insmod command in Linux with examples

insmod command in Linux systems is used to insert modules into the kernel. Linux is an Operating System that allows the user to load kernel modules on run time to extend the kernel functionalities. LKMs(Loadable Kernel Modules) are usually used to add support for new hardware (as device drivers) and/or filesystems, or for adding system calls. This command here inserts the kernel object file (.ko) into the kernel with/without arguments, along with a few additional options.

Syntax

insmod [file name] [module-options...]

where,

• filename: The path or name of the kernel object file (.ko) that you want to insert.
• module-options: These are optional arguments that can be passed to the module if it supports parameters. The specific arguments depend on how the module is written.

Key Options for the insmod Command

1. insmod command with help option

The insmod command throws an error if no options, filename or arguments are passed. So, when we use the -h option, it gives the general syntax along with the various options that can be used with the insmod command.

insmod -h

2. insmod command with version option

This is used to view the version of the insmod command.

insmod -V

Examples of Using the insmod Command

1. insmod + file name

This command is used to insert the LKM file (.ko) into the Linux Kernel. The working directory is changed to the one with the LKM file, and then the command is executed. Root privilege is needed to run this instruction.

Note: The LKM file used here is present in the desktop(which is the working directory), and doesn't take any arguments, and prints a message to the system log. This message can be viewed by using the dmesg command.

sudo insmod geeksforgeeks.ko

Example:

2. insmod + file directory + file name

Like the previous command, insmod works when you specify the file directory along with the LKM file's name. This is illustrated below.

Example:

sudo insmod /home/mukkesh/Desktop/geeksforgeeks.ko

3. Passing parameters to the module using insmod

LKM files can have parameters/arguments passed to them through the insmod command. These arguments essentially act as inputs for the LKMs. Depending on how the LKM is written, the arguments are used.

Note:The LKM used here takes the string parameter "user" and prints a message which includes the passed parameter.

Example:

sudo insmod geeks4geeks.ko user="Mukkesh"

Conclusion

The insmod command is a powerful tool for managing Loadable Kernel Modules (LKMs) in Linux. It provides direct control over which modules are inserted into the kernel, making it ideal for developers and advanced users who need to test or customize kernel functionality. While insmod gives fine-grained control, it requires manual handling of module dependencies. For most users, modprobe is a more convenient alternative as it automates the management of module dependencies.