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wdenkc6097192002-11-03 00:24:07 +00001#
2# (C) Copyright 2000 - 2002
3# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4#
5# See file CREDITS for list of people who contributed to this
6# project.
7#
8# This program is free software; you can redistribute it and/or
9# modify it under the terms of the GNU General Public License as
10# published by the Free Software Foundation; either version 2 of
11# the License, or (at your option) any later version.
12#
13# This program is distributed in the hope that it will be useful,
14# but WITHOUT ANY WARRANTY; without even the implied warranty of
15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16# GNU General Public License for more details.
17#
18# You should have received a copy of the GNU General Public License
19# along with this program; if not, write to the Free Software
20# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21# MA 02111-1307 USA
22#
23
24Summary:
25========
26
wdenk24ee89b2002-11-03 17:56:27 +000027This directory contains the source code for U-Boot, a boot loader for
28Embedded boards based on PowerPC and ARM processors, which can be
29installed in a boot ROM and used to initialize and test the hardware
30or to download and run application code.
wdenkc6097192002-11-03 00:24:07 +000031
32The development of U-Boot is closely related to Linux: some parts of
wdenk24ee89b2002-11-03 17:56:27 +000033the source code originate in the Linux source tree, we have some
34header files in common, and special provision has been made to
wdenkc6097192002-11-03 00:24:07 +000035support booting of Linux images.
36
37Some attention has been paid to make this software easily
38configurable and extendable. For instance, all monitor commands are
39implemented with the same call interface, so that it's very easy to
40add new commands. Also, instead of permanently adding rarely used
41code (for instance hardware test utilities) to the monitor, you can
42load and run it dynamically.
43
44
45Status:
46=======
47
48In general, all boards for which a configuration option exists in the
wdenk24ee89b2002-11-03 17:56:27 +000049Makefile have been tested to some extent and can be considered
wdenkc6097192002-11-03 00:24:07 +000050"working". In fact, many of them are used in production systems.
51
wdenk24ee89b2002-11-03 17:56:27 +000052In case of problems see the CHANGELOG and CREDITS files to find out
wdenkc6097192002-11-03 00:24:07 +000053who contributed the specific port.
54
wdenkc6097192002-11-03 00:24:07 +000055
56Where to get help:
57==================
58
wdenk24ee89b2002-11-03 17:56:27 +000059In case you have questions about, problems with or contributions for
60U-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
62previous traffic on the mailing list - please search the archive
wdenkc6097192002-11-03 00:24:07 +000063before asking FAQ's. Please see
64http://lists.sourceforge.net/lists/listinfo/u-boot-users/
65
66
67Where we come from:
68===================
69
70- start from 8xxrom sources
wdenk24ee89b2002-11-03 17:56:27 +000071- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
wdenkc6097192002-11-03 00:24:07 +000072- clean up code
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
77 * S-Record download
78 * network boot
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
wdenk24ee89b2002-11-03 17:56:27 +000080- create ARMBoot project (http://sourceforge.net/projects/armboot)
wdenkc6097192002-11-03 00:24:07 +000081- add other CPU families (starting with ARM)
wdenk24ee89b2002-11-03 17:56:27 +000082- create U-Boot project (http://sourceforge.net/projects/u-boot)
83
84
85Names and Spelling:
86===================
87
88The "official" name of this project is "Das U-Boot". The spelling
89"U-Boot" shall be used in all written text (documentation, comments
90in source files etc.). Example:
91
92 This is the README file for the U-Boot project.
93
94File names etc. shall be based on the string "u-boot". Examples:
95
96 include/asm-ppc/u-boot.h
97
98 #include <asm/u-boot.h>
99
100Variable names, preprocessor constants etc. shall be either based on
101the string "u_boot" or on "U_BOOT". Example:
102
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
wdenkc6097192002-11-03 00:24:07 +0000105
106
107Directory Hierarchy:
108====================
109
110- board Board dependend files
111- common Misc architecture independend functions
112- cpu CPU specific files
113- disk Code for disk drive partition handling
114- doc Documentation (don't expect too much)
115- drivers Common used device drivers
116- dtt Digital Thermometer and Thermostat drivers
117- examples Example code for standalone applications, etc.
118- include Header Files
119- disk Harddisk interface code
120- net Networking code
121- ppc Files generic to PowerPC architecture
122- post Power On Self Test
123- post/arch Symlink to architecture specific Power On Self Test
124- post/arch-ppc PowerPC architecture specific Power On Self Test
125- post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test
126- post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test
127- rtc Real Time Clock drivers
128- tools Tools to build S-Record or U-Boot images, etc.
129
130- cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
131- cpu/mpc8xx Files specific to Motorola MPC8xx CPUs
132- cpu/mpc824x Files specific to Motorola MPC824x CPUs
133- cpu/mpc8260 Files specific to Motorola MPC8260 CPU
134- cpu/ppc4xx Files specific to IBM 4xx CPUs
135
136- board/RPXClassic
137 Files specific to RPXClassic boards
138- board/RPXlite Files specific to RPXlite boards
139- board/c2mon Files specific to c2mon boards
140- board/cogent Files specific to Cogent boards
141 (need further configuration)
142 Files specific to CPCIISER4 boards
143- board/cpu86 Files specific to CPU86 boards
144- board/cray/ Files specific to boards manufactured by Cray
145- board/cray/L1 Files specific to L1 boards
146- board/cu824 Files specific to CU824 boards
147- board/ebony Files specific to IBM Ebony board
148- board/eric Files specific to ERIC boards
149- board/esd/ Files specific to boards manufactured by ESD
150- board/esd/adciop Files specific to ADCIOP boards
151- board/esd/ar405 Files specific to AR405 boards
152- board/esd/canbt Files specific to CANBT boards
153- board/esd/cpci405 Files specific to CPCI405 boards
154- board/esd/cpciiser4 Files specific to CPCIISER4 boards
155- board/esd/common Common files for ESD boards
156- board/esd/dasa_sim Files specific to DASA_SIM boards
157- board/esd/du405 Files specific to DU405 boards
158- board/esd/ocrtc Files specific to OCRTC boards
159- board/esd/pci405 Files specific to PCI405 boards
160- board/esteem192e
161 Files specific to ESTEEM192E boards
162- board/etx094 Files specific to ETX_094 boards
163- board/evb64260
164 Files specific to EVB64260 boards
165- board/fads Files specific to FADS boards
166- board/flagadm Files specific to FLAGADM boards
167- board/gen860t Files specific to GEN860T boards
168- board/genietv Files specific to GENIETV boards
169- board/gth Files specific to GTH boards
170- board/hermes Files specific to HERMES boards
171- board/hymod Files specific to HYMOD boards
172- board/icu862 Files specific to ICU862 boards
173- board/ip860 Files specific to IP860 boards
174- board/iphase4539
175 Files specific to Interphase4539 boards
176- board/ivm Files specific to IVMS8/IVML24 boards
177- board/lantec Files specific to LANTEC boards
178- board/lwmon Files specific to LWMON boards
179- board/mbx8xx Files specific to MBX boards
180- board/mpc8260ads
181 Files specific to MMPC8260ADS boards
182- board/mpl/ Files specific to boards manufactured by MPL
183- board/mpl/common Common files for MPL boards
184- board/mpl/pip405 Files specific to PIP405 boards
185- board/mpl/mip405 Files specific to MIP405 boards
186- board/musenki Files specific to MUSEKNI boards
187- board/mvs1 Files specific to MVS1 boards
188- board/nx823 Files specific to NX823 boards
189- board/oxc Files specific to OXC boards
190- board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
191- board/pm826 Files specific to PM826 boards
192- board/ppmc8260
193 Files specific to PPMC8260 boards
194- board/rpxsuper
195 Files specific to RPXsuper boards
196- board/rsdproto
197 Files specific to RSDproto boards
198- board/sandpoint
199 Files specific to Sandpoint boards
200- board/sbc8260 Files specific to SBC8260 boards
201- board/sacsng Files specific to SACSng boards
202- board/siemens Files specific to boards manufactured by Siemens AG
203- board/siemens/CCM Files specific to CCM boards
204- board/siemens/IAD210 Files specific to IAD210 boards
205- board/siemens/SCM Files specific to SCM boards
206- board/siemens/pcu_e Files specific to PCU_E boards
207- board/sixnet Files specific to SIXNET boards
208- board/spd8xx Files specific to SPD8xxTS boards
209- board/tqm8260 Files specific to TQM8260 boards
210- board/tqm8xx Files specific to TQM8xxL boards
211- board/w7o Files specific to W7O boards
212- board/walnut405
213 Files specific to Walnut405 boards
214- board/westel/ Files specific to boards manufactured by Westel Wireless
215- board/westel/amx860 Files specific to AMX860 boards
216- board/utx8245 Files specific to UTX8245 boards
217
218Software Configuration:
219=======================
220
221Configuration is usually done using C preprocessor defines; the
222rationale behind that is to avoid dead code whenever possible.
223
224There are two classes of configuration variables:
225
226* Configuration _OPTIONS_:
227 These are selectable by the user and have names beginning with
228 "CONFIG_".
229
230* Configuration _SETTINGS_:
231 These depend on the hardware etc. and should not be meddled with if
232 you don't know what you're doing; they have names beginning with
233 "CFG_".
234
235Later we will add a configuration tool - probably similar to or even
236identical to what's used for the Linux kernel. Right now, we have to
237do the configuration by hand, which means creating some symbolic
238links and editing some configuration files. We use the TQM8xxL boards
239as an example here.
240
241
242Selection of Processor Architecture and Board Type:
243---------------------------------------------------
244
245For all supported boards there are ready-to-use default
246configurations available; just type "make <board_name>_config".
247
248Example: For a TQM823L module type:
249
250 cd u-boot
251 make TQM823L_config
252
253For the Cogent platform, you need to specify the cpu type as well;
254e.g. "make cogent_mpc8xx_config". And also configure the cogent
255directory according to the instructions in cogent/README.
256
257
258Configuration Options:
259----------------------
260
261Configuration depends on the combination of board and CPU type; all
262such information is kept in a configuration file
263"include/configs/<board_name>.h".
264
265Example: For a TQM823L module, all configuration settings are in
266"include/configs/TQM823L.h".
267
268
wdenk7f6c2cb2002-11-10 22:06:23 +0000269Many of the options are named exactly as the corresponding Linux
270kernel configuration options. The intention is to make it easier to
271build a config tool - later.
272
273
wdenkc6097192002-11-03 00:24:07 +0000274The following options need to be configured:
275
276- CPU Type: Define exactly one of
277
278 PowerPC based CPUs:
279 -------------------
280 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
281 or CONFIG_MPC824X, CONFIG_MPC8260
282 or CONFIG_IOP480
283 or CONFIG_405GP
284 or CONFIG_440
285 or CONFIG_MPC74xx
286
287 ARM based CPUs:
288 ---------------
289 CONFIG_SA1110
290 CONFIG_ARM7
291 CONFIG_PXA250
292
293
294- Board Type: Define exactly one of
295
296 PowerPC based boards:
297 ---------------------
298
299 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
300 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
301 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
302 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
303 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
304 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
305 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
306 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
307 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
308 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
309 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
310 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
311 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
312 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
313 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
314 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
315 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
316 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
317 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
318 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
319 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
320 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
321 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
322 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
323 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
324 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
325 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
326 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
327 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
wdenk384ae022002-11-05 00:17:55 +0000328 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L
wdenkc6097192002-11-03 00:24:07 +0000329
330 ARM based boards:
331 -----------------
332
333 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
334 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
335 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
336 CONFIG_TRAB
337
338
339- CPU Module Type: (if CONFIG_COGENT is defined)
340 Define exactly one of
341 CONFIG_CMA286_60_OLD
342--- FIXME --- not tested yet:
343 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
344 CONFIG_CMA287_23, CONFIG_CMA287_50
345
346- Motherboard Type: (if CONFIG_COGENT is defined)
347 Define exactly one of
348 CONFIG_CMA101, CONFIG_CMA102
349
350- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
351 Define one or more of
352 CONFIG_CMA302
353
354- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
355 Define one or more of
356 CONFIG_LCD_HEARTBEAT - update a character position on
357 the lcd display every second with
358 a "rotator" |\-/|\-/
359
360- MPC824X Family Member (if CONFIG_MPC824X is defined)
361 Define exactly one of
362 CONFIG_MPC8240, CONFIG_MPC8245
363
364- 8xx CPU Options: (if using an 8xx cpu)
365 Define one or more of
366 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
367 no 32KHz reference PIT/RTC clock
368
369- Clock Interface:
370 CONFIG_CLOCKS_IN_MHZ
371
372 U-Boot stores all clock information in Hz
373 internally. For binary compatibility with older Linux
374 kernels (which expect the clocks passed in the
375 bd_info data to be in MHz) the environment variable
376 "clocks_in_mhz" can be defined so that U-Boot
377 converts clock data to MHZ before passing it to the
378 Linux kernel.
379
380 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
381 "clocks_in_mhz=1" is automatically included in the
382 default environment.
