xref: /openbmc/u-boot/README (revision 52f52c1494eedaeacccad6e2331f4f638b48f5ab)
1c609719bSwdenk#
2c609719bSwdenk# (C) Copyright 2000 - 2002
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
122c609719bSwdenk- board		Board dependend files
123c609719bSwdenk- common	Misc architecture independend functions
124c609719bSwdenk- cpu		CPU specific files
125c609719bSwdenk- disk		Code for disk drive partition handling
126c609719bSwdenk- doc		Documentation (don't expect too much)
127c609719bSwdenk- drivers	Common used device drivers
128c609719bSwdenk- dtt		Digital Thermometer and Thermostat drivers
129c609719bSwdenk- examples	Example code for standalone applications, etc.
130c609719bSwdenk- include	Header Files
131c609719bSwdenk- disk		Harddisk interface code
132c609719bSwdenk- net		Networking code
133c609719bSwdenk- ppc		Files generic to PowerPC architecture
134c609719bSwdenk- post		Power On Self Test
135c609719bSwdenk- post/arch		Symlink to architecture specific Power On Self Test
136c609719bSwdenk- post/arch-ppc		PowerPC architecture specific Power On Self Test
137c609719bSwdenk- post/cpu/mpc8260	MPC8260 CPU specific Power On Self Test
138c609719bSwdenk- post/cpu/mpc8xx	MPC8xx CPU specific Power On Self Test
139c609719bSwdenk- rtc		Real Time Clock drivers
140c609719bSwdenk- tools		Tools to build S-Record or U-Boot images, etc.
141c609719bSwdenk
142c609719bSwdenk- cpu/74xx_7xx	Files specific to Motorola MPC74xx and 7xx CPUs
1430db5bca8Swdenk- cpu/mpc5xx	Files specific to Motorola MPC5xx  CPUs
144c609719bSwdenk- cpu/mpc8xx	Files specific to Motorola MPC8xx  CPUs
145c609719bSwdenk- cpu/mpc824x	Files specific to Motorola MPC824x CPUs
146c609719bSwdenk- cpu/mpc8260	Files specific to Motorola MPC8260 CPU
147c609719bSwdenk- cpu/ppc4xx	Files specific to IBM	   4xx	   CPUs
148c609719bSwdenk
1493bac3513Swdenk- board/LEOX/   Files specific to boards manufactured by The LEOX team
1503bac3513Swdenk- board/LEOX/elpt860	Files specific to ELPT860 boards
151c609719bSwdenk- board/RPXClassic
152c609719bSwdenk		Files specific to RPXClassic boards
153c609719bSwdenk- board/RPXlite	Files specific to RPXlite    boards
1542abbe075Swdenk- board/at91rm9200dk Files specific to AT91RM9200DK boards
155c609719bSwdenk- board/c2mon	Files specific to c2mon	     boards
1560db5bca8Swdenk- board/cmi	Files specific to cmi        boards
157c609719bSwdenk- board/cogent	Files specific to Cogent     boards
158c609719bSwdenk		(need further configuration)
159c609719bSwdenk		Files specific to CPCIISER4  boards
160c609719bSwdenk- board/cpu86	Files specific to CPU86      boards
161c609719bSwdenk- board/cray/	Files specific to boards manufactured by Cray
162c609719bSwdenk- board/cray/L1		Files specific to L1         boards
163c609719bSwdenk- board/cu824	Files specific to CU824	     boards
164c609719bSwdenk- board/ebony   Files specific to IBM Ebony board
165c609719bSwdenk- board/eric	Files specific to ERIC	     boards
166c609719bSwdenk- board/esd/	Files specific to boards manufactured by ESD
167c609719bSwdenk- board/esd/adciop	Files specific to ADCIOP     boards
168c609719bSwdenk- board/esd/ar405	Files specific to AR405	     boards
169c609719bSwdenk- board/esd/canbt	Files specific to CANBT	     boards
170c609719bSwdenk- board/esd/cpci405	Files specific to CPCI405    boards
171c609719bSwdenk- board/esd/cpciiser4	Files specific to CPCIISER4  boards
172c609719bSwdenk- board/esd/common	Common files for ESD boards
173c609719bSwdenk- board/esd/dasa_sim	Files specific to DASA_SIM   boards
174c609719bSwdenk- board/esd/du405	Files specific to DU405      boards
175c609719bSwdenk- board/esd/ocrtc	Files specific to OCRTC      boards
176c609719bSwdenk- board/esd/pci405	Files specific to PCI405     boards
177c609719bSwdenk- board/esteem192e
178c609719bSwdenk		Files specific to ESTEEM192E boards
179c609719bSwdenk- board/etx094	Files specific to ETX_094    boards
180c609719bSwdenk- board/evb64260
181c609719bSwdenk		Files specific to EVB64260   boards
182c609719bSwdenk- board/fads	Files specific to FADS	     boards
183c609719bSwdenk- board/flagadm Files specific to FLAGADM    boards
1847aa78614Swdenk- board/gen860t Files specific to GEN860T and GEN860T_SC    boards
185c609719bSwdenk- board/genietv Files specific to GENIETV    boards
186c609719bSwdenk- board/gth	Files specific to GTH	     boards
187c609719bSwdenk- board/hermes	Files specific to HERMES     boards
188c609719bSwdenk- board/hymod	Files specific to HYMOD	     boards
189c609719bSwdenk- board/icu862	Files specific to ICU862     boards
190c609719bSwdenk- board/ip860	Files specific to IP860	     boards
191c609719bSwdenk- board/iphase4539
192c609719bSwdenk		Files specific to Interphase4539 boards
193c609719bSwdenk- board/ivm	Files specific to IVMS8/IVML24 boards
194c609719bSwdenk- board/lantec	Files specific to LANTEC     boards
195c609719bSwdenk- board/lwmon	Files specific to LWMON	     boards
196c609719bSwdenk- board/mbx8xx	Files specific to MBX	     boards
197c609719bSwdenk- board/mpc8260ads
198c609719bSwdenk		Files specific to MMPC8260ADS boards
199c609719bSwdenk- board/mpl/	Files specific to boards manufactured by MPL
200c609719bSwdenk- board/mpl/common	Common files for MPL boards
201c609719bSwdenk- board/mpl/pip405	Files specific to PIP405     boards
202c609719bSwdenk- board/mpl/mip405	Files specific to MIP405     boards
203c609719bSwdenk- board/musenki	Files specific to MUSEKNI    boards
204c609719bSwdenk- board/mvs1	Files specific to MVS1       boards
205c609719bSwdenk- board/nx823   Files specific to NX823      boards
206c609719bSwdenk- board/oxc	Files specific to OXC        boards
207c609719bSwdenk- board/pcippc2	Files specific to PCIPPC2/PCIPPC6 boards
208c609719bSwdenk- board/pm826	Files specific to PM826      boards
209c609719bSwdenk- board/ppmc8260
210c609719bSwdenk		Files specific to PPMC8260   boards
211c609719bSwdenk- board/rpxsuper
212c609719bSwdenk		Files specific to RPXsuper   boards
213c609719bSwdenk- board/rsdproto
214c609719bSwdenk		Files specific to RSDproto   boards
215c609719bSwdenk- board/sandpoint
216c609719bSwdenk		Files specific to Sandpoint  boards
217c609719bSwdenk- board/sbc8260	Files specific to SBC8260    boards
218c609719bSwdenk- board/sacsng	Files specific to SACSng     boards
219c609719bSwdenk- board/siemens Files specific to boards manufactured by Siemens AG
220c609719bSwdenk- board/siemens/CCM	Files specific to CCM	     boards
221c609719bSwdenk- board/siemens/IAD210	Files specific to IAD210     boards
222c609719bSwdenk- board/siemens/SCM	Files specific to SCM        boards
223c609719bSwdenk- board/siemens/pcu_e	Files specific to PCU_E	     boards
224c609719bSwdenk- board/sixnet	Files specific to SIXNET     boards
225c609719bSwdenk- board/spd8xx	Files specific to SPD8xxTS   boards
226c609719bSwdenk- board/tqm8260 Files specific to TQM8260    boards
227c609719bSwdenk- board/tqm8xx	Files specific to TQM8xxL    boards
228c609719bSwdenk- board/w7o	Files specific to W7O        boards
229c609719bSwdenk- board/walnut405
230c609719bSwdenk		Files specific to Walnut405  boards
231c609719bSwdenk- board/westel/	Files specific to boards manufactured by Westel Wireless
232c609719bSwdenk- board/westel/amx860	Files specific to AMX860     boards
233c609719bSwdenk- board/utx8245	Files specific to UTX8245   boards
234c609719bSwdenk
235c609719bSwdenkSoftware Configuration:
236c609719bSwdenk=======================
237c609719bSwdenk
238c609719bSwdenkConfiguration is usually done using C preprocessor defines; the
239c609719bSwdenkrationale behind that is to avoid dead code whenever possible.
240c609719bSwdenk
241c609719bSwdenkThere are two classes of configuration variables:
242c609719bSwdenk
243c609719bSwdenk* Configuration _OPTIONS_:
244c609719bSwdenk  These are selectable by the user and have names beginning with
245c609719bSwdenk  "CONFIG_".
246c609719bSwdenk
247c609719bSwdenk* Configuration _SETTINGS_:
248c609719bSwdenk  These depend on the hardware etc. and should not be meddled with if
249c609719bSwdenk  you don't know what you're doing; they have names beginning with
250c609719bSwdenk  "CFG_".
251c609719bSwdenk
252c609719bSwdenkLater we will add a configuration tool - probably similar to or even
253c609719bSwdenkidentical to what's used for the Linux kernel. Right now, we have to
254c609719bSwdenkdo the configuration by hand, which means creating some symbolic
255c609719bSwdenklinks and editing some configuration files. We use the TQM8xxL boards
256c609719bSwdenkas an example here.
257c609719bSwdenk
258c609719bSwdenk
259c609719bSwdenkSelection of Processor Architecture and Board Type:
260c609719bSwdenk---------------------------------------------------
261c609719bSwdenk
262c609719bSwdenkFor all supported boards there are ready-to-use default
263c609719bSwdenkconfigurations available; just type "make <board_name>_config".
264c609719bSwdenk
265c609719bSwdenkExample: For a TQM823L module type:
266c609719bSwdenk
267c609719bSwdenk	cd u-boot
268c609719bSwdenk	make TQM823L_config
269c609719bSwdenk
270c609719bSwdenkFor the Cogent platform, you need to specify the cpu type as well;
271c609719bSwdenke.g. "make cogent_mpc8xx_config". And also configure the cogent
272c609719bSwdenkdirectory according to the instructions in cogent/README.
273c609719bSwdenk
274c609719bSwdenk
275c609719bSwdenkConfiguration Options:
276c609719bSwdenk----------------------
277c609719bSwdenk
278c609719bSwdenkConfiguration depends on the combination of board and CPU type; all
279c609719bSwdenksuch information is kept in a configuration file
280c609719bSwdenk"include/configs/<board_name>.h".
281c609719bSwdenk
282c609719bSwdenkExample: For a TQM823L module, all configuration settings are in
283c609719bSwdenk"include/configs/TQM823L.h".
284c609719bSwdenk
285c609719bSwdenk
2867f6c2cbcSwdenkMany of the options are named exactly as the corresponding Linux
2877f6c2cbcSwdenkkernel configuration options. The intention is to make it easier to
2887f6c2cbcSwdenkbuild a config tool - later.
2897f6c2cbcSwdenk
2907f6c2cbcSwdenk
291c609719bSwdenkThe following options need to be configured:
292c609719bSwdenk
293c609719bSwdenk- CPU Type:	Define exactly one of
294c609719bSwdenk
295c609719bSwdenk		PowerPC based CPUs:
296c609719bSwdenk		-------------------
297c609719bSwdenk		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860
2980db5bca8Swdenk	or	CONFIG_MPC5xx
299c609719bSwdenk	or	CONFIG_MPC824X, CONFIG_MPC8260
300c609719bSwdenk	or	CONFIG_IOP480
301c609719bSwdenk	or	CONFIG_405GP
302c609719bSwdenk	or	CONFIG_440
303c609719bSwdenk	or	CONFIG_MPC74xx
304c609719bSwdenk
305c609719bSwdenk		ARM based CPUs:
306c609719bSwdenk		---------------
307c609719bSwdenk		CONFIG_SA1110
308c609719bSwdenk		CONFIG_ARM7
309c609719bSwdenk		CONFIG_PXA250
310c609719bSwdenk
311c609719bSwdenk
312c609719bSwdenk- Board Type:	Define exactly one of
313c609719bSwdenk
314c609719bSwdenk		PowerPC based boards:
315c609719bSwdenk		---------------------
316c609719bSwdenk
317c609719bSwdenk		CONFIG_ADCIOP,     CONFIG_ICU862      CONFIG_RPXsuper,
318c609719bSwdenk		CONFIG_ADS860,     CONFIG_IP860,      CONFIG_SM850,
319c609719bSwdenk		CONFIG_AMX860,     CONFIG_IPHASE4539, CONFIG_SPD823TS,
320c609719bSwdenk		CONFIG_AR405,      CONFIG_IVML24,     CONFIG_SXNI855T,
321c609719bSwdenk		CONFIG_BAB7xx,     CONFIG_IVML24_128, CONFIG_Sandpoint8240,
322c609719bSwdenk		CONFIG_CANBT,      CONFIG_IVML24_256, CONFIG_Sandpoint8245,
323c609719bSwdenk		CONFIG_CCM,        CONFIG_IVMS8,      CONFIG_TQM823L,
324c609719bSwdenk		CONFIG_CPCI405,    CONFIG_IVMS8_128,  CONFIG_TQM850L,
325c609719bSwdenk		CONFIG_CPCI4052,   CONFIG_IVMS8_256,  CONFIG_TQM855L,
326c609719bSwdenk		CONFIG_CPCIISER4,  CONFIG_LANTEC,     CONFIG_TQM860L,
327c609719bSwdenk		CONFIG_CPU86,      CONFIG_MBX,        CONFIG_TQM8260,
328c609719bSwdenk		CONFIG_CRAYL1,     CONFIG_MBX860T,    CONFIG_TTTech,
329c609719bSwdenk		CONFIG_CU824,      CONFIG_MHPC,       CONFIG_UTX8245,
330c609719bSwdenk		CONFIG_DASA_SIM,   CONFIG_MIP405,     CONFIG_W7OLMC,
331c609719bSwdenk		CONFIG_DU405,      CONFIG_MOUSSE,     CONFIG_W7OLMG,
332c609719bSwdenk		CONFIG_ELPPC,      CONFIG_MPC8260ADS, CONFIG_WALNUT405,
333c609719bSwdenk		CONFIG_ERIC,       CONFIG_MUSENKI,    CONFIG_ZUMA,
334c609719bSwdenk		CONFIG_ESTEEM192E, CONFIG_MVS1,       CONFIG_c2mon,
335c609719bSwdenk		CONFIG_ETX094,     CONFIG_NX823,      CONFIG_cogent_mpc8260,
336c609719bSwdenk		CONFIG_EVB64260,   CONFIG_OCRTC,      CONFIG_cogent_mpc8xx,
337c609719bSwdenk		CONFIG_FADS823,    CONFIG_ORSG,       CONFIG_ep8260,
338c609719bSwdenk		CONFIG_FADS850SAR, CONFIG_OXC,        CONFIG_gw8260,
339c609719bSwdenk		CONFIG_FADS860T,   CONFIG_PCI405,     CONFIG_hermes,
340c609719bSwdenk		CONFIG_FLAGADM,    CONFIG_PCIPPC2,    CONFIG_hymod,
341c609719bSwdenk		CONFIG_FPS850L,    CONFIG_PCIPPC6,    CONFIG_lwmon,
342c609719bSwdenk		CONFIG_GEN860T,    CONFIG_PIP405,     CONFIG_pcu_e,
343c609719bSwdenk		CONFIG_GENIETV,    CONFIG_PM826,      CONFIG_ppmc8260,
344c609719bSwdenk		CONFIG_GTH,        CONFIG_RPXClassic, CONFIG_rsdproto,
345c609719bSwdenk		CONFIG_IAD210,     CONFIG_RPXlite,    CONFIG_sbc8260,
346608c9146Swdenk		CONFIG_EBONY,      CONFIG_sacsng,     CONFIG_FPS860L,
3477f70e853Swdenk		CONFIG_V37,        CONFIG_ELPT860,    CONFIG_CMI,
348682011ffSwdenk		CONFIG_NETVIA,     CONFIG_RBC823
349c609719bSwdenk
350c609719bSwdenk		ARM based boards:
351c609719bSwdenk		-----------------
352c609719bSwdenk
353c609719bSwdenk		CONFIG_HHP_CRADLE,  CONFIG_DNP1110,    CONFIG_EP7312,
354c609719bSwdenk		CONFIG_IMPA7,       CONFIG_LART,       CONFIG_LUBBOCK,
355c609719bSwdenk		CONFIG_SHANNON,     CONFIG_SMDK2400,   CONFIG_SMDK2410,
3562abbe075Swdenk		CONFIG_TRAB,	    CONFIG_AT91RM9200DK
357c609719bSwdenk
358c609719bSwdenk
359c609719bSwdenk- CPU Module Type: (if CONFIG_COGENT is defined)
360c609719bSwdenk		Define exactly one of
361c609719bSwdenk		CONFIG_CMA286_60_OLD
362c609719bSwdenk--- FIXME --- not tested yet:
363c609719bSwdenk		CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
364c609719bSwdenk		CONFIG_CMA287_23, CONFIG_CMA287_50
365c609719bSwdenk
366c609719bSwdenk- Motherboard Type: (if CONFIG_COGENT is defined)
367c609719bSwdenk		Define exactly one of
368c609719bSwdenk		CONFIG_CMA101, CONFIG_CMA102
369c609719bSwdenk
370c609719bSwdenk- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
371c609719bSwdenk		Define one or more of
372c609719bSwdenk		CONFIG_CMA302
373c609719bSwdenk
374c609719bSwdenk- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
375c609719bSwdenk		Define one or more of
376c609719bSwdenk		CONFIG_LCD_HEARTBEAT	- update a character position on
377c609719bSwdenk					  the lcd display every second with
378c609719bSwdenk					  a "rotator" |\-/|\-/
379c609719bSwdenk
380c609719bSwdenk- MPC824X Family Member (if CONFIG_MPC824X is defined)
381c609719bSwdenk	Define exactly one of
382c609719bSwdenk	CONFIG_MPC8240, CONFIG_MPC8245
383c609719bSwdenk
384c609719bSwdenk- 8xx CPU Options: (if using an 8xx cpu)
385c609719bSwdenk		Define one or more of
386c609719bSwdenk		CONFIG_8xx_GCLK_FREQ	- if get_gclk_freq() can not work e.g.
387c609719bSwdenk					  no 32KHz reference PIT/RTC clock
388c609719bSwdenk
389c609719bSwdenk- Clock Interface:
390c609719bSwdenk		CONFIG_CLOCKS_IN_MHZ
391c609719bSwdenk
392c609719bSwdenk		U-Boot stores all clock information in Hz
393c609719bSwdenk		internally. For binary compatibility with older Linux
394c609719bSwdenk		kernels (which expect the clocks passed in the
395c609719bSwdenk		bd_info data to be in MHz) the environment variable
396c609719bSwdenk		"clocks_in_mhz" can be defined so that U-Boot
397c609719bSwdenk		converts clock data to MHZ before passing it to the
398c609719bSwdenk		Linux kernel.
399c609719bSwdenk
400c609719bSwdenk		When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
401c609719bSwdenk		"clocks_in_mhz=1" is  automatically  included  in  the
402c609719bSwdenk		default environment.
403c609719bSwdenk
404c609719bSwdenk- Console Interface:
405c609719bSwdenk		Depending on board, define exactly one serial port
406c609719bSwdenk		(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
407c609719bSwdenk		CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
408c609719bSwdenk		console by defining CONFIG_8xx_CONS_NONE
409c609719bSwdenk
410c609719bSwdenk		Note: if CONFIG_8xx_CONS_NONE is defined, the serial
411c609719bSwdenk		port routines must be defined elsewhere
412c609719bSwdenk		(i.e. serial_init(), serial_getc(), ...)
