xref: /openbmc/u-boot/README (revision 13a5695b7c454d5a2a5a885002cfe0e18536dad9)
1c609719bSwdenk#
23a473b2aSwdenk# (C) Copyright 2000 - 2004
3c609719bSwdenk# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4c609719bSwdenk#
5c609719bSwdenk# See file CREDITS for list of people who contributed to this
6c609719bSwdenk# project.
7c609719bSwdenk#
8c609719bSwdenk# This program is free software; you can redistribute it and/or
9c609719bSwdenk# modify it under the terms of the GNU General Public License as
10c609719bSwdenk# published by the Free Software Foundation; either version 2 of
11c609719bSwdenk# the License, or (at your option) any later version.
12c609719bSwdenk#
13c609719bSwdenk# This program is distributed in the hope that it will be useful,
14c609719bSwdenk# but WITHOUT ANY WARRANTY; without even the implied warranty of
15c609719bSwdenk# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
16c609719bSwdenk# GNU General Public License for more details.
17c609719bSwdenk#
18c609719bSwdenk# You should have received a copy of the GNU General Public License
19c609719bSwdenk# along with this program; if not, write to the Free Software
20c609719bSwdenk# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21c609719bSwdenk# MA 02111-1307 USA
22c609719bSwdenk#
23c609719bSwdenk
24c609719bSwdenkSummary:
25c609719bSwdenk========
26c609719bSwdenk
2724ee89b9SwdenkThis directory contains the source code for U-Boot, a boot loader for
2824ee89b9SwdenkEmbedded boards based on PowerPC and ARM processors, which can be
2924ee89b9Swdenkinstalled in a boot ROM and used to initialize and test the hardware
3024ee89b9Swdenkor to download and run application code.
31c609719bSwdenk
32c609719bSwdenkThe development of U-Boot is closely related to Linux: some parts of
3324ee89b9Swdenkthe source code originate in the Linux source tree, we have some
3424ee89b9Swdenkheader files in common, and special provision has been made to
35c609719bSwdenksupport booting of Linux images.
36c609719bSwdenk
37c609719bSwdenkSome attention has been paid to make this software easily
38c609719bSwdenkconfigurable and extendable. For instance, all monitor commands are
39c609719bSwdenkimplemented with the same call interface, so that it's very easy to
40c609719bSwdenkadd new commands. Also, instead of permanently adding rarely used
41c609719bSwdenkcode (for instance hardware test utilities) to the monitor, you can
42c609719bSwdenkload and run it dynamically.
43c609719bSwdenk
44c609719bSwdenk
45c609719bSwdenkStatus:
46c609719bSwdenk=======
47c609719bSwdenk
48c609719bSwdenkIn general, all boards for which a configuration option exists in the
49c609719bSwdenkMakefile have been tested to some extent and can be considered
50c609719bSwdenk"working". In fact, many of them are used in production systems.
51c609719bSwdenk
52c609719bSwdenkIn case of problems see the CHANGELOG and CREDITS files to find out
53c609719bSwdenkwho contributed the specific port.
54c609719bSwdenk
55c609719bSwdenk
56c609719bSwdenkWhere to get help:
57c609719bSwdenk==================
58c609719bSwdenk
59c609719bSwdenkIn case you have questions about, problems with or contributions for
60c609719bSwdenkU-Boot you should send a message to the U-Boot mailing list at
61c609719bSwdenk<u-boot-users@lists.sourceforge.net>. There is also an archive of
62c609719bSwdenkprevious traffic on the mailing list - please search the archive
63c609719bSwdenkbefore asking FAQ's. Please see
64c609719bSwdenkhttp://lists.sourceforge.net/lists/listinfo/u-boot-users/
65c609719bSwdenk
66c609719bSwdenk
67c609719bSwdenkWhere we come from:
68c609719bSwdenk===================
69c609719bSwdenk
70c609719bSwdenk- start from 8xxrom sources
7124ee89b9Swdenk- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
72c609719bSwdenk- clean up code
73c609719bSwdenk- make it easier to add custom boards
74c609719bSwdenk- make it possible to add other [PowerPC] CPUs
75c609719bSwdenk- extend functions, especially:
76c609719bSwdenk  * Provide extended interface to Linux boot loader
77c609719bSwdenk  * S-Record download
78c609719bSwdenk  * network boot
79c609719bSwdenk  * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
8024ee89b9Swdenk- create ARMBoot project (http://sourceforge.net/projects/armboot)
81c609719bSwdenk- add other CPU families (starting with ARM)
8224ee89b9Swdenk- create U-Boot project (http://sourceforge.net/projects/u-boot)
8324ee89b9Swdenk
8424ee89b9Swdenk
8524ee89b9SwdenkNames and Spelling:
8624ee89b9Swdenk===================
8724ee89b9Swdenk
8824ee89b9SwdenkThe "official" name of this project is "Das U-Boot". The spelling
8924ee89b9Swdenk"U-Boot" shall be used in all written text (documentation, comments
9024ee89b9Swdenkin source files etc.). Example:
9124ee89b9Swdenk
9224ee89b9Swdenk	This is the README file for the U-Boot project.
9324ee89b9Swdenk
9424ee89b9SwdenkFile names etc. shall be based on the string "u-boot". Examples:
9524ee89b9Swdenk
9624ee89b9Swdenk	include/asm-ppc/u-boot.h
9724ee89b9Swdenk
9824ee89b9Swdenk	#include <asm/u-boot.h>
9924ee89b9Swdenk
10024ee89b9SwdenkVariable names, preprocessor constants etc. shall be either based on
10124ee89b9Swdenkthe string "u_boot" or on "U_BOOT". Example:
10224ee89b9Swdenk
10324ee89b9Swdenk	U_BOOT_VERSION		u_boot_logo
10424ee89b9Swdenk	IH_OS_U_BOOT		u_boot_hush_start
105c609719bSwdenk
106c609719bSwdenk
10793f19cc0SwdenkVersioning:
10893f19cc0Swdenk===========
10993f19cc0Swdenk
11093f19cc0SwdenkU-Boot uses a 3 level version number containing a version, a
11193f19cc0Swdenksub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
11293f19cc0Swdenksub-version "34", and patchlevel "4".
11393f19cc0Swdenk
11493f19cc0SwdenkThe patchlevel is used to indicate certain stages of development
11593f19cc0Swdenkbetween released versions, i. e. officially released versions of
11693f19cc0SwdenkU-Boot will always have a patchlevel of "0".
11793f19cc0Swdenk
11893f19cc0Swdenk
119c609719bSwdenkDirectory Hierarchy:
120c609719bSwdenk====================
121c609719bSwdenk
1227152b1d0Swdenk- board		Board dependent files
1237152b1d0Swdenk- common	Misc architecture independent functions
124c609719bSwdenk- cpu		CPU specific files
12511dadd54Swdenk  - 74xx_7xx	Files specific to Motorola MPC74xx and 7xx CPUs
12611dadd54Swdenk  - arm720t	Files specific to ARM 720 CPUs
12711dadd54Swdenk  - arm920t	Files specific to ARM 920 CPUs
12811dadd54Swdenk  - arm925t	Files specific to ARM 925 CPUs
12911dadd54Swdenk  - arm926ejs	Files specific to ARM 926 CPUs
13011dadd54Swdenk  - at91rm9200	Files specific to Atmel AT91RM9200 CPUs
13111dadd54Swdenk  - i386	Files specific to i386 CPUs
13211dadd54Swdenk  - ixp		Files specific to Intel XScale IXP CPUs
13311dadd54Swdenk  - mcf52x2	Files specific to Motorola ColdFire MCF52x2 CPUs
13411dadd54Swdenk  - mips	Files specific to MIPS CPUs
13511dadd54Swdenk  - mpc5xx	Files specific to Motorola MPC5xx  CPUs
13611dadd54Swdenk  - mpc5xxx	Files specific to Motorola MPC5xxx CPUs
13711dadd54Swdenk  - mpc8xx	Files specific to Motorola MPC8xx  CPUs
13811dadd54Swdenk  - mpc824x	Files specific to Motorola MPC824x CPUs
13911dadd54Swdenk  - mpc8260	Files specific to Motorola MPC8260 CPUs
14011dadd54Swdenk  - mpc85xx	Files specific to Motorola MPC85xx CPUs
14111dadd54Swdenk  - nios	Files specific to Altera NIOS CPUs
14211dadd54Swdenk  - ppc4xx	Files specific to IBM PowerPC 4xx CPUs
14311dadd54Swdenk  - pxa		Files specific to Intel XScale PXA CPUs
14411dadd54Swdenk  - s3c44b0	Files specific to Samsung S3C44B0 CPUs
14511dadd54Swdenk  - sa1100	Files specific to Intel StrongARM SA1100 CPUs
146c609719bSwdenk- disk		Code for disk drive partition handling
147c609719bSwdenk- doc		Documentation (don't expect too much)
1487152b1d0Swdenk- drivers	Commonly used device drivers
149c609719bSwdenk- dtt		Digital Thermometer and Thermostat drivers
150c609719bSwdenk- examples	Example code for standalone applications, etc.
151c609719bSwdenk- include	Header Files
15211dadd54Swdenk- lib_arm	Files generic to ARM	 architecture
15311dadd54Swdenk- lib_generic	Files generic to all	 architectures
15411dadd54Swdenk- lib_i386	Files generic to i386	 architecture
15511dadd54Swdenk- lib_m68k	Files generic to m68k	 architecture
15611dadd54Swdenk- lib_mips	Files generic to MIPS	 architecture
15711dadd54Swdenk- lib_nios	Files generic to NIOS	 architecture
15811dadd54Swdenk- lib_ppc	Files generic to PowerPC architecture
159c609719bSwdenk- net		Networking code
160c609719bSwdenk- post		Power On Self Test
161c609719bSwdenk- rtc		Real Time Clock drivers
162c609719bSwdenk- tools		Tools to build S-Record or U-Boot images, etc.
163c609719bSwdenk
164c609719bSwdenkSoftware Configuration:
165c609719bSwdenk=======================
166c609719bSwdenk
167c609719bSwdenkConfiguration is usually done using C preprocessor defines; the
168c609719bSwdenkrationale behind that is to avoid dead code whenever possible.
169c609719bSwdenk
170c609719bSwdenkThere are two classes of configuration variables:
171c609719bSwdenk
172c609719bSwdenk* Configuration _OPTIONS_:
173c609719bSwdenk  These are selectable by the user and have names beginning with
174c609719bSwdenk  "CONFIG_".
175c609719bSwdenk
176c609719bSwdenk* Configuration _SETTINGS_:
177c609719bSwdenk  These depend on the hardware etc. and should not be meddled with if
178c609719bSwdenk  you don't know what you're doing; they have names beginning with
179c609719bSwdenk  "CFG_".
180c609719bSwdenk
181c609719bSwdenkLater we will add a configuration tool - probably similar to or even
182c609719bSwdenkidentical to what's used for the Linux kernel. Right now, we have to
183c609719bSwdenkdo the configuration by hand, which means creating some symbolic
184c609719bSwdenklinks and editing some configuration files. We use the TQM8xxL boards
185c609719bSwdenkas an example here.
186c609719bSwdenk
187c609719bSwdenk
188c609719bSwdenkSelection of Processor Architecture and Board Type:
189c609719bSwdenk---------------------------------------------------
190c609719bSwdenk
191c609719bSwdenkFor all supported boards there are ready-to-use default
192c609719bSwdenkconfigurations available; just type "make <board_name>_config".
193c609719bSwdenk
194c609719bSwdenkExample: For a TQM823L module type:
195c609719bSwdenk
196c609719bSwdenk	cd u-boot
197c609719bSwdenk	make TQM823L_config
198c609719bSwdenk
199c609719bSwdenkFor the Cogent platform, you need to specify the cpu type as well;
200c609719bSwdenke.g. "make cogent_mpc8xx_config". And also configure the cogent
201c609719bSwdenkdirectory according to the instructions in cogent/README.
202c609719bSwdenk
203c609719bSwdenk
204c609719bSwdenkConfiguration Options:
205c609719bSwdenk----------------------
206c609719bSwdenk
207c609719bSwdenkConfiguration depends on the combination of board and CPU type; all
208c609719bSwdenksuch information is kept in a configuration file
209c609719bSwdenk"include/configs/<board_name>.h".
210c609719bSwdenk
211c609719bSwdenkExample: For a TQM823L module, all configuration settings are in
212c609719bSwdenk"include/configs/TQM823L.h".
213c609719bSwdenk
214c609719bSwdenk
2157f6c2cbcSwdenkMany of the options are named exactly as the corresponding Linux
2167f6c2cbcSwdenkkernel configuration options. The intention is to make it easier to
2177f6c2cbcSwdenkbuild a config tool - later.
2187f6c2cbcSwdenk
2197f6c2cbcSwdenk
220c609719bSwdenkThe following options need to be configured:
221c609719bSwdenk
222c609719bSwdenk- CPU Type:	Define exactly one of
223c609719bSwdenk
224c609719bSwdenk		PowerPC based CPUs:
225c609719bSwdenk		-------------------
226c609719bSwdenk		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860
2270db5bca8Swdenk	or	CONFIG_MPC5xx
228c609719bSwdenk	or	CONFIG_MPC824X, CONFIG_MPC8260
22942d1f039Swdenk	or	CONFIG_MPC85xx
230c609719bSwdenk	or	CONFIG_IOP480
231c609719bSwdenk	or	CONFIG_405GP
23212f34241Swdenk	or	CONFIG_405EP
233c609719bSwdenk	or	CONFIG_440
234c609719bSwdenk	or	CONFIG_MPC74xx
23572755c71Swdenk	or	CONFIG_750FX
236c609719bSwdenk
237c609719bSwdenk		ARM based CPUs:
238c609719bSwdenk		---------------
239c609719bSwdenk		CONFIG_SA1110
240c609719bSwdenk		CONFIG_ARM7
241c609719bSwdenk		CONFIG_PXA250
242c609719bSwdenk
243507bbe3eSwdenk		MicroBlaze based CPUs:
244507bbe3eSwdenk		----------------------
245507bbe3eSwdenk		CONFIG_MICROBLZE
246507bbe3eSwdenk
247c609719bSwdenk
248c609719bSwdenk- Board Type:	Define exactly one of
249c609719bSwdenk
250c609719bSwdenk		PowerPC based boards:
251c609719bSwdenk		---------------------
252c609719bSwdenk
25317ea1177Swdenk		CONFIG_ADCIOP		CONFIG_GEN860T		CONFIG_PCI405
25417ea1177Swdenk		CONFIG_ADS860		CONFIG_GENIETV		CONFIG_PCIPPC2
25517ea1177Swdenk		CONFIG_AMX860		CONFIG_GTH		CONFIG_PCIPPC6
25617ea1177Swdenk		CONFIG_AR405		CONFIG_gw8260		CONFIG_pcu_e
25717ea1177Swdenk		CONFIG_BAB7xx		CONFIG_hermes		CONFIG_PIP405
25817ea1177Swdenk		CONFIG_c2mon		CONFIG_hymod		CONFIG_PM826
25917ea1177Swdenk		CONFIG_CANBT		CONFIG_IAD210		CONFIG_ppmc8260
26017ea1177Swdenk		CONFIG_CCM		CONFIG_ICU862		CONFIG_QS823
26117ea1177Swdenk		CONFIG_CMI		CONFIG_IP860		CONFIG_QS850
26217ea1177Swdenk		CONFIG_cogent_mpc8260	CONFIG_IPHASE4539	CONFIG_QS860T
26317ea1177Swdenk		CONFIG_cogent_mpc8xx	CONFIG_IVML24		CONFIG_RBC823
26417ea1177Swdenk		CONFIG_CPCI405		CONFIG_IVML24_128	CONFIG_RPXClassic
26517ea1177Swdenk		CONFIG_CPCI4052		CONFIG_IVML24_256	CONFIG_RPXlite
26617ea1177Swdenk		CONFIG_CPCIISER4	CONFIG_IVMS8		CONFIG_RPXsuper
26717ea1177Swdenk		CONFIG_CPU86		CONFIG_IVMS8_128	CONFIG_rsdproto
26817ea1177Swdenk		CONFIG_CRAYL1		CONFIG_IVMS8_256	CONFIG_sacsng
26917ea1177Swdenk		CONFIG_CSB272		CONFIG_JSE		CONFIG_Sandpoint8240
27017ea1177Swdenk		CONFIG_CU824		CONFIG_LANTEC		CONFIG_Sandpoint8245
27117ea1177Swdenk		CONFIG_DASA_SIM		CONFIG_lwmon		CONFIG_sbc8260
27217ea1177Swdenk		CONFIG_DB64360		CONFIG_MBX		CONFIG_SM850
27317ea1177Swdenk		CONFIG_DB64460		CONFIG_MBX860T		CONFIG_SPD823TS
27417ea1177Swdenk		CONFIG_DU405		CONFIG_MHPC		CONFIG_STXGP3
27517ea1177Swdenk		CONFIG_DUET_ADS		CONFIG_MIP405		CONFIG_SXNI855T
27617ea1177Swdenk		CONFIG_EBONY		CONFIG_MOUSSE		CONFIG_TQM823L
27717ea1177Swdenk		CONFIG_ELPPC		CONFIG_MPC8260ADS	CONFIG_TQM8260
27817ea1177Swdenk		CONFIG_ELPT860		CONFIG_MPC8540ADS	CONFIG_TQM850L
27917ea1177Swdenk		CONFIG_ep8260		CONFIG_MPC8560ADS	CONFIG_TQM855L
28017ea1177Swdenk		CONFIG_ERIC		CONFIG_MUSENKI		CONFIG_TQM860L
28117ea1177Swdenk		CONFIG_ESTEEM192E	CONFIG_MVS1		CONFIG_TTTech
28217ea1177Swdenk		CONFIG_ETX094		CONFIG_NETPHONE		CONFIG_UTX8245
28317ea1177Swdenk		CONFIG_EVB64260		CONFIG_NETTA		CONFIG_V37
28417ea1177Swdenk		CONFIG_FADS823		CONFIG_NETVIA		CONFIG_W7OLMC
28517ea1177Swdenk		CONFIG_FADS850SAR	CONFIG_NX823		CONFIG_W7OLMG
28617ea1177Swdenk		CONFIG_FADS860T		CONFIG_OCRTC		CONFIG_WALNUT405
28717ea1177Swdenk		CONFIG_FLAGADM		CONFIG_ORSG		CONFIG_ZPC1900
28817ea1177Swdenk		CONFIG_FPS850L		CONFIG_OXC		CONFIG_ZUMA
28917ea1177Swdenk		CONFIG_FPS860L
290c609719bSwdenk
291c609719bSwdenk		ARM based boards:
292c609719bSwdenk		-----------------
293c609719bSwdenk
294db01a2eaSwdenk		CONFIG_AT91RM9200DK,		CONFIG_DNP1110,		CONFIG_EP7312,
295db01a2eaSwdenk		CONFIG_H2_OMAP1610,		CONFIG_HHP_CRADLE,	CONFIG_IMPA7,
296db01a2eaSwdenk		CONFIG_INNOVATOROMAP1510,   CONFIG_INNOVATOROMAP1610,	CONFIG_LART,
297f39748aeSwdenk		CONFIG_LPD7A400			CONFIG_LUBBOCK,		CONFIG_OSK_OMAP5912,
298f39748aeSwdenk		CONFIG_SHANNON,			CONFIG_P2_OMAP730,	CONFIG_SMDK2400,
299f39748aeSwdenk		CONFIG_SMDK2410,		CONFIG_TRAB,		CONFIG_VCMA9
300c609719bSwdenk
301507bbe3eSwdenk		MicroBlaze based boards:
302507bbe3eSwdenk		------------------------
303507bbe3eSwdenk
304507bbe3eSwdenk		CONFIG_SUZAKU
305507bbe3eSwdenk
306c609719bSwdenk
307c609719bSwdenk- CPU Module Type: (if CONFIG_COGENT is defined)
308c609719bSwdenk		Define exactly one of
309c609719bSwdenk		CONFIG_CMA286_60_OLD
310c609719bSwdenk--- FIXME --- not tested yet:
311c609719bSwdenk		CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
312c609719bSwdenk		CONFIG_CMA287_23, CONFIG_CMA287_50
313c609719bSwdenk
314c609719bSwdenk- Motherboard Type: (if CONFIG_COGENT is defined)
315c609719bSwdenk		Define exactly one of
316c609719bSwdenk		CONFIG_CMA101, CONFIG_CMA102
317c609719bSwdenk
318c609719bSwdenk- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
319c609719bSwdenk		Define one or more of
320c609719bSwdenk		CONFIG_CMA302
321c609719bSwdenk
322c609719bSwdenk- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
323c609719bSwdenk		Define one or more of
324c609719bSwdenk		CONFIG_LCD_HEARTBEAT	- update a character position on
325c609719bSwdenk					  the lcd display every second with
326c609719bSwdenk					  a "rotator" |\-/|\-/
327c609719bSwdenk
3282535d602Swdenk- Board flavour: (if CONFIG_MPC8260ADS is defined)
3292535d602Swdenk		CONFIG_ADSTYPE
3302535d602Swdenk		Possible values are:
3312535d602Swdenk			CFG_8260ADS	- original MPC8260ADS
332180d3f74Swdenk			CFG_8266ADS	- MPC8266ADS
33354387ac9Swdenk			CFG_PQ2FADS	- PQ2FADS-ZU or PQ2FADS-VR
33404a85b3bSwdenk			CFG_8272ADS	- MPC8272ADS
3352535d602Swdenk
336c609719bSwdenk- MPC824X Family Member (if CONFIG_MPC824X is defined)
337c609719bSwdenk		Define exactly one of
338c609719bSwdenk		CONFIG_MPC8240, CONFIG_MPC8245
339c609719bSwdenk
34075d1ea7fSwdenk- 8xx CPU Options: (if using an MPC8xx cpu)
341c609719bSwdenk		Define one or more of
3425da627a4Swdenk		CONFIG_8xx_GCLK_FREQ	- if get_gclk_freq() cannot work
3435da627a4Swdenk					  e.g. if there is no 32KHz
3445da627a4Swdenk					  reference PIT/RTC clock
345c609719bSwdenk
34675d1ea7fSwdenk- 859/866 CPU options: (if using a MPC859 or MPC866 CPU):
34775d1ea7fSwdenk		CFG_866_OSCCLK
34875d1ea7fSwdenk		CFG_866_CPUCLK_MIN
34975d1ea7fSwdenk		CFG_866_CPUCLK_MAX
35075d1ea7fSwdenk		CFG_866_CPUCLK_DEFAULT
35175d1ea7fSwdenk			See doc/README.MPC866
35275d1ea7fSwdenk
35375d1ea7fSwdenk		CFG_MEASURE_CPUCLK
35475d1ea7fSwdenk
35575d1ea7fSwdenk		Define this to measure the actual CPU clock instead
35675d1ea7fSwdenk		of relying on the correctness of the configured
35775d1ea7fSwdenk		values. Mostly useful for board bringup to make sure
35875d1ea7fSwdenk		the PLL is locked at the intended frequency. Note
35975d1ea7fSwdenk		that this requires a (stable) reference clock (32 kHz
36075d1ea7fSwdenk		RTC clock),
36175d1ea7fSwdenk
3625da627a4Swdenk- Linux Kernel Interface:
363c609719bSwdenk		CONFIG_CLOCKS_IN_MHZ
364c609719bSwdenk
365c609719bSwdenk		U-Boot stores all clock information in Hz
366c609719bSwdenk		internally. For binary compatibility with older Linux
367c609719bSwdenk		kernels (which expect the clocks passed in the
368c609719bSwdenk		bd_info data to be in MHz) the environment variable
369c609719bSwdenk		"clocks_in_mhz" can be defined so that U-Boot
370c609719bSwdenk		converts clock data to MHZ before passing it to the
371c609719bSwdenk		Linux kernel.
372c609719bSwdenk		When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
373c609719bSwdenk		"clocks_in_mhz=1" is  automatically  included  in  the
374c609719bSwdenk		default environment.
375c609719bSwdenk
3765da627a4Swdenk		CONFIG_MEMSIZE_IN_BYTES		[relevant for MIPS only]
3775da627a4Swdenk
3785da627a4Swdenk		When transfering memsize parameter to linux, some versions
3795da627a4Swdenk		expect it to be in bytes, others in MB.
3805da627a4Swdenk		Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
3815da627a4Swdenk
382c609719bSwdenk- Console Interface:
383c609719bSwdenk		Depending on board, define exactly one serial port
384c609719bSwdenk		(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
385c609719bSwdenk		CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
386c609719bSwdenk		console by defining CONFIG_8xx_CONS_NONE
387c609719bSwdenk
388c609719bSwdenk		Note: if CONFIG_8xx_CONS_NONE is defined, the serial
389c609719bSwdenk		port routines must be defined elsewhere
390c609719bSwdenk		(i.e. serial_init(), serial_getc(), ...)