383
384- Console Interface:
385 Depending on board, define exactly one serial port
386 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
387 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
388 console by defining CONFIG_8xx_CONS_NONE
389
390 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
391 port routines must be defined elsewhere
392 (i.e. serial_init(), serial_getc(), ...)
393
394 CONFIG_CFB_CONSOLE
395 Enables console device for a color framebuffer. Needs following
396 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
397 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
398 (default big endian)
399 VIDEO_HW_RECTFILL graphic chip supports
400 rectangle fill
401 (cf. smiLynxEM)
402 VIDEO_HW_BITBLT graphic chip supports
403 bit-blit (cf. smiLynxEM)
404 VIDEO_VISIBLE_COLS visible pixel columns
405 (cols=pitch)
406 VIDEO_VISIBLE_ROWS visible pixel rows
407 VIDEO_PIXEL_SIZE bytes per pixel
408 VIDEO_DATA_FORMAT graphic data format
409 (0-5, cf. cfb_console.c)
410 VIDEO_FB_ADRS framebuffer address
411 VIDEO_KBD_INIT_FCT keyboard int fct
412 (i.e. i8042_kbd_init())
413 VIDEO_TSTC_FCT test char fct
414 (i.e. i8042_tstc)
415 VIDEO_GETC_FCT get char fct
416 (i.e. i8042_getc)
417 CONFIG_CONSOLE_CURSOR cursor drawing on/off
418 (requires blink timer
419 cf. i8042.c)
420 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
421 CONFIG_CONSOLE_TIME display time/date info in
422 upper right corner
423 (requires CFG_CMD_DATE)
424 CONFIG_VIDEO_LOGO display Linux logo in
425 upper left corner
wdenka6c7ad22002-12-03 21:28:10 +0000426 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
427 linux_logo.h for logo.
428 Requires CONFIG_VIDEO_LOGO
wdenkc6097192002-11-03 00:24:07 +0000429 CONFIG_CONSOLE_EXTRA_INFO
430 addional board info beside
431 the logo
432
433 When CONFIG_CFB_CONSOLE is defined, video console is
434 default i/o. Serial console can be forced with
435 environment 'console=serial'.
436
437- Console Baudrate:
438 CONFIG_BAUDRATE - in bps
439 Select one of the baudrates listed in
440 CFG_BAUDRATE_TABLE, see below.
441
442- Interrupt driven serial port input:
443 CONFIG_SERIAL_SOFTWARE_FIFO
444
445 PPC405GP only.
446 Use an interrupt handler for receiving data on the
447 serial port. It also enables using hardware handshake
448 (RTS/CTS) and UART's built-in FIFO. Set the number of
449 bytes the interrupt driven input buffer should have.
450
451 Set to 0 to disable this feature (this is the default).
452 This will also disable hardware handshake.
453
454- Boot Delay: CONFIG_BOOTDELAY - in seconds
455 Delay before automatically booting the default image;
456 set to -1 to disable autoboot.
457
458 See doc/README.autoboot for these options that
459 work with CONFIG_BOOTDELAY. None are required.
460 CONFIG_BOOT_RETRY_TIME
461 CONFIG_BOOT_RETRY_MIN
462 CONFIG_AUTOBOOT_KEYED
463 CONFIG_AUTOBOOT_PROMPT
464 CONFIG_AUTOBOOT_DELAY_STR
465 CONFIG_AUTOBOOT_STOP_STR
466 CONFIG_AUTOBOOT_DELAY_STR2
467 CONFIG_AUTOBOOT_STOP_STR2
468 CONFIG_ZERO_BOOTDELAY_CHECK
469 CONFIG_RESET_TO_RETRY
470
471- Autoboot Command:
472 CONFIG_BOOTCOMMAND
473 Only needed when CONFIG_BOOTDELAY is enabled;
474 define a command string that is automatically executed
475 when no character is read on the console interface
476 within "Boot Delay" after reset.
477
478 CONFIG_BOOTARGS
479 This can be used to pass arguments to the bootm
480 command. The value of CONFIG_BOOTARGS goes into the
481 environment value "bootargs".
482
483 CONFIG_RAMBOOT and CONFIG_NFSBOOT
484 The value of these goes into the environment as
485 "ramboot" and "nfsboot" respectively, and can be used
486 as a convenience, when switching between booting from
487 ram and nfs.
488
489- Pre-Boot Commands:
490 CONFIG_PREBOOT
491
492 When this option is #defined, the existence of the
493 environment variable "preboot" will be checked
494 immediately before starting the CONFIG_BOOTDELAY
495 countdown and/or running the auto-boot command resp.
496 entering interactive mode.
497
498 This feature is especially useful when "preboot" is
499 automatically generated or modified. For an example
500 see the LWMON board specific code: here "preboot" is
501 modified when the user holds down a certain
502 combination of keys on the (special) keyboard when
503 booting the systems
504
505- Serial Download Echo Mode:
506 CONFIG_LOADS_ECHO
507 If defined to 1, all characters received during a
508 serial download (using the "loads" command) are
509 echoed back. This might be needed by some terminal
510 emulations (like "cu"), but may as well just take
511 time on others. This setting #define's the initial
512 value of the "loads_echo" environment variable.
513
514- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
515 CONFIG_KGDB_BAUDRATE
516 Select one of the baudrates listed in
517 CFG_BAUDRATE_TABLE, see below.
518
519- Monitor Functions:
520 CONFIG_COMMANDS
521 Most monitor functions can be selected (or
522 de-selected) by adjusting the definition of
523 CONFIG_COMMANDS; to select individual functions,
524 #define CONFIG_COMMANDS by "OR"ing any of the
525 following values:
526
527 #define enables commands:
528 -------------------------
529 CFG_CMD_ASKENV * ask for env variable
530 CFG_CMD_BDI bdinfo
531 CFG_CMD_BEDBUG Include BedBug Debugger
532 CFG_CMD_BOOTD bootd
533 CFG_CMD_CACHE icache, dcache
534 CFG_CMD_CONSOLE coninfo
535 CFG_CMD_DATE * support for RTC, date/time...
536 CFG_CMD_DHCP DHCP support
537 CFG_CMD_ECHO * echo arguments
538 CFG_CMD_EEPROM * EEPROM read/write support
539 CFG_CMD_ELF bootelf, bootvx
540 CFG_CMD_ENV saveenv
541 CFG_CMD_FDC * Floppy Disk Support
wdenk2262cfe2002-11-18 00:14:45 +0000542 CFG_CMD_FDOS * Dos diskette Support
wdenkc6097192002-11-03 00:24:07 +0000543 CFG_CMD_FLASH flinfo, erase, protect
544 CFG_CMD_FPGA FPGA device initialization support
545 CFG_CMD_I2C * I2C serial bus support
546 CFG_CMD_IDE * IDE harddisk support
547 CFG_CMD_IMI iminfo
548 CFG_CMD_IMMAP * IMMR dump support
549 CFG_CMD_IRQ * irqinfo
550 CFG_CMD_KGDB * kgdb
551 CFG_CMD_LOADB loadb
552 CFG_CMD_LOADS loads
553 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
554 loop, mtest
555 CFG_CMD_MII MII utility commands
556 CFG_CMD_NET bootp, tftpboot, rarpboot
557 CFG_CMD_PCI * pciinfo
558 CFG_CMD_PCMCIA * PCMCIA support
559 CFG_CMD_REGINFO * Register dump
560 CFG_CMD_RUN run command in env variable
561 CFG_CMD_SCSI * SCSI Support
562 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
563 CFG_CMD_SPI * SPI serial bus support
564 CFG_CMD_USB * USB support
565 CFG_CMD_BSP * Board SPecific functions
566 -----------------------------------------------
567 CFG_CMD_ALL all
568
569 CFG_CMD_DFL Default configuration; at the moment
570 this is includes all commands, except
571 the ones marked with "*" in the list
572 above.
573
574 If you don't define CONFIG_COMMANDS it defaults to
575 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
576 override the default settings in the respective
577 include file.
578
579 EXAMPLE: If you want all functions except of network
580 support you can write:
581
582 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
583
584
585 Note: Don't enable the "icache" and "dcache" commands
586 (configuration option CFG_CMD_CACHE) unless you know
587 what you (and your U-Boot users) are doing. Data
588 cache cannot be enabled on systems like the 8xx or
589 8260 (where accesses to the IMMR region must be
590 uncached), and it cannot be disabled on all other
591 systems where we (mis-) use the data cache to hold an
592 initial stack and some data.
593
594
595 XXX - this list needs to get updated!
596
597- Watchdog:
598 CONFIG_WATCHDOG
599 If this variable is defined, it enables watchdog
600 support. There must support in the platform specific
601 code for a watchdog. For the 8xx and 8260 CPUs, the
602 SIU Watchdog feature is enabled in the SYPCR
603 register.
604
605- Real-Time Clock:
606
607 When CFG_CMD_DATE is selected, the type of the RTC
608 has to be selected, too. Define exactly one of the
609 following options:
610
611 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
612 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
613 CONFIG_RTC_MC146818 - use MC146818 RTC
614 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
615
616- Timestamp Support:
617
618 When CONFIG_TIMESTAMP is selected, the timestamp
619 (date and time) of an image is printed by image
620 commands like bootm or iminfo. This option is
621 automatically enabled when you select CFG_CMD_DATE .
622
623- Partition Support:
624 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
625 and/or CONFIG_ISO_PARTITION
626
627 If IDE or SCSI support is enabled (CFG_CMD_IDE or
628 CFG_CMD_SCSI) you must configure support for at least
629 one partition type as well.
630
631- IDE Reset method:
632 CONFIG_IDE_RESET_ROUTINE
633
634 Set this to define that instead of a reset Pin, the
635 routine ide_set_reset(int idereset) will be used.
636
637- ATAPI Support:
638 CONFIG_ATAPI
639
640 Set this to enable ATAPI support.
641
642- SCSI Support:
643 At the moment only there is only support for the
644 SYM53C8XX SCSI controller; define
645 CONFIG_SCSI_SYM53C8XX to enable it.
646
647 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
648 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
649 CFG_SCSI_MAX_LUN] can be adjusted to define the
650 maximum numbers of LUNs, SCSI ID's and target
651 devices.
652 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
653
654- NETWORK Support (PCI):
655 CONFIG_EEPRO100
656 Support for Intel 82557/82559/82559ER chips.
657 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
658 write routine for first time initialisation.
659
660 CONFIG_TULIP
661 Support for Digital 2114x chips.
662 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
663 modem chip initialisation (KS8761/QS6611).
664
665 CONFIG_NATSEMI
666 Support for National dp83815 chips.
667
668 CONFIG_NS8382X
669 Support for National dp8382[01] gigabit chips.
670
671- USB Support:
672 At the moment only the UHCI host controller is
673 supported (PIP405, MIP405); define
674 CONFIG_USB_UHCI to enable it.
675 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
676 end define CONFIG_USB_STORAGE to enable the USB
677 storage devices.
