Can someone who understands the problem better file a PR?

> > (1) 1G, if the ROM code uses 6-byte CDBs.  (I'd've hoped such code
> > would have been stamped out before the sparc64s were made, but the
> > ability of corporations to do stupid things amazes me.)
> We're talking about IDE devices here.
> Also, I can boot my U5 from a partition starting past 2G.

 Yesterday I cracked open a Solaris9 box, and instead of throwing away all of
the "documentation" I actually read some of it.  In the booklet titled "Solaris
9 8/03 Release Notes Supplement for Sun Hardware", Chapter 3 "Open Issues" it
says:

  Booting From Partitions Greater Than 2 Gbytes (Bug ID 1234177)

  Due to PROM limitations, not all sun4m architectures boot from partitions
  greater than 2 Gbytes.  These systems fail with the following message:
   bootblk: can't find the boot program
....
  One related bug (4023466) reports a problem with re-preinstall where the boot
  image for large disks creates root partitions greater than 2 Gbytes.  System
  administrators are cautioned not to use re-preinstall on sun4m systems with
  large root disks (4 Gbytes and greater).