interprocessor communication

[<jerry%evasefor.com@localhost>]

Good afternoon list,
I have an SBC with 2 cpu each running their own netbsd kernel:

PHY--CPU1-----------logic---------CPU2---PHY
            mii bus         mii bus

after I'm done processing a packet on CPU1 how can I address it
to CPU2? Is there a kernel level interface to the MII bus I could
use for this (i.e read/write)? Or any other idea, like shared memory,
anything that you think could work?

Thanks a lot.
Jerry