The document discusses the Linux kernel architecture. The kernel manages resources and arbitrates access between users and applications. It includes functions like file systems, process management, device drivers, memory management, and networking. The kernel space runs kernel processes while the user space runs user applications, which interact with the kernel through system calls. The kernel presents a consistent view of data stored on devices using a virtual file system.

1. Linux Kernel Architecture

2. Contents What is Kernel ? Kernel Architecture Overview User Space Kernel Space Kernel Functional Overview File System Process Management Device Driver Memory Management Networking

3. What is Kernel ? The Core of OS a kernel is really nothing more than a resource manager the kernel manages and arbitrates access to the resource between multiple competing users

4. Kernel Architecture Overview User Space Kernel Space User Space System Call Hardware Kernel Space

5. The fundamental architecture of the GNU/Linux

6. The User Space is the space in memory where user applications are executed. The kernel Space is the space in memory where kernel processes run. The user has access to it only through the system call.

7. Linux kernal is a monolithic kernal It includes all the necessary functions

8. Kernel Functional Overview File System Process Management Device Driver Memory Management Networking

9. Kernel Functional Overview

10. Functional Layer & Architectural Layer User Space System Call Hardware MM PM Net DM FS

11. File System It is responsible for storing information on disk and retrieving and updating this information. accessed through system calls eg. FAT16, FAT32, NTFS,ext2, ext3…

12. Type of Files The Unix system has the following types of files: Ordinary Files Directory Files Special Files (devices)‏ FIFO Files for Pipes

13. Virtual File System It manages all the different file system. The virtual file system is designed to present a consistent view of data as stored on hardware devices.

14. Process Management Kernel creates, manages and deletes the processes. Kernal helps to increase the performance of OS, by executing the process in pre emptive manner.

15. Process Management (Cont.)‏ Each process has a unique identifier ( Process ID ). System calls used for process management-”fork”,”exec”,”kill”,”exit”,”signal”

16. States Running Waiting Stopped Zombie

17. Device Driver Linux kernel contains the code to manage the HW controller . Character devices, Block devices,Network devices are different types of devices

18. Memory Management Physical memory is limited. Virtual memory is developed to overcome this limitation.

19. Linux network layers The network subsystem allows Linux systems to connect to other systems over a network. The network subsystem abstracts implementation details of network devices and protocols