Kernel

What is Kernel?

Kernel is the very essential central core part of the operating system which has complete control over everything that happen in the system. it provides basic service to all part of the operating system. It acts as a bridge between the Application and data processing at the Hardware level.It loads the data to the memory and runs after the BIOSGenerally it is stored to the protected memory space, which prevents it from being overwritten from other.

Generally it includes,

1) A Scheduler:It determines how the various processes share the processing time of the Kernel

2) A Supervisor:It gives use of the computer to each process when it is scheduled.

3) An Interrupt Handler;It handles all the interrupt requested from all the hardware devices.

4) A Memory Manager:It allocates memory.

Types of Kernel

There are four popular categories or kinds of Kernels namely monolithic kernels, microkernels, hybrid kernels and exokernels.

1)Monolithic Kernel:Monolithis Kernels are the part of Unix like operating system like Linux,FreeBSD etc. These types of kernel consists of the core part of the operating system and device driver with the ability to load the modules at the run-time.

2)Micro kernel:Microkernel are the part of the operating system like BeOS, Mac OS X, MINIX, QNX etc. These types of kernel generally provide only the minimal service such as defining memory address space, Inter-Process Communication (IPC) and memory management. Running the hardware process are not handled directly by Microkernel.

3)Hybrid Kernel:Hybrid Kernel it the part of the operating system like Microsoft Windows NT, 2000,XP etc. These types of kernel are the extension of the microkernel with some properties of monolithic kernel. These types of kernel are unable to load module during the run time.

4)Exokernel:Exokernel are evolving and still on experiment. It can corporate with multiple operating system library, that means it can handle more than one operating system at a same time, like we can use both windows and linux operating system at same time.