Subject: Re: The Horror ROM (not configured)
To: John D. Smerdon <jds@smerdon.livonia.mi.us>
From: Allen Briggs <briggs@puma.macbsd.com>
List: port-mac68k
Date: 06/08/1996 21:39:27
> Finding valid nubus info at the end of Centris 650 ROM as Allen suggested,
> I configured a kernel that would attempt to use it.

I have been thinking about how we can use this kind of information.  I
think we need it in order to support Duo Docks as well.

> nubus0: slot f: Unknown Macintosh (Vendor: Apple Computer, Inc., Part: The
> Horror ROM)  not configured

Those Apple guys must have had fun...  I'd like to see what they named
the AV ROMs...  :-)

> I was hoping that it would find the internal video.

We need some more code in there to pull out the proper drivers, etc.
The problem is that the system and Duo Dock ROMs (and some other devices
out there) are multi-function devices in the sense that the declaration
ROM describes many different devices (actually, most video cards have
several entries, too).  The problem is that the card's initialization
code often removes the non-existant devices from the ROM's listing--hence
the two options in 'Slots': "Use Config ROM/Use Slot Mgr".
I think we've got two choices:

	* Load the card's initialization routine and run it with an
	  emulated slot manager.

	* Load the values from the slot manager in the booter and then
	  use those values at device probe time.

The former may get us into trouble if the init routines want a lot of
the MacOS to be there.  We're already starting to emulate the basic
functions, though, and it might not be unreasonable to work from this
angle.  Loading the values in the booter is certainly easier, but every
little bit that we add to the booter makes booting from a boot block
that much harder.

-allen

-- 
 Allen Briggs - end killing - briggs@macbsd.com ** MacBSD == NetBSD/mac68k **
   Where does all my time go?  <a href="http://www.netbsd.org/">Guess.</a>