Subject: Re: Disklabel Locations
To: <>
From: David Laight <david@l8s.co.uk>
List: tech-kern
Date: 03/08/2002 09:27:21
On Thu, Mar 07, 2002 at 09:26:28PM -0800, Matt Thomas wrote:
> Eariler today I thinking about the cross build problem regarding
> disklabel and that got me to investigate where each port keeps it's
> disklabel.  Here's what I found:
> 
> sector/offset:  port(s)
> 
> 0/0:    mvme68k next68k
> 0/64:   algor alpha amiga amigappc luna68k mac68k macppc news68k
>          newsmips pc532 pmax sun3 sun68k vax walnut x68k
> 0/128:  sparc sparc64
> 0/516:  atari
> 1/0:    arc arm bebox cobalt hpcarm hpcmips i386 mipsco mvmeppc
>          ofppc playstation2 sandpoint sbmips sgimips sh3 x86_64
> 1/64:   prep
> 2/0     cesfic hp300
> 
> Almost all ports that use MBRs use 1/0 except prep which uses 1/64.
> It seems that prep should be using 1/0 as well if there is no techincal
> reason why it can't.
> 
> atari seems to believe in > 512 byte blocks.  Not sure about the 0/0
> usage by mvme68k and next68k but it seems that at least for mvme68k
> it should be relatively simple to support either 0/64 or 1/0.
> 
> But the point is that there only a few places disklabels show up and
> it shouldn't be hard to modify both the user and kernel disklabel code
> to search the disk for a disklabel.  This would make the ability to
> cross built full snapshots much easier.

You seem to have forgotten the i386 (and others) mbr and partition table.
Also IIRC the sparc ports use solaris style partitionong.


	David

-- 
David Laight: david@l8s.co.uk