Last bit from tfa: "Project IceStorm Project IceStorm is a previous project that documented the iCE40 bit-stream format. It will become a part of SymbiFlow. S

Last bit from tfa: "Project IceStorm Project IceStorm is a previous project that documented the iCE40 bit-stream format. It will become a part of SymbiFlow. SymbiFlow will support the old Yosys-ArachnePnr-IceStorm flow but will also add a Yosys-VPR-IceStorm flow."