Why I spent months writing a custom x86_64 operating system kernel from scratch in Rust

I wrote a bare-metal OS in Rust – and it taught me more about software than endless web apps

Instead of building another SaaS, I decided to dive straight into the metal. The result is Daxo OS – a custom x86_64 kernel built completely from scratch that boots on real PCs and QEMU.

What building an OS actually taught me:

* Rust won't save you from triple faults (when your PC instantly reboots with zero warning). But it does catch 90% of stupid memory bugs at compile time before you even touch the hardware.

* Writing a custom memory allocator is like assembling Lego without instructions. Now I finally understand what malloc is actually doing beneath high-level abstractions.

* UEFI and protected mode aren't magic – they’re just bits and tables that have to be in the exact right place, or the CPU shuts you down.

🔧 Under the hood:

* 4-level paging and clean Ring 0 → Ring 3 privilege transitions.

* A cooperative async task executor.

* A low-level PIO ATA driver to read disk sectors without any BIOS assistance.

The hardest part? Debugging without a proper debugger (relying purely on serial/port output). But when you spend two hours tracking down a single flipped bit in a page table, and then finally see your kernel boot up on real hardware–nothing beats that feeling.

👉 If you're curious about how memory and hardware actually work under the hood, take a look at the code (I’ve added beginner-friendly comments). If you drop a ⭐ on GitHub, it’ll be the ultimate motivation to keep building and start writing tutorials on custom driver development!

🔗 Daxo OS on GitHub → https://github.com/daxo-developer/daxo_os

#rust #osdev #buildinpublic #systemsprogramming