I've started to populate sys/dev/vme with some MI VMEbus support and
configuration routines.  The exact shape this VME support should take
is still very much open to enhancements and debate. Much of which will
depend on the needs of ports capable of supporting VME busses. 

There are two sample drivers included: a IE (i82586) ethernet front-end
and a XD (Xylogics 753) disk driver. These drivers are based on the
sparc versions and still have some sparc-idiosyncracies in them.

Currently, the bus routines just define auto-configuration structures
and hooks to an MD "vme chipset":

	struct vme_busattach_args: contains bus.h defined tags that
				   identify the MD VME bus implementation

	struct vme_attach_args: auto config data for attaching VME devices

	struct vme_chipset_tag: hooks for mapping devices into VME
				address space, and setting up interrupts


Notibly missing yet: DMA handling.

-pk