About book The Linux Kernel

This book requires that you first read

Linux Basics
C Programming

This book is intended for advanced readers.

The book's title page and structure were originally influenced by the article "Splitting the Kernel" in the Linux Device Drivers book, which included a diagram. The diagram's colorful matrix design was borrowed from the Interactive map of the Linux kernel. Additionally, the layered presentation of information in the book was inspired by the OSI model's layers. The number of layers and functionalities is intentionally close to the magical number seven.

Layers

Applications and libraries in user mode above the kernel can be associated with the Application layer of the OSI model.

Upper layers:

User space interfaces - Facade of the kernel, mostly represented by system calls. It can be associated with the Presentation layer of the OSI model.

Virtual - Provides aggregated services to the upper layer, named after virtual memory and the Virtual File System. Similar to the Session layer.

Middle layers:

Bridges - Manages interoperability, named after the Bridge pattern. Similar to the Transport layer.

Logical - Provides logical implementations, named after logical memory, addresses, and logical file systems. Similar to the Network layer.

Lower layers, similar to the Data link layer:

Devices control - Abstractions and control of hardware interfaces, including classes of devices and hardware-independent generic devices.

Hardware interfaces - Direct hardware interfaces and hardware-dependent drivers.

Functionalities

The functionalities Multitasking, Memory, Storage, and Networking are familiar and obvious, while Human Interface and System need some explanation. The Human Interface functionality covers topics more associated with human users than fundamental computing. Naturally, HID (Human Interface Devices) belongs here, hence the name, along with Multimedia. Character devices, though used as byte streams in System and Storage, are also assigned to this functionality. The System functionality covers fundamental and common functions. The common system calls infrastructure of the kernel is described under this functionality, while specific system calls and interfaces are detailed under their corresponding functionalities.

The two-dimensional layout, instead of a linear TOC layout, allows effective organization of the book content and indexing of existing documentation and man pages.

Contribution

The book needs contributors. Here are the guidelines:

Make articles complete, continuous, and appealing.
- Fix typos and rephrase for clarity.
- Maintain consistent formatting.
Keep information updated by replacing obsolete content with modern equivalents.
Share your knowledge and experience about the kernel.
Explore the source code and describe it.
Add explanations to incomplete sections.
Copy-paste text from Wikipedia where appropriate.
Add links to external resources using templates: