On Sun, 22 Sep 2002, Henry B. Hotz wrote:

> The subject question is apropos of finding boot methods that multiple
> OF versions support.  It has been speculated on this list that OF 1
> (and others) may support FAT-16 disk partitions if the disk uses the
> MBR to partition the disk.

Do we know if OF 1 and older systems support FAT-16 file systems? The
FAT-16 idea came from OpenBSD, but they only support OF 3 systems (or so I
found last time I went to their web site).

I think what'd work better is:

1) make an HFS (not HFS+) partition, for OF 3 systems. Put ofwboot.xcf in
there. Then make installboot merely add its driver to an existing
partition set, not overwrite the whole map. That would permit it to
coexist better. Then we use said driver for OF 1, 2.0, and maybe 2.4
systems.

> What the question really translates to is:  Can you format sector 0-?
> so that OF will think a disk is MBR-partitioned, and NetBSD (and
> MacOS) will think the disk is Apple-partitioned?  Alternately, so
> that OF will think a disk is MBR-partitioned, and NetBSD will think
> it's *BSD partitioned?  Fundamentally, do APM and MBR have
> conflicting requirements on the contents of sector 0 or 1?

You have two questions in there.

1) "Fundamentally, do APM and MBR have conflicting requirements on the
contents of sector 0 or 1?" No. Iomega shipped "driver" ZIPs that were
both MBR and APM formatted. That way a mac found MacOS drivers, and a PC
found Windows ones.

2) Can we get OF to see MBR and everything else to see APM? No idea. Well,
I think MacOS will see APM first, and NetBSD will see APM first. I'm not
sure though if OF will see the MBR format first, or the APM format first.
And different versions may see a different order.

> I have this kinky thought that it would be fun to use a Microsoft
> format to get (vendor independent) Open Firmware to boot NetBSD on
> Apple computers.  Call me twisted, but it did work for floppy
> booting.  If it did work it probably wouldn't work with MacOS though.

Take care,

Bill