Subject: Re: EFI GPT and wedges/disklables on amd64 i386 and ia64
To: Jonathan A.Kollasch <jakllsch@kollasch.net>
From: Jason Thorpe <thorpej@shagadelic.org>
List: tech-misc
Date: 03/01/2006 17:09:26
On Feb 28, 2006, at 9:54 PM, Jonathan A. Kollasch wrote:
> As there are now shipping EFI-based i386 machines, we should consider
> how the partitioning will work on all the EFI machines. Since EFI
> itself
> may often need to read (and write) into at least one partition, a
> simple
> disklabel-only scheme won't work. Are wedges over the GPT[1]
> partitions
> the way to go? Or do we do a i386-like GPT+disklabel thing? I
> believe
> FreeBSD/ia64 is using a GPT-only scheme.
Wedges will be the solution for GPT. There are still some wedge
issues to work out yet. I have plans to work on this some more in
the near future.
> For starters the GPT partitioning program from FreeBSD should be
> ported
> and imported. It uses some FreeBSD-specific ioctls for determining
> size of the disk, and I couldn't find an equivalent in NetBSD. I'd be
> willing to try to get it ported if I got some pointers in this area.
I'm not so sure the GPT program from FreeBSD should be imported as-is.
> Also, for the GPT+disklabel possibility a gptlabel(8) program
> similar to
> mbrlabel(8) may need to be written. Or is a wedges-based system
> with only
> the GPT on disk the way of the future?
Wedges only, please. The disklabel in-core format can't express what
GPT can do.
>
> Jonathan Kollasch
>
> [1] http://en.wikipedia.org/wiki/GUID_Partition_Table
-- thorpej