> 
> > Installboot man page [for sparc] tells that the first-stage
> > bootprogram is written into the superblock,
> 
> This is slightly incorrect; the boot program is never written into the
> superblock.  One boot program exists in the first 8K of the disk, just
> past the label in sector zero; writing this here is installboot's job.

Actually, boot-strap code can be installed in any partition and
installboot(8) is mostly correct in stating that the first-stage
boot program goes into the superblock, where `superblock' here is
understood to be the first 8K of the partition.

Of course, you should be careful not to dump your bootstrap code into
the first 512 bytes of the superblock where the `struct fs' (or equivalent)
is.

-pk