What Programming Languages Should You Learn for Building Your Own Operating System?

If you're interested in creating your own operating system (OS) that rivals the likes of Windows or Linux, the choice of programming languages is paramount. This guide explores the best languages to learn, especially for those interested in both kernel and system programming.

Choosing the Right Languages for Your OS

When building a new OS, you need to choose languages that can interact directly with hardware and provide the necessary low-level control. Typically, you'll learn:

Assembly and C

The two primary languages used in modern OS kernels are assembly and C. Assembly is crucial for low-level hardware interaction, as it's often required for the initial setup and configuration of your operating system. However, C is the goto language for most modern kernels due to its balance of performance and safety. Languages like C Haiku OS and Rust Redox OS demonstrate that C is just one option, but it's generally considered the most practical for direct hardware interaction.

While C is prevalent, modern languages like C , Rust, and D or Nim can offer a safer, more abstracted environment. Rust, for example, is gaining popularity for OS kernel development due to its robust memory safety and performance features. D and Nim provide similar benefits, making them viable alternatives for certain parts of the OS that don't require as much low-level interaction.

Chicken-and-Egg Problem: Garbage-Collection Languages

Using garbage-collected languages like Java or Go can be challenging for OS kernel development because these languages rely on the OS for memory management. Implementing an allocator in such a language is a chicken-and-egg problem: you can't use the allocator to implement the allocator itself. Therefore, most kernels either use C or an equivalent assembly-compilable language that allows low-level memory manipulation.

Emerging Languages: Zig

While C remains the gold standard, there's an exciting new kid on the block: Zig. Zig aims to compete with C while offering more modern features. Although it's still a work in progress, it could be a future contender for OS kernel development. However, for current projects, Zig might not be the best choice due to its evolving state.

Beyond the Kernel: Other Components of an OS

An OS is much more than just a kernel. Once you have a stable kernel and can provide a partial POSIX interface, you can use any language for building the user interface and other components.

Cross-Platform Development

Take, for instance, FreeBSD, which is almost entirely in C. Many Linux distributions ship with utilities written in Python, Perl, or C. Similarly, Windows is predominantly written in C, with parts of macOS implemented in Objective-C or Swift.

Using Garbage-Collection Languages for Higher-Level Components

For components that don't require direct hardware interaction, like user applications, you can use garbage-collected languages. An example is MirageOS, which is an OS designed for implementing microservices in lightweight virtual machines. It's implemented in OCaml, a functional programming language, and relies on libc provided by the host OS. This allows for efficient and safe development of higher-level applications.

Ensuring Good Software Practices

While the choice of language is crucial, writing good software is a matter of best practices. This includes adhering to coding standards, testing rigorously, and maintaining a clean codebase. Whether you're building a full OS kernel or creating an application that runs on top of one, these principles remain fundamentally important.

Conclusion

Building your own OS is a complex endeavor, but with the right combination of languages and a solid understanding of software engineering principles, you can create a robust and secure operating system. Whether you're gravitating toward C, Rust, or something newer like Zig, the path to creating your own OS is one of dedication and experimentation. Happy coding!