413c609719bSwdenk
414c609719bSwdenk		CONFIG_CFB_CONSOLE
415c609719bSwdenk		Enables console device for a color framebuffer. Needs following
416c609719bSwdenk		defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
417c609719bSwdenk			VIDEO_FB_LITTLE_ENDIAN	graphic memory organisation
418c609719bSwdenk						(default big endian)
419c609719bSwdenk			VIDEO_HW_RECTFILL	graphic chip supports
420c609719bSwdenk						rectangle fill
421c609719bSwdenk						(cf. smiLynxEM)
422c609719bSwdenk			VIDEO_HW_BITBLT		graphic chip supports
423c609719bSwdenk						bit-blit (cf. smiLynxEM)
424c609719bSwdenk			VIDEO_VISIBLE_COLS	visible pixel columns
425c609719bSwdenk						(cols=pitch)
426c609719bSwdenk			VIDEO_VISIBLE_ROWS      visible pixel rows
427c609719bSwdenk			VIDEO_PIXEL_SIZE        bytes per pixel
428c609719bSwdenk			VIDEO_DATA_FORMAT	graphic data format
429c609719bSwdenk						(0-5, cf. cfb_console.c)
430c609719bSwdenk			VIDEO_FB_ADRS           framebuffer address
431c609719bSwdenk			VIDEO_KBD_INIT_FCT	keyboard int fct
432c609719bSwdenk						(i.e. i8042_kbd_init())
433c609719bSwdenk			VIDEO_TSTC_FCT		test char fct
434c609719bSwdenk						(i.e. i8042_tstc)
435c609719bSwdenk			VIDEO_GETC_FCT		get char fct
436c609719bSwdenk						(i.e. i8042_getc)
437c609719bSwdenk			CONFIG_CONSOLE_CURSOR	cursor drawing on/off
438c609719bSwdenk						(requires blink timer
439c609719bSwdenk						cf. i8042.c)
440c609719bSwdenk			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
441c609719bSwdenk			CONFIG_CONSOLE_TIME	display time/date info in
442c609719bSwdenk						upper right corner
443c609719bSwdenk						(requires CFG_CMD_DATE)
444c609719bSwdenk			CONFIG_VIDEO_LOGO	display Linux logo in
445c609719bSwdenk						upper left corner
446a6c7ad2fSwdenk			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of
447a6c7ad2fSwdenk						linux_logo.h for logo.
448a6c7ad2fSwdenk						Requires CONFIG_VIDEO_LOGO
449c609719bSwdenk			CONFIG_CONSOLE_EXTRA_INFO
450c609719bSwdenk						addional board info beside
451c609719bSwdenk						the logo
452c609719bSwdenk
453c609719bSwdenk		When CONFIG_CFB_CONSOLE is defined, video console is
454c609719bSwdenk		default i/o. Serial console can be forced with
455c609719bSwdenk		environment 'console=serial'.
456c609719bSwdenk
457c609719bSwdenk- Console Baudrate:
458c609719bSwdenk		CONFIG_BAUDRATE - in bps
459c609719bSwdenk		Select one of the baudrates listed in
460c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
461c609719bSwdenk
462c609719bSwdenk- Interrupt driven serial port input:
463c609719bSwdenk		CONFIG_SERIAL_SOFTWARE_FIFO
464c609719bSwdenk
465c609719bSwdenk		PPC405GP only.
466c609719bSwdenk		Use an interrupt handler for receiving data on the
467c609719bSwdenk		serial port. It also enables using hardware handshake
468c609719bSwdenk		(RTS/CTS) and UART's built-in FIFO. Set the number of
469c609719bSwdenk		bytes the interrupt driven input buffer should have.
470c609719bSwdenk
471c609719bSwdenk		Set to 0 to disable this feature (this is the default).
472c609719bSwdenk		This will also disable hardware handshake.
473c609719bSwdenk
4741d49b1f3Sstroese- Console UART Number:
4751d49b1f3Sstroese		CONFIG_UART1_CONSOLE
4761d49b1f3Sstroese
4771d49b1f3Sstroese		IBM PPC4xx only.
4781d49b1f3Sstroese		If defined internal UART1 (and not UART0) is used
4791d49b1f3Sstroese		as default U-Boot console.
4801d49b1f3Sstroese
481c609719bSwdenk- Boot Delay:	CONFIG_BOOTDELAY - in seconds
482c609719bSwdenk		Delay before automatically booting the default image;
483c609719bSwdenk		set to -1 to disable autoboot.
484c609719bSwdenk
485c609719bSwdenk		See doc/README.autoboot for these options that
486c609719bSwdenk		work with CONFIG_BOOTDELAY. None are required.
487c609719bSwdenk		CONFIG_BOOT_RETRY_TIME
488c609719bSwdenk		CONFIG_BOOT_RETRY_MIN
489c609719bSwdenk		CONFIG_AUTOBOOT_KEYED
490c609719bSwdenk		CONFIG_AUTOBOOT_PROMPT
491c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR
492c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR
493c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR2
494c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR2
495c609719bSwdenk		CONFIG_ZERO_BOOTDELAY_CHECK
496c609719bSwdenk		CONFIG_RESET_TO_RETRY
497c609719bSwdenk
498c609719bSwdenk- Autoboot Command:
499c609719bSwdenk		CONFIG_BOOTCOMMAND
500c609719bSwdenk		Only needed when CONFIG_BOOTDELAY is enabled;
501c609719bSwdenk		define a command string that is automatically executed
502c609719bSwdenk		when no character is read on the console interface
503c609719bSwdenk		within "Boot Delay" after reset.
504c609719bSwdenk
505c609719bSwdenk		CONFIG_BOOTARGS
506c609719bSwdenk		This can be used to pass arguments to the bootm
507c609719bSwdenk		command. The value of CONFIG_BOOTARGS goes into the
508c609719bSwdenk		environment value "bootargs".
509c609719bSwdenk
510c609719bSwdenk		CONFIG_RAMBOOT and CONFIG_NFSBOOT
511c609719bSwdenk		The value of these goes into the environment as
512c609719bSwdenk		"ramboot" and "nfsboot" respectively, and can be used
513c609719bSwdenk		as a convenience, when switching between booting from
514c609719bSwdenk		ram and nfs.
515c609719bSwdenk
516c609719bSwdenk- Pre-Boot Commands:
517c609719bSwdenk		CONFIG_PREBOOT
518c609719bSwdenk
519c609719bSwdenk		When this option is #defined, the existence of the
520c609719bSwdenk		environment variable "preboot" will be checked
521c609719bSwdenk		immediately before starting the CONFIG_BOOTDELAY
522c609719bSwdenk		countdown and/or running the auto-boot command resp.
523c609719bSwdenk		entering interactive mode.
524c609719bSwdenk
525c609719bSwdenk		This feature is especially useful when "preboot" is
526c609719bSwdenk		automatically generated or modified. For an example
527c609719bSwdenk		see the LWMON board specific code: here "preboot" is
528c609719bSwdenk		modified when the user holds down a certain
529c609719bSwdenk		combination of keys on the (special) keyboard when
530c609719bSwdenk		booting the systems
531c609719bSwdenk
532c609719bSwdenk- Serial Download Echo Mode:
533c609719bSwdenk		CONFIG_LOADS_ECHO
534c609719bSwdenk		If defined to 1, all characters received during a
535c609719bSwdenk		serial download (using the "loads" command) are
536c609719bSwdenk		echoed back. This might be needed by some terminal
537c609719bSwdenk		emulations (like "cu"), but may as well just take
538c609719bSwdenk		time on others. This setting #define's the initial
539c609719bSwdenk		value of the "loads_echo" environment variable.
540c609719bSwdenk
541c609719bSwdenk- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
542c609719bSwdenk		CONFIG_KGDB_BAUDRATE
543c609719bSwdenk		Select one of the baudrates listed in
544c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
545c609719bSwdenk
546c609719bSwdenk- Monitor Functions:
547c609719bSwdenk		CONFIG_COMMANDS
548c609719bSwdenk		Most monitor functions can be selected (or
549c609719bSwdenk		de-selected) by adjusting the definition of
550c609719bSwdenk		CONFIG_COMMANDS; to select individual functions,
551c609719bSwdenk		#define CONFIG_COMMANDS by "OR"ing any of the
552c609719bSwdenk		following values:
553c609719bSwdenk
554c609719bSwdenk		#define enables commands:
555c609719bSwdenk		-------------------------
556c609719bSwdenk		CFG_CMD_ASKENV	* ask for env variable
557c609719bSwdenk		CFG_CMD_BDI	  bdinfo
558c609719bSwdenk		CFG_CMD_BEDBUG	  Include BedBug Debugger
559c609719bSwdenk		CFG_CMD_BOOTD	  bootd
560c609719bSwdenk		CFG_CMD_CACHE	  icache, dcache
561c609719bSwdenk		CFG_CMD_CONSOLE	  coninfo
562c609719bSwdenk		CFG_CMD_DATE	* support for RTC, date/time...
563c609719bSwdenk		CFG_CMD_DHCP	  DHCP support
564c609719bSwdenk		CFG_CMD_ECHO	* echo arguments
565c609719bSwdenk		CFG_CMD_EEPROM	* EEPROM read/write support
566c609719bSwdenk		CFG_CMD_ELF	  bootelf, bootvx
567c609719bSwdenk		CFG_CMD_ENV	  saveenv
568c609719bSwdenk		CFG_CMD_FDC	* Floppy Disk Support
56971f95118Swdenk		CFG_CMD_FAT	  FAT partition support
5702262cfeeSwdenk		CFG_CMD_FDOS	* Dos diskette Support
571c609719bSwdenk		CFG_CMD_FLASH	  flinfo, erase, protect
572c609719bSwdenk		CFG_CMD_FPGA	  FPGA device initialization support
573c609719bSwdenk		CFG_CMD_I2C	* I2C serial bus support
574c609719bSwdenk		CFG_CMD_IDE	* IDE harddisk support
575c609719bSwdenk		CFG_CMD_IMI	  iminfo
576c609719bSwdenk		CFG_CMD_IMMAP	* IMMR dump support
577c609719bSwdenk		CFG_CMD_IRQ	* irqinfo
578c609719bSwdenk		CFG_CMD_KGDB	* kgdb
579c609719bSwdenk		CFG_CMD_LOADB	  loadb
580c609719bSwdenk		CFG_CMD_LOADS	  loads
581c609719bSwdenk		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
582c609719bSwdenk				  loop, mtest
58371f95118Swdenk		CFG_CMD_MMC	  MMC memory mapped support
584c609719bSwdenk		CFG_CMD_MII	  MII utility commands
585c609719bSwdenk		CFG_CMD_NET	  bootp, tftpboot, rarpboot
586c609719bSwdenk		CFG_CMD_PCI	* pciinfo
587c609719bSwdenk		CFG_CMD_PCMCIA	* PCMCIA support
588c609719bSwdenk		CFG_CMD_REGINFO * Register dump
589c609719bSwdenk		CFG_CMD_RUN	  run command in env variable
590c609719bSwdenk		CFG_CMD_SCSI	* SCSI Support
591c609719bSwdenk		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
592c609719bSwdenk		CFG_CMD_SPI	* SPI serial bus support
593c609719bSwdenk		CFG_CMD_USB	* USB support
594c609719bSwdenk		CFG_CMD_BSP	* Board SPecific functions
595c609719bSwdenk		-----------------------------------------------
596c609719bSwdenk		CFG_CMD_ALL	all
597c609719bSwdenk
598c609719bSwdenk		CFG_CMD_DFL	Default configuration; at the moment
599c609719bSwdenk				this is includes all commands, except
600c609719bSwdenk				the ones marked with "*" in the list
601c609719bSwdenk				above.
602c609719bSwdenk
603c609719bSwdenk		If you don't define CONFIG_COMMANDS it defaults to
604c609719bSwdenk		CFG_CMD_DFL in include/cmd_confdefs.h. A board can
605c609719bSwdenk		override the default settings in the respective
606c609719bSwdenk		include file.
607c609719bSwdenk
608c609719bSwdenk		EXAMPLE: If you want all functions except of network
609c609719bSwdenk		support you can write:
610c609719bSwdenk
611c609719bSwdenk		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
612c609719bSwdenk
613c609719bSwdenk
614c609719bSwdenk	Note:	Don't enable the "icache" and "dcache" commands
615c609719bSwdenk		(configuration option CFG_CMD_CACHE) unless you know
616c609719bSwdenk		what you (and your U-Boot users) are doing. Data
617c609719bSwdenk		cache cannot be enabled on systems like the 8xx or
618c609719bSwdenk		8260 (where accesses to the IMMR region must be
619c609719bSwdenk		uncached), and it cannot be disabled on all other
620c609719bSwdenk		systems where we (mis-) use the data cache to hold an
621c609719bSwdenk		initial stack and some data.
622c609719bSwdenk
623c609719bSwdenk
624c609719bSwdenk		XXX - this list needs to get updated!
625c609719bSwdenk
626c609719bSwdenk- Watchdog:
627c609719bSwdenk		CONFIG_WATCHDOG
628c609719bSwdenk		If this variable is defined, it enables watchdog
629c609719bSwdenk		support. There must support in the platform specific
630c609719bSwdenk		code for a watchdog. For the 8xx and 8260 CPUs, the
631c609719bSwdenk		SIU Watchdog feature is enabled in the SYPCR
632c609719bSwdenk		register.
633c609719bSwdenk
634c1551ea8Sstroese- U-Boot Version:
635c1551ea8Sstroese		CONFIG_VERSION_VARIABLE
636c1551ea8Sstroese		If this variable is defined, an environment variable
637c1551ea8Sstroese		named "ver" is created by U-Boot showing the U-Boot
638c1551ea8Sstroese		version as printed by the "version" command.
639c1551ea8Sstroese		This variable is readonly.
640c1551ea8Sstroese
641c609719bSwdenk- Real-Time Clock:
642c609719bSwdenk
643c609719bSwdenk		When CFG_CMD_DATE is selected, the type of the RTC
644c609719bSwdenk		has to be selected, too. Define exactly one of the
645c609719bSwdenk		following options:
646c609719bSwdenk
647c609719bSwdenk		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx
648c609719bSwdenk		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC
649c609719bSwdenk		CONFIG_RTC_MC146818	- use MC146818 RTC
6501cb8e980Swdenk		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
651c609719bSwdenk		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
6527f70e853Swdenk		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
6533bac3513Swdenk		CONFIG_RTC_DS164x	- use Dallas DS164x RTC
654c609719bSwdenk
655c609719bSwdenk- Timestamp Support:
656c609719bSwdenk
657c609719bSwdenk		When CONFIG_TIMESTAMP is selected, the timestamp
658c609719bSwdenk		(date and time) of an image is printed by image
659c609719bSwdenk		commands like bootm or iminfo. This option is
660c609719bSwdenk		automatically enabled when you select CFG_CMD_DATE .
661c609719bSwdenk
662c609719bSwdenk- Partition Support:
663c609719bSwdenk		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
664c609719bSwdenk		and/or CONFIG_ISO_PARTITION
665c609719bSwdenk
666c609719bSwdenk		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or
667c609719bSwdenk		CFG_CMD_SCSI) you must configure support for at least
668c609719bSwdenk		one partition type as well.
669c609719bSwdenk
670c609719bSwdenk- IDE Reset method:
671c609719bSwdenk		CONFIG_IDE_RESET_ROUTINE
672c609719bSwdenk
673c609719bSwdenk		Set this to define that instead of a reset Pin, the
674c609719bSwdenk		routine ide_set_reset(int idereset) will be used.
675c609719bSwdenk
676c609719bSwdenk- ATAPI Support:
677c609719bSwdenk		CONFIG_ATAPI
678c609719bSwdenk
679c609719bSwdenk		Set this to enable ATAPI support.
680c609719bSwdenk
681c609719bSwdenk- SCSI Support:
682c609719bSwdenk		At the moment only there is only support for the
683c609719bSwdenk		SYM53C8XX SCSI controller; define
684c609719bSwdenk		CONFIG_SCSI_SYM53C8XX to enable it.
685c609719bSwdenk
686c609719bSwdenk		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
687c609719bSwdenk		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
688c609719bSwdenk		CFG_SCSI_MAX_LUN] can be adjusted to define the
689c609719bSwdenk		maximum numbers of LUNs, SCSI ID's and target
690c609719bSwdenk		devices.
691c609719bSwdenk		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
692c609719bSwdenk
693c609719bSwdenk- NETWORK Support (PCI):
694682011ffSwdenk		CONFIG_E1000
695682011ffSwdenk		Support for Intel 8254x gigabit chips.
696682011ffSwdenk
697c609719bSwdenk		CONFIG_EEPRO100
698c609719bSwdenk		Support for Intel 82557/82559/82559ER chips.
699c609719bSwdenk		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
700c609719bSwdenk		write routine for first time initialisation.
701c609719bSwdenk
702c609719bSwdenk		CONFIG_TULIP
703c609719bSwdenk		Support for Digital 2114x chips.
704c609719bSwdenk		Optional CONFIG_TULIP_SELECT_MEDIA for board specific
705c609719bSwdenk		modem chip initialisation (KS8761/QS6611).
706c609719bSwdenk
707c609719bSwdenk		CONFIG_NATSEMI
708c609719bSwdenk		Support for National dp83815 chips.
709c609719bSwdenk
710c609719bSwdenk		CONFIG_NS8382X
711c609719bSwdenk		Support for National dp8382[01] gigabit chips.
712c609719bSwdenk
71345219c46Swdenk- NETWORK Support (other):
71445219c46Swdenk
71545219c46Swdenk		CONFIG_DRIVER_LAN91C96
71645219c46Swdenk		Support for SMSC's LAN91C96 chips.
71745219c46Swdenk
71845219c46Swdenk			CONFIG_LAN91C96_BASE
71945219c46Swdenk			Define this to hold the physical address
72045219c46Swdenk			of the LAN91C96's I/O space
72145219c46Swdenk
72245219c46Swdenk			CONFIG_LAN91C96_USE_32_BIT
72345219c46Swdenk			Define this to enable 32 bit addressing
72445219c46Swdenk
725c609719bSwdenk- USB Support:
726c609719bSwdenk		At the moment only the UHCI host controller is
727c609719bSwdenk		supported (PIP405, MIP405); define
728c609719bSwdenk		CONFIG_USB_UHCI to enable it.
729c609719bSwdenk		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
730c609719bSwdenk		end define CONFIG_USB_STORAGE to enable the USB
731c609719bSwdenk		storage devices.
732c609719bSwdenk		Note:
733c609719bSwdenk		Supported are USB Keyboards and USB Floppy drives
734c609719bSwdenk		(TEAC FD-05PUB).
735c609719bSwdenk
73671f95118Swdenk- MMC Support:
73771f95118Swdenk  		The MMC controller on the Intel PXA is supported. To
73871f95118Swdenk		enable this define CONFIG_MMC. The MMC can be
73971f95118Swdenk		accessed from the boot prompt by mapping the device
74071f95118Swdenk		to physical memory similar to flash. Command line is
74171f95118Swdenk		enabled with CFG_CMD_MMC. The MMC driver also works with
74271f95118Swdenk		the FAT fs. This is enabled with CFG_CMD_FAT.
74371f95118Swdenk
744c609719bSwdenk- Keyboard Support:
745c609719bSwdenk		CONFIG_ISA_KEYBOARD
746c609719bSwdenk
747c609719bSwdenk		Define this to enable standard (PC-Style) keyboard
748c609719bSwdenk		support
749c609719bSwdenk
750c609719bSwdenk		CONFIG_I8042_KBD
751c609719bSwdenk		Standard PC keyboard driver with US (is default) and
752c609719bSwdenk		GERMAN key layout (switch via environment 'keymap=de') support.
753c609719bSwdenk		Export function i8042_kbd_init, i8042_tstc and i8042_getc
754c609719bSwdenk		for cfb_console. Supports cursor blinking.
755c609719bSwdenk
756c609719bSwdenk- Video support:
757c609719bSwdenk		CONFIG_VIDEO
758c609719bSwdenk
759c609719bSwdenk		Define this to enable video support (for output to
760c609719bSwdenk		video).
761c609719bSwdenk
762c609719bSwdenk		CONFIG_VIDEO_CT69000
763c609719bSwdenk
764c609719bSwdenk		Enable Chips & Technologies 69000 Video chip
765c609719bSwdenk
766c609719bSwdenk		CONFIG_VIDEO_SMI_LYNXEM
767c609719bSwdenk		Enable Silicon Motion SMI 712/710/810 Video chip
768c609719bSwdenk		Videomode are selected via environment 'videomode' with
769c609719bSwdenk		standard LiLo mode numbers.
770c609719bSwdenk		Following modes are supported  (* is default):
771c609719bSwdenk
772c609719bSwdenk			    800x600  1024x768  1280x1024
773c609719bSwdenk	      256  (8bit)     303*      305       307
774c609719bSwdenk	    65536 (16bit)     314       317       31a
775c609719bSwdenk	16,7 Mill (24bit)     315       318       31b
776c609719bSwdenk		(i.e. setenv videomode 317; saveenv; reset;)
777c609719bSwdenk
778a6c7ad2fSwdenk		CONFIG_VIDEO_SED13806
779a6c7ad2fSwdenk		Enable Epson SED13806 driver. This driver supports 8bpp
780a6c7ad2fSwdenk		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
781a6c7ad2fSwdenk		or CONFIG_VIDEO_SED13806_16BPP
782a6c7ad2fSwdenk
783682011ffSwdenk- Keyboard Support:
784682011ffSwdenk                CONFIG_KEYBOARD
785682011ffSwdenk
786682011ffSwdenk                Define this to enable a custom keyboard support.
787682011ffSwdenk                This simply calls drv_keyboard_init() which must be
788682011ffSwdenk                defined in your board-specific files.
789682011ffSwdenk                The only board using this so far is RBC823.
790a6c7ad2fSwdenk
791c609719bSwdenk- LCD Support:	CONFIG_LCD
792c609719bSwdenk
793c609719bSwdenk		Define this to enable LCD support (for output to LCD
794c609719bSwdenk		display); also select one of the supported displays
795c609719bSwdenk		by defining one of these:
796c609719bSwdenk
797c609719bSwdenk		CONFIG_NEC_NL6648AC33:
798c609719bSwdenk
799c609719bSwdenk			NEC NL6648AC33-18. Active, color, single scan.
