I’ve been building a small, modular Real-Time Operating System (RTOS) for ARM Cortex‑M, focusing on clarity, portability, and hackability.
It started as an experiment to see how small an RTOS kernel could be — the first version was about 400 lines, implementing memory management and a simple multithreaded scheduler. I later expanded it into a complete, readable system and wrote an English tutorial series along the way.
The project includes tutorials covering:
• memory management
• ARM exception model
• context switching
• scheduler design
• IPC and synchronization
Everything is implemented from scratch with readability in mind, and each subsystem is explained step by step.
It started as an experiment to see how small an RTOS kernel could be — the first version was about 400 lines, implementing memory management and a simple multithreaded scheduler. I later expanded it into a complete, readable system and wrote an English tutorial series along the way.
The project includes tutorials covering:
• memory management • ARM exception model • context switching • scheduler design • IPC and synchronization
Everything is implemented from scratch with readability in mind, and each subsystem is explained step by step.