Hello, if you want to understand the Linux Kernel Modules and Drivers, you've come to the right place! I always had this itch in the back of my head to understand the Linux Kernel from it's depth and Kernel Modules and Drivers are a great starting point (personally). And we'll start with Kernel Modules as they are dynamic in the sense of that they are modular which means that they can be loaded and unloaded at runtime as we wish. Hence reducing the efforts of compiling the kernel with menuconfig or another way (that's another rabbit hole we'll be going down with later).

NOTE Not All Device Drivers are to be necessarily to be compiled with The Linux Kernel but only few are to be such as CPU driver, Memory Controller and a few others which are atomically necessary for successful completion of bootprocess

IMPORTANT For the purpose of it, we'll need some tools on our system, I hope you're using Fedora Linux too, so run the following command on your terminal :

sudo dnf install kernel-devel gcc make

The computers we use have many components and these device drivers enable us to use these devices, like the CPU, Memory Controller, Disk Controllers, System timers and few other components are probed on boot which makes our system usable. These components (device drivers) are to be compiled within the kernel to make the boot process a success, otherwise the device just simply won't boot even if there is necessary harware, because if the system can't detect them, then the boot sequence will just dump the process with Kernel Panics. Hence not all but these necessary hardware drivers must be compiled within the kernel to successfully boot our device up and get going on with the kernel modules and device drivers (this article or guide, whatever you may think of this doc as).

There are other kinds of device drivers which can be loaded ondemand such as Drivers for displays, USBs, network hardwares and other stuff. These loadable kernel modules can also be used to print Hello World in the Kernel Logs 😉 which will serve us right for the learning purpose for going further with linux kernel modules and device drivers. The filesystem drivers such as EXT4, BTRFS, ZFS, XFS, NFS, FAT, and other filesystems are LKMs (Loadable Kernel Modules) as they are loaded after the kernel loads these filesystems and mounts them after which the PID 1 starts.

NOTE Each Directory have a README file which will explain the respective
concept and procedure to follow and build Linux Kernel Drivers and Modules.
See You There! 🎉