u-boot/board/fads
Albert ARIBAUD ef123c5253 Refactor linker-generated arrays
Refactor linker-generated array code so that symbols
which were previously linker-generated are now compiler-
generated. This causes relocation records of type
R_ARM_ABS32 to become R_ARM_RELATIVE, which makes
code which uses LGA able to run before relocation as
well as after.

Note: this affects more than ARM targets, as linker-
lists span possibly all target architectures, notably
PowerPC.

Conflicts:
	arch/arm/cpu/arm926ejs/mxs/u-boot-spl.lds
	arch/arm/cpu/arm926ejs/spear/u-boot-spl.lds
	arch/arm/cpu/armv7/omap-common/u-boot-spl.lds
	board/ait/cam_enc_4xx/u-boot-spl.lds
	board/davinci/da8xxevm/u-boot-spl-da850evm.lds
	board/davinci/da8xxevm/u-boot-spl-hawk.lds
	board/vpac270/u-boot-spl.lds

Signed-off-by: Albert ARIBAUD <albert.u.boot@aribaud.net>
2013-03-12 23:28:40 +01:00
..
fads.c board/fads/fads.c: Fix GCC 4.6 build warning 2011-11-07 22:15:22 +01:00
fads.h hush.c: Move default CONFIG_SYS_PROMPT_HUSH_PS2 to hush.c 2012-06-20 20:36:51 +02:00
flash.c rename CFG_ macros to CONFIG_SYS 2008-10-18 21:54:03 +02:00
lamp.c * Patch by Yuli Barcohen, 3 Dec 2003: 2003-12-07 21:39:28 +00:00
Makefile Switch from archive libraries to partial linking 2010-11-17 21:02:18 +01:00
pcmcia.c Big white-space cleanup. 2008-05-21 00:14:08 +02:00
README doc: cleanup - move board READMEs into respective board directories 2012-07-29 15:42:02 +02:00
u-boot.lds Refactor linker-generated arrays 2013-03-12 23:28:40 +01:00

/*
 * (C) Copyright 2000
 * Dave Ellis, SIXNET, dge@sixnetio.com
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

Using the Motorola MPC8XXFADS development board
===============================================

CONFIGURATIONS
--------------

There are ready-to-use default configurations available for the
FADS823, FADS850SAR and FADS860T. The FADS860T configuration also
works for the 855T processor.

LOADING U-Boot INTO FADS FLASH MEMORY
--------------------------------------

MPC8BUG can load U-Boot into the FLASH memory using LOADF.

    loadf u-boot.srec 100000


STARTING U-Boot FROM MPC8BUG
-----------------------------

To start U-Boot from MPC8BUG:

1. Reset the board:
    reset :h

2. Change BR0 and OR0 back to their values at reset:
    rms memc br0 00000001
    rms memc or0 00000d34

3. Modify DER so MPC8BUG gets control only when it should:
    rms der 2002000f

4. Start as if from reset:
    go 100

This is NOT exactly the same as starting U-Boot without
MPC8BUG. MPC8BUG turns off the watchdog as part of the hard reset.
After it does the reset it writes SYPCR (to disable the watchdog)
and sets BR0 and OR0 to map the FLASH at 0x02800000 (and does lots
of other initialization). That is why it is necessary to set BR0
and OR0 to map the FLASH everywhere. U-Boot can't turn on the
watchdog after that, since MPC8BUG has used the only chance to write
to SYPCR.

Here is a bizarre sequence of MPC8BUG and U-Boot commands that lets
U-Boot write to SYPCR. It works with MPC8BUG 1.5 and an 855T
processor (your mileage may vary). It is probably better (and a lot
easier) just to accept having the watchdog disabled when the debug
cable is connected.

in MPC8BUG:
  reset :h
  rms memc br0 00000001
  rms memc or0 00000d34
  rms der 2000f
  go 100

Now U-Boot is running with the MPC8BUG value for SYPCR. Use the
U-Boot 'reset' command to reset the board.
  =>reset
Next, in MPC8BUG:
  rms der 2000f
  go

Now U-Boot is running with the U-Boot value for SYPCR.