One year of developing my own operating system
Writing an operating system from scratch is something I always wanted to do, and last year, I started working on MONOLITH, an operating system meant to make my dream true.
This operating system is meant as a fun learning experience to know more about operating systems, and to improve my programming skills in general.
1st month: GDT, IDT, Memory Management and the console
29/03/2025: The first step when developing an operating system is usually getting it to boot, here I used multiboot2 protocol boot protocol.
31/03/2025: Implemented some functions for logging to serial.
03/04/2025: Implemented a physical memory manager.
05/04/2025: Implemented a heap allocator.
11/04/2025: Added support for i386 architecture.
15/04/2025: Implemented a VGA console.
28/04/2025: Implemented a VESA video driver for i386.
2nd month
No interesting developments happened during that month, mostly due to college distractions and lack of motivation.
3rd month
02/06/2025: Switch from multiboot2 to Limine boot protocol.
03/06/2025: Drop i386 and Text VGA mode support.
08/06/2025: Add support for virtual memory management.
10/06/2025: Add support for PIT timer.
18/06/2025: Implement a VFS and a tmpfs.
4th month
23/07/2025: Add support for an initrd.
30/07/2025: Implement an ELF loader.
5th month
12/08/2025: Initial ring-3 and syscalls support.
18/08/2025: Ported microui’s demo.
19/08/2025: Added support for keyboard input in userspace.
6th month
- 13/09/2025: Added some disk I/O syscalls.
7th month
- 20/10/2025: Initial (and half-baked) support for task switching.
8th month
26/11/2025: Moved from GitHub to Codeberg.
29/11/2025: Implemented a userspace libc.
30/11/2025: Crash handling for userspace processes.
9th month
05/12/2025: Prototyped a desktop environment using Claude Opus 4.5.
05/12/2025: Implemented address space separation between processes.
06/12/2025: Removed the kernel text console.
08/12/2025: Implemented userspace malloc, realloc and free.
22/12/2025: Refactored mouse/keyboard input syscalls to use event polling instead of callbacks.
28/12/2025: Implemented scheduling.
10th month
05/01/2026: Implemented libgfx.
15/01/2026: Rewritten the desktop.
19/01/2026: Initial IPC implementation.
30/01/2026: Add support for drawing the wallpaper.
31/01/2026: Implement proper framerate locking.
11th month
15/02/2026: IPC refactoring and optimization.
21/02/2026: Added support for shared memory.
12th month
03/03/2026: Initial work on the libdesktop window protocol.
04/03/2026: Desktop performance optimization.
06/03/2026: Added support for mouse/keyboard events to libdesktop.
06/03/2026: Ported Doom.
12/03/2026: More performance optimization for the desktop.
What’s next?
This was the result of twelve months of work on this project. Despite being busy with many other things, I achieved a decent amount of progress and had a lot of fun doing so!
There’s a still a lot of work to be done on this operating system in the next year, including (but not limited to):
- A UI framework.
- A software packaging format.
- Disk drivers.
- File systems.
- Permissions/Capabilities.
- More improvements on the desktop.
- More desktop apps.
- SMP.
- PCI drivers.