default U-Boot console.
455 - Boot Delay: CONFIG_BOOTDELAY - in seconds
456 Delay before automatically booting the default image;
457 set to -1 to disable autoboot.
459 See doc/README.autoboot for these options that
460 work with CONFIG_BOOTDELAY. None are required.
461 CONFIG_BOOT_RETRY_TIME
462 CONFIG_BOOT_RETRY_MIN
463 CONFIG_AUTOBOOT_KEYED
464 CONFIG_AUTOBOOT_PROMPT
465 CONFIG_AUTOBOOT_DELAY_STR
466 CONFIG_AUTOBOOT_STOP_STR
467 CONFIG_AUTOBOOT_DELAY_STR2
468 CONFIG_AUTOBOOT_STOP_STR2
469 CONFIG_ZERO_BOOTDELAY_CHECK
470 CONFIG_RESET_TO_RETRY
474 Only needed when CONFIG_BOOTDELAY is enabled;
475 define a command string that is automatically executed
476 when no character is read on the console interface
477 within "Boot Delay" after reset.
480 This can be used to pass arguments to the bootm
481 command. The value of CONFIG_BOOTARGS goes into the
482 environment value "bootargs".
484 CONFIG_RAMBOOT and CONFIG_NFSBOOT
485 The value of these goes into the environment as
486 "ramboot" and "nfsboot" respectively, and can be used
487 as a convenience, when switching between booting from
493 When this option is #defined, the existence of the
494 environment variable "preboot" will be checked
495 immediately before starting the CONFIG_BOOTDELAY
496 countdown and/or running the auto-boot command resp.
497 entering interactive mode.
499 This feature is especially useful when "preboot" is
500 automatically generated or modified. For an example
501 see the LWMON board specific code: here "preboot" is
502 modified when the user holds down a certain
503 combination of keys on the (special) keyboard when
506 - Serial Download Echo Mode:
508 If defined to 1, all characters received during a
509 serial download (using the "loads" command) are
510 echoed back. This might be needed by some terminal
511 emulations (like "cu"), but may as well just take
512 time on others. This setting #define's the initial
513 value of the "loads_echo" environment variable.
515 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
517 Select one of the baudrates listed in
518 CFG_BAUDRATE_TABLE, see below.
522 Most monitor functions can be selected (or
523 de-selected) by adjusting the definition of
524 CONFIG_COMMANDS; to select individual functions,
525 #define CONFIG_COMMANDS by "OR"ing any of the
528 #define enables commands:
529 -------------------------
530 CFG_CMD_ASKENV * ask for env variable
531 CFG_CMD_AUTOSCRIPT Autoscript Support
533 CFG_CMD_BEDBUG Include BedBug Debugger
534 CFG_CMD_BMP * BMP support
536 CFG_CMD_CACHE icache, dcache
537 CFG_CMD_CONSOLE coninfo
538 CFG_CMD_DATE * support for RTC, date/time...
539 CFG_CMD_DHCP DHCP support
540 CFG_CMD_DIAG * Diagnostics
541 CFG_CMD_DOC * Disk-On-Chip Support
542 CFG_CMD_DTT Digital Therm and Thermostat
543 CFG_CMD_ECHO * echo arguments
544 CFG_CMD_EEPROM * EEPROM read/write support
545 CFG_CMD_ELF bootelf, bootvx
547 CFG_CMD_FDC * Floppy Disk Support
548 CFG_CMD_FAT FAT partition support
549 CFG_CMD_FDOS * Dos diskette Support
550 CFG_CMD_FLASH flinfo, erase, protect
551 CFG_CMD_FPGA FPGA device initialization support
552 CFG_CMD_HWFLOW * RTS/CTS hw flow control
553 CFG_CMD_I2C * I2C serial bus support
554 CFG_CMD_IDE * IDE harddisk support
556 CFG_CMD_IMLS List all found images
557 CFG_CMD_IMMAP * IMMR dump support
558 CFG_CMD_IRQ * irqinfo
559 CFG_CMD_ITEST * Integer/string test of 2 values
560 CFG_CMD_JFFS2 * JFFS2 Support
564 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
566 CFG_CMD_MISC Misc functions like sleep etc
567 CFG_CMD_MMC MMC memory mapped support
568 CFG_CMD_MII MII utility commands
569 CFG_CMD_NAND * NAND support
570 CFG_CMD_NET bootp, tftpboot, rarpboot
571 CFG_CMD_PCI * pciinfo
572 CFG_CMD_PCMCIA * PCMCIA support
573 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
574 CFG_CMD_PORTIO * Port I/O
575 CFG_CMD_REGINFO * Register dump
576 CFG_CMD_RUN run command in env variable
577 CFG_CMD_SAVES save S record dump
578 CFG_CMD_SCSI * SCSI Support
579 CFG_CMD_SDRAM * print SDRAM configuration information
580 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
581 CFG_CMD_SPI * SPI serial bus support
582 CFG_CMD_USB * USB support
583 CFG_CMD_VFD * VFD support (TRAB)
584 CFG_CMD_BSP * Board SPecific functions
585 -----------------------------------------------
588 CFG_CMD_DFL Default configuration; at the moment
589 this is includes all commands, except
590 the ones marked with "*" in the list
593 If you don't define CONFIG_COMMANDS it defaults to
594 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
595 override the default settings in the respective
598 EXAMPLE: If you want all functions except of network
599 support you can write:
601 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
604 Note: Don't enable the "icache" and "dcache" commands
605 (configuration option CFG_CMD_CACHE) unless you know
606 what you (and your U-Boot users) are doing. Data
607 cache cannot be enabled on systems like the 8xx or
608 8260 (where accesses to the IMMR region must be
609 uncached), and it cannot be disabled on all other
610 systems where we (mis-) use the data cache to hold an
611 initial stack and some data.
614 XXX - this list needs to get updated!
618 If this variable is defined, it enables watchdog
619 support. There must be support in the platform specific
620 code for a watchdog. For the 8xx and 8260 CPUs, the
621 SIU Watchdog feature is enabled in the SYPCR
625 CONFIG_VERSION_VARIABLE
626 If this variable is defined, an environment variable
627 named "ver" is created by U-Boot showing the U-Boot
628 version as printed by the "version" command.
629 This variable is readonly.
633 When CFG_CMD_DATE is selected, the type of the RTC
634 has to be selected, too. Define exactly one of the
637 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
638 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
639 CONFIG_RTC_MC146818 - use MC146818 RTC
640 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
641 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
642 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
643 CONFIG_RTC_DS164x - use Dallas DS164x RTC
645 Note that if the RTC uses I2C, then the I2C interface
646 must also be configured. See I2C Support, below.
650 When CONFIG_TIMESTAMP is selected, the timestamp
651 (date and time) of an image is printed by image
652 commands like bootm or iminfo. This option is
653 automatically enabled when you select CFG_CMD_DATE .
656 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
657 and/or CONFIG_ISO_PARTITION
659 If IDE or SCSI support is enabled (CFG_CMD_IDE or
660 CFG_CMD_SCSI) you must configure support for at least
661 one partition type as well.
664 CONFIG_IDE_RESET_ROUTINE - this is defined in several
665 board configurations files but used nowhere!
667 CONFIG_IDE_RESET - is this is defined, IDE Reset will
668 be performed by calling the function
669 ide_set_reset(int reset)
670 which has to be defined in a board specific file
675 Set this to enable ATAPI support.
680 Set this to enable support for disks larger than 137GB
681 Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
682 Whithout these , LBA48 support uses 32bit variables and will 'only'
683 support disks up to 2.1TB.
686 When enabled, makes the IDE subsystem use 64bit sector addresses.
690 At the moment only there is only support for the
691 SYM53C8XX SCSI controller; define
692 CONFIG_SCSI_SYM53C8XX to enable it.
694 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
695 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
696 CFG_SCSI_MAX_LUN] can be adjusted to define the
697 maximum numbers of LUNs, SCSI ID's and target
699 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
701 - NETWORK Support (PCI):
703 Support for Intel 8254x gigabit chips.
706 Support for Intel 82557/82559/82559ER chips.
707 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
708 write routine for first time initialisation.
711 Support for Digital 2114x chips.
712 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
713 modem chip initialisation (KS8761/QS6611).
716 Support for National dp83815 chips.
719 Support for National dp8382[01] gigabit chips.
721 - NETWORK Support (other):
723 CONFIG_DRIVER_LAN91C96
724 Support for SMSC's LAN91C96 chips.
727 Define this to hold the physical address
728 of the LAN91C96's I/O space
730 CONFIG_LAN91C96_USE_32_BIT
731 Define this to enable 32 bit addressing
734 At the moment only the UHCI host controller is
735 supported (PIP405, MIP405, MPC5200); define
736 CONFIG_USB_UHCI to enable it.
737 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
738 end define CONFIG_USB_STORAGE to enable the USB
741 Supported are USB Keyboards and USB Floppy drives
743 MPC5200 USB requires additional defines:
745 for 528 MHz Clock: 0x0001bbbb
747 for differential drivers: 0x00001000
748 for single ended drivers: 0x00005000
752 The MMC controller on the Intel PXA is supported. To
753 enable this define CONFIG_MMC. The MMC can be
754 accessed from the boot prompt by mapping the device
755 to physical memory similar to flash. Command line is
756 enabled with CFG_CMD_MMC. The MMC driver also works with
757 the FAT fs. This is enabled with CFG_CMD_FAT.
762 Define this to enable standard (PC-Style) keyboard
766 Standard PC keyboard driver with US (is default) and
767 GERMAN key layout (switch via environment 'keymap=de') support.
768 Export function i8042_kbd_init, i8042_tstc and i8042_getc
769 for cfb_console. Supports cursor blinking.
774 Define this to enable video support (for output to
779 Enable Chips & Technologies 69000 Video chip
781 CONFIG_VIDEO_SMI_LYNXEM
782 Enable Silicon Motion SMI 712/710/810 Video chip. The
783 video output is selected via environment 'videoout'
784 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
787 For the CT69000 and SMI_LYNXEM drivers, videomode is
788 selected via environment 'videomode'. Two diferent ways
790 - "videomode=num" 'num' is a standard LiLo mode numbers.
