ZFS loader crash on sparc64 (since Oct 2012)

[Chris Ross]

  Since this is a loader crash related to ZFS, someone wisely pointed out that posting to freebsd-fs might be a good idea.  There's a long thread on the freebsd-sparc64 list about this issue, you can find at:

http://list-archives.org/2012/12/23/freebsd-sparc64-freebsd-org/changes-to-kern-geom-debugflags/f/4758203564

  But, the relevant details are that I determined that stable/9 changed for sparc64 on October 28, with revision 242230.  This was noted as a merge by avg for revision 241289, and appears to be part of a bunch of changes he made on October 6 (revs 241282-241294, plus some others nearby).

  I'm interested in getting this fixed, so I can build a bootloader that doesn't cause my sparc64 to hit a divide by zero trap.

  Please feel free to contact me with any questions about what I found.  (most of it is in the freebsd-sparc64 thread linked to above, but I'm happy to describe anything unclear or recount from memory.)

  Thanks!

                           - Chris