directly, call the function pointer (*if_input)(ifp, m). The input routine
expects the packet header to be at the head of the packet, and will adjust
as necessary. Privatize the layer 2 input and output routines, allowing
*_ifattach() to set them up as appropriate.
Some of the stuff (e.g., rarpd, bootpd, dhcpd etc., libsa) still will
only support Ethernet. Tcpdump itself should be ok, but libpcap needs
lot of work.
For the detailed change history, look at the commit log entries for
the is-newarp branch.
and for the PCI attachment of said chipset ("if_fpa"), also from Matt Thomas.
Arguably, pdq* doesn't belong in sys/dev/ic, but it's going to be shared by
various bus attachment devices at some point in the future, and there's no
other place that seems to fit as well.