Operating System Roadmap

অপারেটিং সিস্টেম (OS) হলো কম্পিউটারের হার্ডওয়্যার এবং ইউজারের মধ্যে একটি ইন্টারফেস। একজন সফটওয়্যার ইঞ্জিনিয়ার হিসেবে OS-এর ইন্টারনাল মেকানিজম জানা অত্যন্ত জরুরি।

Foundations

1. Operating System Foundations
   • What is an Operating System
   • System Calls & APIs
   • Boot Process
   • History & Types of OS
   • Kernel vs User Space

Processes & Threads

1. Processes & Threads
   • Process States & Lifecycle
   • Context Switching
   • Inter-Process Communication
   • Processes & PCB
   • Threads vs Processes
   • Scheduling Algorithms

Concurrency & Synchronization

1. Concurrency & Synchronization
   • Race Conditions
   • Locks & Semaphores
   • Deadlocks
   • Critical Sections
   • Monitors & Condition Variables

Memory Management

1. Memory Management
   • Physical & Virtual Memory
   • Paging & Segmentation
   • Page Replacement Algorithms
   • Thrashing
   • Memory Allocation
   • MMU

File Systems & Storage

1. File Systems & Storage
   • File System Structure
   • File Concepts
   • Directory Implementation
   • Inodes
   • Journaling File Systems
   • Disk Scheduling Algorithms

I/O & Device Management

1. I/O & Device Management
   • I/O System Overview
   • Interrupts
   • Device Drivers
   • DMA (Direct Memory Access)
   • Buffering & Caching

Security & Protection

1. Security & Protection
   • User Authentication
   • Capabilities
   • Sandboxing & Isolation
   • Access Control Lists
   • Encryption in OS

Distributed OS Concepts

1. Distributed OS Concepts
   • Client-Server Model
   • Distributed File Systems
   • Consensus (Paxos, Raft)
   • Process Migration
   • Clock Synchronization

Advanced Topics

1. Advanced Topics
   • Virtualization & Hypervisors
   • NUMA
   • Modern OS Internals
   • Containers vs VMs
   • Real-Time Operating Systems

Projects

1. Write a Simple Shell

   • Command reading and parsing
   • Process creation with fork()
   • Command execution with exec()
   • Built-in commands

2. Implement a Virtual Memory Manager

   • Virtual to physical address translation
   • TLB simulation
   • Page table management
   • Page replacement algorithms

3. Mini OS Kernel (Educational)

   • Bootloader development
   • Kernel initialization
   • VGA text mode driver
   • Keyboard driver and interrupts

4. Build a Process Scheduler Simulator

   • FCFS, SJF, Round Robin implementation
   • Gantt chart visualization
   • Waiting time & Turnaround time calculation

5. File System Simulation Project

   • Virtual disk creation with Superblock & Inodes
   • File operations (Create, Read, Write, Delete)
   • Directory structure & bitmap management

Interview Preparation

1. OS Fundamentals Q&A

   • Theoretical Questions (Process, Thread, Deadlock, Memory)

   • Scenario-based Questions (Debugging, System Design)

   • Real-world OS internal questions (Chrome, Nginx, DB)

2. Processes & Threads Q&A

   • PCB, Process States, Scheduler Types
   • User vs Kernel Threads, Fork/Exec detailed
   • Zombie/Orphan Processes, Context Switching Analysis

3. Deadlocks & Synchronization Q&A

   • Banker's Algorithm, Spinlock vs Mutex

   • Dining Philosophers, Readers-Writers Problems

   • Priority Inversion (Mars Pathfinder), Deadlock Recovery

4. File System & Disk Q&A

   • Inodes, Hard vs Soft Links, Journaling
   • RAID Levels, Disk Scheduling Algorithms
   • Scenario: Deleting open files, SSD vs HDD I/O