Introduction to Linux Kernel

Introduction to Linux Kernel
www.tutorialsdaddy.com

This is the first chapter of Linux device driver Tutorials. In this
chapter we will discuss below topics
1) basic introduction to Linux
2) Architecture of Linux
3) Main Features of linux
4) introduction to linux kernel
5) Different subsystems of linux kernel
Agenda

1) Portable
2) Open source
3) Multi-user
4) Hierarchal file system
5) Security
6) Memory Protection
7) Shared libraries
Linux Main features

Linux kernel version scheme
Linux version is released as x.y.z.
1) Development version
x:- release number
y:- Odd number
z:- identifies the exact release version number
Example:- 2.5.54,2.7.56
2) Stable version
y:- even number
Example:- 2.2.50,2.4.60

Linux architecture
To protect data and functionality from fault or some unwanted access in
linux, virtual memory is divided into user space and kernel space.

•User space:- All the user application runs on User space.
•Kernel Space:- Kernel space is the privilege space where mainly
operating system kernel and device driver execute.
•Gnu C-library:- This library expose APIs to user application which
helps user application to interacts with kernel by using System calls.
•for example in our user space application we generally use printf()
which is defined in C-lib and internally calls write() system call.
•System Call Interface:- System call interface provides the
implementation of various System calls.
•Kernel:- Below system call interface we have kernel code which
is architecture independent code which is same for all the processor.
•Device driver:- Device driver is the program which actually interacts
and controls the hardware’s.

Kernel Subsystems

Linux subsystems
1. Process management :- This system has the responsibility of
maintaining the execution of each process. Main part of process
management subsystem is Schedule which control the scheduling or
exiting of every process.
2. Memory Management:- This system maintain the system memory
and control the memory request from each process. Its manage virtual
to physical translation of process. It lies in /linux/mm.
3. Virtual File system :- This subsystem provides the abstraction APIs
like open() , Read() and write() etc irrespective of type of file system.
User doesn’t need to worry about the file system types. VFS has the
responsibility of passing the request of user to respective file system
for which the request is raised by user application.

4. Network Stack:- It manage linux IP network or we can say
everything related to network is managed by N/W subsystem.
5. System Call interface:- It provides an interface to the applications
running in user space for getting the controlled access to
hardware. This interface provides a mechanism by which
applications can request operating system resources.

Q/A
Post your question @
http://www.tutorialsdaddy.com/forums/foru
m/linux-device-driver/

Thank You

Introduction to Linux Kernel

In this document