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- /*
- * (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.
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