Once you've located the correct driver for your hardware, use io-pkt* to start the driver. You can either start the driver as an option to io-pkt*, or you can mount the driver into an already running copy of io-pkt*.
For example, to start io-pkt-v4-hc with the devn-el900.so (3Com 905) module, type:
io-pkt-v4-hc -d el900 -t tcpip &
To mount the module, type:
io-pkt-v4-hc -t tcpip & mount -T io-pkt devn-el900.so