[nickmqb]

This FPGA is not open source by design, but this project seems fairly complete: http://www.clifford.at/icestorm/ "Project IceStorm aims at documenting the bitstream format of Lattice iCE40 FPGAs and providing simple tools for analyzing and creating bitstream files."

Lattice (the FPGA's manufacturer) seems open-minded regarding such efforts: https://twitter.com/latticesemi/status/1269115302140231682