Operating System Tutorial

What is Operating System Evolution of Operating System Types of Operating System Functions of Operating System What is Kernel and Types of Kernel Operating System Properties Operating System Services Components of Operating System Needs of the Operating System Linux Operating System Unix Operating System Ubuntu Operating System What is DOS Operating System Difference Between Multi-programming and Multitasking What is Thread and Types of Thread Process Management Process State What is Process Scheduler and Process Queue What is Context Switching What is CPU Scheduling Scheduling Algorithm FCFS (First-come-First-Serve) Scheduling SJF (Shortest Job First) Scheduling Round-Robin CPU Scheduling Priority Based Scheduling HRRN (Highest Response Ratio Next) Scheduling Process Synchronization Lock Variable Mechanism TSL Mechanism Turn Variable Mechanism Interested Variable Mechanism What is Producer-Consumer Problem What is Semaphore in Operating System Monitors in Operating System What is Deadlock Deadlock Avoidance Strategies for Handling Deadlock Deadlock Prevention Deadlock Detection and Recovery Resource Allocation Graph Banker’s Algorithm in Operating System Fixed Partitioning and Dynamic Partitioning Partitioning Algorithms What is Paging and Segmentation What is Demand Paging What is Virtual Memory Disk Scheduling Algorithms FCFS and SSTF Disk Scheduling Algorithm SCAN and C-SCAN Disk Scheduling Algorithm Look and C-Look Disk Scheduling Algorithm File in Operating System File Access Methods in Operating System File Allocation Method Directory Structure in Operating System Difference between C-LOOK and C-SCAN Difference between Rotational Latency and Disk Assess Time Trap vs Interrupt How to implement Monitors using Semaphores N-Step-SCAN Disk Scheduling Why is it critical for the Scheduler to distinguish between I/O-bound and CPU-bound programs Difference between C-SCAN and SSTF Difference between SCAN and FCFS Difference between Seek Time and Disk Access Time Difference between SSTF and LOOK

Kernel in OS

What is Kernel in OS?

The kernel is the core component in the operating system. The job of the kernel is to handle the communication between the hardware and the software. 

In other words, a kernel is defined as the computer program, which is like a heart or nucleus of the computer operating system along with full control over everything in the system. On most of the systems, a kernel is the first program that is loaded on start-up (after the boot-loader) and also controls the remaining other start-ups and requests of Input/output from software, converting them into the data-processing instructions for the CPU.

It manages peripherals devices such as Monitors, keyboards, speakers, and Printer. The kernel is the deepest part of the operating system.

The kernel handles the following:

  1. Resource management
  2. Device management
  3. Memory management
  4. CPU/GPU
  5. Input/output device
  6. System calls
  7. Memory

The processes of the user can access the space of the kernel with the help of system calls only. If a program wants to access the area of kernel directly, then it will result in a fault.

Features of Kernel

The features of the kernel are:

  • Inter-process communication
  • Context switching
  • Low-level scheduling of processes
  • Process synchronization

Types of Kernel

There are various types of the kernel:

  1. Microkernel
  2. Monolithic kernel
  3. Nano kernel
  4. Exo kernel
  5. Hybrid Kernel
What is Kernel

Monolithic Kernel: - In a monolithic kernel, the kernel and operating system, both run in the same memory, and it is mainly used where security is not a major concern. The result of the monolithic kernel is fastly accessible. But in some situations, like if a device driver has a bug, then there may be chances of a whole system crash.                    

Microkernel: - A Microkernel is the derived version of the monolithic kernel. In microkernel, the kernel itself can do different jobs, and there is no requirement of an additional GUI.

Nano kernel: - Nano kernel is the small type of kernel which is responsible for hardware abstraction, but without system services. Nano kernel is used in those cases where most of the functions are set up outside.

Exo kernel: - Exo kernel is responsible for resource handling and process protection. It is used where you are testing out an inhouse project, and in up-gradation to an efficient kernel type.

Hybrid kernel: - Hybrid kernel is a mixture of microkernel and monolithic kernel. The Hybrid kernel is mostly used in Windows, Apple’s macOS. Hybrid kernel moves out the driver and keeps the services of a system inside the kernel.