README 105 KB
Newer Older
wdenk's avatar
wdenk committed
1
#
wdenk's avatar
wdenk committed
2
# (C) Copyright 2000 - 2004
wdenk's avatar
wdenk committed
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26
# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
#
# See file CREDITS for list of people who contributed to this
# project.
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation; either version 2 of
# the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
# MA 02111-1307 USA
#

Summary:
========

27 28 29 30
This directory contains the source code for U-Boot, a boot loader for
Embedded boards based on PowerPC and ARM processors, which can be
installed in a boot ROM and used to initialize and test the hardware
or to download and run application code.
wdenk's avatar
wdenk committed
31 32

The development of U-Boot is closely related to Linux: some parts of
33 34
the source code originate in the Linux source tree, we have some
header files in common, and special provision has been made to
wdenk's avatar
wdenk committed
35 36 37 38 39 40 41 42 43 44 45 46 47 48
support booting of Linux images.

Some attention has been paid to make this software easily
configurable and extendable. For instance, all monitor commands are
implemented with the same call interface, so that it's very easy to
add new commands. Also, instead of permanently adding rarely used
code (for instance hardware test utilities) to the monitor, you can
load and run it dynamically.


Status:
=======

In general, all boards for which a configuration option exists in the
49
Makefile have been tested to some extent and can be considered
wdenk's avatar
wdenk committed
50 51
"working". In fact, many of them are used in production systems.

52
In case of problems see the CHANGELOG and CREDITS files to find out
wdenk's avatar
wdenk committed
53 54 55 56 57 58
who contributed the specific port.


Where to get help:
==================

59 60 61 62
In case you have questions about, problems with or contributions for
U-Boot you should send a message to the U-Boot mailing list at
<u-boot-users@lists.sourceforge.net>. There is also an archive of
previous traffic on the mailing list - please search the archive
wdenk's avatar
wdenk committed
63 64 65 66 67 68 69 70
before asking FAQ's. Please see
http://lists.sourceforge.net/lists/listinfo/u-boot-users/


Where we come from:
===================

- start from 8xxrom sources
71
- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
wdenk's avatar
wdenk committed
72 73 74 75 76 77 78 79
- clean up code
- make it easier to add custom boards
- make it possible to add other [PowerPC] CPUs
- extend functions, especially:
  * Provide extended interface to Linux boot loader
  * S-Record download
  * network boot
  * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80
- create ARMBoot project (http://sourceforge.net/projects/armboot)
wdenk's avatar
wdenk committed
81
- add other CPU families (starting with ARM)
82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104
- create U-Boot project (http://sourceforge.net/projects/u-boot)


Names and Spelling:
===================

The "official" name of this project is "Das U-Boot". The spelling
"U-Boot" shall be used in all written text (documentation, comments
in source files etc.). Example:

	This is the README file for the U-Boot project.

File names etc. shall be based on the string "u-boot". Examples:

	include/asm-ppc/u-boot.h

	#include <asm/u-boot.h>

Variable names, preprocessor constants etc. shall be either based on
the string "u_boot" or on "U_BOOT". Example:

	U_BOOT_VERSION		u_boot_logo
	IH_OS_U_BOOT		u_boot_hush_start
wdenk's avatar
wdenk committed
105 106


wdenk's avatar
wdenk committed
107 108 109 110 111 112 113 114 115 116 117 118
Versioning:
===========

U-Boot uses a 3 level version number containing a version, a
sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
sub-version "34", and patchlevel "4".

The patchlevel is used to indicate certain stages of development
between released versions, i. e. officially released versions of
U-Boot will always have a patchlevel of "0".


wdenk's avatar
wdenk committed
119 120 121
Directory Hierarchy:
====================

wdenk's avatar
wdenk committed
122 123
- board		Board dependent files
- common	Misc architecture independent functions
wdenk's avatar
wdenk committed
124
- cpu		CPU specific files
wdenk's avatar
wdenk committed
125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145
  - 74xx_7xx	Files specific to Motorola MPC74xx and 7xx CPUs
  - arm720t	Files specific to ARM 720 CPUs
  - arm920t	Files specific to ARM 920 CPUs
  - arm925t	Files specific to ARM 925 CPUs
  - arm926ejs	Files specific to ARM 926 CPUs
  - at91rm9200	Files specific to Atmel AT91RM9200 CPUs
  - i386	Files specific to i386 CPUs
  - ixp		Files specific to Intel XScale IXP CPUs
  - mcf52x2	Files specific to Motorola ColdFire MCF52x2 CPUs
  - mips	Files specific to MIPS CPUs
  - mpc5xx	Files specific to Motorola MPC5xx  CPUs
  - mpc5xxx	Files specific to Motorola MPC5xxx CPUs
  - mpc8xx	Files specific to Motorola MPC8xx  CPUs
  - mpc824x	Files specific to Motorola MPC824x CPUs
  - mpc8260	Files specific to Motorola MPC8260 CPUs
  - mpc85xx	Files specific to Motorola MPC85xx CPUs
  - nios	Files specific to Altera NIOS CPUs
  - ppc4xx	Files specific to IBM PowerPC 4xx CPUs
  - pxa		Files specific to Intel XScale PXA CPUs
  - s3c44b0	Files specific to Samsung S3C44B0 CPUs
  - sa1100	Files specific to Intel StrongARM SA1100 CPUs
wdenk's avatar
wdenk committed
146 147
- disk		Code for disk drive partition handling
- doc		Documentation (don't expect too much)
wdenk's avatar
wdenk committed
148
- drivers	Commonly used device drivers
wdenk's avatar
wdenk committed
149 150 151
- dtt		Digital Thermometer and Thermostat drivers
- examples	Example code for standalone applications, etc.
- include	Header Files
wdenk's avatar
wdenk committed
152 153 154 155 156 157 158
- lib_arm	Files generic to ARM	 architecture
- lib_generic	Files generic to all	 architectures
- lib_i386	Files generic to i386	 architecture
- lib_m68k	Files generic to m68k	 architecture
- lib_mips	Files generic to MIPS	 architecture
- lib_nios	Files generic to NIOS	 architecture
- lib_ppc	Files generic to PowerPC architecture
wdenk's avatar
wdenk committed
159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214
- net		Networking code
- post		Power On Self Test
- rtc		Real Time Clock drivers
- tools		Tools to build S-Record or U-Boot images, etc.

Software Configuration:
=======================

Configuration is usually done using C preprocessor defines; the
rationale behind that is to avoid dead code whenever possible.

There are two classes of configuration variables:

* Configuration _OPTIONS_:
  These are selectable by the user and have names beginning with
  "CONFIG_".

* Configuration _SETTINGS_:
  These depend on the hardware etc. and should not be meddled with if
  you don't know what you're doing; they have names beginning with
  "CFG_".

Later we will add a configuration tool - probably similar to or even
identical to what's used for the Linux kernel. Right now, we have to
do the configuration by hand, which means creating some symbolic
links and editing some configuration files. We use the TQM8xxL boards
as an example here.


Selection of Processor Architecture and Board Type:
---------------------------------------------------

For all supported boards there are ready-to-use default
configurations available; just type "make <board_name>_config".

Example: For a TQM823L module type:

	cd u-boot
	make TQM823L_config

For the Cogent platform, you need to specify the cpu type as well;
e.g. "make cogent_mpc8xx_config". And also configure the cogent
directory according to the instructions in cogent/README.


Configuration Options:
----------------------

Configuration depends on the combination of board and CPU type; all
such information is kept in a configuration file
"include/configs/<board_name>.h".

