Help reqd : SysV/3 on VME; dev driver

[White Rabbit]

   Hopefully, someone out there might have access to the one little
piece of information I appear to be lacking, the absence of which
is giving me major problems...

  I'm trying to write a device driver for a 68030-based systam resident
on a VME bus, which has Motorola's version of System V Release 3
installed on it.  The actual '030 card is a Motorola MVME147.  The
device itself also resides on the VME bus, and takes up half
a megabyte of address space (mapped at 0xF080000).

  As far as it works, the correct values are being passed to the
driver write() routine, they are translated into the correct physical
address with phystokv(), a dummy routine #define'd in </sys/immu.h>
which leaves the address untouched.  Next step, actually accessing this
address causes a system panic at that address.  I need to know if there
is another routine I must call first, or if I must do something
to the VME controller chip to allow me access to the bus.  

  The documentation I have consists only of the standard Unix documentation,
and the various hardware manuals.  I have nothing on accessing
VME from Unix.  Neither of the device-driver textbooks I've seen
deal with the hardware/software implementation Im using, so they are
no use at this point...

  Is there anyone out there who's had to do something similar that
can tell me what I need to know?

  Thanks

Sean Ahern