Why Linux Uses Its Bus, Device, and Driver Model – A Deep Dive

This article shares a slide deck created several years ago that explains the design of Linux’s bus, device, and driver model. It aims to clarify why Linux adopts this architecture and what the main design principles are.

The slides cover the following topics:

Imagining an Ethernet controller on a board

Decoupling components

Providing a unified interface

Understanding the bus, device, and driver relationship

Matching devices to drivers

Distinguishing devices from drivers

Using the /sys filesystem

Viewing devices through /class Bus chaining and power management

Describing devices in DTS and drivers in C code

Matching ACPI entries to drivers

Automatic loading of driver modules

Sysfs modalias mechanism

Driver override capabilities

Kernel object ( kobject) fundamentals

Reference counting with kref Kernel sets via kset Subsystem handling with subsys Each slide (illustrated by the accompanying images) demonstrates the concept, often with diagrams of the kernel’s internal structures, showing how these mechanisms work together to achieve modularity, extensibility, and reliable power management in the Linux kernel.