There was already a design of CADR for FPGAs [1] that does synthesize (and boot), I don't know why amszmidt needed to start again from scratch or if his design is a modification of the earlier one.

A similar comment applies to lm-3. Maybe it is built on a fork of the previous repo, it is hard to tell.

[1] https://github.com/lisper/cpus-caddr