On Wed, 16 Aug 2000, Bob Nestor wrote:

> Bill Studenmund wrote:
> 
> All blocks on the disk other than Block0 are supposed to be described by 
> an entry in the Parition Map though according to Apple Docs.  So there 
> really should be a Map Entry which describes the boot code like what 
> you're now doing.  ;-)

True. We should follow the spec...

> Right now the boot option in mkhybrid relies on a fixed format that 
> appears to be designed to only handle MacOS boot requirements.  There's a 
> small utility that one uses to pull the boot code from a working disk in 
> a format that is acceptable to mkhybrid, and that format doesn't match 
> what we probably want to do for NetBSD.  That's why I was working on 
> "mkmacbootcd".

Oh, what I had in mind was use that utility, and have mkhybrid install
that "driver." Then we come along later and fix up that partition with a
run of installboot. This version _should_ use the existing (put there by
mkhybrid) version.

Would that not work?

> >Note: this version of installboot doesn't do the right thing for
> >non-512-byte blocks!
> >
> Shouldn't be a problem until we get to CDs and by then maybe we'll have 
> something the Start Manager can deal with.

Well, I'll see about adding it. It's not really hard to do..

> Yes, these are blocks that appear to be wedged in between the Partition 
> Map and the first partition on disk which violates the requirment that 
> all blocks on the disk are described by a Map Entry.  Many formatters 
> will just assume these are blocks allocated to the Map Partition but are 
> unused and will attempt to use them when re-partitioning the disk. One 
> disk formatter I've looked at actually uses all the blocks in the Map in 
> a round-robbin fashion, i.e. it doesn't look for an unused block at the 
> front of the map as long as there appear to be unused blocks in the Map 
> beyond the current block.

Ack!!! That's "special." :-)

> >Right. I just wasn't sure if it was really "free" space. :-)
> 
> I've never found anything that used these partitions or that documented 
> their use. I have found a couple of disk formatters that treat them as 
> free space and that's what I did in sysinst/mac68k.

Hmm... From reading the docs, it looks like the difference is that
Apple_Free is unused space, and Apple_Spare is where we've taken the
trouble to make a partition, but it's not in use. Like as some sort of
intermediate step in the formatting scheme.

Take care,

Bill