From 86dc490ac4c21946a47ffdddedb8b494929bfb2c Mon Sep 17 00:00:00 2001 From: Joel Sherrill Date: Mon, 5 Oct 1998 18:21:11 +0000 Subject: Update from Thomas Doerfler . --- c/src/lib/libbsp/powerpc/helas403/README | 58 ++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) (limited to 'c/src/lib') diff --git a/c/src/lib/libbsp/powerpc/helas403/README b/c/src/lib/libbsp/powerpc/helas403/README index 0962302968..38523385b4 100644 --- a/c/src/lib/libbsp/powerpc/helas403/README +++ b/c/src/lib/libbsp/powerpc/helas403/README @@ -43,6 +43,64 @@ STOP BITS: 1 Notes ===== +Board description +----------------- +clock rate: 25 MHz +bus width: 8-bit PROM, 32-bit DRAM +ROM: Up to 512KByte (Am29F040), 90 nsec chip select 0 +RAM: 4 to 32 MByte DRAM SIMM (autodetect), 70 nsec, + no parity, at CS7 or CS6+CS7 (for two-bank-SIMMs) + + helas403 only supports single processor operations. +Porting +------- +This board support package is written for a typical PPC403GA +system. The rough features of this board are described above. + +This BSP contains files for two startup methods: +- Direct start from Flash after powerup (with code run out of flash): + This is the default configuration, it uses the files + flashentry/flashentry.s + startup/linkcmds + + Please note, that this configuration is good to startup the system, +but it will not gain maximum performance due to slow Flash access (8 +bit wide only) + +- Start after software download into DRAM: + This configuration will use: + dlentry/dlentry.s + startup/linkcmds.dl + +If you want to use the download configuration, it is sufficient to +rename the file "startup/linkcmds.dl" to "startup/linkcmds", it will +automatically reference the dlentry.s as entry code. (Renaming is not +quite elegant, a more sophisticated solution will follow in future, +any hints welcome ;-) + +For adapting this BSP to other boards, the following files should be +modified: + +- c/src/lib/libbsp/powerpc/helas403/flashentry/flashentry.s + for the memory controller configuration and other basic stuff + +- c/src/lib/libbsp/powerpc/helas403/startup/linkcmds[.dl] + for the memory layout required + +- c/src/lib/libbsp/powerpc/helas403/startup/bspstart.c + for adaption of BSP_Configuration. here you can select + the clock source for the timers and the serial interface + (system clock or external clock pin), the clock rates, initial + baud rate and other stuff + +- c/src/lib/libbsp/powerpc/helas403/include/bsp.h + some BSP-related constants + +The actual drivers are placed in +- c/src/lib/libcpu/powerpc/ppc403/* + well, they should be generic, so there _should_ be no reason + to mess around there (but who knows...) + -- cgit v1.2.3