Date: Mon, 01 Apr 2002 15:05:02 -0800 From: Terry Lambert <tlambert2@mindspring.com> To: Michael Smith <msmith@freebsd.org> Cc: Dmitry Konyshev <daemon@agava.com>, freebsd-hackers@FreeBSD.ORG Subject: Re: finding out boot device Message-ID: <3CA8E79E.51DF359D@mindspring.com> References: <200204011857.g31Iv0g01534@mass.dis.org>
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Michael Smith wrote: > > One way to obtain this information is to write a program > > that uses vm86() calls to read the first N sectors of a > > BIOS disk, then read the same area using the protected mode > > drivers. When you get a unique MD5 hash match between the > > BIOS and the boot device, you're there. > > This won't work, since we'll have spammed the device state by then. > You'd have to compute the fingerprints in the loader before booting. Yep. It's worse than that, because it means identical disks need to be differentiated some other way, besides just upping the MD5 region until it covers the whole disks (e.g. writing to them). This is how Windows converts open file handles in TSRs into VFAT32 file handles, BTW. Of course, now everyone knows where it was invented, it will be an unacceptable approach... ;^). -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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