Book Image

Android System Programming

By : Roger Ye, Shen Liu
Book Image

Android System Programming

By: Roger Ye, Shen Liu

Overview of this book

Android system programming involves both hardware and software knowledge to work on system level programming. The developers need to use various techniques to debug the different components in the target devices. With all the challenges, you usually have a deep learning curve to master relevant knowledge in this area. This book will not only give you the key knowledge you need to understand Android system programming, but will also prepare you as you get hands-on with projects and gain debugging skills that you can use in your future projects. You will start by exploring the basic setup of AOSP, and building and testing an emulator image. In the first project, you will learn how to customize and extend the Android emulator. Then you’ll move on to the real challenge—building your own Android system on VirtualBox. You’ll see how to debug the init process, resolve the bootloader issue, and enable various hardware interfaces. When you have a complete system, you will learn how to patch and upgrade it through recovery. Throughout the book, you will get to know useful tips on how to integrate and reuse existing open source projects such as LineageOS (CyanogenMod), Android-x86, Xposed, and GApps in your own system.
Table of Contents (15 chapters)

Analyzing the Android start up process

The Android system boot up sequence is similar to other embedded Linux systems that start from the Boot ROM inside the processor. The Boot ROM will find the bootloader. The bootloader will load the kernel and ramdisk image. The kernel uses the ramdisk as the root filesystem. In a desktop Linux environment, once the kernel initializes the essential devices, it will remount the root filesystem on physical storage such as a hard disk. In Android, the various partitions (system, data, cache, and so on) will be mounted to the root filesystem in memory instead of a storage device. The kernel will invoke the init process in the ramdisk to start the rest of the system, as shown in the following figure:

Bootloader and the kernel

As...