Linux Kernel system introduction (1)

1. Linux kernel Introduction

Now let's take a high-level look at the GNU/Linux operating system architecture. You can consider the operating system at two levels, as shown in figure 1.

Figure 1. Basic architecture of the GNU/Linux operating system

The top is the user or application) space. This is where your application runs. The user space is the kernel space, and the Linux kernel is located here.

Gnu c Library glibc. It provides a system call interface to connect to the kernel, and a conversion mechanism between the user space application and the kernel. This is very important because the kernel and user space applications use different protective address spaces. Each user space process uses its own virtual address space, while the kernel occupies a separate address space.

The Linux kernel can be further divided into three layers. At the top is the system call interface, which implements some basic functions, such as read and write. The kernel code under the System Call interface can be more accurately defined as the kernel code independent of the architecture. These codes are common to all the processor architectures supported by Linux. Under these codes, it is the code that relies on the architecture and forms part of the BSPBoard Support Package. These codes are used as processors and platform-specific code for a given architecture.

In the Linux kernel