Fundamentals of Linux kernel development

Introduction to the 1.Linux kernel

How 1.1.Linux systems Form

Kernel space (Kernel spaces) + user space

User space = User program + C language Library (example: GNC C Libraries)

Kernel space = Kernel + system call Interface (INTERFACE) + architecture-related code

Linux system is divided into the user space kernel space reasons?

The CPU now implements different modes of operation, taking arm as an example

A. User mode (USR)

B. System mode (SYS)

C. External interrupt mode (IRQ)

D. Management Mode (SVC)

E. Fast interrupt mode (FIQ)

F. Data access discontinuation (ABT)

G. Undefined directive exception (und)

The Linux system uses the CPU to run the Linux kernel and application separately, so that the operating system itself is fully protected.

Kernel space and user space are two different states of program execution.

Kernel space, User space

Transfer of user space to kernel space through system calls and hardware interrupts

1.2 Core composition

7 Components

Sci:system call Interface System Invoke interface

Pm:process Management process Management, process creation, process scheduling, process communication,

Mm:memory Management memory management, virtual address and Physical address translation, memory reclamation, (zone address)

Arch: Architecture-related code (ARM system) This place needs to modify its content .

Dd:device Drivers Device Driver

Network stack: Networking protocol stack (Linux supports multiple network protocols)

Vfs:virtual File System virtual filesystem

Fundamentals of Linux kernel development