391c609719bSwdenk
392c609719bSwdenk		CONFIG_CFB_CONSOLE
393c609719bSwdenk		Enables console device for a color framebuffer. Needs following
394c609719bSwdenk		defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
395c609719bSwdenk			VIDEO_FB_LITTLE_ENDIAN	graphic memory organisation
396c609719bSwdenk						(default big endian)
397c609719bSwdenk			VIDEO_HW_RECTFILL	graphic chip supports
398c609719bSwdenk						rectangle fill
399c609719bSwdenk						(cf. smiLynxEM)
400c609719bSwdenk			VIDEO_HW_BITBLT		graphic chip supports
401c609719bSwdenk						bit-blit (cf. smiLynxEM)
402c609719bSwdenk			VIDEO_VISIBLE_COLS	visible pixel columns
403c609719bSwdenk						(cols=pitch)
404c609719bSwdenk			VIDEO_VISIBLE_ROWS	visible pixel rows
405c609719bSwdenk			VIDEO_PIXEL_SIZE	bytes per pixel
406c609719bSwdenk			VIDEO_DATA_FORMAT	graphic data format
407c609719bSwdenk						(0-5, cf. cfb_console.c)
408c609719bSwdenk			VIDEO_FB_ADRS		framebuffer address
409c609719bSwdenk			VIDEO_KBD_INIT_FCT	keyboard int fct
410c609719bSwdenk						(i.e. i8042_kbd_init())
411c609719bSwdenk			VIDEO_TSTC_FCT		test char fct
412c609719bSwdenk						(i.e. i8042_tstc)
413c609719bSwdenk			VIDEO_GETC_FCT		get char fct
414c609719bSwdenk						(i.e. i8042_getc)
415c609719bSwdenk			CONFIG_CONSOLE_CURSOR	cursor drawing on/off
416c609719bSwdenk						(requires blink timer
417c609719bSwdenk						cf. i8042.c)
418c609719bSwdenk			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
419c609719bSwdenk			CONFIG_CONSOLE_TIME	display time/date info in
420c609719bSwdenk						upper right corner
421c609719bSwdenk						(requires CFG_CMD_DATE)
422c609719bSwdenk			CONFIG_VIDEO_LOGO	display Linux logo in
423c609719bSwdenk						upper left corner
424a6c7ad2fSwdenk			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of
425a6c7ad2fSwdenk						linux_logo.h for logo.
426a6c7ad2fSwdenk						Requires CONFIG_VIDEO_LOGO
427c609719bSwdenk			CONFIG_CONSOLE_EXTRA_INFO
428c609719bSwdenk						addional board info beside
429c609719bSwdenk						the logo
430c609719bSwdenk
431c609719bSwdenk		When CONFIG_CFB_CONSOLE is defined, video console is
432c609719bSwdenk		default i/o. Serial console can be forced with
433c609719bSwdenk		environment 'console=serial'.
434c609719bSwdenk
435a3ad8e26Swdenk		When CONFIG_SILENT_CONSOLE is defined, all console
436a3ad8e26Swdenk		messages (by U-Boot and Linux!) can be silenced with
437a3ad8e26Swdenk		the "silent" environment variable. See
438a3ad8e26Swdenk		doc/README.silent for more information.
439a3ad8e26Swdenk
440c609719bSwdenk- Console Baudrate:
441c609719bSwdenk		CONFIG_BAUDRATE - in bps
442c609719bSwdenk		Select one of the baudrates listed in
443c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
4443bbc899fSwdenk		CFG_BRGCLK_PRESCALE, baudrate prescale
445c609719bSwdenk
446c609719bSwdenk- Interrupt driven serial port input:
447c609719bSwdenk		CONFIG_SERIAL_SOFTWARE_FIFO
448c609719bSwdenk
449c609719bSwdenk		PPC405GP only.
450c609719bSwdenk		Use an interrupt handler for receiving data on the
451c609719bSwdenk		serial port. It also enables using hardware handshake
452c609719bSwdenk		(RTS/CTS) and UART's built-in FIFO. Set the number of
453c609719bSwdenk		bytes the interrupt driven input buffer should have.
454c609719bSwdenk
455109c0e3aSwdenk		Leave undefined to disable this feature, including
456109c0e3aSwdenk		disable the buffer and hardware handshake.
457c609719bSwdenk
4581d49b1f3Sstroese- Console UART Number:
4591d49b1f3Sstroese		CONFIG_UART1_CONSOLE
4601d49b1f3Sstroese
4611d49b1f3Sstroese		IBM PPC4xx only.
4621d49b1f3Sstroese		If defined internal UART1 (and not UART0) is used
4631d49b1f3Sstroese		as default U-Boot console.
4641d49b1f3Sstroese
465c609719bSwdenk- Boot Delay:	CONFIG_BOOTDELAY - in seconds
466c609719bSwdenk		Delay before automatically booting the default image;
467c609719bSwdenk		set to -1 to disable autoboot.
468c609719bSwdenk
469c609719bSwdenk		See doc/README.autoboot for these options that
470c609719bSwdenk		work with CONFIG_BOOTDELAY. None are required.
471c609719bSwdenk		CONFIG_BOOT_RETRY_TIME
472c609719bSwdenk		CONFIG_BOOT_RETRY_MIN
473c609719bSwdenk		CONFIG_AUTOBOOT_KEYED
474c609719bSwdenk		CONFIG_AUTOBOOT_PROMPT
475c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR
476c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR
477c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR2
478c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR2
479c609719bSwdenk		CONFIG_ZERO_BOOTDELAY_CHECK
480c609719bSwdenk		CONFIG_RESET_TO_RETRY
481c609719bSwdenk
482c609719bSwdenk- Autoboot Command:
483c609719bSwdenk		CONFIG_BOOTCOMMAND
484c609719bSwdenk		Only needed when CONFIG_BOOTDELAY is enabled;
485c609719bSwdenk		define a command string that is automatically executed
486c609719bSwdenk		when no character is read on the console interface
487c609719bSwdenk		within "Boot Delay" after reset.
488c609719bSwdenk
489c609719bSwdenk		CONFIG_BOOTARGS
490c609719bSwdenk		This can be used to pass arguments to the bootm
491c609719bSwdenk		command. The value of CONFIG_BOOTARGS goes into the
492c609719bSwdenk		environment value "bootargs".
493c609719bSwdenk
494c609719bSwdenk		CONFIG_RAMBOOT and CONFIG_NFSBOOT
495c609719bSwdenk		The value of these goes into the environment as
496c609719bSwdenk		"ramboot" and "nfsboot" respectively, and can be used
497c609719bSwdenk		as a convenience, when switching between booting from
498c609719bSwdenk		ram and nfs.
499c609719bSwdenk
500c609719bSwdenk- Pre-Boot Commands:
501c609719bSwdenk		CONFIG_PREBOOT
502c609719bSwdenk
503c609719bSwdenk		When this option is #defined, the existence of the
504c609719bSwdenk		environment variable "preboot" will be checked
505c609719bSwdenk		immediately before starting the CONFIG_BOOTDELAY
506c609719bSwdenk		countdown and/or running the auto-boot command resp.
507c609719bSwdenk		entering interactive mode.
508c609719bSwdenk
509c609719bSwdenk		This feature is especially useful when "preboot" is
510c609719bSwdenk		automatically generated or modified. For an example
511c609719bSwdenk		see the LWMON board specific code: here "preboot" is
512c609719bSwdenk		modified when the user holds down a certain
513c609719bSwdenk		combination of keys on the (special) keyboard when
514c609719bSwdenk		booting the systems
515c609719bSwdenk
516c609719bSwdenk- Serial Download Echo Mode:
517c609719bSwdenk		CONFIG_LOADS_ECHO
518c609719bSwdenk		If defined to 1, all characters received during a
519c609719bSwdenk		serial download (using the "loads" command) are
520c609719bSwdenk		echoed back. This might be needed by some terminal
521c609719bSwdenk		emulations (like "cu"), but may as well just take
522c609719bSwdenk		time on others. This setting #define's the initial
523c609719bSwdenk		value of the "loads_echo" environment variable.
524c609719bSwdenk
525c609719bSwdenk- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
526c609719bSwdenk		CONFIG_KGDB_BAUDRATE
527c609719bSwdenk		Select one of the baudrates listed in
528c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
529c609719bSwdenk
530c609719bSwdenk- Monitor Functions:
531c609719bSwdenk		CONFIG_COMMANDS
532c609719bSwdenk		Most monitor functions can be selected (or
533c609719bSwdenk		de-selected) by adjusting the definition of
534c609719bSwdenk		CONFIG_COMMANDS; to select individual functions,
535c609719bSwdenk		#define CONFIG_COMMANDS by "OR"ing any of the
536c609719bSwdenk		following values:
537c609719bSwdenk
538c609719bSwdenk		#define enables commands:
539c609719bSwdenk		-------------------------
540c609719bSwdenk		CFG_CMD_ASKENV	* ask for env variable
54178137c3cSwdenk		CFG_CMD_AUTOSCRIPT Autoscript Support
542c609719bSwdenk		CFG_CMD_BDI	  bdinfo
543c609719bSwdenk		CFG_CMD_BEDBUG	  Include BedBug Debugger
54478137c3cSwdenk		CFG_CMD_BMP	* BMP support
545c609719bSwdenk		CFG_CMD_BOOTD	  bootd
546c609719bSwdenk		CFG_CMD_CACHE	  icache, dcache
547c609719bSwdenk		CFG_CMD_CONSOLE	  coninfo
548c609719bSwdenk		CFG_CMD_DATE	* support for RTC, date/time...
549c609719bSwdenk		CFG_CMD_DHCP	  DHCP support
55078137c3cSwdenk		CFG_CMD_DIAG	* Diagnostics
55178137c3cSwdenk		CFG_CMD_DOC	* Disk-On-Chip Support
55278137c3cSwdenk		CFG_CMD_DTT	  Digital Therm and Thermostat
553c609719bSwdenk		CFG_CMD_ECHO	* echo arguments
554c609719bSwdenk		CFG_CMD_EEPROM	* EEPROM read/write support
555c609719bSwdenk		CFG_CMD_ELF	  bootelf, bootvx
556c609719bSwdenk		CFG_CMD_ENV	  saveenv
557c609719bSwdenk		CFG_CMD_FDC	* Floppy Disk Support
55871f95118Swdenk		CFG_CMD_FAT	  FAT partition support
5592262cfeeSwdenk		CFG_CMD_FDOS	* Dos diskette Support
560c609719bSwdenk		CFG_CMD_FLASH	  flinfo, erase, protect
561c609719bSwdenk		CFG_CMD_FPGA	  FPGA device initialization support
56278137c3cSwdenk		CFG_CMD_HWFLOW	* RTS/CTS hw flow control
563c609719bSwdenk		CFG_CMD_I2C	* I2C serial bus support
564c609719bSwdenk		CFG_CMD_IDE	* IDE harddisk support
565c609719bSwdenk		CFG_CMD_IMI	  iminfo
56678137c3cSwdenk		CFG_CMD_IMLS	  List all found images
567c609719bSwdenk		CFG_CMD_IMMAP	* IMMR dump support
568c609719bSwdenk		CFG_CMD_IRQ	* irqinfo
5692d1a537dSwdenk		CFG_CMD_ITEST	* Integer/string test of 2 values
57078137c3cSwdenk		CFG_CMD_JFFS2	* JFFS2 Support
571c609719bSwdenk		CFG_CMD_KGDB	* kgdb
572c609719bSwdenk		CFG_CMD_LOADB	  loadb
573c609719bSwdenk		CFG_CMD_LOADS	  loads
574c609719bSwdenk		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
575c609719bSwdenk				  loop, mtest
57678137c3cSwdenk		CFG_CMD_MISC	  Misc functions like sleep etc
57771f95118Swdenk		CFG_CMD_MMC	  MMC memory mapped support
578c609719bSwdenk		CFG_CMD_MII	  MII utility commands
57978137c3cSwdenk		CFG_CMD_NAND	* NAND support
580c609719bSwdenk		CFG_CMD_NET	  bootp, tftpboot, rarpboot
581c609719bSwdenk		CFG_CMD_PCI	* pciinfo
582c609719bSwdenk		CFG_CMD_PCMCIA	* PCMCIA support
58378137c3cSwdenk		CFG_CMD_PING	* send ICMP ECHO_REQUEST to network host
584ef5a9672Swdenk		CFG_CMD_PORTIO	* Port I/O
585c609719bSwdenk		CFG_CMD_REGINFO * Register dump
586c609719bSwdenk		CFG_CMD_RUN	  run command in env variable
58778137c3cSwdenk		CFG_CMD_SAVES	  save S record dump
588c609719bSwdenk		CFG_CMD_SCSI	* SCSI Support
58978137c3cSwdenk		CFG_CMD_SDRAM	* print SDRAM configuration information
590c609719bSwdenk		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
591c609719bSwdenk		CFG_CMD_SPI	* SPI serial bus support
592c609719bSwdenk		CFG_CMD_USB	* USB support
59378137c3cSwdenk		CFG_CMD_VFD	* VFD support (TRAB)
594c609719bSwdenk		CFG_CMD_BSP	* Board SPecific functions
595a3d991bdSwdenk		CFG_CMD_CDP	* Cisco Discover Protocol support
596c609719bSwdenk		-----------------------------------------------
597c609719bSwdenk		CFG_CMD_ALL	all
598c609719bSwdenk
599c609719bSwdenk		CFG_CMD_DFL	Default configuration; at the moment
600c609719bSwdenk				this is includes all commands, except
601c609719bSwdenk				the ones marked with "*" in the list
602c609719bSwdenk				above.
603c609719bSwdenk
604c609719bSwdenk		If you don't define CONFIG_COMMANDS it defaults to
605c609719bSwdenk		CFG_CMD_DFL in include/cmd_confdefs.h. A board can
606c609719bSwdenk		override the default settings in the respective
607c609719bSwdenk		include file.
608c609719bSwdenk
609c609719bSwdenk		EXAMPLE: If you want all functions except of network
610c609719bSwdenk		support you can write:
611c609719bSwdenk
612c609719bSwdenk		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
613c609719bSwdenk
614c609719bSwdenk
615c609719bSwdenk	Note:	Don't enable the "icache" and "dcache" commands
616c609719bSwdenk		(configuration option CFG_CMD_CACHE) unless you know
617c609719bSwdenk		what you (and your U-Boot users) are doing. Data
618c609719bSwdenk		cache cannot be enabled on systems like the 8xx or
619c609719bSwdenk		8260 (where accesses to the IMMR region must be
620c609719bSwdenk		uncached), and it cannot be disabled on all other
621c609719bSwdenk		systems where we (mis-) use the data cache to hold an
622c609719bSwdenk		initial stack and some data.
623c609719bSwdenk
624c609719bSwdenk
625c609719bSwdenk		XXX - this list needs to get updated!
626c609719bSwdenk
627c609719bSwdenk- Watchdog:
628c609719bSwdenk		CONFIG_WATCHDOG
629c609719bSwdenk		If this variable is defined, it enables watchdog
6307152b1d0Swdenk		support. There must be support in the platform specific
631c609719bSwdenk		code for a watchdog. For the 8xx and 8260 CPUs, the
632c609719bSwdenk		SIU Watchdog feature is enabled in the SYPCR
633c609719bSwdenk		register.
634c609719bSwdenk
635c1551ea8Sstroese- U-Boot Version:
636c1551ea8Sstroese		CONFIG_VERSION_VARIABLE
637c1551ea8Sstroese		If this variable is defined, an environment variable
638c1551ea8Sstroese		named "ver" is created by U-Boot showing the U-Boot
639c1551ea8Sstroese		version as printed by the "version" command.
640c1551ea8Sstroese		This variable is readonly.
641c1551ea8Sstroese
642c609719bSwdenk- Real-Time Clock:
643c609719bSwdenk
644c609719bSwdenk		When CFG_CMD_DATE is selected, the type of the RTC
645c609719bSwdenk		has to be selected, too. Define exactly one of the
646c609719bSwdenk		following options:
647c609719bSwdenk
648c609719bSwdenk		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx
649c609719bSwdenk		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC
650c609719bSwdenk		CONFIG_RTC_MC146818	- use MC146818 RTC
6511cb8e980Swdenk		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
652c609719bSwdenk		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
6537f70e853Swdenk		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
6543bac3513Swdenk		CONFIG_RTC_DS164x	- use Dallas DS164x RTC
655c609719bSwdenk
656b37c7e5eSwdenk		Note that if the RTC uses I2C, then the I2C interface
657b37c7e5eSwdenk		must also be configured. See I2C Support, below.
658b37c7e5eSwdenk
659c609719bSwdenk- Timestamp Support:
660c609719bSwdenk
661c609719bSwdenk		When CONFIG_TIMESTAMP is selected, the timestamp
662c609719bSwdenk		(date and time) of an image is printed by image
663c609719bSwdenk		commands like bootm or iminfo. This option is
664c609719bSwdenk		automatically enabled when you select CFG_CMD_DATE .
665c609719bSwdenk
666c609719bSwdenk- Partition Support:
667c609719bSwdenk		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
668c609719bSwdenk		and/or CONFIG_ISO_PARTITION
669c609719bSwdenk
670c609719bSwdenk		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or
671c609719bSwdenk		CFG_CMD_SCSI) you must configure support for at least
672c609719bSwdenk		one partition type as well.
673c609719bSwdenk
674c609719bSwdenk- IDE Reset method:
6754d13cbadSwdenk		CONFIG_IDE_RESET_ROUTINE - this is defined in several
6764d13cbadSwdenk		board configurations files but used nowhere!
677c609719bSwdenk
6784d13cbadSwdenk		CONFIG_IDE_RESET - is this is defined, IDE Reset will
6794d13cbadSwdenk		be performed by calling the function
6804d13cbadSwdenk			ide_set_reset(int reset)
6814d13cbadSwdenk		which has to be defined in a board specific file
682c609719bSwdenk
683c609719bSwdenk- ATAPI Support:
684c609719bSwdenk		CONFIG_ATAPI
685c609719bSwdenk
686c609719bSwdenk		Set this to enable ATAPI support.
687c609719bSwdenk
688c40b2956Swdenk- LBA48 Support
689c40b2956Swdenk		CONFIG_LBA48
690c40b2956Swdenk
691c40b2956Swdenk		Set this to enable support for disks larger than 137GB
692c40b2956Swdenk		Also look at CFG_64BIT_LBA ,CFG_64BIT_VSPRINTF and CFG_64BIT_STRTOUL
693c40b2956Swdenk		Whithout these , LBA48 support uses 32bit variables and will 'only'
694c40b2956Swdenk		support disks up to 2.1TB.
695c40b2956Swdenk
696c40b2956Swdenk		CFG_64BIT_LBA:
697c40b2956Swdenk			When enabled, makes the IDE subsystem use 64bit sector addresses.
698c40b2956Swdenk			Default is 32bit.
699c40b2956Swdenk
700c609719bSwdenk- SCSI Support:
701c609719bSwdenk		At the moment only there is only support for the
702c609719bSwdenk		SYM53C8XX SCSI controller; define
703c609719bSwdenk		CONFIG_SCSI_SYM53C8XX to enable it.
704c609719bSwdenk
705c609719bSwdenk		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
706c609719bSwdenk		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
707c609719bSwdenk		CFG_SCSI_MAX_LUN] can be adjusted to define the
708c609719bSwdenk		maximum numbers of LUNs, SCSI ID's and target
709c609719bSwdenk		devices.
710c609719bSwdenk		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
711c609719bSwdenk
712c609719bSwdenk- NETWORK Support (PCI):
713682011ffSwdenk		CONFIG_E1000
714682011ffSwdenk		Support for Intel 8254x gigabit chips.
715682011ffSwdenk
716c609719bSwdenk		CONFIG_EEPRO100
717c609719bSwdenk		Support for Intel 82557/82559/82559ER chips.
718c609719bSwdenk		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
719c609719bSwdenk		write routine for first time initialisation.
720c609719bSwdenk
721c609719bSwdenk		CONFIG_TULIP
722c609719bSwdenk		Support for Digital 2114x chips.
723c609719bSwdenk		Optional CONFIG_TULIP_SELECT_MEDIA for board specific
724c609719bSwdenk		modem chip initialisation (KS8761/QS6611).
725c609719bSwdenk
726c609719bSwdenk		CONFIG_NATSEMI
727c609719bSwdenk		Support for National dp83815 chips.
728c609719bSwdenk
729c609719bSwdenk		CONFIG_NS8382X
730c609719bSwdenk		Support for National dp8382[01] gigabit chips.
731c609719bSwdenk
73245219c46Swdenk- NETWORK Support (other):
73345219c46Swdenk
73445219c46Swdenk		CONFIG_DRIVER_LAN91C96
73545219c46Swdenk		Support for SMSC's LAN91C96 chips.
73645219c46Swdenk
73745219c46Swdenk			CONFIG_LAN91C96_BASE
73845219c46Swdenk			Define this to hold the physical address
73945219c46Swdenk			of the LAN91C96's I/O space
74045219c46Swdenk
74145219c46Swdenk			CONFIG_LAN91C96_USE_32_BIT
74245219c46Swdenk			Define this to enable 32 bit addressing
74345219c46Swdenk
744f39748aeSwdenk		CONFIG_DRIVER_SMC91111
745f39748aeSwdenk		Support for SMSC's LAN91C111 chip
746f39748aeSwdenk
747f39748aeSwdenk			CONFIG_SMC91111_BASE
748f39748aeSwdenk			Define this to hold the physical address
749f39748aeSwdenk			of the device (I/O space)
750f39748aeSwdenk
751f39748aeSwdenk			CONFIG_SMC_USE_32_BIT
752f39748aeSwdenk			Define this if data bus is 32 bits
753f39748aeSwdenk
754f39748aeSwdenk			CONFIG_SMC_USE_IOFUNCS
755f39748aeSwdenk			Define this to use i/o functions instead of macros
756f39748aeSwdenk			(some hardware wont work with macros)
757f39748aeSwdenk
758c609719bSwdenk- USB Support:
759c609719bSwdenk		At the moment only the UHCI host controller is
7604d13cbadSwdenk		supported (PIP405, MIP405, MPC5200); define
761c609719bSwdenk		CONFIG_USB_UHCI to enable it.
762c609719bSwdenk		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
763c609719bSwdenk		end define CONFIG_USB_STORAGE to enable the USB
764c609719bSwdenk		storage devices.
765c609719bSwdenk		Note:
766c609719bSwdenk		Supported are USB Keyboards and USB Floppy drives
767c609719bSwdenk		(TEAC FD-05PUB).
7684d13cbadSwdenk		MPC5200 USB requires additional defines:
7694d13cbadSwdenk			CONFIG_USB_CLOCK
7704d13cbadSwdenk				for 528 MHz Clock: 0x0001bbbb
7714d13cbadSwdenk			CONFIG_USB_CONFIG
7724d13cbadSwdenk				for differential drivers: 0x00001000
7734d13cbadSwdenk				for single ended drivers: 0x00005000
7744d13cbadSwdenk
775c609719bSwdenk
77671f95118Swdenk- MMC Support:
77771f95118Swdenk		The MMC controller on the Intel PXA is supported. To
77871f95118Swdenk		enable this define CONFIG_MMC. The MMC can be
77971f95118Swdenk		accessed from the boot prompt by mapping the device
78071f95118Swdenk		to physical memory similar to flash. Command line is
78171f95118Swdenk		enabled with CFG_CMD_MMC. The MMC driver also works with
78271f95118Swdenk		the FAT fs. This is enabled with CFG_CMD_FAT.
78371f95118Swdenk
784c609719bSwdenk- Keyboard Support:
785c609719bSwdenk		CONFIG_ISA_KEYBOARD
786c609719bSwdenk
787c609719bSwdenk		Define this to enable standard (PC-Style) keyboard
788c609719bSwdenk		support
789c609719bSwdenk
790c609719bSwdenk		CONFIG_I8042_KBD
791c609719bSwdenk		Standard PC keyboard driver with US (is default) and
792c609719bSwdenk		GERMAN key layout (switch via environment 'keymap=de') support.
793c609719bSwdenk		Export function i8042_kbd_init, i8042_tstc and i8042_getc
794c609719bSwdenk		for cfb_console. Supports cursor blinking.
795c609719bSwdenk
796c609719bSwdenk- Video support:
797c609719bSwdenk		CONFIG_VIDEO
798c609719bSwdenk
799c609719bSwdenk		Define this to enable video support (for output to
800c609719bSwdenk		video).
