RustV OS Lab

RustV OS Lab is a RISC-V operating system prototype written in Rust. It follows the bare-metal learning path: take control at 0x8000_0000, clear .bss, enter Rust, talk through the QEMU virt UART, model physical pages, sketch Sv39 page tables, route traps, and build a small scheduler/syscall layer.

Features

• RISC-V virt memory map notes and linker script
• Assembly boot path that parks secondary harts and clears .bss
• no_std Rust kernel entry point and panic handler
• NS16550a UART console with print! and println!
• MMIO helpers using volatile reads/writes
• Page-grained physical allocator model
• Sv39 page-table entry helpers and virtual-address decoding
• Trap cause decoding and trap frame model
• Cooperative task scheduler model
• Minimal syscall dispatcher
• QEMU, GDB, and build workflow documentation
• push_project.sh configured for the requested repository and date window

Requirements

rustup install nightly
rustup target add riscv64gc-unknown-none-elf
cargo install cargo-binutils

You also need QEMU:

sudo apt install qemu-system-misc

Build

cargo build

Run

make run

Layout

src/
  asm/boot.S          Boot hart selection and BSS clearing
  console/            UART-backed formatting macros
  drivers/            MMIO and NS16550a UART driver
  lds/virt.lds        QEMU virt linker script
  memory/             Page allocator, regions, Sv39 helpers
  riscv/              CSR wrappers and wait-for-interrupt helpers
  sync/               Spin lock primitive
  syscall/            Educational syscall model
  task/               Cooperative scheduler model
  trap/               Trap frame and trap cause decoding

Roadmap

1. Boot one hart and park the rest.
2. Clear .bss, set the stack pointer, and jump into Rust.
3. Initialize UART output through MMIO.
4. Decode traps and page faults.
5. Manage physical pages with descriptors.
6. Build Sv39 mappings for kernel text, data, heap, and MMIO.
7. Add a timer tick and cooperative task scheduler.
8. Add user-mode experiments and syscall validation.
9. Explore virtio block and network devices.

This repository is a lab, not a production OS. The point is to make each kernel subsystem visible, readable, and easy to extend.