Date: Thu, 4 Jan 1996 13:43:14 +1030 (CST) From: Michael Smith <msmith@atrad.adelaide.edu.au> To: terry@lambert.org (Terry Lambert) Cc: msmith@atrad.adelaide.edu.au, terry@lambert.org, jdl@jdl.com, jkh@time.cdrom.com, obrien@cs.ucdavis.edu, freebsd-hackers@freebsd.org Subject: Re: X for install Message-ID: <199601040313.NAA09827@genesis.atrad.adelaide.edu.au> In-Reply-To: <199601040159.SAA16479@phaeton.artisoft.com> from "Terry Lambert" at Jan 3, 96 06:59:46 pm
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Terry Lambert stands accused of saying: > > Ok Terry, you win. VM86() it is; now can you or one of the other VM > > wizards dribble enough of it out so that we can set up a context in > > which it is safe to make BIOS calls? > > Well, this didn't *necessarily* need a VM86(). But that *is* one > soloution... I was thinking on the lines of a weenie DOS program > to blow the 32 bit offsets in the partition table before install. We need an awful lot more than that. While probing for disks and other devices, we need a BIOS disk driver that can read the root filesystem and suck in LKMs, including the disk drivers. Eventually, / would be remounted from another device, and the now-loaded 'real' disk drivers would come into play if they could, or the BIOS fallback driver would continue to carry the load. > the ideal candidate. 8-) 8-). I have someone else who I'd nominate, > since he has been all over the Win95 VM system very recently, but he'd > probably kill me for it... You could do with a good killing, so I suggest you nominate away. 8) > They had a VM86() mode working well enough for DOSEMU. This is not > quite enough for a "call this BIOS call on my behalf in a Virtual 8086 > machine that prevents kernel reentrancy, please". Which is really what > needs to be done, unless you dick with the DOS stack for the low INT > calls (there's a nice TSR book that describes doing exactly this with > Borland Turbo C). I'm not going to try to define "what needs to be done" at that level; I'm suggesting that you & several other people know what needs to be done, and I'm just prodding at you until you do it. Hint? 8) > Actually, you *don't* want video BIOS for anything more than mode > setting. Most VGA cards that emulate EGA and CGA registers (Paradise, > etc.) disable interrrupts instead of waiting for the vertical blank > interrupt to handle screen draws. A no-no if you have active serial > ports or a network card, floppy tape, etc. Point. Video hardware is sufficiently standard that BIOS support's not a great win except maybe for VESA BIOS operations, and they're not terribly standard. > Terry Lambert -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] "Who does BSD?" "We do Chucky, we do." [[
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