678 Note:
679 Supported are USB Keyboards and USB Floppy drives
680 (TEAC FD-05PUB).
681
682- Keyboard Support:
683 CONFIG_ISA_KEYBOARD
684
685 Define this to enable standard (PC-Style) keyboard
686 support
687
688 CONFIG_I8042_KBD
689 Standard PC keyboard driver with US (is default) and
690 GERMAN key layout (switch via environment 'keymap=de') support.
691 Export function i8042_kbd_init, i8042_tstc and i8042_getc
692 for cfb_console. Supports cursor blinking.
693
694- Video support:
695 CONFIG_VIDEO
696
697 Define this to enable video support (for output to
698 video).
699
700 CONFIG_VIDEO_CT69000
701
702 Enable Chips & Technologies 69000 Video chip
703
704 CONFIG_VIDEO_SMI_LYNXEM
705 Enable Silicon Motion SMI 712/710/810 Video chip
706 Videomode are selected via environment 'videomode' with
707 standard LiLo mode numbers.
708 Following modes are supported (* is default):
709
710 800x600 1024x768 1280x1024
711 256 (8bit) 303* 305 307
712 65536 (16bit) 314 317 31a
713 16,7 Mill (24bit) 315 318 31b
714 (i.e. setenv videomode 317; saveenv; reset;)
715
wdenka6c7ad22002-12-03 21:28:10 +0000716 CONFIG_VIDEO_SED13806
717 Enable Epson SED13806 driver. This driver supports 8bpp
718 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
719 or CONFIG_VIDEO_SED13806_16BPP
720
721
wdenkc6097192002-11-03 00:24:07 +0000722- LCD Support: CONFIG_LCD
723
724 Define this to enable LCD support (for output to LCD
725 display); also select one of the supported displays
726 by defining one of these:
727
728 CONFIG_NEC_NL6648AC33:
729
730 NEC NL6648AC33-18. Active, color, single scan.
731
732 CONFIG_NEC_NL6648BC20
733
734 NEC NL6648BC20-08. 6.5", 640x480.
735 Active, color, single scan.
736
737 CONFIG_SHARP_16x9
738
739 Sharp 320x240. Active, color, single scan.
740 It isn't 16x9, and I am not sure what it is.
741
742 CONFIG_SHARP_LQ64D341
743
744 Sharp LQ64D341 display, 640x480.
745 Active, color, single scan.
746
747 CONFIG_HLD1045
748
749 HLD1045 display, 640x480.
750 Active, color, single scan.
751
752 CONFIG_OPTREX_BW
753
754 Optrex CBL50840-2 NF-FW 99 22 M5
755 or
756 Hitachi LMG6912RPFC-00T
757 or
758 Hitachi SP14Q002
759
760 320x240. Black & white.
761
762 Normally display is black on white background; define
763 CFG_WHITE_ON_BLACK to get it inverted.
764
765- Ethernet address:
766 CONFIG_ETHADDR
767 CONFIG_ETH2ADDR
768 CONFIG_ETH3ADDR
769
770 Define a default value for ethernet address to use
771 for the respective ethernet interface, in case this
772 is not determined automatically.
773
774- IP address:
775 CONFIG_IPADDR
776
777 Define a default value for the IP address to use for
778 the default ethernet interface, in case this is not
779 determined through e.g. bootp.
780
781- Server IP address:
782 CONFIG_SERVERIP
783
784 Defines a default value for theIP address of a TFTP
785 server to contact when using the "tftboot" command.
786
787- BOOTP Recovery Mode:
788 CONFIG_BOOTP_RANDOM_DELAY
789
790 If you have many targets in a network that try to
791 boot using BOOTP, you may want to avoid that all
792 systems send out BOOTP requests at precisely the same
793 moment (which would happen for instance at recovery
794 from a power failure, when all systems will try to
795 boot, thus flooding the BOOTP server. Defining
796 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
797 inserted before sending out BOOTP requests. The
798 following delays are insterted then:
799
800 1st BOOTP request: delay 0 ... 1 sec
801 2nd BOOTP request: delay 0 ... 2 sec
802 3rd BOOTP request: delay 0 ... 4 sec
803 4th and following
804 BOOTP requests: delay 0 ... 8 sec
805
806- Status LED: CONFIG_STATUS_LED
807
808 Several configurations allow to display the current
809 status using a LED. For instance, the LED will blink
810 fast while running U-Boot code, stop blinking as
811 soon as a reply to a BOOTP request was received, and
812 start blinking slow once the Linux kernel is running
813 (supported by a status LED driver in the Linux
814 kernel). Defining CONFIG_STATUS_LED enables this
815 feature in U-Boot.
816
817- CAN Support: CONFIG_CAN_DRIVER
818
819 Defining CONFIG_CAN_DRIVER enables CAN driver support
820 on those systems that support this (optional)
821 feature, like the TQM8xxL modules.
822
823- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
824
825 Enables I2C serial bus commands. If this is selected,
826 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
827 to include the appropriate I2C driver.
828
829 See also: common/cmd_i2c.c for a description of the
830 command line interface.
831
832
833 CONFIG_HARD_I2C
834
835 Selects the CPM hardware driver for I2C.
836
837 CONFIG_SOFT_I2C
838
839 Use software (aka bit-banging) driver instead of CPM
840 or similar hardware support for I2C. This is configured
841 via the following defines.
842
843 I2C_INIT
844
845 (Optional). Any commands necessary to enable I2C
846 controller or configure ports.
847
848 I2C_PORT
849
850 (Only for MPC8260 CPU). The I/O port to use (the code
851 assumes both bits are on the same port). Valid values
852 are 0..3 for ports A..D.
853
854 I2C_ACTIVE
855
856 The code necessary to make the I2C data line active
857 (driven). If the data line is open collector, this
858 define can be null.
859
860 I2C_TRISTATE
861
862 The code necessary to make the I2C data line tri-stated
863 (inactive). If the data line is open collector, this
864 define can be null.
865
866 I2C_READ
867
868 Code that returns TRUE if the I2C data line is high,
869 FALSE if it is low.
870
871 I2C_SDA(bit)
872
873 If <bit> is TRUE, sets the I2C data line high. If it
874 is FALSE, it clears it (low).
875
876 I2C_SCL(bit)
877
878 If <bit> is TRUE, sets the I2C clock line high. If it
879 is FALSE, it clears it (low).
880
881 I2C_DELAY
882
883 This delay is invoked four times per clock cycle so this
884 controls the rate of data transfer. The data rate thus
885 is 1 / (I2C_DELAY * 4).
886
887- SPI Support: CONFIG_SPI
888
889 Enables SPI driver (so far only tested with
890 SPI EEPROM, also an instance works with Crystal A/D and
891 D/As on the SACSng board)
892
893 CONFIG_SPI_X
894
895 Enables extended (16-bit) SPI EEPROM addressing.
896 (symmetrical to CONFIG_I2C_X)
897
898 CONFIG_SOFT_SPI
899
900 Enables a software (bit-bang) SPI driver rather than
901 using hardware support. This is a general purpose
902 driver that only requires three general I/O port pins
903 (two outputs, one input) to function. If this is
904 defined, the board configuration must define several
905 SPI configuration items (port pins to use, etc). For
906 an example, see include/configs/sacsng.h.
907
908- FPGA Support: CONFIG_FPGA_COUNT
909
910 Specify the number of FPGA devices to support.
911
912 CONFIG_FPGA
913
914 Used to specify the types of FPGA devices. For
915 example,
916 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
917
918 CFG_FPGA_PROG_FEEDBACK
919
920 Enable printing of hash marks during FPGA
921 configuration.
922
923 CFG_FPGA_CHECK_BUSY
924
925 Enable checks on FPGA configuration interface busy
926 status by the configuration function. This option
927 will require a board or device specific function to
928 be written.
929
930 CONFIG_FPGA_DELAY
931
932 If defined, a function that provides delays in the
933 FPGA configuration driver.
934
935 CFG_FPGA_CHECK_CTRLC
936
937 Allow Control-C to interrupt FPGA configuration
938
939 CFG_FPGA_CHECK_ERROR
940
941 Check for configuration errors during FPGA bitfile
942 loading. For example, abort during Virtex II
943 configuration if the INIT_B line goes low (which
944 indicated a CRC error).
945
946 CFG_FPGA_WAIT_INIT
947
948 Maximum time to wait for the INIT_B line to deassert
949 after PROB_B has been deasserted during a Virtex II
950 FPGA configuration sequence. The default time is 500 mS.
951
952 CFG_FPGA_WAIT_BUSY
953
954 Maximum time to wait for BUSY to deassert during
955 Virtex II FPGA configuration. The default is 5 mS.
956
957 CFG_FPGA_WAIT_CONFIG
958
959 Time to wait after FPGA configuration. The default is
960 200 mS.
961
962- FPGA Support: CONFIG_FPGA_COUNT
963
964 Specify the number of FPGA devices to support.
965
966 CONFIG_FPGA
967
968 Used to specify the types of FPGA devices. For example,
969 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
970
971 CFG_FPGA_PROG_FEEDBACK
972
973 Enable printing of hash marks during FPGA configuration.
974
975 CFG_FPGA_CHECK_BUSY
976
977 Enable checks on FPGA configuration interface busy
978 status by the configuration function. This option
979 will require a board or device specific function to
980 be written.
981
982 CONFIG_FPGA_DELAY
983
984 If defined, a function that provides delays in the FPGA
985 configuration driver.
986
987 CFG_FPGA_CHECK_CTRLC
988 Allow Control-C to interrupt FPGA configuration
989
990 CFG_FPGA_CHECK_ERROR
991
992 Check for configuration errors during FPGA bitfile
993 loading. For example, abort during Virtex II
994 configuration if the INIT_B line goes low (which
995 indicated a CRC error).
996
997 CFG_FPGA_WAIT_INIT
998
999 Maximum time to wait for the INIT_B line to deassert
1000 after PROB_B has been deasserted during a Virtex II
1001 FPGA configuration sequence. The default time is 500
1002 mS.
1003
1004 CFG_FPGA_WAIT_BUSY
1005
1006 Maximum time to wait for BUSY to deassert during
1007 Virtex II FPGA configuration. The default is 5 mS.
1008
1009 CFG_FPGA_WAIT_CONFIG
1010
1011 Time to wait after FPGA configuration. The default is
1012 200 mS.
1013
1014- Configuration Management:
1015 CONFIG_IDENT_STRING
1016
1017 If defined, this string will be added to the U-Boot
1018 version information (U_BOOT_VERSION)
1019
1020- Vendor Parameter Protection:
1021
1022 U-Boot considers the values of the environment
1023 variables "serial#" (Board Serial Number) and
1024 "ethaddr" (Ethernet Address) to bb parameters that
1025 are set once by the board vendor / manufacturer, and
1026 protects these variables from casual modification by
1027 the user. Once set, these variables are read-only,
1028 and write or delete attempts are rejected. You can
1029 change this behviour:
1030
1031 If CONFIG_ENV_OVERWRITE is #defined in your config
1032 file, the write protection for vendor parameters is
1033 completely disabled. Anybody can change or delte
1034 these parameters.
1035
1036 Alternatively, if you #define _both_ CONFIG_ETHADDR
1037 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1038 ethernet address is installed in the environment,
1039 which can be changed exactly ONCE by the user. [The
1040 serial# is unaffected by this, i. e. it remains
1041 read-only.]
1042
1043- Protected RAM:
1044 CONFIG_PRAM
1045
1046 Define this variable to enable the reservation of
1047 "protected RAM", i. e. RAM which is not overwritten
1048 by U-Boot. Define CONFIG_PRAM to hold the number of
1049 kB you want to reserve for pRAM. You can overwrite
1050 this default value by defining an environment
1051 variable "pram" to the number of kB you want to
1052 reserve. Note that the board info structure will
1053 still show the full amount of RAM. If pRAM is
1054 reserved, a new environment variable "mem" will
1055 automatically be defined to hold the amount of
1056 remaining RAM in a form that can be passed as boot
1057 argument to Linux, for instance like that:
1058
1059 setenv bootargs ... mem=\$(mem)
1060 saveenv
1061
1062 This way you can tell Linux not to use this memory,
1063 either, which results in a memory region that will
1064 not be affected by reboots.
