I Built a 64-Bit OS from Scratch: BIOS/UEFI, GUI, Networking, a Browser, and DOOM

BoltOS: a from-scratch 64-bit operating system

I built BoltOS as a 64-bit operating system in C and x86-64 assembly, starting with the boot chain rather than an existing kernel or bootloader. It supports both legacy BIOS and UEFI boot paths—no GRUB, no Multiboot, and no external OS libraries.

This is an active project with roughly 41,000 lines of first-party code. I am sharing it to get feedback from people interested in operating systems, systems programming, and bare-metal development.

What is implemented

A custom BIOS MBR and UEFI boot chain that enters a 64-bit higher-half kernel

I Built a 64-Bit OS from Scratch: BIOS/UEFI, GUI, Networking, a Browser, and DOOM

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