# Exploring Operating Systems: 69 Days of Deep Dive Implementation in C

## Overview
This repository is a journey through Operating System concepts, with practical implementations in C. Each day focuses on a specific topic, providing theoretical understanding and hands-on coding experience.

## Repository Structure
- Each topic will have its own directory
- Includes source code, explanations, and implementation details
- Progressive learning path from basic to advanced OS concepts

## 69 Days Exploration Roadmap

| Day | Topic | Concept Category | Difficulty Level | Implementation Focus |
|-----|-------|------------------|------------------|----------------------|
| 1   | Process Concept | Processes | Easy | Process Definition |
| 2   | Process States and Transitions | Processes | Medium | State Diagram Implementation |
| 3   | Process Creation Mechanisms | Processes | Medium | Fork(), Exec() Syscalls |
| 4   | Process Scheduling Basics | Scheduling | Medium | FCFS Algorithm |
| 5   | Scheduling Algorithms | Scheduling | Hard | SJF, Priority, Round Robin |
| 6   | Context Switching | Processes | Hard | Implementation Details |
| 7   | Thread Concept | Threads | Easy | Thread Basic Understanding |
| 8   | Thread Creation and Management | Threads | Medium | POSIX Threads |
| 9   | Thread vs Process Comparison | Threads | Medium | Comparative Analysis |
| 10  | Multithreading Models | Threads | Hard | User vs Kernel Threads |
| 11  | Concurrency Fundamentals | Synchronization | Medium | Race Conditions |
| 12  | Mutex and Semaphores | Synchronization | Hard | Implementation |
| 13  | Deadlock Concepts | Synchronization | Hard | Prevention Strategies |
| 14  | Deadlock Detection Algorithms | Synchronization | Hard | Banker's Algorithm |
| 15  | Memory Management Overview | Memory | Easy | Memory Hierarchy |
| 16  | Logical vs Physical Address | Memory | Medium | Address Translation |
| 17  | Contiguous Memory Allocation | Memory | Medium | Allocation Strategies |
| 18  | Paging Mechanism | Memory | Hard | Page Table Implementation |
| 19  | Page Replacement Algorithms | Memory | Hard | FIFO, LRU, Optimal |
| 20  | Segmentation | Memory | Medium | Segment Table |
| 21  | Virtual Memory Concepts | Memory | Hard | Demand Paging |
| 22  | Memory Allocation Internals (malloc, free) | Memory Management | Hard | Custom Memory Allocator |
| 23  | Dynamic Memory Management Techniques | Memory Management | Hard | Memory Pool Strategies |
| 24  | File System Basics | File Systems | Easy | File Concept |
| 25  | File System Structure | File Systems | Medium | Directory Structures |
| 26  | File Allocation Methods | File Systems | Medium | Contiguous, Linked |
| 27  | Free Space Management | File Systems | Hard | Bit Vector, Linked List |
| 28  | File Protection Mechanisms | File Systems | Medium | Access Control |
| 29  | I/O System Management | I/O Systems | Medium | I/O Devices |
| 30  | Disk Scheduling Algorithms | I/O Systems | Hard | SCAN, C-SCAN |
| 31  | Interrupt Handling | Low-Level | Hard | Interrupt Vectors |
| 32  | Advanced System Call Implementation | Low-Level Programming | Hard | Syscall Wrapper Design |
| 33  | Advanced System Call Tracing | Low-Level | Hard | Syscall Interception |
| 34  | Kernel Module Development | Low-Level | Hard | Loadable Kernel Modules |
| 35  | Inter-Process Communication | IPC | Hard | Pipes, Message Queues |
| 36  | Shared Memory Advanced | IPC | Hard | Low-Level Shared Memory |
| 37  | Socket Programming Deep Dive | Networking | Hard | Raw Socket Implementation |
| 38  | CPU Scheduling Advanced | Scheduling | Hard | Multi-Level Queues |
| 39  | Real-Time Operating Systems Internals | Specialized | Hard | RTOS Kernel Design |
| 40  | Linux Kernel Memory Management | Kernel | Hard | Slab Allocator |
| 41  | Process Synchronization Advanced | Synchronization | Hard | Peterson's Algorithm |
| 42  | Resource Allocation Graph Theory | Synchronization | Hard | Deadlock Representation |
| 43  | Memory Fragmentation Techniques | Memory | Medium | Advanced Fragmentation |
| 44  | Cache Management Internals | Memory | Hard | Cache Coherence |
| 45  | File System Journaling | File Systems | Hard | Transaction Mechanisms |
| 46  | Device Driver Development | Low-Level | Hard | Character Device Drivers |
| 47  | Security Mechanism Implementation | Security | Hard | Access Control Kernel |
| 48  | Process Scheduling Simulator | Scheduling | Hard | Comprehensive Simulator |
| 49  | Network File Systems Internals | File Systems | Hard | Distributed FS Design |
| 50  | Error Handling Kernel Mechanisms | Low-Level | Hard | Exception Management |
| 51  | Virtual Memory Hypervisor | Advanced | Hard | Virtualization Techniques |
| 52  | Distributed OS Algorithms | Advanced | Hard | Consensus Protocols |
| 53  | Embedded OS Kernel Design | Specialized | Hard | Minimal Kernel |
| 54  | Microkernel Advanced Design | Architecture | Hard | Message Passing |
| 55  | OS Performance Profiling | Advanced | Hard | Kernel Tracing |
| 56  | Parallel Processing Primitives | Advanced | Hard | Low-Level Parallelism |
| 57  | Fault Tolerance Mechanisms | Advanced | Hard | Recovery Techniques |
| 58  | Advanced Load Balancing | Advanced | Hard | Scheduling Strategies |
| 59  | Containerization Internals | Advanced | Hard | Namespace Implementation |
| 60  | Kernel Synchronization Primitives | Advanced | Hard | Spinlocks, RCU |
| 61  | Security Vulnerability Analysis | Security | Hard | Buffer Overflow |
| 62  | Cryptographic Kernel Mechanisms | Security | Hard | Encryption Primitives |
| 63  | Malware Detection Techniques | Security | Hard | Kernel-Level Detection |
| 64  | OS Forensics Deep Dive | Security | Hard | Kernel Trace Analysis |
| 65  | Memory Allocator Design | Memory | Hard | Custom Heap Implementation |
| 66  | Advanced IPC Mechanisms | IPC | Hard | Advanced Signaling |
| 67  | Kernel Debugging Techniques | Low-Level | Hard | Kernel Crash Analysis |
| 68  | Advanced Syscall Handling | Low-Level | Hard | Syscall Optimization |
| 69  | Complete OS Kernel Prototype | Project | Hard | Minimal Bootable Kernel |

