# RustSBI

RISC-V Supervisor Binary Interface ([SBI](https://github.com/riscv-non-isa/riscv-sbi-doc/)) implementation in Rust; runs on M-mode.

[![crates.io](https://img.shields.io/crates/v/rustsbi.svg)](https://crates.io/crates/rustsbi)
[![Documentation](https://docs.rs/rustsbi/badge.svg)](https://docs.rs/rustsbi)
![License](https://img.shields.io/crates/l/rustsbi.svg)

## Build this project

RustSBI is usually used as a library or dependency. If you wish to, you may build RustSBI library itself using the following command:

```bash
# If you don't have the cross compile target installed, install it first
rustup target add riscv64imac-unknown-none-elf
# Build this project as library
cargo build --target riscv64imac-unknown-none-elf
```

The build should finish without any errors.

If you see any error like `invalid register a0: unknown register`, it's likely that you cross built this project
into platforms other than RISC-V. RustSBI adapts to RISC-V SBI interface, you may cross build this project
into any bare metal RISC-V platform targets.

The target platform of RustSBI is usually a bare metal target. Under normal circumstances these targets in Rust
would start with `riscv??-` and end with `-none-elf`. If a non bare metal target is built to, it would throw
build error in `riscv` dependency crate or RustSBI library itself.

## Binary downloads

RustSBI is provided with separate library and binary projects, this is the repository for RustSBI library. 
For specific platforms, you may visit implementation specific projects depending on the platforms you need. 
Chip, system and platform vendors should provide RustSBI implementation for dedicated platform as a part of platform software support package.

There are packages exists on [awesome-rustsbi](https://github.com/rustsbi/awesome-rustsbi): it is a curated 
list of awesome things related to RustSBI, which includes some implementation projects maintained by 
individuals or the community. You may find binary downloads for useful platforms on awesone-rustsbi.

## Features

- Functional and extensible operating system runtime
- Fully support to RISC-V SBI specification v0.3
- Adapted for operating system kernel models on your choice
- Written in Rust
- Competitive to OpenSBI with most of its function
- Bundled with a test framework for SBI implementations
- Empower support, compatibility for different platforms

## Frequently asked questions

1. Can I use RustSBI on C based kernels?

Yes, you can! RustSBI strictly follows RISC-V SBI standard. All features are prepares for all programming languages,
as long as they support RISC-V SBI defined calling convention. 

If your kernel language supports other SBI implementations, usually it will support RustSBI in the same way.

## Talks and documents

This project is originally a part of rCore Summer of Code 2020 activities, 
inspired by [MeowSBI](https://github.com/meow-chip/MeowSBI) and other similar projects.
Now it is capable of running rCore-Tutorial and other OS kernels on wide supported RISC-V devices.

Blog article (Chinese):

- [Rust in Embedded World](https://www.yuque.com/chaosbot/rust_magazine_2021/biydon), Jan 2021
- [rCore Operating System Lab Final Report](https://github.com/luojia65/rcore-os-blog/blob/master/source/_posts/os-report-final-luojia65.md), Aug 2020

Slides (Chinese):

- [HSM and SRST module on RustSBI](https://github.com/luojia65/DailySchedule/blob/master/RustSBI%E4%B8%AD%E7%9A%84HSM%E6%A8%A1%E5%9D%97.pdf), Nov 2021
- [Design and Implementation of RustSBI](https://github.com/luojia65/DailySchedule/blob/master/2020-slides/RustSBI%E7%9A%84%E8%AE%BE%E8%AE%A1%E4%B8%8E%E5%AE%9E%E7%8E%B0.pdf), Dec 2020
- [The Rust Embedded System Development](https://github.com/luojia65/DailySchedule/blob/master/2020-slides/Rust%E5%B5%8C%E5%85%A5%E5%BC%8F%E5%BC%80%E5%8F%91.pdf), Dec 2020
- [Operating Systems on Rust and RISC-V](https://github.com/luojia65/DailySchedule/blob/master/2020-slides/Rust%E8%AF%AD%E8%A8%80%E4%B8%8ERISC-V%E6%93%8D%E4%BD%9C%E7%B3%BB%E7%BB%9F.pdf), Aug 2020

## Notes on platform implementation

1. RustSBI should be used as a library. Under normal circumstances, RustSBI platform can be implemented
   with embedded Rust's `embedded-hal` libraries.
2. Contributions are welcomed! We welcome to implement and test RustSBI for both FPGA cores and real cores.
   Implementations for emulators are also welcomed. If you are ready, start your own binary project and use
   RustSBI in it!
3. If there is a bug in RustSBI project itself, fire an issue or pull request to let us know! 

## License & Copyright

This project is licensed under either of

- MIT license ([LICENSE-MIT](LICENSE-MIT) or [http://opensource.org/licenses/MIT](http://opensource.org/licenses/MIT))
- Mulan PSL v2 ([LICENSE-MULAN](LICENSE-MULAN) or [https://opensource.org/licenses/MulanPSL-2.0](https://opensource.org/licenses/MulanPSL-2.0))

Documents from RISC-V SBI Specification are used in this project. These documents are (C) RISC-V Founcation 
under Creative Commons Attribution 4.0 International License (CC-BY 4.0).
The full license text is available at https://creativecommons.org/licenses/by/4.0/.