µRustOS

An embedded micro RustOS for baremetal

µRustOS Getting Started (ARM + QEMU)

Set up your minimal bare-metal Rust development environment for an ARM Cortex-M core using QEMU and no_std.

0. Install Required Toolchains

sudo apt-get install binutils-arm-none-eabi gdb-multiarch

1. Install Rust

curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Follow options for default install. Then reload your shell or run:

source $HOME/.cargo/env

Verify installation:

rustc --version
cargo --version

2. Add required packages

rustup intsall nightly
rustup default nightly
rustup component add rust-src
rustup component add rust-std

3. Add the ARM Target

rustup target add thumbv7em-none-eabihf

This target supports Cortex-M4 with hardware floating point.

4. Install QEMU (Optional)

sudo apt update
sudo apt install qemu-system-arm

Verify installation:

qemu-system-arm --version

You're now ready to move on to building your Rust kernel and running it in QEMU!

Building µRustOS

Switch into the rustos directory

cd rustos

Run the rust build command:

cargo build --release # Debug build not working yet

Running µRustOS (QEMU)

Once you've built µRustOS, you can run it on QEMU with GDB debugging server:

qemu-system-arm \
  -machine lm3s6965evb \
  -kernel target/thumbv7em-none-eabihf/release/rustos \
  -S -gdb tcp::1234

Connecting Debugger to See Output

You can then connect the debugger with target extended-remote to see hello-world

gdb-multiarch target/thumbv7em-none-eabihf/release/rustos -ex "target extended-remote :1234"

To see where the "Hello World!" message was printed:

c
x/s 0x20000000
> Hello World!

Guide

Resources used:

• https://os.phil-opp.com/freestanding-rust-binary/