800c609719bSwdenk
801c609719bSwdenk		CONFIG_NEC_NL6648BC20
802c609719bSwdenk
803c609719bSwdenk			NEC NL6648BC20-08. 6.5", 640x480.
804c609719bSwdenk			Active, color, single scan.
805c609719bSwdenk
806c609719bSwdenk		CONFIG_SHARP_16x9
807c609719bSwdenk
808c609719bSwdenk			Sharp 320x240. Active, color, single scan.
809c609719bSwdenk			It isn't 16x9, and I am not sure what it is.
810c609719bSwdenk
811c609719bSwdenk		CONFIG_SHARP_LQ64D341
812c609719bSwdenk
813c609719bSwdenk			Sharp LQ64D341 display, 640x480.
814c609719bSwdenk			Active, color, single scan.
815c609719bSwdenk
816c609719bSwdenk		CONFIG_HLD1045
817c609719bSwdenk
818c609719bSwdenk			HLD1045 display, 640x480.
819c609719bSwdenk			Active, color, single scan.
820c609719bSwdenk
821c609719bSwdenk		CONFIG_OPTREX_BW
822c609719bSwdenk
823c609719bSwdenk			Optrex	 CBL50840-2 NF-FW 99 22 M5
824c609719bSwdenk			or
825c609719bSwdenk			Hitachi	 LMG6912RPFC-00T
826c609719bSwdenk			or
827c609719bSwdenk			Hitachi	 SP14Q002
828c609719bSwdenk
829c609719bSwdenk			320x240. Black & white.
830c609719bSwdenk
831c609719bSwdenk		Normally display is black on white background; define
832c609719bSwdenk		CFG_WHITE_ON_BLACK to get it inverted.
833c609719bSwdenk
834d791b1dcSwdenk- Spash Screen Support: CONFIG_SPLASH_SCREEN
835d791b1dcSwdenk
836d791b1dcSwdenk                If this option is set, the environment is checked for
837d791b1dcSwdenk                a variable "splashimage". If found, the usual display
838d791b1dcSwdenk                of logo, copyright and system information on the LCD
839d791b1dcSwdenk                is supressed and the BMP image at the address
840d791b1dcSwdenk                specified in "splashimage" is loaded instead. The
841d791b1dcSwdenk                console is redirected to the "nulldev", too. This
842d791b1dcSwdenk                allows for a "silent" boot where a splash screen is
843d791b1dcSwdenk                loaded very quickly after power-on.
844d791b1dcSwdenk
845d791b1dcSwdenk
846c609719bSwdenk- Ethernet address:
847c609719bSwdenk		CONFIG_ETHADDR
848c609719bSwdenk		CONFIG_ETH2ADDR
849c609719bSwdenk		CONFIG_ETH3ADDR
850c609719bSwdenk
851c609719bSwdenk		Define a default value for ethernet address to use
852c609719bSwdenk		for the respective ethernet interface, in case this
853c609719bSwdenk		is not determined automatically.
854c609719bSwdenk
855c609719bSwdenk- IP address:
856c609719bSwdenk		CONFIG_IPADDR
857c609719bSwdenk
858c609719bSwdenk		Define a default value for the IP address to use for
859c609719bSwdenk		the default ethernet interface, in case this is not
860c609719bSwdenk		determined through e.g. bootp.
861c609719bSwdenk
862c609719bSwdenk- Server IP address:
863c609719bSwdenk		CONFIG_SERVERIP
864c609719bSwdenk
865c609719bSwdenk		Defines a default value for theIP address of a TFTP
866c609719bSwdenk		server to contact when using the "tftboot" command.
867c609719bSwdenk
868c609719bSwdenk- BOOTP Recovery Mode:
869c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY
870c609719bSwdenk
871c609719bSwdenk		If you have many targets in a network that try to
872c609719bSwdenk		boot using BOOTP, you may want to avoid that all
873c609719bSwdenk		systems send out BOOTP requests at precisely the same
874c609719bSwdenk		moment (which would happen for instance at recovery
875c609719bSwdenk		from a power failure, when all systems will try to
876c609719bSwdenk		boot, thus flooding the BOOTP server. Defining
877c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
878c609719bSwdenk		inserted before sending out BOOTP requests. The
879c609719bSwdenk		following delays are insterted then:
880c609719bSwdenk
881c609719bSwdenk		1st BOOTP request:	delay 0 ... 1 sec
882c609719bSwdenk		2nd BOOTP request:	delay 0 ... 2 sec
883c609719bSwdenk		3rd BOOTP request:	delay 0 ... 4 sec
884c609719bSwdenk		4th and following
885c609719bSwdenk		BOOTP requests:		delay 0 ... 8 sec
886c609719bSwdenk
887c609719bSwdenk- Status LED:	CONFIG_STATUS_LED
888c609719bSwdenk
889c609719bSwdenk		Several configurations allow to display the current
890c609719bSwdenk		status using a LED. For instance, the LED will blink
891c609719bSwdenk		fast while running U-Boot code, stop blinking as
892c609719bSwdenk		soon as a reply to a BOOTP request was received, and
893c609719bSwdenk		start blinking slow once the Linux kernel is running
894c609719bSwdenk		(supported by a status LED driver in the Linux
895c609719bSwdenk		kernel). Defining CONFIG_STATUS_LED enables this
896c609719bSwdenk		feature in U-Boot.
897c609719bSwdenk
898c609719bSwdenk- CAN Support:	CONFIG_CAN_DRIVER
899c609719bSwdenk
900c609719bSwdenk		Defining CONFIG_CAN_DRIVER enables CAN driver support
901c609719bSwdenk		on those systems that support this (optional)
902c609719bSwdenk		feature, like the TQM8xxL modules.
903c609719bSwdenk
904c609719bSwdenk- I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C
905c609719bSwdenk
906c609719bSwdenk		Enables I2C serial bus commands.  If this is selected,
907c609719bSwdenk		either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
908c609719bSwdenk		to include the appropriate I2C driver.
909c609719bSwdenk
910c609719bSwdenk		See also: common/cmd_i2c.c for a description of the
911c609719bSwdenk		command line interface.
912c609719bSwdenk
913c609719bSwdenk
914c609719bSwdenk		CONFIG_HARD_I2C
915c609719bSwdenk
916c609719bSwdenk		Selects the CPM hardware driver for I2C.
917c609719bSwdenk
918c609719bSwdenk		CONFIG_SOFT_I2C
919c609719bSwdenk
920c609719bSwdenk		Use software (aka bit-banging) driver instead of CPM
921c609719bSwdenk		or similar hardware support for I2C.  This is configured
922c609719bSwdenk		via the following defines.
923c609719bSwdenk
924c609719bSwdenk		I2C_INIT
925c609719bSwdenk
926c609719bSwdenk		(Optional). Any commands necessary to enable I2C
927c609719bSwdenk		controller or configure ports.
928c609719bSwdenk
929c609719bSwdenk		I2C_PORT
930c609719bSwdenk
931c609719bSwdenk		(Only for MPC8260 CPU). The I/O port to use (the code
932c609719bSwdenk		assumes both bits are on the same port). Valid values
933c609719bSwdenk		are 0..3 for ports A..D.
934c609719bSwdenk
935c609719bSwdenk		I2C_ACTIVE
936c609719bSwdenk
937c609719bSwdenk		The code necessary to make the I2C data line active
938c609719bSwdenk		(driven).  If the data line is open collector, this
939c609719bSwdenk		define can be null.
940c609719bSwdenk
941c609719bSwdenk		I2C_TRISTATE
942c609719bSwdenk
943c609719bSwdenk		The code necessary to make the I2C data line tri-stated
944c609719bSwdenk		(inactive).  If the data line is open collector, this
945c609719bSwdenk		define can be null.
946c609719bSwdenk
947c609719bSwdenk		I2C_READ
948c609719bSwdenk
949c609719bSwdenk		Code that returns TRUE if the I2C data line is high,
950c609719bSwdenk		FALSE if it is low.
951c609719bSwdenk
952c609719bSwdenk		I2C_SDA(bit)
953c609719bSwdenk
954c609719bSwdenk		If <bit> is TRUE, sets the I2C data line high. If it
955c609719bSwdenk		is FALSE, it clears it (low).
956c609719bSwdenk
957c609719bSwdenk		I2C_SCL(bit)
958c609719bSwdenk
959c609719bSwdenk		If <bit> is TRUE, sets the I2C clock line high. If it
960c609719bSwdenk		is FALSE, it clears it (low).
961c609719bSwdenk
962c609719bSwdenk		I2C_DELAY
963c609719bSwdenk
964c609719bSwdenk		This delay is invoked four times per clock cycle so this
965c609719bSwdenk		controls the rate of data transfer.  The data rate thus
966c609719bSwdenk		is 1 / (I2C_DELAY * 4).
967c609719bSwdenk
96847cd00faSwdenk		CFG_I2C_INIT_BOARD
96947cd00faSwdenk
97047cd00faSwdenk                When a board is reset during an i2c bus transfer
97147cd00faSwdenk                chips might think that the current transfer is still
97247cd00faSwdenk                in progress. On some boards it is possible to access
97347cd00faSwdenk                the i2c SCLK line directly, either by using the
97447cd00faSwdenk                processor pin as a GPIO or by having a second pin
97547cd00faSwdenk                connected to the bus. If this option is defined a
97647cd00faSwdenk                custom i2c_init_board() routine in boards/xxx/board.c
97747cd00faSwdenk                is run early in the boot sequence.
97847cd00faSwdenk
979c609719bSwdenk- SPI Support:	CONFIG_SPI
980c609719bSwdenk
981c609719bSwdenk		Enables SPI driver (so far only tested with
982c609719bSwdenk		SPI EEPROM, also an instance works with Crystal A/D and
983c609719bSwdenk		D/As on the SACSng board)
984c609719bSwdenk
985c609719bSwdenk		CONFIG_SPI_X
986c609719bSwdenk
987c609719bSwdenk		Enables extended (16-bit) SPI EEPROM addressing.
988c609719bSwdenk		(symmetrical to CONFIG_I2C_X)
989c609719bSwdenk
990c609719bSwdenk		CONFIG_SOFT_SPI
991c609719bSwdenk
992c609719bSwdenk		Enables a software (bit-bang) SPI driver rather than
993c609719bSwdenk		using hardware support. This is a general purpose
994c609719bSwdenk		driver that only requires three general I/O port pins
995c609719bSwdenk		(two outputs, one input) to function. If this is
996c609719bSwdenk		defined, the board configuration must define several
997c609719bSwdenk		SPI configuration items (port pins to use, etc). For
998c609719bSwdenk		an example, see include/configs/sacsng.h.
999c609719bSwdenk
1000c609719bSwdenk- FPGA Support: CONFIG_FPGA_COUNT
1001c609719bSwdenk
1002c609719bSwdenk		Specify the number of FPGA devices to support.
1003c609719bSwdenk
1004c609719bSwdenk		CONFIG_FPGA
1005c609719bSwdenk
1006c609719bSwdenk		Used to specify the types of FPGA devices. For
1007c609719bSwdenk		example,
1008c609719bSwdenk 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
1009c609719bSwdenk
1010c609719bSwdenk 		CFG_FPGA_PROG_FEEDBACK
1011c609719bSwdenk
1012c609719bSwdenk		Enable printing of hash marks during FPGA
1013c609719bSwdenk		configuration.
1014c609719bSwdenk
1015c609719bSwdenk		CFG_FPGA_CHECK_BUSY
1016c609719bSwdenk
1017c609719bSwdenk		Enable checks on FPGA configuration interface busy
1018c609719bSwdenk		status by the configuration function. This option
1019c609719bSwdenk		will require a board or device specific function to
1020c609719bSwdenk		be written.
1021c609719bSwdenk
1022c609719bSwdenk		CONFIG_FPGA_DELAY
1023c609719bSwdenk
1024c609719bSwdenk		If defined, a function that provides delays in the
1025c609719bSwdenk		FPGA configuration driver.
1026c609719bSwdenk
1027c609719bSwdenk		CFG_FPGA_CHECK_CTRLC
1028c609719bSwdenk
1029c609719bSwdenk		Allow Control-C to interrupt FPGA configuration
1030c609719bSwdenk
1031c609719bSwdenk		CFG_FPGA_CHECK_ERROR
1032c609719bSwdenk
1033c609719bSwdenk		Check for configuration errors during FPGA bitfile
1034c609719bSwdenk		loading. For example, abort during Virtex II
1035c609719bSwdenk		configuration if the INIT_B line goes low (which
1036c609719bSwdenk		indicated a CRC error).
1037c609719bSwdenk
1038c609719bSwdenk		CFG_FPGA_WAIT_INIT
1039c609719bSwdenk
1040c609719bSwdenk		Maximum time to wait for the INIT_B line to deassert
1041c609719bSwdenk		after PROB_B has been deasserted during a Virtex II
1042c609719bSwdenk		FPGA configuration sequence. The default time is 500 mS.
1043c609719bSwdenk
1044c609719bSwdenk		CFG_FPGA_WAIT_BUSY
1045c609719bSwdenk
1046c609719bSwdenk		Maximum time to wait for BUSY to deassert during
1047c609719bSwdenk		Virtex II FPGA configuration. The default is 5 mS.
1048c609719bSwdenk
1049c609719bSwdenk		CFG_FPGA_WAIT_CONFIG
1050c609719bSwdenk
1051c609719bSwdenk		Time to wait after FPGA configuration. The default is
1052c609719bSwdenk		200 mS.
1053c609719bSwdenk
1054c609719bSwdenk- FPGA Support:	CONFIG_FPGA_COUNT
1055c609719bSwdenk
1056c609719bSwdenk 		Specify the number of FPGA devices to support.
1057c609719bSwdenk
1058c609719bSwdenk 		CONFIG_FPGA
1059c609719bSwdenk
1060c609719bSwdenk 		Used to specify the types of FPGA devices.  For example,
1061c609719bSwdenk 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
1062c609719bSwdenk
1063c609719bSwdenk 		CFG_FPGA_PROG_FEEDBACK
1064c609719bSwdenk
1065c609719bSwdenk 		Enable printing of hash marks during FPGA configuration.
1066c609719bSwdenk
1067c609719bSwdenk		CFG_FPGA_CHECK_BUSY
1068c609719bSwdenk
1069c609719bSwdenk		Enable checks on FPGA configuration interface busy
1070c609719bSwdenk		status by the configuration function. This option
1071c609719bSwdenk		will require a board or device specific function to
1072c609719bSwdenk		be written.
1073c609719bSwdenk
1074c609719bSwdenk		CONFIG_FPGA_DELAY
1075c609719bSwdenk
1076c609719bSwdenk		If defined, a function that provides delays in the FPGA
1077c609719bSwdenk		configuration driver.
1078c609719bSwdenk
1079c609719bSwdenk		CFG_FPGA_CHECK_CTRLC
1080c609719bSwdenk		Allow Control-C to interrupt FPGA configuration
1081c609719bSwdenk
1082c609719bSwdenk		CFG_FPGA_CHECK_ERROR
1083c609719bSwdenk
1084c609719bSwdenk		Check for configuration errors during FPGA bitfile
1085c609719bSwdenk		loading. For example, abort during Virtex II
1086c609719bSwdenk		configuration if the INIT_B line goes low (which
1087c609719bSwdenk		indicated a CRC error).
1088c609719bSwdenk
1089c609719bSwdenk		CFG_FPGA_WAIT_INIT
1090c609719bSwdenk
1091c609719bSwdenk		Maximum time to wait for the INIT_B line to deassert
1092c609719bSwdenk		after PROB_B has been deasserted during a Virtex II
1093c609719bSwdenk		FPGA configuration sequence. The default time is 500
1094c609719bSwdenk		mS.
1095c609719bSwdenk
1096c609719bSwdenk		CFG_FPGA_WAIT_BUSY
1097c609719bSwdenk
1098c609719bSwdenk		Maximum time to wait for BUSY to deassert during
1099c609719bSwdenk		Virtex II FPGA configuration. The default is 5 mS.
1100c609719bSwdenk
1101c609719bSwdenk		CFG_FPGA_WAIT_CONFIG
1102c609719bSwdenk
1103c609719bSwdenk		Time to wait after FPGA configuration. The default is
1104c609719bSwdenk		200 mS.
1105c609719bSwdenk
1106c609719bSwdenk- Configuration Management:
1107c609719bSwdenk		CONFIG_IDENT_STRING
1108c609719bSwdenk
1109c609719bSwdenk		If defined, this string will be added to the U-Boot
1110c609719bSwdenk		version information (U_BOOT_VERSION)
1111c609719bSwdenk
1112c609719bSwdenk- Vendor Parameter Protection:
1113c609719bSwdenk
1114c609719bSwdenk		U-Boot considers the values of the environment
1115c609719bSwdenk		variables "serial#" (Board Serial Number) and
1116c609719bSwdenk		"ethaddr" (Ethernet Address) to bb parameters that
1117c609719bSwdenk		are set once by the board vendor / manufacturer, and
1118c609719bSwdenk		protects these variables from casual modification by
1119c609719bSwdenk		the user. Once set, these variables are read-only,
1120c609719bSwdenk		and write or delete attempts are rejected. You can
1121c609719bSwdenk		change this behviour:
1122c609719bSwdenk
1123c609719bSwdenk		If CONFIG_ENV_OVERWRITE is #defined in your config
1124c609719bSwdenk		file, the write protection for vendor parameters is
112547cd00faSwdenk		completely disabled. Anybody can change or delete
1126c609719bSwdenk		these parameters.
1127c609719bSwdenk
1128c609719bSwdenk		Alternatively, if you #define _both_ CONFIG_ETHADDR
1129c609719bSwdenk		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1130c609719bSwdenk		ethernet address is installed in the environment,
1131c609719bSwdenk		which can be changed exactly ONCE by the user. [The
1132c609719bSwdenk		serial# is unaffected by this, i. e. it remains
1133c609719bSwdenk		read-only.]
1134c609719bSwdenk
1135c609719bSwdenk- Protected RAM:
1136c609719bSwdenk		CONFIG_PRAM
1137c609719bSwdenk
1138c609719bSwdenk		Define this variable to enable the reservation of
1139c609719bSwdenk		"protected RAM", i. e. RAM which is not overwritten
1140c609719bSwdenk		by U-Boot. Define CONFIG_PRAM to hold the number of
1141c609719bSwdenk		kB you want to reserve for pRAM. You can overwrite
1142c609719bSwdenk		this default value by defining an environment
1143c609719bSwdenk		variable "pram" to the number of kB you want to
1144c609719bSwdenk		reserve. Note that the board info structure will
1145c609719bSwdenk		still show the full amount of RAM. If pRAM is
1146c609719bSwdenk		reserved, a new environment variable "mem" will
1147c609719bSwdenk		automatically be defined to hold the amount of
1148c609719bSwdenk		remaining RAM in a form that can be passed as boot
1149c609719bSwdenk		argument to Linux, for instance like that:
1150c609719bSwdenk
1151c609719bSwdenk			setenv bootargs ... mem=\$(mem)
1152c609719bSwdenk			saveenv
1153c609719bSwdenk
1154c609719bSwdenk		This way you can tell Linux not to use this memory,
1155c609719bSwdenk		either, which results in a memory region that will
1156c609719bSwdenk		not be affected by reboots.
1157c609719bSwdenk
1158c609719bSwdenk		*WARNING* If your board configuration uses automatic
1159c609719bSwdenk		detection of the RAM size, you must make sure that
1160c609719bSwdenk		this memory test is non-destructive. So far, the
1161c609719bSwdenk		following board configurations are known to be
1162c609719bSwdenk		"pRAM-clean":
1163c609719bSwdenk
1164c609719bSwdenk			ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1165c609719bSwdenk			HERMES, IP860, RPXlite, LWMON, LANTEC,
1166c609719bSwdenk			PCU_E, FLAGADM, TQM8260
1167c609719bSwdenk
1168c609719bSwdenk- Error Recovery:
1169c609719bSwdenk		CONFIG_PANIC_HANG
1170c609719bSwdenk
1171c609719bSwdenk		Define this variable to stop the system in case of a
1172c609719bSwdenk		fatal error, so that you have to reset it manually.
1173c609719bSwdenk		This is probably NOT a good idea for an embedded
1174c609719bSwdenk		system where you want to system to reboot
1175c609719bSwdenk		automatically as fast as possible, but it may be
1176c609719bSwdenk		useful during development since you can try to debug
1177c609719bSwdenk		the conditions that lead to the situation.
1178c609719bSwdenk
1179c609719bSwdenk		CONFIG_NET_RETRY_COUNT
1180c609719bSwdenk
1181c609719bSwdenk		This variable defines the number of retries for
1182c609719bSwdenk		network operations like ARP, RARP, TFTP, or BOOTP
1183c609719bSwdenk		before giving up the operation. If not defined, a
1184c609719bSwdenk		default value of 5 is used.