801c609719bSwdenk
802c609719bSwdenk		CONFIG_VIDEO_CT69000
803c609719bSwdenk
804c609719bSwdenk		Enable Chips & Technologies 69000 Video chip
805c609719bSwdenk
806c609719bSwdenk		CONFIG_VIDEO_SMI_LYNXEM
807eeb1b77bSwdenk		Enable Silicon Motion SMI 712/710/810 Video chip. The
808eeb1b77bSwdenk		video output is selected via environment 'videoout'
809eeb1b77bSwdenk		(1 = LCD and 2 = CRT). If videoout is undefined, CRT is
810eeb1b77bSwdenk		assumed.
811c609719bSwdenk
812eeb1b77bSwdenk		For the CT69000 and SMI_LYNXEM drivers, videomode is
813eeb1b77bSwdenk		selected via environment 'videomode'. Two diferent ways
814eeb1b77bSwdenk		are possible:
815eeb1b77bSwdenk		- "videomode=num"   'num' is a standard LiLo mode numbers.
816eeb1b77bSwdenk		Following standard modes are supported	(* is default):
817eeb1b77bSwdenk
818eeb1b77bSwdenk		      Colors	640x480 800x600 1024x768 1152x864 1280x1024
819eeb1b77bSwdenk		-------------+---------------------------------------------
820eeb1b77bSwdenk		      8 bits |	0x301*	0x303	 0x305	  0x161	    0x307
821eeb1b77bSwdenk		     15 bits |	0x310	0x313	 0x316	  0x162	    0x319
822eeb1b77bSwdenk		     16 bits |	0x311	0x314	 0x317	  0x163	    0x31A
823eeb1b77bSwdenk		     24 bits |	0x312	0x315	 0x318	    ?	    0x31B
824eeb1b77bSwdenk		-------------+---------------------------------------------
825c609719bSwdenk		(i.e. setenv videomode 317; saveenv; reset;)
826c609719bSwdenk
827eeb1b77bSwdenk		- "videomode=bootargs" all the video parameters are parsed
828eeb1b77bSwdenk		from the bootargs. (See drivers/videomodes.c)
829eeb1b77bSwdenk
830eeb1b77bSwdenk
831a6c7ad2fSwdenk		CONFIG_VIDEO_SED13806
832a6c7ad2fSwdenk		Enable Epson SED13806 driver. This driver supports 8bpp
833a6c7ad2fSwdenk		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
834a6c7ad2fSwdenk		or CONFIG_VIDEO_SED13806_16BPP
835a6c7ad2fSwdenk
836682011ffSwdenk- Keyboard Support:
837682011ffSwdenk		CONFIG_KEYBOARD
838682011ffSwdenk
839682011ffSwdenk		Define this to enable a custom keyboard support.
840682011ffSwdenk		This simply calls drv_keyboard_init() which must be
841682011ffSwdenk		defined in your board-specific files.
842682011ffSwdenk		The only board using this so far is RBC823.
843a6c7ad2fSwdenk
844c609719bSwdenk- LCD Support:	CONFIG_LCD
845c609719bSwdenk
846c609719bSwdenk		Define this to enable LCD support (for output to LCD
847c609719bSwdenk		display); also select one of the supported displays
848c609719bSwdenk		by defining one of these:
849c609719bSwdenk
850fd3103bbSwdenk		CONFIG_NEC_NL6448AC33:
851c609719bSwdenk
852fd3103bbSwdenk			NEC NL6448AC33-18. Active, color, single scan.
853c609719bSwdenk
854fd3103bbSwdenk		CONFIG_NEC_NL6448BC20
855c609719bSwdenk
856fd3103bbSwdenk			NEC NL6448BC20-08. 6.5", 640x480.
857fd3103bbSwdenk			Active, color, single scan.
858fd3103bbSwdenk
859fd3103bbSwdenk		CONFIG_NEC_NL6448BC33_54
860fd3103bbSwdenk
861fd3103bbSwdenk			NEC NL6448BC33-54. 10.4", 640x480.
862c609719bSwdenk			Active, color, single scan.
863c609719bSwdenk
864c609719bSwdenk		CONFIG_SHARP_16x9
865c609719bSwdenk
866c609719bSwdenk			Sharp 320x240. Active, color, single scan.
867c609719bSwdenk			It isn't 16x9, and I am not sure what it is.
868c609719bSwdenk
869c609719bSwdenk		CONFIG_SHARP_LQ64D341
870c609719bSwdenk
871c609719bSwdenk			Sharp LQ64D341 display, 640x480.
872c609719bSwdenk			Active, color, single scan.
873c609719bSwdenk
874c609719bSwdenk		CONFIG_HLD1045
875c609719bSwdenk
876c609719bSwdenk			HLD1045 display, 640x480.
877c609719bSwdenk			Active, color, single scan.
878c609719bSwdenk
879c609719bSwdenk		CONFIG_OPTREX_BW
880c609719bSwdenk
881c609719bSwdenk			Optrex	 CBL50840-2 NF-FW 99 22 M5
882c609719bSwdenk			or
883c609719bSwdenk			Hitachi	 LMG6912RPFC-00T
884c609719bSwdenk			or
885c609719bSwdenk			Hitachi	 SP14Q002
886c609719bSwdenk
887c609719bSwdenk			320x240. Black & white.
888c609719bSwdenk
889c609719bSwdenk		Normally display is black on white background; define
890c609719bSwdenk		CFG_WHITE_ON_BLACK to get it inverted.
891c609719bSwdenk
8927152b1d0Swdenk- Splash Screen Support: CONFIG_SPLASH_SCREEN
893d791b1dcSwdenk
894d791b1dcSwdenk		If this option is set, the environment is checked for
895d791b1dcSwdenk		a variable "splashimage". If found, the usual display
896d791b1dcSwdenk		of logo, copyright and system information on the LCD
897d791b1dcSwdenk		is supressed and the BMP image at the address
898d791b1dcSwdenk		specified in "splashimage" is loaded instead. The
899d791b1dcSwdenk		console is redirected to the "nulldev", too. This
900d791b1dcSwdenk		allows for a "silent" boot where a splash screen is
901d791b1dcSwdenk		loaded very quickly after power-on.
902d791b1dcSwdenk
903c29fdfc1Swdenk- Compression support:
904c29fdfc1Swdenk		CONFIG_BZIP2
905c29fdfc1Swdenk
906c29fdfc1Swdenk		If this option is set, support for bzip2 compressed
907c29fdfc1Swdenk		images is included. If not, only uncompressed and gzip
908c29fdfc1Swdenk		compressed images are supported.
909c29fdfc1Swdenk
910c29fdfc1Swdenk		NOTE: the bzip2 algorithm requires a lot of RAM, so
911c29fdfc1Swdenk		the malloc area (as defined by CFG_MALLOC_LEN) should
912c29fdfc1Swdenk		be at least 4MB.
913d791b1dcSwdenk
91417ea1177Swdenk- MII/PHY support:
91517ea1177Swdenk		CONFIG_PHY_ADDR
91617ea1177Swdenk
91717ea1177Swdenk		The address of PHY on MII bus.
91817ea1177Swdenk
91917ea1177Swdenk		CONFIG_PHY_CLOCK_FREQ (ppc4xx)
92017ea1177Swdenk
92117ea1177Swdenk		The clock frequency of the MII bus
92217ea1177Swdenk
92317ea1177Swdenk		CONFIG_PHY_GIGE
92417ea1177Swdenk
92517ea1177Swdenk		If this option is set, support for speed/duplex
92617ea1177Swdenk		detection of Gigabit PHY is included.
92717ea1177Swdenk
92817ea1177Swdenk		CONFIG_PHY_RESET_DELAY
92917ea1177Swdenk
93017ea1177Swdenk		Some PHY like Intel LXT971A need extra delay after
93117ea1177Swdenk		reset before any MII register access is possible.
93217ea1177Swdenk		For such PHY, set this option to the usec delay
93317ea1177Swdenk		required. (minimum 300usec for LXT971A)
93417ea1177Swdenk
93517ea1177Swdenk		CONFIG_PHY_CMD_DELAY (ppc4xx)
93617ea1177Swdenk
93717ea1177Swdenk		Some PHY like Intel LXT971A need extra delay after
93817ea1177Swdenk		command issued before MII status register can be read
93917ea1177Swdenk
940c609719bSwdenk- Ethernet address:
941c609719bSwdenk		CONFIG_ETHADDR
942c609719bSwdenk		CONFIG_ETH2ADDR
943c609719bSwdenk		CONFIG_ETH3ADDR
944c609719bSwdenk
945c609719bSwdenk		Define a default value for ethernet address to use
946c609719bSwdenk		for the respective ethernet interface, in case this
947c609719bSwdenk		is not determined automatically.
948c609719bSwdenk
949c609719bSwdenk- IP address:
950c609719bSwdenk		CONFIG_IPADDR
951c609719bSwdenk
952c609719bSwdenk		Define a default value for the IP address to use for
953c609719bSwdenk		the default ethernet interface, in case this is not
954c609719bSwdenk		determined through e.g. bootp.
955c609719bSwdenk
956c609719bSwdenk- Server IP address:
957c609719bSwdenk		CONFIG_SERVERIP
958c609719bSwdenk
959c609719bSwdenk		Defines a default value for theIP address of a TFTP
960c609719bSwdenk		server to contact when using the "tftboot" command.
961c609719bSwdenk
962c609719bSwdenk- BOOTP Recovery Mode:
963c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY
964c609719bSwdenk
965c609719bSwdenk		If you have many targets in a network that try to
966c609719bSwdenk		boot using BOOTP, you may want to avoid that all
967c609719bSwdenk		systems send out BOOTP requests at precisely the same
968c609719bSwdenk		moment (which would happen for instance at recovery
969c609719bSwdenk		from a power failure, when all systems will try to
970c609719bSwdenk		boot, thus flooding the BOOTP server. Defining
971c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
972c609719bSwdenk		inserted before sending out BOOTP requests. The
973c609719bSwdenk		following delays are insterted then:
974c609719bSwdenk
975c609719bSwdenk		1st BOOTP request:	delay 0 ... 1 sec
976c609719bSwdenk		2nd BOOTP request:	delay 0 ... 2 sec
977c609719bSwdenk		3rd BOOTP request:	delay 0 ... 4 sec
978c609719bSwdenk		4th and following
979c609719bSwdenk		BOOTP requests:		delay 0 ... 8 sec
980c609719bSwdenk
981fe389a82Sstroese- DHCP Advanced Options:
982fe389a82Sstroese		CONFIG_BOOTP_MASK
983fe389a82Sstroese
984fe389a82Sstroese		You can fine tune the DHCP functionality by adding
985fe389a82Sstroese		these flags to the CONFIG_BOOTP_MASK define:
986fe389a82Sstroese
987fe389a82Sstroese		CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
988fe389a82Sstroese		serverip from a DHCP server, it is possible that more
989fe389a82Sstroese		than one DNS serverip is offered to the client.
990fe389a82Sstroese		If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
991fe389a82Sstroese		serverip will be stored in the additional environment
992fe389a82Sstroese		variable "dnsip2". The first DNS serverip is always
993fe389a82Sstroese		stored in the variable "dnsip", when CONFIG_BOOTP_DNS
994fe389a82Sstroese		is added to the CONFIG_BOOTP_MASK.
995fe389a82Sstroese
996fe389a82Sstroese		CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
997fe389a82Sstroese		to do a dynamic update of a DNS server. To do this, they
998fe389a82Sstroese		need the hostname of the DHCP requester.
999fe389a82Sstroese		If CONFIG_BOOP_SEND_HOSTNAME is added to the
1000fe389a82Sstroese		CONFIG_BOOTP_MASK, the content of the "hostname"
1001fe389a82Sstroese		environment variable is passed as option 12 to
1002fe389a82Sstroese		the DHCP server.
1003fe389a82Sstroese
1004a3d991bdSwdenk - CDP Options:
1005a3d991bdSwdenk		CONFIG_CDP_DEVICE_ID
1006a3d991bdSwdenk
1007a3d991bdSwdenk		The device id used in CDP trigger frames.
1008a3d991bdSwdenk
1009a3d991bdSwdenk		CONFIG_CDP_DEVICE_ID_PREFIX
1010a3d991bdSwdenk
1011a3d991bdSwdenk		A two character string which is prefixed to the MAC address
1012a3d991bdSwdenk		of the device.
1013a3d991bdSwdenk
1014a3d991bdSwdenk		CONFIG_CDP_PORT_ID
1015a3d991bdSwdenk
1016a3d991bdSwdenk		A printf format string which contains the ascii name of
1017a3d991bdSwdenk		the port. Normally is set to "eth%d" which sets
1018a3d991bdSwdenk		eth0 for the first ethernet, eth1 for the second etc.
1019a3d991bdSwdenk
1020a3d991bdSwdenk		CONFIG_CDP_CAPABILITIES
1021a3d991bdSwdenk
1022a3d991bdSwdenk		A 32bit integer which indicates the device capabilities;
1023a3d991bdSwdenk		0x00000010 for a normal host which does not forwards.
1024a3d991bdSwdenk
1025a3d991bdSwdenk		CONFIG_CDP_VERSION
1026a3d991bdSwdenk
1027a3d991bdSwdenk		An ascii string containing the version of the software.
1028a3d991bdSwdenk
1029a3d991bdSwdenk		CONFIG_CDP_PLATFORM
1030a3d991bdSwdenk
1031a3d991bdSwdenk		An ascii string containing the name of the platform.
1032a3d991bdSwdenk
1033a3d991bdSwdenk		CONFIG_CDP_TRIGGER
1034a3d991bdSwdenk
1035a3d991bdSwdenk		A 32bit integer sent on the trigger.
1036a3d991bdSwdenk
1037a3d991bdSwdenk		CONFIG_CDP_POWER_CONSUMPTION
1038a3d991bdSwdenk
1039a3d991bdSwdenk		A 16bit integer containing the power consumption of the
1040a3d991bdSwdenk		device in .1 of milliwatts.
1041a3d991bdSwdenk
1042a3d991bdSwdenk		CONFIG_CDP_APPLIANCE_VLAN_TYPE
1043a3d991bdSwdenk
1044a3d991bdSwdenk		A byte containing the id of the VLAN.
1045a3d991bdSwdenk
1046c609719bSwdenk- Status LED:	CONFIG_STATUS_LED
1047c609719bSwdenk
1048c609719bSwdenk		Several configurations allow to display the current
1049c609719bSwdenk		status using a LED. For instance, the LED will blink
1050c609719bSwdenk		fast while running U-Boot code, stop blinking as
1051c609719bSwdenk		soon as a reply to a BOOTP request was received, and
1052c609719bSwdenk		start blinking slow once the Linux kernel is running
1053c609719bSwdenk		(supported by a status LED driver in the Linux
1054c609719bSwdenk		kernel). Defining CONFIG_STATUS_LED enables this
1055c609719bSwdenk		feature in U-Boot.
1056c609719bSwdenk
1057c609719bSwdenk- CAN Support:	CONFIG_CAN_DRIVER
1058c609719bSwdenk
1059c609719bSwdenk		Defining CONFIG_CAN_DRIVER enables CAN driver support
1060c609719bSwdenk		on those systems that support this (optional)
1061c609719bSwdenk		feature, like the TQM8xxL modules.
1062c609719bSwdenk
1063c609719bSwdenk- I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1064c609719bSwdenk
1065b37c7e5eSwdenk		These enable I2C serial bus commands. Defining either of
1066b37c7e5eSwdenk		(but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1067b37c7e5eSwdenk		include the appropriate I2C driver for the selected cpu.
1068c609719bSwdenk
1069b37c7e5eSwdenk		This will allow you to use i2c commands at the u-boot
1070b37c7e5eSwdenk		command line (as long as you set CFG_CMD_I2C in
1071b37c7e5eSwdenk		CONFIG_COMMANDS) and communicate with i2c based realtime
1072b37c7e5eSwdenk		clock chips. See common/cmd_i2c.c for a description of the
1073c609719bSwdenk		command line interface.
1074c609719bSwdenk
1075b37c7e5eSwdenk		CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
1076c609719bSwdenk
1077b37c7e5eSwdenk		CONFIG_SOFT_I2C configures u-boot to use a software (aka
1078b37c7e5eSwdenk		bit-banging) driver instead of CPM or similar hardware
1079b37c7e5eSwdenk		support for I2C.
1080c609719bSwdenk
1081b37c7e5eSwdenk		There are several other quantities that must also be
1082b37c7e5eSwdenk		defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1083c609719bSwdenk
1084b37c7e5eSwdenk		In both cases you will need to define CFG_I2C_SPEED
1085b37c7e5eSwdenk		to be the frequency (in Hz) at which you wish your i2c bus
1086b37c7e5eSwdenk		to run and CFG_I2C_SLAVE to be the address of this node (ie
1087b37c7e5eSwdenk		the cpu's i2c node address).
1088c609719bSwdenk
1089b37c7e5eSwdenk		Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1090b37c7e5eSwdenk		sets the cpu up as a master node and so its address should
1091b37c7e5eSwdenk		therefore be cleared to 0 (See, eg, MPC823e User's Manual
1092b37c7e5eSwdenk		p.16-473). So, set CFG_I2C_SLAVE to 0.
1093b37c7e5eSwdenk
1094b37c7e5eSwdenk		That's all that's required for CONFIG_HARD_I2C.
1095b37c7e5eSwdenk
1096b37c7e5eSwdenk		If you use the software i2c interface (CONFIG_SOFT_I2C)
1097b37c7e5eSwdenk		then the following macros need to be defined (examples are
1098b37c7e5eSwdenk		from include/configs/lwmon.h):
1099c609719bSwdenk
1100c609719bSwdenk		I2C_INIT
1101c609719bSwdenk
1102b37c7e5eSwdenk		(Optional). Any commands necessary to enable the I2C
1103c609719bSwdenk		controller or configure ports.
1104c609719bSwdenk
1105b37c7e5eSwdenk		eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |=	PB_SCL)
1106b37c7e5eSwdenk
1107c609719bSwdenk		I2C_PORT
1108c609719bSwdenk
1109c609719bSwdenk		(Only for MPC8260 CPU). The I/O port to use (the code
1110c609719bSwdenk		assumes both bits are on the same port). Valid values
1111c609719bSwdenk		are 0..3 for ports A..D.
1112c609719bSwdenk
1113c609719bSwdenk		I2C_ACTIVE
1114c609719bSwdenk
1115c609719bSwdenk		The code necessary to make the I2C data line active
1116c609719bSwdenk		(driven).  If the data line is open collector, this
1117c609719bSwdenk		define can be null.
1118c609719bSwdenk
1119b37c7e5eSwdenk		eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |=  PB_SDA)
1120b37c7e5eSwdenk
1121c609719bSwdenk		I2C_TRISTATE
1122c609719bSwdenk
1123c609719bSwdenk		The code necessary to make the I2C data line tri-stated
1124c609719bSwdenk		(inactive).  If the data line is open collector, this
1125c609719bSwdenk		define can be null.
1126c609719bSwdenk
1127b37c7e5eSwdenk		eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1128b37c7e5eSwdenk
1129c609719bSwdenk		I2C_READ
1130c609719bSwdenk
1131c609719bSwdenk		Code that returns TRUE if the I2C data line is high,
1132c609719bSwdenk		FALSE if it is low.
1133c609719bSwdenk
1134b37c7e5eSwdenk		eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1135b37c7e5eSwdenk
1136c609719bSwdenk		I2C_SDA(bit)
1137c609719bSwdenk
1138c609719bSwdenk		If <bit> is TRUE, sets the I2C data line high. If it
1139c609719bSwdenk		is FALSE, it clears it (low).
1140c609719bSwdenk
1141b37c7e5eSwdenk		eg: #define I2C_SDA(bit) \
1142b37c7e5eSwdenk			if(bit) immr->im_cpm.cp_pbdat |=  PB_SDA; \
1143b37c7e5eSwdenk			else	immr->im_cpm.cp_pbdat &= ~PB_SDA
1144b37c7e5eSwdenk
1145c609719bSwdenk		I2C_SCL(bit)
1146c609719bSwdenk
1147c609719bSwdenk		If <bit> is TRUE, sets the I2C clock line high. If it
1148c609719bSwdenk		is FALSE, it clears it (low).
1149c609719bSwdenk
1150b37c7e5eSwdenk		eg: #define I2C_SCL(bit) \
1151b37c7e5eSwdenk			if(bit) immr->im_cpm.cp_pbdat |=  PB_SCL; \
1152b37c7e5eSwdenk			else	immr->im_cpm.cp_pbdat &= ~PB_SCL
1153b37c7e5eSwdenk
1154c609719bSwdenk		I2C_DELAY
1155c609719bSwdenk
1156c609719bSwdenk		This delay is invoked four times per clock cycle so this
1157c609719bSwdenk		controls the rate of data transfer.  The data rate thus
1158b37c7e5eSwdenk		is 1 / (I2C_DELAY * 4). Often defined to be something
1159b37c7e5eSwdenk		like:
1160b37c7e5eSwdenk
1161b37c7e5eSwdenk		#define I2C_DELAY  udelay(2)
1162c609719bSwdenk
116347cd00faSwdenk		CFG_I2C_INIT_BOARD
116447cd00faSwdenk
116547cd00faSwdenk		When a board is reset during an i2c bus transfer
116647cd00faSwdenk		chips might think that the current transfer is still
116747cd00faSwdenk		in progress. On some boards it is possible to access
116847cd00faSwdenk		the i2c SCLK line directly, either by using the
116947cd00faSwdenk		processor pin as a GPIO or by having a second pin
117047cd00faSwdenk		connected to the bus. If this option is defined a
117147cd00faSwdenk		custom i2c_init_board() routine in boards/xxx/board.c
117247cd00faSwdenk		is run early in the boot sequence.
117347cd00faSwdenk
117417ea1177Swdenk		CONFIG_I2CFAST (PPC405GP|PPC405EP only)
117517ea1177Swdenk
117617ea1177Swdenk		This option enables configuration of bi_iic_fast[] flags
117717ea1177Swdenk		in u-boot bd_info structure based on u-boot environment
117817ea1177Swdenk		variable "i2cfast". (see also i2cfast)
117917ea1177Swdenk
1180c609719bSwdenk- SPI Support:	CONFIG_SPI
1181c609719bSwdenk
1182c609719bSwdenk		Enables SPI driver (so far only tested with
1183c609719bSwdenk		SPI EEPROM, also an instance works with Crystal A/D and
1184c609719bSwdenk		D/As on the SACSng board)
1185c609719bSwdenk
1186c609719bSwdenk		CONFIG_SPI_X
1187c609719bSwdenk
1188c609719bSwdenk		Enables extended (16-bit) SPI EEPROM addressing.
1189c609719bSwdenk		(symmetrical to CONFIG_I2C_X)
1190c609719bSwdenk
1191c609719bSwdenk		CONFIG_SOFT_SPI
1192c609719bSwdenk
1193c609719bSwdenk		Enables a software (bit-bang) SPI driver rather than
1194c609719bSwdenk		using hardware support. This is a general purpose
1195c609719bSwdenk		driver that only requires three general I/O port pins
1196c609719bSwdenk		(two outputs, one input) to function. If this is
1197c609719bSwdenk		defined, the board configuration must define several
1198c609719bSwdenk		SPI configuration items (port pins to use, etc). For
1199c609719bSwdenk		an example, see include/configs/sacsng.h.
1200c609719bSwdenk
1201c609719bSwdenk- FPGA Support: CONFIG_FPGA_COUNT
1202c609719bSwdenk
1203c609719bSwdenk		Specify the number of FPGA devices to support.
1204c609719bSwdenk
1205c609719bSwdenk		CONFIG_FPGA
1206c609719bSwdenk
1207c609719bSwdenk		Used to specify the types of FPGA devices.  For example,
1208c609719bSwdenk		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
1209c609719bSwdenk
1210c609719bSwdenk		CFG_FPGA_PROG_FEEDBACK
1211c609719bSwdenk
1212c609719bSwdenk		Enable printing of hash marks during FPGA configuration.
1213c609719bSwdenk
1214c609719bSwdenk		CFG_FPGA_CHECK_BUSY
1215c609719bSwdenk
1216c609719bSwdenk		Enable checks on FPGA configuration interface busy
1217c609719bSwdenk		status by the configuration function. This option
1218c609719bSwdenk		will require a board or device specific function to
1219c609719bSwdenk		be written.
1220c609719bSwdenk
1221c609719bSwdenk		CONFIG_FPGA_DELAY
1222c609719bSwdenk
1223c609719bSwdenk		If defined, a function that provides delays in the FPGA
1224c609719bSwdenk		configuration driver.
