by homeworld.cygnus.com with SMTP; 25 Jan 1997 04:31:32 -0000
Date: Fri, 24 Jan 1997 23:27:57 -0500 (EST)
Message-Id: <199701250427.XAA17073@dynamo.cs.columbia.edu>
From: Jonathan Lennox <lennox@cs.columbia.edu>
To: port-mac68k@netbsd.org
Subject: Help understanding VIA interrupts?

  I've recently returned to my attempts to get the Mac ROM Glue working on
the Quadra 950's IOPs, and I think I've finally figured things out -- except
I don't understand enough about the VIA interrupts, and MacBSD's use of
them, to have the IOP interrupts be seen and have the ROM interrupt routine
be called.

  From my examination of MacOS, on the 950 the IOP Interrupt looks to be
interrupt 0 on VIA2.  Can anyone tell me what I should do to enable that
interrupt, and have it call my handler when one is received?

  (My first impression would just be to put a pointer to the handler in
via2itab[0] in via.c -- but if that were all it was, I would presumably be
seeing via2_noint's debug messages when the interrupts come in, no?  So I
think I need to enable the interrupt someplace -- and the question is where
and how.)

  Thanks in advance for any help...

-- 
Jonathan Lennox
lennox@cs.columbia.edu