1185c609719bSwdenk
1186c609719bSwdenk- Command Interpreter:
1187c609719bSwdenk		CFG_HUSH_PARSER
1188c609719bSwdenk
1189c609719bSwdenk		Define this variable to enable the "hush" shell (from
1190c609719bSwdenk		Busybox) as command line interpreter, thus enabling
1191c609719bSwdenk		powerful command line syntax like
1192c609719bSwdenk		if...then...else...fi conditionals or `&&' and '||'
1193c609719bSwdenk		constructs ("shell scripts").
1194c609719bSwdenk
1195c609719bSwdenk		If undefined, you get the old, much simpler behaviour
1196c609719bSwdenk		with a somewhat smaller memory footprint.
1197c609719bSwdenk
1198c609719bSwdenk
1199c609719bSwdenk		CFG_PROMPT_HUSH_PS2
1200c609719bSwdenk
1201c609719bSwdenk		This defines the secondary prompt string, which is
1202c609719bSwdenk		printed when the command interpreter needs more input
1203c609719bSwdenk		to complete a command. Usually "> ".
1204c609719bSwdenk
1205c609719bSwdenk	Note:
1206c609719bSwdenk
1207c609719bSwdenk                In the current implementation, the local variables
1208c609719bSwdenk                space and global environment variables space are
1209c609719bSwdenk                separated. Local variables are those you define by
12103b57fe0aSwdenk                simply typing `name=value'. To access a local
1211c609719bSwdenk                variable later on, you have write `$name' or
12123b57fe0aSwdenk                `${name}'; to execute the contents of a variable
12133b57fe0aSwdenk                directly type `$name' at the command prompt.
1214c609719bSwdenk
1215c609719bSwdenk		Global environment variables are those you use
1216c609719bSwdenk		setenv/printenv to work with. To run a command stored
1217c609719bSwdenk		in such a variable, you need to use the run command,
1218c609719bSwdenk		and you must not use the '$' sign to access them.
1219c609719bSwdenk
1220c609719bSwdenk		To store commands and special characters in a
1221c609719bSwdenk		variable, please use double quotation marks
1222c609719bSwdenk		surrounding the whole text of the variable, instead
1223c609719bSwdenk		of the backslashes before semicolons and special
1224c609719bSwdenk		symbols.
1225c609719bSwdenk
1226c609719bSwdenk- Default Environment
1227c609719bSwdenk		CONFIG_EXTRA_ENV_SETTINGS
1228c609719bSwdenk
1229c609719bSwdenk		Define this to contain any number of null terminated
1230c609719bSwdenk		strings (variable = value pairs) that will be part of
1231c609719bSwdenk		the default enviroment compiled into the boot image.
12322262cfeeSwdenk
1233c609719bSwdenk		For example, place something like this in your
1234c609719bSwdenk		board's config file:
1235c609719bSwdenk
1236c609719bSwdenk		#define CONFIG_EXTRA_ENV_SETTINGS \
1237c609719bSwdenk			"myvar1=value1\0" \
1238c609719bSwdenk			"myvar2=value2\0"
1239c609719bSwdenk
1240c609719bSwdenk		Warning: This method is based on knowledge about the
1241c609719bSwdenk		internal format how the environment is stored by the
12422262cfeeSwdenk		U-Boot code. This is NOT an official, exported
1243c609719bSwdenk		interface! Although it is unlikely that this format
12442262cfeeSwdenk		will change soon, but there is no guarantee either.
1245c609719bSwdenk		You better know what you are doing here.
1246c609719bSwdenk
1247c609719bSwdenk		Note: overly (ab)use of the default environment is
1248c609719bSwdenk		discouraged. Make sure to check other ways to preset
1249c609719bSwdenk		the environment like the autoscript function or the
1250c609719bSwdenk		boot command first.
1251c609719bSwdenk
12522abbe075Swdenk- DataFlash Support
12532abbe075Swdenk		CONFIG_HAS_DATAFLASH
12542abbe075Swdenk
12552abbe075Swdenk                Defining this option enables DataFlash features and
12562abbe075Swdenk                allows to read/write in Dataflash via the standard
12572abbe075Swdenk                commands cp, md...
12582abbe075Swdenk
1259c609719bSwdenk- Show boot progress
1260c609719bSwdenk		CONFIG_SHOW_BOOT_PROGRESS
1261c609719bSwdenk
1262c609719bSwdenk		Defining this option allows to add some board-
1263c609719bSwdenk		specific code (calling a user-provided function
1264c609719bSwdenk		"show_boot_progress(int)") that enables you to show
1265c609719bSwdenk		the system's boot progress on some display (for
1266c609719bSwdenk		example, some LED's) on your board. At the moment,
1267c609719bSwdenk		the following checkpoints are implemented:
1268c609719bSwdenk
1269c609719bSwdenk  Arg	Where			When
1270c609719bSwdenk    1	common/cmd_bootm.c	before attempting to boot an image
1271c609719bSwdenk   -1	common/cmd_bootm.c	Image header has bad     magic number
1272c609719bSwdenk    2	common/cmd_bootm.c	Image header has correct magic number
1273c609719bSwdenk   -2	common/cmd_bootm.c	Image header has bad     checksum
1274c609719bSwdenk    3	common/cmd_bootm.c	Image header has correct checksum
1275c609719bSwdenk   -3	common/cmd_bootm.c	Image data   has bad     checksum
1276c609719bSwdenk    4	common/cmd_bootm.c	Image data   has correct checksum
1277c609719bSwdenk   -4	common/cmd_bootm.c	Image is for unsupported architecture
1278c609719bSwdenk    5	common/cmd_bootm.c	Architecture check OK
1279c609719bSwdenk   -5	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1280c609719bSwdenk    6	common/cmd_bootm.c	Image Type check OK
1281c609719bSwdenk   -6	common/cmd_bootm.c	gunzip uncompression error
1282c609719bSwdenk   -7	common/cmd_bootm.c	Unimplemented compression type
1283c609719bSwdenk    7	common/cmd_bootm.c	Uncompression OK
1284c609719bSwdenk   -8	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1285c609719bSwdenk    8	common/cmd_bootm.c	Image Type check OK
1286c609719bSwdenk   -9	common/cmd_bootm.c	Unsupported OS (not Linux, BSD, VxWorks, QNX)
1287c609719bSwdenk    9	common/cmd_bootm.c	Start initial ramdisk verification
1288c609719bSwdenk  -10	common/cmd_bootm.c	Ramdisk header has bad     magic number
1289c609719bSwdenk  -11	common/cmd_bootm.c	Ramdisk header has bad     checksum
1290c609719bSwdenk   10	common/cmd_bootm.c	Ramdisk header is OK
1291c609719bSwdenk  -12	common/cmd_bootm.c	Ramdisk data   has bad     checksum
1292c609719bSwdenk   11	common/cmd_bootm.c	Ramdisk data   has correct checksum
1293c609719bSwdenk   12	common/cmd_bootm.c	Ramdisk verification complete, start loading
1294c609719bSwdenk  -13	common/cmd_bootm.c	Wrong Image Type (not PPC Linux Ramdisk)
1295c609719bSwdenk   13	common/cmd_bootm.c	Start multifile image verification
1296c609719bSwdenk   14	common/cmd_bootm.c	No initial ramdisk, no multifile, continue.
1297c609719bSwdenk   15	common/cmd_bootm.c	All preparation done, transferring control to OS
1298c609719bSwdenk
1299c609719bSwdenk   -1	common/cmd_doc.c	Bad usage of "doc" command
1300c609719bSwdenk   -1	common/cmd_doc.c	No boot device
1301c609719bSwdenk   -1	common/cmd_doc.c	Unknown Chip ID on boot device
1302c609719bSwdenk   -1	common/cmd_doc.c	Read Error on boot device
1303c609719bSwdenk   -1	common/cmd_doc.c	Image header has bad magic number
1304c609719bSwdenk
1305c609719bSwdenk   -1	common/cmd_ide.c	Bad usage of "ide" command
1306c609719bSwdenk   -1	common/cmd_ide.c	No boot device
1307c609719bSwdenk   -1	common/cmd_ide.c	Unknown boot device
1308c609719bSwdenk   -1	common/cmd_ide.c	Unknown partition table
1309c609719bSwdenk   -1	common/cmd_ide.c	Invalid partition type
1310c609719bSwdenk   -1	common/cmd_ide.c	Read Error on boot device
1311c609719bSwdenk   -1	common/cmd_ide.c	Image header has bad magic number
1312c609719bSwdenk
1313c609719bSwdenk   -1	common/cmd_nvedit.c	Environment not changable, but has bad CRC
1314c609719bSwdenk
1315c609719bSwdenk
1316c609719bSwdenkModem Support:
1317c609719bSwdenk--------------
1318c609719bSwdenk
131985ec0bccSwdenk[so far only for SMDK2400 and TRAB boards]
1320c609719bSwdenk
1321c609719bSwdenk- Modem support endable:
1322c609719bSwdenk		CONFIG_MODEM_SUPPORT
1323c609719bSwdenk
1324c609719bSwdenk- RTS/CTS Flow control enable:
1325c609719bSwdenk		CONFIG_HWFLOW
1326c609719bSwdenk
1327c609719bSwdenk- Modem debug support:
1328c609719bSwdenk		CONFIG_MODEM_SUPPORT_DEBUG
1329c609719bSwdenk
1330c609719bSwdenk		Enables debugging stuff (char screen[1024], dbg())
1331c609719bSwdenk		for modem support. Useful only with BDI2000.
1332c609719bSwdenk
1333c609719bSwdenk- General:
1334c609719bSwdenk
1335c609719bSwdenk		In the target system modem support is enabled when a
1336c609719bSwdenk		specific key (key combination) is pressed during
1337c609719bSwdenk		power-on. Otherwise U-Boot will boot normally
1338c609719bSwdenk		(autoboot). The key_pressed() fuction is called from
1339c609719bSwdenk		board_init(). Currently key_pressed() is a dummy
1340c609719bSwdenk		function, returning 1 and thus enabling modem
1341c609719bSwdenk		initialization.
1342c609719bSwdenk
1343c609719bSwdenk		If there are no modem init strings in the
1344c609719bSwdenk		environment, U-Boot proceed to autoboot; the
1345c609719bSwdenk		previous output (banner, info printfs) will be
1346c609719bSwdenk		supressed, though.
1347c609719bSwdenk
1348c609719bSwdenk		See also: doc/README.Modem
1349c609719bSwdenk
1350c609719bSwdenk
1351c609719bSwdenk
1352c609719bSwdenk
1353c609719bSwdenkConfiguration Settings:
1354c609719bSwdenk-----------------------
1355c609719bSwdenk
1356c609719bSwdenk- CFG_LONGHELP: Defined when you want long help messages included;
1357c609719bSwdenk		undefine this when you're short of memory.
1358c609719bSwdenk
1359c609719bSwdenk- CFG_PROMPT:	This is what U-Boot prints on the console to
1360c609719bSwdenk		prompt for user input.
1361c609719bSwdenk
1362c609719bSwdenk- CFG_CBSIZE:	Buffer size for input from the Console
1363c609719bSwdenk
1364c609719bSwdenk- CFG_PBSIZE:	Buffer size for Console output
1365c609719bSwdenk
1366c609719bSwdenk- CFG_MAXARGS:	max. Number of arguments accepted for monitor commands
1367c609719bSwdenk
1368c609719bSwdenk- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1369c609719bSwdenk		the application (usually a Linux kernel) when it is
1370c609719bSwdenk		booted
1371c609719bSwdenk
1372c609719bSwdenk- CFG_BAUDRATE_TABLE:
1373c609719bSwdenk		List of legal baudrate settings for this board.
1374c609719bSwdenk
1375c609719bSwdenk- CFG_CONSOLE_INFO_QUIET
1376c609719bSwdenk 		Suppress display of console information at boot.
1377c609719bSwdenk
1378c609719bSwdenk- CFG_CONSOLE_IS_IN_ENV
1379c609719bSwdenk 		If the board specific function
1380c609719bSwdenk 			extern int overwrite_console (void);
1381c609719bSwdenk 		returns 1, the stdin, stderr and stdout are switched to the
1382c609719bSwdenk		serial port, else the settings in the environment are used.
1383c609719bSwdenk
1384c609719bSwdenk- CFG_CONSOLE_OVERWRITE_ROUTINE
1385c609719bSwdenk 		Enable the call to overwrite_console().
1386c609719bSwdenk
1387c609719bSwdenk- CFG_CONSOLE_ENV_OVERWRITE
1388c609719bSwdenk		Enable overwrite of previous console environment settings.
1389c609719bSwdenk
1390c609719bSwdenk- CFG_MEMTEST_START, CFG_MEMTEST_END:
1391c609719bSwdenk		Begin and End addresses of the area used by the
1392c609719bSwdenk		simple memory test.
1393c609719bSwdenk
1394c609719bSwdenk- CFG_ALT_MEMTEST:
1395c609719bSwdenk 		Enable an alternate, more extensive memory test.
1396c609719bSwdenk
1397c609719bSwdenk- CFG_TFTP_LOADADDR:
1398c609719bSwdenk		Default load address for network file downloads
1399c609719bSwdenk
1400c609719bSwdenk- CFG_LOADS_BAUD_CHANGE:
1401c609719bSwdenk		Enable temporary baudrate change while serial download
1402c609719bSwdenk
1403c609719bSwdenk- CFG_SDRAM_BASE:
1404c609719bSwdenk		Physical start address of SDRAM. _Must_ be 0 here.
1405c609719bSwdenk
1406c609719bSwdenk- CFG_MBIO_BASE:
1407c609719bSwdenk		Physical start address of Motherboard I/O (if using a
1408c609719bSwdenk		Cogent motherboard)
1409c609719bSwdenk
1410c609719bSwdenk- CFG_FLASH_BASE:
1411c609719bSwdenk		Physical start address of Flash memory.
1412c609719bSwdenk
1413c609719bSwdenk- CFG_MONITOR_BASE:
1414c609719bSwdenk		Physical start address of boot monitor code (set by
1415c609719bSwdenk		make config files to be same as the text base address
1416c609719bSwdenk		(TEXT_BASE) used when linking) - same as
1417c609719bSwdenk		CFG_FLASH_BASE when booting from flash.
1418c609719bSwdenk
1419c609719bSwdenk- CFG_MONITOR_LEN:
14203b57fe0aSwdenk                Size of memory reserved for monitor code, used to
14213b57fe0aSwdenk                determine _at_compile_time_ (!) if the environment is
14223b57fe0aSwdenk                embedded within the U-Boot image, or in a separate
14233b57fe0aSwdenk                flash sector.
1424c609719bSwdenk
1425c609719bSwdenk- CFG_MALLOC_LEN:
1426c609719bSwdenk		Size of DRAM reserved for malloc() use.
1427c609719bSwdenk
1428c609719bSwdenk- CFG_BOOTMAPSZ:
1429c609719bSwdenk		Maximum size of memory mapped by the startup code of
1430c609719bSwdenk		the Linux kernel; all data that must be processed by
1431c609719bSwdenk		the Linux kernel (bd_info, boot arguments, eventually
1432c609719bSwdenk		initrd image) must be put below this limit.
1433c609719bSwdenk
1434c609719bSwdenk- CFG_MAX_FLASH_BANKS:
1435c609719bSwdenk		Max number of Flash memory banks
1436c609719bSwdenk
1437c609719bSwdenk- CFG_MAX_FLASH_SECT:
1438c609719bSwdenk		Max number of sectors on a Flash chip
1439c609719bSwdenk
1440c609719bSwdenk- CFG_FLASH_ERASE_TOUT:
1441c609719bSwdenk		Timeout for Flash erase operations (in ms)
1442c609719bSwdenk
1443c609719bSwdenk- CFG_FLASH_WRITE_TOUT:
1444c609719bSwdenk		Timeout for Flash write operations (in ms)
1445c609719bSwdenk
1446c609719bSwdenk- CFG_DIRECT_FLASH_TFTP:
1447c609719bSwdenk
1448c609719bSwdenk		Enable TFTP transfers directly to flash memory;
1449c609719bSwdenk		without this option such a download has to be
1450c609719bSwdenk		performed in two steps: (1) download to RAM, and (2)
1451c609719bSwdenk		copy from RAM to flash.
1452c609719bSwdenk
1453c609719bSwdenk		The two-step approach is usually more reliable, since
1454c609719bSwdenk		you can check if the download worked before you erase
1455c609719bSwdenk		the flash, but in some situations (when sytem RAM is
1456c609719bSwdenk		too limited to allow for a tempory copy of the
1457c609719bSwdenk		downloaded image) this option may be very useful.
1458c609719bSwdenk
1459c609719bSwdenk- CFG_FLASH_CFI:
1460c609719bSwdenk		Define if the flash driver uses extra elements in the
1461c609719bSwdenk		common flash structure for storing flash geometry
146253cf9435Sstroese
146353cf9435Sstroese- CFG_RX_ETH_BUFFER:
146453cf9435Sstroese		Defines the number of ethernet receive buffers. On some
146553cf9435Sstroese		ethernet controllers it is recommended to set this value
146653cf9435Sstroese		to 8 or even higher (EEPRO100 or 405 EMAC), since all
146753cf9435Sstroese		buffers can be full shortly after enabling the interface
146853cf9435Sstroese		on high ethernet traffic.
146953cf9435Sstroese		Defaults to 4 if not defined.
1470c609719bSwdenk
1471c609719bSwdenkThe following definitions that deal with the placement and management
1472c609719bSwdenkof environment data (variable area); in general, we support the
1473c609719bSwdenkfollowing configurations:
1474c609719bSwdenk
1475c609719bSwdenk- CFG_ENV_IS_IN_FLASH:
1476c609719bSwdenk
1477c609719bSwdenk	Define this if the environment is in flash memory.
1478c609719bSwdenk
1479c609719bSwdenk	a) The environment occupies one whole flash sector, which is
1480c609719bSwdenk	   "embedded" in the text segment with the U-Boot code. This
1481c609719bSwdenk	   happens usually with "bottom boot sector" or "top boot
1482c609719bSwdenk	   sector" type flash chips, which have several smaller
1483c609719bSwdenk	   sectors at the start or the end. For instance, such a
1484c609719bSwdenk	   layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1485c609719bSwdenk	   such a case you would place the environment in one of the
1486c609719bSwdenk	   4 kB sectors - with U-Boot code before and after it. With
1487c609719bSwdenk	   "top boot sector" type flash chips, you would put the
1488c609719bSwdenk	   environment in one of the last sectors, leaving a gap
1489c609719bSwdenk	   between U-Boot and the environment.
1490c609719bSwdenk
1491c609719bSwdenk	- CFG_ENV_OFFSET:
1492c609719bSwdenk
1493c609719bSwdenk	   Offset of environment data (variable area) to the
1494c609719bSwdenk	   beginning of flash memory; for instance, with bottom boot
1495c609719bSwdenk	   type flash chips the second sector can be used: the offset
1496c609719bSwdenk	   for this sector is given here.
1497c609719bSwdenk
1498c609719bSwdenk	   CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1499c609719bSwdenk
1500c609719bSwdenk	- CFG_ENV_ADDR:
1501c609719bSwdenk
1502c609719bSwdenk	   This is just another way to specify the start address of
1503c609719bSwdenk	   the flash sector containing the environment (instead of
1504c609719bSwdenk	   CFG_ENV_OFFSET).
1505c609719bSwdenk
1506c609719bSwdenk	- CFG_ENV_SECT_SIZE:
1507c609719bSwdenk
1508c609719bSwdenk	   Size of the sector containing the environment.
1509c609719bSwdenk
1510c609719bSwdenk
1511c609719bSwdenk	b) Sometimes flash chips have few, equal sized, BIG sectors.
1512c609719bSwdenk	   In such a case you don't want to spend a whole sector for
1513c609719bSwdenk	   the environment.
1514c609719bSwdenk
1515c609719bSwdenk	- CFG_ENV_SIZE:
1516c609719bSwdenk
1517c609719bSwdenk	   If you use this in combination with CFG_ENV_IS_IN_FLASH
1518c609719bSwdenk	   and CFG_ENV_SECT_SIZE, you can specify to use only a part
1519c609719bSwdenk	   of this flash sector for the environment. This saves
1520c609719bSwdenk	   memory for the RAM copy of the environment.
1521c609719bSwdenk
1522c609719bSwdenk	   It may also save flash memory if you decide to use this
1523c609719bSwdenk	   when your environment is "embedded" within U-Boot code,
1524c609719bSwdenk	   since then the remainder of the flash sector could be used
1525c609719bSwdenk	   for U-Boot code. It should be pointed out that this is
1526c609719bSwdenk	   STRONGLY DISCOURAGED from a robustness point of view:
1527c609719bSwdenk	   updating the environment in flash makes it always
1528c609719bSwdenk	   necessary to erase the WHOLE sector. If something goes
1529c609719bSwdenk	   wrong before the contents has been restored from a copy in
1530c609719bSwdenk	   RAM, your target system will be dead.
1531c609719bSwdenk
1532c609719bSwdenk	- CFG_ENV_ADDR_REDUND
1533c609719bSwdenk	  CFG_ENV_SIZE_REDUND
1534c609719bSwdenk
1535c609719bSwdenk	   These settings describe a second storage area used to hold
1536c609719bSwdenk	   a redundand copy of the environment data, so that there is
15373e38691eSwdenk	   a valid backup copy in case there is a power failure during
1538c609719bSwdenk	   a "saveenv" operation.
