Book excerpt: The Complete Guide to Customizing Android for New IoT and Embedded Devices Inside the Android OS is a comprehensive guide and reference for technical professionals who want to customize and integrate Android into embedded devices, and construct or maintain successful Android-based products. Replete with code examples, it encourages you to create your own working code as you read--whether for personal insight or a professional project in the fast-growing marketplace for smart IoT devices. Expert Android developers G. Blake Meike and Larry Schiefer respond to the real-world needs of embedded and IoT developers moving to Android. After presenting an accessible introduction to the Android environment, they guide you through boot, subsystem startup, hardware interfaces, and application support--offering essential knowledge without ever becoming obscure or overly specialized. Reflecting Android's continuing evolution, Meike and Schiefer help you take advantage of relevant innovations, from the ART application runtime environment to Project Treble. Throughout, a book-length project covers all you need to start implementing your own custom Android devices, one step at a time. You will: Assess advantages and tradeoffs using Android in smart IoT devices Master practical processes for customizing Android Set up a build platform, download the AOSP source, and build an Android image Explore Android's components, architecture, source code, and development tools Understand essential kernel modules that are unique to Android Use Android's extensive security infrastructure to protect devices and users Walk through Android boot, from power-on through system initialization Explore subsystem startup, and use Zygote containers to control application processes Interface with hardware through Android's Hardware Abstraction Layer (HAL) Provide access to Java programs via Java Native Interface (JNI) Gain new flexibility by using binderized HAL (Project Treble) Implement native C/C++ or Java client apps without bundling vendor libraries