791 Following standard modes are supported (* is default):
793 Colors 640x480 800x600 1024x768 1152x864 1280x1024
794 -------------+---------------------------------------------
795 8 bits | 0x301* 0x303 0x305 0x161 0x307
796 15 bits | 0x310 0x313 0x316 0x162 0x319
797 16 bits | 0x311 0x314 0x317 0x163 0x31A
798 24 bits | 0x312 0x315 0x318 ? 0x31B
799 -------------+---------------------------------------------
800 (i.e. setenv videomode 317; saveenv; reset;)
802 - "videomode=bootargs" all the video parameters are parsed
803 from the bootargs. (See drivers/videomodes.c)
806 CONFIG_VIDEO_SED13806
807 Enable Epson SED13806 driver. This driver supports 8bpp
808 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
809 or CONFIG_VIDEO_SED13806_16BPP
814 Define this to enable a custom keyboard support.
815 This simply calls drv_keyboard_init() which must be
816 defined in your board-specific files.
817 The only board using this so far is RBC823.
819 - LCD Support: CONFIG_LCD
821 Define this to enable LCD support (for output to LCD
822 display); also select one of the supported displays
823 by defining one of these:
825 CONFIG_NEC_NL6448AC33:
827 NEC NL6448AC33-18. Active, color, single scan.
829 CONFIG_NEC_NL6448BC20
831 NEC NL6448BC20-08. 6.5", 640x480.
832 Active, color, single scan.
834 CONFIG_NEC_NL6448BC33_54
836 NEC NL6448BC33-54. 10.4", 640x480.
837 Active, color, single scan.
841 Sharp 320x240. Active, color, single scan.
842 It isn't 16x9, and I am not sure what it is.
844 CONFIG_SHARP_LQ64D341
846 Sharp LQ64D341 display, 640x480.
847 Active, color, single scan.
851 HLD1045 display, 640x480.
852 Active, color, single scan.
856 Optrex CBL50840-2 NF-FW 99 22 M5
858 Hitachi LMG6912RPFC-00T
862 320x240. Black & white.
864 Normally display is black on white background; define
865 CFG_WHITE_ON_BLACK to get it inverted.
867 - Splash Screen Support: CONFIG_SPLASH_SCREEN
869 If this option is set, the environment is checked for
870 a variable "splashimage". If found, the usual display
871 of logo, copyright and system information on the LCD
872 is supressed and the BMP image at the address
873 specified in "splashimage" is loaded instead. The
874 console is redirected to the "nulldev", too. This
875 allows for a "silent" boot where a splash screen is
876 loaded very quickly after power-on.
878 - Compression support:
881 If this option is set, support for bzip2 compressed
882 images is included. If not, only uncompressed and gzip
883 compressed images are supported.
885 NOTE: the bzip2 algorithm requires a lot of RAM, so
886 the malloc area (as defined by CFG_MALLOC_LEN) should
894 Define a default value for ethernet address to use
895 for the respective ethernet interface, in case this
896 is not determined automatically.
901 Define a default value for the IP address to use for
902 the default ethernet interface, in case this is not
903 determined through e.g. bootp.
908 Defines a default value for theIP address of a TFTP
909 server to contact when using the "tftboot" command.
911 - BOOTP Recovery Mode:
912 CONFIG_BOOTP_RANDOM_DELAY
914 If you have many targets in a network that try to
915 boot using BOOTP, you may want to avoid that all
916 systems send out BOOTP requests at precisely the same
917 moment (which would happen for instance at recovery
918 from a power failure, when all systems will try to
919 boot, thus flooding the BOOTP server. Defining
920 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
921 inserted before sending out BOOTP requests. The
922 following delays are insterted then:
924 1st BOOTP request: delay 0 ... 1 sec
925 2nd BOOTP request: delay 0 ... 2 sec
926 3rd BOOTP request: delay 0 ... 4 sec
928 BOOTP requests: delay 0 ... 8 sec
930 - DHCP Advanced Options:
933 You can fine tune the DHCP functionality by adding
934 these flags to the CONFIG_BOOTP_MASK define:
936 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
937 serverip from a DHCP server, it is possible that more
938 than one DNS serverip is offered to the client.
939 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
940 serverip will be stored in the additional environment
941 variable "dnsip2". The first DNS serverip is always
942 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
943 is added to the CONFIG_BOOTP_MASK.
945 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
946 to do a dynamic update of a DNS server. To do this, they
947 need the hostname of the DHCP requester.
948 If CONFIG_BOOP_SEND_HOSTNAME is added to the
949 CONFIG_BOOTP_MASK, the content of the "hostname"
950 environment variable is passed as option 12 to
953 - Status LED: CONFIG_STATUS_LED
955 Several configurations allow to display the current
956 status using a LED. For instance, the LED will blink
957 fast while running U-Boot code, stop blinking as
958 soon as a reply to a BOOTP request was received, and
959 start blinking slow once the Linux kernel is running
960 (supported by a status LED driver in the Linux
961 kernel). Defining CONFIG_STATUS_LED enables this
964 - CAN Support: CONFIG_CAN_DRIVER
966 Defining CONFIG_CAN_DRIVER enables CAN driver support
967 on those systems that support this (optional)
968 feature, like the TQM8xxL modules.
970 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
972 These enable I2C serial bus commands. Defining either of
973 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
974 include the appropriate I2C driver for the selected cpu.
976 This will allow you to use i2c commands at the u-boot
977 command line (as long as you set CFG_CMD_I2C in
978 CONFIG_COMMANDS) and communicate with i2c based realtime
979 clock chips. See common/cmd_i2c.c for a description of the
980 command line interface.
982 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
984 CONFIG_SOFT_I2C configures u-boot to use a software (aka
985 bit-banging) driver instead of CPM or similar hardware
988 There are several other quantities that must also be
989 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
991 In both cases you will need to define CFG_I2C_SPEED
992 to be the frequency (in Hz) at which you wish your i2c bus
993 to run and CFG_I2C_SLAVE to be the address of this node (ie
994 the cpu's i2c node address).
996 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
997 sets the cpu up as a master node and so its address should
998 therefore be cleared to 0 (See, eg, MPC823e User's Manual
999 p.16-473). So, set CFG_I2C_SLAVE to 0.
1001 That's all that's required for CONFIG_HARD_I2C.
1003 If you use the software i2c interface (CONFIG_SOFT_I2C)
1004 then the following macros need to be defined (examples are
1005 from include/configs/lwmon.h):
1009 (Optional). Any commands necessary to enable the I2C
1010 controller or configure ports.
1012 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1016 (Only for MPC8260 CPU). The I/O port to use (the code
1017 assumes both bits are on the same port). Valid values
1018 are 0..3 for ports A..D.
1022 The code necessary to make the I2C data line active
1023 (driven). If the data line is open collector, this
1026 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1030 The code necessary to make the I2C data line tri-stated
1031 (inactive). If the data line is open collector, this
1034 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1038 Code that returns TRUE if the I2C data line is high,
1041 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1045 If <bit> is TRUE, sets the I2C data line high. If it
1046 is FALSE, it clears it (low).
1048 eg: #define I2C_SDA(bit) \
1049 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1050 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1054 If <bit> is TRUE, sets the I2C clock line high. If it
1055 is FALSE, it clears it (low).
1057 eg: #define I2C_SCL(bit) \
1058 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1059 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1063 This delay is invoked four times per clock cycle so this
1064 controls the rate of data transfer. The data rate thus
1065 is 1 / (I2C_DELAY * 4). Often defined to be something
1068 #define I2C_DELAY udelay(2)
1072 When a board is reset during an i2c bus transfer
1073 chips might think that the current transfer is still
1074 in progress. On some boards it is possible to access
1075 the i2c SCLK line directly, either by using the
1076 processor pin as a GPIO or by having a second pin
1077 connected to the bus. If this option is defined a
1078 custom i2c_init_board() routine in boards/xxx/board.c
1079 is run early in the boot sequence.
1081 - SPI Support: CONFIG_SPI
1083 Enables SPI driver (so far only tested with
1084 SPI EEPROM, also an instance works with Crystal A/D and
1085 D/As on the SACSng board)
1089 Enables extended (16-bit) SPI EEPROM addressing.
1090 (symmetrical to CONFIG_I2C_X)
1094 Enables a software (bit-bang) SPI driver rather than
1095 using hardware support. This is a general purpose
1096 driver that only requires three general I/O port pins
1097 (two outputs, one input) to function. If this is
1098 defined, the board configuration must define several
1099 SPI configuration items (port pins to use, etc). For
1100 an example, see include/configs/sacsng.h.
1102 - FPGA Support: CONFIG_FPGA_COUNT
1104 Specify the number of FPGA devices to support.
1108 Used to specify the types of FPGA devices. For example,
1109 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1111 CFG_FPGA_PROG_FEEDBACK
1113 Enable printing of hash marks during FPGA configuration.
1117 Enable checks on FPGA configuration interface busy
1118 status by the configuration function. This option
1119 will require a board or device specific function to
1124 If defined, a function that provides delays in the FPGA
1125 configuration driver.
1127 CFG_FPGA_CHECK_CTRLC
1128 Allow Control-C to interrupt FPGA configuration
1130 CFG_FPGA_CHECK_ERROR
1132 Check for configuration errors during FPGA bitfile
1133 loading. For example, abort during Virtex II
1134 configuration if the INIT_B line goes low (which
1135 indicated a CRC error).
