Some people use the kernel and Operating system interchangeably. It is important to know what is the function of the kernel of an operating system.
While they both are different. A kernel is a centralized platform of an operating system that connects applications with the hardware and processes.
The kernel is an essential part of OS, and that is why the kernel has many functions.
Table of Contents
- What is Kernel in Operating System?
- What is the Function of the Kernel of an Operating System?
- Difference Between Kernel and OS
- Types of Kernel
What is Kernel in Operating System?
An operating system is system software that manages hardware and software resources and services for computer programs.
OS comprises different parts including memory, central processing unit (CPU), Arithmetic Logic Unit (ALU), Input/Output devices, storages devices, and peripheral devices. These components work in sync with each other.
The kernel is the core component of OS and system programs that is a collection of pieces that cannot be separated and run independently. It is the middle layer or bridge between hardware-level data processing and applications.
It converts the user commands into machine language. The kernel is a part of the OS that loads first and lives in the primary memory and loads in the memory’s protected area. It must be smaller. Smaller the kernel, the more efficient the system.
What is the Function of the Kernel of an Operating System?
The kernel is for providing an interface between hardware and application. It has several objectives including scheduling tasks, providing resources to the application or hardware, and handling system calls and interrupts.
The kernel performs creating, executing, and ending processes that are running in the system whenever a system is in an ON state (work). The process is the log file of the task that has all the information about the task that is present in the queue.
When a system has to execute any task, the kernel creates and manages the processes. It is an important task of the kernel as mismanagement of processes results in a deadlock.
Processes also communicate with each other, which is called inter-process management.
The kernel provides Inter-Process Communication methods for synchronization and communication between processes (IPC). IPC can take several forms, such as semaphore, shared memory, message queue, pipe (or called FIFO), and so on.
Once the kernel creates and executes the process for a task, it lives in memory and occupies space in it. When the process is ended, the kernel removes the process from the memory, and memory becomes reusable.
So, there must be someone who notifies or removes the ended task from the memory and the kernel plays this role.
It assigns the memory to process and releases it as well. Kernel monitors the allocation of the memory to the tasks and keeps a check on which part is available and can be allocated.
As kernel manages the connected devices, so it is also its responsibility to handle the exchange of data through these devices.
The information is received and sent through the system to the input/ output devices and different applications handled by the kernel.
Interrupt Handling and System Calls:
As mentioned in process management, the kernel manages process creation, execution, and termination.
When the process is running, there might come a task of top priority and need to be executed first. The kernel has to decide and perform the processes based on their priority.
The kernel also handles system calls. A system call is a software interrupt. As soon as it generates the system call, the kernel assigns the CPU and resources to that system call.
There are a few ways to call the respective kernel function: using a Software- Simulated Interrupt, a Gate Call, a Special System Call Instruction, and a Memory-based Queue, to name a few.
The kernel has control over memory, attached devices, and CPU processes and acts as and bridge between tasks (processes) and the resources. It allocates the storage memory and RAM to the processes according to their need.
If any process requires hardware, it also allocates hardware to it, and if any other task already booked that resource, then the new process is moved to a waiting list.
Scheduling of Processes:
The kernel implements different techniques to schedule different tasks in a multitasking system. It provides a slice of time to every process, starts process B when process A completes or is scheduled according to priority.
The resources and memory switch from process to process based on the scheduling algorithm kernel is using. It determines the state of the process, whether it is in running, waiting, or ended.
Difference Between Kernel and OS
- The operating system is a superset, while the kernel is its subset.
- Kernel acts as a bridge between applications and hardware, while OS is for the user and computer interaction.
- OS has three types: Single and multiprogramming batch system, Distributed operating system, and real-time operating system. The kernel has five types: monolithic, micro-kernel, Hybrid, Nano, and EXO kernel.
- The kernel handles the processes, tasks, memory, and disk. OS handles kernel and protection of the system.
Types of Kernel
There are five types of kernel. We have defined each type below:
Monolithic is a type of kernel in which all services of the operating system execute in kernel space. It is complex because of long and difficult code.
The system components have dependencies on synchronizing and work with each other. This kernel has better performance. The most common example of the monolithic kernel is Unix and Linux.
Micro-kernel follows the minimalist approach. It uses threads scheduling and virtual memory for processes.
It works reliably with fewer services in the kernel space, but it has many system calls and switches. Its stability is its biggest advantage. AmigaOS and Minix are the Micro-kernel examples.
The combination of monolithic and micro-kernel results in a hybrid kernel. It works frequently like a monolithic kernel and is stable like a micro-kernel.
It has advantages of both micro and monolithic kernel and is almost similar to the monolithic kernel. Windows NT and BeOS are examples.
This type of kernel tries to use very little hardware abstraction, and it is Exo kernel’s advantage. It works on the end-to-end principle. The Exo kernel allocates the physical resources to the application. EXOS is its example.
Nano kernel provides hardware abstraction and no system services like the micro-kernel. micro-kernel and Nano kernel are analogous to each other. EROS is its example.
By now you have good knowledge of what is the function of the kernel of an operating system. Every system needs an operating system as a system cannot run without OS and the same goes for the relationship of OS and kernel.
OS will work without a kernel. The kernel has many functions including scheduling, Input/output device management, and resource allocation.
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