Subject: Re: Mac m68k booting process?
To: Allen Briggs <email@example.com>
From: Michael R. Zucca <firstname.lastname@example.org>
Date: 09/05/2000 23:36:11
At 11:58 AM -0400 9/5/00, Allen Briggs wrote:
>As someone else noted, we don't have full MacOS services at this point
>in the boot and can't, for example, turn off video interrupts on nubus
>cards reliably (or as reliably as we can once things are booted). This
>is true, but we do already know how to clear nubus interrupts on quite
>a few video cards (even if we don't know anything else about them ;-).
Not turning off video interrupts is OK, though. Only PrimaryInit has been
run and cards are *supposed* to initialize and then come into a quiessant
(sp?) state at that point. If cards didn't at least shut up long enough for
MacOS to boot, they would never have worked at all. The card isn't supposed
to "start up" until SecondaryInit, which is basically when the System has
loaded and is running.
A stand-alone booter that intercepts at the boot-block level should work
OK. It should probably work even better than out of Mac/OS because all the
harware should actually be quiet when we boot. :-)
As others have pointed out, though, we would need to do a little more than
we do now because alot of initialization is done during SecondaryInit. Most
of our services should be OK: SCSI, ethernet, ADB, etc. Other stuff is
probably broken, though. I would imagine that the IOP code in the IIfx ROM
sucks enough that we'd have to roll our own, though.
> (Michael Zucca has been working on this for
>four years or so--maybe it's close to being ready for prime time? ;-),
>better interrupt scheduling, etc...
Oh man. I am *so* ashamed. I mean it! I have such a bad case of real-life,
it's not funny. I'm lucky I have time to read the mailing list anymore. If
somebody wants to work on video, I can share info. Now that the fb
interface is in, doing drivers for CLUT loading should be a piece of cake.
Changing modes is a little more work on machines like the II series.
Quadras need more work, though. I never got around to gathering the timing
data from those machines. Damn! I wish I had more time to work on this
Michael Zucca - email@example.com - http://www.mdc.net/~mrz5149/
"I will choose a path that's clear. I will choose Freewill. "