1139 Maximum time to wait for the INIT_B line to deassert
1140 after PROB_B has been deasserted during a Virtex II
1141 FPGA configuration sequence. The default time is 500
1146 Maximum time to wait for BUSY to deassert during
1147 Virtex II FPGA configuration. The default is 5 mS.
1149 CFG_FPGA_WAIT_CONFIG
1151 Time to wait after FPGA configuration. The default is
1154 - Configuration Management:
1157 If defined, this string will be added to the U-Boot
1158 version information (U_BOOT_VERSION)
1160 - Vendor Parameter Protection:
1162 U-Boot considers the values of the environment
1163 variables "serial#" (Board Serial Number) and
1164 "ethaddr" (Ethernet Address) to be parameters that
1165 are set once by the board vendor / manufacturer, and
1166 protects these variables from casual modification by
1167 the user. Once set, these variables are read-only,
1168 and write or delete attempts are rejected. You can
1169 change this behviour:
1171 If CONFIG_ENV_OVERWRITE is #defined in your config
1172 file, the write protection for vendor parameters is
1173 completely disabled. Anybody can change or delete
1176 Alternatively, if you #define _both_ CONFIG_ETHADDR
1177 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1178 ethernet address is installed in the environment,
1179 which can be changed exactly ONCE by the user. [The
1180 serial# is unaffected by this, i. e. it remains
1186 Define this variable to enable the reservation of
1187 "protected RAM", i. e. RAM which is not overwritten
1188 by U-Boot. Define CONFIG_PRAM to hold the number of
1189 kB you want to reserve for pRAM. You can overwrite
1190 this default value by defining an environment
1191 variable "pram" to the number of kB you want to
1192 reserve. Note that the board info structure will
1193 still show the full amount of RAM. If pRAM is
1194 reserved, a new environment variable "mem" will
1195 automatically be defined to hold the amount of
1196 remaining RAM in a form that can be passed as boot
1197 argument to Linux, for instance like that:
1199 setenv bootargs ... mem=\$(mem)
1202 This way you can tell Linux not to use this memory,
1203 either, which results in a memory region that will
1204 not be affected by reboots.
1206 *WARNING* If your board configuration uses automatic
1207 detection of the RAM size, you must make sure that
1208 this memory test is non-destructive. So far, the
1209 following board configurations are known to be
1212 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1213 HERMES, IP860, RPXlite, LWMON, LANTEC,
1214 PCU_E, FLAGADM, TQM8260
1219 Define this variable to stop the system in case of a
1220 fatal error, so that you have to reset it manually.
1221 This is probably NOT a good idea for an embedded
1222 system where you want to system to reboot
1223 automatically as fast as possible, but it may be
1224 useful during development since you can try to debug
1225 the conditions that lead to the situation.
1227 CONFIG_NET_RETRY_COUNT
1229 This variable defines the number of retries for
1230 network operations like ARP, RARP, TFTP, or BOOTP
1231 before giving up the operation. If not defined, a
1232 default value of 5 is used.
1234 - Command Interpreter:
1237 Enable auto completion of commands using TAB.
1241 Define this variable to enable the "hush" shell (from
1242 Busybox) as command line interpreter, thus enabling
1243 powerful command line syntax like
1244 if...then...else...fi conditionals or `&&' and '||'
1245 constructs ("shell scripts").
1247 If undefined, you get the old, much simpler behaviour
1248 with a somewhat smaller memory footprint.
1253 This defines the secondary prompt string, which is
1254 printed when the command interpreter needs more input
1255 to complete a command. Usually "> ".
1259 In the current implementation, the local variables
1260 space and global environment variables space are
1261 separated. Local variables are those you define by
1262 simply typing `name=value'. To access a local
1263 variable later on, you have write `$name' or
1264 `${name}'; to execute the contents of a variable
1265 directly type `$name' at the command prompt.
1267 Global environment variables are those you use
1268 setenv/printenv to work with. To run a command stored
1269 in such a variable, you need to use the run command,
1270 and you must not use the '$' sign to access them.
1272 To store commands and special characters in a
1273 variable, please use double quotation marks
1274 surrounding the whole text of the variable, instead
1275 of the backslashes before semicolons and special
1278 - Default Environment:
1279 CONFIG_EXTRA_ENV_SETTINGS
1281 Define this to contain any number of null terminated
1282 strings (variable = value pairs) that will be part of
1283 the default environment compiled into the boot image.
1285 For example, place something like this in your
1286 board's config file:
1288 #define CONFIG_EXTRA_ENV_SETTINGS \
1292 Warning: This method is based on knowledge about the
1293 internal format how the environment is stored by the
1294 U-Boot code. This is NOT an official, exported
1295 interface! Although it is unlikely that this format
1296 will change soon, there is no guarantee either.
1297 You better know what you are doing here.
1299 Note: overly (ab)use of the default environment is
1300 discouraged. Make sure to check other ways to preset
1301 the environment like the autoscript function or the
1304 - DataFlash Support:
1305 CONFIG_HAS_DATAFLASH
1307 Defining this option enables DataFlash features and
1308 allows to read/write in Dataflash via the standard
1311 - SystemACE Support:
1314 Adding this option adds support for Xilinx SystemACE
1315 chips attached via some sort of local bus. The address
1316 of the chip must alsh be defined in the
1317 CFG_SYSTEMACE_BASE macro. For example:
1319 #define CONFIG_SYSTEMACE
1320 #define CFG_SYSTEMACE_BASE 0xf0000000
1322 When SystemACE support is added, the "ace" device type
1323 becomes available to the fat commands, i.e. fatls.
1325 - Show boot progress:
1326 CONFIG_SHOW_BOOT_PROGRESS
1328 Defining this option allows to add some board-
1329 specific code (calling a user-provided function
1330 "show_boot_progress(int)") that enables you to show
1331 the system's boot progress on some display (for
1332 example, some LED's) on your board. At the moment,
1333 the following checkpoints are implemented:
1336 1 common/cmd_bootm.c before attempting to boot an image
1337 -1 common/cmd_bootm.c Image header has bad magic number
1338 2 common/cmd_bootm.c Image header has correct magic number
1339 -2 common/cmd_bootm.c Image header has bad checksum
1340 3 common/cmd_bootm.c Image header has correct checksum
1341 -3 common/cmd_bootm.c Image data has bad checksum
1342 4 common/cmd_bootm.c Image data has correct checksum
1343 -4 common/cmd_bootm.c Image is for unsupported architecture
1344 5 common/cmd_bootm.c Architecture check OK
1345 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1346 6 common/cmd_bootm.c Image Type check OK
1347 -6 common/cmd_bootm.c gunzip uncompression error
1348 -7 common/cmd_bootm.c Unimplemented compression type
1349 7 common/cmd_bootm.c Uncompression OK
1350 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1351 8 common/cmd_bootm.c Image Type check OK
1352 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1353 9 common/cmd_bootm.c Start initial ramdisk verification
1354 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1355 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1356 10 common/cmd_bootm.c Ramdisk header is OK
1357 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1358 11 common/cmd_bootm.c Ramdisk data has correct checksum
1359 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1360 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1361 13 common/cmd_bootm.c Start multifile image verification
1362 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1363 15 common/cmd_bootm.c All preparation done, transferring control to OS
1365 -30 lib_ppc/board.c Fatal error, hang the system
1366 -31 post/post.c POST test failed, detected by post_output_backlog()
1367 -32 post/post.c POST test failed, detected by post_run_single()
1369 -1 common/cmd_doc.c Bad usage of "doc" command
1370 -1 common/cmd_doc.c No boot device
1371 -1 common/cmd_doc.c Unknown Chip ID on boot device
1372 -1 common/cmd_doc.c Read Error on boot device
1373 -1 common/cmd_doc.c Image header has bad magic number
1375 -1 common/cmd_ide.c Bad usage of "ide" command
1376 -1 common/cmd_ide.c No boot device
1377 -1 common/cmd_ide.c Unknown boot device
1378 -1 common/cmd_ide.c Unknown partition table
1379 -1 common/cmd_ide.c Invalid partition type
1380 -1 common/cmd_ide.c Read Error on boot device
1381 -1 common/cmd_ide.c Image header has bad magic number
1383 -1 common/cmd_nand.c Bad usage of "nand" command
1384 -1 common/cmd_nand.c No boot device
1385 -1 common/cmd_nand.c Unknown Chip ID on boot device
1386 -1 common/cmd_nand.c Read Error on boot device
1387 -1 common/cmd_nand.c Image header has bad magic number
1389 -1 common/env_common.c Environment has a bad CRC, using default
1395 [so far only for SMDK2400 and TRAB boards]
1397 - Modem support endable:
1398 CONFIG_MODEM_SUPPORT
1400 - RTS/CTS Flow control enable:
1403 - Modem debug support:
1404 CONFIG_MODEM_SUPPORT_DEBUG
1406 Enables debugging stuff (char screen[1024], dbg())
1407 for modem support. Useful only with BDI2000.
1409 - Interrupt support (PPC):
1411 There are common interrupt_init() and timer_interrupt()
1412 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1413 for cpu specific initialization. interrupt_init_cpu()
1414 should set decrementer_count to appropriate value. If
1415 cpu resets decrementer automatically after interrupt
1416 (ppc4xx) it should set decrementer_count to zero.
1417 timer_interrupt() calls timer_interrupt_cpu() for cpu
1418 specific handling. If board has watchdog / status_led
1419 / other_activity_monitor it works automatically from
1420 general timer_interrupt().
1424 In the target system modem support is enabled when a
1425 specific key (key combination) is pressed during
1426 power-on. Otherwise U-Boot will boot normally
1427 (autoboot). The key_pressed() fuction is called from
1428 board_init(). Currently key_pressed() is a dummy
1429 function, returning 1 and thus enabling modem
1432 If there are no modem init strings in the
1433 environment, U-Boot proceed to autoboot; the
1434 previous output (banner, info printfs) will be
1437 See also: doc/README.Modem
1440 Configuration Settings:
1441 -----------------------
1443 - CFG_LONGHELP: Defined when you want long help messages included;
1444 undefine this when you're short of memory.
1446 - CFG_PROMPT: This is what U-Boot prints on the console to
1447 prompt for user input.
1449 - CFG_CBSIZE: Buffer size for input from the Console
1451 - CFG_PBSIZE: Buffer size for Console output
1453 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1455 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1456 the application (usually a Linux kernel) when it is
1459 - CFG_BAUDRATE_TABLE:
1460 List of legal baudrate settings for this board.
1462 - CFG_CONSOLE_INFO_QUIET
1463 Suppress display of console information at boot.
1465 - CFG_CONSOLE_IS_IN_ENV
1466 If the board specific function
1467 extern int overwrite_console (void);
1468 returns 1, the stdin, stderr and stdout are switched to the
1469 serial port, else the settings in the environment are used.
