RISC-V Virtual Machine

A complete RISC-V 64-bit (RV64GC) virtual machine implementation in Rust, capable of running modern operating systems like Linux (xv6) and custom bare-metal kernels. It is designed to run both natively and in the browser via WebAssembly.

Features

- Core: Full RV64GC instruction set implementation (IMAFDC + Zicsr + Zifencei).
- Memory: Sv39 Virtual Memory Management Unit (MMU) with TLB.
- Peripherals:
- UART: 16550-compatible serial console.
- PLIC: Platform-Level Interrupt Controller.
- CLINT: Core Local Interruptor (Timer).
- VirtIO: Block Device (Disk) and Network Device (Net).
- Networking:
- Native TAP interface support (Linux).
- WebSocket backend for browser/cross-platform networking.
- WebTransport backend for P2P connectivity.
- Platform:
- WASM: Compiles to WebAssembly for browser execution.
- Native: Runs as a CLI application on Host OS.

Usage

$3

Run the emulator from the command line:

``bash


Run a kernel image

cargo run --release -- --kernel path/to/kernel

Run with networking (WebSocket backend)

cargo run --release -- --kernel path/to/kernel --net-ws ws://localhost:8765

Run with block device

cargo run --release -- --kernel path/to/kernel --disk path/to/fs.img
`

$3

The VM exposes a simple API for JavaScript integration:

`typescript
import { WasmVm } from "virtual-machine";

// Initialize VM with kernel binary
const vm = new WasmVm(kernelBytes);

// Connect networking
vm.connect_network("ws://localhost:8765");

// Step execution
while (running) {
vm.step();
}
`

Architecture

The VM follows a modular design:
- cpu.rs: Instruction decoder and execution pipeline.
- mmu.rs: Virtual address translation.
- bus.rs: Memory mapping and device routing.
- virtio.rs: VirtIO device implementations.
- net.rs: Network backend abstraction.

Build

`bash


Build native CLI

cargo build --release

Build WASM package

wasm-pack build --target web
``