Subject: Re: bacbsd for 040
To: None <finchm@csugrad.cs.vt.edu, kallio@jyu.fi>
From: Chris Caputo <ccaputo@microsoft.com>
List: macbsd-general
Date: 11/17/1993 14:12:48
>This question is definately a FAQ.  We do not use the code in the ROMs.
>Apple's lawyers had nothing to do with this, its because we did not want
>to go insane playing with Apple's ROMs.  If people want to try writing
>device drivers that use the ROMS-- they are more than welcome.  I
>believe that the only ROM routine we call is shutdown ( Is this correct?
>Chris, how long did you trace with macsbug to find the entry point to
>this code? )  Another reason we do our own drivers, is that we can do a
>better job than Apple, something we haven't quite done yet.  Our SCSI
>when it finally works will support disconnect-reconnect, Apple can't do
>that.  When our Serial finally works, we won't lose chars when the
>system beeps (A/UX does).  Etc.

Plus, there are many bugs in the roms that are fixed by MacOS when it
is loaded.  We can't use these fixes, because we would have to infringe
Apple copyrights to do so.

Finding the shutdown routine took under an hour.  The really frustrating
thing is that I never figured out why I had to call it, rather than just
copying the code and executing it myself.  Having to hard code the
shutdown entry-point most likely means that shutdowns won't work on
non-MacII style machines (ie. different roms).

As far as why it wouldn't work when I copied it (it was only a few lines,
not a major copyright violation :-) I suppose maybe the hardware vector
depended on the shutdown being executed from a certain rom location.
Could this be?

Chris

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