Understanding the Linux Kernel

The Linux Kernel is a critical part of any Linux distribution. But what is it?

by Pete
Published: Updated: 9 minutes read

Are you prepared to delve into the heart and essence of the Linux operating system? The Kernel holds a prominent place in the Linux community’s discussions, so let’s take a moment to grasp its significance, Alfie.

What is the Linux Kernel exactly?

The Linux kernel stands as the cornerstone of the Linux operating system. It serves as the control center, managing system resources such as memory and processing power. Additionally, it acts as the crucial link connecting software and hardware components. Think of it as the captain of the ship, responsible for supplying fundamental services required by other parts of the operating system, including file system management and network communication, all while maintaining the system’s smooth operation.

What makes the Linux kernel truly exceptional is its open-source nature. This means it’s freely available for use and open to modification by anyone, much like a superhero whose characteristics can be tailored to match the unique needs of various Linux distributions. This is why you encounter a multitude of Linux distributions, each with its own customized version of the kernel, akin to tailor-made suits.

The Linux kernel is also engineered to support an extensive array of hardware, ranging from compact embedded devices to robust servers and supercomputers. It does so by adopting a modular design, allowing developers to add or remove kernel modules as necessary, similar to how you might customize a Mr. Potato Head figure in the world of computers.

Furthermore, the Linux kernel provides support for an extensive range of file systems like ext4, XFS, btrfs, NTFS, and more. This diverse selection empowers users to opt for a file system that best aligns with their requirements, much like having a customized menu.

Where can I find the Kernel on my distro?

The precise location of Linux kernel files on your distribution can be somewhat of a puzzle, and it varies based on the specific distribution you’re using. This resembles a treasure hunt, with different distributions acting like distinct maps.

  • On Debian-based distributions such as Ubuntu, you can typically find kernel files in the /usr/src directory, while the kernel headers reside in /usr/src/linux-headers-version, reminiscent of a clandestine underground hideout.
  • In Red Hat-based distributions like Fedora and CentOS, you’ll come across kernel files within the /usr/src/kernels/ directory, akin to a concealed underground base.
  • Arch Linux conceals kernel files in the /usr/lib/modules/ directory, mirroring a covert underground laboratory.
  • Gentoo Linux opts for the /usr/src/linux/ directory as the location for kernel files, reminiscent of a secretive subterranean vault.

You can also discover your kernel version by executing the command uname -r in the terminal, much like unraveling a secret code. This command unveils the current kernel version operating on your system, similar to disclosing a confidential password.

The Linux Kernel differs from Windows Kernel in several key aspects, setting the stage for an intriguing matchup.

pfarmer@DESKTOP-AP835VM:/usr/src$ uname -r
5.15.0-58-generic

It’s also worth noting that some distributions use a package manager to manage the kernel and its associated files, such as apt, yum, dnf, and pacman, like a personal assistant. So you can also use the package manager of your distribution to search, download and install the kernel, like a personal detective.

What makes up the Kernel?

The Linux kernel is made up of a large number of files and directories.

A list of files and folders on my Ubuntu based 5.15.0-58 Kernel

  • arch: This directory contains architecture-specific code for different CPU architectures, such as x86, ARM, and PowerPC, like a blueprint.
  • block: This directory contains the code that manages block devices, such as hard drives and flash drives, like a traffic controller.
  • Documentation: This directory contains documentation for the kernel, including how to build and configure the kernel, like a manual.
  • drivers: This directory contains device drivers for different hardware devices, such as network cards, storage controllers, and GPUs, like a mechanic.
  • fs: This directory contains the code that manages file systems, such as ext4, NTFS, and XFS, like a librarian.
  • include: This directory contains header files that provide definitions and declarations used by the kernel source code, like a dictionary.
  • init: This directory contains the code that runs during the kernel’s initialization process, such as setting up memory management and process management, like a personal trainer.
  • ipc: This directory contains the code that manages inter-process communication, such as pipes and message queues, like a communicator.
  • kernel: This directory contains the core code of the kernel, such as the scheduler and the system call interface, like a brain.
  • lib: This directory contains library functions used by the kernel, like a helper.
  • mm: This directory contains the code that manages memory management, like a janitor.

and many more, like a big onion with many layers, that make up the Linux kernel, the backbone of the Linux operating system.

Why is there a “Generic” Kernel and what’s it for?

The Generic kernel is a version of the Linux kernel that is built to be stable, compatible with a wide range of hardware and well-tested, it’s a good choice for a wide range of use cases, it’s often used as a base for other kernels, and it’s available as a fallback option for some Linux distributions.

A directory listing of my src folder on my Ubuntu based system

How does the Linux Kernel differ from that of a Windows Kernel?

The Linux Kernel differs from Windows Kernel in several key aspects, setting the stage for an intriguing matchup.

Licensing: The Linux kernel, as open-source software, is freely accessible and customizable by individuals. It’s akin to a superhero with adaptable powers. In contrast, the Windows 11 kernel is proprietary, keeping its source code confidential, akin to a closely guarded secret formula.

Architecture: Linux utilizes a monolithic kernel architecture, where core operating functions reside within the kernel itself. This is comparable to a one-man band, with all functions under one roof. Windows 11 opts for a hybrid kernel architecture, hosting some core functions within the kernel, akin to a soloist, while others exist in separate user space programs, creating a symphony of interactions.

File System: Windows relies primarily on NTFS and exFAT file systems. Linux, however, offers support for a multitude of file systems like ext4, XFS, btrfs, NTFS, providing users with a buffet of choices to suit their needs, similar to a versatile menu.

Security: Linux has a well-earned reputation for robust security, attributed to its open-source nature and the use of permissions and user/group systems to safeguard system resources. It’s akin to having a vigilant security guard. Windows, while equipped with security features such as the Windows Security Center, has occasionally been more susceptible to malware and viruses, akin to an occasional security breach.

Package Management: Linux employs a package management system, simplifying software installation, updates, and removal, much like a trusted personal assistant. In contrast, Windows relies on an executable file-based system, where users manually download and install software, resembling the role of a diligent personal detective.

In Summary

The Linux kernel forms the backbone of the Linux operating system. It efficiently manages system resources, offers fundamental services, embraces open-source flexibility, and adapts to cater to a wide array of operating system needs. Furthermore, it undergoes continuous enhancements by a global community of developers, ensuring an ever-evolving and improved experience, much like an eternal upgrade.