Path: utzoo!utgpu!news-server.csri.toronto.edu!qucdn!leek
Newsgroups: comp.sys.amiga.hardware
Subject: Re: 2.0 in FRANCES
Organization: Queen's University at Kingston
Date: Friday, 7 Sep 1990 13:41:38 EDT
From: <LEEK@QUCDN.QueensU.CA>
Message-ID: <90250.134138LEEK@QUCDN.BITNET>
References: <444299@neabbs.UUCP> <153.26e68f95@intersil.uucp>

In article <153.26e68f95@intersil.uucp>, hamilton@intersil.uucp says:
>
>I _think_ that was my mistake.  I now believe it was locking up because
>when you reset the Amiga it wants to yank KS down to location $000000 and
>it probably does other funky stuff that I don't know about during reset.
>
>** If anyone can tell me what an A1000 does during reset I'd appreciate it! **

Reset -> Boot rom is overlayed into 00000000 where 680X0 picks up reset vector
to branch to itself at 00F80000.  It went and decided whether or not kickstart
should be loaded from disk or not.  When that is done, it write protect WCS &
make itself go away, and then branch to Kickstart (with the help of 680x0
prefetch pipeline)

Now there are 2 problems you'll see if you hardwire the remap logic of Frances.
At reset, boot rom kicks in at 00000000, 68000 got branched to boot rom

JMP $F8008A.L    (location which is now occupied by kickstart)

Since the proper address to jump to in 1.2 or 1.3 is FC0002, your Amiga
suffer a freeze-up.  (F8008A might be different for a different version of
boot rom
                                               (F8008A)
Things to try is to place a Jmp FC0002 at that location.  In 1.2/1.3 that
location is occupied by C= copyright notice.  You should be able to edit that
in without problem.  (Remember to calculate a new checksum foir kickstart !!)
Hardwire the Remap logic and you should be able to reboot from 32-bit kickstart
.

If that works, you might want to sit back and work on the Data Cache problem
with Frances...  Right now Derek Noonburg and I are working on a new boot rom
which is relocated to F00000.  If that works, it would branch to the proper
address for 1.X or 2.X kickstarts.  Other solutions exists too.

>--
>Fred Hamilton                  Any views, comments, or ideas expressed here
>Harris Semiconductor           are entirely my own.  Even good ones.
>Santa Clara, CA

Send me email if you want more boot rom info...  (I had problem reaching you.)

K. C. Lee
Elec. Eng. Grad. Student