ModuOS

ModuOS is a hobby operating system written in C and x86-64 assembly, designed for learning and experimentation. It features a custom kernel with interrupt handling, memory management (paging, physical memory allocator), multitasking with process management, and support for multiple file systems (FAT32, ISO9660).

✨ Features

• Custom 64-bit Kernel: Long mode x86-64 kernel with Multiboot2 support
• Memory Management: Physical memory allocator, virtual memory with paging, kernel heap
• Process Management: Multitasking, context switching, ELF executable loading, syscall interface
• Drivers:
  • Storage: ATA/ATAPI, AHCI/SATA support
  • Graphics: VBE text mode
  • Input: PS/2 keyboard and mouse
  • System: PCI enumeration, ACPI, RTC, PIC/Timer
• File Systems: FAT32 and ISO9660 (read-only) with virtual file system layer
• Userland: Basic applications and games (cat, echo, shell, games)
• Built-in Games: Raycaster FPS, Snake (Eat Fruit), Stack Blocks, Vertical Ping Pong, Mine Sweeper

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📋 Requirements

Build Environment

• Docker Desktop - For cross-compilation environment
• QEMU - For testing and running the OS
• Windows - Primary tested platform (Linux/macOS may work with modifications)

Optional

• Visual Studio Code or any code editor for development
• Git for version control

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🚀 Quick Start

1. Clone the Repository

git clone https://github.com/NtinosTheGamer2324/ModuOS.git
cd ModuOS

2. Build the Docker Build Environment

The project uses a Docker container with a cross-compiler toolchain. Build the image:

docker build buildenv -t modu-os

This creates a modu-os image containing:

• x86_64-elf-gcc cross-compiler
• NASM assembler
• GRUB bootloader tools
• xorriso for ISO creation

3. Create a Disk Image

ModuOS requires a 1GB FAT32-formatted disk image named disk.img in the project root.

Option A: Using PowerShell (Windows)

# Create 1GB file
fsutil file createnew disk.img 1073741824

# Use Disk Management or diskpart to format as FAT32

Option B: Using third-party tools

• Win32 Disk Imager
• Rufus (create a FAT32 formatted file)

⚠️ Important: The build script does not create disk.img automatically. You must provide it.

4. Build and Run

Simply run the batch script:

run.bat

This will:

1. ✅ Check if Docker is running (and start it if needed)
2. 🔨 Build the kernel inside the Docker container
3. 📦 Create a bootable ISO with GRUB2
4. 🚀 Launch QEMU with the ISO and disk image
5. 📄 Open log viewer for com1.log and com2.log

5. Log Viewer Setup (Optional)

To view COM port logs during runtime:

1. Download Log Viewer v1
2. Place it at: vendor/NTSoftware/Log Viewer.exe
3. The run.bat script will automatically open it

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📁 Project Structure

ModuOS/
├── buildenv/           # Docker build environment configuration
├── include/            # Header files
│   └── moduos/         # Kernel, driver, and filesystem headers
│       ├── arch/       # Architecture-specific (AMD64)
│       ├── drivers/    # Hardware driver headers
│       ├── fs/         # File system headers
│       └── kernel/     # Kernel subsystem headers
├── src/                # Source code
│   ├── arch/AMD64/     # x86-64 specific code (boot, interrupts, syscalls)
│   ├── drivers/        # Hardware drivers (ATA, AHCI, VGA, PCI, etc.)
│   ├── fs/             # File system implementations
│   └── kernel/         # Core kernel (memory, process, scheduler, etc.)
├── targets/AMD64/      # Build target configuration
│   ├── iso/            # ISO layout for bootable image
│   └── linker.ld       # Linker script
├── userland/           # User-space programs
├── LICENSES/           # Third-party licenses
├── Makefile            # Build system
├── run.bat             # Build and test script
└── LICENSE             # Project license (GPLv2)

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🛠️ Manual Build Steps

If you prefer to build manually without run.bat:

# Build the kernel
docker run --rm -it -v "%cd%":/root/env modu-os make clean build-AMD64

# Run in QEMU
qemu-system-x86_64 ^
    -M pc-i440fx-6.2 ^
    -m 1024M ^
    -smp 2 ^
    -serial file:com1.log ^
    -serial file:com2.log ^
    -drive file=dist/AMD64/kernel.iso,format=raw,media=cdrom ^
    -drive id=disk,file=disk.img,if=none,format=raw ^
    -device ahci,id=ahci ^
    -device ide-hd,drive=disk,bus=ahci.0 ^
    -boot d

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🎮 Available Applications & Games

Once booted, you can run:

Applications

• cat <file> - Display file contents
• echo <text> - Print text to console
• sh - Simple shell
• memtest - Memory testing utility
• neofetch - System information display

Games

• Raycaster FPS - First-person perspective game
• Eat Fruit (Snake) - Classic snake game
• Stack Blocks - Block stacking puzzle
• Vertical Ping Pong - Pong variant
• Mine Sweeper - Minesweeper clone

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🧪 Development

Building Userland Programs

cd userland
./build.sh  # Linux/WSL

User programs are compiled separately and placed in targets/AMD64/iso/Apps/.

Debugging

• Serial Output: Kernel outputs debug information to COM1 and COM2 ports
• QEMU Monitor: Press Ctrl+Alt+2 in QEMU to access the monitor
• GDB Debugging: Add -s -S to QEMU args and connect with gdb

qemu-system-x86_64 -cdrom dist/AMD64/kernel.iso -s -S &
gdb dist/AMD64/mdsys.sqr
(gdb) target remote localhost:1234
(gdb) continue

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🤝 Contributing

Contributions are welcome! Here's how you can help:

1. 🍴 Fork the repository
2. 🌿 Create a feature branch (git checkout -b feature/amazing-feature)
3. 💾 Commit your changes (git commit -m 'Add amazing feature')
4. 📤 Push to the branch (git push origin feature/amazing-feature)
5. 🔃 Open a Pull Request

Contribution Guidelines

• Follow existing code style and conventions
• Comment your code where necessary
• Test your changes in QEMU before submitting
• Update documentation if you add new features

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📄 License

This project is licensed under the GNU General Public License v2.0 only - see the LICENSE file for details.

Third-Party Components

ModuOS uses several third-party components:

• GRUB2 - Bootloader (GPLv3+)
• Multiboot2 - Boot protocol specification
• GCC Cross-Compiler - Build toolchain (GPLv3+)

See the LICENSES folder for full license texts of third-party components.

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🙏 Acknowledgments

• OSDev Community - Invaluable resources at wiki.osdev.org
• Multiboot2 Specification - Boot protocol by GNU GRUB
• randomdude/gcc-cross-x86_64-elf - Docker base image for cross-compilation

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📞 Contact & Links

• Project Repository: github.com/NtinosTheGamer2324/ModuOS
• Issues & Bug Reports: GitHub Issues
• Developer: New Technologies Software

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Made with ❤️ for learning and fun