1471 - CFG_CONSOLE_OVERWRITE_ROUTINE
1472 Enable the call to overwrite_console().
1474 - CFG_CONSOLE_ENV_OVERWRITE
1475 Enable overwrite of previous console environment settings.
1477 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1478 Begin and End addresses of the area used by the
1482 Enable an alternate, more extensive memory test.
1484 - CFG_MEMTEST_SCRATCH:
1485 Scratch address used by the alternate memory test
1486 You only need to set this if address zero isn't writeable
1488 - CFG_TFTP_LOADADDR:
1489 Default load address for network file downloads
1491 - CFG_LOADS_BAUD_CHANGE:
1492 Enable temporary baudrate change while serial download
1495 Physical start address of SDRAM. _Must_ be 0 here.
1498 Physical start address of Motherboard I/O (if using a
1502 Physical start address of Flash memory.
1505 Physical start address of boot monitor code (set by
1506 make config files to be same as the text base address
1507 (TEXT_BASE) used when linking) - same as
1508 CFG_FLASH_BASE when booting from flash.
1511 Size of memory reserved for monitor code, used to
1512 determine _at_compile_time_ (!) if the environment is
1513 embedded within the U-Boot image, or in a separate
1517 Size of DRAM reserved for malloc() use.
1520 Maximum size of memory mapped by the startup code of
1521 the Linux kernel; all data that must be processed by
1522 the Linux kernel (bd_info, boot arguments, eventually
1523 initrd image) must be put below this limit.
1525 - CFG_MAX_FLASH_BANKS:
1526 Max number of Flash memory banks
1528 - CFG_MAX_FLASH_SECT:
1529 Max number of sectors on a Flash chip
1531 - CFG_FLASH_ERASE_TOUT:
1532 Timeout for Flash erase operations (in ms)
1534 - CFG_FLASH_WRITE_TOUT:
1535 Timeout for Flash write operations (in ms)
1537 - CFG_FLASH_LOCK_TOUT
1538 Timeout for Flash set sector lock bit operation (in ms)
1540 - CFG_FLASH_UNLOCK_TOUT
1541 Timeout for Flash clear lock bits operation (in ms)
1543 - CFG_FLASH_PROTECTION
1544 If defined, hardware flash sectors protection is used
1545 instead of U-Boot software protection.
1547 - CFG_DIRECT_FLASH_TFTP:
1549 Enable TFTP transfers directly to flash memory;
1550 without this option such a download has to be
1551 performed in two steps: (1) download to RAM, and (2)
1552 copy from RAM to flash.
1554 The two-step approach is usually more reliable, since
1555 you can check if the download worked before you erase
1556 the flash, but in some situations (when sytem RAM is
1557 too limited to allow for a tempory copy of the
1558 downloaded image) this option may be very useful.
1561 Define if the flash driver uses extra elements in the
1562 common flash structure for storing flash geometry.
1564 - CFG_FLASH_CFI_DRIVER
1565 This option also enables the building of the cfi_flash driver
1566 in the drivers directory
1568 - CFG_RX_ETH_BUFFER:
1569 Defines the number of ethernet receive buffers. On some
1570 ethernet controllers it is recommended to set this value
1571 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1572 buffers can be full shortly after enabling the interface
1573 on high ethernet traffic.
1574 Defaults to 4 if not defined.
1576 The following definitions that deal with the placement and management
1577 of environment data (variable area); in general, we support the
1578 following configurations:
1580 - CFG_ENV_IS_IN_FLASH:
1582 Define this if the environment is in flash memory.
1584 a) The environment occupies one whole flash sector, which is
1585 "embedded" in the text segment with the U-Boot code. This
1586 happens usually with "bottom boot sector" or "top boot
1587 sector" type flash chips, which have several smaller
1588 sectors at the start or the end. For instance, such a
1589 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1590 such a case you would place the environment in one of the
1591 4 kB sectors - with U-Boot code before and after it. With
1592 "top boot sector" type flash chips, you would put the
1593 environment in one of the last sectors, leaving a gap
1594 between U-Boot and the environment.
1598 Offset of environment data (variable area) to the
1599 beginning of flash memory; for instance, with bottom boot
1600 type flash chips the second sector can be used: the offset
1601 for this sector is given here.
1603 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1607 This is just another way to specify the start address of
1608 the flash sector containing the environment (instead of
1611 - CFG_ENV_SECT_SIZE:
1613 Size of the sector containing the environment.
1616 b) Sometimes flash chips have few, equal sized, BIG sectors.
1617 In such a case you don't want to spend a whole sector for
1622 If you use this in combination with CFG_ENV_IS_IN_FLASH
1623 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1624 of this flash sector for the environment. This saves
1625 memory for the RAM copy of the environment.
1627 It may also save flash memory if you decide to use this
1628 when your environment is "embedded" within U-Boot code,
1629 since then the remainder of the flash sector could be used
1630 for U-Boot code. It should be pointed out that this is
1631 STRONGLY DISCOURAGED from a robustness point of view:
1632 updating the environment in flash makes it always
1633 necessary to erase the WHOLE sector. If something goes
1634 wrong before the contents has been restored from a copy in
1635 RAM, your target system will be dead.
1637 - CFG_ENV_ADDR_REDUND
1640 These settings describe a second storage area used to hold
1641 a redundand copy of the environment data, so that there is
1642 a valid backup copy in case there is a power failure during
1643 a "saveenv" operation.
1645 BE CAREFUL! Any changes to the flash layout, and some changes to the
1646 source code will make it necessary to adapt <board>/u-boot.lds*
1650 - CFG_ENV_IS_IN_NVRAM:
1652 Define this if you have some non-volatile memory device
1653 (NVRAM, battery buffered SRAM) which you want to use for the
1659 These two #defines are used to determin the memory area you
1660 want to use for environment. It is assumed that this memory
1661 can just be read and written to, without any special
1664 BE CAREFUL! The first access to the environment happens quite early
1665 in U-Boot initalization (when we try to get the setting of for the
1666 console baudrate). You *MUST* have mappend your NVRAM area then, or
1669 Please note that even with NVRAM we still use a copy of the
1670 environment in RAM: we could work on NVRAM directly, but we want to
1671 keep settings there always unmodified except somebody uses "saveenv"
1672 to save the current settings.
1675 - CFG_ENV_IS_IN_EEPROM:
1677 Use this if you have an EEPROM or similar serial access
1678 device and a driver for it.
1683 These two #defines specify the offset and size of the
1684 environment area within the total memory of your EEPROM.
1686 - CFG_I2C_EEPROM_ADDR:
1687 If defined, specified the chip address of the EEPROM device.
1688 The default address is zero.
1690 - CFG_EEPROM_PAGE_WRITE_BITS:
1691 If defined, the number of bits used to address bytes in a
1692 single page in the EEPROM device. A 64 byte page, for example
1693 would require six bits.
1695 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1696 If defined, the number of milliseconds to delay between
1697 page writes. The default is zero milliseconds.
1699 - CFG_I2C_EEPROM_ADDR_LEN:
1700 The length in bytes of the EEPROM memory array address. Note
1701 that this is NOT the chip address length!
1704 The size in bytes of the EEPROM device.
1707 - CFG_ENV_IS_IN_DATAFLASH:
1709 Define this if you have a DataFlash memory device which you
1710 want to use for the environment.
1716 These three #defines specify the offset and size of the
1717 environment area within the total memory of your DataFlash placed
1718 at the specified address.
1721 - CFG_SPI_INIT_OFFSET
1723 Defines offset to the initial SPI buffer area in DPRAM. The
1724 area is used at an early stage (ROM part) if the environment
1725 is configured to reside in the SPI EEPROM: We need a 520 byte
1726 scratch DPRAM area. It is used between the two initialization
1727 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1728 to be a good choice since it makes it far enough from the
1729 start of the data area as well as from the stack pointer.
1731 Please note that the environment is read-only as long as the monitor
1732 has been relocated to RAM and a RAM copy of the environment has been
1733 created; also, when using EEPROM you will have to use getenv_r()
1734 until then to read environment variables.
1736 The environment is protected by a CRC32 checksum. Before the monitor
1737 is relocated into RAM, as a result of a bad CRC you will be working
1738 with the compiled-in default environment - *silently*!!! [This is
1739 necessary, because the first environment variable we need is the
1740 "baudrate" setting for the console - if we have a bad CRC, we don't
1741 have any device yet where we could complain.]
1743 Note: once the monitor has been relocated, then it will complain if
1744 the default environment is used; a new CRC is computed as soon as you
1745 use the "saveenv" command to store a valid environment.
1747 - CFG_FAULT_ECHO_LINK_DOWN:
1748 Echo the inverted Ethernet link state to the fault LED.
1750 Note: If this option is active, then CFG_FAULT_MII_ADDR
1751 also needs to be defined.
1753 - CFG_FAULT_MII_ADDR:
1754 MII address of the PHY to check for the Ethernet link state.
1756 - CFG_64BIT_VSPRINTF:
1757 Makes vsprintf (and all *printf functions) support printing
1758 of 64bit values by using the L quantifier
1760 - CFG_64BIT_STRTOUL:
1761 Adds simple_strtoull that returns a 64bit value
1763 Low Level (hardware related) configuration options:
1764 ---------------------------------------------------
1766 - CFG_CACHELINE_SIZE:
1767 Cache Line Size of the CPU.
1770 Default address of the IMMR after system reset.
1772 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1773 and RPXsuper) to be able to adjust the position of
1774 the IMMR register after a reset.
1776 - Floppy Disk Support:
1777 CFG_FDC_DRIVE_NUMBER
1779 the default drive number (default value 0)
1783 defines the spacing between fdc chipset registers
1788 defines the offset of register from address. It
1789 depends on which part of the data bus is connected to
1790 the fdc chipset. (default value 0)
1792 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1793 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1796 if CFG_FDC_HW_INIT is defined, then the function
1797 fdc_hw_init() is called at the beginning of the FDC
1798 setup. fdc_hw_init() must be provided by the board
1799 source code. It is used to make hardware dependant
1802 - CFG_IMMR: Physical address of the Internal Memory Mapped
1803 Register; DO NOT CHANGE! (11-4)
1804 [MPC8xx systems only]
1806 - CFG_INIT_RAM_ADDR:
1808 Start address of memory area that can be used for
1809 initial data and stack; please note that this must be
1810 writable memory that is working WITHOUT special
1811 initialization, i. e. you CANNOT use normal RAM which
1812 will become available only after programming the
1813 memory controller and running certain initialization
1816 U-Boot uses the following memory types:
1817 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1818 - MPC824X: data cache
1819 - PPC4xx: data cache
1821 - CFG_GBL_DATA_OFFSET:
1823 Offset of the initial data structure in the memory
1824 area defined by CFG_INIT_RAM_ADDR. Usually
1825 CFG_GBL_DATA_OFFSET is chosen such that the initial
1826 data is located at the end of the available space
1827 (sometimes written as (CFG_INIT_RAM_END -
1828 CFG_INIT_DATA_SIZE), and the initial stack is just
1829 below that area (growing from (CFG_INIT_RAM_ADDR +
1830 CFG_GBL_DATA_OFFSET) downward.
1833 On the MPC824X (or other systems that use the data
1834 cache for initial memory) the address chosen for
1835 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1836 point to an otherwise UNUSED address space between
1837 the top of RAM and the start of the PCI space.
