AAOS — Air-Azi Operating System

A minimal, educational operating system built from the ground up in C and Assembly, designed to run on a custom MIPS CPU.

Overview

AAOS (Air-Azi Operating System) is a hobby OS project that implements core operating system concepts, primarily targeting the content covered in China's 408 Computer Science Comprehensive Examination (Data Structures, Computer Organization, Operating Systems, Computer Networks).

The project's architecture is deeply tied to the author's companion hardware project:

• MIPS — a 32-bit, 5-stage pipelined MIPS CPU with a Harvard architecture, written in Verilog, designed for FPGA synthesis.

The instruction set used by AAOS is based on the custom ISA defined in the MIPS project. The long-term goal is a self-hosted system where the OS, compiler, and assembler all target the same custom hardware.

Current Status

⚠️ Very early stage. Currently contains a minimal x86 boot sector (boot.asm) as a starting point, with GDT setup and the standard 0xAA55 boot signature. The boot code will be adapted to the custom MIPS ISA as the companion CPU and toolchain mature.

Contents:

• boot.asm — Initial x86 boot sector (placeholder, pending MIPS port)
• README.md — This file

Project Goals

• Build a complete operating system in C and Assembly
• Implement classic OS mechanisms relevant to the 408 exam syllabus:
  • Process and thread management
  • Memory management (paging, segmentation)
  • File systems
  • Device drivers
  • Interrupt handling
• Target the custom MIPS CPU from the MIPS project
• Develop a custom assembler and C compiler for the same ISA
• (Future) Add SNN (Spiking Neural Network) acceleration support

Building & Running

Build and run instructions will be added as the project progresses past the boot sector stage.

Related Projects

Project	Description
MIPS	32-bit MIPS CPU design (Verilog, 5-stage pipeline, Harvard architecture)

License

This project is released into the public domain under the Unlicense.