Note that we specifically chose the Lattice ice40 UltraPlus 5K because: - It is supported by an open-source FPGA toolchain - Has an in-package non-volatile co

Note that we specifically chose the Lattice ice40 UltraPlus 5K because: - It is supported by an open-source FPGA toolchain - Has an in-package non-volatile configuration memory (NVCM) that is lockable. This is where we'll eventually keep the FPGA configuration bitstream, including the unique per device secret. After some reverse-engineering work we're also able to program and lock NVCM with open tooling, as opposed to having to use Lattice's proprietary one.