MiniOS (Version 1.0)

MiniOS is a pedagogical operating system built as an advanced extension of the MIT xv6 UNIX-like teaching OS. It introduces modern operating system concepts including dynamic scheduling, advanced memory management, and specialized user space applications.

🚀 Core Features

MiniOS replaces standard xv6 components with advanced subsystems:

1. Dynamic Priority Scheduling: Preemptive scheduling algorithm featuring aging to prevent starvation. It dynamically adjusts process priorities based on CPU usage (applying a penalty for CPU-bound processes) and waiting time (applying an aging increment).

2. Copy-On-Write (COW) Fork: Optimized process creation where the parent and child share physical memory pages upon fork(). Pages are only duplicated when a process attempts to modify them, managed via a robust reference counting mechanism.

3. Advanced File Management System: Dynamic file storage handling creation, reading, writing, and deletion of files in dynamically allocated memory blocks.

4. Garbage Collection: Automatic memory reclamation subsystem that detects unused file blocks and cleans up memory during system idle periods to minimize performance impact.

5. Dynamic Memory Compaction: Eliminates external fragmentation caused by file deletions by reorganizing physical memory and updating internal file references dynamically.

6. Log Keeper: Robust logging mechanism (logkeeper) designed to reliably record system events, track operations, and assist in debugging and stress testing across the OS.

🛠⚙️ Environment & Tech Stack

• Target Architecture: RISC-V / x86 Architecture
• Emulator: QEMU
• Languages: C, Assembly
• Build Tools: GNU Toolchain (gcc, ld, make)

🏗️ Building and Running MiniOS

Ensure you have the required RISC-V or x86 toolchain installed, QEMU (e.g., qemu-system-riscv64 or qemu-system-i386), and Python 3.

1. Clone the repository and navigate to the project root.
2. Compile and run the OS using the custom runner script:

   python run_os.py

3. To view available commands once booted, explore the user space programs or refer to system binaries (e.g., help if implemented).

👥 Contributors

MiniOS Version 1.0 core subsystems were developed by:

• Taksh Mehta: Dynamic Priority Scheduling
• Aditya Sharma: Paging with Copy-On-Write (COW)
• Ved Mitra Verma: File Management System & Garbage Collection
• Mayank Tiwari: Dynamic Memory Compaction

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XV6 ACKNOWLEDGMENTS: xv6 is inspired by John Lions's Commentary on UNIX 6th Edition. MiniOS builds upon the foundational work provided by the MIT PDOS group.