---

## Final Projects
Each project spans 3 days, allowing for in-depth exploration and implementation.

1. **Build a Minimal Bootable Kernel**  
   - Create a simple kernel that boots and prints a message to the screen.

2. **Implement a Custom Memory Allocator**  
   - Design and implement a memory allocator with malloc, free, and realloc functionality.

3. **Develop a File System Simulator**  
   - Simulate a basic file system with directory structures, file allocation, and free space management.

4. **Create a Process Scheduling Simulator**  
   - Implement a simulator for various scheduling algorithms like FCFS, SJF, and Round Robin.

5. **Design a Virtual Memory Manager**  
   - Build a virtual memory manager with paging and page replacement algorithms.

6. **Develop a Loadable Kernel Module**  
   - Write a kernel module that interacts with the Linux kernel and performs a specific task.

7. **Implement a Network File System**  
   - Create a basic distributed file system with client-server communication.

8. **Build a Real-Time Operating System Kernel**  
   - Design a minimal RTOS kernel with task scheduling and synchronization primitives.
  
## Contributing
- Detailed code implementations welcome
- Follow coding standards
- Include comprehensive documentation

## Learning Objectives
- Deep understanding of Operating System principles
- Practical C programming skills
- Real-world problem-solving techniques

## Prerequisites
- C Programming
- Deep Computer Science Knowledge
- Linux/Unix Kernel Understanding Recommended

## License
[LICENSE](LICENSE)

## Disclaimer
This is an advanced educational resource for understanding Operating Systems through in-depth implementation.