1065
1066 *WARNING* If your board configuration uses automatic
1067 detection of the RAM size, you must make sure that
1068 this memory test is non-destructive. So far, the
1069 following board configurations are known to be
1070 "pRAM-clean":
1071
1072 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1073 HERMES, IP860, RPXlite, LWMON, LANTEC,
1074 PCU_E, FLAGADM, TQM8260
1075
1076- Error Recovery:
1077 CONFIG_PANIC_HANG
1078
1079 Define this variable to stop the system in case of a
1080 fatal error, so that you have to reset it manually.
1081 This is probably NOT a good idea for an embedded
1082 system where you want to system to reboot
1083 automatically as fast as possible, but it may be
1084 useful during development since you can try to debug
1085 the conditions that lead to the situation.
1086
1087 CONFIG_NET_RETRY_COUNT
1088
1089 This variable defines the number of retries for
1090 network operations like ARP, RARP, TFTP, or BOOTP
1091 before giving up the operation. If not defined, a
1092 default value of 5 is used.
1093
1094- Command Interpreter:
1095 CFG_HUSH_PARSER
1096
1097 Define this variable to enable the "hush" shell (from
1098 Busybox) as command line interpreter, thus enabling
1099 powerful command line syntax like
1100 if...then...else...fi conditionals or `&&' and '||'
1101 constructs ("shell scripts").
1102
1103 If undefined, you get the old, much simpler behaviour
1104 with a somewhat smaller memory footprint.
1105
1106
1107 CFG_PROMPT_HUSH_PS2
1108
1109 This defines the secondary prompt string, which is
1110 printed when the command interpreter needs more input
1111 to complete a command. Usually "> ".
1112
1113 Note:
1114
1115 In the current implementation, the local variables
1116 space and global environment variables space are
1117 separated. Local variables are those you define by
1118 simply typing like `name=value'. To access a local
1119 variable later on, you have write `$name' or
1120 `${name}'; variable directly by typing say `$name' at
1121 the command prompt.
1122
1123 Global environment variables are those you use
1124 setenv/printenv to work with. To run a command stored
1125 in such a variable, you need to use the run command,
1126 and you must not use the '$' sign to access them.
1127
1128 To store commands and special characters in a
1129 variable, please use double quotation marks
1130 surrounding the whole text of the variable, instead
1131 of the backslashes before semicolons and special
1132 symbols.
1133
1134- Default Environment
1135 CONFIG_EXTRA_ENV_SETTINGS
1136
1137 Define this to contain any number of null terminated
1138 strings (variable = value pairs) that will be part of
1139 the default enviroment compiled into the boot image.
wdenk2262cfe2002-11-18 00:14:45 +00001140
wdenkc6097192002-11-03 00:24:07 +00001141 For example, place something like this in your
1142 board's config file:
1143
1144 #define CONFIG_EXTRA_ENV_SETTINGS \
1145 "myvar1=value1\0" \
1146 "myvar2=value2\0"
1147
1148 Warning: This method is based on knowledge about the
1149 internal format how the environment is stored by the
wdenk2262cfe2002-11-18 00:14:45 +00001150 U-Boot code. This is NOT an official, exported
wdenkc6097192002-11-03 00:24:07 +00001151 interface! Although it is unlikely that this format
wdenk2262cfe2002-11-18 00:14:45 +00001152 will change soon, but there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001153 You better know what you are doing here.
1154
1155 Note: overly (ab)use of the default environment is
1156 discouraged. Make sure to check other ways to preset
1157 the environment like the autoscript function or the
1158 boot command first.
1159
1160- Show boot progress
1161 CONFIG_SHOW_BOOT_PROGRESS
1162
1163 Defining this option allows to add some board-
1164 specific code (calling a user-provided function
1165 "show_boot_progress(int)") that enables you to show
1166 the system's boot progress on some display (for
1167 example, some LED's) on your board. At the moment,
1168 the following checkpoints are implemented:
1169
1170 Arg Where When
1171 1 common/cmd_bootm.c before attempting to boot an image
1172 -1 common/cmd_bootm.c Image header has bad magic number
1173 2 common/cmd_bootm.c Image header has correct magic number
1174 -2 common/cmd_bootm.c Image header has bad checksum
1175 3 common/cmd_bootm.c Image header has correct checksum
1176 -3 common/cmd_bootm.c Image data has bad checksum
1177 4 common/cmd_bootm.c Image data has correct checksum
1178 -4 common/cmd_bootm.c Image is for unsupported architecture
1179 5 common/cmd_bootm.c Architecture check OK
1180 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1181 6 common/cmd_bootm.c Image Type check OK
1182 -6 common/cmd_bootm.c gunzip uncompression error
1183 -7 common/cmd_bootm.c Unimplemented compression type
1184 7 common/cmd_bootm.c Uncompression OK
1185 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1186 8 common/cmd_bootm.c Image Type check OK
1187 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1188 9 common/cmd_bootm.c Start initial ramdisk verification
1189 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1190 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1191 10 common/cmd_bootm.c Ramdisk header is OK
1192 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1193 11 common/cmd_bootm.c Ramdisk data has correct checksum
1194 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1195 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1196 13 common/cmd_bootm.c Start multifile image verification
1197 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1198 15 common/cmd_bootm.c All preparation done, transferring control to OS
1199
1200 -1 common/cmd_doc.c Bad usage of "doc" command
1201 -1 common/cmd_doc.c No boot device
1202 -1 common/cmd_doc.c Unknown Chip ID on boot device
1203 -1 common/cmd_doc.c Read Error on boot device
1204 -1 common/cmd_doc.c Image header has bad magic number
1205
1206 -1 common/cmd_ide.c Bad usage of "ide" command
1207 -1 common/cmd_ide.c No boot device
1208 -1 common/cmd_ide.c Unknown boot device
1209 -1 common/cmd_ide.c Unknown partition table
1210 -1 common/cmd_ide.c Invalid partition type
1211 -1 common/cmd_ide.c Read Error on boot device
1212 -1 common/cmd_ide.c Image header has bad magic number
1213
1214 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC
1215
1216
1217Modem Support:
1218--------------
1219
1220[so far only for SMDK2400 board]
1221
1222- Modem support endable:
1223 CONFIG_MODEM_SUPPORT
1224
1225- RTS/CTS Flow control enable:
1226 CONFIG_HWFLOW
1227
1228- Modem debug support:
1229 CONFIG_MODEM_SUPPORT_DEBUG
1230
1231 Enables debugging stuff (char screen[1024], dbg())
1232 for modem support. Useful only with BDI2000.
1233
1234- General:
1235
1236 In the target system modem support is enabled when a
1237 specific key (key combination) is pressed during
1238 power-on. Otherwise U-Boot will boot normally
1239 (autoboot). The key_pressed() fuction is called from
1240 board_init(). Currently key_pressed() is a dummy
1241 function, returning 1 and thus enabling modem
1242 initialization.
1243
1244 If there are no modem init strings in the
1245 environment, U-Boot proceed to autoboot; the
1246 previous output (banner, info printfs) will be
1247 supressed, though.
1248
1249 See also: doc/README.Modem
1250
1251
1252
1253
1254Configuration Settings:
1255-----------------------
1256
1257- CFG_LONGHELP: Defined when you want long help messages included;
1258 undefine this when you're short of memory.
1259
1260- CFG_PROMPT: This is what U-Boot prints on the console to
1261 prompt for user input.
1262
1263- CFG_CBSIZE: Buffer size for input from the Console
1264
1265- CFG_PBSIZE: Buffer size for Console output
1266
1267- CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1268
1269- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1270 the application (usually a Linux kernel) when it is
1271 booted
1272
1273- CFG_BAUDRATE_TABLE:
1274 List of legal baudrate settings for this board.
1275
1276- CFG_CONSOLE_INFO_QUIET
1277 Suppress display of console information at boot.
1278
1279- CFG_CONSOLE_IS_IN_ENV
1280 If the board specific function
1281 extern int overwrite_console (void);
1282 returns 1, the stdin, stderr and stdout are switched to the
1283 serial port, else the settings in the environment are used.
1284
1285- CFG_CONSOLE_OVERWRITE_ROUTINE
1286 Enable the call to overwrite_console().
1287
1288- CFG_CONSOLE_ENV_OVERWRITE
1289 Enable overwrite of previous console environment settings.
1290
1291- CFG_MEMTEST_START, CFG_MEMTEST_END:
1292 Begin and End addresses of the area used by the
1293 simple memory test.
1294
1295- CFG_ALT_MEMTEST:
1296 Enable an alternate, more extensive memory test.
1297
1298- CFG_TFTP_LOADADDR:
1299 Default load address for network file downloads
1300
1301- CFG_LOADS_BAUD_CHANGE:
1302 Enable temporary baudrate change while serial download
1303
1304- CFG_SDRAM_BASE:
1305 Physical start address of SDRAM. _Must_ be 0 here.
1306
1307- CFG_MBIO_BASE:
1308 Physical start address of Motherboard I/O (if using a
1309 Cogent motherboard)
1310
1311- CFG_FLASH_BASE:
1312 Physical start address of Flash memory.
1313
1314- CFG_MONITOR_BASE:
1315 Physical start address of boot monitor code (set by
1316 make config files to be same as the text base address
1317 (TEXT_BASE) used when linking) - same as
1318 CFG_FLASH_BASE when booting from flash.
1319
1320- CFG_MONITOR_LEN:
1321 Size of memory reserved for monitor code
1322
1323- CFG_MALLOC_LEN:
1324 Size of DRAM reserved for malloc() use.
1325
1326- CFG_BOOTMAPSZ:
1327 Maximum size of memory mapped by the startup code of
1328 the Linux kernel; all data that must be processed by
1329 the Linux kernel (bd_info, boot arguments, eventually
1330 initrd image) must be put below this limit.
1331
1332- CFG_MAX_FLASH_BANKS:
1333 Max number of Flash memory banks
1334
1335- CFG_MAX_FLASH_SECT:
1336 Max number of sectors on a Flash chip
1337
1338- CFG_FLASH_ERASE_TOUT:
1339 Timeout for Flash erase operations (in ms)
1340
1341- CFG_FLASH_WRITE_TOUT:
1342 Timeout for Flash write operations (in ms)
1343
1344- CFG_DIRECT_FLASH_TFTP:
1345
1346 Enable TFTP transfers directly to flash memory;
1347 without this option such a download has to be
1348 performed in two steps: (1) download to RAM, and (2)
1349 copy from RAM to flash.
1350
1351 The two-step approach is usually more reliable, since
1352 you can check if the download worked before you erase
1353 the flash, but in some situations (when sytem RAM is
1354 too limited to allow for a tempory copy of the
1355 downloaded image) this option may be very useful.
1356
1357- CFG_FLASH_CFI:
1358 Define if the flash driver uses extra elements in the
1359 common flash structure for storing flash geometry
1360
1361The following definitions that deal with the placement and management
1362of environment data (variable area); in general, we support the
1363following configurations:
1364
1365- CFG_ENV_IS_IN_FLASH:
1366
1367 Define this if the environment is in flash memory.
1368
1369 a) The environment occupies one whole flash sector, which is
1370 "embedded" in the text segment with the U-Boot code. This
1371 happens usually with "bottom boot sector" or "top boot
1372 sector" type flash chips, which have several smaller
1373 sectors at the start or the end. For instance, such a
1374 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1375 such a case you would place the environment in one of the
1376 4 kB sectors - with U-Boot code before and after it. With
1377 "top boot sector" type flash chips, you would put the
1378 environment in one of the last sectors, leaving a gap
1379 between U-Boot and the environment.
