(the relevant changes haven't been done though).
Call built binary bootxx_fat16 for consistency.
Use 'push %cs' to push a zero value in places where we had relied on %bx
being zero from much higher up the code.
into the first sector of a FAT16 filesystem and will load 'boot' (and hence)
the netbsd kernel from it.
Unlike bootxx_msdosfs this doesn't need the filesystem to have 8k of 'reserved'
sectors, and may well work on non-512 byte media (as yet untested).
