XDA Developers' Android Hacker's Toolkit

Chapter 1: Android OS Internals: Understanding How Your Device Starts

In this chapter:

• The penguin down below: the Linux kernel

• Bootstrapping: How your device starts

• An introduction to custom bootloader and custom recovery processes

To fully understand the process of rooting your device, gaining the control and power you need to truly customize it, you need to understand a little about how the Android operating system works—how the device goes from being powered off to a fully functioning state. It is in this process that developers usually exploit weaknesses to gain full access to the device. Usually some step in the boot process allows a developer to insert a bit of code or a script, and thus access functionality not intended by the Original Equipment Manufacturer (OEM).

Linux Development and Open Source

Linux began in 1991 with Linus Torvalds working to make a completely free and open source operating system that could be used by hobbyists, academia and hackers. His operating system has grown to be one of the most powerful and flexible in the world today. From a handful of unknown geeks, the developer base has matured to include thousands of contributors every year. Some of the finest names in computer science and programming work on the development not only of Linux but also of Android.

Linux remains completely free and completely open source. This allows companies and individuals to have access to the power of computing devices without the complex legal and copyright ...