1380
1381 - CFG_ENV_OFFSET:
1382
1383 Offset of environment data (variable area) to the
1384 beginning of flash memory; for instance, with bottom boot
1385 type flash chips the second sector can be used: the offset
1386 for this sector is given here.
1387
1388 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1389
1390 - CFG_ENV_ADDR:
1391
1392 This is just another way to specify the start address of
1393 the flash sector containing the environment (instead of
1394 CFG_ENV_OFFSET).
1395
1396 - CFG_ENV_SECT_SIZE:
1397
1398 Size of the sector containing the environment.
1399
1400
1401 b) Sometimes flash chips have few, equal sized, BIG sectors.
1402 In such a case you don't want to spend a whole sector for
1403 the environment.
1404
1405 - CFG_ENV_SIZE:
1406
1407 If you use this in combination with CFG_ENV_IS_IN_FLASH
1408 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1409 of this flash sector for the environment. This saves
1410 memory for the RAM copy of the environment.
1411
1412 It may also save flash memory if you decide to use this
1413 when your environment is "embedded" within U-Boot code,
1414 since then the remainder of the flash sector could be used
1415 for U-Boot code. It should be pointed out that this is
1416 STRONGLY DISCOURAGED from a robustness point of view:
1417 updating the environment in flash makes it always
1418 necessary to erase the WHOLE sector. If something goes
1419 wrong before the contents has been restored from a copy in
1420 RAM, your target system will be dead.
1421
1422 - CFG_ENV_ADDR_REDUND
1423 CFG_ENV_SIZE_REDUND
1424
1425 These settings describe a second storage area used to hold
1426 a redundand copy of the environment data, so that there is
1427 a valid backup copy in case there is a power failur during
1428 a "saveenv" operation.
1429
1430BE CAREFUL! Any changes to the flash layout, and some changes to the
1431source code will make it necessary to adapt <board>/u-boot.lds*
1432accordingly!
1433
1434
1435- CFG_ENV_IS_IN_NVRAM:
1436
1437 Define this if you have some non-volatile memory device
1438 (NVRAM, battery buffered SRAM) which you want to use for the
1439 environment.
1440
1441 - CFG_ENV_ADDR:
1442 - CFG_ENV_SIZE:
1443
1444 These two #defines are used to determin the memory area you
1445 want to use for environment. It is assumed that this memory
1446 can just be read and written to, without any special
1447 provision.
1448
1449BE CAREFUL! The first access to the environment happens quite early
1450in U-Boot initalization (when we try to get the setting of for the
1451console baudrate). You *MUST* have mappend your NVRAM area then, or
1452U-Boot will hang.
1453
1454Please note that even with NVRAM we still use a copy of the
1455environment in RAM: we could work on NVRAM directly, but we want to
1456keep settings there always unmodified except somebody uses "saveenv"
1457to save the current settings.
1458
1459
1460- CFG_ENV_IS_IN_EEPROM:
1461
1462 Use this if you have an EEPROM or similar serial access
1463 device and a driver for it.
1464
1465 - CFG_ENV_OFFSET:
1466 - CFG_ENV_SIZE:
1467
1468 These two #defines specify the offset and size of the
1469 environment area within the total memory of your EEPROM.
1470
1471 - CFG_I2C_EEPROM_ADDR:
1472 If defined, specified the chip address of the EEPROM device.
1473 The default address is zero.
1474
1475 - CFG_EEPROM_PAGE_WRITE_BITS:
1476 If defined, the number of bits used to address bytes in a
1477 single page in the EEPROM device. A 64 byte page, for example
1478 would require six bits.
1479
1480 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1481 If defined, the number of milliseconds to delay between
1482 page writes. The default is zero milliseconds.
1483
1484 - CFG_I2C_EEPROM_ADDR_LEN:
1485 The length in bytes of the EEPROM memory array address. Note
1486 that this is NOT the chip address length!
1487
1488 - CFG_EEPROM_SIZE:
1489 The size in bytes of the EEPROM device.
1490
1491 - CFG_I2C_EEPROM_ADDR:
1492 If defined, specified the chip address of the EEPROM device.
1493 The default address is zero.
1494
1495 - CFG_EEPROM_PAGE_WRITE_BITS:
1496 If defined, the number of bits used to address bytes in a
1497 single page in the EEPROM device. A 64 byte page, for example
1498 would require six bits.
1499
1500 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1501 If defined, the number of milliseconds to delay between
1502 page writes. The default is zero milliseconds.
1503
1504 - CFG_I2C_EEPROM_ADDR_LEN:
1505 The length in bytes of the EEPROM memory array address. Note
1506 that this is NOT the chip address length!
1507
1508 - CFG_EEPROM_SIZE:
1509 The size in bytes of the EEPROM device.
1510
1511- CFG_SPI_INIT_OFFSET
1512
1513 Defines offset to the initial SPI buffer area in DPRAM. The
1514 area is used at an early stage (ROM part) if the environment
1515 is configured to reside in the SPI EEPROM: We need a 520 byte
1516 scratch DPRAM area. It is used between the two initialization
1517 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1518 to be a good choice since it makes it far enough from the
1519 start of the data area as well as from the stack pointer.
1520
1521Please note that the environment is read-only as long as the monitor
1522has been relocated to RAM and a RAM copy of the environment has been
1523created; also, when using EEPROM you will have to use getenv_r()
1524until then to read environment variables.
1525
1526The environment is now protected by a CRC32 checksum. Before the
1527monitor is relocated into RAM, as a result of a bad CRC you will be
1528working with the compiled-in default environment - *silently*!!!
1529[This is necessary, because the first environment variable we need is
1530the "baudrate" setting for the console - if we have a bad CRC, we
1531don't have any device yet where we could complain.]
1532
1533Note: once the monitor has been relocated, then it will complain if
1534the default environment is used; a new CRC is computed as soon as you
1535use the "setenv" command to modify / delete / add any environment
1536variable [even when you try to delete a non-existing variable!].
1537
1538Note2: you must edit your u-boot.lds file to reflect this
1539configuration.
1540
1541
wdenkc6097192002-11-03 00:24:07 +00001542Low Level (hardware related) configuration options:
1543
1544- CFG_CACHELINE_SIZE:
1545 Cache Line Size of the CPU.
1546
1547- CFG_DEFAULT_IMMR:
1548 Default address of the IMMR after system reset.
1549 Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1550 to be able to adjust the position of the IMMR
1551 register after a reset.
1552
wdenk7f6c2cb2002-11-10 22:06:23 +00001553- Floppy Disk Support:
1554 CFG_FDC_DRIVE_NUMBER
1555
1556 the default drive number (default value 0)
1557
1558 CFG_ISA_IO_STRIDE
1559
1560 defines the spacing between fdc chipset registers
1561 (default value 1)
1562
1563 CFG_ISA_IO_OFFSET
1564
1565 defines the offset of register from address. It
1566 depends on which part of the data bus is connected to
1567 the fdc chipset. (default value 0)
1568
1569 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1570 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1571 default value.
1572
1573 if CFG_FDC_HW_INIT is defined, then the function
1574 fdc_hw_init() is called at the beginning of the FDC
1575 setup. fdc_hw_init() must be provided by the board
1576 source code. It is used to make hardware dependant
1577 initializations.
1578
wdenkc6097192002-11-03 00:24:07 +00001579- CFG_IMMR: Physical address of the Internal Memory Mapped
1580 Register; DO NOT CHANGE! (11-4)
1581 [MPC8xx systems only]
1582
1583- CFG_INIT_RAM_ADDR:
1584
1585 Start address of memory area tha can be used for
1586 initial data and stack; please note that this must be
1587 writable memory that is working WITHOUT special
1588 initialization, i. e. you CANNOT use normal RAM which
1589 will become available only after programming the
1590 memory controller and running certain initialization
1591 sequences.
1592
1593 U-Boot uses the following memory types:
1594 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1595 - MPC824X: data cache
1596 - PPC4xx: data cache
1597
1598- CFG_INIT_DATA_OFFSET:
1599
1600 Offset of the initial data structure in the memory
1601 area defined by CFG_INIT_RAM_ADDR. Usually
1602 CFG_INIT_DATA_OFFSET is chosen such that the initial
1603 data is located at the end of the available space
1604 (sometimes written as (CFG_INIT_RAM_END -
1605 CFG_INIT_DATA_SIZE), and the initial stack is just
1606 below that area (growing from (CFG_INIT_RAM_ADDR +
1607 CFG_INIT_DATA_OFFSET) downward.
1608
1609 Note:
1610 On the MPC824X (or other systems that use the data
1611 cache for initial memory) the address chosen for
1612 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1613 point to an otherwise UNUSED address space between
1614 the top of RAM and the start of the PCI space.
1615
1616- CFG_SIUMCR: SIU Module Configuration (11-6)
1617
1618- CFG_SYPCR: System Protection Control (11-9)
1619
1620- CFG_TBSCR: Time Base Status and Control (11-26)
1621
1622- CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1623
1624- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1625
1626- CFG_SCCR: System Clock and reset Control Register (15-27)
1627
1628- CFG_OR_TIMING_SDRAM:
1629 SDRAM timing
1630
1631- CFG_MAMR_PTA:
1632 periodic timer for refresh
1633
1634- CFG_DER: Debug Event Register (37-47)
1635
1636- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1637 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1638 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1639 CFG_BR1_PRELIM:
1640 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1641
1642- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1643 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1644 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1645 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1646
1647- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1648 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1649 Machine Mode Register and Memory Periodic Timer
1650 Prescaler definitions (SDRAM timing)
1651
1652- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1653 enable I2C microcode relocation patch (MPC8xx);
1654 define relocation offset in DPRAM [DSP2]
1655
1656- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1657 enable SPI microcode relocation patch (MPC8xx);
1658 define relocation offset in DPRAM [SCC4]
1659
1660- CFG_USE_OSCCLK:
1661 Use OSCM clock mode on MBX8xx board. Be careful,
1662 wrong setting might damage your board. Read
1663 doc/README.MBX before setting this variable!
1664
wdenkea909b72002-11-21 23:11:29 +00001665- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1666 Offset of the bootmode word in DPRAM used by post
1667 (Power On Self Tests). This definition overrides
1668 #define'd default value in commproc.h resp.
1669 cpm_8260.h.
1670
wdenkc6097192002-11-03 00:24:07 +00001671Building the Software:
1672======================
1673
1674Building U-Boot has been tested in native PPC environments (on a
1675PowerBook G3 running LinuxPPC 2000) and in cross environments
1676(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1677NetBSD 1.5 on x86).
1678
1679If you are not using a native PPC environment, it is assumed that you
1680have the GNU cross compiling tools available in your path and named
1681with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1682you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1683the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1684change it to:
1685
1686 CROSS_COMPILE = ppc_4xx-
1687
1688
1689U-Boot is intended to be simple to build. After installing the
1690sources you must configure U-Boot for one specific board type. This
1691is done by typing:
1692
1693 make NAME_config
1694
1695where "NAME_config" is the name of one of the existing
1696configurations; the following names are supported:
1697
1698 ADCIOP_config GTH_config TQM850L_config
1699 ADS860_config IP860_config TQM855L_config
1700 AR405_config IVML24_config TQM860L_config
1701 CANBT_config IVMS8_config WALNUT405_config
1702 CPCI405_config LANTEC_config cogent_common_config
1703 CPCIISER4_config MBX_config cogent_mpc8260_config
1704 CU824_config MBX860T_config cogent_mpc8xx_config
1705 ESTEEM192E_config RPXlite_config hermes_config
1706 ETX094_config RPXsuper_config hymod_config
1707 FADS823_config SM850_config lwmon_config
1708 FADS850SAR_config SPD823TS_config pcu_e_config
1709 FADS860T_config SXNI855T_config rsdproto_config
1710 FPS850L_config Sandpoint8240_config sbc8260_config
1711 GENIETV_config TQM823L_config PIP405_config
wdenk384ae022002-11-05 00:17:55 +00001712 GEN860T_config EBONY_config FPS860L_config
wdenkc6097192002-11-03 00:24:07 +00001713
1714Note: for some board special configuration names may exist; check if
1715 additional information is available from the board vendor; for
1716 instance, the TQM8xxL systems run normally at 50 MHz and use a
1717 SCC for 10baseT ethernet; there are also systems with 80 MHz
1718 CPU clock, and an optional Fast Ethernet module is available
1719 for CPU's with FEC. You can select such additional "features"
1720 when chosing the configuration, i. e.
