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diff --git a/board/fads/README b/board/fads/README new file mode 100644 index 0000000..bae9652 --- /dev/null +++ b/board/fads/README @@ -0,0 +1,89 @@ +/* + * (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. |