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From: jnemeth@cue.bc.ca (John Nemeth)
Subject: Re: Coexisting on the PC
Message-ID: <1994Mar10.090638.1364@softwords.bc.ca>
Sender: news@softwords.bc.ca (CNews)
Nntp-Posting-Host: cue.bc.ca
Organization: Computer Using Educators of B.C., Canada
References: <CLz6un.A9G@rex.uokhsc.edu> <2l3nvj$fpc@u.cc.utah.edu>
Date: Thu, 10 Mar 94 09:06:38 GMT
Lines: 51
In article <2l3nvj$fpc@u.cc.utah.edu> terry@cs.weber.edu (Terry Lambert) writes:
>In article <CLz6un.A9G@rex.uokhsc.edu> benjamin-goldsteen@uokhsc.edu writes:
>[ ... discussion of device naming conventions ... ]
>
>This is argued out on the mailing lists more frequently than I would like,
>so before this is reposted, I thought I'd issue a preeemptive strike.
Hmm... Guess, I'll have to join the mailing lists one of these
days (just what I needed, more mail).
>System V (I know, supposedly dirty word) resolves the naming issues by:
You got that right. :-)
>cAtBdCsD
Yes, I know, and I really don't care for it. I also don't care
for the way admin stuff (including devices) gets splattered all over
the place. I'm quite capable of administrating both BSD and System V,
but I think BSD is a lot nicer and easier to handle.
>Since BSD drivers don't care about geometry, only about absolute sector
>number, this means getting the information is sufficient to allow the
>mounting of DOS partitions as long as the DOS FS mount took the DOS
>parition number s an argument and used the generic "whole disk device"
>without causing it to be marked as mounted. This resolves the issue of
>having to have a disklabel entry that points off the logical parition to
>enable mounting of DOS file systems; it assumes the interpretation of
>the DOS parition table data is by means of the DOS apparent geometry,
>which is either reported each time by way of a vm86() INT 13 AH=8 call,
>or more easily done, by having the information passed to the kernel by
>way of the BIOS boot blocks that can make the call on the kernels behalf
>before entering protected mode.
Apparently, Linux uses wd0i for the whole physical disk and
wd0[j-m] for the BIOS style partitions. I think that this is an
interesting idea that is worth considering. To mount a DOS partition,
you would simply type something like 'mount -t msdos /dev/wd0j /DOS'.
I think the DOS/BIOS geometry should be passed in at boot time.
>The implication is that the DOS information, in being logically seperate,
>can be OS specific and sperated in the processer specific protion of the
>the kernel, specifically in the block I/O subsyetm, which does the
>interpretation of the disk label. Thus DOS partition tables are on all
Yes, definitely. All PC stuff should be removed from the
platform dependent parts of the kernel.
--
John Nemeth jnemeth@cue.bc.ca
System Administrator
Computer Using Educators of B.C. Opinions are my own.