After reading the information about the Libre RISC-V SoC on its Crowd Supply page and its NLnet grant application, it is clear that it is a long way from a marketable SoC, but I want to congratulate Purism on helping to fund it. It shows real commitment on Purism’s part to put money into the development of the Libre RISC-V, since will be many years before it produces anything that is remotely marketable, and it could easily fail.
From what I am able to gather from looking at the source repository, the project at this point consists of Luke Leighton writing python code that uses nMigen to generate Verilog which will run in a 28nm FPGA. Leighton is figuring out how to do a lot of basic stuff that only the proprietary chip designers know how to do, but he is getting advised by Mitch Alsup, who helped design the Motorola 68000 and AMD Opteron, and using old papers on the design of the CDC 6600, which was the first supercomputer. It is really cool that old engineering knowledge is being reutilized and put in the public domain.
The other part of the project consists of Jacob Lifshay writing Rust code to implement a Vulkan GPU in software which is compiled in LLVM. The idea is that the Libre RISC-V will be optimized to run LLVM very fast, so there won’t be as much of a penalty for doing this in software rather than hardware. I would assume that the VPU will be implemented in the same way, but it doesn’t look like any code has been written for that at this point.
Leighton estimates that that the 50,000 Euro grant from NLnet is 0.5% of the total amount needed, so a total of 10 million Euros to complete it. My concern is that Leighton has his attention divided since he is also trying to crowdfund the OEMA68, a modular, environmental computer.