On Thu, 5 Dec 1996, Bill Studenmund wrote:

> Data point: the mac68k port uses MacOS partitioning, and puts one NetBSD
> filesystem per partition. We don't have a traditional unix disklabel.
> 
> Idea: I've been thinking about increasing the # of partitions too. As I
> understand it, the amiga port already has gone to 16 partitions! So the
> problem of kernel code supporting #partitions != 8 has been dealt with.

I dealt with the technical problems on the mac68k port almost a year ago;
provided that all access to the disk devices on the i386 is done using the
DISKPART/DISKUNIT/MAKEDISKDEV macros, things "should" work fine.  (Be
warned that I don't know how it interacts with the normal BIOS/DOS
partitioning, though.)  Previously, there were assumptions that the device
had a 3-bit partition number `field', which is obviously bogus. :-)

> As I understand it, the one problem (which is large) is that the kernel's
> idea of # partitions and /dev's idea MUST match, or else you loose BIG
> TIME. So kernels from before the change won't work after, and ones from
> after won't work with non-updated systems. A royal mess!

Definitely, and is the reason that I didn't push hard to make this change
on the mac68k port at the time.

> But I've got an idea. The kernel can figure out what it should do. Just
> have the kernel go out and look on the root file system. /dev/sd1a (or
> /dev/wd1a or /dev/whatever1a) will tell us the minor # set up. Thus one
> kernel could boot with either type of system.

I don't see any reasonable way to implement this without having to modify
a lot of code.

--scott