ToyOS

A minimal operating system kernel demonstrating multi-language systems programming.

Features

• Multi-language integration: Assembly, C, Rust, and C++
• Protected mode with GDT and IDT
• Interrupt handling: Full ISR and IRQ support with PIC remapping
• Memory management: Rust page allocator, kernel heap, virtual memory
• Device drivers: Keyboard, timer, VGA terminal, serial port
• Interactive shell: CLI with built-in commands
• Task management: Basic multitasking with context switching
• Power management: ACPI shutdown and reboot
• VGA cursor control

Architecture

The kernel consists of four language layers working together:

• Assembly: Multiboot bootloader and hardware initialization
• C: Core kernel functionality and VGA terminal driver
• Rust: Memory management with page frame allocator
• C++: Device driver layer with OOP abstractions

Building

Prerequisites:

• NASM assembler
• GCC/G++ with 32-bit multilib support
• Rust toolchain (install i686-unknown-linux-gnu target)
• GNU ld linker
• QEMU for testing

Install Rust target:

rustup target add i686-unknown-linux-gnu

Build the kernel:

./build.sh

Run in QEMU:

./run.sh

Or use Make:

make
make run

Project Structure

boot/           Multiboot bootloader (Assembly)
kernel/         Core kernel (C)
driver/         Device drivers (C++)
rust_module/    Memory manager (Rust)
docs/           Technical documentation

Documentation

See the docs/ directory for detailed technical information:

• Boot process and initialization
• Memory layout and allocation
• Build system and linking
• API reference
• ABI compatibility

Learning Objectives

This project demonstrates:

• x86 protected mode programming
• Cross-language linking and FFI
• Freestanding code without standard libraries
• Memory management fundamentals
• VGA text mode driver implementation

License

Educational use. Modify freely for learning purposes.

Resources

• OSDev Wiki: https://wiki.osdev.org
• Intel x86 manuals
• System V i386 ABI specification