Date: Tue, 24 Feb 1998 13:25:29 -0800 From: Mike Smith <mike@smith.net.au> To: shimon@simon-shapiro.org Cc: =?us-ascii?Q?S=F8ren?= Schmidt <sos@FreeBSD.ORG>, freebsd-current@FreeBSD.ORG, yokota@zodiac.mech.utsunomiya-u.ac.jp, abial@nask.pl (Andrzej Bialecki) Subject: Re: Proposed addition to panic() behaviour Message-ID: <199802242125.NAA16540@dingo.cdrom.com> In-Reply-To: Your message of "Tue, 24 Feb 1998 11:50:09 PST." <XFMail.980224115009.shimon@simon-shapiro.org>
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> > On 24-Feb-98 Søren Schmidt wrote: > > .... > > > It will only work on a std VGA card in a std mode. All moderne video > > cards > > demands specific programming (or what do you think the thousands of lines > > of code in Xfree86 does :) ) > > > > So your answer is it will not work most of the time, if at all. > > My ignorance shows all the time. When the system boots, something does > something to the video card to make it go into a sane VGA mode. My > ignorant assumption is that this something can be emulated/repeated with > software in kernel mode. That something is card-specific code in the BIOS ROM on the card. You may see it signing on if your monitor warms up quickly enough. This is real-mode 8086 code which can make all sorts of assumptions about the state of the machine at that point in the boot phase. Some of those assumptions aren't valid when the kernel is running. (Some are, but to get to a mode where you can run this code is a bit daunting.) -- \\ Sometimes you're ahead, \\ Mike Smith \\ sometimes you're behind. \\ mike@smith.net.au \\ The race is long, and in the \\ msmith@freebsd.org \\ end it's only with yourself. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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