Capstone ProjectAdvanced

Write a Minimal OS Kernel

Start from a bootloader and build your way up to a functional operating system kernel running in protected mode. You will implement paging, interrupt handling via IDT, a VGA text-mode driver, and a round-robin process scheduler. This project teaches you what happens between the bootloader and main().

8-12 weeks 5 milestones 20 build steps, 20 linked tasks

The whole plan below is free to read: every milestone, its build steps, how to verify it, and which tasks and visualizations to use. Tracking your progress, the completion certificate and the graded tasks it links to need a plan.

Related Tracks

Operating SystemsCPU Architecture

Prerequisites

x86 Assembly
C Programming Deep Dive

Milestones

Each milestone opens into the build order, a way to check your work, the tasks that drill its pieces, and the visualizations that show the machinery. Work top to bottom.

QEMU boots your kernel and it prints from its own code.

Build it in this order

1Set up a cross toolchain and a linker script that places your kernel at a known physical address.
2Write a multiboot header so a standard loader (or QEMU -kernel) will start you, and a stack before anything else.
3Build a GDT with flat code and data descriptors, load it with lgdt, and far-jump to reload CS.
4Write to VGA text memory at 0xB8000 so you have output before you have drivers.

How you know it works

qemu-system-i386 -kernel prints your banner, and the monitor shows CR0.PE set with CS pointing at your code descriptor.

Practise the pieces first

Set Up Cross-Compiler Build Environment for OS DevelopmentFree Understand the x86 Boot SequenceFree Switch from Real Mode to Protected Mode Write to VGA Text Mode Buffer

See how it works

Boot sequence ELF layout

Build it in your own repo

There is no upload step. You build this on your own machine, in your own repository, and tick each milestone off here as it works. Finish all 5 and you get a certificate with a verification id; connect GitHub first and a gist artifact is created alongside it.

Start with the first task Browse the prerequisite tracks