[comp.sys.atari.st] Supervisor Mode query

dcripe@ccvaxa.UUCP (12/08/87)

I'm currently investigating the possibility of porting the Xinu (Xinu Is Not
Unix) operating system (Comer, Operating System Design: The Xinu Approach,
Prentice-Hall) to the Atari ST.

What I have: Atari ST 1040, and Lattice C (no assembler) compiler.

What I need: Information reguarding the "swap timer interrupt vector" call.

When the interrupt occurs, does the installed interrupt service routine get
executed in Supervisor mode?  From what I have read of the 68000 I believe that
this is probably the case (I can find out, but I'd actually have to write a test
program, and you know how lazy us CS types can get).  I need to get control
away from the kernel so the new operating system can take over certain tasks.

If there's an easier way to get into supervisor mode I'd like that information,
too.

I would like to be able to design the system so that each process can access
both Gem and Xinu facilities without interference.  This is probably going to be
painfully difficult, and I'm working on it in my spare time (very little of it
I might add), so don't expect anything spectacular soon.

Responses might not be of interest to the general readership, so you better
reply to me directly.  If I don't hear from you in a few days, forget it: I'll
write the darn test program and find out for myself.

				Thanks in advance,
				Dan Cripe

Disclamer: Since I've no opinions to express, I doubt that anyone cares if I
	   disclaim them or not.  But to satisfy those of you who hunger for
	   such statments, "My employer does not necessarily agree with any
	   opinions expressed or implied, nor does my employer support any
	   statments of alleged fact."

	   Dan Cripe, Gould CSD, Urbana, IL