Summary

The GPIO lines are really important and versatile computer peripherals, and their usage is quite essential for every embedded computer. In this chapter, we discovered several ways to manage these devices in both user and kernel-space, presenting different techniques to use them.

In the next chapter, we're going to discover another most important embedded computer peripheral, that is, the serial line! Until now, we simply used it to support the kernel (and bootloaders) serial console only, but it can be used in tons of different way; in fact, even in its age (these kinds of devices are practically the only ones still surviving until the beginning of the computer era), the serial lines (or serial ports) are still present, especially in devices for industrial applications.