1721
1722 make TQM860L_config
1723 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1724
1725 make TQM860L_FEC_config
1726 - will configure for a TQM860L at 50MHz with FEC for ethernet
1727
1728 make TQM860L_80MHz_config
1729 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1730 interface
1731
1732 make TQM860L_FEC_80MHz_config
1733 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1734
1735 make TQM823L_LCD_config
1736 - will configure for a TQM823L with U-Boot console on LCD
1737
1738 make TQM823L_LCD_80MHz_config
1739 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1740
1741 etc.
1742
1743
1744
wdenk24ee89b2002-11-03 17:56:27 +00001745Finally, type "make all", and you should get some working U-Boot
wdenkc6097192002-11-03 00:24:07 +00001746images ready for downlod to / installation on your system:
1747
1748- "u-boot.bin" is a raw binary image
1749- "u-boot" is an image in ELF binary format
1750- "u-boot.srec" is in Motorola S-Record format
1751
1752
1753Please be aware that the Makefiles assume you are using GNU make, so
1754for instance on NetBSD you might need to use "gmake" instead of
1755native "make".
1756
1757
1758If the system board that you have is not listed, then you will need
1759to port U-Boot to your hardware platform. To do this, follow these
1760steps:
1761
17621. Add a new configuration option for your board to the toplevel
1763 "Makefile", using the existing entries as examples.
17642. Create a new directory to hold your board specific code. Add any
1765 files you need.
17663. If you're porting U-Boot to a new CPU, then also create a new
1767 directory to hold your CPU specific code. Add any files you need.
17684. Run "make config_name" with your new name.
17695. Type "make", and you should get a working "u-boot.srec" file
1770 to be installed on your target system.
1771 [Of course, this last step is much harder than it sounds.]
1772
1773
1774Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1775==============================================================
1776
1777If you have modified U-Boot sources (for instance added a new board
1778or support for new devices, a new CPU, etc.) you are expected to
1779provide feedback to the other developers. The feedback normally takes
1780the form of a "patch", i. e. a context diff against a certain (latest
1781official or latest in CVS) version of U-Boot sources.
1782
1783But before you submit such a patch, please verify that your modifi-
1784cation did not break existing code. At least make sure that *ALL* of
1785the supported boards compile WITHOUT ANY compiler warnings. To do so,
1786just run the "MAKEALL" script, which will configure and build U-Boot
1787for ALL supported system. Be warned, this will take a while. You can
1788select which (cross) compiler to use py passing a `CROSS_COMPILE'
1789environment variable to the script, i. e. to use the cross tools from
1790MontaVista's Hard Hat Linux you can type
1791
1792 CROSS_COMPILE=ppc_8xx- MAKEALL
1793
1794or to build on a native PowerPC system you can type
1795
1796 CROSS_COMPILE=' ' MAKEALL
1797
1798See also "U-Boot Porting Guide" below.
1799
1800
1801
1802Monitor Commands - Overview:
1803============================
1804
1805go - start application at address 'addr'
1806run - run commands in an environment variable
1807bootm - boot application image from memory
1808bootp - boot image via network using BootP/TFTP protocol
1809tftpboot- boot image via network using TFTP protocol
1810 and env variables "ipaddr" and "serverip"
1811 (and eventually "gatewayip")
1812rarpboot- boot image via network using RARP/TFTP protocol
1813diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1814loads - load S-Record file over serial line
1815loadb - load binary file over serial line (kermit mode)
1816md - memory display
1817mm - memory modify (auto-incrementing)
1818nm - memory modify (constant address)
1819mw - memory write (fill)
1820cp - memory copy
1821cmp - memory compare
1822crc32 - checksum calculation
1823imd - i2c memory display
1824imm - i2c memory modify (auto-incrementing)
1825inm - i2c memory modify (constant address)
1826imw - i2c memory write (fill)
1827icrc32 - i2c checksum calculation
1828iprobe - probe to discover valid I2C chip addresses
1829iloop - infinite loop on address range
1830isdram - print SDRAM configuration information
1831sspi - SPI utility commands
1832base - print or set address offset
1833printenv- print environment variables
1834setenv - set environment variables
1835saveenv - save environment variables to persistent storage
1836protect - enable or disable FLASH write protection
1837erase - erase FLASH memory
1838flinfo - print FLASH memory information
1839bdinfo - print Board Info structure
1840iminfo - print header information for application image
1841coninfo - print console devices and informations
1842ide - IDE sub-system
1843loop - infinite loop on address range
1844mtest - simple RAM test
1845icache - enable or disable instruction cache
1846dcache - enable or disable data cache
1847reset - Perform RESET of the CPU
1848echo - echo args to console
1849version - print monitor version
1850help - print online help
1851? - alias for 'help'
1852
1853
1854Monitor Commands - Detailed Description:
1855========================================
1856
1857TODO.
1858
1859For now: just type "help <command>".
1860
1861
1862Environment Variables:
1863======================
1864
1865U-Boot supports user configuration using Environment Variables which
1866can be made persistent by saving to Flash memory.
1867
1868Environment Variables are set using "setenv", printed using
1869"printenv", and saved to Flash using "saveenv". Using "setenv"
1870without a value can be used to delete a variable from the
1871environment. As long as you don't save the environment you are
1872working with an in-memory copy. In case the Flash area containing the
1873environment is erased by accident, a default environment is provided.
1874
1875Some configuration options can be set using Environment Variables:
1876
1877 baudrate - see CONFIG_BAUDRATE
1878
1879 bootdelay - see CONFIG_BOOTDELAY
1880
1881 bootcmd - see CONFIG_BOOTCOMMAND
1882
1883 bootargs - Boot arguments when booting an RTOS image
1884
1885 bootfile - Name of the image to load with TFTP
1886
1887 autoload - if set to "no" (any string beginning with 'n'),
1888 "bootp" will just load perform a lookup of the
1889 configuration from the BOOTP server, but not try to
1890 load any image using TFTP
1891
1892 autostart - if set to "yes", an image loaded using the "bootp",
1893 "rarpboot", "tftpboot" or "diskboot" commands will
1894 be automatically started (by internally calling
1895 "bootm")
1896
1897 initrd_high - restrict positioning of initrd images:
1898 If this variable is not set, initrd images will be
1899 copied to the highest possible address in RAM; this
1900 is usually what you want since it allows for
1901 maximum initrd size. If for some reason you want to
1902 make sure that the initrd image is loaded below the
1903 CFG_BOOTMAPSZ limit, you can set this environment
1904 variable to a value of "no" or "off" or "0".
1905 Alternatively, you can set it to a maximum upper
1906 address to use (U-Boot will still check that it
1907 does not overwrite the U-Boot stack and data).
1908
1909 For instance, when you have a system with 16 MB
1910 RAM, and want to reseve 4 MB from use by Linux,
1911 you can do this by adding "mem=12M" to the value of
1912 the "bootargs" variable. However, now you must make
1913 sure, that the initrd image is placed in the first
1914 12 MB as well - this can be done with
1915
1916 setenv initrd_high 00c00000
1917
1918 ipaddr - IP address; needed for tftpboot command
1919
1920 loadaddr - Default load address for commands like "bootp",
1921 "rarpboot", "tftpboot" or "diskboot"
1922
1923 loads_echo - see CONFIG_LOADS_ECHO
1924
1925 serverip - TFTP server IP address; needed for tftpboot command
1926
1927 bootretry - see CONFIG_BOOT_RETRY_TIME
1928
1929 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
1930
1931 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
1932
1933
1934The following environment variables may be used and automatically
1935updated by the network boot commands ("bootp" and "rarpboot"),
1936depending the information provided by your boot server:
1937
1938 bootfile - see above
1939 dnsip - IP address of your Domain Name Server
1940 gatewayip - IP address of the Gateway (Router) to use
1941 hostname - Target hostname
1942 ipaddr - see above
1943 netmask - Subnet Mask
1944 rootpath - Pathname of the root filesystem on the NFS server
1945 serverip - see above
1946
1947
1948There are two special Environment Variables:
1949
1950 serial# - contains hardware identification information such
1951 as type string and/or serial number
1952 ethaddr - Ethernet address
1953
1954These variables can be set only once (usually during manufacturing of
1955the board). U-Boot refuses to delete or overwrite these variables
1956once they have been set once.
1957
1958
1959Please note that changes to some configuration parameters may take
1960only effect after the next boot (yes, that's just like Windoze :-).
1961
1962
1963Note for Redundant Ethernet Interfaces:
1964=======================================
1965
1966Some boards come with redundand ethernet interfaces; U-Boot supports
1967such configurations and is capable of automatic selection of a
1968"working" interface when needed. MAC assignemnt works as follows:
1969
1970Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
1971MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1972"eth1addr" (=>eth1), "eth2addr", ...
1973
1974If the network interface stores some valid MAC address (for instance
1975in SROM), this is used as default address if there is NO correspon-
1976ding setting in the environment; if the corresponding environment
1977variable is set, this overrides the settings in the card; that means:
1978
1979o If the SROM has a valid MAC address, and there is no address in the
1980 environment, the SROM's address is used.
1981
1982o If there is no valid address in the SROM, and a definition in the
1983 environment exists, then the value from the environment variable is
1984 used.
1985
1986o If both the SROM and the environment contain a MAC address, and
1987 both addresses are the same, this MAC address is used.
1988
1989o If both the SROM and the environment contain a MAC address, and the
1990 addresses differ, the value from the environment is used and a
1991 warning is printed.
1992
1993o If neither SROM nor the environment contain a MAC address, an error
1994 is raised.
1995
1996
1997
1998Image Formats:
1999==============
2000
2001The "boot" commands of this monitor operate on "image" files which
2002can be basicly anything, preceeded by a special header; see the
2003definitions in include/image.h for details; basicly, the header
2004defines the following image properties:
2005
2006* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2007 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2008 LynxOS, pSOS, QNX;
2009 Currently supported: Linux, NetBSD, VxWorks, QNX).
2010* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2011 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2012 Currently supported: PowerPC).
2013* Compression Type (Provisions for uncompressed, gzip, bzip2;
2014 Currently supported: uncompressed, gzip).
2015* Load Address
2016* Entry Point
2017* Image Name
2018* Image Timestamp
2019
2020The header is marked by a special Magic Number, and both the header
2021and the data portions of the image are secured against corruption by
2022CRC32 checksums.
2023
2024
2025Linux Support:
2026==============
2027
2028Although U-Boot should support any OS or standalone application
2029easily, Linux has always been in the focus during the design of
2030U-Boot.
2031
2032U-Boot includes many features that so far have been part of some
2033special "boot loader" code within the Linux kernel. Also, any
2034"initrd" images to be used are no longer part of one big Linux image;
2035instead, kernel and "initrd" are separate images. This implementation
2036serves serveral purposes:
2037
2038- the same features can be used for other OS or standalone
2039 applications (for instance: using compressed images to reduce the
2040 Flash memory footprint)
2041
2042- it becomes much easier to port new Linux kernel versions because
2043 lots of low-level, hardware dependend stuff are done by U-Boot
2044
2045- the same Linux kernel image can now be used with different "initrd"
2046 images; of course this also means that different kernel images can
2047 be run with the same "initrd". This makes testing easier (you don't
2048 have to build a new "zImage.initrd" Linux image when you just
2049 change a file in your "initrd"). Also, a field-upgrade of the
2050 software is easier now.
