I think the model/goal is simpler than what you are suggesting:  When 
you set up the machine you would probably use the Apple tools to 
create 2 or 3 partitions.  They would be a) a MacOS partition, b) a 
NetBSD root partition, and optionally c) a NetBSD swap partition (if 
you don't have enough RAM for what you want to do with the machine).

No other subdivision would be necessary and when you're done you're 
done.  There is no concept of "BIOS partition" on Apple hardware 
since the "BIOS" is Open Firmware and it's supposed to use the same 
partition map that MacOS (and NetBSD) use.  I think this is actually 
simpler and less confusing than what is done with PC hardware.

If you are the kind of power user who wants separate /usr, /tmp, and 
/var partitions then you get the overhead that goes with the 
complexity.  Most partitioning tools will let you change some 
partitions and leave others alone, so I think nothing is lost in this 
model.

At 1:39 PM -0400 10/7/02, Neil Ludban wrote:
>"Darrin B. Jewell" wrote:
>>
>>  ...
>>
>>  The primary issue under discussion is how to properly use
>>  the Apple Partition Map to hold NetBSD partitions.  Initially,
>>  the thought was to use a pmPartType of "NetBSD", and
>>  keep additional information in the pmBootArgs reserved
>>  area of the partition map entry.  Since we have discovered
>>  some disadvantages to this idea, we are now considering both
>>  encoding the fstype name in the pmPartType as well as optionally
>>  encoding the extra disklabel partition information in the
>>  pmBootArgs.
>>
>>  ...
>>
>
>Are there any more general plans for NetBSD's handling of disk
>partitions?  Your direction is good for power users of Apple stuff,
>but may cause frustration for us lesser users from other OS vendors
>or architectures:
>
>Before installing NetBSD, I'd like the option to use the native OS
>and its tools to repartition the drive and reserve some space "for
>NetBSD".
>
>The installation program should be able to find/allocate the BIOS
>partition entry (or, create a minimal BIOS partition table when no
>other OS is installed or wanted).  For new users, the install
>program needs to supply appropriate NetBSD partition sizes and file
>system types/flags.  A consistent machine-independent view of the
>NetBSD partitions would make it easier for an administrator who is
>familiar with NetBSD to install on a new architecture.
>
>After install, the NetBSD fstab (at least for NetBSD partitions)
>should remain unchanged when other operating systems have made
>modifications to the BIOS partition table.
>
>As an example, FreeBSD/i386 has 3 device layers: wd0 for the whole
>disk, wd0s[1-4] for "slices" (BIOS partitions) and wd0s1[a-h] for
>disklabel partitions.  Partitions from other OSs map consistently
>into this scheme, instead of automagically showing up somewhere
>in the disklabel.
>
>-Neil


-- 
The opinions expressed in this message are mine,
not those of Caltech, JPL, NASA, or the US Government.
Henry.B.Hotz@jpl.nasa.gov, or hbhotz@oxy.edu