PS2 Command Core OS (asmos)

A next-gen custom operating layer for the PlayStation 2: CLI power interface, advanced memory management, and network/party features. Built as a NASM real-mode boot chain + x86 assembly kernel glue + C kernel, with a platform HAL multiplexed for PS2 EE (FreeMCBoot) and x86 QEMU/modchip CD targets.

PS2 Compatibility

This OS is designed to run on PlayStation 2 consoles with the following specifications:

• CPU: MIPS R5900 (Emotion Engine) - x86 emulation via modchip
• Memory: 32MB DDR SDRAM
• Storage: CD/DVD Drive
• Controllers: DualShock 2 Support
• Network: Ethernet (optional)

Requirements

Hardware Requirements

• PS2 Console (any model)
• DMS3 Modchip (or any compatible modchip)
• CD/DVD Media for burning the OS
• USB Keyboard (for shell interaction)

Software Requirements

• Linux Terminal (Ubuntu/Debian recommended)
• NASM (Netwide Assembler) for Assembly compilation
• GCC (GNU Compiler Collection) for C compilation
• i686-elf-gcc cross-compiler
• i686-elf-binutils for linking
• mkisofs for ISO creation
• growisofs for CD burning

Quick Start

1. Install Dependencies

# One-command setup (x86 tools, QEMU, Docker/PS2SDK, verify build)
./setup.sh

# Or manually on Ubuntu/Debian:
sudo apt-get update
sudo apt-get install nasm gcc-multilib make dosfstools genisoimage qemu-system-x86

2. Build the OS

# Clone the repository
git clone <repository-url>
cd asmOS

# Build for PS2 (optimized)
make ps2-build

# Or build with debugging
make all

3. Create Bootable CD

# Create ISO image
make iso

# Burn to CD (replace /dev/sr0 with your CD drive)
growisofs -dvd-compat -Z /dev/sr0=ps2os.iso

4. Boot on PS2

1. Insert the burned CD into your PS2
2. Power on the PS2 with modchip enabled
3. The OS will boot automatically
4. Use keyboard to interact with the shell

Build Options

Available Make Targets

• make all - Standard build
• make ps2-build - PS2-optimized build
• make ps2-test - Test PS2 build in QEMU
• make iso - Create bootable ISO
• make setup / ./setup.sh - Install all deps and verify environment
• make test-integration - Build + symbol/stub checks
• make ps2-native - Build PS2 EE ELF for FreeMCBoot
• make fmcb-package - Assemble FreeMCBoot deploy folder
• make clean - Clean build artifacts
• make info - Show build information

v3.0 Architecture

• NASM boot (boot/stage1.asm, fatload16.asm) — real-mode FAT12 kernel load, E801 RAM probe → 0x500, PM jump to 0x100000
• NASM kernel glue (boot/arch_x86/) — ATA disk I/O, keyboard/VGA text, timer, speaker, syscalls (syscalls_x86.asm), context switch
• FAT12 chain — disk_read_sector → fat12_read_sector → plat_fs_* → shell ls / fat12_list_files
• C kernel (src/, platform/x86/) — shell, scheduler policy, memory, net, subsystems
• Platform HAL (include/platform.h, platform/x86/, platform/ps2/) — shared logic, target-specific backends
• QEMU — make run attaches disk/os.img as IDE (if=ide); protected-mode ATA PIO matches disk_io.asm
• Note: boot/stage2.c is an alternate C FAT loader; live x86 boot uses NASM stage1 only
• Network stack (src/net/, src/net_clients.c) — UDP transport, ping, FTP/telnet/IRC clients
• FAT12 I/O — read/write/delete via platform storage layer
• FreeMCBoot — scripts/build_fmcb_package.sh, docs/HARDWARE_TESTING.md

PS2-Specific Optimizations

• CPU: Optimized for Pentium III era (PS2 x86 emulation)
• Memory: 32MB RAM allocation
• Graphics: VGA text mode compatibility
• Storage: FAT12 filesystem for CD compatibility

Features

Enhanced Bootloader

• PS2 hardware detection
• Enhanced error handling
• Larger kernel support (16KB)
• Improved disk I/O

Advanced Kernel

• PS2-specific optimizations
• Enhanced memory management
• Improved task scheduling
• Better system information display

Rich Shell Environment

• ps2info - PS2 hardware information
• meminfo - Memory usage details
• ls - File listing with sizes
• clear - Screen clearing
• reboot - System restart
• help - Command help system

Filesystem Support

• FAT12 filesystem for CD compatibility
• File listing with detailed information
• Directory navigation (planned)
• File reading capabilities (planned)

System Commands

Basic Commands

help          # Show available commands
ls            # List files
clear         # Clear screen
echo <text>   # Echo text
exit          # Exit shell

System Information

ps2info       # PS2 hardware information
meminfo       # Memory usage information
date          # Current date/time

System Control

reboot        # Reboot system

Debugging

QEMU Testing

# Test in QEMU before burning to CD
make ps2-test

# Debug with GDB
make debug
# In another terminal: make gdb

Common Issues

1. CD not booting: Ensure modchip is properly installed
2. Build errors: Check cross-compiler installation
3. Memory issues: Verify 32MB RAM allocation
4. Keyboard not working: Check USB keyboard compatibility

Advanced Configuration

Customizing for Different PS2 Models

Edit boot/boot.asm to adjust:

• Memory detection thresholds
• Hardware compatibility flags
• Boot messages

Adding New Commands

Edit src/shell.c to add:

• New command functions
• Command descriptions
• Help text

Optimizing Performance

Edit Makefile to adjust:

• Compiler optimization flags
• CPU architecture settings
• Memory allocation

Technical Details

Boot Process

1. BIOS Load: PS2 BIOS loads bootloader from CD
2. Hardware Detection: Detect PS2-specific hardware
3. Kernel Load: Load kernel from FAT12 filesystem
4. System Init: Initialize memory, scheduler, shell
5. User Interface: Present enhanced shell to user

Memory Layout

• 0x0000-0x7BFF: Bootloader
• 0x7C00-0x7DFF: Boot sector
• 0x10000-0x1FFFF: Kernel (16KB)
• 0x20000+: User space and system data

Filesystem

• FAT12: Compatible with CD media
• Boot Sector: Enhanced with PS2 branding
• Root Directory: 224 entries maximum
• File Size: Up to 32MB per file

License

This project is licensed under the MIT License - see the LICENSE file for details.