1225c609719bSwdenk
1226c609719bSwdenk		CFG_FPGA_CHECK_CTRLC
1227c609719bSwdenk		Allow Control-C to interrupt FPGA configuration
1228c609719bSwdenk
1229c609719bSwdenk		CFG_FPGA_CHECK_ERROR
1230c609719bSwdenk
1231c609719bSwdenk		Check for configuration errors during FPGA bitfile
1232c609719bSwdenk		loading. For example, abort during Virtex II
1233c609719bSwdenk		configuration if the INIT_B line goes low (which
1234c609719bSwdenk		indicated a CRC error).
1235c609719bSwdenk
1236c609719bSwdenk		CFG_FPGA_WAIT_INIT
1237c609719bSwdenk
1238c609719bSwdenk		Maximum time to wait for the INIT_B line to deassert
1239c609719bSwdenk		after PROB_B has been deasserted during a Virtex II
1240c609719bSwdenk		FPGA configuration sequence. The default time is 500
1241c609719bSwdenk		mS.
1242c609719bSwdenk
1243c609719bSwdenk		CFG_FPGA_WAIT_BUSY
1244c609719bSwdenk
1245c609719bSwdenk		Maximum time to wait for BUSY to deassert during
1246c609719bSwdenk		Virtex II FPGA configuration. The default is 5 mS.
1247c609719bSwdenk
1248c609719bSwdenk		CFG_FPGA_WAIT_CONFIG
1249c609719bSwdenk
1250c609719bSwdenk		Time to wait after FPGA configuration. The default is
1251c609719bSwdenk		200 mS.
1252c609719bSwdenk
1253c609719bSwdenk- Configuration Management:
1254c609719bSwdenk		CONFIG_IDENT_STRING
1255c609719bSwdenk
1256c609719bSwdenk		If defined, this string will be added to the U-Boot
1257c609719bSwdenk		version information (U_BOOT_VERSION)
1258c609719bSwdenk
1259c609719bSwdenk- Vendor Parameter Protection:
1260c609719bSwdenk
1261c609719bSwdenk		U-Boot considers the values of the environment
1262c609719bSwdenk		variables "serial#" (Board Serial Number) and
12637152b1d0Swdenk		"ethaddr" (Ethernet Address) to be parameters that
1264c609719bSwdenk		are set once by the board vendor / manufacturer, and
1265c609719bSwdenk		protects these variables from casual modification by
1266c609719bSwdenk		the user. Once set, these variables are read-only,
1267c609719bSwdenk		and write or delete attempts are rejected. You can
1268c609719bSwdenk		change this behviour:
1269c609719bSwdenk
1270c609719bSwdenk		If CONFIG_ENV_OVERWRITE is #defined in your config
1271c609719bSwdenk		file, the write protection for vendor parameters is
127247cd00faSwdenk		completely disabled. Anybody can change or delete
1273c609719bSwdenk		these parameters.
1274c609719bSwdenk
1275c609719bSwdenk		Alternatively, if you #define _both_ CONFIG_ETHADDR
1276c609719bSwdenk		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1277c609719bSwdenk		ethernet address is installed in the environment,
1278c609719bSwdenk		which can be changed exactly ONCE by the user. [The
1279c609719bSwdenk		serial# is unaffected by this, i. e. it remains
1280c609719bSwdenk		read-only.]
1281c609719bSwdenk
1282c609719bSwdenk- Protected RAM:
1283c609719bSwdenk		CONFIG_PRAM
1284c609719bSwdenk
1285c609719bSwdenk		Define this variable to enable the reservation of
1286c609719bSwdenk		"protected RAM", i. e. RAM which is not overwritten
1287c609719bSwdenk		by U-Boot. Define CONFIG_PRAM to hold the number of
1288c609719bSwdenk		kB you want to reserve for pRAM. You can overwrite
1289c609719bSwdenk		this default value by defining an environment
1290c609719bSwdenk		variable "pram" to the number of kB you want to
1291c609719bSwdenk		reserve. Note that the board info structure will
1292c609719bSwdenk		still show the full amount of RAM. If pRAM is
1293c609719bSwdenk		reserved, a new environment variable "mem" will
1294c609719bSwdenk		automatically be defined to hold the amount of
1295c609719bSwdenk		remaining RAM in a form that can be passed as boot
1296c609719bSwdenk		argument to Linux, for instance like that:
1297c609719bSwdenk
1298c609719bSwdenk			setenv bootargs ... mem=\$(mem)
1299c609719bSwdenk			saveenv
1300c609719bSwdenk
1301c609719bSwdenk		This way you can tell Linux not to use this memory,
1302c609719bSwdenk		either, which results in a memory region that will
1303c609719bSwdenk		not be affected by reboots.
1304c609719bSwdenk
1305c609719bSwdenk		*WARNING* If your board configuration uses automatic
1306c609719bSwdenk		detection of the RAM size, you must make sure that
1307c609719bSwdenk		this memory test is non-destructive. So far, the
1308c609719bSwdenk		following board configurations are known to be
1309c609719bSwdenk		"pRAM-clean":
1310c609719bSwdenk
1311c609719bSwdenk			ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1312c609719bSwdenk			HERMES, IP860, RPXlite, LWMON, LANTEC,
1313c609719bSwdenk			PCU_E, FLAGADM, TQM8260
1314c609719bSwdenk
1315c609719bSwdenk- Error Recovery:
1316c609719bSwdenk		CONFIG_PANIC_HANG
1317c609719bSwdenk
1318c609719bSwdenk		Define this variable to stop the system in case of a
1319c609719bSwdenk		fatal error, so that you have to reset it manually.
1320c609719bSwdenk		This is probably NOT a good idea for an embedded
1321c609719bSwdenk		system where you want to system to reboot
1322c609719bSwdenk		automatically as fast as possible, but it may be
1323c609719bSwdenk		useful during development since you can try to debug
1324c609719bSwdenk		the conditions that lead to the situation.
1325c609719bSwdenk
1326c609719bSwdenk		CONFIG_NET_RETRY_COUNT
1327c609719bSwdenk
1328c609719bSwdenk		This variable defines the number of retries for
1329c609719bSwdenk		network operations like ARP, RARP, TFTP, or BOOTP
1330c609719bSwdenk		before giving up the operation. If not defined, a
1331c609719bSwdenk		default value of 5 is used.
1332c609719bSwdenk
1333c609719bSwdenk- Command Interpreter:
133404a85b3bSwdenk		CFG_AUTO_COMPLETE
133504a85b3bSwdenk
133604a85b3bSwdenk		Enable auto completion of commands using TAB.
133704a85b3bSwdenk
1338c609719bSwdenk		CFG_HUSH_PARSER
1339c609719bSwdenk
1340c609719bSwdenk		Define this variable to enable the "hush" shell (from
1341c609719bSwdenk		Busybox) as command line interpreter, thus enabling
1342c609719bSwdenk		powerful command line syntax like
1343c609719bSwdenk		if...then...else...fi conditionals or `&&' and '||'
1344c609719bSwdenk		constructs ("shell scripts").
1345c609719bSwdenk
1346c609719bSwdenk		If undefined, you get the old, much simpler behaviour
1347c609719bSwdenk		with a somewhat smaller memory footprint.
1348c609719bSwdenk
1349c609719bSwdenk
1350c609719bSwdenk		CFG_PROMPT_HUSH_PS2
1351c609719bSwdenk
1352c609719bSwdenk		This defines the secondary prompt string, which is
1353c609719bSwdenk		printed when the command interpreter needs more input
1354c609719bSwdenk		to complete a command. Usually "> ".
1355c609719bSwdenk
1356c609719bSwdenk	Note:
1357c609719bSwdenk
1358c609719bSwdenk		In the current implementation, the local variables
1359c609719bSwdenk		space and global environment variables space are
1360c609719bSwdenk		separated. Local variables are those you define by
13613b57fe0aSwdenk		simply typing `name=value'. To access a local
1362c609719bSwdenk		variable later on, you have write `$name' or
13633b57fe0aSwdenk		`${name}'; to execute the contents of a variable
13643b57fe0aSwdenk		directly type `$name' at the command prompt.
1365c609719bSwdenk
1366c609719bSwdenk		Global environment variables are those you use
1367c609719bSwdenk		setenv/printenv to work with. To run a command stored
1368c609719bSwdenk		in such a variable, you need to use the run command,
1369c609719bSwdenk		and you must not use the '$' sign to access them.
1370c609719bSwdenk
1371c609719bSwdenk		To store commands and special characters in a
1372c609719bSwdenk		variable, please use double quotation marks
1373c609719bSwdenk		surrounding the whole text of the variable, instead
1374c609719bSwdenk		of the backslashes before semicolons and special
1375c609719bSwdenk		symbols.
1376c609719bSwdenk
1377a8c7c708Swdenk- Default Environment:
1378c609719bSwdenk		CONFIG_EXTRA_ENV_SETTINGS
1379c609719bSwdenk
1380c609719bSwdenk		Define this to contain any number of null terminated
1381c609719bSwdenk		strings (variable = value pairs) that will be part of
13827152b1d0Swdenk		the default environment compiled into the boot image.
13832262cfeeSwdenk
1384c609719bSwdenk		For example, place something like this in your
1385c609719bSwdenk		board's config file:
1386c609719bSwdenk
1387c609719bSwdenk		#define CONFIG_EXTRA_ENV_SETTINGS \
1388c609719bSwdenk			"myvar1=value1\0" \
1389c609719bSwdenk			"myvar2=value2\0"
1390c609719bSwdenk
1391c609719bSwdenk		Warning: This method is based on knowledge about the
1392c609719bSwdenk		internal format how the environment is stored by the
13932262cfeeSwdenk		U-Boot code. This is NOT an official, exported
1394c609719bSwdenk		interface! Although it is unlikely that this format
13957152b1d0Swdenk		will change soon, there is no guarantee either.
1396c609719bSwdenk		You better know what you are doing here.
1397c609719bSwdenk
1398c609719bSwdenk		Note: overly (ab)use of the default environment is
1399c609719bSwdenk		discouraged. Make sure to check other ways to preset
1400c609719bSwdenk		the environment like the autoscript function or the
1401c609719bSwdenk		boot command first.
1402c609719bSwdenk
1403a8c7c708Swdenk- DataFlash Support:
14042abbe075Swdenk		CONFIG_HAS_DATAFLASH
14052abbe075Swdenk
14062abbe075Swdenk		Defining this option enables DataFlash features and
14072abbe075Swdenk		allows to read/write in Dataflash via the standard
14082abbe075Swdenk		commands cp, md...
14092abbe075Swdenk
14103f85ce27Swdenk- SystemACE Support:
14113f85ce27Swdenk		CONFIG_SYSTEMACE
14123f85ce27Swdenk
14133f85ce27Swdenk		Adding this option adds support for Xilinx SystemACE
14143f85ce27Swdenk		chips attached via some sort of local bus. The address
14153f85ce27Swdenk		of the chip must alsh be defined in the
14163f85ce27Swdenk		CFG_SYSTEMACE_BASE macro. For example:
14173f85ce27Swdenk
14183f85ce27Swdenk		#define CONFIG_SYSTEMACE
14193f85ce27Swdenk		#define CFG_SYSTEMACE_BASE 0xf0000000
14203f85ce27Swdenk
14213f85ce27Swdenk		When SystemACE support is added, the "ace" device type
14223f85ce27Swdenk		becomes available to the fat commands, i.e. fatls.
14233f85ce27Swdenk
1424a8c7c708Swdenk- Show boot progress:
1425c609719bSwdenk		CONFIG_SHOW_BOOT_PROGRESS
1426c609719bSwdenk
1427c609719bSwdenk		Defining this option allows to add some board-
1428c609719bSwdenk		specific code (calling a user-provided function
1429c609719bSwdenk		"show_boot_progress(int)") that enables you to show
1430c609719bSwdenk		the system's boot progress on some display (for
1431c609719bSwdenk		example, some LED's) on your board. At the moment,
1432c609719bSwdenk		the following checkpoints are implemented:
1433c609719bSwdenk
1434c609719bSwdenk  Arg	Where			When
1435c609719bSwdenk    1	common/cmd_bootm.c	before attempting to boot an image
1436c609719bSwdenk   -1	common/cmd_bootm.c	Image header has bad	 magic number
1437c609719bSwdenk    2	common/cmd_bootm.c	Image header has correct magic number
1438c609719bSwdenk   -2	common/cmd_bootm.c	Image header has bad	 checksum
1439c609719bSwdenk    3	common/cmd_bootm.c	Image header has correct checksum
1440c609719bSwdenk   -3	common/cmd_bootm.c	Image data   has bad	 checksum
1441c609719bSwdenk    4	common/cmd_bootm.c	Image data   has correct checksum
1442c609719bSwdenk   -4	common/cmd_bootm.c	Image is for unsupported architecture
1443c609719bSwdenk    5	common/cmd_bootm.c	Architecture check OK
1444c609719bSwdenk   -5	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1445c609719bSwdenk    6	common/cmd_bootm.c	Image Type check OK
1446c609719bSwdenk   -6	common/cmd_bootm.c	gunzip uncompression error
1447c609719bSwdenk   -7	common/cmd_bootm.c	Unimplemented compression type
1448c609719bSwdenk    7	common/cmd_bootm.c	Uncompression OK
1449c609719bSwdenk   -8	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1450c609719bSwdenk    8	common/cmd_bootm.c	Image Type check OK
1451c609719bSwdenk   -9	common/cmd_bootm.c	Unsupported OS (not Linux, BSD, VxWorks, QNX)
1452c609719bSwdenk    9	common/cmd_bootm.c	Start initial ramdisk verification
1453c609719bSwdenk  -10	common/cmd_bootm.c	Ramdisk header has bad	   magic number
1454c609719bSwdenk  -11	common/cmd_bootm.c	Ramdisk header has bad	   checksum
1455c609719bSwdenk   10	common/cmd_bootm.c	Ramdisk header is OK
1456c609719bSwdenk  -12	common/cmd_bootm.c	Ramdisk data   has bad	   checksum
1457c609719bSwdenk   11	common/cmd_bootm.c	Ramdisk data   has correct checksum
1458c609719bSwdenk   12	common/cmd_bootm.c	Ramdisk verification complete, start loading
1459c609719bSwdenk  -13	common/cmd_bootm.c	Wrong Image Type (not PPC Linux Ramdisk)
1460c609719bSwdenk   13	common/cmd_bootm.c	Start multifile image verification
1461c609719bSwdenk   14	common/cmd_bootm.c	No initial ramdisk, no multifile, continue.
1462c609719bSwdenk   15	common/cmd_bootm.c	All preparation done, transferring control to OS
1463c609719bSwdenk
146463e73c9aSwdenk  -30	lib_ppc/board.c		Fatal error, hang the system
146563e73c9aSwdenk  -31	post/post.c		POST test failed, detected by post_output_backlog()
146663e73c9aSwdenk  -32	post/post.c		POST test failed, detected by post_run_single()
146763e73c9aSwdenk
1468c609719bSwdenk   -1	common/cmd_doc.c	Bad usage of "doc" command
1469c609719bSwdenk   -1	common/cmd_doc.c	No boot device
1470c609719bSwdenk   -1	common/cmd_doc.c	Unknown Chip ID on boot device
1471c609719bSwdenk   -1	common/cmd_doc.c	Read Error on boot device
1472c609719bSwdenk   -1	common/cmd_doc.c	Image header has bad magic number
1473c609719bSwdenk
1474c609719bSwdenk   -1	common/cmd_ide.c	Bad usage of "ide" command
1475c609719bSwdenk   -1	common/cmd_ide.c	No boot device
1476c609719bSwdenk   -1	common/cmd_ide.c	Unknown boot device
1477c609719bSwdenk   -1	common/cmd_ide.c	Unknown partition table
1478c609719bSwdenk   -1	common/cmd_ide.c	Invalid partition type
1479c609719bSwdenk   -1	common/cmd_ide.c	Read Error on boot device
1480c609719bSwdenk   -1	common/cmd_ide.c	Image header has bad magic number
1481c609719bSwdenk
1482206c60cbSwdenk   -1	common/cmd_nand.c	Bad usage of "nand" command
1483206c60cbSwdenk   -1	common/cmd_nand.c	No boot device
1484206c60cbSwdenk   -1	common/cmd_nand.c	Unknown Chip ID on boot device
1485206c60cbSwdenk   -1	common/cmd_nand.c	Read Error on boot device
1486206c60cbSwdenk   -1	common/cmd_nand.c	Image header has bad magic number
1487206c60cbSwdenk
1488206c60cbSwdenk   -1	common/env_common.c	Environment has a bad CRC, using default
1489c609719bSwdenk
1490c609719bSwdenk
1491c609719bSwdenkModem Support:
1492c609719bSwdenk--------------
1493c609719bSwdenk
149485ec0bccSwdenk[so far only for SMDK2400 and TRAB boards]
1495c609719bSwdenk
1496c609719bSwdenk- Modem support endable:
1497c609719bSwdenk		CONFIG_MODEM_SUPPORT
1498c609719bSwdenk
1499c609719bSwdenk- RTS/CTS Flow control enable:
1500c609719bSwdenk		CONFIG_HWFLOW
1501c609719bSwdenk
1502c609719bSwdenk- Modem debug support:
1503c609719bSwdenk		CONFIG_MODEM_SUPPORT_DEBUG
1504c609719bSwdenk
1505c609719bSwdenk		Enables debugging stuff (char screen[1024], dbg())
1506c609719bSwdenk		for modem support. Useful only with BDI2000.
1507c609719bSwdenk
1508a8c7c708Swdenk- Interrupt support (PPC):
1509a8c7c708Swdenk
1510a8c7c708Swdenk		There are common interrupt_init() and timer_interrupt()
1511a8c7c708Swdenk		for all PPC archs. interrupt_init() calls interrupt_init_cpu()
1512a8c7c708Swdenk		for cpu specific initialization. interrupt_init_cpu()
1513a8c7c708Swdenk		should set decrementer_count to appropriate value. If
1514a8c7c708Swdenk		cpu resets decrementer automatically after interrupt
1515a8c7c708Swdenk		(ppc4xx) it should set decrementer_count to zero.
1516a8c7c708Swdenk		timer_interrupt() calls timer_interrupt_cpu() for cpu
1517a8c7c708Swdenk		specific handling. If board has watchdog / status_led
1518a8c7c708Swdenk		/ other_activity_monitor it works automatically from
1519a8c7c708Swdenk		general timer_interrupt().
1520a8c7c708Swdenk
1521c609719bSwdenk- General:
1522c609719bSwdenk
1523c609719bSwdenk		In the target system modem support is enabled when a
1524c609719bSwdenk		specific key (key combination) is pressed during
1525c609719bSwdenk		power-on. Otherwise U-Boot will boot normally
1526c609719bSwdenk		(autoboot). The key_pressed() fuction is called from
1527c609719bSwdenk		board_init(). Currently key_pressed() is a dummy
1528c609719bSwdenk		function, returning 1 and thus enabling modem
1529c609719bSwdenk		initialization.
1530c609719bSwdenk
1531c609719bSwdenk		If there are no modem init strings in the
1532c609719bSwdenk		environment, U-Boot proceed to autoboot; the
1533c609719bSwdenk		previous output (banner, info printfs) will be
1534c609719bSwdenk		supressed, though.
1535c609719bSwdenk
1536c609719bSwdenk		See also: doc/README.Modem
1537c609719bSwdenk
1538c609719bSwdenk
1539c609719bSwdenkConfiguration Settings:
1540c609719bSwdenk-----------------------
1541c609719bSwdenk
1542c609719bSwdenk- CFG_LONGHELP: Defined when you want long help messages included;
1543c609719bSwdenk		undefine this when you're short of memory.
1544c609719bSwdenk
1545c609719bSwdenk- CFG_PROMPT:	This is what U-Boot prints on the console to
1546c609719bSwdenk		prompt for user input.
1547c609719bSwdenk
1548c609719bSwdenk- CFG_CBSIZE:	Buffer size for input from the Console
1549c609719bSwdenk
1550c609719bSwdenk- CFG_PBSIZE:	Buffer size for Console output
1551c609719bSwdenk
1552c609719bSwdenk- CFG_MAXARGS:	max. Number of arguments accepted for monitor commands
1553c609719bSwdenk
1554c609719bSwdenk- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1555c609719bSwdenk		the application (usually a Linux kernel) when it is
1556c609719bSwdenk		booted
1557c609719bSwdenk
1558c609719bSwdenk- CFG_BAUDRATE_TABLE:
1559c609719bSwdenk		List of legal baudrate settings for this board.
1560c609719bSwdenk
1561c609719bSwdenk- CFG_CONSOLE_INFO_QUIET
1562c609719bSwdenk		Suppress display of console information at boot.
1563c609719bSwdenk
1564c609719bSwdenk- CFG_CONSOLE_IS_IN_ENV
1565c609719bSwdenk		If the board specific function
1566c609719bSwdenk			extern int overwrite_console (void);
1567c609719bSwdenk		returns 1, the stdin, stderr and stdout are switched to the
1568c609719bSwdenk		serial port, else the settings in the environment are used.
1569c609719bSwdenk
1570c609719bSwdenk- CFG_CONSOLE_OVERWRITE_ROUTINE
1571c609719bSwdenk		Enable the call to overwrite_console().
1572c609719bSwdenk
1573c609719bSwdenk- CFG_CONSOLE_ENV_OVERWRITE
1574c609719bSwdenk		Enable overwrite of previous console environment settings.
1575c609719bSwdenk
1576c609719bSwdenk- CFG_MEMTEST_START, CFG_MEMTEST_END:
1577c609719bSwdenk		Begin and End addresses of the area used by the
1578c609719bSwdenk		simple memory test.
1579c609719bSwdenk
1580c609719bSwdenk- CFG_ALT_MEMTEST:
1581c609719bSwdenk		Enable an alternate, more extensive memory test.
1582c609719bSwdenk
15835f535fe1Swdenk- CFG_MEMTEST_SCRATCH:
15845f535fe1Swdenk		Scratch address used by the alternate memory test
15855f535fe1Swdenk		You only need to set this if address zero isn't writeable
15865f535fe1Swdenk
1587c609719bSwdenk- CFG_TFTP_LOADADDR:
1588c609719bSwdenk		Default load address for network file downloads
1589c609719bSwdenk
1590c609719bSwdenk- CFG_LOADS_BAUD_CHANGE:
1591c609719bSwdenk		Enable temporary baudrate change while serial download
1592c609719bSwdenk
1593c609719bSwdenk- CFG_SDRAM_BASE:
1594c609719bSwdenk		Physical start address of SDRAM. _Must_ be 0 here.
1595c609719bSwdenk
1596c609719bSwdenk- CFG_MBIO_BASE:
1597c609719bSwdenk		Physical start address of Motherboard I/O (if using a
1598c609719bSwdenk		Cogent motherboard)
1599c609719bSwdenk
1600c609719bSwdenk- CFG_FLASH_BASE:
1601c609719bSwdenk		Physical start address of Flash memory.
1602c609719bSwdenk
1603c609719bSwdenk- CFG_MONITOR_BASE:
1604c609719bSwdenk		Physical start address of boot monitor code (set by
1605c609719bSwdenk		make config files to be same as the text base address
1606c609719bSwdenk		(TEXT_BASE) used when linking) - same as
1607c609719bSwdenk		CFG_FLASH_BASE when booting from flash.
1608c609719bSwdenk
1609c609719bSwdenk- CFG_MONITOR_LEN:
16103b57fe0aSwdenk		Size of memory reserved for monitor code, used to
16113b57fe0aSwdenk		determine _at_compile_time_ (!) if the environment is
16123b57fe0aSwdenk		embedded within the U-Boot image, or in a separate
16133b57fe0aSwdenk		flash sector.
1614c609719bSwdenk
1615c609719bSwdenk- CFG_MALLOC_LEN:
1616c609719bSwdenk		Size of DRAM reserved for malloc() use.
1617c609719bSwdenk
1618c609719bSwdenk- CFG_BOOTMAPSZ:
1619c609719bSwdenk		Maximum size of memory mapped by the startup code of
1620c609719bSwdenk		the Linux kernel; all data that must be processed by
1621c609719bSwdenk		the Linux kernel (bd_info, boot arguments, eventually
1622c609719bSwdenk		initrd image) must be put below this limit.
