Linux kernel

• Kernel version consist of Major version.Minor version(even numbers for stable, odd numbers for develpment).Patch version. For example: 2.6.26


• Modules directory: /lib/modules


• Tools to control modules:


• insmod - insmod is a trivial program to insert a module into the kernel. This version of insmod is for kernels 2.5.48 and above. If it detects a kernel with support for old-style modules (for which much of the work was done in userspace), it will attempt to run insmod.old in its place. Most users will want to use modprobe(8) instead, which is cleverer.


• rmmod - simple program to remove a module from the Linux Kernel. Most users will want to use modprobe(8) instead, with the -r option.


• lsmod - is a trivial program which nicely formats the contents of the /proc/modules, showing what kernel modules are currently loaded. The lsmod command displays information only about kernel modules, not about drivers that are compiled directly into the Linux kernel.


• modinfo - program to show information about a Linux Kernel module.


• modprobe - program to add and remove modules from the Linux Kernel


• depmode - program to generate modules.dep and map files. Starts with a system.


• System.map file - is a listing of all symbols along with their address.


• Config file - kernel configuration file generated by make menuconfig/make xconfig/make gconfig


• initrd.img file - contains device drivers which are required to boot and load rest of operating system from disk. Usually SCSI and IDE drivers are stored in this file.


• /etc/modules file contains list of modules, that are loaded during system boot


• /proc/cmdline - options provided to kernel by bootloader