[Sevan Janiyan] They shared their research on putting together an open FPGA toolchain. Specifically, it is an open toolchain for the Sipeed Nano Tang FPGA, which Sipeed offers relatively cheaply from China. You will need to apply for official toolchain ownership and a license renewed each year. There is a limited educational version that you can use more freely, but of course, this is not enough for comfortable work.
This toolchain is based on the Epicula project, an attempt to reverse-engineer, re-implement and document the Gwin FPGA bitstream format, as well as an open tool for NextPNR (FPGA Place-and-Route). With a combination of yosys, apicula, nextpnr and openFPGAloader, [Sevan] Put together a set of commands that you can use to create gateways for your Nano Tang FPGA – block your way without any ownership restrictions. They show a basic Blinky demo, and a demo that successfully manages a parallel LCD connected to the board.
The availability of open toolchain for FPGAs is always a bit difficult. Thinking about an open FPGA toolchain? This Supercon 2019 talk of the team [Mithro] Ansel will take you fast!
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