AOSP Learning Path

The Android Open Source Project (AOSP) is the core of the Android operating system, providing developers with the source code and tools needed to create custom Android experiences. This article introduces AOSP, explaining its role and importance in the Android ecosystem. It also offers guidance on setting up the development environment and understanding the AOSP directory structure, which is essential for effective navigation and development.

Android System Architecture

• Android OS Layers: Learn about the different layers of the Android operating system, including the Linux kernel, wakelocks, low-memory killer, binder, anonymous shared memory (ashmem), alarm, logger, and other key Android features.

AOSP Build System

• Build Process: Understand the AOSP build process, including the lunch command, building AOSP from source, and customizing the build.

• Configuration and Tools: Cover configuration, envsetup.sh, function definitions, main make recipes, cleaning, module build templates, output, build recipes, and the default droid build.

• SDK and NDK: Instructions for building the SDK for Linux, Mac OS, and Windows, as well as building the CTS, NDK, and updating the API.

• Advanced Building: Techniques for building a single module, building out of tree, building recursively in-tree, and basic AOSP modifications like adding a device, app, app overlay, or native tool/daemon.

Hardware Abstraction Layer (HAL)

• Introduction and Integration: Introduction to HAL, writing a custom HAL, and integrating HAL with the Android framework.

Android Framework

• Framework Components: Cover Android framework components, modifying them, adding new features, and starting the framework.

• Core Building Blocks and Services: Core building blocks, system services, boot animation, dex optimization, apps startup, utilities, and commands.

• Managers and Utilities: Audio manager, location manager, power manager, resource manager, activity manager, content provider, package manager, window manager, USB manager, notification manager, and useful ADB commands.

• Advanced Topics: Topics include Android booting sequence, process lifecycle, control flow from framework to kernel layer, and more.

System Services

• Overview and Interaction: Overview of Android system services, creating custom system services, and interacting with existing system services.

JNI and AOSP

• JNI Lab: JNI in AOSP, including ashmem with the binder.

Custom ROM Development

• Introduction and Customization: Introduction to custom ROMs, building and flashing a custom ROM, and customizing the user interface and features.

Kernel and Toolchain

• Kernel and Tools: Information on kernel, busybox, external toolchain, and interrupts.

Security in AOSP

• Security Model: Android’s security model, permissions, SELinux policies, and NFC security and implementation.

Testing and Debugging

• Debugging Tools: ADB for debugging, logcat, debugging tools, writing and running unit tests, and logger.

Simple Applications and Components

• Applications and Components: Creating simple applications, components, and system applications.

Contributing to AOSP

• Contribution Process: Understanding the contribution process, submitting patches and code reviews, and engaging with the AOSP community.