Re: [MiNT] drive letters (was: Kernal questions)

[Julian Coleman <J.D.Coleman@newcastle.ac.uk>]

Martin-Eric Racine <q-funk@pp.fishpool.com> wrote:
> Last time I checked, fsck effectively does "fsck.ext2 e:" __NOT__ 

> Aren't the hard-disks partitioned at the DOS level???

Andreas Schwab wrote:
> What have partitions to do with DOS?  It's just a means to, err, partition
> the disk space in mutiple, contiguous regions.  That's completely
> independent from whether there is an OS (Linux) or not (DOS).

It seems there is a degree of confusion here - I'd guess related to different
OS's view on partitions.

In the pure PC/DOS world, each partition had it's own drive letter (e.g. A:,
C:, D:).  This is also used in the Atari TOS world.  Disk partitioning
software on i386 machines also has a very DOS-centric view of partitions -
the partition names are the same as the DOS driver letters.  I don't know
if some TOS/GEM partitioning software does the same (it's a long time since
I partitioned a disk using TOS/GEM software).

In the pure unix world, each partition is mapped to a different device
(e.g. sd0a, sd0b, etc).  The mount program attaches the filesystems on the
devices to different parts of the tree (e.g. /, /usr, /cdrom).  Each
partition on the disk is identified by (e.g.) a different letter or
number (Sun used a-h) which has no relation to the filesystem name.  Unix
systems also treat devices as files, so it is possible access the data
directly (without going through the filesystem), or to mount other than
partitions in the file tree (e.g. regular files containing filesystem
images).

A partition can contain a filesystem image (e.g. FAT16, FFS, EXT2) but
doesn't have to (e.g. a swap partition).

Currently, MiNT seems to be moving away from the TOS/DOS idea toward the
unix idea.  For example, /dev/a and /dev/c are the TOS a: and c: drives
with some versions of MiNT/minixfs/Mintlibs.  Also, the original minixfs
fsck program took the TOS drive letter as a parameter to determine which
partition to work on.

J

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