nfe —
NVIDIA nForce MCP Ethernet driver
nfe* at pci?
ciphy* at mii?
icsphy* at mii?
makphy* at mii?
rlphy* at mii?
The nfe driver supports PCI Ethernet adapters based on
  the NVIDIA nForce Media and Communications Processors (MCP), such as the
  nForce, nForce 2, nForce 3, CK804, MCP04, MCP51, MCP55, MCP61, MCP65, MCP67
  and MCP73 Ethernet controller chips.
The nfe driver supports the following
    media types:
  - autoselect
- Enable autoselection of the media type and options.
- 10baseT
- Set 10Mbps operation.
- 100baseTX
- Set 100Mbps (Fast Ethernet) operation.
- 1000baseT
- Set 1000Mbps (Gigabit Ethernet) operation (recent models only).
Thenfe device driver first appeared in
  OpenBSD 3.9. It was added to NetBSD
  3.1.
The nfe driver was written by Jonathan
  Gray ⟨jsg@openbsd.org⟩ and Damien
  Bergamini ⟨damien@openbsd.org⟩.
NVIDIA refuse to release any documentation on their products.