Example: For a TQM823L module, all configuration settings are in
"include/configs/TQM823L.h".


wdenk's avatar
wdenk committed
215 216 217 218 219
Many of the options are named exactly as the corresponding Linux
kernel configuration options. The intention is to make it easier to
build a config tool - later.


wdenk's avatar
wdenk committed
220 221 222 223 224 225 226
The following options need to be configured:

- CPU Type:	Define exactly one of

		PowerPC based CPUs:
		-------------------
		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860
227
	or	CONFIG_MPC5xx
wdenk's avatar
wdenk committed
228
	or	CONFIG_MPC824X, CONFIG_MPC8260
229
	or	CONFIG_MPC85xx
wdenk's avatar
wdenk committed
230 231
	or	CONFIG_IOP480
	or	CONFIG_405GP
232
	or	CONFIG_405EP
wdenk's avatar
wdenk committed
233 234
	or	CONFIG_440
	or	CONFIG_MPC74xx
wdenk's avatar
wdenk committed
235
	or	CONFIG_750FX
wdenk's avatar
wdenk committed
236 237 238 239 240 241 242 243 244 245 246 247 248

		ARM based CPUs:
		---------------
		CONFIG_SA1110
		CONFIG_ARM7
		CONFIG_PXA250


- Board Type:	Define exactly one of

		PowerPC based boards:
		---------------------

wdenk's avatar
wdenk committed
249 250 251 252 253 254 255 256
		CONFIG_ADCIOP,	   CONFIG_ICU862      CONFIG_RPXsuper,
		CONFIG_ADS860,	   CONFIG_IP860,      CONFIG_SM850,
		CONFIG_AMX860,	   CONFIG_IPHASE4539, CONFIG_SPD823TS,
		CONFIG_AR405,	   CONFIG_IVML24,     CONFIG_SXNI855T,
		CONFIG_BAB7xx,	   CONFIG_IVML24_128, CONFIG_Sandpoint8240,
		CONFIG_CANBT,	   CONFIG_IVML24_256, CONFIG_Sandpoint8245,
		CONFIG_CCM,	   CONFIG_IVMS8,      CONFIG_TQM823L,
		CONFIG_CPCI405,	   CONFIG_IVMS8_128,  CONFIG_TQM850L,
wdenk's avatar
wdenk committed
257 258
		CONFIG_CPCI4052,   CONFIG_IVMS8_256,  CONFIG_TQM855L,
		CONFIG_CPCIISER4,  CONFIG_LANTEC,     CONFIG_TQM860L,
wdenk's avatar
wdenk committed
259 260 261
		CONFIG_CPU86,	   CONFIG_MBX,	      CONFIG_TQM8260,
		CONFIG_CRAYL1,	   CONFIG_MBX860T,    CONFIG_TTTech,
		CONFIG_CU824,	   CONFIG_MHPC,	      CONFIG_UTX8245,
wdenk's avatar
wdenk committed
262
		CONFIG_DASA_SIM,   CONFIG_MIP405,     CONFIG_W7OLMC,
wdenk's avatar
wdenk committed
263 264 265 266 267
		CONFIG_DU405,	   CONFIG_MOUSSE,     CONFIG_W7OLMG,
		CONFIG_ELPPC,	   CONFIG_MPC8260ADS, CONFIG_WALNUT405,
		CONFIG_ERIC,	   CONFIG_MUSENKI,    CONFIG_ZUMA,
		CONFIG_ESTEEM192E, CONFIG_MVS1,	      CONFIG_c2mon,
		CONFIG_ETX094,	   CONFIG_NX823,      CONFIG_cogent_mpc8260,
wdenk's avatar
wdenk committed
268
		CONFIG_EVB64260,   CONFIG_OCRTC,      CONFIG_cogent_mpc8xx,
wdenk's avatar
wdenk committed
269 270
		CONFIG_FADS823,	   CONFIG_ORSG,	      CONFIG_ep8260,
		CONFIG_FADS850SAR, CONFIG_OXC,	      CONFIG_gw8260,
wdenk's avatar
wdenk committed
271
		CONFIG_FADS860T,   CONFIG_PCI405,     CONFIG_hermes,
wdenk's avatar
wdenk committed
272 273 274 275 276 277 278 279 280
		CONFIG_FLAGADM,	   CONFIG_PCIPPC2,    CONFIG_hymod,
		CONFIG_FPS850L,	   CONFIG_PCIPPC6,    CONFIG_lwmon,
		CONFIG_GEN860T,	   CONFIG_PIP405,     CONFIG_pcu_e,
		CONFIG_GENIETV,	   CONFIG_PM826,      CONFIG_ppmc8260,
		CONFIG_GTH,	   CONFIG_RPXClassic, CONFIG_rsdproto,
		CONFIG_IAD210,	   CONFIG_RPXlite,    CONFIG_sbc8260,
		CONFIG_EBONY,	   CONFIG_sacsng,     CONFIG_FPS860L,
		CONFIG_V37,	   CONFIG_ELPT860,    CONFIG_CMI,
		CONFIG_NETVIA,	   CONFIG_RBC823,     CONFIG_ZPC1900,
wdenk's avatar
wdenk committed
281
		CONFIG_MPC8540ADS, CONFIG_MPC8560ADS, CONFIG_QS850,
wdenk's avatar
wdenk committed
282
		CONFIG_QS823,	   CONFIG_QS860T,     CONFIG_DB64360,
283
		CONFIG_DB64460,	   CONFIG_DUET_ADS
wdenk's avatar
wdenk committed
284 285 286 287

		ARM based boards:
		-----------------

288 289 290 291 292 293
		CONFIG_HHP_CRADLE,  CONFIG_DNP1110,	CONFIG_EP7312,
		CONFIG_IMPA7,	    CONFIG_LART,	CONFIG_LUBBOCK,
		CONFIG_INNOVATOROMAP1510,      CONFIG_INNOVATOROMAP1610,
		CONFIG_H2_OMAP1610, CONFIG_SHANNON,	CONFIG_SMDK2400,
		CONFIG_SMDK2410,    CONFIG_TRAB,	CONFIG_VCMA9,
		CONFIG_AT91RM9200DK
wdenk's avatar
wdenk committed
294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316


- CPU Module Type: (if CONFIG_COGENT is defined)
		Define exactly one of
		CONFIG_CMA286_60_OLD
--- FIXME --- not tested yet:
		CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
		CONFIG_CMA287_23, CONFIG_CMA287_50

- Motherboard Type: (if CONFIG_COGENT is defined)
		Define exactly one of
		CONFIG_CMA101, CONFIG_CMA102

- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
		Define one or more of
		CONFIG_CMA302

- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
		Define one or more of
		CONFIG_LCD_HEARTBEAT	- update a character position on
					  the lcd display every second with
					  a "rotator" |\-/|\-/

wdenk's avatar
wdenk committed
317 318 319 320
- Board flavour: (if CONFIG_MPC8260ADS is defined)
		CONFIG_ADSTYPE
		Possible values are:
			CFG_8260ADS	- original MPC8260ADS
321
			CFG_8266ADS	- MPC8266ADS
wdenk's avatar
wdenk committed
322
			CFG_PQ2FADS	- PQ2FADS-ZU or PQ2FADS-VR
wdenk's avatar
wdenk committed
323 324


wdenk's avatar
wdenk committed
325
- MPC824X Family Member (if CONFIG_MPC824X is defined)
wdenk's avatar
wdenk committed
326 327
		Define exactly one of
		CONFIG_MPC8240, CONFIG_MPC8245
wdenk's avatar
wdenk committed
328

329
- 8xx CPU Options: (if using an MPC8xx cpu)
wdenk's avatar
wdenk committed
330
		Define one or more of
wdenk's avatar
wdenk committed
331 332 333
		CONFIG_8xx_GCLK_FREQ	- if get_gclk_freq() cannot work
					  e.g. if there is no 32KHz
					  reference PIT/RTC clock
wdenk's avatar
wdenk committed
334

335 336 337 338 339 340 341 342 343
- 859/866 CPU options: (if using a MPC859 or MPC866 CPU):
		CFG_866_OSCCLK
		CFG_866_CPUCLK_MIN
		CFG_866_CPUCLK_MAX
		CFG_866_CPUCLK_DEFAULT
			See doc/README.MPC866

		CFG_MEASURE_CPUCLK

wdenk's avatar
wdenk committed
344 345 346 347 348 349
		Define this to measure the actual CPU clock instead
		of relying on the correctness of the configured
		values. Mostly useful for board bringup to make sure
		the PLL is locked at the intended frequency. Note
		that this requires a (stable) reference clock (32 kHz
		RTC clock),
350

wdenk's avatar
wdenk committed
351
- Linux Kernel Interface:
wdenk's avatar
wdenk committed
352 353 354 355 356 357 358 359 360 361 362 363 364
		CONFIG_CLOCKS_IN_MHZ

		U-Boot stores all clock information in Hz
		internally. For binary compatibility with older Linux
		kernels (which expect the clocks passed in the
		bd_info data to be in MHz) the environment variable
		"clocks_in_mhz" can be defined so that U-Boot
		converts clock data to MHZ before passing it to the
		Linux kernel.
		When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
		"clocks_in_mhz=1" is  automatically  included  in  the
		default environment.

wdenk's avatar
wdenk committed
365 366 367 368 369 370
		CONFIG_MEMSIZE_IN_BYTES		[relevant for MIPS only]

		When transfering memsize parameter to linux, some versions
		expect it to be in bytes, others in MB.
		Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.

wdenk's avatar
wdenk committed
371
- Console Interface:
372 373 374 375
		Depending on board, define exactly one serial port
		(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
		CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
		console by defining CONFIG_8xx_CONS_NONE
wdenk's avatar
wdenk committed
376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392

		Note: if CONFIG_8xx_CONS_NONE is defined, the serial
		port routines must be defined elsewhere
		(i.e. serial_init(), serial_getc(), ...)

