Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!udel!rochester!kodak!ispd-newsserver!ism.isc.com!ico!rcd
From: rcd@ico.isc.com (Dick Dunn)
Newsgroups: comp.unix.sysv386
Subject: moving the fp regs
Summary: not *that* hard
Message-ID: <1991Feb22.225135.12692@ico.isc.com>
Date: 22 Feb 91 22:51:35 GMT
References: <7667@crash.cts.com> <1991Feb21.141349.26015@virtech.uucp> <1991Feb21.193529.15339@kithrup.COM>
Organization: Interactive Systems Corporation, Boulder, CO
Lines: 23

sef@kithrup.COM (Sean Eric Fagan) writes:
> cpcahil@virtech.uucp (Conor P. Cahill) writes:
> >This kind of change will require a recompile of every module that accesses
> >the user structure plus some additional changes ...
...
> Which happens to include just about every device driver, and *does* include
> things like NFS...
> ...I, personally, am interested to
> see if they are going to do it in a compatable manner...

C'mon, Sean, you're more imaginative than that!  You just leave a hole
where you move the FP regs out (leave a dummy of the structure there)
and adjust sizes where you put them in.  Check it carefully, and the
offsets to the stuff used by drivers can remain the same.

(I'm *not* the one doing the change.  This is just a general observation
based on what needs to happen.  The hard part is NOT the principle of
keeping essential parts of the u-area compatible; it's the many practical
matters involved in ensuring that you don't screw up something else in the
process.)
-- 
Dick Dunn     rcd@ico.isc.com -or- ico!rcd       Boulder, CO   (303)449-2870
   ...But is it art?