1839 - CFG_SIUMCR: SIU Module Configuration (11-6)
1841 - CFG_SYPCR: System Protection Control (11-9)
1843 - CFG_TBSCR: Time Base Status and Control (11-26)
1845 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1847 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1849 - CFG_SCCR: System Clock and reset Control Register (15-27)
1851 - CFG_OR_TIMING_SDRAM:
1855 periodic timer for refresh
1857 - CFG_DER: Debug Event Register (37-47)
1859 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1860 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1861 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1863 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1865 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1866 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1867 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1868 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1870 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1871 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1872 Machine Mode Register and Memory Periodic Timer
1873 Prescaler definitions (SDRAM timing)
1875 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1876 enable I2C microcode relocation patch (MPC8xx);
1877 define relocation offset in DPRAM [DSP2]
1879 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1880 enable SPI microcode relocation patch (MPC8xx);
1881 define relocation offset in DPRAM [SCC4]
1884 Use OSCM clock mode on MBX8xx board. Be careful,
1885 wrong setting might damage your board. Read
1886 doc/README.MBX before setting this variable!
1888 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1889 Offset of the bootmode word in DPRAM used by post
1890 (Power On Self Tests). This definition overrides
1891 #define'd default value in commproc.h resp.
1894 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1895 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1896 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1897 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1898 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1899 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1900 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1901 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1902 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1904 Building the Software:
1905 ======================
1907 Building U-Boot has been tested in native PPC environments (on a
1908 PowerBook G3 running LinuxPPC 2000) and in cross environments
1909 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1912 If you are not using a native PPC environment, it is assumed that you
1913 have the GNU cross compiling tools available in your path and named
1914 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1915 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1916 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1919 CROSS_COMPILE = ppc_4xx-
1922 U-Boot is intended to be simple to build. After installing the
1923 sources you must configure U-Boot for one specific board type. This
1928 where "NAME_config" is the name of one of the existing
1929 configurations; the following names are supported:
1931 ADCIOP_config GTH_config TQM850L_config
1932 ADS860_config IP860_config TQM855L_config
1933 AR405_config IVML24_config TQM860L_config
1934 CANBT_config IVMS8_config WALNUT405_config
1935 CPCI405_config LANTEC_config cogent_common_config
1936 CPCIISER4_config MBX_config cogent_mpc8260_config
1937 CU824_config MBX860T_config cogent_mpc8xx_config
1938 ESTEEM192E_config RPXlite_config hermes_config
1939 ETX094_config RPXsuper_config hymod_config
1940 FADS823_config SM850_config lwmon_config
1941 FADS850SAR_config SPD823TS_config pcu_e_config
1942 FADS860T_config SXNI855T_config rsdproto_config
1943 FPS850L_config Sandpoint8240_config sbc8260_config
1944 GENIETV_config TQM823L_config PIP405_config
1945 GEN860T_config EBONY_config FPS860L_config
1946 ELPT860_config cmi_mpc5xx_config NETVIA_config
1947 at91rm9200dk_config omap1510inn_config MPC8260ADS_config
1948 omap1610inn_config ZPC1900_config MPC8540ADS_config
1949 MPC8560ADS_config QS850_config QS823_config
1950 QS860T_config DUET_ADS_config omap1610h2_config
1952 Note: for some board special configuration names may exist; check if
1953 additional information is available from the board vendor; for
1954 instance, the TQM8xxL systems run normally at 50 MHz and use a
1955 SCC for 10baseT ethernet; there are also systems with 80 MHz
1956 CPU clock, and an optional Fast Ethernet module is available
1957 for CPU's with FEC. You can select such additional "features"
1958 when chosing the configuration, i. e.
1961 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1963 make TQM860L_FEC_config
1964 - will configure for a TQM860L at 50MHz with FEC for ethernet
1966 make TQM860L_80MHz_config
1967 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1970 make TQM860L_FEC_80MHz_config
1971 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1973 make TQM823L_LCD_config
1974 - will configure for a TQM823L with U-Boot console on LCD
1976 make TQM823L_LCD_80MHz_config
1977 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1982 Finally, type "make all", and you should get some working U-Boot
1983 images ready for download to / installation on your system:
1985 - "u-boot.bin" is a raw binary image
1986 - "u-boot" is an image in ELF binary format
1987 - "u-boot.srec" is in Motorola S-Record format
1990 Please be aware that the Makefiles assume you are using GNU make, so
1991 for instance on NetBSD you might need to use "gmake" instead of
1995 If the system board that you have is not listed, then you will need
1996 to port U-Boot to your hardware platform. To do this, follow these
1999 1. Add a new configuration option for your board to the toplevel
2000 "Makefile" and to the "MAKEALL" script, using the existing
2001 entries as examples. Note that here and at many other places
2002 boards and other names are listed in alphabetical sort order. Please
2004 2. Create a new directory to hold your board specific code. Add any
2005 files you need. In your board directory, you will need at least
2006 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2007 3. Create a new configuration file "include/configs/<board>.h" for
2009 3. If you're porting U-Boot to a new CPU, then also create a new
2010 directory to hold your CPU specific code. Add any files you need.
2011 4. Run "make <board>_config" with your new name.
2012 5. Type "make", and you should get a working "u-boot.srec" file
2013 to be installed on your target system.
2014 6. Debug and solve any problems that might arise.
2015 [Of course, this last step is much harder than it sounds.]
2018 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2019 ==============================================================
2021 If you have modified U-Boot sources (for instance added a new board
2022 or support for new devices, a new CPU, etc.) you are expected to
2023 provide feedback to the other developers. The feedback normally takes
2024 the form of a "patch", i. e. a context diff against a certain (latest
2025 official or latest in CVS) version of U-Boot sources.
2027 But before you submit such a patch, please verify that your modifi-
2028 cation did not break existing code. At least make sure that *ALL* of
2029 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2030 just run the "MAKEALL" script, which will configure and build U-Boot
2031 for ALL supported system. Be warned, this will take a while. You can
2032 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2033 environment variable to the script, i. e. to use the cross tools from
2034 MontaVista's Hard Hat Linux you can type
2036 CROSS_COMPILE=ppc_8xx- MAKEALL
2038 or to build on a native PowerPC system you can type
2040 CROSS_COMPILE=' ' MAKEALL
2042 See also "U-Boot Porting Guide" below.
2045 Monitor Commands - Overview:
2046 ============================
2048 go - start application at address 'addr'
2049 run - run commands in an environment variable
2050 bootm - boot application image from memory
2051 bootp - boot image via network using BootP/TFTP protocol
2052 tftpboot- boot image via network using TFTP protocol
2053 and env variables "ipaddr" and "serverip"
2054 (and eventually "gatewayip")
2055 rarpboot- boot image via network using RARP/TFTP protocol
2056 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2057 loads - load S-Record file over serial line
2058 loadb - load binary file over serial line (kermit mode)
2060 mm - memory modify (auto-incrementing)
2061 nm - memory modify (constant address)
2062 mw - memory write (fill)
2064 cmp - memory compare
2065 crc32 - checksum calculation
2066 imd - i2c memory display
2067 imm - i2c memory modify (auto-incrementing)
2068 inm - i2c memory modify (constant address)
2069 imw - i2c memory write (fill)
2070 icrc32 - i2c checksum calculation
2071 iprobe - probe to discover valid I2C chip addresses
2072 iloop - infinite loop on address range
2073 isdram - print SDRAM configuration information
2074 sspi - SPI utility commands
2075 base - print or set address offset
2076 printenv- print environment variables
2077 setenv - set environment variables
2078 saveenv - save environment variables to persistent storage
2079 protect - enable or disable FLASH write protection
2080 erase - erase FLASH memory
2081 flinfo - print FLASH memory information
2082 bdinfo - print Board Info structure
2083 iminfo - print header information for application image
2084 coninfo - print console devices and informations
2085 ide - IDE sub-system
2086 loop - infinite loop on address range
2087 mtest - simple RAM test
2088 icache - enable or disable instruction cache
2089 dcache - enable or disable data cache
2090 reset - Perform RESET of the CPU
2091 echo - echo args to console
2092 version - print monitor version
2093 help - print online help
2094 ? - alias for 'help'
2097 Monitor Commands - Detailed Description:
2098 ========================================
2102 For now: just type "help <command>".
2105 Environment Variables:
2106 ======================
2108 U-Boot supports user configuration using Environment Variables which
2109 can be made persistent by saving to Flash memory.
2111 Environment Variables are set using "setenv", printed using
2112 "printenv", and saved to Flash using "saveenv". Using "setenv"
2113 without a value can be used to delete a variable from the
2114 environment. As long as you don't save the environment you are
2115 working with an in-memory copy. In case the Flash area containing the
2116 environment is erased by accident, a default environment is provided.
2118 Some configuration options can be set using Environment Variables:
2120 baudrate - see CONFIG_BAUDRATE
2122 bootdelay - see CONFIG_BOOTDELAY
2124 bootcmd - see CONFIG_BOOTCOMMAND
2126 bootargs - Boot arguments when booting an RTOS image
2128 bootfile - Name of the image to load with TFTP
2130 autoload - if set to "no" (any string beginning with 'n'),
2131 "bootp" will just load perform a lookup of the
2132 configuration from the BOOTP server, but not try to
2133 load any image using TFTP
2135 autostart - if set to "yes", an image loaded using the "bootp",
2136 "rarpboot", "tftpboot" or "diskboot" commands will
2137 be automatically started (by internally calling
2140 If set to "no", a standalone image passed to the
2141 "bootm" command will be copied to the load address
2142 (and eventually uncompressed), but NOT be started.