		CONFIG_CFB_CONSOLE
		Enables console device for a color framebuffer. Needs following
		defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
			VIDEO_FB_LITTLE_ENDIAN	graphic memory organisation
						(default big endian)
			VIDEO_HW_RECTFILL	graphic chip supports
						rectangle fill
						(cf. smiLynxEM)
			VIDEO_HW_BITBLT		graphic chip supports
						bit-blit (cf. smiLynxEM)
			VIDEO_VISIBLE_COLS	visible pixel columns
						(cols=pitch)
wdenk's avatar
wdenk committed
393 394
			VIDEO_VISIBLE_ROWS	visible pixel rows
			VIDEO_PIXEL_SIZE	bytes per pixel
wdenk's avatar
wdenk committed
395 396
			VIDEO_DATA_FORMAT	graphic data format
						(0-5, cf. cfb_console.c)
wdenk's avatar
wdenk committed
397
			VIDEO_FB_ADRS		framebuffer address
wdenk's avatar
wdenk committed
398 399 400 401 402 403 404 405 406 407 408 409 410 411 412
			VIDEO_KBD_INIT_FCT	keyboard int fct
						(i.e. i8042_kbd_init())
			VIDEO_TSTC_FCT		test char fct
						(i.e. i8042_tstc)
			VIDEO_GETC_FCT		get char fct
						(i.e. i8042_getc)
			CONFIG_CONSOLE_CURSOR	cursor drawing on/off
						(requires blink timer
						cf. i8042.c)
			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
			CONFIG_CONSOLE_TIME	display time/date info in
						upper right corner
						(requires CFG_CMD_DATE)
			CONFIG_VIDEO_LOGO	display Linux logo in
						upper left corner
413 414 415
			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of
						linux_logo.h for logo.
						Requires CONFIG_VIDEO_LOGO
wdenk's avatar
wdenk committed
416 417 418 419
			CONFIG_CONSOLE_EXTRA_INFO
						addional board info beside
						the logo

420 421 422
		When CONFIG_CFB_CONSOLE is defined, video console is
		default i/o. Serial console can be forced with
		environment 'console=serial'.
wdenk's avatar
wdenk committed
423

wdenk's avatar
wdenk committed
424 425 426 427
		When CONFIG_SILENT_CONSOLE is defined, all console
		messages (by U-Boot and Linux!) can be silenced with
		the "silent" environment variable. See
		doc/README.silent for more information.
wdenk's avatar
wdenk committed
428

wdenk's avatar
wdenk committed
429 430 431 432
- Console Baudrate:
		CONFIG_BAUDRATE - in bps
		Select one of the baudrates listed in
		CFG_BAUDRATE_TABLE, see below.
wdenk's avatar
wdenk committed
433
		CFG_BRGCLK_PRESCALE, baudrate prescale
wdenk's avatar
wdenk committed
434 435 436 437 438 439 440 441 442 443 444 445 446

- Interrupt driven serial port input:
		CONFIG_SERIAL_SOFTWARE_FIFO

		PPC405GP only.
		Use an interrupt handler for receiving data on the
		serial port. It also enables using hardware handshake
		(RTS/CTS) and UART's built-in FIFO. Set the number of
		bytes the interrupt driven input buffer should have.

		Set to 0 to disable this feature (this is the default).
		This will also disable hardware handshake.

stroese's avatar
stroese committed
447 448 449 450 451 452 453
- Console UART Number:
		CONFIG_UART1_CONSOLE

		IBM PPC4xx only.
		If defined internal UART1 (and not UART0) is used
		as default U-Boot console.

wdenk's avatar
wdenk committed
454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478
- Boot Delay:	CONFIG_BOOTDELAY - in seconds
		Delay before automatically booting the default image;
		set to -1 to disable autoboot.

		See doc/README.autoboot for these options that
		work with CONFIG_BOOTDELAY. None are required.
		CONFIG_BOOT_RETRY_TIME
		CONFIG_BOOT_RETRY_MIN
		CONFIG_AUTOBOOT_KEYED
		CONFIG_AUTOBOOT_PROMPT
		CONFIG_AUTOBOOT_DELAY_STR
		CONFIG_AUTOBOOT_STOP_STR
		CONFIG_AUTOBOOT_DELAY_STR2
		CONFIG_AUTOBOOT_STOP_STR2
		CONFIG_ZERO_BOOTDELAY_CHECK
		CONFIG_RESET_TO_RETRY

- Autoboot Command:
		CONFIG_BOOTCOMMAND
		Only needed when CONFIG_BOOTDELAY is enabled;
		define a command string that is automatically executed
		when no character is read on the console interface
		within "Boot Delay" after reset.

		CONFIG_BOOTARGS
479 480 481
		This can be used to pass arguments to the bootm
		command. The value of CONFIG_BOOTARGS goes into the
		environment value "bootargs".
wdenk's avatar
wdenk committed
482 483

		CONFIG_RAMBOOT and CONFIG_NFSBOOT
484 485 486 487
		The value of these goes into the environment as
		"ramboot" and "nfsboot" respectively, and can be used
		as a convenience, when switching between booting from
		ram and nfs.
wdenk's avatar
wdenk committed
488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529

- Pre-Boot Commands:
		CONFIG_PREBOOT

		When this option is #defined, the existence of the
		environment variable "preboot" will be checked
		immediately before starting the CONFIG_BOOTDELAY
		countdown and/or running the auto-boot command resp.
		entering interactive mode.

		This feature is especially useful when "preboot" is
		automatically generated or modified. For an example
		see the LWMON board specific code: here "preboot" is
		modified when the user holds down a certain
		combination of keys on the (special) keyboard when
		booting the systems

- Serial Download Echo Mode:
		CONFIG_LOADS_ECHO
		If defined to 1, all characters received during a
		serial download (using the "loads" command) are
		echoed back. This might be needed by some terminal
		emulations (like "cu"), but may as well just take
		time on others. This setting #define's the initial
		value of the "loads_echo" environment variable.

- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
		CONFIG_KGDB_BAUDRATE
		Select one of the baudrates listed in
		CFG_BAUDRATE_TABLE, see below.

- Monitor Functions:
		CONFIG_COMMANDS
		Most monitor functions can be selected (or
		de-selected) by adjusting the definition of
		CONFIG_COMMANDS; to select individual functions,
		#define CONFIG_COMMANDS by "OR"ing any of the
		following values:

		#define enables commands:
		-------------------------
		CFG_CMD_ASKENV	* ask for env variable
wdenk's avatar
wdenk committed
530
		CFG_CMD_AUTOSCRIPT Autoscript Support
wdenk's avatar
wdenk committed
531 532
		CFG_CMD_BDI	  bdinfo
		CFG_CMD_BEDBUG	  Include BedBug Debugger
wdenk's avatar
wdenk committed
533
		CFG_CMD_BMP	* BMP support
wdenk's avatar
wdenk committed
534 535 536 537 538
		CFG_CMD_BOOTD	  bootd
		CFG_CMD_CACHE	  icache, dcache
		CFG_CMD_CONSOLE	  coninfo
		CFG_CMD_DATE	* support for RTC, date/time...
		CFG_CMD_DHCP	  DHCP support
wdenk's avatar
wdenk committed
539 540 541
		CFG_CMD_DIAG	* Diagnostics
		CFG_CMD_DOC	* Disk-On-Chip Support
		CFG_CMD_DTT	  Digital Therm and Thermostat
wdenk's avatar
wdenk committed
542 543 544 545 546
		CFG_CMD_ECHO	* echo arguments
		CFG_CMD_EEPROM	* EEPROM read/write support
		CFG_CMD_ELF	  bootelf, bootvx
		CFG_CMD_ENV	  saveenv
		CFG_CMD_FDC	* Floppy Disk Support
547
		CFG_CMD_FAT	  FAT partition support
548
		CFG_CMD_FDOS	* Dos diskette Support
wdenk's avatar
wdenk committed
549 550
		CFG_CMD_FLASH	  flinfo, erase, protect
		CFG_CMD_FPGA	  FPGA device initialization support
wdenk's avatar
wdenk committed
551
		CFG_CMD_HWFLOW	* RTS/CTS hw flow control
wdenk's avatar
wdenk committed
552 553 554
		CFG_CMD_I2C	* I2C serial bus support
		CFG_CMD_IDE	* IDE harddisk support
		CFG_CMD_IMI	  iminfo
wdenk's avatar
wdenk committed
555
		CFG_CMD_IMLS	  List all found images
wdenk's avatar
wdenk committed
556 557
		CFG_CMD_IMMAP	* IMMR dump support
		CFG_CMD_IRQ	* irqinfo
wdenk's avatar
wdenk committed
558
		CFG_CMD_ITEST	* Integer/string test of 2 values
wdenk's avatar
wdenk committed
559
		CFG_CMD_JFFS2	* JFFS2 Support
wdenk's avatar
wdenk committed
560 561 562 563 564
		CFG_CMD_KGDB	* kgdb
		CFG_CMD_LOADB	  loadb
		CFG_CMD_LOADS	  loads
		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
				  loop, mtest
wdenk's avatar
wdenk committed
565
		CFG_CMD_MISC	  Misc functions like sleep etc
566
		CFG_CMD_MMC	  MMC memory mapped support
wdenk's avatar
wdenk committed
567
		CFG_CMD_MII	  MII utility commands
wdenk's avatar
wdenk committed
568
		CFG_CMD_NAND	* NAND support
wdenk's avatar
wdenk committed
569 570 571
		CFG_CMD_NET	  bootp, tftpboot, rarpboot
		CFG_CMD_PCI	* pciinfo
		CFG_CMD_PCMCIA	* PCMCIA support
wdenk's avatar
wdenk committed
572 573
		CFG_CMD_PING	* send ICMP ECHO_REQUEST to network host
		CFG_CMD_PORTIO	* Port I/O
wdenk's avatar
wdenk committed
574 575
		CFG_CMD_REGINFO * Register dump
		CFG_CMD_RUN	  run command in env variable
wdenk's avatar
wdenk committed
576
		CFG_CMD_SAVES	  save S record dump
wdenk's avatar
wdenk committed
577
		CFG_CMD_SCSI	* SCSI Support
wdenk's avatar
wdenk committed
578
		CFG_CMD_SDRAM	* print SDRAM configuration information
wdenk's avatar
wdenk committed
579 580 581
		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
		CFG_CMD_SPI	* SPI serial bus support
		CFG_CMD_USB	* USB support
wdenk's avatar
wdenk committed
582
		CFG_CMD_VFD	* VFD support (TRAB)
wdenk's avatar
wdenk committed
583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603
		CFG_CMD_BSP	* Board SPecific functions
		-----------------------------------------------
		CFG_CMD_ALL	all

