I’ve been working on an add-on board for the Novena open-source laptop, which provides an iCE40HX4K FPGA on a mezzanine board designed to fit in between the Novena and any add-on boards.
The reason this is useful is that Clifford Wolf’s icestorm project provides a fully open-source FPGA toolchain for the iCE40 that can run locally on the Novena, thereby removing the need for an x86 desktop machine when playing with FPGA projects. The Xilinx FPGA will act as a bus bridge between the iCE40 and the Novena, and (hopefully) provide access to RAM too, using a fixed, shared, FPGA design.
The board is intended to sit in the same location as the normal GPBB board would in a Novena laptop, and to provide a rotated FPGA header for the GPBB or other add-on boards to connect to, positioned such that it will sit above the SSD. This isn’t ideal, but the Novena layout is very tight for space around the FPGA connector, so it’s the best way I could fit in space for a whole second board.
At this point, I’ve drawn up a PCB design for the board, and I’ve ordered the first batch from dirtypcbs.com to try out. If anyone’s curious to look at the schematics or board, they’re available here in DipTrace format. Everything’s under the Apache 2.0 license, to match the Novena itself.