Date: Wed, 14 Oct 1998 01:14:50 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: mike@smith.net.au (Mike Smith) Cc: karpen@ocean.campus.luth.se, hackers@FreeBSD.ORG Subject: Re: BETA problems... Message-ID: <199810140114.SAA21361@usr08.primenet.com> In-Reply-To: <199810130120.SAA01157@dingo.cdrom.com> from "Mike Smith" at Oct 12, 98 06:20:39 pm
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> > _Is_ it fixed in new boot code, perhaps? > > No. It's almost impossible to get the distinction right. > > The difficulty lies in working out which physical drives the BIOS > numbers correspond to. Unless you have a *very* new system, there is > simply no way to know that the BIOS drive 0x81 is in fact wd2. In > order for this to work, the user has to provide the missing data, > either by typing 1:wd(2a)kernel every time (tedious) or putting it in > /boot.config. Actually, you could MD5 the first N sectors of the disk using both VM86() I/O and kernel I/O, and if the MD5 matched, you've found your drive. If you have two drives that MD5 the same, tweak an unused portion of one of them using VM86() I/O and see which one got tweaked using kernel I/O, and, again, you've found your drive. It's *not* impossible, since this is how Windows 95/98 converts fd's opened using the INT 21 based I/O in AUTOEXEC.BAT to fd's that, when INT 21 I/O is done to them in protected mode (via thunk) into calls to the protected mode disk drivers and IFS layer (VFAT, VFAT32, etc.) instead. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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