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Path: sserve!newshost.anu.edu.au!harbinger.cc.monash.edu.au!bunyip.cc.uq.oz.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!usc!howland.reston.ans.net!europa.eng.gtefsd.com!MathWorks.Com!yeshua.marcam.com!charnel.ecst.csuchico.edu!xmission!u.cc.utah.edu!cs.weber.edu!terry From: terry@cs.weber.edu (Terry Lambert) Newsgroups: comp.os.386bsd.development Subject: Re: FreeBSD 2.0: someone please fix mount_pcfs Date: 19 Aug 1994 04:07:27 GMT Organization: Weber State University, Ogden, UT Lines: 42 Message-ID: <331b5v$q00@u.cc.utah.edu> References: <32uvui$dov@Venus.mcs.com> NNTP-Posting-Host: cs.weber.edu In article <32uvui$dov@Venus.mcs.com> mikebo@MCS.COM (Michael Borowiec) writes: ] It would be nice if mount_pcfs would mount a DOS partition from a ] DOS only hard disk (one without a UNIX disk label). I have two SCSI ] drives, one exclusively FreeBSD and the other exclusively DOS. ] Depending on which OS I want to run, I simply swap SCSI ID 0 and 1 ] and re-boot. Having used a boot manager for quite some time, and ] having trashed and re-built my DOS partition more times than I care ] to remember, IMHO this is a much better solution. I just discussed the precise changes that would be neccessary to do this in an article in comp.unix.bsd, less than 24 hours ago (I think). ] I have used many PC UNICES (Interactive, SCO, UnixWare, BSD386) and ] I believe FreeBSD is the only one of these that can't mount a DOS ] partition from a DOS only hard drive (again, without a UNIX disk label). ] 'Cuz I am not a filesystem hacker (by any stretch) perhaps I am naive, ] but I can't believe this would be that hard to do. UnixWare, NetBSD, FreeBSD are *known* to require a partition of the particular OS type to allow mounting. UnixWare, by default, as a matter of record, doesn't have the ability to mount DOS file systems without the FSK (Filesystem Survival Kit) code, which is *BSD derived. I suspect Linux and others also have this limiation, it's just that I haven't checked them out for it one way or another to be able to say. The reasoning is that the DOS partition table, which you would have to read to do the mount, barring a partition with a disklabel (or in the UnixWare case, a Volume Table Of Contents), there is no way to decode the C/H/S values as absolute sector offsets without a firm grasp of the BIOS apparent geometry on a translated (ie: modern) disk drive. I suspect SCO will fail this test on modern drives. The posting I made is how to tell the kernel the BIOS apparent geometry without a disklabel. Terry Lambert terry@cs.weber.edu --- Any opinions in this posting are my own and not those of my present or previous employers.