Subject: Re: More than just the compiler, the FS tools ...
To: David Brownlee <>
From: Bill Studenmund <>
List: tech-toolchain
Date: 02/07/1997 09:48:20
On Fri, 7 Feb 1997, David Brownlee wrote:

> On Fri, 7 Feb 1997, Andrew Cagney wrote:
> > In the longer term, however, I suggest that it would be a good strategy
> > to steer the FS tools in a direction that allowed them to be built and
> > used on foreign hosts.
> > 
> 	Most certainly - 'disklabel' currently has code that installs
> 	bootblocks on some (i396) architectures. I think this has been
> 	described as 'just plain wrong'.
> 	The first stage that needs to be done is splitting out the
> 	disklabel handling code from the ports - so I can for example
> 	mount a SunOS disk on a NetBSD/i386 machine. Before that
> 	happens we need to cope with big/little endian ffs on a given
> 	machine.

I've been thinking about this probelem. It shouldn't be TOO hard, though
tedious. My thought was to add partition types of BE_FFS and LE_FFS (sp?),
and to leave FFS as-is. Also, teach disklabel about different disklabel
types, like big-E NetBSD, little-E NetBSD, sun, DOS, cd9660, amiga, atari,

The idea is to have stub routines which can read (and write) each
partition scheme. The stubs would also use BE_FFS & LE_FFS if the
disklabel's made dynamically (from the other OS's scheme), or if the
disklabel nativly was for a different byte order (like you take a Big-E
sun disklabel (w/ FFS's in it) and hook it to an i386).

The thought for BE_FFS and LE_FFS is to pepper the ufs code w/ wrappere
where ever on-disk entities are touched. To make the native-endian fs,
these wrappers are null (#define wrapper(x)  (x)).

> 	Actually, from my viewpoint just being about to mount a DOS
> 	formatted Jaz disk on my NetBSD/sparc box would be real nice, but
> 	I'm upgrading to current in preparation for poking around at that
> 	:)

The other (cool but essoteric) thing it can do is you could tell disklabel
to look for a certain type of disk label. Zip Tools disks have both DOS
and MacOS partitions on them, and this way we could read them (and
possably write them too!).

Take care,