cccfork / eduos-rs

A teaching operating system written in Rust

eduOS-rs - A teaching operating system written in Rust

Introduction

eduOS-rs is a Unix-like operating system based on a monolithic architecture for educational purposes. It is developed for the course Operating Systems at RWTH Aachen University and includes a modified hypervisor that simplifies the boot process to increase the intelligibility of the OS. eduOS-rs is derived from following tutorials and software distributions:

1. Philipp Oppermann's excellent series of blog posts.
2. Erik Kidd's toyos-rs, which is an extension of Philipp Opermann's kernel.
3. The original version of eduOS, which was the old teaching kernel written in C.

Requirements to build eduOS-rs

eduOS-rs is tested under Linux, macOS, and Windows.

macOS

Apple's Command Line Tools must be installed. The Command Line Tool package gives macOS terminal users many commonly used tools and compilers, that are usually found in default Linux installations. Following terminal command installs these tools without Apple's IDE Xcode:

$ xcode-select --install

Windows

To build eduOS-rs you have to install a linker, make and a git client. We tested the eduOS-rs with the linker from Visual Studio. Consequently, we suggest installing Visual Studio in addition to make and git.

Linux

Linux users should install common developer tools. For instance, on Ubuntu 18.04 the following command installs the required tools:

$ apt-get install -y git curl wget nasm make autotools-dev gcc g++ build-essential lld-8

Common for macOS, Windows and Linux

It is required to install the Rust toolchain. Please visit the Rust website and follow the installation instructions for your operating system. It is important that the nightly channel is used to install the toolchain. This is queried during installation and should be answered as appropriate.

Afterwards the installation the source code of Rust runtime and the llvm tools are required to build the kernel:

$ rustup component add rust-src
$ rustup component add llvm-tools-preview

eduOS-rs is able to run within ehyve, which a specialized hypervisor for eduOS-rs. Therefore ehyve must be installed.

$ cargo install --git https://github.com/RWTH-OS/ehyve.git

Please check if your system fullfil ehyve's system requirements.

To build the kernel, it is important to add the path to llvm-tools to the environment variable PATH. Depening on the operating systems, the tools are located at:

• Linux: ~/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/x86_64-unknown-linux-gnu/bin
• MacOS: ~/.rustup/toolchains/nightly-x86_64-apple-darwin/lib/rustlib/x86_64-apple-darwin/bin
• Windows: %USERPROFILE%\.rustup\toolchains\nightly-x86_64-pc-windows-msvc\lib\rustlib\x86_64-pc-windows-msvc\bin

Building

The final step is to create a copy of the repository and to build the kernel:

$ # Get our source code.
$ git clone https://github.com/RWTH-OS/eduOS-rs.git
$ cd eduOS-rs

$ # Build kernel
$ make build

From here, we should be able to run the kernel in ehyve:

$ make run

Overview of all branches

Step by step (here branch by branch) the operating system design will be introduced. This tutorial shows the steps to develop from a minimal kernel to a Unix-like computer operating system. Currently, following stages of development are available:

0. stage0 - Smallest HelloWorld of the World

   Description of loading a minimal 64bit kernel

1. stage1 - Cooperative/non-preemptive multitasking

   Introduction into a simple form of multitasking, where no interrupts are required.

2. stage2 - Priority-based cooperative/non-preemptive multitasking

   Introduction into a simple form of priority-based multitasking, where no interrupts are required.

3. stage3 - Synchronization primitives

   Introduce basic synchronization primitives

4. stage 4 - Preemptive multitasking

   Introduction into preemptive multitasking and interrupt handling

5. stage 5 - Support of user-level tasks

   Add support of user-level tasks with an small interface for basic system calls

6. stage 6 - Support of paging

   Add support of paging and a simple demo for process creation

7. stage 7 - Integration of an in-memory file system

   Introduce a virtual file system with an in-memory file system as example file system.

8. stage8 - Run Linux application as common process

   Start a simple Linux application (HelloWorld) on top of eduOS-rs. The application is a position-independent executable (PIE) and use musl-libc as standard C library.

Useful Links

1. http://www.gnu.org/software/grub/manual/multiboot/
2. http://www.osdever.net/tutorials/view/brans-kernel-development-tutorial
3. http://www.jamesmolloy.co.uk/tutorial_html/index.html
4. http://techblog.lankes.org/tutorials/
5. http://www.os.rwth-aachen.de
6. http://www.noteblok.net/2014/06/14/bachelor
7. https://sourceware.org/newlib/
8. http://rwth-os.github.io/eduOS/
9. https://intermezzos.github.io

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.