1623c609719bSwdenk
1624c609719bSwdenk- CFG_MAX_FLASH_BANKS:
1625c609719bSwdenk		Max number of Flash memory banks
1626c609719bSwdenk
1627c609719bSwdenk- CFG_MAX_FLASH_SECT:
1628c609719bSwdenk		Max number of sectors on a Flash chip
1629c609719bSwdenk
1630c609719bSwdenk- CFG_FLASH_ERASE_TOUT:
1631c609719bSwdenk		Timeout for Flash erase operations (in ms)
1632c609719bSwdenk
1633c609719bSwdenk- CFG_FLASH_WRITE_TOUT:
1634c609719bSwdenk		Timeout for Flash write operations (in ms)
1635c609719bSwdenk
16368564acf9Swdenk- CFG_FLASH_LOCK_TOUT
16378564acf9Swdenk		Timeout for Flash set sector lock bit operation (in ms)
16388564acf9Swdenk
16398564acf9Swdenk- CFG_FLASH_UNLOCK_TOUT
16408564acf9Swdenk		Timeout for Flash clear lock bits operation (in ms)
16418564acf9Swdenk
16428564acf9Swdenk- CFG_FLASH_PROTECTION
16438564acf9Swdenk		If defined, hardware flash sectors protection is used
16448564acf9Swdenk		instead of U-Boot software protection.
16458564acf9Swdenk
1646c609719bSwdenk- CFG_DIRECT_FLASH_TFTP:
1647c609719bSwdenk
1648c609719bSwdenk		Enable TFTP transfers directly to flash memory;
1649c609719bSwdenk		without this option such a download has to be
1650c609719bSwdenk		performed in two steps: (1) download to RAM, and (2)
1651c609719bSwdenk		copy from RAM to flash.
1652c609719bSwdenk
1653c609719bSwdenk		The two-step approach is usually more reliable, since
1654c609719bSwdenk		you can check if the download worked before you erase
1655c609719bSwdenk		the flash, but in some situations (when sytem RAM is
1656c609719bSwdenk		too limited to allow for a tempory copy of the
1657c609719bSwdenk		downloaded image) this option may be very useful.
1658c609719bSwdenk
1659c609719bSwdenk- CFG_FLASH_CFI:
1660c609719bSwdenk		Define if the flash driver uses extra elements in the
16615653fc33Swdenk		common flash structure for storing flash geometry.
16625653fc33Swdenk
16635653fc33Swdenk- CFG_FLASH_CFI_DRIVER
16645653fc33Swdenk		This option also enables the building of the cfi_flash driver
16655653fc33Swdenk		in the drivers directory
166653cf9435Sstroese
166753cf9435Sstroese- CFG_RX_ETH_BUFFER:
166853cf9435Sstroese		Defines the number of ethernet receive buffers. On some
166953cf9435Sstroese		ethernet controllers it is recommended to set this value
167053cf9435Sstroese		to 8 or even higher (EEPRO100 or 405 EMAC), since all
167153cf9435Sstroese		buffers can be full shortly after enabling the interface
167253cf9435Sstroese		on high ethernet traffic.
167353cf9435Sstroese		Defaults to 4 if not defined.
1674c609719bSwdenk
1675c609719bSwdenkThe following definitions that deal with the placement and management
1676c609719bSwdenkof environment data (variable area); in general, we support the
1677c609719bSwdenkfollowing configurations:
1678c609719bSwdenk
1679c609719bSwdenk- CFG_ENV_IS_IN_FLASH:
1680c609719bSwdenk
1681c609719bSwdenk	Define this if the environment is in flash memory.
1682c609719bSwdenk
1683c609719bSwdenk	a) The environment occupies one whole flash sector, which is
1684c609719bSwdenk	   "embedded" in the text segment with the U-Boot code. This
1685c609719bSwdenk	   happens usually with "bottom boot sector" or "top boot
1686c609719bSwdenk	   sector" type flash chips, which have several smaller
1687c609719bSwdenk	   sectors at the start or the end. For instance, such a
1688c609719bSwdenk	   layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1689c609719bSwdenk	   such a case you would place the environment in one of the
1690c609719bSwdenk	   4 kB sectors - with U-Boot code before and after it. With
1691c609719bSwdenk	   "top boot sector" type flash chips, you would put the
1692c609719bSwdenk	   environment in one of the last sectors, leaving a gap
1693c609719bSwdenk	   between U-Boot and the environment.
1694c609719bSwdenk
1695c609719bSwdenk	- CFG_ENV_OFFSET:
1696c609719bSwdenk
1697c609719bSwdenk	   Offset of environment data (variable area) to the
1698c609719bSwdenk	   beginning of flash memory; for instance, with bottom boot
1699c609719bSwdenk	   type flash chips the second sector can be used: the offset
1700c609719bSwdenk	   for this sector is given here.
1701c609719bSwdenk
1702c609719bSwdenk	   CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1703c609719bSwdenk
1704c609719bSwdenk	- CFG_ENV_ADDR:
1705c609719bSwdenk
1706c609719bSwdenk	   This is just another way to specify the start address of
1707c609719bSwdenk	   the flash sector containing the environment (instead of
1708c609719bSwdenk	   CFG_ENV_OFFSET).
1709c609719bSwdenk
1710c609719bSwdenk	- CFG_ENV_SECT_SIZE:
1711c609719bSwdenk
1712c609719bSwdenk	   Size of the sector containing the environment.
1713c609719bSwdenk
1714c609719bSwdenk
1715c609719bSwdenk	b) Sometimes flash chips have few, equal sized, BIG sectors.
1716c609719bSwdenk	   In such a case you don't want to spend a whole sector for
1717c609719bSwdenk	   the environment.
1718c609719bSwdenk
1719c609719bSwdenk	- CFG_ENV_SIZE:
1720c609719bSwdenk
1721c609719bSwdenk	   If you use this in combination with CFG_ENV_IS_IN_FLASH
1722c609719bSwdenk	   and CFG_ENV_SECT_SIZE, you can specify to use only a part
1723c609719bSwdenk	   of this flash sector for the environment. This saves
1724c609719bSwdenk	   memory for the RAM copy of the environment.
1725c609719bSwdenk
1726c609719bSwdenk	   It may also save flash memory if you decide to use this
1727c609719bSwdenk	   when your environment is "embedded" within U-Boot code,
1728c609719bSwdenk	   since then the remainder of the flash sector could be used
1729c609719bSwdenk	   for U-Boot code. It should be pointed out that this is
1730c609719bSwdenk	   STRONGLY DISCOURAGED from a robustness point of view:
1731c609719bSwdenk	   updating the environment in flash makes it always
1732c609719bSwdenk	   necessary to erase the WHOLE sector. If something goes
1733c609719bSwdenk	   wrong before the contents has been restored from a copy in
1734c609719bSwdenk	   RAM, your target system will be dead.
1735c609719bSwdenk
1736c609719bSwdenk	- CFG_ENV_ADDR_REDUND
1737c609719bSwdenk	  CFG_ENV_SIZE_REDUND
1738c609719bSwdenk
1739c609719bSwdenk	   These settings describe a second storage area used to hold
1740c609719bSwdenk	   a redundand copy of the environment data, so that there is
17413e38691eSwdenk	   a valid backup copy in case there is a power failure during
1742c609719bSwdenk	   a "saveenv" operation.
1743c609719bSwdenk
1744c609719bSwdenkBE CAREFUL! Any changes to the flash layout, and some changes to the
1745c609719bSwdenksource code will make it necessary to adapt <board>/u-boot.lds*
1746c609719bSwdenkaccordingly!
1747c609719bSwdenk
1748c609719bSwdenk
1749c609719bSwdenk- CFG_ENV_IS_IN_NVRAM:
1750c609719bSwdenk
1751c609719bSwdenk	Define this if you have some non-volatile memory device
1752c609719bSwdenk	(NVRAM, battery buffered SRAM) which you want to use for the
1753c609719bSwdenk	environment.
1754c609719bSwdenk
1755c609719bSwdenk	- CFG_ENV_ADDR:
1756c609719bSwdenk	- CFG_ENV_SIZE:
1757c609719bSwdenk
1758c609719bSwdenk	  These two #defines are used to determin the memory area you
1759c609719bSwdenk	  want to use for environment. It is assumed that this memory
1760c609719bSwdenk	  can just be read and written to, without any special
1761c609719bSwdenk	  provision.
1762c609719bSwdenk
1763c609719bSwdenkBE CAREFUL! The first access to the environment happens quite early
1764c609719bSwdenkin U-Boot initalization (when we try to get the setting of for the
1765c609719bSwdenkconsole baudrate). You *MUST* have mappend your NVRAM area then, or
1766c609719bSwdenkU-Boot will hang.
1767c609719bSwdenk
1768c609719bSwdenkPlease note that even with NVRAM we still use a copy of the
1769c609719bSwdenkenvironment in RAM: we could work on NVRAM directly, but we want to
1770c609719bSwdenkkeep settings there always unmodified except somebody uses "saveenv"
1771c609719bSwdenkto save the current settings.
1772c609719bSwdenk
1773c609719bSwdenk
1774c609719bSwdenk- CFG_ENV_IS_IN_EEPROM:
1775c609719bSwdenk
1776c609719bSwdenk	Use this if you have an EEPROM or similar serial access
1777c609719bSwdenk	device and a driver for it.
1778c609719bSwdenk
1779c609719bSwdenk	- CFG_ENV_OFFSET:
1780c609719bSwdenk	- CFG_ENV_SIZE:
1781c609719bSwdenk
1782c609719bSwdenk	  These two #defines specify the offset and size of the
1783c609719bSwdenk	  environment area within the total memory of your EEPROM.
1784c609719bSwdenk
1785c609719bSwdenk	- CFG_I2C_EEPROM_ADDR:
1786c609719bSwdenk	  If defined, specified the chip address of the EEPROM device.
1787c609719bSwdenk	  The default address is zero.
1788c609719bSwdenk
1789c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_BITS:
1790c609719bSwdenk	  If defined, the number of bits used to address bytes in a
1791c609719bSwdenk	  single page in the EEPROM device.  A 64 byte page, for example
1792c609719bSwdenk	  would require six bits.
1793c609719bSwdenk
1794c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1795c609719bSwdenk	  If defined, the number of milliseconds to delay between
1796c609719bSwdenk	  page writes.	The default is zero milliseconds.
1797c609719bSwdenk
1798c609719bSwdenk	- CFG_I2C_EEPROM_ADDR_LEN:
1799c609719bSwdenk	  The length in bytes of the EEPROM memory array address.  Note
1800c609719bSwdenk	  that this is NOT the chip address length!
1801c609719bSwdenk
18025cf91d6bSwdenk	- CFG_I2C_EEPROM_ADDR_OVERFLOW:
18035cf91d6bSwdenk	  EEPROM chips that implement "address overflow" are ones
18045cf91d6bSwdenk	  like Catalyst 24WC04/08/16 which has 9/10/11 bits of
18055cf91d6bSwdenk	  address and the extra bits end up in the "chip address" bit
18065cf91d6bSwdenk	  slots. This makes a 24WC08 (1Kbyte) chip look like four 256
18075cf91d6bSwdenk	  byte chips.
18085cf91d6bSwdenk
18095cf91d6bSwdenk	  Note that we consider the length of the address field to
18105cf91d6bSwdenk	  still be one byte because the extra address bits are hidden
18115cf91d6bSwdenk	  in the chip address.
18125cf91d6bSwdenk
1813c609719bSwdenk	- CFG_EEPROM_SIZE:
1814c609719bSwdenk	  The size in bytes of the EEPROM device.
1815c609719bSwdenk
1816c609719bSwdenk
18175779d8d9Swdenk- CFG_ENV_IS_IN_DATAFLASH:
18185779d8d9Swdenk
18195779d8d9Swdenk	Define this if you have a DataFlash memory device which you
18205779d8d9Swdenk	want to use for the environment.
18215779d8d9Swdenk
18225779d8d9Swdenk	- CFG_ENV_OFFSET:
18235779d8d9Swdenk	- CFG_ENV_ADDR:
18245779d8d9Swdenk	- CFG_ENV_SIZE:
18255779d8d9Swdenk
18265779d8d9Swdenk	  These three #defines specify the offset and size of the
18275779d8d9Swdenk	  environment area within the total memory of your DataFlash placed
18285779d8d9Swdenk	  at the specified address.
18295779d8d9Swdenk
1830*13a5695bSwdenk- CFG_ENV_IS_IN_NAND:
1831*13a5695bSwdenk
1832*13a5695bSwdenk	Define this if you have a NAND device which you want to use
1833*13a5695bSwdenk	for the environment.
1834*13a5695bSwdenk
1835*13a5695bSwdenk	- CFG_ENV_OFFSET:
1836*13a5695bSwdenk	- CFG_ENV_SIZE:
1837*13a5695bSwdenk
1838*13a5695bSwdenk	  These two #defines specify the offset and size of the environment
1839*13a5695bSwdenk	  area within the first NAND device.
18405779d8d9Swdenk
1841c609719bSwdenk- CFG_SPI_INIT_OFFSET
1842c609719bSwdenk
1843c609719bSwdenk	Defines offset to the initial SPI buffer area in DPRAM. The
1844c609719bSwdenk	area is used at an early stage (ROM part) if the environment
1845c609719bSwdenk	is configured to reside in the SPI EEPROM: We need a 520 byte
1846c609719bSwdenk	scratch DPRAM area. It is used between the two initialization
1847c609719bSwdenk	calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1848c609719bSwdenk	to be a good choice since it makes it far enough from the
1849c609719bSwdenk	start of the data area as well as from the stack pointer.
1850c609719bSwdenk
1851c609719bSwdenkPlease note that the environment is read-only as long as the monitor
1852c609719bSwdenkhas been relocated to RAM and a RAM copy of the environment has been
1853c609719bSwdenkcreated; also, when using EEPROM you will have to use getenv_r()
1854c609719bSwdenkuntil then to read environment variables.
1855c609719bSwdenk
185685ec0bccSwdenkThe environment is protected by a CRC32 checksum. Before the monitor
185785ec0bccSwdenkis relocated into RAM, as a result of a bad CRC you will be working
185885ec0bccSwdenkwith the compiled-in default environment - *silently*!!! [This is
185985ec0bccSwdenknecessary, because the first environment variable we need is the
186085ec0bccSwdenk"baudrate" setting for the console - if we have a bad CRC, we don't
186185ec0bccSwdenkhave any device yet where we could complain.]
1862c609719bSwdenk
1863c609719bSwdenkNote: once the monitor has been relocated, then it will complain if
1864c609719bSwdenkthe default environment is used; a new CRC is computed as soon as you
186585ec0bccSwdenkuse the "saveenv" command to store a valid environment.
1866c609719bSwdenk
1867fc3e2165Swdenk- CFG_FAULT_ECHO_LINK_DOWN:
1868fc3e2165Swdenk		Echo the inverted Ethernet link state to the fault LED.
1869fc3e2165Swdenk
1870fc3e2165Swdenk		Note: If this option is active, then CFG_FAULT_MII_ADDR
1871fc3e2165Swdenk		      also needs to be defined.
1872fc3e2165Swdenk
1873fc3e2165Swdenk- CFG_FAULT_MII_ADDR:
1874fc3e2165Swdenk		MII address of the PHY to check for the Ethernet link state.
1875c609719bSwdenk
1876c40b2956Swdenk- CFG_64BIT_VSPRINTF:
1877c40b2956Swdenk		Makes vsprintf (and all *printf functions) support printing
1878c40b2956Swdenk		of 64bit values by using the L quantifier
1879c40b2956Swdenk
1880c40b2956Swdenk- CFG_64BIT_STRTOUL:
1881c40b2956Swdenk		Adds simple_strtoull that returns a 64bit value
1882c40b2956Swdenk
1883c609719bSwdenkLow Level (hardware related) configuration options:
1884dc7c9a1aSwdenk---------------------------------------------------
1885c609719bSwdenk
1886c609719bSwdenk- CFG_CACHELINE_SIZE:
1887c609719bSwdenk		Cache Line Size of the CPU.
1888c609719bSwdenk
1889c609719bSwdenk- CFG_DEFAULT_IMMR:
1890c609719bSwdenk		Default address of the IMMR after system reset.
18912535d602Swdenk
18922535d602Swdenk		Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
18932535d602Swdenk		and RPXsuper) to be able to adjust the position of
18942535d602Swdenk		the IMMR register after a reset.
1895c609719bSwdenk
18967f6c2cbcSwdenk- Floppy Disk Support:
18977f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER
18987f6c2cbcSwdenk
18997f6c2cbcSwdenk		the default drive number (default value 0)
19007f6c2cbcSwdenk
19017f6c2cbcSwdenk		CFG_ISA_IO_STRIDE
19027f6c2cbcSwdenk
19037f6c2cbcSwdenk		defines the spacing between fdc chipset registers
19047f6c2cbcSwdenk		(default value 1)
19057f6c2cbcSwdenk
19067f6c2cbcSwdenk		CFG_ISA_IO_OFFSET
19077f6c2cbcSwdenk
19087f6c2cbcSwdenk		defines the offset of register from address. It
19097f6c2cbcSwdenk		depends on which part of the data bus is connected to
19107f6c2cbcSwdenk		the fdc chipset. (default value 0)
19117f6c2cbcSwdenk
19127f6c2cbcSwdenk		If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
19137f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER are undefined, they take their
19147f6c2cbcSwdenk		default value.
19157f6c2cbcSwdenk
19167f6c2cbcSwdenk		if CFG_FDC_HW_INIT is defined, then the function
19177f6c2cbcSwdenk		fdc_hw_init() is called at the beginning of the FDC
19187f6c2cbcSwdenk		setup. fdc_hw_init() must be provided by the board
19197f6c2cbcSwdenk		source code. It is used to make hardware dependant
19207f6c2cbcSwdenk		initializations.
19217f6c2cbcSwdenk
1922c609719bSwdenk- CFG_IMMR:	Physical address of the Internal Memory Mapped
1923c609719bSwdenk		Register; DO NOT CHANGE! (11-4)
1924c609719bSwdenk		[MPC8xx systems only]
1925c609719bSwdenk
1926c609719bSwdenk- CFG_INIT_RAM_ADDR:
1927c609719bSwdenk
19287152b1d0Swdenk		Start address of memory area that can be used for
1929c609719bSwdenk		initial data and stack; please note that this must be
1930c609719bSwdenk		writable memory that is working WITHOUT special
1931c609719bSwdenk		initialization, i. e. you CANNOT use normal RAM which
1932c609719bSwdenk		will become available only after programming the
1933c609719bSwdenk		memory controller and running certain initialization
1934c609719bSwdenk		sequences.
1935c609719bSwdenk
1936c609719bSwdenk		U-Boot uses the following memory types:
1937c609719bSwdenk		- MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1938c609719bSwdenk		- MPC824X: data cache
1939c609719bSwdenk		- PPC4xx:  data cache
1940c609719bSwdenk
194185ec0bccSwdenk- CFG_GBL_DATA_OFFSET:
1942c609719bSwdenk
1943c609719bSwdenk		Offset of the initial data structure in the memory
1944c609719bSwdenk		area defined by CFG_INIT_RAM_ADDR. Usually
194585ec0bccSwdenk		CFG_GBL_DATA_OFFSET is chosen such that the initial
1946c609719bSwdenk		data is located at the end of the available space
1947c609719bSwdenk		(sometimes written as (CFG_INIT_RAM_END -
1948c609719bSwdenk		CFG_INIT_DATA_SIZE), and the initial stack is just
1949c609719bSwdenk		below that area (growing from (CFG_INIT_RAM_ADDR +
195085ec0bccSwdenk		CFG_GBL_DATA_OFFSET) downward.
1951c609719bSwdenk
1952c609719bSwdenk	Note:
1953c609719bSwdenk		On the MPC824X (or other systems that use the data
1954c609719bSwdenk		cache for initial memory) the address chosen for
1955c609719bSwdenk		CFG_INIT_RAM_ADDR is basically arbitrary - it must
1956c609719bSwdenk		point to an otherwise UNUSED address space between
1957c609719bSwdenk		the top of RAM and the start of the PCI space.
1958c609719bSwdenk
1959c609719bSwdenk- CFG_SIUMCR:	SIU Module Configuration (11-6)
1960c609719bSwdenk
1961c609719bSwdenk- CFG_SYPCR:	System Protection Control (11-9)
1962c609719bSwdenk
1963c609719bSwdenk- CFG_TBSCR:	Time Base Status and Control (11-26)
1964c609719bSwdenk
1965c609719bSwdenk- CFG_PISCR:	Periodic Interrupt Status and Control (11-31)
1966c609719bSwdenk
1967c609719bSwdenk- CFG_PLPRCR:	PLL, Low-Power, and Reset Control Register (15-30)
1968c609719bSwdenk
1969c609719bSwdenk- CFG_SCCR:	System Clock and reset Control Register (15-27)
1970c609719bSwdenk
1971c609719bSwdenk- CFG_OR_TIMING_SDRAM:
1972c609719bSwdenk		SDRAM timing
1973c609719bSwdenk
1974c609719bSwdenk- CFG_MAMR_PTA:
1975c609719bSwdenk		periodic timer for refresh
1976c609719bSwdenk
1977c609719bSwdenk- CFG_DER:	Debug Event Register (37-47)
1978c609719bSwdenk
1979c609719bSwdenk- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1980c609719bSwdenk  CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1981c609719bSwdenk  CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1982c609719bSwdenk  CFG_BR1_PRELIM:
1983c609719bSwdenk		Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1984c609719bSwdenk
1985c609719bSwdenk- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1986c609719bSwdenk  CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1987c609719bSwdenk  CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1988c609719bSwdenk		Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1989c609719bSwdenk
1990c609719bSwdenk- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1991c609719bSwdenk  CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1992c609719bSwdenk		Machine Mode Register and Memory Periodic Timer
1993c609719bSwdenk		Prescaler definitions (SDRAM timing)
1994c609719bSwdenk
1995c609719bSwdenk- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1996c609719bSwdenk		enable I2C microcode relocation patch (MPC8xx);
1997c609719bSwdenk		define relocation offset in DPRAM [DSP2]
1998c609719bSwdenk
1999c609719bSwdenk- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
2000c609719bSwdenk		enable SPI microcode relocation patch (MPC8xx);
2001c609719bSwdenk		define relocation offset in DPRAM [SCC4]
2002c609719bSwdenk
2003c609719bSwdenk- CFG_USE_OSCCLK:
2004c609719bSwdenk		Use OSCM clock mode on MBX8xx board. Be careful,
2005c609719bSwdenk		wrong setting might damage your board. Read
2006c609719bSwdenk		doc/README.MBX before setting this variable!
2007c609719bSwdenk
2008ea909b76Swdenk- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2009ea909b76Swdenk		Offset of the bootmode word in DPRAM used by post
2010ea909b76Swdenk		(Power On Self Tests). This definition overrides
2011ea909b76Swdenk		#define'd default value in commproc.h resp.
2012ea909b76Swdenk		cpm_8260.h.
2013ea909b76Swdenk
20145d232d0eSwdenk- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
20155d232d0eSwdenk  CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
20165d232d0eSwdenk  CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
20175d232d0eSwdenk  CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
20185d232d0eSwdenk  CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
20195d232d0eSwdenk  CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
20205d232d0eSwdenk  CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
20215d232d0eSwdenk  CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
20225d232d0eSwdenk		Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
20235d232d0eSwdenk
2024c26e454dSwdenk- CONFIG_ETHER_ON_FEC[12]
2025c26e454dSwdenk		Define to enable FEC[12] on a 8xx series processor.
2026c26e454dSwdenk
2027c26e454dSwdenk- CONFIG_FEC[12]_PHY
2028c26e454dSwdenk		Define to the hardcoded PHY address which corresponds
20296e592385Swdenk		to the given FEC; i. e.
2030c26e454dSwdenk			#define CONFIG_FEC1_PHY 4
2031c26e454dSwdenk		means that the PHY with address 4 is connected to FEC1
2032c26e454dSwdenk
2033c26e454dSwdenk		When set to -1, means to probe for first available.
2034c26e454dSwdenk
2035c26e454dSwdenk- CONFIG_FEC[12]_PHY_NORXERR
2036c26e454dSwdenk		The PHY does not have a RXERR line (RMII only).
2037c26e454dSwdenk		(so program the FEC to ignore it).
2038c26e454dSwdenk
2039c26e454dSwdenk- CONFIG_RMII
2040c26e454dSwdenk		Enable RMII mode for all FECs.
2041c26e454dSwdenk		Note that this is a global option, we can't
2042c26e454dSwdenk		have one FEC in standard MII mode and another in RMII mode.
2043c26e454dSwdenk
20445cf91d6bSwdenk- CONFIG_CRC32_VERIFY
20455cf91d6bSwdenk		Add a verify option to the crc32 command.
20465cf91d6bSwdenk		The syntax is:
20475cf91d6bSwdenk
20485cf91d6bSwdenk		=> crc32 -v <address> <count> <crc32>
20495cf91d6bSwdenk
20505cf91d6bSwdenk		Where address/count indicate a memory area
20515cf91d6bSwdenk		and crc32 is the correct crc32 which the
20525cf91d6bSwdenk		area should have.
