This project aims to enable unlimited, independent, efficient, and robust composition of diverse RISC-V composable extensions, hardware composable extension units (CXUs), and software libraries.
Eventually the work will include specifications, hardware packages, and software libraries. Presently the repo includes only the Draft Proposed RISC-V Composable Custom Extensions Specification (PDF), with hardware CXU core packages, software libraries, tests, and other collateral to come.
This new talk video accompanies the spec, presenting the Design and Rationale of the Specification (slides PDF) which explains why RISC-V needs standards-based composable extensions to bring order and reuse to the custom extensions Wild West. The talk details the design of the various interop interface standards proposed in the spec, and importantly, it explains why they are they way they are.
As of fall 2023, we are working to submit this work as a basis of a proposed RISC-V Composable Extensions Task Group. Please review the draft Composable Extensions (CX) Task Group Charter.
This work summarizes years of ongoing discussions and prototyping by (alphabetical order): Tim Ansell, Tim Callahan, Jan Gray, Karol Gugala, Olof Kingdren, Maciej Kurc, Guy Lemieux, Charles Papon, Zdenek Prikryl, Tim Vogt.
The spec is built using the RISC-V International asciidoc docker tools image
riscvintl/rv-docs.
Linux: install docker.
Windows: install a WSL2 Linux distro, plus docker or Docker Desktop.
Run:
cd spec
./docker-make.sh
Copyright (C) 2019-2022, Gray Research LLC jan@fpga.org.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0.html.
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
The specification subdirectory incorporates design elements from the RISC-V documentation template https://github.com/riscv/docs-dev-guide which uses a Creative Commons Attribution 4.0 International ("CC BY 4.0") license.
RISC-V is a registered trade mark of RISC-V International.