2143 This can be used to load and uncompress arbitrary
2146 initrd_high - restrict positioning of initrd images:
2147 If this variable is not set, initrd images will be
2148 copied to the highest possible address in RAM; this
2149 is usually what you want since it allows for
2150 maximum initrd size. If for some reason you want to
2151 make sure that the initrd image is loaded below the
2152 CFG_BOOTMAPSZ limit, you can set this environment
2153 variable to a value of "no" or "off" or "0".
2154 Alternatively, you can set it to a maximum upper
2155 address to use (U-Boot will still check that it
2156 does not overwrite the U-Boot stack and data).
2158 For instance, when you have a system with 16 MB
2159 RAM, and want to reserve 4 MB from use by Linux,
2160 you can do this by adding "mem=12M" to the value of
2161 the "bootargs" variable. However, now you must make
2162 sure that the initrd image is placed in the first
2163 12 MB as well - this can be done with
2165 setenv initrd_high 00c00000
2167 If you set initrd_high to 0xFFFFFFFF, this is an
2168 indication to U-Boot that all addresses are legal
2169 for the Linux kernel, including addresses in flash
2170 memory. In this case U-Boot will NOT COPY the
2171 ramdisk at all. This may be useful to reduce the
2172 boot time on your system, but requires that this
2173 feature is supported by your Linux kernel.
2175 ipaddr - IP address; needed for tftpboot command
2177 loadaddr - Default load address for commands like "bootp",
2178 "rarpboot", "tftpboot", "loadb" or "diskboot"
2180 loads_echo - see CONFIG_LOADS_ECHO
2182 serverip - TFTP server IP address; needed for tftpboot command
2184 bootretry - see CONFIG_BOOT_RETRY_TIME
2186 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2188 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2191 The following environment variables may be used and automatically
2192 updated by the network boot commands ("bootp" and "rarpboot"),
2193 depending the information provided by your boot server:
2195 bootfile - see above
2196 dnsip - IP address of your Domain Name Server
2197 dnsip2 - IP address of your secondary Domain Name Server
2198 gatewayip - IP address of the Gateway (Router) to use
2199 hostname - Target hostname
2201 netmask - Subnet Mask
2202 rootpath - Pathname of the root filesystem on the NFS server
2203 serverip - see above
2206 There are two special Environment Variables:
2208 serial# - contains hardware identification information such
2209 as type string and/or serial number
2210 ethaddr - Ethernet address
2212 These variables can be set only once (usually during manufacturing of
2213 the board). U-Boot refuses to delete or overwrite these variables
2214 once they have been set once.
2217 Further special Environment Variables:
2219 ver - Contains the U-Boot version string as printed
2220 with the "version" command. This variable is
2221 readonly (see CONFIG_VERSION_VARIABLE).
2224 Please note that changes to some configuration parameters may take
2225 only effect after the next boot (yes, that's just like Windoze :-).
2228 Command Line Parsing:
2229 =====================
2231 There are two different command line parsers available with U-Boot:
2232 the old "simple" one, and the much more powerful "hush" shell:
2234 Old, simple command line parser:
2235 --------------------------------
2237 - supports environment variables (through setenv / saveenv commands)
2238 - several commands on one line, separated by ';'
2239 - variable substitution using "... $(name) ..." syntax
2240 - special characters ('$', ';') can be escaped by prefixing with '\',
2242 setenv bootcmd bootm \$(address)
2243 - You can also escape text by enclosing in single apostrophes, for example:
2244 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2249 - similar to Bourne shell, with control structures like
2250 if...then...else...fi, for...do...done; while...do...done,
2251 until...do...done, ...
2252 - supports environment ("global") variables (through setenv / saveenv
2253 commands) and local shell variables (through standard shell syntax
2254 "name=value"); only environment variables can be used with "run"
2260 (1) If a command line (or an environment variable executed by a "run"
2261 command) contains several commands separated by semicolon, and
2262 one of these commands fails, then the remaining commands will be
2265 (2) If you execute several variables with one call to run (i. e.
2266 calling run with a list af variables as arguments), any failing
2267 command will cause "run" to terminate, i. e. the remaining
2268 variables are not executed.
2270 Note for Redundant Ethernet Interfaces:
2271 =======================================
2273 Some boards come with redundant ethernet interfaces; U-Boot supports
2274 such configurations and is capable of automatic selection of a
2275 "working" interface when needed. MAC assignment works as follows:
2277 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2278 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2279 "eth1addr" (=>eth1), "eth2addr", ...
2281 If the network interface stores some valid MAC address (for instance
2282 in SROM), this is used as default address if there is NO correspon-
2283 ding setting in the environment; if the corresponding environment
2284 variable is set, this overrides the settings in the card; that means:
2286 o If the SROM has a valid MAC address, and there is no address in the
2287 environment, the SROM's address is used.
2289 o If there is no valid address in the SROM, and a definition in the
2290 environment exists, then the value from the environment variable is
2293 o If both the SROM and the environment contain a MAC address, and
2294 both addresses are the same, this MAC address is used.
2296 o If both the SROM and the environment contain a MAC address, and the
2297 addresses differ, the value from the environment is used and a
2300 o If neither SROM nor the environment contain a MAC address, an error
2307 The "boot" commands of this monitor operate on "image" files which
2308 can be basicly anything, preceeded by a special header; see the
2309 definitions in include/image.h for details; basicly, the header
2310 defines the following image properties:
2312 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2313 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2314 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2315 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2316 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2317 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2318 Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2319 * Compression Type (uncompressed, gzip, bzip2)
2325 The header is marked by a special Magic Number, and both the header
2326 and the data portions of the image are secured against corruption by
2333 Although U-Boot should support any OS or standalone application
2334 easily, the main focus has always been on Linux during the design of
2337 U-Boot includes many features that so far have been part of some
2338 special "boot loader" code within the Linux kernel. Also, any
2339 "initrd" images to be used are no longer part of one big Linux image;
2340 instead, kernel and "initrd" are separate images. This implementation
2341 serves several purposes:
2343 - the same features can be used for other OS or standalone
2344 applications (for instance: using compressed images to reduce the
2345 Flash memory footprint)
2347 - it becomes much easier to port new Linux kernel versions because
2348 lots of low-level, hardware dependent stuff are done by U-Boot
2350 - the same Linux kernel image can now be used with different "initrd"
2351 images; of course this also means that different kernel images can
2352 be run with the same "initrd". This makes testing easier (you don't
2353 have to build a new "zImage.initrd" Linux image when you just
2354 change a file in your "initrd"). Also, a field-upgrade of the
2355 software is easier now.
2361 Porting Linux to U-Boot based systems:
2362 ---------------------------------------
2364 U-Boot cannot save you from doing all the necessary modifications to
2365 configure the Linux device drivers for use with your target hardware
2366 (no, we don't intend to provide a full virtual machine interface to
2369 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2371 Just make sure your machine specific header file (for instance
2372 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2373 Information structure as we define in include/u-boot.h, and make
2374 sure that your definition of IMAP_ADDR uses the same value as your
2375 U-Boot configuration in CFG_IMMR.
2378 Configuring the Linux kernel:
2379 -----------------------------
2381 No specific requirements for U-Boot. Make sure you have some root
2382 device (initial ramdisk, NFS) for your target system.
2385 Building a Linux Image:
2386 -----------------------
2388 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2389 not used. If you use recent kernel source, a new build target
2390 "uImage" will exist which automatically builds an image usable by
2391 U-Boot. Most older kernels also have support for a "pImage" target,
2392 which was introduced for our predecessor project PPCBoot and uses a
2393 100% compatible format.
2402 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2403 encapsulate a compressed Linux kernel image with header information,
2404 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2406 * build a standard "vmlinux" kernel image (in ELF binary format):
2408 * convert the kernel into a raw binary image:
2410 ${CROSS_COMPILE}-objcopy -O binary \
2411 -R .note -R .comment \
2412 -S vmlinux linux.bin
2414 * compress the binary image:
2418 * package compressed binary image for U-Boot:
2420 mkimage -A ppc -O linux -T kernel -C gzip \
2421 -a 0 -e 0 -n "Linux Kernel Image" \
2422 -d linux.bin.gz uImage
2425 The "mkimage" tool can also be used to create ramdisk images for use
2426 with U-Boot, either separated from the Linux kernel image, or
2427 combined into one file. "mkimage" encapsulates the images with a 64
2428 byte header containing information about target architecture,
2429 operating system, image type, compression method, entry points, time
2430 stamp, CRC32 checksums, etc.
2432 "mkimage" can be called in two ways: to verify existing images and
2433 print the header information, or to build new images.
2435 In the first form (with "-l" option) mkimage lists the information
2436 contained in the header of an existing U-Boot image; this includes
2437 checksum verification:
2439 tools/mkimage -l image
2440 -l ==> list image header information
2442 The second form (with "-d" option) is used to build a U-Boot image
2443 from a "data file" which is used as image payload:
2445 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2446 -n name -d data_file image
2447 -A ==> set architecture to 'arch'
2448 -O ==> set operating system to 'os'
2449 -T ==> set image type to 'type'
2450 -C ==> set compression type 'comp'
2451 -a ==> set load address to 'addr' (hex)
2452 -e ==> set entry point to 'ep' (hex)
2453 -n ==> set image name to 'name'
2454 -d ==> use image data from 'datafile'
2456 Right now, all Linux kernels use the same load address (0x00000000),
2457 but the entry point address depends on the kernel version:
2459 - 2.2.x kernels have the entry point at 0x0000000C,
2460 - 2.3.x and later kernels have the entry point at 0x00000000.
