Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ulowell!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Help with Supervisor State
Message-ID: <5850@cbmvax.UUCP>
Date: 30 Jan 89 18:19:13 GMT
References: <10510@well.UUCP>
Distribution: comp
Organization: Commodore Technology, West Chester, PA
Lines: 27

in article <10510@well.UUCP>, sjm@well.UUCP (Stephen Moehle) says:
> Keywords: supervisor state

>     Well, since no one saw fit to help me out with using the 68851 on the
> A2620 board, I have been blindly trying to figure it out.  I actually think
> that I can get the 68851 to do what I want, but I cannot even try it.  

Funny, I could never get the SuperState()/UserState() stuff to work, either.
No bother, really, though; I found two other ways to get there.  From C, 
you can run a subroutine as a software interrupt routine (set up the
routine, then Cause() it); interrupts run in Supervisor mode.  That's gonna
get kind of clumsy if you've got lots of supervisor stuff to do.  From
assembly language you can get to an Exec routine called Supervisor.  Basically,
you pass this call your subroutine, the subroutine is executed in Supervisor
mode, and then it exits with an RTE.  I use this method in my SetCPU program,
V1.3 and above.  Speaking of "and above", I'm just about done with a version
of SetCPU that lets you use the MMU for relocation of ROM into 32 bit RAM.
It's not extremely sophisticated, but it's currently working, and I'll probably
be posting it in the next few days.

> Stephe
> {ucbvax,pacbell,hplabs}!well!sjm     or     well!sjm@lll-winken.arpa
> "You heard the weirdo man.  What is truth?"
-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
              Amiga -- It's not just a job, it's an obsession