Skip to main content

Micro kernel architecture

 Micro kernel architecture

What is Kernel?

A kernel is an important part of an OS that manages system resources. It also acts as a bridge between the software and hardware of the computer. It is one of the first program which is loaded on start-up after the bootloader. The Kernel is also responsible for offering secure access to the machine's hardware for various programs. It also decides when and how long a certain application uses specific hardware.

What is Microkernel?

Microkernel is a software or code which contains the required minimum amount of functions, data, and features to implement an operating system. It provides a minimal number of mechanisms, which is good enough to run the most basic functions of an operating system. It allows other parts of the operating system to be implemented as it does not impose a lot of policies.

Microkernels and their user environments are usually implemented in the C++ or C programming languages with a little bit of assembly. However, other implementation languages are possible with some high-level coding.

What is a Monolithic Kernel?

Monolithic Kernel runs all the basic system services like process management, Memory management, I/O communication, and interrupt handling, file system, etc in kernel space.

In this type of Kernel approach, the entire operating system runs as a single program in kernel mode. The operating system is written as a collection of procedures that are linked together into a large executable binary program.

1. Monolithic architecture

2.    Layerd archtecture.

3.     Virtual machine architecture

4.     Exokernel architecture

5.    Client server architecture 

6.     Micro kernel architecture

Microkernel Architecture

A Microkernel is the most important part for correct implementation of an operating system. You can see in the below-given diagram, that Microkernel fulfills basic operations like memory, process scheduling mechanisms, and inter-process communication.

Microkernel Based Operating System

Microkernel is the only software executing at the privileged level. The other important functionalities of the OS are removed from the kernel-mode and run in the user mode. These functionalities may be device drivers, application, file servers, interprocess communication, etc.

Components of Microkernel

A microkernel comprises only the core functionalities of the system. A component is included in the Microkernel only if putting it outside would interrupt the functionality of the system. All other non-essential components should be put in the user mode.

The minimum functionalities required in the Microkernel are:

  • Memory management mechanisms like address spaces should be included in the Microkernel. It also contains memory protection features.
  • Processor scheduling mechanisms should contain process and thread schedulers.
  • Inter-process communication manages the servers that run their own address spaces.

Difference Between Microkernel and Monolithic Kernel

ParametersMonolithic kernelMicroKernel
BasicIt is a large process running in a single address spaceIt can be broken down into separate processes called servers.
CodeIn order to write a monolithic kernel, less code is required.In order to write a microkernel, more code is required
SecurityIf a service crashes, the whole system collapses in a monolithic kernel.If a service crashes, it never affects the working of a microkernel.
CommunicationIt is a single static binary fileServers communicate through IPC.
ExampleLinux, BSDs, Microsoft Windows (95,98, Me), Solaris, OS-9, AIX, DOS, XTS-400, etc.L4Linux, QNX, SymbianK42, Mac OS X, Integrity, etc.

Advantages of Microkernel

Here, are the pros/benefits of using Microkernel

  • Microkernel architecture is small and isolated therefore it can function better.
  • Microkernels are secure because only those components are included that disrupt the functionality of the system otherwise.
  • The expansion of the system is more accessible, so it can be added to the system application without disturbing the Kernel.
  • Microkernels are modular, and the different modules can be replaced, reloaded, modified without even touching the Kernel.
  • Fewer system crashes when compared with monolithic systems.
  • Microkernel interface helps you to enforce a more modular system structure.
  • Without recompiling, add new features
  • Server malfunction is also isolated as any other user program's malfunction.
  • Microkernel system is flexible, so different strategies and APIs, implemented by different servers, which can coexist in the system.
  • Increased security and stability will result in a decreased amount of code which runs on kernel mode

Disadvantage of Microkernel

Here, are drawback/cons of using Microkernel:

  • Providing services in a microkernel system are expensive compared to the normal monolithic system.
  • Context switch or a function call needed when the drivers are implemented as procedures or processes, respectively.
  • The performance of a microkernel system can be indifferent and may lead to some problems.

