CHERIoT Specification and Sail model

This repository contains the specification for the CHERIoT ISA. It consists of a document written in latex which includes excerpts of the reference model written in Sail. The current draft architecture document built from this repository contains a full description of the ISA and its intended use by CHERIoT RTOS. The Sail code is used to build an instruction set simulator which is included in the CHERIoT RTOS dev container. It can also be used to prove properties of the ISA using Sail's SMT support.

The architecture is based on the CHERI specification. The code is derived from sail-cheri-riscv and uses sail-riscv as a submodule.

Building

The easiest way to use the emulator is to use the dev container for the CHERIoT RTOS as described in the getting started guide.

Alternatively, if you wish to build from source you must first install dependencies, including Sail. For example, on Ubuntu 20.04 we have tested:

sudo apt update
sudo apt install opam z3 libgmp-dev
opam init
opam install sail

Then clone the repo:

git clone --recurse-submodules https://github.com/CHERIoT-Platform/cheriot-sail
cd cheriot-sail

Finally build the C emulator:

make csim

This will produce an executable in c_emulator/cheriot_sim that can be used to run ELF files produced by the CHERIoT compiler.

To build the documentation you must have biber, latexmk and pdflatex and have setup your opam environment as above. Then follow the following commands:

pushd archdoc
make
popd

This will create a file located at archdoc/cheriot-architecture.pdf.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.