# Operating System development tutorials in Rust on the Raspberry Pi

## Notice

**This is a work-in-progress rewrite, started on September 2019. I will first add
code and minimal READMEs, and later write accompanying full-fledged tutorial
text.**

- The code written in these tutorials supports and runs on the **Raspberry Pi 3** and the **Raspberry Pi 4**.
  - Tutorials 1 till 5 are groundwork code which only makes sense to on QEMU.
  - Starting with [tutorial 6](06_drivers_gpio_uart), you can load and run the kernel on Raspberrys and observe output over UART.
- For practical purposes, the kernel will be a classic [monolith].
- For editing, I recommend [Visual Studio Code] with the [Rust Language Server] extension.
- Check out the `make doc` command to browse the code with HTML goodness.
- Note that the branch is subject to frequent force pushing. If updates happened
  since you last visited, make sure to clone a clean copy to be safe.

_Cheers,
[Andre](https://github.com/andre-richter)_

 [monolith]: https://en.wikipedia.org/wiki/Monolithic_kernel
 [Visual Studio Code]: https://code.visualstudio.com
 [Rust Language Server]: https://github.com/rust-lang/rls

## Prerequisites

Before you can start, you'll need a suitable Rust toolchain.

```bash
curl https://sh.rustup.rs -sSf  \
    |                           \
    sh -s --                    \
    --default-toolchain nightly \
    --component rust-src llvm-tools-preview clippy rustfmt rls rust-analysis

cargo install cargo-xbuild cargo-binutils
```

## USB Serial

It is highly recommended to get a USB serial debug cable. It also powers the Raspberry once you
connect it, so you don't need extra power over the dedicated power-USB. I use a bunch of
[these](https://www.amazon.de/dp/B0757FQ5CX/ref=cm_sw_r_tw_dp_U_x_ozGRDbVTJAG4Q).

You connect it to the GPIO pins 14/15 as shown beyond.

[Tutorial 6](06_drivers_gpio_uart) is the first where you can use it. Go to the README there
for instructions on how to prepare the SD card to run your self-made kernels from it.

![UART wiring diagram](doc/wiring.png)

## License

Licensed under the MIT license ([LICENSE-MIT](LICENSE) or http://opensource.org/licenses/MIT).