horahh/baremetal_hello_world

Explore Rust Bare metal Programming

Basic Example

This a minimal example how to create a bootable disk image with the bootloader crate.

This code is based on basic example from repository located at:

https://github.com/rust-osdev/bootloader

The code was separated from the booloader to experiment solely with bareprogramming standalone applications.

Structure

The kernel code is in src/main.rs. It requires some special build instructions to recompile the core library for the custom target defined in x86_64-custom.json. It depends on the bootloader crate for booting..

The simple_boot sub-crate is responsible for combining the kernel with the bootloader to create bootable disk images. It is configured as a custom runner, which means that cargo will automatically invoke it on cargo run. The compiled kernel will hereby be passed as an argument.

Enable Rust nightly

rustup default nightly rustup component add rust-src --toolchain nightly-x86_64-unknown-linux-gnu

Installation Dependencies

1. rustup update
2. rustup target add aarch64-unknown-none thumbv7em-none-eabihf
3. rustup component add llvm-tools-preview
4. cargo install cargo-binutils cargo-embed
5. install qemu

based on: https://google.github.io/comprehensive-rust/bare-metal.html

Build Commands

The .cargo/config.toml file defines command aliases for the common commands:

• To build the kernel, run cargo kbuild.
• To build the kernel and turn it into a bootable disk image, run cargo kimage (short for "kernel image"). This will invoke our boot sub-crate with an additional --no-run argument so that it just creates the disk image and exits.
• To additionally run the kernel in QEMU after creating the disk image, run cargo krun.