		CFG_CMD_DFL	Default configuration; at the moment
				this is includes all commands, except
				the ones marked with "*" in the list
				above.

		If you don't define CONFIG_COMMANDS it defaults to
		CFG_CMD_DFL in include/cmd_confdefs.h. A board can
		override the default settings in the respective
		include file.

		EXAMPLE: If you want all functions except of network
		support you can write:

		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)


	Note:	Don't enable the "icache" and "dcache" commands
604 605 606 607 608 609 610
		(configuration option CFG_CMD_CACHE) unless you know
		what you (and your U-Boot users) are doing. Data
		cache cannot be enabled on systems like the 8xx or
		8260 (where accesses to the IMMR region must be
		uncached), and it cannot be disabled on all other
		systems where we (mis-) use the data cache to hold an
		initial stack and some data.
wdenk's avatar
wdenk committed
611 612 613 614 615 616 617


		XXX - this list needs to get updated!

- Watchdog:
		CONFIG_WATCHDOG
		If this variable is defined, it enables watchdog
wdenk's avatar
wdenk committed
618
		support. There must be support in the platform specific
wdenk's avatar
wdenk committed
619 620 621 622
		code for a watchdog. For the 8xx and 8260 CPUs, the
		SIU Watchdog feature is enabled in the SYPCR
		register.

623 624 625 626 627 628 629
- U-Boot Version:
		CONFIG_VERSION_VARIABLE
		If this variable is defined, an environment variable
		named "ver" is created by U-Boot showing the U-Boot
		version as printed by the "version" command.
		This variable is readonly.

wdenk's avatar
wdenk committed
630 631 632 633 634 635 636 637 638
- Real-Time Clock:

		When CFG_CMD_DATE is selected, the type of the RTC
		has to be selected, too. Define exactly one of the
		following options:

		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx
		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC
		CONFIG_RTC_MC146818	- use MC146818 RTC
wdenk's avatar
wdenk committed
639
		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
wdenk's avatar
wdenk committed
640
		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
641
		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
wdenk's avatar
wdenk committed
642
		CONFIG_RTC_DS164x	- use Dallas DS164x RTC
wdenk's avatar
wdenk committed
643

wdenk's avatar
wdenk committed
644 645 646
		Note that if the RTC uses I2C, then the I2C interface
		must also be configured. See I2C Support, below.

wdenk's avatar
wdenk committed
647 648
- Timestamp Support:

649 650 651 652
		When CONFIG_TIMESTAMP is selected, the timestamp
		(date and time) of an image is printed by image
		commands like bootm or iminfo. This option is
		automatically enabled when you select CFG_CMD_DATE .
wdenk's avatar
wdenk committed
653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672

- Partition Support:
		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
		and/or CONFIG_ISO_PARTITION

		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or
		CFG_CMD_SCSI) you must configure support for at least
		one partition type as well.

- IDE Reset method:
		CONFIG_IDE_RESET_ROUTINE

		Set this to define that instead of a reset Pin, the
		routine ide_set_reset(int idereset) will be used.

- ATAPI Support:
		CONFIG_ATAPI

		Set this to enable ATAPI support.

673 674 675 676 677 678 679 680 681 682 683 684
- LBA48 Support
		CONFIG_LBA48

		Set this to enable support for disks larger than 137GB
		Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
		Whithout these , LBA48 support uses 32bit variables and will 'only'
		support disks up to 2.1TB.

		CFG_64BIT_LBA:
			When enabled, makes the IDE subsystem use 64bit sector addresses.
			Default is 32bit.

wdenk's avatar
wdenk committed
685 686 687 688 689 690 691 692 693 694 695 696 697
- SCSI Support:
		At the moment only there is only support for the
		SYM53C8XX SCSI controller; define
		CONFIG_SCSI_SYM53C8XX to enable it.

		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
		CFG_SCSI_MAX_LUN] can be adjusted to define the
		maximum numbers of LUNs, SCSI ID's and target
		devices.
		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)

- NETWORK Support (PCI):
698 699
		CONFIG_E1000
		Support for Intel 8254x gigabit chips.
stroese's avatar
stroese committed
700

wdenk's avatar
wdenk committed
701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716
		CONFIG_EEPRO100
		Support for Intel 82557/82559/82559ER chips.
		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
		write routine for first time initialisation.

		CONFIG_TULIP
		Support for Digital 2114x chips.
		Optional CONFIG_TULIP_SELECT_MEDIA for board specific
		modem chip initialisation (KS8761/QS6611).

		CONFIG_NATSEMI
		Support for National dp83815 chips.

		CONFIG_NS8382X
		Support for National dp8382[01] gigabit chips.

wdenk's avatar
wdenk committed
717 718 719 720 721 722 723 724 725 726 727 728
- NETWORK Support (other):

		CONFIG_DRIVER_LAN91C96
		Support for SMSC's LAN91C96 chips.

			CONFIG_LAN91C96_BASE
			Define this to hold the physical address
			of the LAN91C96's I/O space

			CONFIG_LAN91C96_USE_32_BIT
			Define this to enable 32 bit addressing

wdenk's avatar
wdenk committed
729 730 731 732 733 734 735 736 737 738 739
- USB Support:
		At the moment only the UHCI host controller is
		supported (PIP405, MIP405); define
		CONFIG_USB_UHCI to enable it.
		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
		end define CONFIG_USB_STORAGE to enable the USB
		storage devices.
		Note:
		Supported are USB Keyboards and USB Floppy drives
		(TEAC FD-05PUB).

740
- MMC Support:
wdenk's avatar
wdenk committed
741 742 743
		The MMC controller on the Intel PXA is supported. To
		enable this define CONFIG_MMC. The MMC can be
		accessed from the boot prompt by mapping the device
744 745
		to physical memory similar to flash. Command line is
		enabled with CFG_CMD_MMC. The MMC driver also works with
wdenk's avatar
wdenk committed
746
		the FAT fs. This is enabled with CFG_CMD_FAT.
747

wdenk's avatar
wdenk committed
748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775
- Keyboard Support:
		CONFIG_ISA_KEYBOARD

		Define this to enable standard (PC-Style) keyboard
		support

		CONFIG_I8042_KBD
		Standard PC keyboard driver with US (is default) and
		GERMAN key layout (switch via environment 'keymap=de') support.
		Export function i8042_kbd_init, i8042_tstc and i8042_getc
		for cfb_console. Supports cursor blinking.

- Video support:
		CONFIG_VIDEO

		Define this to enable video support (for output to
		video).