2051
2052
2053Linux HOWTO:
2054============
2055
2056Porting Linux to U-Boot based systems:
2057---------------------------------------
2058
2059U-Boot cannot save you from doing all the necessary modifications to
2060configure the Linux device drivers for use with your target hardware
2061(no, we don't intend to provide a full virtual machine interface to
2062Linux :-).
2063
2064But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2065
2066Just make sure your machine specific header file (for instance
2067include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2068Information structure as we define in include/u-boot.h, and make
2069sure that your definition of IMAP_ADDR uses the same value as your
2070U-Boot configuration in CFG_IMMR.
2071
2072
2073Configuring the Linux kernel:
2074-----------------------------
2075
2076No specific requirements for U-Boot. Make sure you have some root
2077device (initial ramdisk, NFS) for your target system.
2078
2079
2080Building a Linux Image:
2081-----------------------
2082
wdenk24ee89b2002-11-03 17:56:27 +00002083With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2084not used. If you use recent kernel source, a new build target
2085"uImage" will exist which automatically builds an image usable by
2086U-Boot. Most older kernels also have support for a "pImage" target,
2087which was introduced for our predecessor project PPCBoot and uses a
2088100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002089
2090Example:
2091
2092 make TQM850L_config
2093 make oldconfig
2094 make dep
wdenk24ee89b2002-11-03 17:56:27 +00002095 make uImage
wdenkc6097192002-11-03 00:24:07 +00002096
wdenk24ee89b2002-11-03 17:56:27 +00002097The "uImage" build target uses a special tool (in 'tools/mkimage') to
2098encapsulate a compressed Linux kernel image with header information,
2099CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002100
wdenk24ee89b2002-11-03 17:56:27 +00002101* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002102
wdenk24ee89b2002-11-03 17:56:27 +00002103* convert the kernel into a raw binary image:
2104
2105 ${CROSS_COMPILE}-objcopy -O binary \
2106 -R .note -R .comment \
2107 -S vmlinux linux.bin
2108
2109* compress the binary image:
2110
2111 gzip -9 linux.bin
2112
2113* package compressed binary image for U-Boot:
2114
2115 mkimage -A ppc -O linux -T kernel -C gzip \
2116 -a 0 -e 0 -n "Linux Kernel Image" \
2117 -d linux.bin.gz uImage
2118
2119
2120The "mkimage" tool can also be used to create ramdisk images for use
2121with U-Boot, either separated from the Linux kernel image, or
2122combined into one file. "mkimage" encapsulates the images with a 64
2123byte header containing information about target architecture,
2124operating system, image type, compression method, entry points, time
2125stamp, CRC32 checksums, etc.
2126
2127"mkimage" can be called in two ways: to verify existing images and
2128print the header information, or to build new images.
2129
2130In the first form (with "-l" option) mkimage lists the information
2131contained in the header of an existing U-Boot image; this includes
wdenkc6097192002-11-03 00:24:07 +00002132checksum verification:
2133
2134 tools/mkimage -l image
2135 -l ==> list image header information
2136
2137The second form (with "-d" option) is used to build a U-Boot image
2138from a "data file" which is used as image payload:
2139
2140 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2141 -n name -d data_file image
2142 -A ==> set architecture to 'arch'
2143 -O ==> set operating system to 'os'
2144 -T ==> set image type to 'type'
2145 -C ==> set compression type 'comp'
2146 -a ==> set load address to 'addr' (hex)
2147 -e ==> set entry point to 'ep' (hex)
2148 -n ==> set image name to 'name'
2149 -d ==> use image data from 'datafile'
2150
2151Right now, all Linux kernels use the same load address (0x00000000),
2152but the entry point address depends on the kernel version:
2153
2154- 2.2.x kernels have the entry point at 0x0000000C,
wdenk24ee89b2002-11-03 17:56:27 +00002155- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002156
2157So a typical call to build a U-Boot image would read:
2158
wdenk24ee89b2002-11-03 17:56:27 +00002159 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2160 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2161 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2162 > examples/uImage.TQM850L
2163 Image Name: 2.4.4 kernel for TQM850L
wdenkc6097192002-11-03 00:24:07 +00002164 Created: Wed Jul 19 02:34:59 2000
2165 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2166 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2167 Load Address: 0x00000000
wdenk24ee89b2002-11-03 17:56:27 +00002168 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002169
2170To verify the contents of the image (or check for corruption):
2171
wdenk24ee89b2002-11-03 17:56:27 +00002172 -> tools/mkimage -l examples/uImage.TQM850L
2173 Image Name: 2.4.4 kernel for TQM850L
wdenkc6097192002-11-03 00:24:07 +00002174 Created: Wed Jul 19 02:34:59 2000
2175 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2176 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2177 Load Address: 0x00000000
wdenk24ee89b2002-11-03 17:56:27 +00002178 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002179
2180NOTE: for embedded systems where boot time is critical you can trade
2181speed for memory and install an UNCOMPRESSED image instead: this
2182needs more space in Flash, but boots much faster since it does not
2183need to be uncompressed:
2184
wdenk24ee89b2002-11-03 17:56:27 +00002185 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2186 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2187 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2188 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2189 > examples/uImage.TQM850L-uncompressed
2190 Image Name: 2.4.4 kernel for TQM850L
wdenkc6097192002-11-03 00:24:07 +00002191 Created: Wed Jul 19 02:34:59 2000
2192 Image Type: PowerPC Linux Kernel Image (uncompressed)
2193 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2194 Load Address: 0x00000000
wdenk24ee89b2002-11-03 17:56:27 +00002195 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002196
2197
2198Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2199when your kernel is intended to use an initial ramdisk:
2200
2201 -> tools/mkimage -n 'Simple Ramdisk Image' \
2202 > -A ppc -O linux -T ramdisk -C gzip \
2203 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2204 Image Name: Simple Ramdisk Image
2205 Created: Wed Jan 12 14:01:50 2000
2206 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2207 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2208 Load Address: 0x00000000
2209 Entry Point: 0x00000000
2210
2211
2212Installing a Linux Image:
2213-------------------------
2214
2215To downloading a U-Boot image over the serial (console) interface,
2216you must convert the image to S-Record format:
2217
2218 objcopy -I binary -O srec examples/image examples/image.srec
2219
2220The 'objcopy' does not understand the information in the U-Boot
2221image header, so the resulting S-Record file will be relative to
2222address 0x00000000. To load it to a given address, you need to
2223specify the target address as 'offset' parameter with the 'loads'
2224command.
2225
2226Example: install the image to address 0x40100000 (which on the
2227TQM8xxL is in the first Flash bank):
2228
2229 => erase 40100000 401FFFFF
2230
2231 .......... done
2232 Erased 8 sectors
2233
2234 => loads 40100000
2235 ## Ready for S-Record download ...
2236 ~>examples/image.srec
2237 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2238 ...
2239 15989 15990 15991 15992
2240 [file transfer complete]
2241 [connected]
2242 ## Start Addr = 0x00000000
2243
2244
2245You can check the success of the download using the 'iminfo' command;
2246this includes a checksum verification so you can be sure no data
2247corruption happened:
2248
2249 => imi 40100000
2250
2251 ## Checking Image at 40100000 ...
2252 Image Name: 2.2.13 for initrd on TQM850L
2253 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2254 Data Size: 335725 Bytes = 327 kB = 0 MB
2255 Load Address: 00000000
2256 Entry Point: 0000000c
2257 Verifying Checksum ... OK
2258
2259
2260
2261Boot Linux:
2262-----------
2263
2264The "bootm" command is used to boot an application that is stored in
2265memory (RAM or Flash). In case of a Linux kernel image, the contents
2266of the "bootargs" environment variable is passed to the kernel as
2267parameters. You can check and modify this variable using the
2268"printenv" and "setenv" commands:
2269
2270
2271 => printenv bootargs
2272 bootargs=root=/dev/ram
2273
2274 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2275
2276 => printenv bootargs
2277 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2278
2279 => bootm 40020000
2280 ## Booting Linux kernel at 40020000 ...
2281 Image Name: 2.2.13 for NFS on TQM850L
2282 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2283 Data Size: 381681 Bytes = 372 kB = 0 MB
2284 Load Address: 00000000
2285 Entry Point: 0000000c
2286 Verifying Checksum ... OK
2287 Uncompressing Kernel Image ... OK
2288 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
2289 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2290 time_init: decrementer frequency = 187500000/60
2291 Calibrating delay loop... 49.77 BogoMIPS
2292 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2293 ...
2294
2295If you want to boot a Linux kernel with initial ram disk, you pass
2296the memory addreses of both the kernel and the initrd image (PPBCOOT
2297format!) to the "bootm" command:
2298
2299 => imi 40100000 40200000
2300
2301 ## Checking Image at 40100000 ...
2302 Image Name: 2.2.13 for initrd on TQM850L
2303 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2304 Data Size: 335725 Bytes = 327 kB = 0 MB
2305 Load Address: 00000000
2306 Entry Point: 0000000c
2307 Verifying Checksum ... OK
2308
2309 ## Checking Image at 40200000 ...
2310 Image Name: Simple Ramdisk Image
2311 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2312 Data Size: 566530 Bytes = 553 kB = 0 MB
2313 Load Address: 00000000
2314 Entry Point: 00000000
2315 Verifying Checksum ... OK
2316
2317 => bootm 40100000 40200000
2318 ## Booting Linux kernel at 40100000 ...
2319 Image Name: 2.2.13 for initrd on TQM850L
2320 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2321 Data Size: 335725 Bytes = 327 kB = 0 MB
2322 Load Address: 00000000
2323 Entry Point: 0000000c
2324 Verifying Checksum ... OK
2325 Uncompressing Kernel Image ... OK
2326 ## Loading RAMDisk Image at 40200000 ...
2327 Image Name: Simple Ramdisk Image
2328 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2329 Data Size: 566530 Bytes = 553 kB = 0 MB
2330 Load Address: 00000000
2331 Entry Point: 00000000
2332 Verifying Checksum ... OK
2333 Loading Ramdisk ... OK
2334 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
2335 Boot arguments: root=/dev/ram
2336 time_init: decrementer frequency = 187500000/60
2337 Calibrating delay loop... 49.77 BogoMIPS
2338 ...
2339 RAMDISK: Compressed image found at block 0
2340 VFS: Mounted root (ext2 filesystem).
2341
2342 bash#
2343
2344
2345Standalone HOWTO:
2346=================
2347
2348One of the features of U-Boot is that you can dynamically load and
2349run "standalone" applications, which can use some resources of
2350U-Boot like console I/O functions or interrupt services.
2351
2352Two simple examples are included with the sources:
2353
2354"Hello World" Demo:
2355-------------------
2356
2357'examples/hello_world.c' contains a small "Hello World" Demo
2358application; it is automatically compiled when you build U-Boot.
2359It's configured to run at address 0x00040004, so you can play with it
2360like that:
2361
2362 => loads
2363 ## Ready for S-Record download ...
2364 ~>examples/hello_world.srec
2365 1 2 3 4 5 6 7 8 9 10 11 ...
2366 [file transfer complete]
2367 [connected]
2368 ## Start Addr = 0x00040004
2369
2370 => go 40004 Hello World! This is a test.
2371 ## Starting application at 0x00040004 ...
2372 Hello World
2373 argc = 7
2374 argv[0] = "40004"
2375 argv[1] = "Hello"
2376 argv[2] = "World!"
2377 argv[3] = "This"
2378 argv[4] = "is"
2379 argv[5] = "a"
2380 argv[6] = "test."
2381 argv[7] = "<NULL>"
2382 Hit any key to exit ...
2383
2384 ## Application terminated, rc = 0x0
2385
2386Another example, which demonstrates how to register a CPM interrupt
2387handler with the U-Boot code, can be found in 'examples/timer.c'.
2388Here, a CPM timer is set up to generate an interrupt every second.
2389The interrupt service routine is trivial, just printing a '.'
2390character, but this is just a demo program. The application can be
2391controlled by the following keys:
2392
2393 ? - print current values og the CPM Timer registers
2394 b - enable interrupts and start timer
2395 e - stop timer and disable interrupts
2396 q - quit application
2397
2398 => loads
2399 ## Ready for S-Record download ...
