Here you can find the information and source code you need to build an Android-compatible device.
Android is an open-source software stack for mobile devices, and a corresponding open-source project led by Google. We created Android in response to our own experiences launching mobile apps. We wanted to make sure that there was no central point of failure, so that no industry player can restrict or control the innovations of any other. That’s why we created Android, and made its source code open.