Section Mixed HDL on Fomu of the FPGA Tomu Workshop contains Makefile based examples for synthesising mixed language (VHDL and Verilog) designs using open source tooling. Find sources at im-tomu/fomu-workshop: mixed-hdl/blink.
NOTE: The workshop uses im-tomu/fomu-toolchain, which is based on open-tool-forge/fpga-toolchain. Hence, makefiles expect ghdl-yosys-plugin to be built into Yosys. Other packaging solutions can be used too, but using ghdl-yosys-plugin as a module requires adding -m ghdl
to the yosys call in the Makefile.