🌌 TilekarOS

TilekarOS is a hobbyist, 32-bit monolithic operating system built from scratch for the x86 (i386) architecture. Written primarily in C and Assembly, it serves as a platform for exploring kernel development, low-level hardware interfacing, and operating system design principles.

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✨ Key Features

• 🛡️ x86 Protected Mode: Operates in 32-bit Protected Mode with custom GDT and IDT.
• 🔄 Multitasking & ELF: Preemptive multitasking with a round-robin scheduler and ELF32 executable loading.
• 📁 Storage & Filesystem:
  • VFS (Virtual File System): Abstracted file operations (open, read, write, mkdir).
  • FAT12: Native File Allocation Table implementation with read/write support.
  • Buffer Cache: Sector-level caching to accelerate disk I/O.
• 🔌 Hardware Drivers:
  • ATA (IDE): Support for hard disks using PIO and high-speed DMA modes.
  • PCI Bus: Automatic hardware discovery, enumeration, and Bus Master configuration.
  • PS/2 Keyboard & VGA TTY: Fully interactive console and input system.
• 🛠️ System Calls: Robust API (via int 0x80) for user-space interaction.
• 📦 Custom LibC: Minimal C standard library (stdio, string, stdlib).

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🏗️ Project Structure

.
├── kernel/                 # Kernel source code
├── libc/                   # Minimal C library implementation
├── sysroot/                # Generated userspace development environment
├── VirtualMachine/         # Default workspace for disk images and logs
├── cmake/toolchains/       # Cross-compilation configuration
└── Makefile                # Powerful master build & emulation control

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🚀 Quick Start

🧰 Prerequisites

Ensure you have the following tools installed: Clang, LLD, NASM, CMake, Make, QEMU, grub-common, xorriso, mtools.

🛠️ Build and Run

TilekarOS features a Dynamic Workspace System that manages isolated disk images and files.

# 1. Build kernel and populate development sysroot
make

# 2. Run in Kernel Mode (Fastest for kernel development)
make run DRIVES=boot:32:ahci

# 3. Run in Disk Mode (Realistic GRUB boot from a hard disk)
make run_disk DRIVES=boot:32:ide

# 4. Clean build artifacts
make clean

For a full list of commands and advanced configuration, run:

make help

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💻 Userspace Development

TilekarOS supports a full userspace development environment via a Sysroot.

📦 The Sysroot

When you build the project, a sysroot/ directory is automatically populated with:

• Headers: LibC and Kernel API headers in sysroot/usr/include.
• Libraries: libc.a static library in sysroot/usr/lib.
• Startup: crt0.o (entry point) and user.ld (linker script) in sysroot/usr/lib.

🛠️ Compiling Applications

You can compile your own C programs into OS-compatible binaries using the built-in helper:

# Compile a source file into an executable
make comp_exe FILE=./my_app.c OUT=./my_app

This uses the sysroot automatically to link against the correct standard library and headers for TilekarOS.

💿 Workspace & Persistence

TilekarOS manages disk images via Workspaces (Default: VirtualMachine).

1. Automatic Integration: Any .c file placed in your workspace root is automatically copied to the boot drive root.
2. Persistence: Files written by the OS to its disks are automatically exported to $(VM)/exported_drives/ when you exit QEMU.
3. Two-Way Sync: If you place files in $(VM)/exported_drives/boot/, they will be present on the OS disk at the next launch.

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📚 Documentation

Comprehensive technical documentation is available at: 👉 sohamtilekar.github.io/TilekarOS/

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📜 License

Distributed under the MIT License. See LICENSE for more information.