amd64/111955: [install] Install CD boot panic due to missing
BIOS smap on 5.5 through to 7.0-Current Snapshot 200704
jhb at FreeBSD.org
Mon Feb 11 12:50:03 PST 2008
The following reply was made to PR amd64/111955; it has been noted by GNATS.
From: John Baldwin <jhb at freebsd.org>
To: bug-followup at freebsd.org, Roque at itg.uni-muenchen.de
Subject: Re: amd64/111955: [install] Install CD boot panic due to missing BIOS smap on 5.5 through to 7.0-Current Snapshot 200704
Date: Mon, 11 Feb 2008 15:46:04 -0500
So the SMAP problem is that in the one BIOS I looked at, the SMAP BIOS call
only works from real mode. Even if invoked from virtual 86 mode, the BIOS
call fails. FreeBSD only calls the BIOS SMAP call from virtual 86 mode both
in the loader and in the i386 kernel. The fix is quite complicated and
involves rewriting the boot code to invoke BIOS calls from real mode rather
than virtual 86 mode.
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