Subject: Re: A new partition handling scheme: wedges
To: Charles M. Hannum <mycroft@mit.edu>
From: Ignatios Souvatzis <ignatios@theory.cs.uni-bonn.de>
List: tech-kern
Date: 01/26/1998 13:00:50
Charles writes:

> 					... By default, the installation
> tools should use whatever partitioning scheme is most appropriate for
> that particular type of machine -- on PCs, the MBR; on Amigas, RDBs;
> etc.  `Labels' should be valid on all systems if people want to use an
> architecture-neutral format (but one which is incompatible with other
> OSes).
> 
> People already have to deal with two types of partitioning on many
> systems -- one for the boot ROM, and the other for NetBSD.  Currently,
> some ports quite bogusly override what disklabel(8) does completely
> and don't even support native `labels'.

Yes, Amiga should allow translate disklabel writing back to RDB writing.
On my todo list.

However: there is no way an Amiga could directly boot off a RDB-less disk.

While it is possible to reserve some space in the RDB root block, or even
put it into a different block than zero (any of 0..15), we can not, alas, be
sure that AmigaOS RDB editors will respect a NetBSD native disklabel written
additionally to the RDB one. Well, this is a relatively minor problem... but...

AFAICT, every port which uses native disklabels stuffs them elsewhere (different
blocks, sometimes, and different offsets within the block).

What _is_ the canonical representation we should be using now? (Or do you
just say: "We don't use it consistently anyway")

Hmmm.... I start to like the "wedge" idea. It would allow 

> /dev/sd0/raw
> 	 mbr/0/raw
> 	     1/raw
> 	     2/raw
> 	     3/raw
> 	 bsd/0/raw
> ...
	 amiga/PartitionName1/...
	 amiga/PartitionName2/...

(Partitions have _names_ in Amiga RDBs, normally, and much of new-netbsd-on-
Amiga-confusion comes from either not understanding at first the concept of
Unixoid partitions, or from understanding it, not reading the fineprint, and
thus not understanding the somehow special translation NetBSD/Amiga disksubr.c
does).

Regards,
	Ignatios