20535cf91d6bSwdenk
2054c609719bSwdenkBuilding the Software:
2055c609719bSwdenk======================
2056c609719bSwdenk
2057c609719bSwdenkBuilding U-Boot has been tested in native PPC environments (on a
2058c609719bSwdenkPowerBook G3 running LinuxPPC 2000) and in cross environments
2059c609719bSwdenk(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
2060c609719bSwdenkNetBSD 1.5 on x86).
2061c609719bSwdenk
2062c609719bSwdenkIf you are not using a native PPC environment, it is assumed that you
2063c609719bSwdenkhave the GNU cross compiling tools available in your path and named
2064c609719bSwdenkwith a prefix of "powerpc-linux-". If this is not the case, (e.g. if
2065c609719bSwdenkyou are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
2066c609719bSwdenkthe definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
2067c609719bSwdenkchange it to:
2068c609719bSwdenk
2069c609719bSwdenk	CROSS_COMPILE = ppc_4xx-
2070c609719bSwdenk
2071c609719bSwdenk
2072c609719bSwdenkU-Boot is intended to be  simple  to  build.  After  installing	 the
2073c609719bSwdenksources	 you must configure U-Boot for one specific board type. This
2074c609719bSwdenkis done by typing:
2075c609719bSwdenk
2076c609719bSwdenk	make NAME_config
2077c609719bSwdenk
2078c609719bSwdenkwhere "NAME_config" is the name of one of the existing
2079c609719bSwdenkconfigurations; the following names are supported:
2080c609719bSwdenk
20811eaeb58eSwdenk	ADCIOP_config		FPS860L_config		omap730p2_config
20821eaeb58eSwdenk	ADS860_config		GEN860T_config		pcu_e_config
20831eaeb58eSwdenk	AR405_config		GENIETV_config		PIP405_config
20841eaeb58eSwdenk	at91rm9200dk_config	GTH_config		QS823_config
20851eaeb58eSwdenk	CANBT_config		hermes_config		QS850_config
20861eaeb58eSwdenk	cmi_mpc5xx_config	hymod_config		QS860T_config
20871eaeb58eSwdenk	cogent_common_config	IP860_config		RPXlite_config
20881eaeb58eSwdenk	cogent_mpc8260_config	IVML24_config		RPXsuper_config
20891eaeb58eSwdenk	cogent_mpc8xx_config	IVMS8_config		rsdproto_config
20901eaeb58eSwdenk	CPCI405_config		JSE_config		Sandpoint8240_config
20911eaeb58eSwdenk	CPCIISER4_config	LANTEC_config		sbc8260_config
20921eaeb58eSwdenk	csb272_config		lwmon_config		SM850_config
20931eaeb58eSwdenk	CU824_config		MBX860T_config		SPD823TS_config
20941eaeb58eSwdenk	DUET_ADS_config		MBX_config		stxgp3_config
20951eaeb58eSwdenk	EBONY_config		MPC8260ADS_config	SXNI855T_config
20961eaeb58eSwdenk	ELPT860_config		MPC8540ADS_config	TQM823L_config
20971eaeb58eSwdenk	ESTEEM192E_config	MPC8560ADS_config	TQM850L_config
20981eaeb58eSwdenk	ETX094_config		NETVIA_config		TQM855L_config
20991eaeb58eSwdenk	FADS823_config		omap1510inn_config	TQM860L_config
21001eaeb58eSwdenk	FADS850SAR_config	omap1610h2_config	WALNUT405_config
21011eaeb58eSwdenk	FADS860T_config		omap1610inn_config	ZPC1900_config
21021eaeb58eSwdenk	FPS850L_config		omap5912osk_config
210354387ac9Swdenk
2104c609719bSwdenkNote: for some board special configuration names may exist; check if
2105c609719bSwdenk      additional information is available from the board vendor; for
21062729af9dSwdenk      instance, the TQM823L systems are available without (standard)
21072729af9dSwdenk      or with LCD support. You can select such additional "features"
2108c609719bSwdenk      when chosing the configuration, i. e.
2109c609719bSwdenk
21102729af9dSwdenk      make TQM823L_config
21112729af9dSwdenk	- will configure for a plain TQM823L, i. e. no LCD support
2112c609719bSwdenk
2113c609719bSwdenk      make TQM823L_LCD_config
2114c609719bSwdenk	- will configure for a TQM823L with U-Boot console on LCD
2115c609719bSwdenk
2116c609719bSwdenk      etc.
2117c609719bSwdenk
2118c609719bSwdenk
2119c609719bSwdenkFinally, type "make all", and you should get some working U-Boot
21207152b1d0Swdenkimages ready for download to / installation on your system:
2121c609719bSwdenk
2122c609719bSwdenk- "u-boot.bin" is a raw binary image
2123c609719bSwdenk- "u-boot" is an image in ELF binary format
2124c609719bSwdenk- "u-boot.srec" is in Motorola S-Record format
2125c609719bSwdenk
2126c609719bSwdenk
2127c609719bSwdenkPlease be aware that the Makefiles assume you are using GNU make, so
2128c609719bSwdenkfor instance on NetBSD you might need to use "gmake" instead of
2129c609719bSwdenknative "make".
2130c609719bSwdenk
2131c609719bSwdenk
2132c609719bSwdenkIf the system board that you have is not listed, then you will need
2133c609719bSwdenkto port U-Boot to your hardware platform. To do this, follow these
2134c609719bSwdenksteps:
2135c609719bSwdenk
2136c609719bSwdenk1.  Add a new configuration option for your board to the toplevel
213785ec0bccSwdenk    "Makefile" and to the "MAKEALL" script, using the existing
213885ec0bccSwdenk    entries as examples. Note that here and at many other places
21397152b1d0Swdenk    boards and other names are listed in alphabetical sort order. Please
214085ec0bccSwdenk    keep this order.
2141c609719bSwdenk2.  Create a new directory to hold your board specific code. Add any
214285ec0bccSwdenk    files you need. In your board directory, you will need at least
214385ec0bccSwdenk    the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
214485ec0bccSwdenk3.  Create a new configuration file "include/configs/<board>.h" for
214585ec0bccSwdenk    your board
2146c609719bSwdenk3.  If you're porting U-Boot to a new CPU, then also create a new
2147c609719bSwdenk    directory to hold your CPU specific code. Add any files you need.
214885ec0bccSwdenk4.  Run "make <board>_config" with your new name.
2149c609719bSwdenk5.  Type "make", and you should get a working "u-boot.srec" file
2150c609719bSwdenk    to be installed on your target system.
215185ec0bccSwdenk6.  Debug and solve any problems that might arise.
2152c609719bSwdenk    [Of course, this last step is much harder than it sounds.]
2153c609719bSwdenk
2154c609719bSwdenk
2155c609719bSwdenkTesting of U-Boot Modifications, Ports to New Hardware, etc.:
2156c609719bSwdenk==============================================================
2157c609719bSwdenk
2158c609719bSwdenkIf you have modified U-Boot sources (for instance added a new	board
2159c609719bSwdenkor  support  for  new  devices,	 a new CPU, etc.) you are expected to
2160c609719bSwdenkprovide feedback to the other developers. The feedback normally takes
2161c609719bSwdenkthe form of a "patch", i. e. a context diff against a certain (latest
2162c609719bSwdenkofficial or latest in CVS) version of U-Boot sources.
2163c609719bSwdenk
2164c609719bSwdenkBut before you submit such a patch, please verify that	your  modifi-
2165c609719bSwdenkcation	did not break existing code. At least make sure that *ALL* of
2166c609719bSwdenkthe supported boards compile WITHOUT ANY compiler warnings. To do so,
2167c609719bSwdenkjust run the "MAKEALL" script, which will configure and build U-Boot
2168c609719bSwdenkfor ALL supported system. Be warned, this will take a while. You  can
21697152b1d0Swdenkselect	which  (cross)	compiler  to use by passing a `CROSS_COMPILE'
2170c609719bSwdenkenvironment variable to the script, i. e. to use the cross tools from
2171c609719bSwdenkMontaVista's Hard Hat Linux you can type
2172c609719bSwdenk
2173c609719bSwdenk	CROSS_COMPILE=ppc_8xx- MAKEALL
2174c609719bSwdenk
2175c609719bSwdenkor to build on a native PowerPC system you can type
2176c609719bSwdenk
2177c609719bSwdenk	CROSS_COMPILE=' ' MAKEALL
2178c609719bSwdenk
2179c609719bSwdenkSee also "U-Boot Porting Guide" below.
2180c609719bSwdenk
2181c609719bSwdenk
2182c609719bSwdenkMonitor Commands - Overview:
2183c609719bSwdenk============================
2184c609719bSwdenk
2185c609719bSwdenkgo	- start application at address 'addr'
2186c609719bSwdenkrun	- run commands in an environment variable
2187c609719bSwdenkbootm	- boot application image from memory
2188c609719bSwdenkbootp	- boot image via network using BootP/TFTP protocol
2189c609719bSwdenktftpboot- boot image via network using TFTP protocol
2190c609719bSwdenk	       and env variables "ipaddr" and "serverip"
2191c609719bSwdenk	       (and eventually "gatewayip")
2192c609719bSwdenkrarpboot- boot image via network using RARP/TFTP protocol
2193c609719bSwdenkdiskboot- boot from IDE devicebootd   - boot default, i.e., run 'bootcmd'
2194c609719bSwdenkloads	- load S-Record file over serial line
2195c609719bSwdenkloadb	- load binary file over serial line (kermit mode)
2196c609719bSwdenkmd	- memory display
2197c609719bSwdenkmm	- memory modify (auto-incrementing)
2198c609719bSwdenknm	- memory modify (constant address)
2199c609719bSwdenkmw	- memory write (fill)
2200c609719bSwdenkcp	- memory copy
2201c609719bSwdenkcmp	- memory compare
2202c609719bSwdenkcrc32	- checksum calculation
2203c609719bSwdenkimd	- i2c memory display
2204c609719bSwdenkimm	- i2c memory modify (auto-incrementing)
2205c609719bSwdenkinm	- i2c memory modify (constant address)
2206c609719bSwdenkimw	- i2c memory write (fill)
2207c609719bSwdenkicrc32	- i2c checksum calculation
2208c609719bSwdenkiprobe	- probe to discover valid I2C chip addresses
2209c609719bSwdenkiloop	- infinite loop on address range
2210c609719bSwdenkisdram	- print SDRAM configuration information
2211c609719bSwdenksspi	- SPI utility commands
2212c609719bSwdenkbase	- print or set address offset
2213c609719bSwdenkprintenv- print environment variables
2214c609719bSwdenksetenv	- set environment variables
2215c609719bSwdenksaveenv - save environment variables to persistent storage
2216c609719bSwdenkprotect - enable or disable FLASH write protection
2217c609719bSwdenkerase	- erase FLASH memory
2218c609719bSwdenkflinfo	- print FLASH memory information
2219c609719bSwdenkbdinfo	- print Board Info structure
2220c609719bSwdenkiminfo	- print header information for application image
2221c609719bSwdenkconinfo - print console devices and informations
2222c609719bSwdenkide	- IDE sub-system
2223c609719bSwdenkloop	- infinite loop on address range
2224c609719bSwdenkmtest	- simple RAM test
2225c609719bSwdenkicache	- enable or disable instruction cache
2226c609719bSwdenkdcache	- enable or disable data cache
2227c609719bSwdenkreset	- Perform RESET of the CPU
2228c609719bSwdenkecho	- echo args to console
2229c609719bSwdenkversion - print monitor version
2230c609719bSwdenkhelp	- print online help
2231c609719bSwdenk?	- alias for 'help'
2232c609719bSwdenk
2233c609719bSwdenk
2234c609719bSwdenkMonitor Commands - Detailed Description:
2235c609719bSwdenk========================================
2236c609719bSwdenk
2237c609719bSwdenkTODO.
2238c609719bSwdenk
2239c609719bSwdenkFor now: just type "help <command>".
2240c609719bSwdenk
2241c609719bSwdenk
2242c609719bSwdenkEnvironment Variables:
2243c609719bSwdenk======================
2244c609719bSwdenk
2245c609719bSwdenkU-Boot supports user configuration using Environment Variables which
2246c609719bSwdenkcan be made persistent by saving to Flash memory.
2247c609719bSwdenk
2248c609719bSwdenkEnvironment Variables are set using "setenv", printed using
2249c609719bSwdenk"printenv", and saved to Flash using "saveenv". Using "setenv"
2250c609719bSwdenkwithout a value can be used to delete a variable from the
2251c609719bSwdenkenvironment. As long as you don't save the environment you are
2252c609719bSwdenkworking with an in-memory copy. In case the Flash area containing the
2253c609719bSwdenkenvironment is erased by accident, a default environment is provided.
2254c609719bSwdenk
2255c609719bSwdenkSome configuration options can be set using Environment Variables:
2256c609719bSwdenk
2257c609719bSwdenk  baudrate	- see CONFIG_BAUDRATE
2258c609719bSwdenk
2259c609719bSwdenk  bootdelay	- see CONFIG_BOOTDELAY
2260c609719bSwdenk
2261c609719bSwdenk  bootcmd	- see CONFIG_BOOTCOMMAND
2262c609719bSwdenk
2263c609719bSwdenk  bootargs	- Boot arguments when booting an RTOS image
2264c609719bSwdenk
2265c609719bSwdenk  bootfile	- Name of the image to load with TFTP
2266c609719bSwdenk
2267c609719bSwdenk  autoload	- if set to "no" (any string beginning with 'n'),
2268c609719bSwdenk		  "bootp" will just load perform a lookup of the
2269c609719bSwdenk		  configuration from the BOOTP server, but not try to
2270c609719bSwdenk		  load any image using TFTP
2271c609719bSwdenk
2272c609719bSwdenk  autostart	- if set to "yes", an image loaded using the "bootp",
2273c609719bSwdenk		  "rarpboot", "tftpboot" or "diskboot" commands will
2274c609719bSwdenk		  be automatically started (by internally calling
2275c609719bSwdenk		  "bootm")
2276c609719bSwdenk
22774a6fd34bSwdenk		  If set to "no", a standalone image passed to the
22784a6fd34bSwdenk		  "bootm" command will be copied to the load address
22794a6fd34bSwdenk		  (and eventually uncompressed), but NOT be started.
22804a6fd34bSwdenk		  This can be used to load and uncompress arbitrary
22814a6fd34bSwdenk		  data.
22824a6fd34bSwdenk
228317ea1177Swdenk  i2cfast	- (PPC405GP|PPC405EP only)
228417ea1177Swdenk		  if set to 'y' configures Linux I2C driver for fast
228517ea1177Swdenk		  mode (400kHZ). This environment variable is used in
228617ea1177Swdenk		  initialization code. So, for changes to be effective
228717ea1177Swdenk		  it must be saved and board must be reset.
228817ea1177Swdenk
2289c609719bSwdenk  initrd_high	- restrict positioning of initrd images:
2290c609719bSwdenk		  If this variable is not set, initrd images will be
2291c609719bSwdenk		  copied to the highest possible address in RAM; this
2292c609719bSwdenk		  is usually what you want since it allows for
2293c609719bSwdenk		  maximum initrd size. If for some reason you want to
2294c609719bSwdenk		  make sure that the initrd image is loaded below the
2295c609719bSwdenk		  CFG_BOOTMAPSZ limit, you can set this environment
2296c609719bSwdenk		  variable to a value of "no" or "off" or "0".
2297c609719bSwdenk		  Alternatively, you can set it to a maximum upper
2298c609719bSwdenk		  address to use (U-Boot will still check that it
2299c609719bSwdenk		  does not overwrite the U-Boot stack and data).
2300c609719bSwdenk
2301c609719bSwdenk		  For instance, when you have a system with 16 MB
23027152b1d0Swdenk		  RAM, and want to reserve 4 MB from use by Linux,
2303c609719bSwdenk		  you can do this by adding "mem=12M" to the value of
2304c609719bSwdenk		  the "bootargs" variable. However, now you must make
23057152b1d0Swdenk		  sure that the initrd image is placed in the first
2306c609719bSwdenk		  12 MB as well - this can be done with
2307c609719bSwdenk
2308c609719bSwdenk		  setenv initrd_high 00c00000
2309c609719bSwdenk
231038b99261Swdenk		  If you set initrd_high to 0xFFFFFFFF, this is an
231138b99261Swdenk		  indication to U-Boot that all addresses are legal
231238b99261Swdenk		  for the Linux kernel, including addresses in flash
231338b99261Swdenk		  memory. In this case U-Boot will NOT COPY the
231438b99261Swdenk		  ramdisk at all. This may be useful to reduce the
231538b99261Swdenk		  boot time on your system, but requires that this
231638b99261Swdenk		  feature is supported by your Linux kernel.
231738b99261Swdenk
2318c609719bSwdenk  ipaddr	- IP address; needed for tftpboot command
2319c609719bSwdenk
2320c609719bSwdenk  loadaddr	- Default load address for commands like "bootp",
2321dc7c9a1aSwdenk		  "rarpboot", "tftpboot", "loadb" or "diskboot"
2322c609719bSwdenk
2323c609719bSwdenk  loads_echo	- see CONFIG_LOADS_ECHO
2324c609719bSwdenk
2325c609719bSwdenk  serverip	- TFTP server IP address; needed for tftpboot command
2326c609719bSwdenk
2327c609719bSwdenk  bootretry	- see CONFIG_BOOT_RETRY_TIME
2328c609719bSwdenk
2329c609719bSwdenk  bootdelaykey	- see CONFIG_AUTOBOOT_DELAY_STR
2330c609719bSwdenk
2331c609719bSwdenk  bootstopkey	- see CONFIG_AUTOBOOT_STOP_STR
2332c609719bSwdenk
2333a3d991bdSwdenk  ethprime	- When CONFIG_NET_MULTI is enabled controls which
2334a3d991bdSwdenk		  interface is used first.
2335a3d991bdSwdenk
2336a3d991bdSwdenk  ethact	- When CONFIG_NET_MULTI is enabled controls which
2337a3d991bdSwdenk		  interface is currently active. For example you
2338a3d991bdSwdenk		  can do the following
2339a3d991bdSwdenk
2340a3d991bdSwdenk		  => setenv ethact FEC ETHERNET
2341a3d991bdSwdenk		  => ping 192.168.0.1 # traffic sent on FEC ETHERNET
2342a3d991bdSwdenk		  => setenv ethact SCC ETHERNET
2343a3d991bdSwdenk		  => ping 10.0.0.1 # traffic sent on SCC ETHERNET
2344a3d991bdSwdenk
2345a3d991bdSwdenk   netretry	- When set to "no" each network operation will
2346a3d991bdSwdenk		  either succeed or fail without retrying.
23476e592385Swdenk		  When set to "once" the network operation will
23486e592385Swdenk		  fail when all the available network interfaces
23496e592385Swdenk		  are tried once without success.
2350a3d991bdSwdenk		  Useful on scripts which control the retry operation
2351a3d991bdSwdenk		  themselves.
2352a3d991bdSwdenk
2353a3d991bdSwdenk   vlan		- When set to a value < 4095 the traffic over
2354a3d991bdSwdenk		  ethernet is encapsulated/received over 802.1q
2355a3d991bdSwdenk		  VLAN tagged frames.
2356c609719bSwdenk
2357c609719bSwdenkThe following environment variables may be used and automatically
2358c609719bSwdenkupdated by the network boot commands ("bootp" and "rarpboot"),
2359c609719bSwdenkdepending the information provided by your boot server:
2360c609719bSwdenk
2361c609719bSwdenk  bootfile	- see above
2362c609719bSwdenk  dnsip		- IP address of your Domain Name Server
2363fe389a82Sstroese  dnsip2	- IP address of your secondary Domain Name Server
2364c609719bSwdenk  gatewayip	- IP address of the Gateway (Router) to use
2365c609719bSwdenk  hostname	- Target hostname
2366c609719bSwdenk  ipaddr	- see above
2367c609719bSwdenk  netmask	- Subnet Mask
2368c609719bSwdenk  rootpath	- Pathname of the root filesystem on the NFS server
2369c609719bSwdenk  serverip	- see above
2370c609719bSwdenk
2371c609719bSwdenk
2372c609719bSwdenkThere are two special Environment Variables:
2373c609719bSwdenk
2374c609719bSwdenk  serial#	- contains hardware identification information such
2375c609719bSwdenk		  as type string and/or serial number
2376c609719bSwdenk  ethaddr	- Ethernet address
2377c609719bSwdenk
2378c609719bSwdenkThese variables can be set only once (usually during manufacturing of
2379c609719bSwdenkthe board). U-Boot refuses to delete or overwrite these variables
2380c609719bSwdenkonce they have been set once.
2381c609719bSwdenk
2382c609719bSwdenk
2383c1551ea8SstroeseFurther special Environment Variables:
2384c1551ea8Sstroese
2385c1551ea8Sstroese  ver		- Contains the U-Boot version string as printed
2386c1551ea8Sstroese		  with the "version" command. This variable is
2387c1551ea8Sstroese		  readonly (see CONFIG_VERSION_VARIABLE).
2388c1551ea8Sstroese
2389c1551ea8Sstroese
2390c609719bSwdenkPlease note that changes to some configuration parameters may take
2391c609719bSwdenkonly effect after the next boot (yes, that's just like Windoze :-).
2392c609719bSwdenk
2393c609719bSwdenk
2394f07771ccSwdenkCommand Line Parsing:
2395f07771ccSwdenk=====================
2396f07771ccSwdenk
2397f07771ccSwdenkThere are two different command line parsers available with U-Boot:
23987152b1d0Swdenkthe old "simple" one, and the much more powerful "hush" shell:
2399f07771ccSwdenk
2400f07771ccSwdenkOld, simple command line parser:
2401f07771ccSwdenk--------------------------------
2402f07771ccSwdenk
2403f07771ccSwdenk- supports environment variables (through setenv / saveenv commands)
2404f07771ccSwdenk- several commands on one line, separated by ';'
2405f07771ccSwdenk- variable substitution using "... $(name) ..." syntax
2406f07771ccSwdenk- special characters ('$', ';') can be escaped by prefixing with '\',
2407f07771ccSwdenk  for example:
2408f07771ccSwdenk	setenv bootcmd bootm \$(address)
2409f07771ccSwdenk- You can also escape text by enclosing in single apostrophes, for example:
2410f07771ccSwdenk	setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2411f07771ccSwdenk
2412f07771ccSwdenkHush shell:
2413f07771ccSwdenk-----------
2414f07771ccSwdenk
2415f07771ccSwdenk- similar to Bourne shell, with control structures like
2416f07771ccSwdenk  if...then...else...fi, for...do...done; while...do...done,
2417f07771ccSwdenk  until...do...done, ...
2418f07771ccSwdenk- supports environment ("global") variables (through setenv / saveenv
2419f07771ccSwdenk  commands) and local shell variables (through standard shell syntax
2420f07771ccSwdenk  "name=value"); only environment variables can be used with "run"
2421f07771ccSwdenk  command
2422f07771ccSwdenk
2423f07771ccSwdenkGeneral rules:
2424f07771ccSwdenk--------------
2425f07771ccSwdenk
2426f07771ccSwdenk(1) If a command line (or an environment variable executed by a "run"
2427f07771ccSwdenk    command) contains several commands separated by semicolon, and
2428f07771ccSwdenk    one of these commands fails, then the remaining commands will be
2429f07771ccSwdenk    executed anyway.
2430f07771ccSwdenk
2431f07771ccSwdenk(2) If you execute several variables with one call to run (i. e.
2432f07771ccSwdenk    calling run with a list af variables as arguments), any failing
2433f07771ccSwdenk    command will cause "run" to terminate, i. e. the remaining
2434f07771ccSwdenk    variables are not executed.
2435f07771ccSwdenk
2436c609719bSwdenkNote for Redundant Ethernet Interfaces:
2437c609719bSwdenk=======================================
2438c609719bSwdenk
24397152b1d0SwdenkSome boards come with redundant ethernet interfaces; U-Boot supports
2440c609719bSwdenksuch configurations and is capable of automatic selection of a
24417152b1d0Swdenk"working" interface when needed. MAC assignment works as follows:
2442c609719bSwdenk
2443c609719bSwdenkNetwork interfaces are numbered eth0, eth1, eth2, ... Corresponding
2444c609719bSwdenkMAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2445c609719bSwdenk"eth1addr" (=>eth1), "eth2addr", ...
