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)

Delving into graphics HAL

After we have an overview of graphics system architecture, we will analyze the Gralloc module, which is the graphics HAL. In the AOSP source code, the skeleton of Gralloc HAL implementation can be found at the following folder:

$AOSP/hardware/libhardware/modules/gralloc

This is a general implementation that provides a reference for developers to create their own Gralloc module. Gralloc will access framebuffer and GPU to provide services to the upper layer. In this section, we will analyze this general implementation first. After the analysis of this general Gralloc HAL module, we will introduce the Gralloc HAL of the Android emulator.

Loading the Gralloc module

When application developers draw images to the screen, there are two ways to...