		CONFIG_VIDEO_CT69000

		Enable Chips & Technologies 69000 Video chip

		CONFIG_VIDEO_SMI_LYNXEM
		Enable Silicon Motion SMI 712/710/810 Video chip
		Videomode are selected via environment 'videomode' with
		standard LiLo mode numbers.
		Following modes are supported  (* is default):

776
			    800x600  1024x768  1280x1024
wdenk's avatar
wdenk committed
777 778 779
	      256  (8bit)     303*	305	  307
	    65536 (16bit)     314	317	  31a
	16,7 Mill (24bit)     315	318	  31b
wdenk's avatar
wdenk committed
780 781
		(i.e. setenv videomode 317; saveenv; reset;)

782
		CONFIG_VIDEO_SED13806
783
		Enable Epson SED13806 driver. This driver supports 8bpp
784 785 786
		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
		or CONFIG_VIDEO_SED13806_16BPP

787
- Keyboard Support:
wdenk's avatar
wdenk committed
788
		CONFIG_KEYBOARD
789

wdenk's avatar
wdenk committed
790 791 792 793
		Define this to enable a custom keyboard support.
		This simply calls drv_keyboard_init() which must be
		defined in your board-specific files.
		The only board using this so far is RBC823.
794

wdenk's avatar
wdenk committed
795 796 797 798 799 800
- LCD Support:	CONFIG_LCD

		Define this to enable LCD support (for output to LCD
		display); also select one of the supported displays
		by defining one of these:

wdenk's avatar
wdenk committed
801
		CONFIG_NEC_NL6448AC33:
wdenk's avatar
wdenk committed
802

wdenk's avatar
wdenk committed
803
			NEC NL6448AC33-18. Active, color, single scan.
wdenk's avatar
wdenk committed
804

wdenk's avatar
wdenk committed
805
		CONFIG_NEC_NL6448BC20
wdenk's avatar
wdenk committed
806

wdenk's avatar
wdenk committed
807 808 809 810 811 812
			NEC NL6448BC20-08. 6.5", 640x480.
			Active, color, single scan.

		CONFIG_NEC_NL6448BC33_54

			NEC NL6448BC33-54. 10.4", 640x480.
wdenk's avatar
wdenk committed
813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842
			Active, color, single scan.

		CONFIG_SHARP_16x9

			Sharp 320x240. Active, color, single scan.
			It isn't 16x9, and I am not sure what it is.

		CONFIG_SHARP_LQ64D341

			Sharp LQ64D341 display, 640x480.
			Active, color, single scan.

		CONFIG_HLD1045

			HLD1045 display, 640x480.
			Active, color, single scan.

		CONFIG_OPTREX_BW

			Optrex	 CBL50840-2 NF-FW 99 22 M5
			or
			Hitachi	 LMG6912RPFC-00T
			or
			Hitachi	 SP14Q002

			320x240. Black & white.

		Normally display is black on white background; define
		CFG_WHITE_ON_BLACK to get it inverted.

wdenk's avatar
wdenk committed
843
- Splash Screen Support: CONFIG_SPLASH_SCREEN
844

wdenk's avatar
wdenk committed
845 846 847 848 849 850 851 852
		If this option is set, the environment is checked for
		a variable "splashimage". If found, the usual display
		of logo, copyright and system information on the LCD
		is supressed and the BMP image at the address
		specified in "splashimage" is loaded instead. The
		console is redirected to the "nulldev", too. This
		allows for a "silent" boot where a splash screen is
		loaded very quickly after power-on.
853

wdenk's avatar
wdenk committed
854 855 856 857 858 859 860
- Compression support:
		CONFIG_BZIP2

		If this option is set, support for bzip2 compressed
		images is included. If not, only uncompressed and gzip
		compressed images are supported.

861 862 863
		NOTE: the bzip2 algorithm requires a lot of RAM, so
		the malloc area (as defined by CFG_MALLOC_LEN) should
		be at least 4MB.
864

wdenk's avatar
wdenk committed
865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905
- Ethernet address:
		CONFIG_ETHADDR
		CONFIG_ETH2ADDR
		CONFIG_ETH3ADDR

		Define a default value for ethernet address to use
		for the respective ethernet interface, in case this
		is not determined automatically.

- IP address:
		CONFIG_IPADDR

		Define a default value for the IP address to use for
		the default ethernet interface, in case this is not
		determined through e.g. bootp.

- Server IP address:
		CONFIG_SERVERIP

		Defines a default value for theIP address of a TFTP
		server to contact when using the "tftboot" command.

- BOOTP Recovery Mode:
		CONFIG_BOOTP_RANDOM_DELAY

		If you have many targets in a network that try to
		boot using BOOTP, you may want to avoid that all
		systems send out BOOTP requests at precisely the same
		moment (which would happen for instance at recovery
		from a power failure, when all systems will try to
		boot, thus flooding the BOOTP server. Defining
		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
		inserted before sending out BOOTP requests. The
		following delays are insterted then:

		1st BOOTP request:	delay 0 ... 1 sec
		2nd BOOTP request:	delay 0 ... 2 sec
		3rd BOOTP request:	delay 0 ... 4 sec
		4th and following
		BOOTP requests:		delay 0 ... 8 sec

906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928
- DHCP Advanced Options:
		CONFIG_BOOTP_MASK

		You can fine tune the DHCP functionality by adding
		these flags to the CONFIG_BOOTP_MASK define:

		CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
		serverip from a DHCP server, it is possible that more
		than one DNS serverip is offered to the client.
		If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
		serverip will be stored in the additional environment
		variable "dnsip2". The first DNS serverip is always
		stored in the variable "dnsip", when CONFIG_BOOTP_DNS
		is added to the CONFIG_BOOTP_MASK.

		CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
		to do a dynamic update of a DNS server. To do this, they
		need the hostname of the DHCP requester.
		If CONFIG_BOOP_SEND_HOSTNAME is added to the
		CONFIG_BOOTP_MASK, the content of the "hostname"
		environment variable is passed as option 12 to
		the DHCP server.

wdenk's avatar
wdenk committed
929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947
- Status LED:	CONFIG_STATUS_LED

		Several configurations allow to display the current
		status using a LED. For instance, the LED will blink
		fast while running U-Boot code, stop blinking as
		soon as a reply to a BOOTP request was received, and
		start blinking slow once the Linux kernel is running
		(supported by a status LED driver in the Linux
		kernel). Defining CONFIG_STATUS_LED enables this
		feature in U-Boot.

- CAN Support:	CONFIG_CAN_DRIVER

		Defining CONFIG_CAN_DRIVER enables CAN driver support
		on those systems that support this (optional)
		feature, like the TQM8xxL modules.

- I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C

wdenk's avatar
wdenk committed
948
		These enable I2C serial bus commands. Defining either of
949 950
		(but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
		include the appropriate I2C driver for the selected cpu.
wdenk's avatar
wdenk committed
951

952 953
		This will allow you to use i2c commands at the u-boot
		command line (as long as you set CFG_CMD_I2C in
wdenk's avatar
wdenk committed
954 955
		CONFIG_COMMANDS) and communicate with i2c based realtime
		clock chips. See common/cmd_i2c.c for a description of the
956
		command line interface.
wdenk's avatar
wdenk committed
957

wdenk's avatar
wdenk committed
958
		CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
wdenk's avatar
wdenk committed
959

960
		CONFIG_SOFT_I2C configures u-boot to use a software (aka
wdenk's avatar
wdenk committed
961 962
		bit-banging) driver instead of CPM or similar hardware
		support for I2C.
wdenk's avatar
wdenk committed
963

964
		There are several other quantities that must also be
wdenk's avatar
wdenk committed
965
		defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
wdenk's avatar
wdenk committed
966

wdenk's avatar
wdenk committed
967
		In both cases you will need to define CFG_I2C_SPEED
968 969 970 971
		to be the frequency (in Hz) at which you wish your i2c bus
		to run and CFG_I2C_SLAVE to be the address of this node (ie
		the cpu's i2c node address).

wdenk's avatar
wdenk committed
972 973 974
		Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
		sets the cpu up as a master node and so its address should
		therefore be cleared to 0 (See, eg, MPC823e User's Manual
975
		p.16-473). So, set CFG_I2C_SLAVE to 0.
wdenk's avatar
wdenk committed
976

977
		That's all that's required for CONFIG_HARD_I2C.
wdenk's avatar
wdenk committed
978

wdenk's avatar
wdenk committed
979 980 981
		If you use the software i2c interface (CONFIG_SOFT_I2C)
		then the following macros need to be defined (examples are
		from include/configs/lwmon.h):
wdenk's avatar
wdenk committed
982 983 984

		I2C_INIT

wdenk's avatar
wdenk committed
985
		(Optional). Any commands necessary to enable the I2C
986
		controller or configure ports.
wdenk's avatar
wdenk committed
987

wdenk's avatar
wdenk committed
988
		eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |=	PB_SCL)
wdenk's avatar
wdenk committed
989

wdenk's avatar
wdenk committed
990 991
		I2C_PORT

992 993 994
		(Only for MPC8260 CPU). The I/O port to use (the code
		assumes both bits are on the same port). Valid values
		are 0..3 for ports A..D.
wdenk's avatar
wdenk committed
995 996 997 998 999 1000 1001

