From owner-freebsd-hackers Mon Apr 3 13:27:58 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id NAA18407 for hackers-outgoing; Mon, 3 Apr 1995 13:27:58 -0700 Received: from irz301.inf.tu-dresden.de (irz301.inf.tu-dresden.de [141.76.1.11]) by freefall.cdrom.com (8.6.10/8.6.6) with SMTP id NAA18369 for ; Mon, 3 Apr 1995 13:27:43 -0700 Received: from sax.sax.de by irz301.inf.tu-dresden.de with SMTP (5.67b+/DEC-Ultrix/4.3) id AA13642; Mon, 3 Apr 1995 22:23:34 +0200 Received: by sax.sax.de (8.6.9/8.6.9-s1) with UUCP id WAA22956 for freebsd-hackers@freebsd.org; Mon, 3 Apr 1995 22:23:33 +0200 Received: (from j@localhost) by uriah.heep.sax.de (8.6.11/8.6.9) id WAA00745 for freebsd-hackers@freebsd.org; Mon, 3 Apr 1995 22:12:37 +0200 From: J Wunsch Message-Id: <199504032012.WAA00745@uriah.heep.sax.de> Subject: Re: grafx console & DDB To: freebsd-hackers@FreeBSD.org (FreeBSD hackers) Date: Mon, 3 Apr 1995 22:12:36 +0200 (MET DST) In-Reply-To: <9504031838.AA07543@cs.weber.edu> from "Terry Lambert" at Apr 3, 95 12:38:15 pm Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) X-Phone: +49-351-2012 669 X-Mailer: ELM [version 2.4 PL23] Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Content-Length: 1240 Sender: hackers-owner@FreeBSD.org Precedence: bulk As Terry Lambert wrote: > > > Before Terry jumps in: i know that this is not the generic solution. > > The console drivers should reinitialize the system's console via a > > vm86() call to the video BIOS -- but i don't see this solution around > > the corner within the next weeks. > > Too late. ;-). > > No, the generic soloution is to not allow the X server direct access > to the mode registers, and instead force it to go through a kernel > driver. Of course, but it's even harder to make than the vm86() story. In case of a panic(), almost everything it's lost, so i don't really care if the X server shuts down nicely. > Making VM86() calls in the BIOS is a way to set video modes on > otherwise undocumented hardware... but it is *dangerous*. Most > "modern" video cards ..., and they will disable > *all* interrupts while in an INT 10 call rather than looking slow > on benchmarks and waiting for the vertical blanking interval to > do their jobs. ... I didn't think of that. Perhaps vm86() should always run non- privileged (except of the IOPL), and the GP fault being ignored? -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ Never trust an operating system you don't have sources for. ;-)