Summary:

This post describes the tutorial on Linux kernel character device drivers. The tutorial introduces the main concepts behind character devices, including major and minor numbers, file operations such as open, read, write, and release, and the role of struct cdev in connecting device identifiers with file operation handlers. It then presents a simple example driver that allocates a character device number, registers a cdev, and implements basic read and write behavior through a kernel buffer.

The tutorial also shows how to test the driver from user space by checking registered devices, creating a device node with mknod, and interacting with the driver through standard file operations. In this way, it provides an end-to-end introduction that goes from the conceptual foundations of character devices to writing, loading, and testing a minimal character driver in practice.

My experience:

Everything worked smoothly. I did not run into any real technical issues while following the tutorial, and the driver behaved as expected during testing.

The only problems I had were caused by reading mistakes on my side rather than by the tutorial itself. After correcting those mistakes, I was able to complete the steps successfully.