2400 ~>examples/timer.srec
2401 1 2 3 4 5 6 7 8 9 10 11 ...
2402 [file transfer complete]
2403 [connected]
2404 ## Start Addr = 0x00040004
2405
2406 => go 40004
2407 ## Starting application at 0x00040004 ...
2408 TIMERS=0xfff00980
2409 Using timer 1
2410 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2411
2412Hit 'b':
2413 [q, b, e, ?] Set interval 1000000 us
2414 Enabling timer
2415Hit '?':
2416 [q, b, e, ?] ........
2417 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2418Hit '?':
2419 [q, b, e, ?] .
2420 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2421Hit '?':
2422 [q, b, e, ?] .
2423 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2424Hit '?':
2425 [q, b, e, ?] .
2426 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2427Hit 'e':
2428 [q, b, e, ?] ...Stopping timer
2429Hit 'q':
2430 [q, b, e, ?] ## Application terminated, rc = 0x0
2431
2432
2433NetBSD Notes:
2434=============
2435
2436Starting at version 0.9.2, U-Boot supports NetBSD both as host
2437(build U-Boot) and target system (boots NetBSD/mpc8xx).
2438
2439Building requires a cross environment; it is known to work on
2440NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2441need gmake since the Makefiles are not compatible with BSD make).
2442Note that the cross-powerpc package does not install include files;
2443attempting to build U-Boot will fail because <machine/ansi.h> is
2444missing. This file has to be installed and patched manually:
2445
2446 # cd /usr/pkg/cross/powerpc-netbsd/include
2447 # mkdir powerpc
2448 # ln -s powerpc machine
2449 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2450 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2451
2452Native builds *don't* work due to incompatibilities between native
2453and U-Boot include files.
2454
2455Booting assumes that (the first part of) the image booted is a
2456stage-2 loader which in turn loads and then invokes the kernel
2457proper. Loader sources will eventually appear in the NetBSD source
2458tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2459meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2460details.
2461
2462
2463Implementation Internals:
2464=========================
2465
2466The following is not intended to be a complete description of every
2467implementation detail. However, it should help to understand the
2468inner workings of U-Boot and make it easier to port it to custom
2469hardware.
2470
2471
2472Initial Stack, Global Data:
2473---------------------------
2474
2475The implementation of U-Boot is complicated by the fact that U-Boot
2476starts running out of ROM (flash memory), usually without access to
2477system RAM (because the memory controller is not initialized yet).
2478This means that we don't have writable Data or BSS segments, and BSS
2479is not initialized as zero. To be able to get a C environment working
2480at all, we have to allocate at least a minimal stack. Implementation
2481options for this are defined and restricted by the CPU used: Some CPU
2482models provide on-chip memory (like the IMMR area on MPC8xx and
2483MPC826x processors), on others (parts of) the data cache can be
2484locked as (mis-) used as memory, etc.
2485
2486It is essential to remember this, since it has some impact on the C
2487code for the initialization procedures:
2488
2489* Initialized global data (data segment) is read-only. Do not attempt
2490 to write it.
2491
2492* Do not use any unitialized global data (or implicitely initialized
2493 as zero data - BSS segment) at all - this is undefined, initiali-
2494 zation is performed later (when relocationg to RAM).
2495
2496* Stack space is very limited. Avoid big data buffers or things like
2497 that.
2498
2499Having only the stack as writable memory limits means we cannot use
2500normal global data to share information beween the code. But it
2501turned out that the implementation of U-Boot can be greatly
2502simplified by making a global data structure (gd_t) available to all
2503functions. We could pass a pointer to this data as argument to _all_
2504functions, but this would bloat the code. Instead we use a feature of
2505the GCC compiler (Global Register Variables) to share the data: we
2506place a pointer (gd) to the global data into a register which we
2507reserve for this purpose.
2508
2509When chosing a register for such a purpose we are restricted by the
2510relevant (E)ABI specifications for the current architecture, and by
2511GCC's implementation.
2512
2513For PowerPC, the following registers have specific use:
2514 R1: stack pointer
2515 R2: TOC pointer
2516 R3-R4: parameter passing and return values
2517 R5-R10: parameter passing
2518 R13: small data area pointer
2519 R30: GOT pointer
2520 R31: frame pointer
2521
2522 (U-Boot also uses R14 as internal GOT pointer.)
2523
2524 ==> U-Boot will use R29 to hold a pointer to the global data
2525
2526 Note: on PPC, we could use a static initializer (since the
2527 address of the global data structure is known at compile time),
2528 but it turned out that reserving a register results in somewhat
2529 smaller code - although the code savings are not that big (on
2530 average for all boards 752 bytes for the whole U-Boot image,
2531 624 text + 127 data).
2532
2533On ARM, the following registers are used:
2534
2535 R0: function argument word/integer result
2536 R1-R3: function argument word
2537 R9: GOT pointer
2538 R10: stack limit (used only if stack checking if enabled)
2539 R11: argument (frame) pointer
2540 R12: temporary workspace
2541 R13: stack pointer
2542 R14: link register
2543 R15: program counter
2544
2545 ==> U-Boot will use R8 to hold a pointer to the global data
2546
2547
2548
2549Memory Management:
2550------------------
2551
2552U-Boot runs in system state and uses physical addresses, i.e. the
2553MMU is not used either for address mapping nor for memory protection.
2554
2555The available memory is mapped to fixed addresses using the memory
2556controller. In this process, a contiguous block is formed for each
2557memory type (Flash, SDRAM, SRAM), even when it consists of several
2558physical memory banks.
2559
2560U-Boot is installed in the first 128 kB of the first Flash bank (on
2561TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2562booting and sizing and initializing DRAM, the code relocates itself
2563to the upper end of DRAM. Immediately below the U-Boot code some
2564memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2565configuration setting]. Below that, a structure with global Board
2566Info data is placed, followed by the stack (growing downward).
2567
2568Additionally, some exception handler code is copied to the low 8 kB
2569of DRAM (0x00000000 ... 0x00001FFF).
2570
2571So a typical memory configuration with 16 MB of DRAM could look like
2572this:
2573
2574 0x0000 0000 Exception Vector code
2575 :
2576 0x0000 1FFF
2577 0x0000 2000 Free for Application Use
2578 :
2579 :
2580
2581 :
2582 :
2583 0x00FB FF20 Monitor Stack (Growing downward)
2584 0x00FB FFAC Board Info Data and permanent copy of global data
2585 0x00FC 0000 Malloc Arena
2586 :
2587 0x00FD FFFF
2588 0x00FE 0000 RAM Copy of Monitor Code
2589 ... eventually: LCD or video framebuffer
2590 ... eventually: pRAM (Protected RAM - unchanged by reset)
2591 0x00FF FFFF [End of RAM]
2592
2593
2594System Initialization:
2595----------------------
2596
2597In the reset configuration, U-Boot starts at the reset entry point
2598(on most PowerPC systens at address 0x00000100). Because of the reset
2599configuration for CS0# this is a mirror of the onboard Flash memory.
2600To be able to re-map memory U-Boot then jumps to it's link address.
2601To be able to implement the initialization code in C, a (small!)
2602initial stack is set up in the internal Dual Ported RAM (in case CPUs
2603which provide such a feature like MPC8xx or MPC8260), or in a locked
2604part of the data cache. After that, U-Boot initializes the CPU core,
2605the caches and the SIU.
2606
2607Next, all (potentially) available memory banks are mapped using a
2608preliminary mapping. For example, we put them on 512 MB boundaries
2609(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2610on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2611programmed for SDRAM access. Using the temporary configuration, a
2612simple memory test is run that determines the size of the SDRAM
2613banks.
2614
2615When there is more than one SDRAM bank, and the banks are of
2616different size, the larger is mapped first. For equal size, the first
2617bank (CS2#) is mapped first. The first mapping is always for address
26180x00000000, with any additional banks following immediately to create
2619contiguous memory starting from 0.
2620
2621Then, the monitor installs itself at the upper end of the SDRAM area
2622and allocates memory for use by malloc() and for the global Board
2623Info data; also, the exception vector code is copied to the low RAM
2624pages, and the final stack is set up.
2625
2626Only after this relocation will you have a "normal" C environment;
2627until that you are restricted in several ways, mostly because you are
2628running from ROM, and because the code will have to be relocated to a
2629new address in RAM.
2630
2631
2632U-Boot Porting Guide:
2633----------------------
2634
2635[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2636list, Octover 2002]
2637
2638
2639int main (int argc, char *argv[])
2640{
2641 sighandler_t no_more_time;
2642
2643 signal (SIGALRM, no_more_time);
2644 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2645
2646 if (available_money > available_manpower) {
2647 pay consultant to port U-Boot;
2648 return 0;
2649 }
2650
2651 Download latest U-Boot source;
2652
2653 if (clueless) {
2654 email ("Hi, I am new to U-Boot, how do I get started?");
2655 }
2656
2657 while (learning) {
2658 Read the README file in the top level directory;
2659 Read http://www.denx.de/re/DPLG.html
2660 Read the source, Luke;
2661 }
2662
2663 if (available_money > toLocalCurrency ($2500)) {
2664 Buy a BDI2000;
2665 } else {
2666 Add a lot of aggravation and time;
2667 }
2668
2669 Create your own board support subdirectory;
2670
2671 while (!running) {
2672 do {
2673 Add / modify source code;
2674 } until (compiles);
2675 Debug;
2676 if (clueless)
2677 email ("Hi, I am having problems...");
2678 }
2679 Send patch file to Wolfgang;
2680
2681 return 0;
2682}
2683
2684void no_more_time (int sig)
2685{
2686 hire_a_guru();
2687}
2688
2689
2690
2691Coding Standards:
2692-----------------
2693
2694All contributions to U-Boot should conform to the Linux kernel
2695coding style; see the file "Documentation/CodingStyle" in your Linux
2696kernel source directory.
2697
2698Please note that U-Boot is implemented in C (and to some small parts
2699in Assembler); no C++ is used, so please do not use C++ style
2700comments (//) in your code.
2701
2702Submissions which do not conform to the standards may be returned
2703with a request to reformat the changes.
2704
2705
2706Submitting Patches:
2707-------------------
2708
2709Since the number of patches for U-Boot is growing, we need to
2710establish some rules. Submissions which do not conform to these rules
2711may be rejected, even when they contain important and valuable stuff.
2712
2713
2714When you send a patch, please include the following information with
2715it:
2716
2717* For bug fixes: a description of the bug and how your patch fixes
2718 this bug. Please try to include a way of demonstrating that the
2719 patch actually fixes something.
2720
2721* For new features: a description of the feature and your
2722 implementation.
2723
2724* A CHANGELOG entry as plaintext (separate from the patch)
2725
2726* For major contributions, your entry to the CREDITS file
2727
2728* When you add support for a new board, don't forget to add this
2729 board to the MAKEALL script, too.
2730
2731* If your patch adds new configuration options, don't forget to
2732 document these in the README file.
2733
2734* The patch itself. If you are accessing the CVS repository use "cvs
2735 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2736 version of diff does not support these options, then get the latest
2737 version of GNU diff.
2738
2739 We accept patches as plain text, MIME attachments or as uuencoded
2740 gzipped text.
2741
2742Notes:
2743
2744* Before sending the patch, run the MAKEALL script on your patched
2745 source tree and make sure that no errors or warnings are reported
2746 for any of the boards.
2747
2748* Keep your modifications to the necessary minimum: A patch
2749 containing several unrelated changes or arbitrary reformats will be
2750 returned with a request to re-formatting / split it.
2751
2752* If you modify existing code, make sure that your new code does not
2753 add to the memory footprint of the code ;-) Small is beautiful!
2754 When adding new features, these should compile conditionally only
2755 (using #ifdef), and the resulting code with the new feature
2756 disabled must not need more memory than the old code without your
2757 modification.