Most of us use computers without ever thinking about what truly powers them. Beneath the apps, windows, and smooth interfaces lies something far more complex — the operating system (OS). It quietly manages hardware, runs programs, and coordinates every digital task we perform.
But what if you wanted to build one yourself?
Creating an operating system from scratch isn’t about assembling physical components. It’s about designing the software intelligence that controls them. It’s a deep dive into the core mechanics of computing — where you move from being a user of technology to an architect of it.
Building a System Like Building a City
Designing an OS is a bit like planning a city. Before anything functions, you need infrastructure — roads, power, and communication networks.
In OS development, that infrastructure begins with setting up the right development environment. Beginners often rely on structured guides such as Samy Pesse’s How to Make a Computer Operating System, which walks through the foundational steps.
A key part of preparation is virtualization. Tools like Vagrant and VirtualBox create isolated virtual machines where you can experiment safely. Think of this as your private workshop — a place to test, break, rebuild, and refine without affecting your main computer.
Choosing the Right Foundation
Like any construction project, the materials you choose matter. Developers typically begin with a base operating system image to run inside their virtual environment.
Older tutorials may reference outdated versions of Linux, but modern developers often select stable, supported alternatives that still provide manageable complexity. Once chosen, these base images are configured using a Vagrantfile, which acts like a blueprint — defining how the virtual machine should behave and what resources it needs.
With this environment ready, the real work can begin.
Teaching the System to Understand Storage
One of the most fundamental skills an operating system must have is managing data storage — reading, writing, and organizing information on disks.
Imagine a hard drive as an empty landscape. Disk partitioning divides that space into structured regions, each with a defined purpose. At the very start of the drive sits the Master Boot Record (MBR), which contains essential information about how the disk is organized.
Within it lies the partition table — a map that tells the system where each section begins, how large it is, and how it should be used. Structures like partition entries store technical details such as boot flags, addressing information, and logical block locations.
Without understanding this structure, an operating system simply wouldn’t know where data lives or how to access it.
Making Sense of Errors: The Role of Logging
Even a functioning OS needs a way to communicate what’s happening internally — especially when something goes wrong. That’s where logging becomes essential.
Debugging low-level software can feel like navigating in the dark. A logging system acts like a flashlight, illuminating what the system is doing at any moment.
Early OS projects may not have sophisticated logging frameworks, but developers can build simple message systems using core kernel functions and string utilities. Messages are often categorized by severity — DEBUG, INFO, WARNING, or ERROR — making it easier to trace problems.
Functions similar to the well-known printk can output these messages to the console, and environment settings can control which messages appear. This transforms debugging from guesswork into a structured investigative process.
A Journey Into the Heart of Computing
Building an operating system is not a quick project. It demands patience, precision, and a willingness to understand computing at its most fundamental level.
You’re not just writing code — you’re creating the logic that allows silicon to behave intelligently. Every memory allocation, hardware instruction, and system call is part of a carefully designed structure that makes modern computing possible.
For those curious enough to attempt it, OS creation is more than a technical exercise. It’s a journey into the digital mind of the machine — one line of code at a time.