2446c609719bSwdenk
2447c609719bSwdenkIf the network interface stores some valid MAC address (for instance
2448c609719bSwdenkin SROM), this is used as default address if there is NO correspon-
2449c609719bSwdenkding setting in the environment; if the corresponding environment
2450c609719bSwdenkvariable is set, this overrides the settings in the card; that means:
2451c609719bSwdenk
2452c609719bSwdenko If the SROM has a valid MAC address, and there is no address in the
2453c609719bSwdenk  environment, the SROM's address is used.
2454c609719bSwdenk
2455c609719bSwdenko If there is no valid address in the SROM, and a definition in the
2456c609719bSwdenk  environment exists, then the value from the environment variable is
2457c609719bSwdenk  used.
2458c609719bSwdenk
2459c609719bSwdenko If both the SROM and the environment contain a MAC address, and
2460c609719bSwdenk  both addresses are the same, this MAC address is used.
2461c609719bSwdenk
2462c609719bSwdenko If both the SROM and the environment contain a MAC address, and the
2463c609719bSwdenk  addresses differ, the value from the environment is used and a
2464c609719bSwdenk  warning is printed.
2465c609719bSwdenk
2466c609719bSwdenko If neither SROM nor the environment contain a MAC address, an error
2467c609719bSwdenk  is raised.
2468c609719bSwdenk
2469c609719bSwdenk
2470c609719bSwdenkImage Formats:
2471c609719bSwdenk==============
2472c609719bSwdenk
2473c609719bSwdenkThe "boot" commands of this monitor operate on "image" files which
2474c609719bSwdenkcan be basicly anything, preceeded by a special header; see the
2475c609719bSwdenkdefinitions in include/image.h for details; basicly, the header
2476c609719bSwdenkdefines the following image properties:
2477c609719bSwdenk
2478c609719bSwdenk* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2479c609719bSwdenk  4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
24807f70e853Swdenk  LynxOS, pSOS, QNX, RTEMS, ARTOS;
24811f4bb37dSwdenk  Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2482c609719bSwdenk* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
24833d1e8a9dSwdenk  IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
24843d1e8a9dSwdenk  Currently supported: ARM, Intel x86, MIPS, NIOS, PowerPC).
2485c29fdfc1Swdenk* Compression Type (uncompressed, gzip, bzip2)
2486c609719bSwdenk* Load Address
2487c609719bSwdenk* Entry Point
2488c609719bSwdenk* Image Name
2489c609719bSwdenk* Image Timestamp
2490c609719bSwdenk
2491c609719bSwdenkThe header is marked by a special Magic Number, and both the header
2492c609719bSwdenkand the data portions of the image are secured against corruption by
2493c609719bSwdenkCRC32 checksums.
2494c609719bSwdenk
2495c609719bSwdenk
2496c609719bSwdenkLinux Support:
2497c609719bSwdenk==============
2498c609719bSwdenk
2499c609719bSwdenkAlthough U-Boot should support any OS or standalone application
25007152b1d0Swdenkeasily, the main focus has always been on Linux during the design of
2501c609719bSwdenkU-Boot.
2502c609719bSwdenk
2503c609719bSwdenkU-Boot includes many features that so far have been part of some
2504c609719bSwdenkspecial "boot loader" code within the Linux kernel. Also, any
2505c609719bSwdenk"initrd" images to be used are no longer part of one big Linux image;
2506c609719bSwdenkinstead, kernel and "initrd" are separate images. This implementation
25077152b1d0Swdenkserves several purposes:
2508c609719bSwdenk
2509c609719bSwdenk- the same features can be used for other OS or standalone
2510c609719bSwdenk  applications (for instance: using compressed images to reduce the
2511c609719bSwdenk  Flash memory footprint)
2512c609719bSwdenk
2513c609719bSwdenk- it becomes much easier to port new Linux kernel versions because
25147152b1d0Swdenk  lots of low-level, hardware dependent stuff are done by U-Boot
2515c609719bSwdenk
2516c609719bSwdenk- the same Linux kernel image can now be used with different "initrd"
2517c609719bSwdenk  images; of course this also means that different kernel images can
2518c609719bSwdenk  be run with the same "initrd". This makes testing easier (you don't
2519c609719bSwdenk  have to build a new "zImage.initrd" Linux image when you just
2520c609719bSwdenk  change a file in your "initrd"). Also, a field-upgrade of the
2521c609719bSwdenk  software is easier now.
2522c609719bSwdenk
2523c609719bSwdenk
2524c609719bSwdenkLinux HOWTO:
2525c609719bSwdenk============
2526c609719bSwdenk
2527c609719bSwdenkPorting Linux to U-Boot based systems:
2528c609719bSwdenk---------------------------------------
2529c609719bSwdenk
2530c609719bSwdenkU-Boot cannot save you from doing all the necessary modifications to
2531c609719bSwdenkconfigure the Linux device drivers for use with your target hardware
2532c609719bSwdenk(no, we don't intend to provide a full virtual machine interface to
2533c609719bSwdenkLinux :-).
2534c609719bSwdenk
2535c609719bSwdenkBut now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2536c609719bSwdenk
2537c609719bSwdenkJust make sure your machine specific header file (for instance
2538c609719bSwdenkinclude/asm-ppc/tqm8xx.h) includes the same definition of the Board
2539c609719bSwdenkInformation structure as we define in include/u-boot.h, and make
2540c609719bSwdenksure that your definition of IMAP_ADDR uses the same value as your
2541c609719bSwdenkU-Boot configuration in CFG_IMMR.
2542c609719bSwdenk
2543c609719bSwdenk
2544c609719bSwdenkConfiguring the Linux kernel:
2545c609719bSwdenk-----------------------------
2546c609719bSwdenk
2547c609719bSwdenkNo specific requirements for U-Boot. Make sure you have some root
2548c609719bSwdenkdevice (initial ramdisk, NFS) for your target system.
2549c609719bSwdenk
2550c609719bSwdenk
2551c609719bSwdenkBuilding a Linux Image:
2552c609719bSwdenk-----------------------
2553c609719bSwdenk
255424ee89b9SwdenkWith U-Boot, "normal" build targets like "zImage" or "bzImage" are
255524ee89b9Swdenknot used. If you use recent kernel source, a new build target
255624ee89b9Swdenk"uImage" will exist which automatically builds an image usable by
255724ee89b9SwdenkU-Boot. Most older kernels also have support for a "pImage" target,
255824ee89b9Swdenkwhich was introduced for our predecessor project PPCBoot and uses a
255924ee89b9Swdenk100% compatible format.
2560c609719bSwdenk
2561c609719bSwdenkExample:
2562c609719bSwdenk
2563c609719bSwdenk	make TQM850L_config
2564c609719bSwdenk	make oldconfig
2565c609719bSwdenk	make dep
256624ee89b9Swdenk	make uImage
2567c609719bSwdenk
256824ee89b9SwdenkThe "uImage" build target uses a special tool (in 'tools/mkimage') to
256924ee89b9Swdenkencapsulate a compressed Linux kernel image with header	 information,
257024ee89b9SwdenkCRC32 checksum etc. for use with U-Boot. This is what we are doing:
2571c609719bSwdenk
257224ee89b9Swdenk* build a standard "vmlinux" kernel image (in ELF binary format):
257324ee89b9Swdenk
257424ee89b9Swdenk* convert the kernel into a raw binary image:
257524ee89b9Swdenk
257624ee89b9Swdenk	${CROSS_COMPILE}-objcopy -O binary \
257724ee89b9Swdenk				 -R .note -R .comment \
257824ee89b9Swdenk				 -S vmlinux linux.bin
257924ee89b9Swdenk
258024ee89b9Swdenk* compress the binary image:
258124ee89b9Swdenk
258224ee89b9Swdenk	gzip -9 linux.bin
258324ee89b9Swdenk
258424ee89b9Swdenk* package compressed binary image for U-Boot:
258524ee89b9Swdenk
258624ee89b9Swdenk	mkimage -A ppc -O linux -T kernel -C gzip \
258724ee89b9Swdenk		-a 0 -e 0 -n "Linux Kernel Image" \
258824ee89b9Swdenk		-d linux.bin.gz uImage
258924ee89b9Swdenk
259024ee89b9Swdenk
259124ee89b9SwdenkThe "mkimage" tool can also be used to create ramdisk images for use
259224ee89b9Swdenkwith U-Boot, either separated from the Linux kernel image, or
259324ee89b9Swdenkcombined into one file. "mkimage" encapsulates the images with a 64
259424ee89b9Swdenkbyte header containing information about target architecture,
259524ee89b9Swdenkoperating system, image type, compression method, entry points, time
259624ee89b9Swdenkstamp, CRC32 checksums, etc.
259724ee89b9Swdenk
259824ee89b9Swdenk"mkimage" can be called in two ways: to verify existing images and
259924ee89b9Swdenkprint the header information, or to build new images.
2600c609719bSwdenk
2601c609719bSwdenkIn the first form (with "-l" option) mkimage lists the information
2602c609719bSwdenkcontained in the header of an existing U-Boot image; this includes
2603c609719bSwdenkchecksum verification:
2604c609719bSwdenk
2605c609719bSwdenk	tools/mkimage -l image
2606c609719bSwdenk	  -l ==> list image header information
2607c609719bSwdenk
2608c609719bSwdenkThe second form (with "-d" option) is used to build a U-Boot image
2609c609719bSwdenkfrom a "data file" which is used as image payload:
2610c609719bSwdenk
2611c609719bSwdenk	tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2612c609719bSwdenk		      -n name -d data_file image
2613c609719bSwdenk	  -A ==> set architecture to 'arch'
2614c609719bSwdenk	  -O ==> set operating system to 'os'
2615c609719bSwdenk	  -T ==> set image type to 'type'
2616c609719bSwdenk	  -C ==> set compression type 'comp'
2617c609719bSwdenk	  -a ==> set load address to 'addr' (hex)
2618c609719bSwdenk	  -e ==> set entry point to 'ep' (hex)
2619c609719bSwdenk	  -n ==> set image name to 'name'
2620c609719bSwdenk	  -d ==> use image data from 'datafile'
2621c609719bSwdenk
262269459791SwdenkRight now, all Linux kernels for PowerPC systems use the same load
262369459791Swdenkaddress (0x00000000), but the entry point address depends on the
262469459791Swdenkkernel version:
2625c609719bSwdenk
2626c609719bSwdenk- 2.2.x kernels have the entry point at 0x0000000C,
262724ee89b9Swdenk- 2.3.x and later kernels have the entry point at 0x00000000.
2628c609719bSwdenk
2629c609719bSwdenkSo a typical call to build a U-Boot image would read:
2630c609719bSwdenk
263124ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
263224ee89b9Swdenk	> -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
263324ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
263424ee89b9Swdenk	> examples/uImage.TQM850L
263524ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2636c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2637c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2638c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2639c609719bSwdenk	Load Address: 0x00000000
264024ee89b9Swdenk	Entry Point:  0x00000000
2641c609719bSwdenk
2642c609719bSwdenkTo verify the contents of the image (or check for corruption):
2643c609719bSwdenk
264424ee89b9Swdenk	-> tools/mkimage -l examples/uImage.TQM850L
264524ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2646c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2647c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2648c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2649c609719bSwdenk	Load Address: 0x00000000
265024ee89b9Swdenk	Entry Point:  0x00000000
2651c609719bSwdenk
2652c609719bSwdenkNOTE: for embedded systems where boot time is critical you can trade
2653c609719bSwdenkspeed for memory and install an UNCOMPRESSED image instead: this
2654c609719bSwdenkneeds more space in Flash, but boots much faster since it does not
2655c609719bSwdenkneed to be uncompressed:
2656c609719bSwdenk
265724ee89b9Swdenk	-> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
265824ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
265924ee89b9Swdenk	> -A ppc -O linux -T kernel -C none -a 0 -e 0 \
266024ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
266124ee89b9Swdenk	> examples/uImage.TQM850L-uncompressed
266224ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2663c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2664c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (uncompressed)
2665c609719bSwdenk	Data Size:    792160 Bytes = 773.59 kB = 0.76 MB
2666c609719bSwdenk	Load Address: 0x00000000
266724ee89b9Swdenk	Entry Point:  0x00000000
2668c609719bSwdenk
2669c609719bSwdenk
2670c609719bSwdenkSimilar you can build U-Boot images from a 'ramdisk.image.gz' file
2671c609719bSwdenkwhen your kernel is intended to use an initial ramdisk:
2672c609719bSwdenk
2673c609719bSwdenk	-> tools/mkimage -n 'Simple Ramdisk Image' \
2674c609719bSwdenk	> -A ppc -O linux -T ramdisk -C gzip \
2675c609719bSwdenk	> -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2676c609719bSwdenk	Image Name:   Simple Ramdisk Image
2677c609719bSwdenk	Created:      Wed Jan 12 14:01:50 2000
2678c609719bSwdenk	Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
2679c609719bSwdenk	Data Size:    566530 Bytes = 553.25 kB = 0.54 MB
2680c609719bSwdenk	Load Address: 0x00000000
2681c609719bSwdenk	Entry Point:  0x00000000
2682c609719bSwdenk
2683c609719bSwdenk
2684c609719bSwdenkInstalling a Linux Image:
2685c609719bSwdenk-------------------------
2686c609719bSwdenk
2687c609719bSwdenkTo downloading a U-Boot image over the serial (console) interface,
2688c609719bSwdenkyou must convert the image to S-Record format:
2689c609719bSwdenk
2690c609719bSwdenk	objcopy -I binary -O srec examples/image examples/image.srec
2691c609719bSwdenk
2692c609719bSwdenkThe 'objcopy' does not understand the information in the U-Boot
2693c609719bSwdenkimage header, so the resulting S-Record file will be relative to
2694c609719bSwdenkaddress 0x00000000. To load it to a given address, you need to
2695c609719bSwdenkspecify the target address as 'offset' parameter with the 'loads'
2696c609719bSwdenkcommand.
2697c609719bSwdenk
2698c609719bSwdenkExample: install the image to address 0x40100000 (which on the
2699c609719bSwdenkTQM8xxL is in the first Flash bank):
2700c609719bSwdenk
2701c609719bSwdenk	=> erase 40100000 401FFFFF
2702c609719bSwdenk
2703c609719bSwdenk	.......... done
2704c609719bSwdenk	Erased 8 sectors
2705c609719bSwdenk
2706c609719bSwdenk	=> loads 40100000
2707c609719bSwdenk	## Ready for S-Record download ...
2708c609719bSwdenk	~>examples/image.srec
2709c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2710c609719bSwdenk	...
2711c609719bSwdenk	15989 15990 15991 15992
2712c609719bSwdenk	[file transfer complete]
2713c609719bSwdenk	[connected]
2714c609719bSwdenk	## Start Addr = 0x00000000
2715c609719bSwdenk
2716c609719bSwdenk
2717c609719bSwdenkYou can check the success of the download using the 'iminfo' command;
2718c609719bSwdenkthis includes a checksum verification so you  can  be  sure  no	 data
2719c609719bSwdenkcorruption happened:
2720c609719bSwdenk
2721c609719bSwdenk	=> imi 40100000
2722c609719bSwdenk
2723c609719bSwdenk	## Checking Image at 40100000 ...
2724c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2725c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2726c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2727c609719bSwdenk	   Load Address: 00000000
2728c609719bSwdenk	   Entry Point:	 0000000c
2729c609719bSwdenk	   Verifying Checksum ... OK
2730c609719bSwdenk
2731c609719bSwdenk
2732c609719bSwdenkBoot Linux:
2733c609719bSwdenk-----------
2734c609719bSwdenk
2735c609719bSwdenkThe "bootm" command is used to boot an application that is stored in
2736c609719bSwdenkmemory (RAM or Flash). In case of a Linux kernel image, the contents
2737c609719bSwdenkof the "bootargs" environment variable is passed to the kernel as
2738c609719bSwdenkparameters. You can check and modify this variable using the
2739c609719bSwdenk"printenv" and "setenv" commands:
2740c609719bSwdenk
2741c609719bSwdenk
2742c609719bSwdenk	=> printenv bootargs
2743c609719bSwdenk	bootargs=root=/dev/ram
2744c609719bSwdenk
2745c609719bSwdenk	=> setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2746c609719bSwdenk
2747c609719bSwdenk	=> printenv bootargs
2748c609719bSwdenk	bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2749c609719bSwdenk
2750c609719bSwdenk	=> bootm 40020000
2751c609719bSwdenk	## Booting Linux kernel at 40020000 ...
2752c609719bSwdenk	   Image Name:	 2.2.13 for NFS on TQM850L
2753c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2754c609719bSwdenk	   Data Size:	 381681 Bytes = 372 kB = 0 MB
2755c609719bSwdenk	   Load Address: 00000000
2756c609719bSwdenk	   Entry Point:	 0000000c
2757c609719bSwdenk	   Verifying Checksum ... OK
2758c609719bSwdenk	   Uncompressing Kernel Image ... OK
2759c609719bSwdenk	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
2760c609719bSwdenk	Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2761c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2762c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2763c609719bSwdenk	Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2764c609719bSwdenk	...
2765c609719bSwdenk
2766c609719bSwdenkIf you want to boot a Linux kernel with initial ram disk, you pass
27677152b1d0Swdenkthe memory addresses of both the kernel and the initrd image (PPBCOOT
2768c609719bSwdenkformat!) to the "bootm" command:
2769c609719bSwdenk
2770c609719bSwdenk	=> imi 40100000 40200000
2771c609719bSwdenk
2772c609719bSwdenk	## Checking Image at 40100000 ...
2773c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2774c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2775c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2776c609719bSwdenk	   Load Address: 00000000
2777c609719bSwdenk	   Entry Point:	 0000000c
2778c609719bSwdenk	   Verifying Checksum ... OK
2779c609719bSwdenk
2780c609719bSwdenk	## Checking Image at 40200000 ...
2781c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2782c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2783c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2784c609719bSwdenk	   Load Address: 00000000
2785c609719bSwdenk	   Entry Point:	 00000000
2786c609719bSwdenk	   Verifying Checksum ... OK
2787c609719bSwdenk
2788c609719bSwdenk	=> bootm 40100000 40200000
2789c609719bSwdenk	## Booting Linux kernel at 40100000 ...
2790c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2791c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2792c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2793c609719bSwdenk	   Load Address: 00000000
2794c609719bSwdenk	   Entry Point:	 0000000c
2795c609719bSwdenk	   Verifying Checksum ... OK
2796c609719bSwdenk	   Uncompressing Kernel Image ... OK
2797c609719bSwdenk	## Loading RAMDisk Image at 40200000 ...
2798c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2799c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2800c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2801c609719bSwdenk	   Load Address: 00000000
2802c609719bSwdenk	   Entry Point:	 00000000
2803c609719bSwdenk	   Verifying Checksum ... OK
2804c609719bSwdenk	   Loading Ramdisk ... OK
2805c609719bSwdenk	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
2806c609719bSwdenk	Boot arguments: root=/dev/ram
2807c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2808c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2809c609719bSwdenk	...
2810c609719bSwdenk	RAMDISK: Compressed image found at block 0
2811c609719bSwdenk	VFS: Mounted root (ext2 filesystem).
2812c609719bSwdenk
2813c609719bSwdenk	bash#
2814c609719bSwdenk
28156069ff26SwdenkMore About U-Boot Image Types:
28166069ff26Swdenk------------------------------
28176069ff26Swdenk
28186069ff26SwdenkU-Boot supports the following image types:
28196069ff26Swdenk
28206069ff26Swdenk   "Standalone Programs" are directly runnable in the environment
28216069ff26Swdenk	provided by U-Boot; it is expected that (if they behave
28226069ff26Swdenk	well) you can continue to work in U-Boot after return from
28236069ff26Swdenk	the Standalone Program.
28246069ff26Swdenk   "OS Kernel Images" are usually images of some Embedded OS which
28256069ff26Swdenk	will take over control completely. Usually these programs
28266069ff26Swdenk	will install their own set of exception handlers, device
28276069ff26Swdenk	drivers, set up the MMU, etc. - this means, that you cannot
28286069ff26Swdenk	expect to re-enter U-Boot except by resetting the CPU.
28296069ff26Swdenk   "RAMDisk Images" are more or less just data blocks, and their
28306069ff26Swdenk	parameters (address, size) are passed to an OS kernel that is
28316069ff26Swdenk	being started.
28326069ff26Swdenk   "Multi-File Images" contain several images, typically an OS
28336069ff26Swdenk	(Linux) kernel image and one or more data images like
28346069ff26Swdenk	RAMDisks. This construct is useful for instance when you want
28356069ff26Swdenk	to boot over the network using BOOTP etc., where the boot
28366069ff26Swdenk	server provides just a single image file, but you want to get
28376069ff26Swdenk	for instance an OS kernel and a RAMDisk image.
28386069ff26Swdenk
28396069ff26Swdenk	"Multi-File Images" start with a list of image sizes, each
28406069ff26Swdenk	image size (in bytes) specified by an "uint32_t" in network
28416069ff26Swdenk	byte order. This list is terminated by an "(uint32_t)0".
28426069ff26Swdenk	Immediately after the terminating 0 follow the images, one by
28436069ff26Swdenk	one, all aligned on "uint32_t" boundaries (size rounded up to
28446069ff26Swdenk	a multiple of 4 bytes).
28456069ff26Swdenk
28466069ff26Swdenk   "Firmware Images" are binary images containing firmware (like
28476069ff26Swdenk	U-Boot or FPGA images) which usually will be programmed to
28486069ff26Swdenk	flash memory.
28496069ff26Swdenk
28506069ff26Swdenk   "Script files" are command sequences that will be executed by
28516069ff26Swdenk	U-Boot's command interpreter; this feature is especially
28526069ff26Swdenk	useful when you configure U-Boot to use a real shell (hush)
28536069ff26Swdenk	as command interpreter.
28546069ff26Swdenk
2855c609719bSwdenk
2856c609719bSwdenkStandalone HOWTO:
2857c609719bSwdenk=================
2858c609719bSwdenk
2859c609719bSwdenkOne of the features of U-Boot is that you can dynamically load and
2860c609719bSwdenkrun "standalone" applications, which can use some resources of
2861c609719bSwdenkU-Boot like console I/O functions or interrupt services.
2862c609719bSwdenk
2863c609719bSwdenkTwo simple examples are included with the sources:
2864c609719bSwdenk
2865c609719bSwdenk"Hello World" Demo:
2866c609719bSwdenk-------------------
2867c609719bSwdenk
2868c609719bSwdenk'examples/hello_world.c' contains a small "Hello World" Demo
2869c609719bSwdenkapplication; it is automatically compiled when you build U-Boot.
2870c609719bSwdenkIt's configured to run at address 0x00040004, so you can play with it
2871c609719bSwdenklike that:
2872c609719bSwdenk
2873c609719bSwdenk	=> loads
2874c609719bSwdenk	## Ready for S-Record download ...
2875c609719bSwdenk	~>examples/hello_world.srec
2876c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2877c609719bSwdenk	[file transfer complete]
2878c609719bSwdenk	[connected]
2879c609719bSwdenk	## Start Addr = 0x00040004
2880c609719bSwdenk
2881c609719bSwdenk	=> go 40004 Hello World! This is a test.
2882c609719bSwdenk	## Starting application at 0x00040004 ...
2883c609719bSwdenk	Hello World
2884c609719bSwdenk	argc = 7
2885c609719bSwdenk	argv[0] = "40004"
2886c609719bSwdenk	argv[1] = "Hello"
2887c609719bSwdenk	argv[2] = "World!"
2888c609719bSwdenk	argv[3] = "This"
2889c609719bSwdenk	argv[4] = "is"
2890c609719bSwdenk	argv[5] = "a"
2891c609719bSwdenk	argv[6] = "test."
2892c609719bSwdenk	argv[7] = "<NULL>"
2893c609719bSwdenk	Hit any key to exit ...
2894c609719bSwdenk
2895c609719bSwdenk	## Application terminated, rc = 0x0
2896c609719bSwdenk
2897c609719bSwdenkAnother example, which demonstrates how to register a CPM interrupt
2898c609719bSwdenkhandler with the U-Boot code, can be found in 'examples/timer.c'.
2899c609719bSwdenkHere, a CPM timer is set up to generate an interrupt every second.
2900c609719bSwdenkThe interrupt service routine is trivial, just printing a '.'
2901c609719bSwdenkcharacter, but this is just a demo program. The application can be
2902c609719bSwdenkcontrolled by the following keys:
2903c609719bSwdenk
2904c609719bSwdenk	? - print current values og the CPM Timer registers
2905c609719bSwdenk	b - enable interrupts and start timer
2906c609719bSwdenk	e - stop timer and disable interrupts
2907c609719bSwdenk	q - quit application
2908c609719bSwdenk
2909c609719bSwdenk	=> loads
2910c609719bSwdenk	## Ready for S-Record download ...