		I2C_ACTIVE

		The code necessary to make the I2C data line active
		(driven).  If the data line is open collector, this
		define can be null.

wdenk's avatar
wdenk committed
1002 1003
		eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |=  PB_SDA)

wdenk's avatar
wdenk committed
1004 1005 1006 1007 1008 1009
		I2C_TRISTATE

		The code necessary to make the I2C data line tri-stated
		(inactive).  If the data line is open collector, this
		define can be null.

wdenk's avatar
wdenk committed
1010 1011
		eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)

wdenk's avatar
wdenk committed
1012 1013 1014 1015 1016
		I2C_READ

		Code that returns TRUE if the I2C data line is high,
		FALSE if it is low.

wdenk's avatar
wdenk committed
1017 1018
		eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)

wdenk's avatar
wdenk committed
1019 1020 1021 1022 1023
		I2C_SDA(bit)

		If <bit> is TRUE, sets the I2C data line high. If it
		is FALSE, it clears it (low).

wdenk's avatar
wdenk committed
1024
		eg: #define I2C_SDA(bit) \
wdenk's avatar
wdenk committed
1025
			if(bit) immr->im_cpm.cp_pbdat |=  PB_SDA; \
wdenk's avatar
wdenk committed
1026
			else	immr->im_cpm.cp_pbdat &= ~PB_SDA
wdenk's avatar
wdenk committed
1027

wdenk's avatar
wdenk committed
1028 1029 1030 1031 1032
		I2C_SCL(bit)

		If <bit> is TRUE, sets the I2C clock line high. If it
		is FALSE, it clears it (low).

wdenk's avatar
wdenk committed
1033
		eg: #define I2C_SCL(bit) \
wdenk's avatar
wdenk committed
1034
			if(bit) immr->im_cpm.cp_pbdat |=  PB_SCL; \
wdenk's avatar
wdenk committed
1035
			else	immr->im_cpm.cp_pbdat &= ~PB_SCL
wdenk's avatar
wdenk committed
1036

wdenk's avatar
wdenk committed
1037 1038 1039 1040
		I2C_DELAY

		This delay is invoked four times per clock cycle so this
		controls the rate of data transfer.  The data rate thus
wdenk's avatar
wdenk committed
1041
		is 1 / (I2C_DELAY * 4). Often defined to be something
1042 1043
		like:

wdenk's avatar
wdenk committed
1044
		#define I2C_DELAY  udelay(2)
wdenk's avatar
wdenk committed
1045

1046 1047
		CFG_I2C_INIT_BOARD

wdenk's avatar
wdenk committed
1048 1049 1050 1051 1052 1053 1054 1055
		When a board is reset during an i2c bus transfer
		chips might think that the current transfer is still
		in progress. On some boards it is possible to access
		the i2c SCLK line directly, either by using the
		processor pin as a GPIO or by having a second pin
		connected to the bus. If this option is defined a
		custom i2c_init_board() routine in boards/xxx/board.c
		is run early in the boot sequence.
1056

wdenk's avatar
wdenk committed
1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069
- SPI Support:	CONFIG_SPI

		Enables SPI driver (so far only tested with
		SPI EEPROM, also an instance works with Crystal A/D and
		D/As on the SACSng board)

		CONFIG_SPI_X

		Enables extended (16-bit) SPI EEPROM addressing.
		(symmetrical to CONFIG_I2C_X)

		CONFIG_SOFT_SPI

1070 1071 1072 1073 1074 1075 1076
		Enables a software (bit-bang) SPI driver rather than
		using hardware support. This is a general purpose
		driver that only requires three general I/O port pins
		(two outputs, one input) to function. If this is
		defined, the board configuration must define several
		SPI configuration items (port pins to use, etc). For
		an example, see include/configs/sacsng.h.
wdenk's avatar
wdenk committed
1077

wdenk's avatar
wdenk committed
1078
- FPGA Support: CONFIG_FPGA_COUNT
wdenk's avatar
wdenk committed
1079

wdenk's avatar
wdenk committed
1080
		Specify the number of FPGA devices to support.
wdenk's avatar
wdenk committed
1081

wdenk's avatar
wdenk committed
1082
		CONFIG_FPGA
wdenk's avatar
wdenk committed
1083

wdenk's avatar
wdenk committed
1084 1085
		Used to specify the types of FPGA devices.  For example,
		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
wdenk's avatar
wdenk committed
1086

wdenk's avatar
wdenk committed
1087
		CFG_FPGA_PROG_FEEDBACK
wdenk's avatar
wdenk committed
1088

wdenk's avatar
wdenk committed
1089
		Enable printing of hash marks during FPGA configuration.
wdenk's avatar
wdenk committed
1090 1091 1092

		CFG_FPGA_CHECK_BUSY

1093 1094 1095 1096
		Enable checks on FPGA configuration interface busy
		status by the configuration function. This option
		will require a board or device specific function to
		be written.
wdenk's avatar
wdenk committed
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107

		CONFIG_FPGA_DELAY

		If defined, a function that provides delays in the FPGA
		configuration driver.

		CFG_FPGA_CHECK_CTRLC
		Allow Control-C to interrupt FPGA configuration

		CFG_FPGA_CHECK_ERROR

1108 1109 1110 1111
		Check for configuration errors during FPGA bitfile
		loading. For example, abort during Virtex II
		configuration if the INIT_B line goes low (which
		indicated a CRC error).
wdenk's avatar
wdenk committed
1112 1113 1114

		CFG_FPGA_WAIT_INIT

1115 1116 1117 1118
		Maximum time to wait for the INIT_B line to deassert
		after PROB_B has been deasserted during a Virtex II
		FPGA configuration sequence. The default time is 500
		mS.
wdenk's avatar
wdenk committed
1119 1120 1121

		CFG_FPGA_WAIT_BUSY

1122 1123
		Maximum time to wait for BUSY to deassert during
		Virtex II FPGA configuration. The default is 5 mS.
wdenk's avatar
wdenk committed
1124 1125 1126

		CFG_FPGA_WAIT_CONFIG

1127 1128
		Time to wait after FPGA configuration. The default is
		200 mS.
wdenk's avatar
wdenk committed
1129 1130 1131 1132

- Configuration Management:
		CONFIG_IDENT_STRING

1133 1134
		If defined, this string will be added to the U-Boot
		version information (U_BOOT_VERSION)
wdenk's avatar
wdenk committed
1135 1136 1137

- Vendor Parameter Protection:

1138 1139
		U-Boot considers the values of the environment
		variables "serial#" (Board Serial Number) and
wdenk's avatar
wdenk committed
1140
		"ethaddr" (Ethernet Address) to be parameters that
1141 1142 1143 1144 1145
		are set once by the board vendor / manufacturer, and
		protects these variables from casual modification by
		the user. Once set, these variables are read-only,
		and write or delete attempts are rejected. You can
		change this behviour:
wdenk's avatar
wdenk committed
1146 1147 1148

		If CONFIG_ENV_OVERWRITE is #defined in your config
		file, the write protection for vendor parameters is
1149
		completely disabled. Anybody can change or delete
wdenk's avatar
wdenk committed
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204
		these parameters.

		Alternatively, if you #define _both_ CONFIG_ETHADDR
		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
		ethernet address is installed in the environment,
		which can be changed exactly ONCE by the user. [The
		serial# is unaffected by this, i. e. it remains
		read-only.]

- Protected RAM:
		CONFIG_PRAM

		Define this variable to enable the reservation of
		"protected RAM", i. e. RAM which is not overwritten
		by U-Boot. Define CONFIG_PRAM to hold the number of
		kB you want to reserve for pRAM. You can overwrite
		this default value by defining an environment
		variable "pram" to the number of kB you want to
		reserve. Note that the board info structure will
		still show the full amount of RAM. If pRAM is
		reserved, a new environment variable "mem" will
		automatically be defined to hold the amount of
		remaining RAM in a form that can be passed as boot
		argument to Linux, for instance like that:

			setenv bootargs ... mem=\$(mem)
			saveenv

		This way you can tell Linux not to use this memory,
		either, which results in a memory region that will
		not be affected by reboots.

		*WARNING* If your board configuration uses automatic
		detection of the RAM size, you must make sure that
		this memory test is non-destructive. So far, the
		following board configurations are known to be
		"pRAM-clean":

			ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
			HERMES, IP860, RPXlite, LWMON, LANTEC,
			PCU_E, FLAGADM, TQM8260

- Error Recovery:
		CONFIG_PANIC_HANG

		Define this variable to stop the system in case of a
		fatal error, so that you have to reset it manually.
		This is probably NOT a good idea for an embedded
		system where you want to system to reboot
		automatically as fast as possible, but it may be
		useful during development since you can try to debug
		the conditions that lead to the situation.