1539c609719bSwdenk
1540c609719bSwdenkBE CAREFUL! Any changes to the flash layout, and some changes to the
1541c609719bSwdenksource code will make it necessary to adapt <board>/u-boot.lds*
1542c609719bSwdenkaccordingly!
1543c609719bSwdenk
1544c609719bSwdenk
1545c609719bSwdenk- CFG_ENV_IS_IN_NVRAM:
1546c609719bSwdenk
1547c609719bSwdenk	Define this if you have some non-volatile memory device
1548c609719bSwdenk	(NVRAM, battery buffered SRAM) which you want to use for the
1549c609719bSwdenk	environment.
1550c609719bSwdenk
1551c609719bSwdenk	- CFG_ENV_ADDR:
1552c609719bSwdenk	- CFG_ENV_SIZE:
1553c609719bSwdenk
1554c609719bSwdenk	  These two #defines are used to determin the memory area you
1555c609719bSwdenk	  want to use for environment. It is assumed that this memory
1556c609719bSwdenk	  can just be read and written to, without any special
1557c609719bSwdenk	  provision.
1558c609719bSwdenk
1559c609719bSwdenkBE CAREFUL! The first access to the environment happens quite early
1560c609719bSwdenkin U-Boot initalization (when we try to get the setting of for the
1561c609719bSwdenkconsole baudrate). You *MUST* have mappend your NVRAM area then, or
1562c609719bSwdenkU-Boot will hang.
1563c609719bSwdenk
1564c609719bSwdenkPlease note that even with NVRAM we still use a copy of the
1565c609719bSwdenkenvironment in RAM: we could work on NVRAM directly, but we want to
1566c609719bSwdenkkeep settings there always unmodified except somebody uses "saveenv"
1567c609719bSwdenkto save the current settings.
1568c609719bSwdenk
1569c609719bSwdenk
1570c609719bSwdenk- CFG_ENV_IS_IN_EEPROM:
1571c609719bSwdenk
1572c609719bSwdenk	Use this if you have an EEPROM or similar serial access
1573c609719bSwdenk	device and a driver for it.
1574c609719bSwdenk
1575c609719bSwdenk	- CFG_ENV_OFFSET:
1576c609719bSwdenk	- CFG_ENV_SIZE:
1577c609719bSwdenk
1578c609719bSwdenk	  These two #defines specify the offset and size of the
1579c609719bSwdenk	  environment area within the total memory of your EEPROM.
1580c609719bSwdenk
1581c609719bSwdenk	- CFG_I2C_EEPROM_ADDR:
1582c609719bSwdenk	  If defined, specified the chip address of the EEPROM device.
1583c609719bSwdenk	  The default address is zero.
1584c609719bSwdenk
1585c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_BITS:
1586c609719bSwdenk	  If defined, the number of bits used to address bytes in a
1587c609719bSwdenk	  single page in the EEPROM device.  A 64 byte page, for example
1588c609719bSwdenk	  would require six bits.
1589c609719bSwdenk
1590c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1591c609719bSwdenk	  If defined, the number of milliseconds to delay between
1592c609719bSwdenk	  page writes.  The default is zero milliseconds.
1593c609719bSwdenk
1594c609719bSwdenk	- CFG_I2C_EEPROM_ADDR_LEN:
1595c609719bSwdenk	  The length in bytes of the EEPROM memory array address.  Note
1596c609719bSwdenk	  that this is NOT the chip address length!
1597c609719bSwdenk
1598c609719bSwdenk	- CFG_EEPROM_SIZE:
1599c609719bSwdenk	  The size in bytes of the EEPROM device.
1600c609719bSwdenk
1601c609719bSwdenk
1602c609719bSwdenk- CFG_SPI_INIT_OFFSET
1603c609719bSwdenk
1604c609719bSwdenk	Defines offset to the initial SPI buffer area in DPRAM. The
1605c609719bSwdenk	area is used at an early stage (ROM part) if the environment
1606c609719bSwdenk	is configured to reside in the SPI EEPROM: We need a 520 byte
1607c609719bSwdenk	scratch DPRAM area. It is used between the two initialization
1608c609719bSwdenk	calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1609c609719bSwdenk	to be a good choice since it makes it far enough from the
1610c609719bSwdenk	start of the data area as well as from the stack pointer.
1611c609719bSwdenk
1612c609719bSwdenkPlease note that the environment is read-only as long as the monitor
1613c609719bSwdenkhas been relocated to RAM and a RAM copy of the environment has been
1614c609719bSwdenkcreated; also, when using EEPROM you will have to use getenv_r()
1615c609719bSwdenkuntil then to read environment variables.
1616c609719bSwdenk
161785ec0bccSwdenkThe environment is protected by a CRC32 checksum. Before the monitor
161885ec0bccSwdenkis relocated into RAM, as a result of a bad CRC you will be working
161985ec0bccSwdenkwith the compiled-in default environment - *silently*!!! [This is
162085ec0bccSwdenknecessary, because the first environment variable we need is the
162185ec0bccSwdenk"baudrate" setting for the console - if we have a bad CRC, we don't
162285ec0bccSwdenkhave any device yet where we could complain.]
1623c609719bSwdenk
1624c609719bSwdenkNote: once the monitor has been relocated, then it will complain if
1625c609719bSwdenkthe default environment is used; a new CRC is computed as soon as you
162685ec0bccSwdenkuse the "saveenv" command to store a valid environment.
1627c609719bSwdenk
1628c609719bSwdenk
1629c609719bSwdenkLow Level (hardware related) configuration options:
1630dc7c9a1aSwdenk---------------------------------------------------
1631c609719bSwdenk
1632c609719bSwdenk- CFG_CACHELINE_SIZE:
1633c609719bSwdenk		Cache Line Size of the CPU.
1634c609719bSwdenk
1635c609719bSwdenk- CFG_DEFAULT_IMMR:
1636c609719bSwdenk		Default address of the IMMR after system reset.
1637c609719bSwdenk		Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1638c609719bSwdenk		to be able to adjust the position of the IMMR
1639c609719bSwdenk		register after a reset.
1640c609719bSwdenk
16417f6c2cbcSwdenk- Floppy Disk Support:
16427f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER
16437f6c2cbcSwdenk
16447f6c2cbcSwdenk		the default drive number (default value 0)
16457f6c2cbcSwdenk
16467f6c2cbcSwdenk		CFG_ISA_IO_STRIDE
16477f6c2cbcSwdenk
16487f6c2cbcSwdenk		defines the spacing between fdc chipset registers
16497f6c2cbcSwdenk		(default value 1)
16507f6c2cbcSwdenk
16517f6c2cbcSwdenk		CFG_ISA_IO_OFFSET
16527f6c2cbcSwdenk
16537f6c2cbcSwdenk		defines the offset of register from address. It
16547f6c2cbcSwdenk		depends on which part of the data bus is connected to
16557f6c2cbcSwdenk		the fdc chipset. (default value 0)
16567f6c2cbcSwdenk
16577f6c2cbcSwdenk		If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
16587f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER are undefined, they take their
16597f6c2cbcSwdenk		default value.
16607f6c2cbcSwdenk
16617f6c2cbcSwdenk		if CFG_FDC_HW_INIT is defined, then the function
16627f6c2cbcSwdenk		fdc_hw_init() is called at the beginning of the FDC
16637f6c2cbcSwdenk		setup. fdc_hw_init() must be provided by the board
16647f6c2cbcSwdenk		source code. It is used to make hardware dependant
16657f6c2cbcSwdenk		initializations.
16667f6c2cbcSwdenk
1667c609719bSwdenk- CFG_IMMR:	Physical address of the Internal Memory Mapped
1668c609719bSwdenk		Register; DO NOT CHANGE! (11-4)
1669c609719bSwdenk		[MPC8xx systems only]
1670c609719bSwdenk
1671c609719bSwdenk- CFG_INIT_RAM_ADDR:
1672c609719bSwdenk
1673c609719bSwdenk		Start address of memory area tha can be used for
1674c609719bSwdenk		initial data and stack; please note that this must be
1675c609719bSwdenk		writable memory that is working WITHOUT special
1676c609719bSwdenk		initialization, i. e. you CANNOT use normal RAM which
1677c609719bSwdenk		will become available only after programming the
1678c609719bSwdenk		memory controller and running certain initialization
1679c609719bSwdenk		sequences.
1680c609719bSwdenk
1681c609719bSwdenk		U-Boot uses the following memory types:
1682c609719bSwdenk		- MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1683c609719bSwdenk		- MPC824X: data cache
1684c609719bSwdenk		- PPC4xx:  data cache
1685c609719bSwdenk
168685ec0bccSwdenk- CFG_GBL_DATA_OFFSET:
1687c609719bSwdenk
1688c609719bSwdenk		Offset of the initial data structure in the memory
1689c609719bSwdenk		area defined by CFG_INIT_RAM_ADDR. Usually
169085ec0bccSwdenk		CFG_GBL_DATA_OFFSET is chosen such that the initial
1691c609719bSwdenk		data is located at the end of the available space
1692c609719bSwdenk		(sometimes written as (CFG_INIT_RAM_END -
1693c609719bSwdenk		CFG_INIT_DATA_SIZE), and the initial stack is just
1694c609719bSwdenk		below that area (growing from (CFG_INIT_RAM_ADDR +
169585ec0bccSwdenk		CFG_GBL_DATA_OFFSET) downward.
1696c609719bSwdenk
1697c609719bSwdenk	Note:
1698c609719bSwdenk		On the MPC824X (or other systems that use the data
1699c609719bSwdenk		cache for initial memory) the address chosen for
1700c609719bSwdenk		CFG_INIT_RAM_ADDR is basically arbitrary - it must
1701c609719bSwdenk		point to an otherwise UNUSED address space between
1702c609719bSwdenk		the top of RAM and the start of the PCI space.
1703c609719bSwdenk
1704c609719bSwdenk- CFG_SIUMCR:	SIU Module Configuration (11-6)
1705c609719bSwdenk
1706c609719bSwdenk- CFG_SYPCR:	System Protection Control (11-9)
1707c609719bSwdenk
1708c609719bSwdenk- CFG_TBSCR:	Time Base Status and Control (11-26)
1709c609719bSwdenk
1710c609719bSwdenk- CFG_PISCR:	Periodic Interrupt Status and Control (11-31)
1711c609719bSwdenk
1712c609719bSwdenk- CFG_PLPRCR:	PLL, Low-Power, and Reset Control Register (15-30)
1713c609719bSwdenk
1714c609719bSwdenk- CFG_SCCR:	System Clock and reset Control Register (15-27)
1715c609719bSwdenk
1716c609719bSwdenk- CFG_OR_TIMING_SDRAM:
1717c609719bSwdenk		SDRAM timing
1718c609719bSwdenk
1719c609719bSwdenk- CFG_MAMR_PTA:
1720c609719bSwdenk		periodic timer for refresh
1721c609719bSwdenk
1722c609719bSwdenk- CFG_DER:	Debug Event Register (37-47)
1723c609719bSwdenk
1724c609719bSwdenk- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1725c609719bSwdenk  CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1726c609719bSwdenk  CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1727c609719bSwdenk  CFG_BR1_PRELIM:
1728c609719bSwdenk		Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1729c609719bSwdenk
1730c609719bSwdenk- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1731c609719bSwdenk  CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1732c609719bSwdenk  CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1733c609719bSwdenk		Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1734c609719bSwdenk
1735c609719bSwdenk- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1736c609719bSwdenk  CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1737c609719bSwdenk		Machine Mode Register and Memory Periodic Timer
1738c609719bSwdenk		Prescaler definitions (SDRAM timing)
1739c609719bSwdenk
1740c609719bSwdenk- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1741c609719bSwdenk		enable I2C microcode relocation patch (MPC8xx);
1742c609719bSwdenk		define relocation offset in DPRAM [DSP2]
1743c609719bSwdenk
1744c609719bSwdenk- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1745c609719bSwdenk		enable SPI microcode relocation patch (MPC8xx);
1746c609719bSwdenk		define relocation offset in DPRAM [SCC4]
1747c609719bSwdenk
1748c609719bSwdenk- CFG_USE_OSCCLK:
1749c609719bSwdenk		Use OSCM clock mode on MBX8xx board. Be careful,
1750c609719bSwdenk		wrong setting might damage your board. Read
1751c609719bSwdenk		doc/README.MBX before setting this variable!
1752c609719bSwdenk
1753ea909b76Swdenk- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1754ea909b76Swdenk		Offset of the bootmode word in DPRAM used by post
1755ea909b76Swdenk		(Power On Self Tests). This definition overrides
1756ea909b76Swdenk		#define'd default value in commproc.h resp.
1757ea909b76Swdenk		cpm_8260.h.
1758ea909b76Swdenk
17595d232d0eSwdenk- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
17605d232d0eSwdenk  CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
17615d232d0eSwdenk  CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
17625d232d0eSwdenk  CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
17635d232d0eSwdenk  CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
17645d232d0eSwdenk  CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
17655d232d0eSwdenk  CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
17665d232d0eSwdenk  CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
17675d232d0eSwdenk		Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
17685d232d0eSwdenk
1769c609719bSwdenkBuilding the Software:
1770c609719bSwdenk======================
1771c609719bSwdenk
1772c609719bSwdenkBuilding U-Boot has been tested in native PPC environments (on a
1773c609719bSwdenkPowerBook G3 running LinuxPPC 2000) and in cross environments
1774c609719bSwdenk(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1775c609719bSwdenkNetBSD 1.5 on x86).
1776c609719bSwdenk
1777c609719bSwdenkIf you are not using a native PPC environment, it is assumed that you
1778c609719bSwdenkhave the GNU cross compiling tools available in your path and named
1779c609719bSwdenkwith a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1780c609719bSwdenkyou are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1781c609719bSwdenkthe definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1782c609719bSwdenkchange it to:
1783c609719bSwdenk
1784c609719bSwdenk	CROSS_COMPILE = ppc_4xx-
1785c609719bSwdenk
1786c609719bSwdenk
1787c609719bSwdenkU-Boot is intended to be  simple  to  build.  After  installing  the
1788c609719bSwdenksources	 you must configure U-Boot for one specific board type. This
1789c609719bSwdenkis done by typing:
1790c609719bSwdenk
1791c609719bSwdenk	make NAME_config
1792c609719bSwdenk
1793c609719bSwdenkwhere "NAME_config" is the name of one of the existing
1794c609719bSwdenkconfigurations; the following names are supported:
1795c609719bSwdenk
1796c609719bSwdenk    ADCIOP_config	  GTH_config		TQM850L_config
1797c609719bSwdenk    ADS860_config	  IP860_config		TQM855L_config
1798c609719bSwdenk    AR405_config	  IVML24_config		TQM860L_config
1799c609719bSwdenk    CANBT_config	  IVMS8_config		WALNUT405_config
1800c609719bSwdenk    CPCI405_config	  LANTEC_config		cogent_common_config
1801c609719bSwdenk    CPCIISER4_config	  MBX_config		cogent_mpc8260_config
1802c609719bSwdenk    CU824_config	  MBX860T_config	cogent_mpc8xx_config
1803c609719bSwdenk    ESTEEM192E_config	  RPXlite_config	hermes_config
1804c609719bSwdenk    ETX094_config	  RPXsuper_config	hymod_config
1805c609719bSwdenk    FADS823_config	  SM850_config		lwmon_config
1806c609719bSwdenk    FADS850SAR_config	  SPD823TS_config	pcu_e_config
1807c609719bSwdenk    FADS860T_config	  SXNI855T_config	rsdproto_config
1808c609719bSwdenk    FPS850L_config	  Sandpoint8240_config	sbc8260_config
1809c609719bSwdenk    GENIETV_config	  TQM823L_config	PIP405_config
1810384ae025Swdenk    GEN860T_config	  EBONY_config		FPS860L_config
18117f70e853Swdenk    ELPT860_config	  cmi_mpc5xx_config	NETVIA_config
18122abbe075Swdenk    at91rm9200dk_config
1813c609719bSwdenk
1814c609719bSwdenkNote: for some board special configuration names may exist; check  if
1815c609719bSwdenk      additional  information is available from the board vendor; for
1816c609719bSwdenk      instance, the TQM8xxL systems run normally at 50 MHz and use  a
1817c609719bSwdenk      SCC  for	10baseT	 ethernet; there are also systems with 80 MHz
1818c609719bSwdenk      CPU clock, and an optional Fast Ethernet	module	is  available
1819c609719bSwdenk      for  CPU's  with FEC. You can select such additional "features"
1820c609719bSwdenk      when chosing the configuration, i. e.
1821c609719bSwdenk
1822c609719bSwdenk      make TQM860L_config
1823c609719bSwdenk	- will configure for a plain TQM860L, i. e. 50MHz, no FEC
1824c609719bSwdenk
1825c609719bSwdenk      make TQM860L_FEC_config
1826c609719bSwdenk	- will configure for a TQM860L at 50MHz with FEC for ethernet
1827c609719bSwdenk
1828c609719bSwdenk      make TQM860L_80MHz_config
1829c609719bSwdenk	- will configure for a TQM860L at 80 MHz, with normal 10baseT
1830c609719bSwdenk	  interface
1831c609719bSwdenk
1832c609719bSwdenk      make TQM860L_FEC_80MHz_config
1833c609719bSwdenk	- will configure for a TQM860L at 80 MHz with FEC for ethernet
1834c609719bSwdenk
1835c609719bSwdenk      make TQM823L_LCD_config
1836c609719bSwdenk	- will configure for a TQM823L with U-Boot console on LCD
1837c609719bSwdenk
1838c609719bSwdenk      make TQM823L_LCD_80MHz_config
1839c609719bSwdenk	- will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1840c609719bSwdenk
1841c609719bSwdenk      etc.
1842c609719bSwdenk
1843c609719bSwdenk
1844c609719bSwdenk
1845c609719bSwdenkFinally, type "make all", and you should get some working U-Boot
1846c609719bSwdenkimages ready for downlod to / installation on your system:
1847c609719bSwdenk
1848c609719bSwdenk- "u-boot.bin" is a raw binary image
1849c609719bSwdenk- "u-boot" is an image in ELF binary format
1850c609719bSwdenk- "u-boot.srec" is in Motorola S-Record format
1851c609719bSwdenk
1852c609719bSwdenk
1853c609719bSwdenkPlease be aware that the Makefiles assume you are using GNU make, so
1854c609719bSwdenkfor instance on NetBSD you might need to use "gmake" instead of
1855c609719bSwdenknative "make".
1856c609719bSwdenk
1857c609719bSwdenk
1858c609719bSwdenkIf the system board that you have is not listed, then you will need
1859c609719bSwdenkto port U-Boot to your hardware platform. To do this, follow these
1860c609719bSwdenksteps:
1861c609719bSwdenk
1862c609719bSwdenk1.  Add a new configuration option for your board to the toplevel
186385ec0bccSwdenk    "Makefile" and to the "MAKEALL" script, using the existing
186485ec0bccSwdenk    entries as examples. Note that here and at many other places
186585ec0bccSwdenk    boards and other names are listed alphabetically sorted. Please
186685ec0bccSwdenk    keep this order.
1867c609719bSwdenk2.  Create a new directory to hold your board specific code. Add any
186885ec0bccSwdenk    files you need. In your board directory, you will need at least
186985ec0bccSwdenk    the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
187085ec0bccSwdenk3.  Create a new configuration file "include/configs/<board>.h" for
187185ec0bccSwdenk    your board
1872c609719bSwdenk3.  If you're porting U-Boot to a new CPU, then also create a new
1873c609719bSwdenk    directory to hold your CPU specific code. Add any files you need.
187485ec0bccSwdenk4.  Run "make <board>_config" with your new name.
1875c609719bSwdenk5.  Type "make", and you should get a working "u-boot.srec" file
1876c609719bSwdenk    to be installed on your target system.
187785ec0bccSwdenk6.  Debug and solve any problems that might arise.
1878c609719bSwdenk    [Of course, this last step is much harder than it sounds.]
1879c609719bSwdenk
1880c609719bSwdenk
1881c609719bSwdenkTesting of U-Boot Modifications, Ports to New Hardware, etc.:
1882c609719bSwdenk==============================================================
1883c609719bSwdenk
1884c609719bSwdenkIf you have modified U-Boot sources (for instance added a new	board
1885c609719bSwdenkor  support  for  new  devices,	 a new CPU, etc.) you are expected to
1886c609719bSwdenkprovide feedback to the other developers. The feedback normally takes
1887c609719bSwdenkthe form of a "patch", i. e. a context diff against a certain (latest
1888c609719bSwdenkofficial or latest in CVS) version of U-Boot sources.
1889c609719bSwdenk
1890c609719bSwdenkBut before you submit such a patch, please verify that	your  modifi-
1891c609719bSwdenkcation	did not break existing code. At least make sure that *ALL* of
1892c609719bSwdenkthe supported boards compile WITHOUT ANY compiler warnings. To do so,
1893c609719bSwdenkjust run the "MAKEALL" script, which will configure and build U-Boot
1894c609719bSwdenkfor ALL supported system. Be warned, this will take a while. You  can
1895c609719bSwdenkselect	which  (cross)	compiler  to use py passing a `CROSS_COMPILE'
1896c609719bSwdenkenvironment variable to the script, i. e. to use the cross tools from
1897c609719bSwdenkMontaVista's Hard Hat Linux you can type
1898c609719bSwdenk
1899c609719bSwdenk	CROSS_COMPILE=ppc_8xx- MAKEALL
1900c609719bSwdenk
1901c609719bSwdenkor to build on a native PowerPC system you can type
1902c609719bSwdenk
1903c609719bSwdenk	CROSS_COMPILE=' ' MAKEALL
1904c609719bSwdenk
1905c609719bSwdenkSee also "U-Boot Porting Guide" below.
