Allen Briggs <briggs@ninthwonder.com> wrote:

Allen> They'll break on systems that don't have a Daystar
Allen> installed.  Scott might have other ideas, but I see
Allen> basically three approaches:

Yup.  I wondered if there's the way to avoid the breakage.

Allen> [ In any of them, you'll have to probe for a Daystar
Allen> by checking to see if a read to any of the memory
Allen> locations generates a bus error. ]

Is there an easy way to recoover from a bus error which was
caused by Daystar checking?  It occurs in early stage of
kernel boot strap, I don't know what to do here.

Allen> 1) (my favorite) If there is no Daystar, map a single
Allen> page of memory over the 5 pages where the Daystar
Allen> lives, then use the same code everywhere.  It's a
Allen> minor hit on systems that don't have a Daystar, but
Allen> it keeps everything pretty clean.

I'll take it, too.  That would be shared with other
accelerator card.

--
SUNAGAWA Keiki <kei_sun@ba2.so-net.ne.jp>
Hack on NetBSD, and your code runs on over 20 architectures!