AOSP

What and why

Android Open Source Project is an open source operating system development project maintained by Google where anyone is free to contribute code and fixes to the project repository. Main intention behind its usage is to tweak existing Android default behavior for their personalize experience.

Inside Android Open Source Project

AOSP covers a range of software layers within the operating system, providing access points and tools for hardware and app developers alike. It can be separated into two parts:

1. Lower level comprises of Linux kernel and HAL(Hardware Abstraction Layer)
2. Higher level comprises of Application layer, Framework layer and Native layer.

Its a complete solution for Android hardware and software developers.

Different layers of AOSP from Hardware to Software(Bottom to Top)

Setup and how to use AOSP

https://source.android.com/setup/build/downloading

Once the code is downloaded and synced in Git repository, we build the codebase for particular hardware through “make” command, successful build results into Image for that hardware.

For eg : if code change is required for default Bluetooth application, then we need to navigate to this location and make changes accordingly:

platform/packages/apps/Bluetooth - Git at Google