2911c609719bSwdenk	~>examples/timer.srec
2912c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2913c609719bSwdenk	[file transfer complete]
2914c609719bSwdenk	[connected]
2915c609719bSwdenk	## Start Addr = 0x00040004
2916c609719bSwdenk
2917c609719bSwdenk	=> go 40004
2918c609719bSwdenk	## Starting application at 0x00040004 ...
2919c609719bSwdenk	TIMERS=0xfff00980
2920c609719bSwdenk	Using timer 1
2921c609719bSwdenk	  tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2922c609719bSwdenk
2923c609719bSwdenkHit 'b':
2924c609719bSwdenk	[q, b, e, ?] Set interval 1000000 us
2925c609719bSwdenk	Enabling timer
2926c609719bSwdenkHit '?':
2927c609719bSwdenk	[q, b, e, ?] ........
2928c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2929c609719bSwdenkHit '?':
2930c609719bSwdenk	[q, b, e, ?] .
2931c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2932c609719bSwdenkHit '?':
2933c609719bSwdenk	[q, b, e, ?] .
2934c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2935c609719bSwdenkHit '?':
2936c609719bSwdenk	[q, b, e, ?] .
2937c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2938c609719bSwdenkHit 'e':
2939c609719bSwdenk	[q, b, e, ?] ...Stopping timer
2940c609719bSwdenkHit 'q':
2941c609719bSwdenk	[q, b, e, ?] ## Application terminated, rc = 0x0
2942c609719bSwdenk
2943c609719bSwdenk
294485ec0bccSwdenkMinicom warning:
294585ec0bccSwdenk================
294685ec0bccSwdenk
29477152b1d0SwdenkOver time, many people have reported problems when trying to use the
294885ec0bccSwdenk"minicom" terminal emulation program for serial download. I (wd)
294985ec0bccSwdenkconsider minicom to be broken, and recommend not to use it. Under
2950f07771ccSwdenkUnix, I recommend to use C-Kermit for general purpose use (and
295185ec0bccSwdenkespecially for kermit binary protocol download ("loadb" command), and
295285ec0bccSwdenkuse "cu" for S-Record download ("loads" command).
295385ec0bccSwdenk
295452f52c14SwdenkNevertheless, if you absolutely want to use it try adding this
295552f52c14Swdenkconfiguration to your "File transfer protocols" section:
295652f52c14Swdenk
295752f52c14Swdenk	   Name	   Program			Name U/D FullScr IO-Red. Multi
295852f52c14Swdenk	X  kermit  /usr/bin/kermit -i -l %l -s	 Y    U	   Y	   N	  N
295952f52c14Swdenk	Y  kermit  /usr/bin/kermit -i -l %l -r	 N    D	   Y	   N	  N
296052f52c14Swdenk
296152f52c14Swdenk
2962c609719bSwdenkNetBSD Notes:
2963c609719bSwdenk=============
2964c609719bSwdenk
2965c609719bSwdenkStarting at version 0.9.2, U-Boot supports NetBSD both as host
2966c609719bSwdenk(build U-Boot) and target system (boots NetBSD/mpc8xx).
2967c609719bSwdenk
2968c609719bSwdenkBuilding requires a cross environment; it is known to work on
2969c609719bSwdenkNetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2970c609719bSwdenkneed gmake since the Makefiles are not compatible with BSD make).
2971c609719bSwdenkNote that the cross-powerpc package does not install include files;
2972c609719bSwdenkattempting to build U-Boot will fail because <machine/ansi.h> is
2973c609719bSwdenkmissing.  This file has to be installed and patched manually:
2974c609719bSwdenk
2975c609719bSwdenk	# cd /usr/pkg/cross/powerpc-netbsd/include
2976c609719bSwdenk	# mkdir powerpc
2977c609719bSwdenk	# ln -s powerpc machine
2978c609719bSwdenk	# cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2979c609719bSwdenk	# ${EDIT} powerpc/ansi.h	## must remove __va_list, _BSD_VA_LIST
2980c609719bSwdenk
2981c609719bSwdenkNative builds *don't* work due to incompatibilities between native
2982c609719bSwdenkand U-Boot include files.
2983c609719bSwdenk
2984c609719bSwdenkBooting assumes that (the first part of) the image booted is a
2985c609719bSwdenkstage-2 loader which in turn loads and then invokes the kernel
2986c609719bSwdenkproper. Loader sources will eventually appear in the NetBSD source
2987c609719bSwdenktree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2988c609719bSwdenkmeantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2989c609719bSwdenkdetails.
2990c609719bSwdenk
2991c609719bSwdenk
2992c609719bSwdenkImplementation Internals:
2993c609719bSwdenk=========================
2994c609719bSwdenk
2995c609719bSwdenkThe following is not intended to be a complete description of every
2996c609719bSwdenkimplementation detail. However, it should help to understand the
2997c609719bSwdenkinner workings of U-Boot and make it easier to port it to custom
2998c609719bSwdenkhardware.
2999c609719bSwdenk
3000c609719bSwdenk
3001c609719bSwdenkInitial Stack, Global Data:
3002c609719bSwdenk---------------------------
3003c609719bSwdenk
3004c609719bSwdenkThe implementation of U-Boot is complicated by the fact that U-Boot
3005c609719bSwdenkstarts running out of ROM (flash memory), usually without access to
3006c609719bSwdenksystem RAM (because the memory controller is not initialized yet).
3007c609719bSwdenkThis means that we don't have writable Data or BSS segments, and BSS
3008c609719bSwdenkis not initialized as zero. To be able to get a C environment working
3009c609719bSwdenkat all, we have to allocate at least a minimal stack. Implementation
3010c609719bSwdenkoptions for this are defined and restricted by the CPU used: Some CPU
3011c609719bSwdenkmodels provide on-chip memory (like the IMMR area on MPC8xx and
3012c609719bSwdenkMPC826x processors), on others (parts of) the data cache can be
3013c609719bSwdenklocked as (mis-) used as memory, etc.
3014c609719bSwdenk
30157152b1d0Swdenk	Chris Hallinan posted a good summary of	 these	issues	to  the
301643d9616cSwdenk	u-boot-users mailing list:
301743d9616cSwdenk
301843d9616cSwdenk	Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
301943d9616cSwdenk	From: "Chris Hallinan" <clh@net1plus.com>
302043d9616cSwdenk	Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
302143d9616cSwdenk	...
302243d9616cSwdenk
302343d9616cSwdenk	Correct me if I'm wrong, folks, but the way I understand it
302443d9616cSwdenk	is this: Using DCACHE as initial RAM for Stack, etc, does not
302543d9616cSwdenk	require any physical RAM backing up the cache. The cleverness
302643d9616cSwdenk	is that the cache is being used as a temporary supply of
302743d9616cSwdenk	necessary storage before the SDRAM controller is setup. It's
302843d9616cSwdenk	beyond the scope of this list to expain the details, but you
302943d9616cSwdenk	can see how this works by studying the cache architecture and
303043d9616cSwdenk	operation in the architecture and processor-specific manuals.
303143d9616cSwdenk
303243d9616cSwdenk	OCM is On Chip Memory, which I believe the 405GP has 4K. It
303343d9616cSwdenk	is another option for the system designer to use as an
303443d9616cSwdenk	initial stack/ram area prior to SDRAM being available. Either
303543d9616cSwdenk	option should work for you. Using CS 4 should be fine if your
303643d9616cSwdenk	board designers haven't used it for something that would
303743d9616cSwdenk	cause you grief during the initial boot! It is frequently not
303843d9616cSwdenk	used.
303943d9616cSwdenk
304043d9616cSwdenk	CFG_INIT_RAM_ADDR should be somewhere that won't interfere
304143d9616cSwdenk	with your processor/board/system design. The default value
304243d9616cSwdenk	you will find in any recent u-boot distribution in
304343d9616cSwdenk	Walnut405.h should work for you. I'd set it to a value larger
304443d9616cSwdenk	than your SDRAM module. If you have a 64MB SDRAM module, set
304543d9616cSwdenk	it above 400_0000. Just make sure your board has no resources
304643d9616cSwdenk	that are supposed to respond to that address! That code in
304743d9616cSwdenk	start.S has been around a while and should work as is when
304843d9616cSwdenk	you get the config right.
304943d9616cSwdenk
305043d9616cSwdenk	-Chris Hallinan
305143d9616cSwdenk	DS4.COM, Inc.
305243d9616cSwdenk
3053c609719bSwdenkIt is essential to remember this, since it has some impact on the C
3054c609719bSwdenkcode for the initialization procedures:
3055c609719bSwdenk
3056c609719bSwdenk* Initialized global data (data segment) is read-only. Do not attempt
3057c609719bSwdenk  to write it.
3058c609719bSwdenk
3059c609719bSwdenk* Do not use any unitialized global data (or implicitely initialized
3060c609719bSwdenk  as zero data - BSS segment) at all - this is undefined, initiali-
30617152b1d0Swdenk  zation is performed later (when relocating to RAM).
3062c609719bSwdenk
3063c609719bSwdenk* Stack space is very limited. Avoid big data buffers or things like
3064c609719bSwdenk  that.
3065c609719bSwdenk
3066c609719bSwdenkHaving only the stack as writable memory limits means we cannot use
3067c609719bSwdenknormal global data to share information beween the code. But it
3068c609719bSwdenkturned out that the implementation of U-Boot can be greatly
3069c609719bSwdenksimplified by making a global data structure (gd_t) available to all
3070c609719bSwdenkfunctions. We could pass a pointer to this data as argument to _all_
3071c609719bSwdenkfunctions, but this would bloat the code. Instead we use a feature of
3072c609719bSwdenkthe GCC compiler (Global Register Variables) to share the data: we
3073c609719bSwdenkplace a pointer (gd) to the global data into a register which we
3074c609719bSwdenkreserve for this purpose.
3075c609719bSwdenk
30767152b1d0SwdenkWhen choosing a register for such a purpose we are restricted by the
3077c609719bSwdenkrelevant  (E)ABI  specifications for the current architecture, and by
3078c609719bSwdenkGCC's implementation.
3079c609719bSwdenk
3080c609719bSwdenkFor PowerPC, the following registers have specific use:
3081c609719bSwdenk	R1:	stack pointer
3082c609719bSwdenk	R2:	TOC pointer
3083c609719bSwdenk	R3-R4:	parameter passing and return values
3084c609719bSwdenk	R5-R10: parameter passing
3085c609719bSwdenk	R13:	small data area pointer
3086c609719bSwdenk	R30:	GOT pointer
3087c609719bSwdenk	R31:	frame pointer
3088c609719bSwdenk
3089c609719bSwdenk	(U-Boot also uses R14 as internal GOT pointer.)
3090c609719bSwdenk
3091c609719bSwdenk    ==> U-Boot will use R29 to hold a pointer to the global data
3092c609719bSwdenk
3093c609719bSwdenk    Note: on PPC, we could use a static initializer (since the
3094c609719bSwdenk    address of the global data structure is known at compile time),
3095c609719bSwdenk    but it turned out that reserving a register results in somewhat
3096c609719bSwdenk    smaller code - although the code savings are not that big (on
3097c609719bSwdenk    average for all boards 752 bytes for the whole U-Boot image,
3098c609719bSwdenk    624 text + 127 data).
3099c609719bSwdenk
3100c609719bSwdenkOn ARM, the following registers are used:
3101c609719bSwdenk
3102c609719bSwdenk	R0:	function argument word/integer result
3103c609719bSwdenk	R1-R3:	function argument word
3104c609719bSwdenk	R9:	GOT pointer
3105c609719bSwdenk	R10:	stack limit (used only if stack checking if enabled)
3106c609719bSwdenk	R11:	argument (frame) pointer
3107c609719bSwdenk	R12:	temporary workspace
3108c609719bSwdenk	R13:	stack pointer
3109c609719bSwdenk	R14:	link register
3110c609719bSwdenk	R15:	program counter
3111c609719bSwdenk
3112c609719bSwdenk    ==> U-Boot will use R8 to hold a pointer to the global data
3113c609719bSwdenk
3114c609719bSwdenk
3115c609719bSwdenkMemory Management:
3116c609719bSwdenk------------------
3117c609719bSwdenk
3118c609719bSwdenkU-Boot runs in system state and uses physical addresses, i.e. the
3119c609719bSwdenkMMU is not used either for address mapping nor for memory protection.
3120c609719bSwdenk
3121c609719bSwdenkThe available memory is mapped to fixed addresses using the memory
3122c609719bSwdenkcontroller. In this process, a contiguous block is formed for each
3123c609719bSwdenkmemory type (Flash, SDRAM, SRAM), even when it consists of several
3124c609719bSwdenkphysical memory banks.
3125c609719bSwdenk
3126c609719bSwdenkU-Boot is installed in the first 128 kB of the first Flash bank (on
3127c609719bSwdenkTQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3128c609719bSwdenkbooting and sizing and initializing DRAM, the code relocates itself
3129c609719bSwdenkto the upper end of DRAM. Immediately below the U-Boot code some
3130c609719bSwdenkmemory is reserved for use by malloc() [see CFG_MALLOC_LEN
3131c609719bSwdenkconfiguration setting]. Below that, a structure with global Board
3132c609719bSwdenkInfo data is placed, followed by the stack (growing downward).
3133c609719bSwdenk
3134c609719bSwdenkAdditionally, some exception handler code is copied to the low 8 kB
3135c609719bSwdenkof DRAM (0x00000000 ... 0x00001FFF).
3136c609719bSwdenk
3137c609719bSwdenkSo a typical memory configuration with 16 MB of DRAM could look like
3138c609719bSwdenkthis:
3139c609719bSwdenk
3140c609719bSwdenk	0x0000 0000	Exception Vector code
3141c609719bSwdenk	      :
3142c609719bSwdenk	0x0000 1FFF
3143c609719bSwdenk	0x0000 2000	Free for Application Use
3144c609719bSwdenk	      :
3145c609719bSwdenk	      :
3146c609719bSwdenk
3147c609719bSwdenk	      :
3148c609719bSwdenk	      :
3149c609719bSwdenk	0x00FB FF20	Monitor Stack (Growing downward)
3150c609719bSwdenk	0x00FB FFAC	Board Info Data and permanent copy of global data
3151c609719bSwdenk	0x00FC 0000	Malloc Arena
3152c609719bSwdenk	      :
3153c609719bSwdenk	0x00FD FFFF
3154c609719bSwdenk	0x00FE 0000	RAM Copy of Monitor Code
3155c609719bSwdenk	...		eventually: LCD or video framebuffer
3156c609719bSwdenk	...		eventually: pRAM (Protected RAM - unchanged by reset)
3157c609719bSwdenk	0x00FF FFFF	[End of RAM]
3158c609719bSwdenk
3159c609719bSwdenk
3160c609719bSwdenkSystem Initialization:
3161c609719bSwdenk----------------------
3162c609719bSwdenk
3163c609719bSwdenkIn the reset configuration, U-Boot starts at the reset entry point
3164c609719bSwdenk(on most PowerPC systens at address 0x00000100). Because of the reset
3165c609719bSwdenkconfiguration for CS0# this is a mirror of the onboard Flash memory.
31667152b1d0SwdenkTo be able to re-map memory U-Boot then jumps to its link address.
3167c609719bSwdenkTo be able to implement the initialization code in C, a (small!)
3168c609719bSwdenkinitial stack is set up in the internal Dual Ported RAM (in case CPUs
3169c609719bSwdenkwhich provide such a feature like MPC8xx or MPC8260), or in a locked
3170c609719bSwdenkpart of the data cache. After that, U-Boot initializes the CPU core,
3171c609719bSwdenkthe caches and the SIU.
3172c609719bSwdenk
3173c609719bSwdenkNext, all (potentially) available memory banks are mapped using a
3174c609719bSwdenkpreliminary mapping. For example, we put them on 512 MB boundaries
3175c609719bSwdenk(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3176c609719bSwdenkon 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3177c609719bSwdenkprogrammed for SDRAM access. Using the temporary configuration, a
3178c609719bSwdenksimple memory test is run that determines the size of the SDRAM
3179c609719bSwdenkbanks.
3180c609719bSwdenk
3181c609719bSwdenkWhen there is more than one SDRAM bank, and the banks are of
31827152b1d0Swdenkdifferent size, the largest is mapped first. For equal size, the first
3183c609719bSwdenkbank (CS2#) is mapped first. The first mapping is always for address
3184c609719bSwdenk0x00000000, with any additional banks following immediately to create
3185c609719bSwdenkcontiguous memory starting from 0.
3186c609719bSwdenk
3187c609719bSwdenkThen, the monitor installs itself at the upper end of the SDRAM area
3188c609719bSwdenkand allocates memory for use by malloc() and for the global Board
3189c609719bSwdenkInfo data; also, the exception vector code is copied to the low RAM
3190c609719bSwdenkpages, and the final stack is set up.
3191c609719bSwdenk
3192c609719bSwdenkOnly after this relocation will you have a "normal" C environment;
3193c609719bSwdenkuntil that you are restricted in several ways, mostly because you are
3194c609719bSwdenkrunning from ROM, and because the code will have to be relocated to a
3195c609719bSwdenknew address in RAM.
3196c609719bSwdenk
3197c609719bSwdenk
3198c609719bSwdenkU-Boot Porting Guide:
3199c609719bSwdenk----------------------
3200c609719bSwdenk
3201c609719bSwdenk[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
32026aff3115Swdenklist, October 2002]
3203c609719bSwdenk
3204c609719bSwdenk
3205c609719bSwdenkint main (int argc, char *argv[])
3206c609719bSwdenk{
3207c609719bSwdenk	sighandler_t no_more_time;
3208c609719bSwdenk
3209c609719bSwdenk	signal (SIGALRM, no_more_time);
3210c609719bSwdenk	alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3211c609719bSwdenk
3212c609719bSwdenk	if (available_money > available_manpower) {
3213c609719bSwdenk		pay consultant to port U-Boot;
3214c609719bSwdenk		return 0;
3215c609719bSwdenk	}
3216c609719bSwdenk
3217c609719bSwdenk	Download latest U-Boot source;
3218c609719bSwdenk
32196aff3115Swdenk	Subscribe to u-boot-users mailing list;
32206aff3115Swdenk
3221c609719bSwdenk	if (clueless) {
3222c609719bSwdenk		email ("Hi, I am new to U-Boot, how do I get started?");
3223c609719bSwdenk	}
3224c609719bSwdenk
3225c609719bSwdenk	while (learning) {
3226c609719bSwdenk		Read the README file in the top level directory;
32277cb22f97Swdenk		Read http://www.denx.de/twiki/bin/view/DULG/Manual ;
3228c609719bSwdenk		Read the source, Luke;
3229c609719bSwdenk	}
3230c609719bSwdenk
3231c609719bSwdenk	if (available_money > toLocalCurrency ($2500)) {
3232c609719bSwdenk		Buy a BDI2000;
3233c609719bSwdenk	} else {
3234c609719bSwdenk		Add a lot of aggravation and time;
3235c609719bSwdenk	}
3236c609719bSwdenk
3237c609719bSwdenk	Create your own board support subdirectory;
3238c609719bSwdenk
32396aff3115Swdenk	Create your own board config file;
32406aff3115Swdenk
3241c609719bSwdenk	while (!running) {
3242c609719bSwdenk		do {
3243c609719bSwdenk			Add / modify source code;
3244c609719bSwdenk		} until (compiles);
3245c609719bSwdenk		Debug;
3246c609719bSwdenk		if (clueless)
3247c609719bSwdenk			email ("Hi, I am having problems...");
3248c609719bSwdenk	}
3249c609719bSwdenk	Send patch file to Wolfgang;
3250c609719bSwdenk
3251c609719bSwdenk	return 0;
3252c609719bSwdenk}
3253c609719bSwdenk
3254c609719bSwdenkvoid no_more_time (int sig)
3255c609719bSwdenk{
3256c609719bSwdenk      hire_a_guru();
3257c609719bSwdenk}
3258c609719bSwdenk
3259c609719bSwdenk
3260c609719bSwdenkCoding Standards:
3261c609719bSwdenk-----------------
3262c609719bSwdenk
3263c609719bSwdenkAll contributions to U-Boot should conform to the Linux kernel
3264c609719bSwdenkcoding style; see the file "Documentation/CodingStyle" in your Linux
3265c609719bSwdenkkernel source directory.
3266c609719bSwdenk
3267c609719bSwdenkPlease note that U-Boot is implemented in C (and to some small parts
3268c609719bSwdenkin Assembler); no C++ is used, so please do not use C++ style
3269c609719bSwdenkcomments (//) in your code.
3270c609719bSwdenk
3271c178d3daSwdenkPlease also stick to the following formatting rules:
3272180d3f74Swdenk- remove any trailing white space
3273180d3f74Swdenk- use TAB characters for indentation, not spaces
3274180d3f74Swdenk- make sure NOT to use DOS '\r\n' line feeds
3275180d3f74Swdenk- do not add more than 2 empty lines to source files
3276180d3f74Swdenk- do not add trailing empty lines to source files
3277180d3f74Swdenk
3278c609719bSwdenkSubmissions which do not conform to the standards may be returned
3279c609719bSwdenkwith a request to reformat the changes.
3280c609719bSwdenk
3281c609719bSwdenk
3282c609719bSwdenkSubmitting Patches:
3283c609719bSwdenk-------------------
3284c609719bSwdenk
3285c609719bSwdenkSince the number of patches for U-Boot is growing, we need to
3286c609719bSwdenkestablish some rules. Submissions which do not conform to these rules
3287c609719bSwdenkmay be rejected, even when they contain important and valuable stuff.
3288c609719bSwdenk
3289c609719bSwdenk
3290c609719bSwdenkWhen you send a patch, please include the following information with
3291c609719bSwdenkit:
3292c609719bSwdenk
3293c609719bSwdenk* For bug fixes: a description of the bug and how your patch fixes
3294c609719bSwdenk  this bug. Please try to include a way of demonstrating that the
3295c609719bSwdenk  patch actually fixes something.
3296c609719bSwdenk
3297c609719bSwdenk* For new features: a description of the feature and your
3298c609719bSwdenk  implementation.
3299c609719bSwdenk
3300c609719bSwdenk* A CHANGELOG entry as plaintext (separate from the patch)
3301c609719bSwdenk
3302c609719bSwdenk* For major contributions, your entry to the CREDITS file
3303c609719bSwdenk
3304c609719bSwdenk* When you add support for a new board, don't forget to add this
3305c609719bSwdenk  board to the MAKEALL script, too.
3306c609719bSwdenk
3307c609719bSwdenk* If your patch adds new configuration options, don't forget to
3308c609719bSwdenk  document these in the README file.
3309c609719bSwdenk
3310c609719bSwdenk* The patch itself. If you are accessing the CVS repository use "cvs
3311c609719bSwdenk  update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3312c609719bSwdenk  version of diff does not support these options, then get the latest
3313c609719bSwdenk  version of GNU diff.
3314c609719bSwdenk
33156dff5529Swdenk  The current directory when running this command shall be the top
33166dff5529Swdenk  level directory of the U-Boot source tree, or it's parent directory
33176dff5529Swdenk  (i. e. please make sure that your patch includes sufficient
33186dff5529Swdenk  directory information for the affected files).
33196dff5529Swdenk
3320c609719bSwdenk  We accept patches as plain text, MIME attachments or as uuencoded
3321c609719bSwdenk  gzipped text.
3322c609719bSwdenk
332352f52c14Swdenk* If one logical set of modifications affects or creates several
332452f52c14Swdenk  files, all these changes shall be submitted in a SINGLE patch file.
332552f52c14Swdenk
332652f52c14Swdenk* Changesets that contain different, unrelated modifications shall be
332752f52c14Swdenk  submitted as SEPARATE patches, one patch per changeset.
332852f52c14Swdenk
332952f52c14Swdenk
3330c609719bSwdenkNotes:
3331c609719bSwdenk
3332c609719bSwdenk* Before sending the patch, run the MAKEALL script on your patched
3333c609719bSwdenk  source tree and make sure that no errors or warnings are reported
3334c609719bSwdenk  for any of the boards.
3335c609719bSwdenk
3336c609719bSwdenk* Keep your modifications to the necessary minimum: A patch
3337c609719bSwdenk  containing several unrelated changes or arbitrary reformats will be
3338c609719bSwdenk  returned with a request to re-formatting / split it.
3339c609719bSwdenk
3340c609719bSwdenk* If you modify existing code, make sure that your new code does not
3341c609719bSwdenk  add to the memory footprint of the code ;-) Small is beautiful!
3342c609719bSwdenk  When adding new features, these should compile conditionally only
3343c609719bSwdenk  (using #ifdef), and the resulting code with the new feature
3344c609719bSwdenk  disabled must not need more memory than the old code without your
3345c609719bSwdenk  modification.
3346