WeesyOS in Rust 🦀 (Safe)

WeensyOS is a tiny kernel that can run on bare-metal x86-64 machines (QEMU's emulated CPUs). The initial state of the kernel contains code for bootstrapping kernel, handling exceptions/syscalls, executing user-level program, and helper functions for your CPSC 323 exercises.

Host CPU-arch: x86_64, Operating System: Linux (Fedora), Application binary interface: GNU

By compiling for our host triple, the Rust compiler and the linker assume that there is an underlying operating system such as Linux (Frog Node) that uses the C runtime by default, which causes the linker errors. So, to avoid the linker errors, we compile for our own environment x86_64-weensyos.json with no underlying operating system [look how to build].

How to build

Execute only once

1. Get to the root: cd ./starter-code-rust
2. Change rust-toolchain: rustup override set nightly, you might need rustup component add rust-src --toolchain nightly-aarch64-apple-darwin for MacOS-Darwin
3. Build Target: cargo +nightly build --target x86_64-weensyos.json
4. Create Cargo Image: cargo bootimage (look for dependencies below). Image Created at ./target/x86_64-weensyos/debug/bootimage-weensyos.bin

Run QEMU-Display

Finally, run QEMU via bootimage runner cargo run --target your_custom_target.json [other_args] -- [qemu args]. EDIT: Should work with just cargo run. Note: if you are stuck in the loop and cannot exit QEMU (press q for quit), try to pkill qemu from another terminal. You can also run QEMU directly via qemu-system-x86_64 -nographic -drive format=raw,file=target/x86_64-weensyos/debug/bootimage-weensyos.bin (you can also enable QEMU graphic display if you work locally).

How to test

Current implementation provides our own simple cargo test setup using standart #[test_case] implementation that outputs directly to the terminal via serial port and quits qemu. Public test cases for the project 4/5 will be implemented throuhgout WeensyOS growth.

Environment Configs

Rust has three release channels: stable, beta, and nightly. We will need some experimental features that are only available on the nightly channel, so we need to install a nightly version of Rust. rustc 1.80.0-nightly (87293c958 2024-05-08)

Instead of writing our own bootloader, which is a project on its own, we use the bootloader crate. This crate implements a basic BIOS bootloader without any C dependencies, just Rust and inline assembly. Read more how bootimage linking works here: https://github.com/rust-osdev/bootimage.

Dependency List

1. curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
2. cargo install bootimage
3. rustup component add llvm-tools-preview
4. apt install qemu-system-x86_64 for Linux or brew isntall qemu for MacOS

Source Inspirations & How to contribute

Please, consider reading through these documentations is you plan to contribute:

    1. https://os.phil-opp.com/
    2. https://www.theseus-os.com/
    3. https://zoo.cs.yale.edu/classes/cs323/323/proj5/starter-code/

Use Cisco VPN to connect off-campus https://docs.ycrc.yale.edu/clusters-at-yale/access/vpn/ or develop locally.

Preview