1906c609719bSwdenk
1907c609719bSwdenk
1908c609719bSwdenk
1909c609719bSwdenkMonitor Commands - Overview:
1910c609719bSwdenk============================
1911c609719bSwdenk
1912c609719bSwdenkgo	- start application at address 'addr'
1913c609719bSwdenkrun	- run commands in an environment variable
1914c609719bSwdenkbootm	- boot application image from memory
1915c609719bSwdenkbootp	- boot image via network using BootP/TFTP protocol
1916c609719bSwdenktftpboot- boot image via network using TFTP protocol
1917c609719bSwdenk	       and env variables "ipaddr" and "serverip"
1918c609719bSwdenk	       (and eventually "gatewayip")
1919c609719bSwdenkrarpboot- boot image via network using RARP/TFTP protocol
1920c609719bSwdenkdiskboot- boot from IDE devicebootd   - boot default, i.e., run 'bootcmd'
1921c609719bSwdenkloads	- load S-Record file over serial line
1922c609719bSwdenkloadb	- load binary file over serial line (kermit mode)
1923c609719bSwdenkmd	- memory display
1924c609719bSwdenkmm	- memory modify (auto-incrementing)
1925c609719bSwdenknm	- memory modify (constant address)
1926c609719bSwdenkmw	- memory write (fill)
1927c609719bSwdenkcp	- memory copy
1928c609719bSwdenkcmp	- memory compare
1929c609719bSwdenkcrc32	- checksum calculation
1930c609719bSwdenkimd     - i2c memory display
1931c609719bSwdenkimm     - i2c memory modify (auto-incrementing)
1932c609719bSwdenkinm     - i2c memory modify (constant address)
1933c609719bSwdenkimw     - i2c memory write (fill)
1934c609719bSwdenkicrc32  - i2c checksum calculation
1935c609719bSwdenkiprobe  - probe to discover valid I2C chip addresses
1936c609719bSwdenkiloop   - infinite loop on address range
1937c609719bSwdenkisdram  - print SDRAM configuration information
1938c609719bSwdenksspi    - SPI utility commands
1939c609719bSwdenkbase	- print or set address offset
1940c609719bSwdenkprintenv- print environment variables
1941c609719bSwdenksetenv	- set environment variables
1942c609719bSwdenksaveenv - save environment variables to persistent storage
1943c609719bSwdenkprotect - enable or disable FLASH write protection
1944c609719bSwdenkerase	- erase FLASH memory
1945c609719bSwdenkflinfo	- print FLASH memory information
1946c609719bSwdenkbdinfo	- print Board Info structure
1947c609719bSwdenkiminfo	- print header information for application image
1948c609719bSwdenkconinfo - print console devices and informations
1949c609719bSwdenkide	- IDE sub-system
1950c609719bSwdenkloop	- infinite loop on address range
1951c609719bSwdenkmtest	- simple RAM test
1952c609719bSwdenkicache	- enable or disable instruction cache
1953c609719bSwdenkdcache	- enable or disable data cache
1954c609719bSwdenkreset	- Perform RESET of the CPU
1955c609719bSwdenkecho	- echo args to console
1956c609719bSwdenkversion - print monitor version
1957c609719bSwdenkhelp	- print online help
1958c609719bSwdenk?	- alias for 'help'
1959c609719bSwdenk
1960c609719bSwdenk
1961c609719bSwdenkMonitor Commands - Detailed Description:
1962c609719bSwdenk========================================
1963c609719bSwdenk
1964c609719bSwdenkTODO.
1965c609719bSwdenk
1966c609719bSwdenkFor now: just type "help <command>".
1967c609719bSwdenk
1968c609719bSwdenk
1969c609719bSwdenkEnvironment Variables:
1970c609719bSwdenk======================
1971c609719bSwdenk
1972c609719bSwdenkU-Boot supports user configuration using Environment Variables which
1973c609719bSwdenkcan be made persistent by saving to Flash memory.
1974c609719bSwdenk
1975c609719bSwdenkEnvironment Variables are set using "setenv", printed using
1976c609719bSwdenk"printenv", and saved to Flash using "saveenv". Using "setenv"
1977c609719bSwdenkwithout a value can be used to delete a variable from the
1978c609719bSwdenkenvironment. As long as you don't save the environment you are
1979c609719bSwdenkworking with an in-memory copy. In case the Flash area containing the
1980c609719bSwdenkenvironment is erased by accident, a default environment is provided.
1981c609719bSwdenk
1982c609719bSwdenkSome configuration options can be set using Environment Variables:
1983c609719bSwdenk
1984c609719bSwdenk  baudrate	- see CONFIG_BAUDRATE
1985c609719bSwdenk
1986c609719bSwdenk  bootdelay	- see CONFIG_BOOTDELAY
1987c609719bSwdenk
1988c609719bSwdenk  bootcmd	- see CONFIG_BOOTCOMMAND
1989c609719bSwdenk
1990c609719bSwdenk  bootargs	- Boot arguments when booting an RTOS image
1991c609719bSwdenk
1992c609719bSwdenk  bootfile	- Name of the image to load with TFTP
1993c609719bSwdenk
1994c609719bSwdenk  autoload	- if set to "no" (any string beginning with 'n'),
1995c609719bSwdenk		  "bootp" will just load perform a lookup of the
1996c609719bSwdenk		  configuration from the BOOTP server, but not try to
1997c609719bSwdenk		  load any image using TFTP
1998c609719bSwdenk
1999c609719bSwdenk  autostart	- if set to "yes", an image loaded using the "bootp",
2000c609719bSwdenk		  "rarpboot", "tftpboot" or "diskboot" commands will
2001c609719bSwdenk		  be automatically started (by internally calling
2002c609719bSwdenk		  "bootm")
2003c609719bSwdenk
20044a6fd34bSwdenk		  If set to "no", a standalone image passed to the
20054a6fd34bSwdenk		  "bootm" command will be copied to the load address
20064a6fd34bSwdenk		  (and eventually uncompressed), but NOT be started.
20074a6fd34bSwdenk		  This can be used to load and uncompress arbitrary
20084a6fd34bSwdenk		  data.
20094a6fd34bSwdenk
2010c609719bSwdenk  initrd_high	- restrict positioning of initrd images:
2011c609719bSwdenk		  If this variable is not set, initrd images will be
2012c609719bSwdenk		  copied to the highest possible address in RAM; this
2013c609719bSwdenk		  is usually what you want since it allows for
2014c609719bSwdenk		  maximum initrd size. If for some reason you want to
2015c609719bSwdenk		  make sure that the initrd image is loaded below the
2016c609719bSwdenk		  CFG_BOOTMAPSZ limit, you can set this environment
2017c609719bSwdenk		  variable to a value of "no" or "off" or "0".
2018c609719bSwdenk		  Alternatively, you can set it to a maximum upper
2019c609719bSwdenk		  address to use (U-Boot will still check that it
2020c609719bSwdenk		  does not overwrite the U-Boot stack and data).
2021c609719bSwdenk
2022c609719bSwdenk		  For instance, when you have a system with 16 MB
2023c609719bSwdenk		  RAM, and want to reseve 4 MB from use by Linux,
2024c609719bSwdenk		  you can do this by adding "mem=12M" to the value of
2025c609719bSwdenk		  the "bootargs" variable. However, now you must make
2026c609719bSwdenk		  sure, that the initrd image is placed in the first
2027c609719bSwdenk		  12 MB as well - this can be done with
2028c609719bSwdenk
2029c609719bSwdenk		  setenv initrd_high 00c00000
2030c609719bSwdenk
203138b99261Swdenk                  If you set initrd_high to 0xFFFFFFFF, this is an
203238b99261Swdenk                  indication to U-Boot that all addresses are legal
203338b99261Swdenk                  for the Linux kernel, including addresses in flash
203438b99261Swdenk                  memory. In this case U-Boot will NOT COPY the
203538b99261Swdenk                  ramdisk at all. This may be useful to reduce the
203638b99261Swdenk                  boot time on your system, but requires that this
203738b99261Swdenk                  feature is supported by your Linux kernel.
203838b99261Swdenk
2039c609719bSwdenk  ipaddr	- IP address; needed for tftpboot command
2040c609719bSwdenk
2041c609719bSwdenk  loadaddr	- Default load address for commands like "bootp",
2042dc7c9a1aSwdenk		  "rarpboot", "tftpboot", "loadb" or "diskboot"
2043c609719bSwdenk
2044c609719bSwdenk  loads_echo	- see CONFIG_LOADS_ECHO
2045c609719bSwdenk
2046c609719bSwdenk  serverip	- TFTP server IP address; needed for tftpboot command
2047c609719bSwdenk
2048c609719bSwdenk  bootretry	- see CONFIG_BOOT_RETRY_TIME
2049c609719bSwdenk
2050c609719bSwdenk  bootdelaykey	- see CONFIG_AUTOBOOT_DELAY_STR
2051c609719bSwdenk
2052c609719bSwdenk  bootstopkey	- see CONFIG_AUTOBOOT_STOP_STR
2053c609719bSwdenk
2054c609719bSwdenk
2055c609719bSwdenkThe following environment variables may be used and automatically
2056c609719bSwdenkupdated by the network boot commands ("bootp" and "rarpboot"),
2057c609719bSwdenkdepending the information provided by your boot server:
2058c609719bSwdenk
2059c609719bSwdenk  bootfile	- see above
2060c609719bSwdenk  dnsip		- IP address of your Domain Name Server
2061c609719bSwdenk  gatewayip	- IP address of the Gateway (Router) to use
2062c609719bSwdenk  hostname	- Target hostname
2063c609719bSwdenk  ipaddr	- see above
2064c609719bSwdenk  netmask	- Subnet Mask
2065c609719bSwdenk  rootpath	- Pathname of the root filesystem on the NFS server
2066c609719bSwdenk  serverip	- see above
2067c609719bSwdenk
2068c609719bSwdenk
2069c609719bSwdenkThere are two special Environment Variables:
2070c609719bSwdenk
2071c609719bSwdenk  serial#	- contains hardware identification information such
2072c609719bSwdenk		  as type string and/or serial number
2073c609719bSwdenk  ethaddr	- Ethernet address
2074c609719bSwdenk
2075c609719bSwdenkThese variables can be set only once (usually during manufacturing of
2076c609719bSwdenkthe board). U-Boot refuses to delete or overwrite these variables
2077c609719bSwdenkonce they have been set once.
2078c609719bSwdenk
2079c609719bSwdenk
2080c1551ea8SstroeseFurther special Environment Variables:
2081c1551ea8Sstroese
2082c1551ea8Sstroese  ver		- Contains the U-Boot version string as printed
2083c1551ea8Sstroese		  with the "version" command. This variable is
2084c1551ea8Sstroese		  readonly (see CONFIG_VERSION_VARIABLE).
2085c1551ea8Sstroese
2086c1551ea8Sstroese
2087c609719bSwdenkPlease note that changes to some configuration parameters may take
2088c609719bSwdenkonly effect after the next boot (yes, that's just like Windoze :-).
2089c609719bSwdenk
2090c609719bSwdenk
2091f07771ccSwdenkCommand Line Parsing:
2092f07771ccSwdenk=====================
2093f07771ccSwdenk
2094f07771ccSwdenkThere are two different command line parsers available  with  U-Boot:
2095f07771ccSwdenkthe old "simple" one, and the much more pwerful "hush" shell:
2096f07771ccSwdenk
2097f07771ccSwdenkOld, simple command line parser:
2098f07771ccSwdenk--------------------------------
2099f07771ccSwdenk
2100f07771ccSwdenk- supports environment variables (through setenv / saveenv commands)
2101f07771ccSwdenk- several commands on one line, separated by ';'
2102f07771ccSwdenk- variable substitution using "... $(name) ..." syntax
2103f07771ccSwdenk- special characters ('$', ';') can be escaped by prefixing with '\',
2104f07771ccSwdenk  for example:
2105f07771ccSwdenk	setenv bootcmd bootm \$(address)
2106f07771ccSwdenk- You can also escape text by enclosing in single apostrophes, for example:
2107f07771ccSwdenk	setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2108f07771ccSwdenk
2109f07771ccSwdenkHush shell:
2110f07771ccSwdenk-----------
2111f07771ccSwdenk
2112f07771ccSwdenk- similar to Bourne shell, with control structures like
2113f07771ccSwdenk  if...then...else...fi, for...do...done; while...do...done,
2114f07771ccSwdenk  until...do...done, ...
2115f07771ccSwdenk- supports environment ("global") variables (through setenv / saveenv
2116f07771ccSwdenk  commands) and local shell variables (through standard shell syntax
2117f07771ccSwdenk  "name=value"); only environment variables can be used with "run"
2118f07771ccSwdenk  command
2119f07771ccSwdenk
2120f07771ccSwdenkGeneral rules:
2121f07771ccSwdenk--------------
2122f07771ccSwdenk
2123f07771ccSwdenk(1) If a command line (or an environment variable executed by a "run"
2124f07771ccSwdenk    command) contains several commands separated by semicolon, and
2125f07771ccSwdenk    one of these commands fails, then the remaining commands will be
2126f07771ccSwdenk    executed anyway.
2127f07771ccSwdenk
2128f07771ccSwdenk(2) If you execute several variables with one call to run (i. e.
2129f07771ccSwdenk    calling run with a list af variables as arguments), any failing
2130f07771ccSwdenk    command will cause "run" to terminate, i. e. the remaining
2131f07771ccSwdenk    variables are not executed.
2132f07771ccSwdenk
2133c609719bSwdenkNote for Redundant Ethernet Interfaces:
2134c609719bSwdenk=======================================
2135c609719bSwdenk
2136c609719bSwdenkSome boards come with redundand ethernet interfaces; U-Boot supports
2137c609719bSwdenksuch configurations and is capable of automatic selection of a
2138c609719bSwdenk"working" interface when needed. MAC assignemnt works as follows:
2139c609719bSwdenk
2140c609719bSwdenkNetwork interfaces are numbered eth0, eth1, eth2, ... Corresponding
2141c609719bSwdenkMAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2142c609719bSwdenk"eth1addr" (=>eth1), "eth2addr", ...
2143c609719bSwdenk
2144c609719bSwdenkIf the network interface stores some valid MAC address (for instance
2145c609719bSwdenkin SROM), this is used as default address if there is NO correspon-
2146c609719bSwdenkding setting in the environment; if the corresponding environment
2147c609719bSwdenkvariable is set, this overrides the settings in the card; that means:
2148c609719bSwdenk
2149c609719bSwdenko If the SROM has a valid MAC address, and there is no address in the
2150c609719bSwdenk  environment, the SROM's address is used.
2151c609719bSwdenk
2152c609719bSwdenko If there is no valid address in the SROM, and a definition in the
2153c609719bSwdenk  environment exists, then the value from the environment variable is
2154c609719bSwdenk  used.
2155c609719bSwdenk
2156c609719bSwdenko If both the SROM and the environment contain a MAC address, and
2157c609719bSwdenk  both addresses are the same, this MAC address is used.
2158c609719bSwdenk
2159c609719bSwdenko If both the SROM and the environment contain a MAC address, and the
2160c609719bSwdenk  addresses differ, the value from the environment is used and a
2161c609719bSwdenk  warning is printed.
2162c609719bSwdenk
2163c609719bSwdenko If neither SROM nor the environment contain a MAC address, an error
2164c609719bSwdenk  is raised.
2165c609719bSwdenk
2166c609719bSwdenk
2167c609719bSwdenk
2168c609719bSwdenkImage Formats:
2169c609719bSwdenk==============
2170c609719bSwdenk
2171c609719bSwdenkThe "boot" commands of this monitor operate on "image" files which
2172c609719bSwdenkcan be basicly anything, preceeded by a special header; see the
2173c609719bSwdenkdefinitions in include/image.h for details; basicly, the header
2174c609719bSwdenkdefines the following image properties:
2175c609719bSwdenk
2176c609719bSwdenk* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2177c609719bSwdenk  4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
21787f70e853Swdenk  LynxOS, pSOS, QNX, RTEMS, ARTOS;
21797f70e853Swdenk  Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS).
2180c609719bSwdenk* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2181c609719bSwdenk  IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2182c609719bSwdenk  Currently supported: PowerPC).
2183c609719bSwdenk* Compression Type (Provisions for uncompressed, gzip, bzip2;
2184c609719bSwdenk  Currently supported: uncompressed, gzip).
2185c609719bSwdenk* Load Address
2186c609719bSwdenk* Entry Point
2187c609719bSwdenk* Image Name
2188c609719bSwdenk* Image Timestamp
2189c609719bSwdenk
2190c609719bSwdenkThe header is marked by a special Magic Number, and both the header
2191c609719bSwdenkand the data portions of the image are secured against corruption by
2192c609719bSwdenkCRC32 checksums.
2193c609719bSwdenk
2194c609719bSwdenk
2195c609719bSwdenkLinux Support:
2196c609719bSwdenk==============
2197c609719bSwdenk
2198c609719bSwdenkAlthough U-Boot should support any OS or standalone application
2199c609719bSwdenkeasily, Linux has always been in the focus during the design of
2200c609719bSwdenkU-Boot.
2201c609719bSwdenk
2202c609719bSwdenkU-Boot includes many features that so far have been part of some
2203c609719bSwdenkspecial "boot loader" code within the Linux kernel. Also, any
2204c609719bSwdenk"initrd" images to be used are no longer part of one big Linux image;
2205c609719bSwdenkinstead, kernel and "initrd" are separate images. This implementation
2206c609719bSwdenkserves serveral purposes:
2207c609719bSwdenk
2208c609719bSwdenk- the same features can be used for other OS or standalone
2209c609719bSwdenk  applications (for instance: using compressed images to reduce the
2210c609719bSwdenk  Flash memory footprint)
2211c609719bSwdenk
2212c609719bSwdenk- it becomes much easier to port new Linux kernel versions because
2213c609719bSwdenk  lots of low-level, hardware dependend stuff are done by U-Boot
2214c609719bSwdenk
2215c609719bSwdenk- the same Linux kernel image can now be used with different "initrd"
2216c609719bSwdenk  images; of course this also means that different kernel images can
2217c609719bSwdenk  be run with the same "initrd". This makes testing easier (you don't
2218c609719bSwdenk  have to build a new "zImage.initrd" Linux image when you just
2219c609719bSwdenk  change a file in your "initrd"). Also, a field-upgrade of the
2220c609719bSwdenk  software is easier now.
2221c609719bSwdenk
2222c609719bSwdenk
2223c609719bSwdenkLinux HOWTO:
2224c609719bSwdenk============
2225c609719bSwdenk
2226c609719bSwdenkPorting Linux to U-Boot based systems:
2227c609719bSwdenk---------------------------------------
2228c609719bSwdenk
2229c609719bSwdenkU-Boot cannot save you from doing all the necessary modifications to
2230c609719bSwdenkconfigure the Linux device drivers for use with your target hardware
2231c609719bSwdenk(no, we don't intend to provide a full virtual machine interface to
2232c609719bSwdenkLinux :-).
2233c609719bSwdenk
2234c609719bSwdenkBut now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2235c609719bSwdenk
2236c609719bSwdenkJust make sure your machine specific header file (for instance
2237c609719bSwdenkinclude/asm-ppc/tqm8xx.h) includes the same definition of the Board
2238c609719bSwdenkInformation structure as we define in include/u-boot.h, and make
2239c609719bSwdenksure that your definition of IMAP_ADDR uses the same value as your
2240c609719bSwdenkU-Boot configuration in CFG_IMMR.
2241c609719bSwdenk
2242c609719bSwdenk
2243c609719bSwdenkConfiguring the Linux kernel:
2244c609719bSwdenk-----------------------------
2245c609719bSwdenk
2246c609719bSwdenkNo specific requirements for U-Boot. Make sure you have some root
2247c609719bSwdenkdevice (initial ramdisk, NFS) for your target system.
2248c609719bSwdenk
2249c609719bSwdenk
2250c609719bSwdenkBuilding a Linux Image:
2251c609719bSwdenk-----------------------
2252c609719bSwdenk
225324ee89b9SwdenkWith U-Boot, "normal" build targets like "zImage" or "bzImage" are
225424ee89b9Swdenknot used. If you use recent kernel source, a new build target
225524ee89b9Swdenk"uImage" will exist which automatically builds an image usable by
225624ee89b9SwdenkU-Boot. Most older kernels also have support for a "pImage" target,
225724ee89b9Swdenkwhich was introduced for our predecessor project PPCBoot and uses a
225824ee89b9Swdenk100% compatible format.
