I haven't yet looked into this fully, mainly because it's the last stage
   of the project. However, mrg has pointed out that we already support
   dynamically assigning major numbers because the switch tables can be built
   dynamically at run time. If I recall correctly he mentioned he made this
   work with LKMs.

just to be clear and not take others work as my own, i didn't do
more than make vnd(4) LKM use it.  other developers changes to
devsw interfaces made it possible to do in a sane/portable fashion
without hard coding every platforms major/minor for vnd(4).


.mrg.