Can you add a module to support SPI to MII conversion, like the chip DM9051

[woodyuni]

Many SPI to MII conversions are used on microcontrollers, but there is a lack of FPGA implementation on the entire GitHub.
The difficulty of implementation mainly lies in compatibility with existing Linux drivers.

datasheet of DM9051 like this
https://www.davicom.com.tw/pddocs/DM9051(I)-12-MCO-DS-P01_03302015.pdf

[alexforencich]

The idea being to emulate the SPI end so you could interface some sort of embedded CPU to an FPGA and exchange Ethernet traffic using an existing driver? How often do you run in to a case where you have a chip powerful enough to run Linux but only have SPI interfaces available instead of something more performant like native MII/GMII/RGMII/SGMII, USB, PCIe, etc.?

Also, I generally only implement stuff that I personally need or that's externally supported in some way via consulting, licensing, etc. Is this something that would only be useful if it was freely available, or is it something that you might be interested in sponsoring/licensing?