2259c609719bSwdenk
2260c609719bSwdenkExample:
2261c609719bSwdenk
2262c609719bSwdenk	make TQM850L_config
2263c609719bSwdenk	make oldconfig
2264c609719bSwdenk	make dep
226524ee89b9Swdenk	make uImage
2266c609719bSwdenk
226724ee89b9SwdenkThe "uImage" build target uses a special tool (in 'tools/mkimage') to
226824ee89b9Swdenkencapsulate a compressed Linux kernel image with header  information,
226924ee89b9SwdenkCRC32 checksum etc. for use with U-Boot. This is what we are doing:
2270c609719bSwdenk
227124ee89b9Swdenk* build a standard "vmlinux" kernel image (in ELF binary format):
227224ee89b9Swdenk
227324ee89b9Swdenk* convert the kernel into a raw binary image:
227424ee89b9Swdenk
227524ee89b9Swdenk	${CROSS_COMPILE}-objcopy -O binary \
227624ee89b9Swdenk				 -R .note -R .comment \
227724ee89b9Swdenk				 -S vmlinux linux.bin
227824ee89b9Swdenk
227924ee89b9Swdenk* compress the binary image:
228024ee89b9Swdenk
228124ee89b9Swdenk	gzip -9 linux.bin
228224ee89b9Swdenk
228324ee89b9Swdenk* package compressed binary image for U-Boot:
228424ee89b9Swdenk
228524ee89b9Swdenk	mkimage -A ppc -O linux -T kernel -C gzip \
228624ee89b9Swdenk		-a 0 -e 0 -n "Linux Kernel Image" \
228724ee89b9Swdenk		-d linux.bin.gz uImage
228824ee89b9Swdenk
228924ee89b9Swdenk
229024ee89b9SwdenkThe "mkimage" tool can also be used to create ramdisk images for use
229124ee89b9Swdenkwith U-Boot, either separated from the Linux kernel image, or
229224ee89b9Swdenkcombined into one file. "mkimage" encapsulates the images with a 64
229324ee89b9Swdenkbyte header containing information about target architecture,
229424ee89b9Swdenkoperating system, image type, compression method, entry points, time
229524ee89b9Swdenkstamp, CRC32 checksums, etc.
229624ee89b9Swdenk
229724ee89b9Swdenk"mkimage" can be called in two ways: to verify existing images and
229824ee89b9Swdenkprint the header information, or to build new images.
2299c609719bSwdenk
2300c609719bSwdenkIn the first form (with "-l" option) mkimage lists the information
2301c609719bSwdenkcontained in the header of an existing U-Boot image; this includes
2302c609719bSwdenkchecksum verification:
2303c609719bSwdenk
2304c609719bSwdenk	tools/mkimage -l image
2305c609719bSwdenk	  -l ==> list image header information
2306c609719bSwdenk
2307c609719bSwdenkThe second form (with "-d" option) is used to build a U-Boot image
2308c609719bSwdenkfrom a "data file" which is used as image payload:
2309c609719bSwdenk
2310c609719bSwdenk	tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2311c609719bSwdenk		      -n name -d data_file image
2312c609719bSwdenk	  -A ==> set architecture to 'arch'
2313c609719bSwdenk	  -O ==> set operating system to 'os'
2314c609719bSwdenk	  -T ==> set image type to 'type'
2315c609719bSwdenk	  -C ==> set compression type 'comp'
2316c609719bSwdenk	  -a ==> set load address to 'addr' (hex)
2317c609719bSwdenk	  -e ==> set entry point to 'ep' (hex)
2318c609719bSwdenk	  -n ==> set image name to 'name'
2319c609719bSwdenk	  -d ==> use image data from 'datafile'
2320c609719bSwdenk
2321c609719bSwdenkRight now, all Linux kernels use the same load address	(0x00000000),
2322c609719bSwdenkbut the entry point address depends on the kernel version:
2323c609719bSwdenk
2324c609719bSwdenk- 2.2.x kernels have the entry point at 0x0000000C,
232524ee89b9Swdenk- 2.3.x and later kernels have the entry point at 0x00000000.
2326c609719bSwdenk
2327c609719bSwdenkSo a typical call to build a U-Boot image would read:
2328c609719bSwdenk
232924ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
233024ee89b9Swdenk	> -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
233124ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
233224ee89b9Swdenk	> examples/uImage.TQM850L
233324ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2334c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2335c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2336c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2337c609719bSwdenk	Load Address: 0x00000000
233824ee89b9Swdenk	Entry Point:  0x00000000
2339c609719bSwdenk
2340c609719bSwdenkTo verify the contents of the image (or check for corruption):
2341c609719bSwdenk
234224ee89b9Swdenk	-> tools/mkimage -l examples/uImage.TQM850L
234324ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2344c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2345c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2346c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2347c609719bSwdenk	Load Address: 0x00000000
234824ee89b9Swdenk	Entry Point:  0x00000000
2349c609719bSwdenk
2350c609719bSwdenkNOTE: for embedded systems where boot time is critical you can trade
2351c609719bSwdenkspeed for memory and install an UNCOMPRESSED image instead: this
2352c609719bSwdenkneeds more space in Flash, but boots much faster since it does not
2353c609719bSwdenkneed to be uncompressed:
2354c609719bSwdenk
235524ee89b9Swdenk	-> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
235624ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
235724ee89b9Swdenk	> -A ppc -O linux -T kernel -C none -a 0 -e 0 \
235824ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
235924ee89b9Swdenk	> examples/uImage.TQM850L-uncompressed
236024ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2361c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2362c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (uncompressed)
2363c609719bSwdenk	Data Size:    792160 Bytes = 773.59 kB = 0.76 MB
2364c609719bSwdenk	Load Address: 0x00000000
236524ee89b9Swdenk	Entry Point:  0x00000000
2366c609719bSwdenk
2367c609719bSwdenk
2368c609719bSwdenkSimilar you can build U-Boot images from a 'ramdisk.image.gz' file
2369c609719bSwdenkwhen your kernel is intended to use an initial ramdisk:
2370c609719bSwdenk
2371c609719bSwdenk	-> tools/mkimage -n 'Simple Ramdisk Image' \
2372c609719bSwdenk	> -A ppc -O linux -T ramdisk -C gzip \
2373c609719bSwdenk	> -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2374c609719bSwdenk	Image Name:   Simple Ramdisk Image
2375c609719bSwdenk	Created:      Wed Jan 12 14:01:50 2000
2376c609719bSwdenk	Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
2377c609719bSwdenk	Data Size:    566530 Bytes = 553.25 kB = 0.54 MB
2378c609719bSwdenk	Load Address: 0x00000000
2379c609719bSwdenk	Entry Point:  0x00000000
2380c609719bSwdenk
2381c609719bSwdenk
2382c609719bSwdenkInstalling a Linux Image:
2383c609719bSwdenk-------------------------
2384c609719bSwdenk
2385c609719bSwdenkTo downloading a U-Boot image over the serial (console) interface,
2386c609719bSwdenkyou must convert the image to S-Record format:
2387c609719bSwdenk
2388c609719bSwdenk	objcopy -I binary -O srec examples/image examples/image.srec
2389c609719bSwdenk
2390c609719bSwdenkThe 'objcopy' does not understand the information in the U-Boot
2391c609719bSwdenkimage header, so the resulting S-Record file will be relative to
2392c609719bSwdenkaddress 0x00000000. To load it to a given address, you need to
2393c609719bSwdenkspecify the target address as 'offset' parameter with the 'loads'
2394c609719bSwdenkcommand.
2395c609719bSwdenk
2396c609719bSwdenkExample: install the image to address 0x40100000 (which on the
2397c609719bSwdenkTQM8xxL is in the first Flash bank):
2398c609719bSwdenk
2399c609719bSwdenk	=> erase 40100000 401FFFFF
2400c609719bSwdenk
2401c609719bSwdenk	.......... done
2402c609719bSwdenk	Erased 8 sectors
2403c609719bSwdenk
2404c609719bSwdenk	=> loads 40100000
2405c609719bSwdenk	## Ready for S-Record download ...
2406c609719bSwdenk	~>examples/image.srec
2407c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2408c609719bSwdenk	...
2409c609719bSwdenk	15989 15990 15991 15992
2410c609719bSwdenk	[file transfer complete]
2411c609719bSwdenk	[connected]
2412c609719bSwdenk	## Start Addr = 0x00000000
2413c609719bSwdenk
2414c609719bSwdenk
2415c609719bSwdenkYou can check the success of the download using the 'iminfo' command;
2416c609719bSwdenkthis includes a checksum verification so you  can  be  sure  no	 data
2417c609719bSwdenkcorruption happened:
2418c609719bSwdenk
2419c609719bSwdenk	=> imi 40100000
2420c609719bSwdenk
2421c609719bSwdenk	## Checking Image at 40100000 ...
2422c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2423c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2424c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2425c609719bSwdenk	   Load Address: 00000000
2426c609719bSwdenk	   Entry Point:	 0000000c
2427c609719bSwdenk	   Verifying Checksum ... OK
2428c609719bSwdenk
2429c609719bSwdenk
2430c609719bSwdenk
2431c609719bSwdenkBoot Linux:
2432c609719bSwdenk-----------
2433c609719bSwdenk
2434c609719bSwdenkThe "bootm" command is used to boot an application that is stored in
2435c609719bSwdenkmemory (RAM or Flash). In case of a Linux kernel image, the contents
2436c609719bSwdenkof the "bootargs" environment variable is passed to the kernel as
2437c609719bSwdenkparameters. You can check and modify this variable using the
2438c609719bSwdenk"printenv" and "setenv" commands:
2439c609719bSwdenk
2440c609719bSwdenk
2441c609719bSwdenk	=> printenv bootargs
2442c609719bSwdenk	bootargs=root=/dev/ram
2443c609719bSwdenk
2444c609719bSwdenk	=> setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2445c609719bSwdenk
2446c609719bSwdenk	=> printenv bootargs
2447c609719bSwdenk	bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2448c609719bSwdenk
2449c609719bSwdenk	=> bootm 40020000
2450c609719bSwdenk	## Booting Linux kernel at 40020000 ...
2451c609719bSwdenk	   Image Name:	 2.2.13 for NFS on TQM850L
2452c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2453c609719bSwdenk	   Data Size:	 381681 Bytes = 372 kB = 0 MB
2454c609719bSwdenk	   Load Address: 00000000
2455c609719bSwdenk	   Entry Point:	 0000000c
2456c609719bSwdenk	   Verifying Checksum ... OK
2457c609719bSwdenk	   Uncompressing Kernel Image ... OK
2458c609719bSwdenk	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
2459c609719bSwdenk	Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2460c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2461c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2462c609719bSwdenk	Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2463c609719bSwdenk	...
2464c609719bSwdenk
2465c609719bSwdenkIf you want to boot a Linux kernel with initial ram disk, you pass
2466c609719bSwdenkthe memory addreses of both the kernel and the initrd image (PPBCOOT
2467c609719bSwdenkformat!) to the "bootm" command:
2468c609719bSwdenk
2469c609719bSwdenk	=> imi 40100000 40200000
2470c609719bSwdenk
2471c609719bSwdenk	## Checking Image at 40100000 ...
2472c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2473c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2474c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2475c609719bSwdenk	   Load Address: 00000000
2476c609719bSwdenk	   Entry Point:	 0000000c
2477c609719bSwdenk	   Verifying Checksum ... OK
2478c609719bSwdenk
2479c609719bSwdenk	## Checking Image at 40200000 ...
2480c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2481c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2482c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2483c609719bSwdenk	   Load Address: 00000000
2484c609719bSwdenk	   Entry Point:	 00000000
2485c609719bSwdenk	   Verifying Checksum ... OK
2486c609719bSwdenk
2487c609719bSwdenk	=> bootm 40100000 40200000
2488c609719bSwdenk	## Booting Linux kernel at 40100000 ...
2489c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2490c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2491c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2492c609719bSwdenk	   Load Address: 00000000
2493c609719bSwdenk	   Entry Point:	 0000000c
2494c609719bSwdenk	   Verifying Checksum ... OK
2495c609719bSwdenk	   Uncompressing Kernel Image ... OK
2496c609719bSwdenk	## Loading RAMDisk Image at 40200000 ...
2497c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2498c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2499c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2500c609719bSwdenk	   Load Address: 00000000
2501c609719bSwdenk	   Entry Point:	 00000000
2502c609719bSwdenk	   Verifying Checksum ... OK
2503c609719bSwdenk	   Loading Ramdisk ... OK
2504c609719bSwdenk	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
2505c609719bSwdenk	Boot arguments: root=/dev/ram
2506c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2507c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2508c609719bSwdenk	...
2509c609719bSwdenk	RAMDISK: Compressed image found at block 0
2510c609719bSwdenk	VFS: Mounted root (ext2 filesystem).
2511c609719bSwdenk
2512c609719bSwdenk	bash#
2513c609719bSwdenk
25146069ff26SwdenkMore About U-Boot Image Types:
25156069ff26Swdenk------------------------------
25166069ff26Swdenk
25176069ff26SwdenkU-Boot supports the following image types:
25186069ff26Swdenk
25196069ff26Swdenk   "Standalone Programs" are directly runnable in the environment
25206069ff26Swdenk  	provided by U-Boot; it is expected that (if they behave
25216069ff26Swdenk  	well) you can continue to work in U-Boot after return from
25226069ff26Swdenk  	the Standalone Program.
25236069ff26Swdenk   "OS Kernel Images" are usually images of some Embedded OS which
25246069ff26Swdenk  	will take over control completely. Usually these programs
25256069ff26Swdenk  	will install their own set of exception handlers, device
25266069ff26Swdenk  	drivers, set up the MMU, etc. - this means, that you cannot
25276069ff26Swdenk  	expect to re-enter U-Boot except by resetting the CPU.
25286069ff26Swdenk   "RAMDisk Images" are more or less just data blocks, and their
25296069ff26Swdenk  	parameters (address, size) are passed to an OS kernel that is
25306069ff26Swdenk  	being started.
25316069ff26Swdenk   "Multi-File Images" contain several images, typically an OS
25326069ff26Swdenk  	(Linux) kernel image and one or more data images like
25336069ff26Swdenk  	RAMDisks. This construct is useful for instance when you want
25346069ff26Swdenk  	to boot over the network using BOOTP etc., where the boot
25356069ff26Swdenk  	server provides just a single image file, but you want to get
25366069ff26Swdenk  	for instance an OS kernel and a RAMDisk image.
25376069ff26Swdenk
25386069ff26Swdenk  	"Multi-File Images" start with a list of image sizes, each
25396069ff26Swdenk  	image size (in bytes) specified by an "uint32_t" in network
25406069ff26Swdenk  	byte order. This list is terminated by an "(uint32_t)0".
25416069ff26Swdenk  	Immediately after the terminating 0 follow the images, one by
25426069ff26Swdenk  	one, all aligned on "uint32_t" boundaries (size rounded up to
25436069ff26Swdenk  	a multiple of 4 bytes).
25446069ff26Swdenk
25456069ff26Swdenk   "Firmware Images" are binary images containing firmware (like
25466069ff26Swdenk  	U-Boot or FPGA images) which usually will be programmed to
25476069ff26Swdenk  	flash memory.
25486069ff26Swdenk
25496069ff26Swdenk   "Script files" are command sequences that will be executed by
25506069ff26Swdenk  	U-Boot's command interpreter; this feature is especially
25516069ff26Swdenk  	useful when you configure U-Boot to use a real shell (hush)
25526069ff26Swdenk  	as command interpreter.
25536069ff26Swdenk
2554c609719bSwdenk
2555c609719bSwdenkStandalone HOWTO:
2556c609719bSwdenk=================
2557c609719bSwdenk
2558c609719bSwdenkOne of the features of U-Boot is that you can dynamically load and
2559c609719bSwdenkrun "standalone" applications, which can use some resources of
2560c609719bSwdenkU-Boot like console I/O functions or interrupt services.
2561c609719bSwdenk
2562c609719bSwdenkTwo simple examples are included with the sources:
2563c609719bSwdenk
2564c609719bSwdenk"Hello World" Demo:
2565c609719bSwdenk-------------------
2566c609719bSwdenk
2567c609719bSwdenk'examples/hello_world.c' contains a small "Hello World" Demo
2568c609719bSwdenkapplication; it is automatically compiled when you build U-Boot.
2569c609719bSwdenkIt's configured to run at address 0x00040004, so you can play with it
2570c609719bSwdenklike that:
2571c609719bSwdenk
2572c609719bSwdenk	=> loads
2573c609719bSwdenk	## Ready for S-Record download ...
2574c609719bSwdenk	~>examples/hello_world.srec
2575c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2576c609719bSwdenk	[file transfer complete]
2577c609719bSwdenk	[connected]
2578c609719bSwdenk	## Start Addr = 0x00040004
2579c609719bSwdenk
2580c609719bSwdenk	=> go 40004 Hello World! This is a test.
2581c609719bSwdenk	## Starting application at 0x00040004 ...
2582c609719bSwdenk	Hello World
2583c609719bSwdenk	argc = 7
2584c609719bSwdenk	argv[0] = "40004"
2585c609719bSwdenk	argv[1] = "Hello"
2586c609719bSwdenk	argv[2] = "World!"
2587c609719bSwdenk	argv[3] = "This"
2588c609719bSwdenk	argv[4] = "is"
2589c609719bSwdenk	argv[5] = "a"
2590c609719bSwdenk	argv[6] = "test."
2591c609719bSwdenk	argv[7] = "<NULL>"
2592c609719bSwdenk	Hit any key to exit ...
2593c609719bSwdenk
2594c609719bSwdenk	## Application terminated, rc = 0x0
2595c609719bSwdenk
2596c609719bSwdenkAnother example, which demonstrates how to register a CPM interrupt
2597c609719bSwdenkhandler with the U-Boot code, can be found in 'examples/timer.c'.
2598c609719bSwdenkHere, a CPM timer is set up to generate an interrupt every second.
2599c609719bSwdenkThe interrupt service routine is trivial, just printing a '.'
2600c609719bSwdenkcharacter, but this is just a demo program. The application can be
2601c609719bSwdenkcontrolled by the following keys:
2602c609719bSwdenk
2603c609719bSwdenk	? - print current values og the CPM Timer registers
2604c609719bSwdenk	b - enable interrupts and start timer
2605c609719bSwdenk	e - stop timer and disable interrupts
2606c609719bSwdenk	q - quit application
2607c609719bSwdenk
2608c609719bSwdenk	=> loads
2609c609719bSwdenk	## Ready for S-Record download ...
2610c609719bSwdenk	~>examples/timer.srec
2611c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2612c609719bSwdenk	[file transfer complete]
2613c609719bSwdenk	[connected]
2614c609719bSwdenk	## Start Addr = 0x00040004
2615c609719bSwdenk
2616c609719bSwdenk	=> go 40004
2617c609719bSwdenk	## Starting application at 0x00040004 ...
2618c609719bSwdenk	TIMERS=0xfff00980
2619c609719bSwdenk	Using timer 1
2620c609719bSwdenk	  tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2621c609719bSwdenk
2622c609719bSwdenkHit 'b':
2623c609719bSwdenk	[q, b, e, ?] Set interval 1000000 us
2624c609719bSwdenk	Enabling timer
2625c609719bSwdenkHit '?':
2626c609719bSwdenk	[q, b, e, ?] ........
2627c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2628c609719bSwdenkHit '?':
2629c609719bSwdenk	[q, b, e, ?] .
2630c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2631c609719bSwdenkHit '?':
2632c609719bSwdenk	[q, b, e, ?] .
2633c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2634c609719bSwdenkHit '?':
2635c609719bSwdenk	[q, b, e, ?] .
2636c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2637c609719bSwdenkHit 'e':
2638c609719bSwdenk	[q, b, e, ?] ...Stopping timer
2639c609719bSwdenkHit 'q':
2640c609719bSwdenk	[q, b, e, ?] ## Application terminated, rc = 0x0
2641c609719bSwdenk
2642c609719bSwdenk
264385ec0bccSwdenk
264485ec0bccSwdenkMinicom warning:
264585ec0bccSwdenk================
264685ec0bccSwdenk
264785ec0bccSwdenkOver time, many people have reported problems when trying to used the
264885ec0bccSwdenk"minicom" terminal emulation program for serial download. I (wd)
264985ec0bccSwdenkconsider minicom to be broken, and recommend not to use it. Under
2650f07771ccSwdenkUnix, I recommend to use C-Kermit for general purpose use (and
265185ec0bccSwdenkespecially for kermit binary protocol download ("loadb" command), and
265285ec0bccSwdenkuse "cu" for S-Record download ("loads" command).
265385ec0bccSwdenk
2654*52f52c14SwdenkNevertheless, if you absolutely want to use it try adding this
2655*52f52c14Swdenkconfiguration to your "File transfer protocols" section:
2656*52f52c14Swdenk
2657*52f52c14Swdenk	   Name    Program                      Name U/D FullScr IO-Red. Multi
2658*52f52c14Swdenk	X  kermit  /usr/bin/kermit -i -l %l -s   Y    U    Y       N      N
2659*52f52c14Swdenk	Y  kermit  /usr/bin/kermit -i -l %l -r   N    D    Y       N      N
2660*52f52c14Swdenk
2661*52f52c14Swdenk
2662c609719bSwdenkNetBSD Notes:
2663c609719bSwdenk=============
2664c609719bSwdenk
2665c609719bSwdenkStarting at version 0.9.2, U-Boot supports NetBSD both as host
2666c609719bSwdenk(build U-Boot) and target system (boots NetBSD/mpc8xx).
