[syslinux] isohybrid and partition type 0x17

[Andres Salomon]

On Tue, 16 Apr 2013 12:59:22 -0700
"H. Peter Anvin" <hpa at zytor.com> wrote:

> On 04/16/2013 09:19 AM, Gene Cumm wrote:
> > 
> > http://en.wikipedia.org/w/index.php?title=Partition_type&diff=510296573&oldid=510086292
> > 
> > No external reference cited.  No reference to what "CHRP" means
> > (perhaps
> > http://en.wikipedia.org/wiki/Common_Hardware_Reference_Platform ).
> 
> Yes, CHRP is Common Hardware Reference Platform which is a PowerPC
> architecture.
> 
> > I'd certainly consider it "made up" by Matthiaspaul.  Perhaps
> > http://www.openfirmware.org/ofwg/bindings/chrp/chrp1_6d.ps page 56?

That's an "unapproved draft", here's an official version (that is
slightly different):
http://stuff.mit.edu/afs/sipb/contrib/doc/specs/protocol/chrp/chrp1_7a.pdf

"11.1.1.1. FDISK Partition Types"

> > 
> > To me, this feels like arbitrary application of a foreign standard
> > (one that was specifically targeted to a completely different
> > architecture).
> 
> Pretty much, although it may have been appropriate, I don't know (but
> why would CHRP use the crazy MS-DOS partition format)?
> 

"The following algorithm is intended to support raw (uninterpreted)
disks, raw partitions of disks beginning with an FDISK partition map,
and files on FAT and ISO-9660 file systems both within FDISK partitions
and by themselves on disks without a partition map."

I'm not going to pretend I know why they're doing that; however, given
that one of the authors of that document (Mitch Bradley) is also the
author of OLPC's OFW, I wouldn't be surprised if its ISO-9660 driver
was originally written to support CHRP devices.  The svn history of
OFW only goes as far back as 2006, and this driver was included in the
initial import.

So it appears that 0x96 was "made up" for CHRP around or earlier
than 1996. The question is whether it's accepted and used elsewhere (the
windows test would be a good start, if someone can point me at the
original windows-choking-on-partition-type-0x83 bug report).