		CONFIG_NET_RETRY_COUNT

1205 1206 1207 1208
		This variable defines the number of retries for
		network operations like ARP, RARP, TFTP, or BOOTP
		before giving up the operation. If not defined, a
		default value of 5 is used.
wdenk's avatar
wdenk committed
1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230

- Command Interpreter:
		CFG_HUSH_PARSER

		Define this variable to enable the "hush" shell (from
		Busybox) as command line interpreter, thus enabling
		powerful command line syntax like
		if...then...else...fi conditionals or `&&' and '||'
		constructs ("shell scripts").

		If undefined, you get the old, much simpler behaviour
		with a somewhat smaller memory footprint.


		CFG_PROMPT_HUSH_PS2

		This defines the secondary prompt string, which is
		printed when the command interpreter needs more input
		to complete a command. Usually "> ".

	Note:

wdenk's avatar
wdenk committed
1231 1232 1233 1234 1235 1236 1237
		In the current implementation, the local variables
		space and global environment variables space are
		separated. Local variables are those you define by
		simply typing `name=value'. To access a local
		variable later on, you have write `$name' or
		`${name}'; to execute the contents of a variable
		directly type `$name' at the command prompt.
wdenk's avatar
wdenk committed
1238

1239 1240 1241 1242
		Global environment variables are those you use
		setenv/printenv to work with. To run a command stored
		in such a variable, you need to use the run command,
		and you must not use the '$' sign to access them.
wdenk's avatar
wdenk committed
1243 1244 1245 1246 1247 1248 1249

		To store commands and special characters in a
		variable, please use double quotation marks
		surrounding the whole text of the variable, instead
		of the backslashes before semicolons and special
		symbols.

wdenk's avatar
wdenk committed
1250
- Default Environment:
wdenk's avatar
wdenk committed
1251 1252
		CONFIG_EXTRA_ENV_SETTINGS

1253 1254
		Define this to contain any number of null terminated
		strings (variable = value pairs) that will be part of
wdenk's avatar
wdenk committed
1255
		the default environment compiled into the boot image.
1256

1257 1258
		For example, place something like this in your
		board's config file:
wdenk's avatar
wdenk committed
1259 1260 1261 1262 1263

		#define CONFIG_EXTRA_ENV_SETTINGS \
			"myvar1=value1\0" \
			"myvar2=value2\0"

1264 1265 1266 1267
		Warning: This method is based on knowledge about the
		internal format how the environment is stored by the
		U-Boot code. This is NOT an official, exported
		interface! Although it is unlikely that this format
wdenk's avatar
wdenk committed
1268
		will change soon, there is no guarantee either.
wdenk's avatar
wdenk committed
1269 1270
		You better know what you are doing here.

1271 1272 1273 1274
		Note: overly (ab)use of the default environment is
		discouraged. Make sure to check other ways to preset
		the environment like the autoscript function or the
		boot command first.
wdenk's avatar
wdenk committed
1275

wdenk's avatar
wdenk committed
1276
- DataFlash Support:
1277 1278
		CONFIG_HAS_DATAFLASH

wdenk's avatar
wdenk committed
1279 1280 1281
		Defining this option enables DataFlash features and
		allows to read/write in Dataflash via the standard
		commands cp, md...
1282

wdenk's avatar
wdenk committed
1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296
- SystemACE Support:
		CONFIG_SYSTEMACE

		Adding this option adds support for Xilinx SystemACE
		chips attached via some sort of local bus. The address
		of the chip must alsh be defined in the
		CFG_SYSTEMACE_BASE macro. For example:

		#define CONFIG_SYSTEMACE
		#define CFG_SYSTEMACE_BASE 0xf0000000

		When SystemACE support is added, the "ace" device type
		becomes available to the fat commands, i.e. fatls.

wdenk's avatar
wdenk committed
1297
- Show boot progress:
wdenk's avatar
wdenk committed
1298 1299
		CONFIG_SHOW_BOOT_PROGRESS

1300 1301 1302 1303 1304 1305
		Defining this option allows to add some board-
		specific code (calling a user-provided function
		"show_boot_progress(int)") that enables you to show
		the system's boot progress on some display (for
		example, some LED's) on your board. At the moment,
		the following checkpoints are implemented:
wdenk's avatar
wdenk committed
1306 1307 1308

  Arg	Where			When
    1	common/cmd_bootm.c	before attempting to boot an image
wdenk's avatar
wdenk committed
1309
   -1	common/cmd_bootm.c	Image header has bad	 magic number
wdenk's avatar
wdenk committed
1310
    2	common/cmd_bootm.c	Image header has correct magic number
wdenk's avatar
wdenk committed
1311
   -2	common/cmd_bootm.c	Image header has bad	 checksum
wdenk's avatar
wdenk committed
1312
    3	common/cmd_bootm.c	Image header has correct checksum
wdenk's avatar
wdenk committed
1313
   -3	common/cmd_bootm.c	Image data   has bad	 checksum
wdenk's avatar
wdenk committed
1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325
    4	common/cmd_bootm.c	Image data   has correct checksum
   -4	common/cmd_bootm.c	Image is for unsupported architecture
    5	common/cmd_bootm.c	Architecture check OK
   -5	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
    6	common/cmd_bootm.c	Image Type check OK
   -6	common/cmd_bootm.c	gunzip uncompression error
   -7	common/cmd_bootm.c	Unimplemented compression type
    7	common/cmd_bootm.c	Uncompression OK
   -8	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
    8	common/cmd_bootm.c	Image Type check OK
   -9	common/cmd_bootm.c	Unsupported OS (not Linux, BSD, VxWorks, QNX)
    9	common/cmd_bootm.c	Start initial ramdisk verification
wdenk's avatar
wdenk committed
1326 1327
  -10	common/cmd_bootm.c	Ramdisk header has bad	   magic number
  -11	common/cmd_bootm.c	Ramdisk header has bad	   checksum
wdenk's avatar
wdenk committed
1328
   10	common/cmd_bootm.c	Ramdisk header is OK
wdenk's avatar
wdenk committed
1329
  -12	common/cmd_bootm.c	Ramdisk data   has bad	   checksum
wdenk's avatar
wdenk committed
1330 1331 1332 1333 1334 1335 1336
   11	common/cmd_bootm.c	Ramdisk data   has correct checksum
   12	common/cmd_bootm.c	Ramdisk verification complete, start loading
  -13	common/cmd_bootm.c	Wrong Image Type (not PPC Linux Ramdisk)
   13	common/cmd_bootm.c	Start multifile image verification
   14	common/cmd_bootm.c	No initial ramdisk, no multifile, continue.
   15	common/cmd_bootm.c	All preparation done, transferring control to OS

wdenk's avatar
wdenk committed
1337 1338 1339
  -30	lib_ppc/board.c		Fatal error, hang the system
  -31	post/post.c		POST test failed, detected by post_output_backlog()
  -32	post/post.c		POST test failed, detected by post_run_single()
1340

wdenk's avatar
wdenk committed
1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354
   -1	common/cmd_doc.c	Bad usage of "doc" command
   -1	common/cmd_doc.c	No boot device
   -1	common/cmd_doc.c	Unknown Chip ID on boot device
   -1	common/cmd_doc.c	Read Error on boot device
   -1	common/cmd_doc.c	Image header has bad magic number

   -1	common/cmd_ide.c	Bad usage of "ide" command
   -1	common/cmd_ide.c	No boot device
   -1	common/cmd_ide.c	Unknown boot device
   -1	common/cmd_ide.c	Unknown partition table
   -1	common/cmd_ide.c	Invalid partition type
   -1	common/cmd_ide.c	Read Error on boot device
   -1	common/cmd_ide.c	Image header has bad magic number

wdenk's avatar
wdenk committed
1355 1356 1357 1358 1359 1360
   -1	common/cmd_nand.c	Bad usage of "nand" command
   -1	common/cmd_nand.c	No boot device
   -1	common/cmd_nand.c	Unknown Chip ID on boot device
   -1	common/cmd_nand.c	Read Error on boot device
   -1	common/cmd_nand.c	Image header has bad magic number

wdenk's avatar
wdenk committed
1361
   -1	common/env_common.c	Environment has a bad CRC, using default
wdenk's avatar
wdenk committed
1362 1363 1364 1365 1366


Modem Support:
--------------

1367
[so far only for SMDK2400 and TRAB boards]
wdenk's avatar
wdenk committed
1368 1369 1370 1371 1372 1373 1374 1375 1376 1377

