Re: IOPanic ans assert not working ?
Re: IOPanic ans assert not working ?
- Subject: Re: IOPanic ans assert not working ?
- From: "David A. Gatwood" <email@hidden>
- Date: Tue, 5 Feb 2002 16:54:51 -0800 (PST)
On Tue, 5 Feb 2002, Andrew Gallatin wrote:
>
Given the author is from matrox.com, it is possible he's working on a
>
video driver...
>
>
What does OS X do if the video driver is hosed? Does it switch to
>
using Open Firmware for I/O at panic time? Or does it call back into
>
the possibly hosed video driver which may no longer be able to write
>
things onto the framebuffer?
You can't use OF for video by the time the Mac OS X kernel starts. The
mach console is legacy MkLinux code that still manages to scratch its way
to the surface every so often. ;-)
Panic messages, AFAICT, take a different path through video_console.c than
other text, and I would hope that they don't do any callbacks to the video
driver. If it did, you could get something like:
1. Driver init routine panics
2. Mach starts panic display.
3. Oh, driver isn't initted. Call init routine.
4. Go to step 1.
Which is a bad thing. I don't see any call-backs, though, so I kind of
doubt that's what's happening. At least I hope not. :-)
Later,
David
---------------------------------------------------------------------
Check out my weekly web comic:
http://www.techmagazine.org