* <https://github.com/pkerling/ethernet_mac> - doesn't do RGMII, does GMII.
* <https://github.com/enjoy-digital/liteeth> - MII RMII GMII RGMII PHY
* <https://github.com/adamgreig/daqnet/blob/master/gateware/daqnet/ethernet/rmii.py> - RMII in nmigen
* <https://github.com/pkerling/ethernet_mac> - doesn't do RGMII, does GMII.
* <https://github.com/enjoy-digital/liteeth> - MII RMII GMII RGMII PHY
* <https://github.com/adamgreig/daqnet/blob/master/gateware/daqnet/ethernet/rmii.py> - RMII in nmigen