The suggestion in the other comment about OpenWRT is the way to go, but I will also suggest you can absolutely build your own router using a PC using OpenBSD or

The suggestion in the other comment about OpenWRT is the way to go, but I will also suggest you can absolutely build your own router using a PC using OpenBSD or whatever you like. That's how it is done at scale. Of course then you go down the rabbit hole of the ME/PSP is a backdoor independent CPU and OS.. except you're reading this on a machine using it.. so.. Don't worry too much about it. OpenWRT or a PC you put together.