Linux Kernel Management

Module 9 – Kernel Administration ♦ Overview The innermost layer of Linux operating system is the kernel, which is a thin layer of software between hardware and software applications. This module deals with the kernel source structure, loading and unloading of kernel modules. ♦ Lessons covered in this module ► The Linux Kernel Source Structure ► Loading and Unloading Kernel Modules ► Compiling and Building Custom Kernels

Linux Kernel Management ♦ Introduction The innermost layer of Linux operating system is the kernel, which is a thin layer of software between hardware and software applications. Kernel has many directories and the structure of the Linux kernel source has to be understood as it helps in knowing various processes performed by the system. ♦ Topics covered in this lesson ► Linux Kernel Source Structure ► Referring a Kernel Source Structure Lesson 1 – The Linux Kernel Source Structure

Linux Kernel Management Topic 1 - Linux Kernel Source Structure ♦ Linux distributions such as Red Hat and Debian include the Kernel sources in them. ♦ The Linux kernel that gets installed on a Linux system is made from the Kernel sources included in the Linux distributions. Linux Kernel Source

Linux Kernel Management ♦ To refer a Linux kernel the following subtopics will be a guide: ► System Startup and Initialization ► Memory Management ► Kernel ► PCI ► Interprocess Communication ► Interrupt Handling ► Device Drivers ► File Systems ► Network ► Modules Topic 2 - Referring a Kernel Source Structure

Linux Kernel Management Lesson 2 – Loading and Unloading Kernel Modules ♦ Introduction Linux is a monolithic kernel or in other words it is a large program in which all the functional components of the kernel have access to all of its internal data structures and routines. Linux kernel modules can be loaded or unloaded into the kernel as per the requirement. ♦ Topics Covered in this module ► Kernel Version ► Loading and Unloading Kernel Modules

Linux Kernel Management ♦ Fresh versions of the kernel are constantly made available, which will offer better support for devices and for an efficiently running system. ♦ Linux kernel will have a version number that has three parts as given below ► major number- The major number will increase when the kernel has major changes. ► minor number- The minor number defines stability. ► revision number- The revision number will refer to the corrected versions. Topic 1 – Kernel Version

Linux Kernel Management Topic 2 - Loading and Unloading Kernel Modules ♦ A Linux kernel has components known as Modules that can be loaded and added to it as required. ♦ The modprobe command is a common command, which calls insmod command for loading modules and rmmod for unloading modules ♦ modprobe command- Manual installing a module can be done using the modprobe command and the module name

Linux Kernel Management ♦ Introduction A custom kernel is a kernel that is built with a configuration file other than the given generic configuration file. ♦ Topics covered in this lesson ► Building Custom Kernels ► Compiling Custom Kernels Lesson 3 - Compiling and Building Custom Kernels

Linux Kernel Management ♦ Building custom kernels involves building the kernel file and kernel modules. ♦ Configuring the Custom or New Kernel ► Configuration is the most tedious and essential part of building a custom kernel. ► During configuration, the hardware, file systems and other features that will be supported by the kernel, are decided ♦ Building a Custom Kernel Building a custom kernel is done by carrying out the tasks as root Topic 1 – Building Custom Kernels

Linux Kernel Management Topic 2 – Compiling the Custom Kernels ♦ After building a custom kernel, it has to be installed and compiled on the system. ♦ The steps involved in compiling a custom kernel are: ► make modules _install has to be used for installing the kernel modules ♦ Verification has to be made on the custom kernel

Linux Kernel Management Conclusion ♦ Summary ► Kernel is the innermost core of the operating system that is a thin layer between hardware and software applications. ► The Linux kernel source structure can be referred to know about the system functions. ► A kernel module is loaded whenever a kernel requires it. ► A custom kernel is built by creating a new configuration file. ♦ Question and Answer Session