However, other device drivers support the UNIX filesystem, transferring data in response to calls to their pfxread(), pfxwrite(), or pfxstrategy() entry points. This is not the case with a network driver; it supports protocol stacks, and it transfers data in response to calls from the ifnet interface.
Note: If you are working on a network device driver that uses DMA and that can be used in a Challenge or Onyx system, you should read Appendix B, "Challenge DMA with Multiple IO4 Boards."