- Modem support endable:
		CONFIG_MODEM_SUPPORT

- RTS/CTS Flow control enable:
		CONFIG_HWFLOW

- Modem debug support:
		CONFIG_MODEM_SUPPORT_DEBUG

1378 1379
		Enables debugging stuff (char screen[1024], dbg())
		for modem support. Useful only with BDI2000.
wdenk's avatar
wdenk committed
1380

wdenk's avatar
wdenk committed
1381 1382
- Interrupt support (PPC):

wdenk's avatar
wdenk committed
1383 1384 1385 1386 1387 1388 1389 1390 1391 1392
		There are common interrupt_init() and timer_interrupt()
		for all PPC archs. interrupt_init() calls interrupt_init_cpu()
		for cpu specific initialization. interrupt_init_cpu()
		should set decrementer_count to appropriate value. If
		cpu resets decrementer automatically after interrupt
		(ppc4xx) it should set decrementer_count to zero.
		timer_interrupt() calls timer_interrupt_cpu() for cpu
		specific handling. If board has watchdog / status_led
		/ other_activity_monitor it works automatically from
		general timer_interrupt().
wdenk's avatar
wdenk committed
1393

wdenk's avatar
wdenk committed
1394 1395
- General:

1396 1397 1398 1399 1400 1401 1402
		In the target system modem support is enabled when a
		specific key (key combination) is pressed during
		power-on. Otherwise U-Boot will boot normally
		(autoboot). The key_pressed() fuction is called from
		board_init(). Currently key_pressed() is a dummy
		function, returning 1 and thus enabling modem
		initialization.
wdenk's avatar
wdenk committed
1403

1404 1405 1406 1407
		If there are no modem init strings in the
		environment, U-Boot proceed to autoboot; the
		previous output (banner, info printfs) will be
		supressed, though.
wdenk's avatar
wdenk committed
1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434

		See also: doc/README.Modem


Configuration Settings:
-----------------------

- CFG_LONGHELP: Defined when you want long help messages included;
		undefine this when you're short of memory.

- CFG_PROMPT:	This is what U-Boot prints on the console to
		prompt for user input.

- CFG_CBSIZE:	Buffer size for input from the Console

- CFG_PBSIZE:	Buffer size for Console output

- CFG_MAXARGS:	max. Number of arguments accepted for monitor commands

- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
		the application (usually a Linux kernel) when it is
		booted

- CFG_BAUDRATE_TABLE:
		List of legal baudrate settings for this board.

- CFG_CONSOLE_INFO_QUIET
wdenk's avatar
wdenk committed
1435
		Suppress display of console information at boot.
wdenk's avatar
wdenk committed
1436 1437

- CFG_CONSOLE_IS_IN_ENV
wdenk's avatar
wdenk committed
1438 1439 1440
		If the board specific function
			extern int overwrite_console (void);
		returns 1, the stdin, stderr and stdout are switched to the
wdenk's avatar
wdenk committed
1441 1442 1443
		serial port, else the settings in the environment are used.

- CFG_CONSOLE_OVERWRITE_ROUTINE
wdenk's avatar
wdenk committed
1444
		Enable the call to overwrite_console().
wdenk's avatar
wdenk committed
1445 1446 1447 1448 1449 1450 1451 1452 1453

- CFG_CONSOLE_ENV_OVERWRITE
		Enable overwrite of previous console environment settings.

- CFG_MEMTEST_START, CFG_MEMTEST_END:
		Begin and End addresses of the area used by the
		simple memory test.

- CFG_ALT_MEMTEST:
wdenk's avatar
wdenk committed
1454
		Enable an alternate, more extensive memory test.
wdenk's avatar
wdenk committed
1455

1456 1457 1458 1459
- CFG_MEMTEST_SCRATCH:
		Scratch address used by the alternate memory test
		You only need to set this if address zero isn't writeable

wdenk's avatar
wdenk committed
1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482
- CFG_TFTP_LOADADDR:
		Default load address for network file downloads

- CFG_LOADS_BAUD_CHANGE:
		Enable temporary baudrate change while serial download

- CFG_SDRAM_BASE:
		Physical start address of SDRAM. _Must_ be 0 here.

- CFG_MBIO_BASE:
		Physical start address of Motherboard I/O (if using a
		Cogent motherboard)

- CFG_FLASH_BASE:
		Physical start address of Flash memory.

- CFG_MONITOR_BASE:
		Physical start address of boot monitor code (set by
		make config files to be same as the text base address
		(TEXT_BASE) used when linking) - same as
		CFG_FLASH_BASE when booting from flash.

- CFG_MONITOR_LEN:
wdenk's avatar
wdenk committed
1483 1484 1485 1486
		Size of memory reserved for monitor code, used to
		determine _at_compile_time_ (!) if the environment is
		embedded within the U-Boot image, or in a separate
		flash sector.
wdenk's avatar
wdenk committed
1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508

- CFG_MALLOC_LEN:
		Size of DRAM reserved for malloc() use.

- CFG_BOOTMAPSZ:
		Maximum size of memory mapped by the startup code of
		the Linux kernel; all data that must be processed by
		the Linux kernel (bd_info, boot arguments, eventually
		initrd image) must be put below this limit.

- CFG_MAX_FLASH_BANKS:
		Max number of Flash memory banks

- CFG_MAX_FLASH_SECT:
		Max number of sectors on a Flash chip

- CFG_FLASH_ERASE_TOUT:
		Timeout for Flash erase operations (in ms)

- CFG_FLASH_WRITE_TOUT:
		Timeout for Flash write operations (in ms)

1509 1510 1511 1512 1513 1514 1515 1516 1517 1518
- CFG_FLASH_LOCK_TOUT
		Timeout for Flash set sector lock bit operation (in ms)

- CFG_FLASH_UNLOCK_TOUT
		Timeout for Flash clear lock bits operation (in ms)

- CFG_FLASH_PROTECTION
		If defined, hardware flash sectors protection is used
		instead of U-Boot software protection.

wdenk's avatar
wdenk committed
1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532
- CFG_DIRECT_FLASH_TFTP:

		Enable TFTP transfers directly to flash memory;
		without this option such a download has to be
		performed in two steps: (1) download to RAM, and (2)
		copy from RAM to flash.

		The two-step approach is usually more reliable, since
		you can check if the download worked before you erase
		the flash, but in some situations (when sytem RAM is
		too limited to allow for a tempory copy of the
		downloaded image) this option may be very useful.

- CFG_FLASH_CFI:
1533
		Define if the flash driver uses extra elements in the
wdenk's avatar
wdenk committed
1534 1535 1536 1537 1538
		common flash structure for storing flash geometry.

- CFG_FLASH_CFI_DRIVER
		This option also enables the building of the cfi_flash driver
		in the drivers directory
wdenk's avatar
wdenk committed
1539

stroese's avatar
stroese committed
1540 1541 1542 1543 1544 1545 1546 1547
- CFG_RX_ETH_BUFFER:
		Defines the number of ethernet receive buffers. On some
		ethernet controllers it is recommended to set this value
		to 8 or even higher (EEPRO100 or 405 EMAC), since all
		buffers can be full shortly after enabling the interface
		on high ethernet traffic.
		Defaults to 4 if not defined.

wdenk's avatar
wdenk committed
1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611
The following definitions that deal with the placement and management
of environment data (variable area); in general, we support the
following configurations:

- CFG_ENV_IS_IN_FLASH:

	Define this if the environment is in flash memory.

	a) The environment occupies one whole flash sector, which is
	   "embedded" in the text segment with the U-Boot code. This
	   happens usually with "bottom boot sector" or "top boot
	   sector" type flash chips, which have several smaller
	   sectors at the start or the end. For instance, such a
	   layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
	   such a case you would place the environment in one of the
	   4 kB sectors - with U-Boot code before and after it. With
	   "top boot sector" type flash chips, you would put the
	   environment in one of the last sectors, leaving a gap
	   between U-Boot and the environment.

	- CFG_ENV_OFFSET:

	   Offset of environment data (variable area) to the
	   beginning of flash memory; for instance, with bottom boot
	   type flash chips the second sector can be used: the offset
	   for this sector is given here.

	   CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.

	- CFG_ENV_ADDR:

	   This is just another way to specify the start address of
	   the flash sector containing the environment (instead of
	   CFG_ENV_OFFSET).

	- CFG_ENV_SECT_SIZE:

	   Size of the sector containing the environment.


	b) Sometimes flash chips have few, equal sized, BIG sectors.
	   In such a case you don't want to spend a whole sector for
	   the environment.

	- CFG_ENV_SIZE:

	   If you use this in combination with CFG_ENV_IS_IN_FLASH
	   and CFG_ENV_SECT_SIZE, you can specify to use only a part
	   of this flash sector for the environment. This saves
	   memory for the RAM copy of the environment.