High-Level Architecture

Let s take a high-level look at the GNU/Linux architecture. Figure 2.1 shows the 20,000- foot view of the organization of the GNU/Linux operating system. At the core is the Linux kernel, which mediates access to the underlying hardware resources such as memory, the CPU via the scheduler, and peripherals. The shell (of which there are many different types) provides user access to the kernel. The shell provides command interpretation and the means to load user applications and execute them. Finally, applications are shown that make up the bulk of the GNU/Linux operating system. These applications provide the useful functions for the operating system, such as windowing systems, Web browsers, e-mail programs, language interpreters, and of course, programming and development tools.

Figure 2.1: High-level view of the GNU/Linux operating system.

Within the kernel, we also place the variety of hardware drivers that simplify access to the peripherals (such as the CPU for configuration). Drivers to access the peripherals such as the serial port, display adapter, and network adapter are also found here.

This is a simplistic view, but next we ll dig in a little deeper to understand the makeup of the Linux kernel.