Hi Luke In order to be truly libre, you've got to remove AXI from the RISC-V implementation and replace it with TileLink or another bus, which isn't patented by a company. Also I would strongly discourage you from using ARM patented solutions, this might most certainly come back in the future to hunt you.
-lev
On Monday, 23 September 2019 2:56:31 PM HKT Luke Kenneth Casson Leighton wrote:
[please do remove all but libre-riscv-dev when replying, thx]
https://libre-riscv.org/nlnet_proposals/
A series of funding proposals, each for EUR 50,000, have been submitted to NLNet. These are for charitable donations and may be given to either individuals or to Universities (not to Corporations) for completion of an allotted milestone.
The basic idea is to think through and plan for commercial completion all of the tasks that will make the Libre RISC-V SoC a success. It's a lot! We have the following:
- a second Vulkan 3D driver, which will be a port of AMDVLK. similar to
swiftshader, for the Libre RISCV SoC, except taking into account the Vectorisation, predication and custom accelerated opcodes.
- a video acceleration initiative: with NEON assembler being up to the
job of decoding 720p video on recent ARM64 processors, the idea is to design instructions that will do the job and then follow through getting the code upstream.
- two related proposals which, in combination, will result in an actual
180nm ASIC being taped out at TSMC.
- a formal mathematical proof of the hardware design, proving inviolate
guarantees of its correctness. this because although auditing the code is possible, it is both laborious, error prone, and could be compromised. mathematical proofs may be run by anyone and are inviolate.
- an augmentation of gcc to support the processor’s parallel and
vectorisation capabilities.
Yes, really: 180nm ASICs only cost around EUR 600 per square millimetre, and with around 20 or so mm^2 it is completely within the realm of possibility for an NLNet Grant to fund a test ASIC. With each square millimetre being around 40,000 gates in 180nm, that's around 800,000 gates, which is enormous.
We would then have a proven ASIC, and moving up to 40nm or below, which would require around the USD 2m mark, is a far less risky proposition.
The irony is that whilst these funding proposals are quite easy to write, we also need to find people willing to do the work! In particular, we need at least one EU Citizen per project. They do not have to be permanently resident in the EU, they do however need an EU residence. Yes this includes the UK at the time of writing.
This is an extremely important strategic project that puts you - software libre developers - in the driving seat of modern technology instead of picking up the reverse engineering crumbs that fall from the Corporate table with at least a 2 year delay.
If you would like to help and actually receive donations (directly transferred) from NLNet for doing so, please do contact me directly or on libre-riscv-dev.
L.