2667c609719bSwdenk
2668c609719bSwdenkBuilding requires a cross environment; it is known to work on
2669c609719bSwdenkNetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2670c609719bSwdenkneed gmake since the Makefiles are not compatible with BSD make).
2671c609719bSwdenkNote that the cross-powerpc package does not install include files;
2672c609719bSwdenkattempting to build U-Boot will fail because <machine/ansi.h> is
2673c609719bSwdenkmissing.  This file has to be installed and patched manually:
2674c609719bSwdenk
2675c609719bSwdenk	# cd /usr/pkg/cross/powerpc-netbsd/include
2676c609719bSwdenk	# mkdir powerpc
2677c609719bSwdenk	# ln -s powerpc machine
2678c609719bSwdenk	# cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2679c609719bSwdenk	# ${EDIT} powerpc/ansi.h	## must remove __va_list, _BSD_VA_LIST
2680c609719bSwdenk
2681c609719bSwdenkNative builds *don't* work due to incompatibilities between native
2682c609719bSwdenkand U-Boot include files.
2683c609719bSwdenk
2684c609719bSwdenkBooting assumes that (the first part of) the image booted is a
2685c609719bSwdenkstage-2 loader which in turn loads and then invokes the kernel
2686c609719bSwdenkproper. Loader sources will eventually appear in the NetBSD source
2687c609719bSwdenktree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2688c609719bSwdenkmeantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2689c609719bSwdenkdetails.
2690c609719bSwdenk
2691c609719bSwdenk
2692c609719bSwdenkImplementation Internals:
2693c609719bSwdenk=========================
2694c609719bSwdenk
2695c609719bSwdenkThe following is not intended to be a complete description of every
2696c609719bSwdenkimplementation detail. However, it should help to understand the
2697c609719bSwdenkinner workings of U-Boot and make it easier to port it to custom
2698c609719bSwdenkhardware.
2699c609719bSwdenk
2700c609719bSwdenk
2701c609719bSwdenkInitial Stack, Global Data:
2702c609719bSwdenk---------------------------
2703c609719bSwdenk
2704c609719bSwdenkThe implementation of U-Boot is complicated by the fact that U-Boot
2705c609719bSwdenkstarts running out of ROM (flash memory), usually without access to
2706c609719bSwdenksystem RAM (because the memory controller is not initialized yet).
2707c609719bSwdenkThis means that we don't have writable Data or BSS segments, and BSS
2708c609719bSwdenkis not initialized as zero. To be able to get a C environment working
2709c609719bSwdenkat all, we have to allocate at least a minimal stack. Implementation
2710c609719bSwdenkoptions for this are defined and restricted by the CPU used: Some CPU
2711c609719bSwdenkmodels provide on-chip memory (like the IMMR area on MPC8xx and
2712c609719bSwdenkMPC826x processors), on others (parts of) the data cache can be
2713c609719bSwdenklocked as (mis-) used as memory, etc.
2714c609719bSwdenk
271543d9616cSwdenk	Chris Hallinan posted a good summy of  these  issues  to  the
271643d9616cSwdenk	u-boot-users mailing list:
271743d9616cSwdenk
271843d9616cSwdenk	Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
271943d9616cSwdenk	From: "Chris Hallinan" <clh@net1plus.com>
272043d9616cSwdenk	Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
272143d9616cSwdenk	...
272243d9616cSwdenk
272343d9616cSwdenk	Correct me if I'm wrong, folks, but the way I understand it
272443d9616cSwdenk	is this: Using DCACHE as initial RAM for Stack, etc, does not
272543d9616cSwdenk	require any physical RAM backing up the cache. The cleverness
272643d9616cSwdenk	is that the cache is being used as a temporary supply of
272743d9616cSwdenk	necessary storage before the SDRAM controller is setup. It's
272843d9616cSwdenk	beyond the scope of this list to expain the details, but you
272943d9616cSwdenk	can see how this works by studying the cache architecture and
273043d9616cSwdenk	operation in the architecture and processor-specific manuals.
273143d9616cSwdenk
273243d9616cSwdenk	OCM is On Chip Memory, which I believe the 405GP has 4K. It
273343d9616cSwdenk	is another option for the system designer to use as an
273443d9616cSwdenk	initial stack/ram area prior to SDRAM being available. Either
273543d9616cSwdenk	option should work for you. Using CS 4 should be fine if your
273643d9616cSwdenk	board designers haven't used it for something that would
273743d9616cSwdenk	cause you grief during the initial boot! It is frequently not
273843d9616cSwdenk	used.
273943d9616cSwdenk
274043d9616cSwdenk	CFG_INIT_RAM_ADDR should be somewhere that won't interfere
274143d9616cSwdenk	with your processor/board/system design. The default value
274243d9616cSwdenk	you will find in any recent u-boot distribution in
274343d9616cSwdenk	Walnut405.h should work for you. I'd set it to a value larger
274443d9616cSwdenk	than your SDRAM module. If you have a 64MB SDRAM module, set
274543d9616cSwdenk	it above 400_0000. Just make sure your board has no resources
274643d9616cSwdenk	that are supposed to respond to that address! That code in
274743d9616cSwdenk	start.S has been around a while and should work as is when
274843d9616cSwdenk	you get the config right.
274943d9616cSwdenk
275043d9616cSwdenk	-Chris Hallinan
275143d9616cSwdenk	DS4.COM, Inc.
275243d9616cSwdenk
2753c609719bSwdenkIt is essential to remember this, since it has some impact on the C
2754c609719bSwdenkcode for the initialization procedures:
2755c609719bSwdenk
2756c609719bSwdenk* Initialized global data (data segment) is read-only. Do not attempt
2757c609719bSwdenk  to write it.
2758c609719bSwdenk
2759c609719bSwdenk* Do not use any unitialized global data (or implicitely initialized
2760c609719bSwdenk  as zero data - BSS segment) at all - this is undefined, initiali-
2761c609719bSwdenk  zation is performed later (when relocationg to RAM).
2762c609719bSwdenk
2763c609719bSwdenk* Stack space is very limited. Avoid big data buffers or things  like
2764c609719bSwdenk  that.
2765c609719bSwdenk
2766c609719bSwdenkHaving only the stack as writable memory limits means we cannot use
2767c609719bSwdenknormal global data to share information beween the code. But it
2768c609719bSwdenkturned out that the implementation of U-Boot can be greatly
2769c609719bSwdenksimplified by making a global data structure (gd_t) available to all
2770c609719bSwdenkfunctions. We could pass a pointer to this data as argument to _all_
2771c609719bSwdenkfunctions, but this would bloat the code. Instead we use a feature of
2772c609719bSwdenkthe GCC compiler (Global Register Variables) to share the data: we
2773c609719bSwdenkplace a pointer (gd) to the global data into a register which we
2774c609719bSwdenkreserve for this purpose.
2775c609719bSwdenk
2776c609719bSwdenkWhen chosing a register for such a purpose we are restricted  by  the
2777c609719bSwdenkrelevant  (E)ABI  specifications for the current architecture, and by
2778c609719bSwdenkGCC's implementation.
2779c609719bSwdenk
2780c609719bSwdenkFor PowerPC, the following registers have specific use:
2781c609719bSwdenk	R1:	stack pointer
2782c609719bSwdenk	R2:	TOC pointer
2783c609719bSwdenk	R3-R4:	parameter passing and return values
2784c609719bSwdenk	R5-R10:	parameter passing
2785c609719bSwdenk	R13:	small data area pointer
2786c609719bSwdenk	R30:	GOT pointer
2787c609719bSwdenk	R31:	frame pointer
2788c609719bSwdenk
2789c609719bSwdenk	(U-Boot also uses R14 as internal GOT pointer.)
2790c609719bSwdenk
2791c609719bSwdenk    ==> U-Boot will use R29 to hold a pointer to the global data
2792c609719bSwdenk
2793c609719bSwdenk    Note: on PPC, we could use a static initializer (since the
2794c609719bSwdenk    address of the global data structure is known at compile time),
2795c609719bSwdenk    but it turned out that reserving a register results in somewhat
2796c609719bSwdenk    smaller code - although the code savings are not that big (on
2797c609719bSwdenk    average for all boards 752 bytes for the whole U-Boot image,
2798c609719bSwdenk    624 text + 127 data).
2799c609719bSwdenk
2800c609719bSwdenkOn ARM, the following registers are used:
2801c609719bSwdenk
2802c609719bSwdenk	R0:	function argument word/integer result
2803c609719bSwdenk	R1-R3:	function argument word
2804c609719bSwdenk	R9:	GOT pointer
2805c609719bSwdenk	R10:	stack limit (used only if stack checking if enabled)
2806c609719bSwdenk	R11:	argument (frame) pointer
2807c609719bSwdenk	R12:	temporary workspace
2808c609719bSwdenk	R13:	stack pointer
2809c609719bSwdenk	R14:	link register
2810c609719bSwdenk	R15:	program counter
2811c609719bSwdenk
2812c609719bSwdenk    ==> U-Boot will use R8 to hold a pointer to the global data
2813c609719bSwdenk
2814c609719bSwdenk
2815c609719bSwdenk
2816c609719bSwdenkMemory Management:
2817c609719bSwdenk------------------
2818c609719bSwdenk
2819c609719bSwdenkU-Boot runs in system state and uses physical addresses, i.e. the
2820c609719bSwdenkMMU is not used either for address mapping nor for memory protection.
2821c609719bSwdenk
2822c609719bSwdenkThe available memory is mapped to fixed addresses using the memory
2823c609719bSwdenkcontroller. In this process, a contiguous block is formed for each
2824c609719bSwdenkmemory type (Flash, SDRAM, SRAM), even when it consists of several
2825c609719bSwdenkphysical memory banks.
2826c609719bSwdenk
2827c609719bSwdenkU-Boot is installed in the first 128 kB of the first Flash bank (on
2828c609719bSwdenkTQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2829c609719bSwdenkbooting and sizing and initializing DRAM, the code relocates itself
2830c609719bSwdenkto the upper end of DRAM. Immediately below the U-Boot code some
2831c609719bSwdenkmemory is reserved for use by malloc() [see CFG_MALLOC_LEN
2832c609719bSwdenkconfiguration setting]. Below that, a structure with global Board
2833c609719bSwdenkInfo data is placed, followed by the stack (growing downward).
2834c609719bSwdenk
2835c609719bSwdenkAdditionally, some exception handler code is copied to the low 8 kB
2836c609719bSwdenkof DRAM (0x00000000 ... 0x00001FFF).
2837c609719bSwdenk
2838c609719bSwdenkSo a typical memory configuration with 16 MB of DRAM could look like
2839c609719bSwdenkthis:
2840c609719bSwdenk
2841c609719bSwdenk	0x0000 0000	Exception Vector code
2842c609719bSwdenk	      :
2843c609719bSwdenk	0x0000 1FFF
2844c609719bSwdenk	0x0000 2000	Free for Application Use
2845c609719bSwdenk	      :
2846c609719bSwdenk	      :
2847c609719bSwdenk
2848c609719bSwdenk	      :
2849c609719bSwdenk	      :
2850c609719bSwdenk	0x00FB FF20	Monitor Stack (Growing downward)
2851c609719bSwdenk	0x00FB FFAC	Board Info Data and permanent copy of global data
2852c609719bSwdenk	0x00FC 0000	Malloc Arena
2853c609719bSwdenk	      :
2854c609719bSwdenk	0x00FD FFFF
2855c609719bSwdenk	0x00FE 0000	RAM Copy of Monitor Code
2856c609719bSwdenk	...		eventually: LCD or video framebuffer
2857c609719bSwdenk	...		eventually: pRAM (Protected RAM - unchanged by reset)
2858c609719bSwdenk	0x00FF FFFF	[End of RAM]
2859c609719bSwdenk
2860c609719bSwdenk
2861c609719bSwdenkSystem Initialization:
2862c609719bSwdenk----------------------
2863c609719bSwdenk
2864c609719bSwdenkIn the reset configuration, U-Boot starts at the reset entry point
2865c609719bSwdenk(on most PowerPC systens at address 0x00000100). Because of the reset
2866c609719bSwdenkconfiguration for CS0# this is a mirror of the onboard Flash memory.
2867c609719bSwdenkTo be able to re-map memory U-Boot then jumps to it's link address.
2868c609719bSwdenkTo be able to implement the initialization code in C, a (small!)
2869c609719bSwdenkinitial stack is set up in the internal Dual Ported RAM (in case CPUs
2870c609719bSwdenkwhich provide such a feature like MPC8xx or MPC8260), or in a locked
2871c609719bSwdenkpart of the data cache. After that, U-Boot initializes the CPU core,
2872c609719bSwdenkthe caches and the SIU.
2873c609719bSwdenk
2874c609719bSwdenkNext, all (potentially) available memory banks are mapped using a
2875c609719bSwdenkpreliminary mapping. For example, we put them on 512 MB boundaries
2876c609719bSwdenk(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2877c609719bSwdenkon 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2878c609719bSwdenkprogrammed for SDRAM access. Using the temporary configuration, a
2879c609719bSwdenksimple memory test is run that determines the size of the SDRAM
2880c609719bSwdenkbanks.
2881c609719bSwdenk
2882c609719bSwdenkWhen there is more than one SDRAM bank, and the banks are of
2883c609719bSwdenkdifferent size, the larger is mapped first. For equal size, the first
2884c609719bSwdenkbank (CS2#) is mapped first. The first mapping is always for address
2885c609719bSwdenk0x00000000, with any additional banks following immediately to create
2886c609719bSwdenkcontiguous memory starting from 0.
2887c609719bSwdenk
2888c609719bSwdenkThen, the monitor installs itself at the upper end of the SDRAM area
2889c609719bSwdenkand allocates memory for use by malloc() and for the global Board
2890c609719bSwdenkInfo data; also, the exception vector code is copied to the low RAM
2891c609719bSwdenkpages, and the final stack is set up.
2892c609719bSwdenk
2893c609719bSwdenkOnly after this relocation will you have a "normal" C environment;
2894c609719bSwdenkuntil that you are restricted in several ways, mostly because you are
2895c609719bSwdenkrunning from ROM, and because the code will have to be relocated to a
2896c609719bSwdenknew address in RAM.
2897c609719bSwdenk
2898c609719bSwdenk
2899c609719bSwdenkU-Boot Porting Guide:
2900c609719bSwdenk----------------------
2901c609719bSwdenk
2902c609719bSwdenk[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
29036aff3115Swdenklist, October 2002]
2904c609719bSwdenk
2905c609719bSwdenk
2906c609719bSwdenkint main (int argc, char *argv[])
2907c609719bSwdenk{
2908c609719bSwdenk	sighandler_t no_more_time;
2909c609719bSwdenk
2910c609719bSwdenk	signal (SIGALRM, no_more_time);
2911c609719bSwdenk	alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2912c609719bSwdenk
2913c609719bSwdenk	if (available_money > available_manpower) {
2914c609719bSwdenk		pay consultant to port U-Boot;
2915c609719bSwdenk		return 0;
2916c609719bSwdenk	}
2917c609719bSwdenk
2918c609719bSwdenk	Download latest U-Boot source;
2919c609719bSwdenk
29206aff3115Swdenk	Subscribe to u-boot-users mailing list;
29216aff3115Swdenk
2922c609719bSwdenk	if (clueless) {
2923c609719bSwdenk		email ("Hi, I am new to U-Boot, how do I get started?");
2924c609719bSwdenk	}
2925c609719bSwdenk
2926c609719bSwdenk	while (learning) {
2927c609719bSwdenk		Read the README file in the top level directory;
2928c609719bSwdenk		Read http://www.denx.de/re/DPLG.html
2929c609719bSwdenk		Read the source, Luke;
2930c609719bSwdenk	}
2931c609719bSwdenk
2932c609719bSwdenk	if (available_money > toLocalCurrency ($2500)) {
2933c609719bSwdenk		Buy a BDI2000;
2934c609719bSwdenk	} else {
2935c609719bSwdenk		Add a lot of aggravation and time;
2936c609719bSwdenk	}
2937c609719bSwdenk
2938c609719bSwdenk	Create your own board support subdirectory;
2939c609719bSwdenk
29406aff3115Swdenk	Create your own board config file;
29416aff3115Swdenk
2942c609719bSwdenk	while (!running) {
2943c609719bSwdenk		do {
2944c609719bSwdenk			Add / modify source code;
2945c609719bSwdenk		} until (compiles);
2946c609719bSwdenk		Debug;
2947c609719bSwdenk		if (clueless)
2948c609719bSwdenk			email ("Hi, I am having problems...");
2949c609719bSwdenk	}
2950c609719bSwdenk	Send patch file to Wolfgang;
2951c609719bSwdenk
2952c609719bSwdenk	return 0;
2953c609719bSwdenk}
2954c609719bSwdenk
2955c609719bSwdenkvoid no_more_time (int sig)
2956c609719bSwdenk{
2957c609719bSwdenk      hire_a_guru();
2958c609719bSwdenk}
2959c609719bSwdenk
2960c609719bSwdenk
2961c609719bSwdenk
2962c609719bSwdenkCoding Standards:
2963c609719bSwdenk-----------------
2964c609719bSwdenk
2965c609719bSwdenkAll contributions to U-Boot should conform to the Linux kernel
2966c609719bSwdenkcoding style; see the file "Documentation/CodingStyle" in your Linux
2967c609719bSwdenkkernel source directory.
2968c609719bSwdenk
2969c609719bSwdenkPlease note that U-Boot is implemented in C (and to some small parts
2970c609719bSwdenkin Assembler); no C++ is used, so please do not use C++ style
2971c609719bSwdenkcomments (//) in your code.
2972c609719bSwdenk
2973c609719bSwdenkSubmissions which do not conform to the standards may be returned
2974c609719bSwdenkwith a request to reformat the changes.
2975c609719bSwdenk
2976c609719bSwdenk
2977c609719bSwdenkSubmitting Patches:
2978c609719bSwdenk-------------------
2979c609719bSwdenk
2980c609719bSwdenkSince the number of patches for U-Boot is growing, we need to
2981c609719bSwdenkestablish some rules. Submissions which do not conform to these rules
2982c609719bSwdenkmay be rejected, even when they contain important and valuable stuff.
2983c609719bSwdenk
2984c609719bSwdenk
2985c609719bSwdenkWhen you send a patch, please include the following information with
2986c609719bSwdenkit:
2987c609719bSwdenk
2988c609719bSwdenk* For bug fixes: a description of the bug and how your patch fixes
2989c609719bSwdenk  this bug. Please try to include a way of demonstrating that the
2990c609719bSwdenk  patch actually fixes something.
2991c609719bSwdenk
2992c609719bSwdenk* For new features: a description of the feature and your
2993c609719bSwdenk  implementation.
2994c609719bSwdenk
2995c609719bSwdenk* A CHANGELOG entry as plaintext (separate from the patch)
2996c609719bSwdenk
2997c609719bSwdenk* For major contributions, your entry to the CREDITS file
2998c609719bSwdenk
2999c609719bSwdenk* When you add support for a new board, don't forget to add this
3000c609719bSwdenk  board to the MAKEALL script, too.
3001c609719bSwdenk
3002c609719bSwdenk* If your patch adds new configuration options, don't forget to
3003c609719bSwdenk  document these in the README file.
3004c609719bSwdenk
3005c609719bSwdenk* The patch itself. If you are accessing the CVS repository use "cvs
3006c609719bSwdenk  update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3007c609719bSwdenk  version of diff does not support these options, then get the latest
3008c609719bSwdenk  version of GNU diff.
3009c609719bSwdenk
3010c609719bSwdenk  We accept patches as plain text, MIME attachments or as uuencoded
3011c609719bSwdenk  gzipped text.
3012c609719bSwdenk
3013*52f52c14Swdenk* If one logical set of modifications affects or creates several
3014*52f52c14Swdenk  files, all these changes shall be submitted in a SINGLE patch file.
3015*52f52c14Swdenk
3016*52f52c14Swdenk* Changesets that contain different, unrelated modifications shall be
3017*52f52c14Swdenk  submitted as SEPARATE patches, one patch per changeset.
3018*52f52c14Swdenk
3019*52f52c14Swdenk
3020c609719bSwdenkNotes:
3021c609719bSwdenk
3022c609719bSwdenk* Before sending the patch, run the MAKEALL script on your patched
3023c609719bSwdenk  source tree and make sure that no errors or warnings are reported
3024c609719bSwdenk  for any of the boards.
3025c609719bSwdenk
3026c609719bSwdenk* Keep your modifications to the necessary minimum: A patch
3027c609719bSwdenk  containing several unrelated changes or arbitrary reformats will be
3028c609719bSwdenk  returned with a request to re-formatting / split it.
3029c609719bSwdenk
3030c609719bSwdenk* If you modify existing code, make sure that your new code does not
3031c609719bSwdenk  add to the memory footprint of the code ;-) Small is beautiful!
3032c609719bSwdenk  When adding new features, these should compile conditionally only
3033c609719bSwdenk  (using #ifdef), and the resulting code with the new feature
3034c609719bSwdenk  disabled must not need more memory than the old code without your
3035c609719bSwdenk  modification.
3036