Rysk Core

RISCV decoding and execution primitives. All you need to implement your own virtual RISCV machine.

Virtual Machine

If you are looking for a working virtual machine you want Rysk. This is a library for building RISCV virtual machines.

Usage

Please note that 0.0 versions do not guarantee a stable ABI. Anything may change at any time during early development.

First, add a dependency to your Cargo.toml:

    [dependencies]
    rysk-core = "0.0.3"

Then in your project,

    // Implement a memory management unit
    impl rysk_core::Mmu</* Register Size */> for YourMmu { /* ... */ }

    // Run your system
    fn main() {
        let mmu = YourMmu::new();
        let core = rysk_core::Core::</* Register Size */>::new(/* PC initial address */);

        loop {
            // fetch, then decode & execute
            core.execute(mmu.fetch_instruction(core.pc), &mut mmu).expect("Unable to decode instruction");
        }
    }

Goals

Current Goals

• Compatability with all platforms std supports
• Support for RV32IMA and RV64IMA
• Dependency-free
• Support for the Privileged ISA

Future Goals

• Performance
• Support for all well defined base extensions

Compliance

Note: This list does not account for errors and/or bugs in the implementation. Perfect compliance is not guaranteed

If an instruction does not behave as specified in the ISA, please leave an issue

Extension	Support
RV32I	Partial
RV32E	None*
RV64I	Full
RV128I	TBA
Zifencei	None
Zicsr	Partial
N	None
M	Full
A	None
F	None
D	None
Q	None
C	None
G	Partial
Zam	N/A
Ztso	Always

*Support for the embedded extension is low priority. Const-generics will make implementing this feature much cleaner and as such supporting RV32E is not planned until const-generics land in stable Rust.

Privilege Levels

Level	Support
Machine	Partial
Supervisor	None
User	None

Extensions

Most extensions are enabled through cargo features.

Extension	Feature
Zicsr	default
Zicsr	ext-csr

The base extension (RV32I, RV64I) is set through the generic register type used. MXLEN is a set at compile time and therefore cannot be changed by RISCV programs (ie. misa[MXLEN] is read-only).