2462 So a typical call to build a U-Boot image would read:
2464 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2465 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2466 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2467 > examples/uImage.TQM850L
2468 Image Name: 2.4.4 kernel for TQM850L
2469 Created: Wed Jul 19 02:34:59 2000
2470 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2471 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2472 Load Address: 0x00000000
2473 Entry Point: 0x00000000
2475 To verify the contents of the image (or check for corruption):
2477 -> tools/mkimage -l examples/uImage.TQM850L
2478 Image Name: 2.4.4 kernel for TQM850L
2479 Created: Wed Jul 19 02:34:59 2000
2480 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2481 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2482 Load Address: 0x00000000
2483 Entry Point: 0x00000000
2485 NOTE: for embedded systems where boot time is critical you can trade
2486 speed for memory and install an UNCOMPRESSED image instead: this
2487 needs more space in Flash, but boots much faster since it does not
2488 need to be uncompressed:
2490 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2491 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2492 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2493 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2494 > examples/uImage.TQM850L-uncompressed
2495 Image Name: 2.4.4 kernel for TQM850L
2496 Created: Wed Jul 19 02:34:59 2000
2497 Image Type: PowerPC Linux Kernel Image (uncompressed)
2498 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2499 Load Address: 0x00000000
2500 Entry Point: 0x00000000
2503 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2504 when your kernel is intended to use an initial ramdisk:
2506 -> tools/mkimage -n 'Simple Ramdisk Image' \
2507 > -A ppc -O linux -T ramdisk -C gzip \
2508 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2509 Image Name: Simple Ramdisk Image
2510 Created: Wed Jan 12 14:01:50 2000
2511 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2512 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2513 Load Address: 0x00000000
2514 Entry Point: 0x00000000
2517 Installing a Linux Image:
2518 -------------------------
2520 To downloading a U-Boot image over the serial (console) interface,
2521 you must convert the image to S-Record format:
2523 objcopy -I binary -O srec examples/image examples/image.srec
2525 The 'objcopy' does not understand the information in the U-Boot
2526 image header, so the resulting S-Record file will be relative to
2527 address 0x00000000. To load it to a given address, you need to
2528 specify the target address as 'offset' parameter with the 'loads'
2531 Example: install the image to address 0x40100000 (which on the
2532 TQM8xxL is in the first Flash bank):
2534 => erase 40100000 401FFFFF
2540 ## Ready for S-Record download ...
2541 ~>examples/image.srec
2542 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2544 15989 15990 15991 15992
2545 [file transfer complete]
2547 ## Start Addr = 0x00000000
2550 You can check the success of the download using the 'iminfo' command;
2551 this includes a checksum verification so you can be sure no data
2552 corruption happened:
2556 ## Checking Image at 40100000 ...
2557 Image Name: 2.2.13 for initrd on TQM850L
2558 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2559 Data Size: 335725 Bytes = 327 kB = 0 MB
2560 Load Address: 00000000
2561 Entry Point: 0000000c
2562 Verifying Checksum ... OK
2568 The "bootm" command is used to boot an application that is stored in
2569 memory (RAM or Flash). In case of a Linux kernel image, the contents
2570 of the "bootargs" environment variable is passed to the kernel as
2571 parameters. You can check and modify this variable using the
2572 "printenv" and "setenv" commands:
2575 => printenv bootargs
2576 bootargs=root=/dev/ram
2578 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2580 => printenv bootargs
2581 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2584 ## Booting Linux kernel at 40020000 ...
2585 Image Name: 2.2.13 for NFS on TQM850L
2586 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2587 Data Size: 381681 Bytes = 372 kB = 0 MB
2588 Load Address: 00000000
2589 Entry Point: 0000000c
2590 Verifying Checksum ... OK
2591 Uncompressing Kernel Image ... OK
2592 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
2593 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2594 time_init: decrementer frequency = 187500000/60
2595 Calibrating delay loop... 49.77 BogoMIPS
2596 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2599 If you want to boot a Linux kernel with initial ram disk, you pass
2600 the memory addresses of both the kernel and the initrd image (PPBCOOT
2601 format!) to the "bootm" command:
2603 => imi 40100000 40200000
2605 ## Checking Image at 40100000 ...
2606 Image Name: 2.2.13 for initrd on TQM850L
2607 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2608 Data Size: 335725 Bytes = 327 kB = 0 MB
2609 Load Address: 00000000
2610 Entry Point: 0000000c
2611 Verifying Checksum ... OK
2613 ## Checking Image at 40200000 ...
2614 Image Name: Simple Ramdisk Image
2615 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2616 Data Size: 566530 Bytes = 553 kB = 0 MB
2617 Load Address: 00000000
2618 Entry Point: 00000000
2619 Verifying Checksum ... OK
2621 => bootm 40100000 40200000
2622 ## Booting Linux kernel at 40100000 ...
2623 Image Name: 2.2.13 for initrd on TQM850L
2624 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2625 Data Size: 335725 Bytes = 327 kB = 0 MB
2626 Load Address: 00000000
2627 Entry Point: 0000000c
2628 Verifying Checksum ... OK
2629 Uncompressing Kernel Image ... OK
2630 ## Loading RAMDisk Image at 40200000 ...
2631 Image Name: Simple Ramdisk Image
2632 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2633 Data Size: 566530 Bytes = 553 kB = 0 MB
2634 Load Address: 00000000
2635 Entry Point: 00000000
2636 Verifying Checksum ... OK
2637 Loading Ramdisk ... OK
2638 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
2639 Boot arguments: root=/dev/ram
2640 time_init: decrementer frequency = 187500000/60
2641 Calibrating delay loop... 49.77 BogoMIPS
2643 RAMDISK: Compressed image found at block 0
2644 VFS: Mounted root (ext2 filesystem).
2648 More About U-Boot Image Types:
2649 ------------------------------
2651 U-Boot supports the following image types:
2653 "Standalone Programs" are directly runnable in the environment
2654 provided by U-Boot; it is expected that (if they behave
2655 well) you can continue to work in U-Boot after return from
2656 the Standalone Program.
2657 "OS Kernel Images" are usually images of some Embedded OS which
2658 will take over control completely. Usually these programs
2659 will install their own set of exception handlers, device
2660 drivers, set up the MMU, etc. - this means, that you cannot
2661 expect to re-enter U-Boot except by resetting the CPU.
2662 "RAMDisk Images" are more or less just data blocks, and their
2663 parameters (address, size) are passed to an OS kernel that is
2665 "Multi-File Images" contain several images, typically an OS
2666 (Linux) kernel image and one or more data images like
2667 RAMDisks. This construct is useful for instance when you want
2668 to boot over the network using BOOTP etc., where the boot
2669 server provides just a single image file, but you want to get
2670 for instance an OS kernel and a RAMDisk image.
2672 "Multi-File Images" start with a list of image sizes, each
2673 image size (in bytes) specified by an "uint32_t" in network
2674 byte order. This list is terminated by an "(uint32_t)0".
2675 Immediately after the terminating 0 follow the images, one by
2676 one, all aligned on "uint32_t" boundaries (size rounded up to
2677 a multiple of 4 bytes).
2679 "Firmware Images" are binary images containing firmware (like
2680 U-Boot or FPGA images) which usually will be programmed to
2683 "Script files" are command sequences that will be executed by
2684 U-Boot's command interpreter; this feature is especially
2685 useful when you configure U-Boot to use a real shell (hush)
2686 as command interpreter.
2692 One of the features of U-Boot is that you can dynamically load and
2693 run "standalone" applications, which can use some resources of
2694 U-Boot like console I/O functions or interrupt services.
2696 Two simple examples are included with the sources:
2701 'examples/hello_world.c' contains a small "Hello World" Demo
2702 application; it is automatically compiled when you build U-Boot.
2703 It's configured to run at address 0x00040004, so you can play with it
2707 ## Ready for S-Record download ...
2708 ~>examples/hello_world.srec
2709 1 2 3 4 5 6 7 8 9 10 11 ...
2710 [file transfer complete]
2712 ## Start Addr = 0x00040004
2714 => go 40004 Hello World! This is a test.
2715 ## Starting application at 0x00040004 ...
2726 Hit any key to exit ...
2728 ## Application terminated, rc = 0x0
2730 Another example, which demonstrates how to register a CPM interrupt
2731 handler with the U-Boot code, can be found in 'examples/timer.c'.
2732 Here, a CPM timer is set up to generate an interrupt every second.
2733 The interrupt service routine is trivial, just printing a '.'
2734 character, but this is just a demo program. The application can be
2735 controlled by the following keys:
2737 ? - print current values og the CPM Timer registers
2738 b - enable interrupts and start timer
2739 e - stop timer and disable interrupts
2740 q - quit application
2743 ## Ready for S-Record download ...
2744 ~>examples/timer.srec
2745 1 2 3 4 5 6 7 8 9 10 11 ...
2746 [file transfer complete]
2748 ## Start Addr = 0x00040004
2751 ## Starting application at 0x00040004 ...
2754 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2757 [q, b, e, ?] Set interval 1000000 us
2760 [q, b, e, ?] ........
2761 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2764 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2767 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2770 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2772 [q, b, e, ?] ...Stopping timer
2774 [q, b, e, ?] ## Application terminated, rc = 0x0
2780 Over time, many people have reported problems when trying to use the
2781 "minicom" terminal emulation program for serial download. I (wd)
2782 consider minicom to be broken, and recommend not to use it. Under
2783 Unix, I recommend to use C-Kermit for general purpose use (and
2784 especially for kermit binary protocol download ("loadb" command), and
2785 use "cu" for S-Record download ("loads" command).
2787 Nevertheless, if you absolutely want to use it try adding this
2788 configuration to your "File transfer protocols" section:
2790 Name Program Name U/D FullScr IO-Red. Multi
2791 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2792 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2798 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2799 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2801 Building requires a cross environment; it is known to work on
2802 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2803 need gmake since the Makefiles are not compatible with BSD make).
2804 Note that the cross-powerpc package does not install include files;
2805 attempting to build U-Boot will fail because <machine/ansi.h> is
2806 missing. This file has to be installed and patched manually:
2808 # cd /usr/pkg/cross/powerpc-netbsd/include
2810 # ln -s powerpc machine
2811 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2812 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2814 Native builds *don't* work due to incompatibilities between native
2815 and U-Boot include files.
2817 Booting assumes that (the first part of) the image booted is a
2818 stage-2 loader which in turn loads and then invokes the kernel
2819 proper. Loader sources will eventually appear in the NetBSD source
2820 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2821 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2825 Implementation Internals:
2826 =========================
2828 The following is not intended to be a complete description of every
2829 implementation detail. However, it should help to understand the
2830 inner workings of U-Boot and make it easier to port it to custom
2834 Initial Stack, Global Data:
2835 ---------------------------
2837 The implementation of U-Boot is complicated by the fact that U-Boot
2838 starts running out of ROM (flash memory), usually without access to
2839 system RAM (because the memory controller is not initialized yet).
