Write Your Own 64-bit Operating System Kernel #1 - Boot code and multiboot header

In this series, we'll write our own 64-bit x86 operating system kernel from scratch, which will be multiboot2-compliant. In future episodes we might expand out to other architectures and bootloaders.

In this first episode, we write our initial boot code and also include a multiboot2 header so that it can be understood by bootloaders.

This operating system will be primarily written in C, but we'll need some assembly as well for any of the hardware-specific code.

All the code is available on GitHub:

Thanks to top Patreon supporters Helge Sverre Hessevik Liseth and Kaas at the time of uploading this video!

Consider becoming a Patreon supporter below:

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Useful resources (in no particular order):

And some youtube videos such as:

[CodePulse]

*Getting an error?*
If you are using linux or macos, use *$(pwd)* instead of *$pwd* at 3:02

[mr.lon]

I don't understand a single fuck of what is going on but i like it

[christianloizou]

"So in here we're gonna have to do a few things. I don't even know what they do" - Literally every programmer ever.

[networkedsapien]

This is the kind of dopamine releasing undefiled programming content I've been looking for...this is programming bliss ...this is learning

[mxw]

I am gonna love the episode 2 and btw don't give up on this series bc it's so cool

[DarkPlaysThings]

I have never been this excited in my life :D

[cristianpaulnitulescu]

Pls don't tell me you have given up on this series, this is exactly what I need man c'mon . You are doing an amazing job would love it if you finish this.

[samuelbarber]

10:02 for anyone curious, the timeout number is the number of seconds in the multiboot grub screen before it auto-boots into the default os and the default value is the os to boot into. So what the code does is tell grub to immediately boot into our os.

[xxMrPHDxx]

This is the best Youtube recommendation I get so far. Thank you for this 😃

[BorisBrodski]

This is so cool! It looks totally simple, but it is actually very hard to setup such an environment yourself. A lots of work. Nice job!

[TheRukisama]

Awesome video! Building an OS (and low-level programming in general) has been an interest of mine for years, but I've only ever dabbled in it. Thanks for making this! Looking forward to more in this series!

[xA]

Years ago I used MS-DOS debug utility to implement a tiny operating system that was created on paper. It booted and ran a command shell which indirectly made calls to other components such as the TTY and its own file system. The entire system lived on a floppy disk. If I remember the entire operating system was less than 1024 bytes but it worked albeit limited functionality was implemented; it was just a personal project to help me learn about the boot process, the master boot record, the kernel, and the file system. I was inspired by a book that I had read and it is still on one of my book shelves.

[CodePulse]

If you get a command not found error when running qemu, make sure you have it added to your path. "C:\Program Files\qemu" on Windows.

[theotherquou]

I wake up on my birthday to see that codepulse has made a new video! Straight to computer it is.

[Quaggabagel]

This is really good timing, just 5 days ago I was looking for a tutorial on how to make an OS if only I saw this which was posted the day before

[yksw]

I've written several systems, and they were the most exciting experiences I ever had. I suggest every programmer to try it at least once. As shown here, it is extremely simple. 35 years ago, I had also to write a compiler and a linker, and everything else :-)

[aspectreishauntingeurope]

Man i am excited! I was trying to find something on this topic for so long! Keep up the amazing videos!

[logix]

Note: That "docker run" command near the start doesn't work if VSCode is using PowerShell as the terminal. Switch to command prompt (click the plus button next to the dropdown list and if you're asked to choose a default terminal, choose Command.

[tonytoz]

Excellent series, please keep it going.

Some setup help for people who want to type along.

Docker:
* Install Docker Desktop (Windows for me)
* Install the VS Code extension
* Ctrl+, for settings
* enter "docker"
* Under Run Interactive - click "Edit in settings.json" and enter the following. Remember to change your project source folder.
* "docker run --rm -it -v <your project source folder>:/root/env myos-buildenv",
* You can now right click on the docker images\myos-buildenv\latest and choose run interactive to correctly have your container using the project source folder

QEMU:
* add -L "C:\Program Files\qemu" to the command line argument. Not DO NOT add a trailing \
I found this necessary even when adding the qemu path to the system PATH environment variable.
ie. qemu-system-x86_64.exe -cdrom .\dist\x86_64\kernel.iso -L "C:\Program Files\qemu"

I hope this helps.

[lbproductions]

I've been waiting so long for this!!!