explaingit

samypesse/how-to-make-a-computer-operating-system

22,414CAudience · developerComplexity · 4/5DormantLicenseSetup · easy

TLDR

An online book and tutorial for building a minimal UNIX-style operating system from scratch in C and C++, with working code you can follow step by step.

Mindmap

mindmap
  root((repo))
    What it does
      Boot a simple OS
      Load shell interface
      Manage hardware
      Run programs
    Learning path
      CPU boot process
      Memory management
      Process creation
      Kernel hardware talk
    Tech stack
      C language
      C++ language
      Build tools
    Use cases
      Deep computer understanding
      OS internals learning
      Kernel development study
      Educational project

Things people build with this

USE CASE 1

Learn how operating systems work internally by building a minimal UNIX-style OS from scratch.

USE CASE 2

Understand CPU boot sequences, memory management, and kernel-to-hardware communication through hands-on coding.

USE CASE 3

Study process creation and scheduling by implementing core OS features in C and C++.

USE CASE 4

Build foundational knowledge for kernel development or systems programming careers.

Tech stack

CC++Assembly

Getting it running

Difficulty · easy Time to first run · 30min

Requires a C/C++ compiler and assembler toolchain; cross-compiler setup may add complexity for some platforms.

Use freely for any purpose including commercial. Keep the notice and disclose changes to the patent grant.

In plain English

This repository is an online book and tutorial that walks through how to build a simple computer operating system from scratch using C and C++. An operating system is the foundational software on a computer, the layer that manages hardware, runs programs, and provides the interface between software and the physical machine. Most people use one (Windows, macOS, Linux) without ever thinking about how it works internally. The goal of this course is not just theory but building something real: a minimal UNIX-style OS that can boot, load a command-line shell, and be extended further. The project includes source code alongside the explanations so readers can follow along step by step. You would use this if you are a programmer who wants to understand computers at a deep level, how the CPU boots, how memory is managed, how processes are created, and how the kernel communicates with hardware. It is an educational project originally written by the author in high school, then revised and translated from French to English for a broader audience. The source code is written in C and C++. No specific runtime or framework is required beyond a basic build environment.

Copy-paste prompts

Prompt 1
I want to understand how operating systems work. Walk me through the first steps of building a bootable OS using this tutorial, starting with the boot process.
Prompt 2
Show me how to set up the build environment and compile the first chapter's code from this OS tutorial.
Prompt 3
Explain the memory management section of this OS project and how it differs from user-space programming.
Prompt 4
I'm stuck on the process creation chapter. Help me debug my C code against the tutorial's implementation.
Prompt 5
What are the prerequisites I need before starting this OS-building tutorial, and how long does it typically take?
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