Write Your Own 64-bit Operating System Kernel From Scratch

This respository holds all the source code for this YouTube tutorial series.

You can find the revision for a specific episode on this page.

You can find pre-built ISO files for this kernel at this repository.

Considering supporting this work via my Patreon page.

Prerequisites

• A text editor such as VS Code.
• Docker for creating our build-environment.
• Qemu for emulating our operating system.
  • Remember to add Qemu to the path so that you can access it from your command-line. (Windows instructions here)

Setup

Build an image for our build-environment:

• docker build buildenv -t myos-buildenv

Build

Enter build environment:

• Linux or MacOS: docker run --rm -it -v "$(pwd)":/root/env myos-buildenv
• Windows (CMD): docker run --rm -it -v "%cd%":/root/env myos-buildenv
• Windows (PowerShell): docker run --rm -it -v "${pwd}:/root/env" myos-buildenv
• Please use the linux command if you are using WSL, msys2 or git bash
• NOTE: If you are having trouble with an unshared drive, ensure your docker daemon has access to the drive you're development environment is in. For Docker Desktop, this is in "Settings > Shared Drives" or "Settings > Resources > File Sharing".

Build for x86 (other architectures may come in the future):

• make build-x86_64
• If you are using Qemu, please close it before running this command to prevent errors.

To leave the build environment, enter exit.

Emulate

You can emulate your operating system using Qemu: (Don't forget to add qemu to your path!)

• qemu-system-x86_64 -cdrom dist/x86_64/kernel.iso
• Note: Close the emulator when finished, so as to not block writing to kernel.iso for future builds.

If the above command fails, try one of the following:

• Windows: qemu-system-x86_64 -cdrom dist/x86_64/kernel.iso -L "C:\Program Files\qemu"
• Linux: qemu-system-x86_64 -cdrom dist/x86_64/kernel.iso -L /usr/share/qemu/
• Alternatively, install a custom BIOS binary file and link it to Qemu using the -L option.

Alternatively, you should be able to load the operating system on a USB drive and boot into it when you turn on your computer. (I haven't actually tested this yet.)

Cleanup

Remove the build-evironment image:

• docker rmi myos-buildenv -f