From owner-freebsd-arch@FreeBSD.ORG Sun Oct 30 16:45:22 2005 Return-Path: X-Original-To: freebsd-arch@freebsd.org Delivered-To: freebsd-arch@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7FD1D16A41F for ; Sun, 30 Oct 2005 16:45:22 +0000 (GMT) (envelope-from babkin@verizon.net) Received: from vms044pub.verizon.net (vms044pub.verizon.net [206.46.252.44]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3220D43D46 for ; Sun, 30 Oct 2005 16:45:22 +0000 (GMT) (envelope-from babkin@verizon.net) Received: from verizon.net ([138.89.161.30]) by vms044.mailsrvcs.net (Sun Java System Messaging Server 6.2-4.02 (built Sep 9 2005)) with ESMTPA id <0IP6002M8MJECXA5@vms044.mailsrvcs.net> for freebsd-arch@freebsd.org; Sun, 30 Oct 2005 10:45:18 -0600 (CST) Date: Sun, 30 Oct 2005 11:45:14 -0500 From: Sergey Babkin Sender: root To: Kris Kennaway Message-id: <4364F89A.29B607B4@verizon.net> MIME-version: 1.0 X-Mailer: Mozilla 4.7 [en] (X11; U; FreeBSD 4.7-RELEASE i386) Content-type: text/plain; charset=koi8-r Content-transfer-encoding: 7bit X-Accept-Language: en, ru References: <12768156.1130520253107.JavaMail.root@vms073.mailsrvcs.net> <200510281435.41700.jhb@freebsd.org> <4362B611.B4A12AF8@verizon.net> <20051028.215049.102576958.imp@bsdimp.com> <20051030104814.GA32477@xor.obsecurity.org> Cc: gbergling@0xfce3.net, babkin@users.sourceforge.net, phk@phk.freebsd.dk, freebsd-arch@freebsd.org Subject: Re: wscons for FreeBSD? X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: babkin@users.sf.net List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Oct 2005 16:45:22 -0000 Kris Kennaway wrote: > > On Fri, Oct 28, 2005 at 09:50:49PM -0600, M. Warner Losh wrote: > > In message: <4362B611.B4A12AF8@verizon.net> > > Sergey Babkin writes: > > : John Baldwin wrote: > > : > > > : > On Friday 28 October 2005 01:24 pm, Sergey Babkin wrote: > > : > > >From: John Baldwin > > : > > > > > : > > : > > * When entering panic/debugger mode the console > > : > > should reset its video mode to the one where > > : > > the panic information is visible. > > : > > > : > I think this might be kind of hard since you really don't know what X has done > > : > to the hardware unless you make X talk to the console driver to do > > : > everything. > > : > > : Can you re-initialize the device from scratch? My knowledge > > : about the video hardware dates to SVGA times and even that > > : is not too deep. > > : > > : Maybe provide a basic SVGA re-initialization routine on x86 and have > > : an interface for the third-party in-kernel drivers that > > : would contain the re-initialization routine. > > > > When this has come up in the past, those in the know say that it takes > > card specific registers and knowledge to reset these cards' video > > modes. > > Even if it doesn't work on all cards, if there's some method that will > at least work for a subset of configurations it may be worth > investigating: by that point the machine has panicked anyway, so > what's the worst that can happen? I think that if there are no endless busy waits, nothing should make the situation any worse. I guess for VESA-compatible cards the VESA BIOS couls be used too, but that's much more complicated to do and much more prone to things going wrong during resets. But I guess in any case providing an interface for the in-kernel reset drivers would solve the problem as long as there are those drivers. Their implementation can probably be extracted from XF86, though of course it would need extra work. -SB