Comment 9 for bug 313514

Do you really need more than 255 keycodes at the same time? If not,
remapping keycodes > 255 to values < 255 should work with the existing
protocol (though I have no idea how hard it would be to do this mapping
in xevdev, since I've never looked at it).

As for X12 planning, the transition will be painful enough, we don't want
to do it more than once this decade, so we're in the stage of gathering up
all the things that need to be changed to get them all at once - see:
http://wiki.x.org/wiki/Development/X12