2840 This means that we don't have writable Data or BSS segments, and BSS
2841 is not initialized as zero. To be able to get a C environment working
2842 at all, we have to allocate at least a minimal stack. Implementation
2843 options for this are defined and restricted by the CPU used: Some CPU
2844 models provide on-chip memory (like the IMMR area on MPC8xx and
2845 MPC826x processors), on others (parts of) the data cache can be
2846 locked as (mis-) used as memory, etc.
2848 Chris Hallinan posted a good summary of these issues to the
2849 u-boot-users mailing list:
2851 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2852 From: "Chris Hallinan" <clh@net1plus.com>
2853 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2856 Correct me if I'm wrong, folks, but the way I understand it
2857 is this: Using DCACHE as initial RAM for Stack, etc, does not
2858 require any physical RAM backing up the cache. The cleverness
2859 is that the cache is being used as a temporary supply of
2860 necessary storage before the SDRAM controller is setup. It's
2861 beyond the scope of this list to expain the details, but you
2862 can see how this works by studying the cache architecture and
2863 operation in the architecture and processor-specific manuals.
2865 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2866 is another option for the system designer to use as an
2867 initial stack/ram area prior to SDRAM being available. Either
2868 option should work for you. Using CS 4 should be fine if your
2869 board designers haven't used it for something that would
2870 cause you grief during the initial boot! It is frequently not
2873 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2874 with your processor/board/system design. The default value
2875 you will find in any recent u-boot distribution in
2876 Walnut405.h should work for you. I'd set it to a value larger
2877 than your SDRAM module. If you have a 64MB SDRAM module, set
2878 it above 400_0000. Just make sure your board has no resources
2879 that are supposed to respond to that address! That code in
2880 start.S has been around a while and should work as is when
2881 you get the config right.
2886 It is essential to remember this, since it has some impact on the C
2887 code for the initialization procedures:
2889 * Initialized global data (data segment) is read-only. Do not attempt
2892 * Do not use any unitialized global data (or implicitely initialized
2893 as zero data - BSS segment) at all - this is undefined, initiali-
2894 zation is performed later (when relocating to RAM).
2896 * Stack space is very limited. Avoid big data buffers or things like
2899 Having only the stack as writable memory limits means we cannot use
2900 normal global data to share information beween the code. But it
2901 turned out that the implementation of U-Boot can be greatly
2902 simplified by making a global data structure (gd_t) available to all
2903 functions. We could pass a pointer to this data as argument to _all_
2904 functions, but this would bloat the code. Instead we use a feature of
2905 the GCC compiler (Global Register Variables) to share the data: we
2906 place a pointer (gd) to the global data into a register which we
2907 reserve for this purpose.
2909 When choosing a register for such a purpose we are restricted by the
2910 relevant (E)ABI specifications for the current architecture, and by
2911 GCC's implementation.
2913 For PowerPC, the following registers have specific use:
2916 R3-R4: parameter passing and return values
2917 R5-R10: parameter passing
2918 R13: small data area pointer
2922 (U-Boot also uses R14 as internal GOT pointer.)
2924 ==> U-Boot will use R29 to hold a pointer to the global data
2926 Note: on PPC, we could use a static initializer (since the
2927 address of the global data structure is known at compile time),
2928 but it turned out that reserving a register results in somewhat
2929 smaller code - although the code savings are not that big (on
2930 average for all boards 752 bytes for the whole U-Boot image,
2931 624 text + 127 data).
2933 On ARM, the following registers are used:
2935 R0: function argument word/integer result
2936 R1-R3: function argument word
2938 R10: stack limit (used only if stack checking if enabled)
2939 R11: argument (frame) pointer
2940 R12: temporary workspace
2943 R15: program counter
2945 ==> U-Boot will use R8 to hold a pointer to the global data
2951 U-Boot runs in system state and uses physical addresses, i.e. the
2952 MMU is not used either for address mapping nor for memory protection.
2954 The available memory is mapped to fixed addresses using the memory
2955 controller. In this process, a contiguous block is formed for each
2956 memory type (Flash, SDRAM, SRAM), even when it consists of several
2957 physical memory banks.
2959 U-Boot is installed in the first 128 kB of the first Flash bank (on
2960 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2961 booting and sizing and initializing DRAM, the code relocates itself
2962 to the upper end of DRAM. Immediately below the U-Boot code some
2963 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2964 configuration setting]. Below that, a structure with global Board
2965 Info data is placed, followed by the stack (growing downward).
2967 Additionally, some exception handler code is copied to the low 8 kB
2968 of DRAM (0x00000000 ... 0x00001FFF).
2970 So a typical memory configuration with 16 MB of DRAM could look like
2973 0x0000 0000 Exception Vector code
2976 0x0000 2000 Free for Application Use
2982 0x00FB FF20 Monitor Stack (Growing downward)
2983 0x00FB FFAC Board Info Data and permanent copy of global data
2984 0x00FC 0000 Malloc Arena
2987 0x00FE 0000 RAM Copy of Monitor Code
2988 ... eventually: LCD or video framebuffer
2989 ... eventually: pRAM (Protected RAM - unchanged by reset)
2990 0x00FF FFFF [End of RAM]
2993 System Initialization:
2994 ----------------------
2996 In the reset configuration, U-Boot starts at the reset entry point
2997 (on most PowerPC systens at address 0x00000100). Because of the reset
2998 configuration for CS0# this is a mirror of the onboard Flash memory.
2999 To be able to re-map memory U-Boot then jumps to its link address.
3000 To be able to implement the initialization code in C, a (small!)
3001 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3002 which provide such a feature like MPC8xx or MPC8260), or in a locked
3003 part of the data cache. After that, U-Boot initializes the CPU core,
3004 the caches and the SIU.
3006 Next, all (potentially) available memory banks are mapped using a
3007 preliminary mapping. For example, we put them on 512 MB boundaries
3008 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3009 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3010 programmed for SDRAM access. Using the temporary configuration, a
3011 simple memory test is run that determines the size of the SDRAM
3014 When there is more than one SDRAM bank, and the banks are of
3015 different size, the largest is mapped first. For equal size, the first
3016 bank (CS2#) is mapped first. The first mapping is always for address
3017 0x00000000, with any additional banks following immediately to create
3018 contiguous memory starting from 0.
3020 Then, the monitor installs itself at the upper end of the SDRAM area
3021 and allocates memory for use by malloc() and for the global Board
3022 Info data; also, the exception vector code is copied to the low RAM
3023 pages, and the final stack is set up.
3025 Only after this relocation will you have a "normal" C environment;
3026 until that you are restricted in several ways, mostly because you are
3027 running from ROM, and because the code will have to be relocated to a
3031 U-Boot Porting Guide:
3032 ----------------------
3034 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3038 int main (int argc, char *argv[])
3040 sighandler_t no_more_time;
3042 signal (SIGALRM, no_more_time);
3043 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3045 if (available_money > available_manpower) {
3046 pay consultant to port U-Boot;
3050 Download latest U-Boot source;
3052 Subscribe to u-boot-users mailing list;
3055 email ("Hi, I am new to U-Boot, how do I get started?");
3059 Read the README file in the top level directory;
3060 Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3061 Read the source, Luke;
3064 if (available_money > toLocalCurrency ($2500)) {
3067 Add a lot of aggravation and time;
3070 Create your own board support subdirectory;
3072 Create your own board config file;
3076 Add / modify source code;
3080 email ("Hi, I am having problems...");
3082 Send patch file to Wolfgang;
3087 void no_more_time (int sig)
3096 All contributions to U-Boot should conform to the Linux kernel
3097 coding style; see the file "Documentation/CodingStyle" in your Linux
3098 kernel source directory.
3100 Please note that U-Boot is implemented in C (and to some small parts
3101 in Assembler); no C++ is used, so please do not use C++ style
3102 comments (//) in your code.
3104 Please also stick to the following formatting rules:
3105 - remove any trailing white space
3106 - use TAB characters for indentation, not spaces
3107 - make sure NOT to use DOS '\r\n' line feeds
3108 - do not add more than 2 empty lines to source files
3109 - do not add trailing empty lines to source files
3111 Submissions which do not conform to the standards may be returned
3112 with a request to reformat the changes.
3118 Since the number of patches for U-Boot is growing, we need to
3119 establish some rules. Submissions which do not conform to these rules
3120 may be rejected, even when they contain important and valuable stuff.
3123 When you send a patch, please include the following information with
3126 * For bug fixes: a description of the bug and how your patch fixes
3127 this bug. Please try to include a way of demonstrating that the
3128 patch actually fixes something.
3130 * For new features: a description of the feature and your
3133 * A CHANGELOG entry as plaintext (separate from the patch)
3135 * For major contributions, your entry to the CREDITS file
3137 * When you add support for a new board, don't forget to add this
3138 board to the MAKEALL script, too.
3140 * If your patch adds new configuration options, don't forget to
3141 document these in the README file.
3143 * The patch itself. If you are accessing the CVS repository use "cvs
3144 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3145 version of diff does not support these options, then get the latest
3146 version of GNU diff.
3148 The current directory when running this command shall be the top
3149 level directory of the U-Boot source tree, or it's parent directory
3150 (i. e. please make sure that your patch includes sufficient
3151 directory information for the affected files).
3153 We accept patches as plain text, MIME attachments or as uuencoded
3156 * If one logical set of modifications affects or creates several
3157 files, all these changes shall be submitted in a SINGLE patch file.
3159 * Changesets that contain different, unrelated modifications shall be
3160 submitted as SEPARATE patches, one patch per changeset.
3165 * Before sending the patch, run the MAKEALL script on your patched
3166 source tree and make sure that no errors or warnings are reported
3167 for any of the boards.
3169 * Keep your modifications to the necessary minimum: A patch
3170 containing several unrelated changes or arbitrary reformats will be
3171 returned with a request to re-formatting / split it.
3173 * If you modify existing code, make sure that your new code does not
3174 add to the memory footprint of the code ;-) Small is beautiful!
3175 When adding new features, these should compile conditionally only
3176 (using #ifdef), and the resulting code with the new feature
3177 disabled must not need more memory than the old code without your
projects / platform / kernel / u-boot.git / blob