Summary:

  • A kernel is an important part of an OS that manages system resources.
  • A microkernel is a software or code which contains the required minimum amount of functions, data, and features to implement an operating system.
  • In Monolithic Kernel approach, the entire operating system runs as a single program in kernel mode
  • A Microkernel is the most important part for correct implementation of an operating system.
  • A microkernel comprises only the core functionalities of the system.
  • A monolithic kernel is a large process running in a single address space, whereas Microkernel can be broken down into separate processes called servers.
  • Microkernel architecture is small and isolated therefore it can function better
  • Providing services in a microkernel system are expensive compared to the normal monolithic system.

Comments

Post a Comment

Popular posts from this blog

OS its Resource Manager and its Function

  Operating system as resource manager:   ·           A computer system usually has many hardware and software resources such as processor , memory, disk printer, I/O devices etc. ·           The task of resources management becomes essential in multi-user operating system where different user compute for the same resource.   Operating system manages resources in two ways : 1.         Time multiplexing : it defines the sharing of resources on the basis of fixed time slices. For example, the operating system allocate the resources, such as CPUto program A for fixed time slice. 2.         Space timing:  it defines the concurrent sharing of resources among different programs.for example, sharing of hard disk and main memory is space multiplexing.     FUNCTION OF OPERATING SYSTEM     The primar...
2 comments
Read more

Suspend a process

  Suspend a process A process is an active program. It can also be said as a program that is under execution. It is more than the program code as it includes the program counter, process stack, registers, program code etc. Compared to this, the program code is only the text section. A process passes through different states as it executes. These states may be different in different operating systems. However, the common process states are explained below with the help of a diagram − New This is the state when the process has just been created. It is the initial state in the process life cycle. Ready In the ready state, the process is waiting to be assigned the processor by the short term scheduler, so it can run. This state is immediately after the new state for the process. Ready Suspended The processes in ready suspended state are in secondary memory. They were initially in the ready state in main memory but lack of memory forced them to be suspended and gets placed in the second...
Post a Comment
Read more

Scheduler

  Scheduler   Scheduling Objectives Here, are important objectives of Process scheduling Maximize the number of interactive users within acceptable response times. Achieve a balance between response and utilization. Avoid indefinite postponement and enforce priorities. It also should give reference to the processes holding the key resources  Process Scheduling handles the selection of a process for the processor on the basis of a scheduling algorithm and also the removal of a process from the processor. It is an important part of multiprogramming in operating system. Process scheduling involves short-term scheduling, medium-term scheduling and long-term scheduling. Details about these are given as follows − Long-Term Scheduling Long-term scheduling involves selecting the processes from the storage pool in the secondary memory and loading them into the ready queue in the main memory for execution. This is handled by the long-term scheduler or job scheduler. The long-term s...
Post a Comment
Read more

Exokernel architecture

Exokernel architecture Most of us know what kernels are and how do they work to make programmers’ lives easier. But, how many of us know what exokernels are? I hope you will be able to get a brief introduction on this terminology through this blog. Let’s start with a brief introduction on kernel. What is a kernel? A kernel is the foundational layer of an operating system that functions at a basic level, communicating with hardware and managing resources, such as CPU and the memory. It works as an interface between the user application and the hardware. There   are two main types of kernel 1. Micro kernel 2. Monolithic Kernel 1.  Monolithic architecture 2.      Layerd archtecture . 3.       Virtual machine architecture 4.       Exokernel architecture 5.      Client server architecture   6.       Micro kernel architecture Now let’s head into our main focus. What is an Exokern...
Post a Comment
Read more

Defination of OS(operating system) and its concepts

    What do you mean by operating system?     Definition :  An operating system is a program that act as an interface between the user of a computer and the                                      Computer hardware. Operating system is a first program that gets loaded into the memory through a process called booting. Concepts of operating system : ·                       The purpose of operating system is to provide an environment in which a user can execute program in a convenient and efficient manner. ·                       Operating system is an integrated set of program that ma...
3 comments
Read more