Android Tutorial Lesson 6 - Arena

What is involved in releasing the source code for a new
Android version?
Releasing the source code for a new version of the Android
platform is a significant process. First, the software gets
built into a system image for a device, and put through
various forms of certification, including government
regulatory certification for the regions the phones will be
deployed. It also goes through operator testing. This is an
important phase of the process, since it helps shake out a
lot of software bugs.
Once the release is approved by the regulators and
operators, the manufacturer begins mass producing
devices, and we turn to releasing the source code.
Simultaneous to mass production the Google team kicks
off several efforts to prepare the open source release.
These efforts include final API changes and documentation
(to reflect any changes that were made during qualification
testing, for example), preparing an SDK for the new version,
and launching the platform compatibility information.
Also included is a final legal sign-off to release the code
into open source.
Just as open source contributors are
required to sign a Contributors License Agreement attesting
to their IP ownership of their contribution, Google too must
verify that it is clear to make contributions.
Starting at the time mass production begins, the software
release process usually takes around a month, which often
roughly places source code releases around the same time
that the devices reach users.
How does the AOSP relate to the Android Compatibility
Program?
The Android Open-Source Project maintains the Android
software, and develops new versions. Since it's open-
source, this software can be used for any purpose,
including to ship devices that are not compatible with other
devices based on the same source.
The function of the Android Compatibility Program is to
define a baseline implementation of Android that is
compatible with third-party apps written by developers.
Devices that are "Android compatible" may participate in
the Android ecosystem, including Android Market; devices
that don't meet the compatibility requirements exist outside
that ecosystem.
In other words, the Android Compatibility Program is how
we separate "Android compatible devices" from devices
that merely run derivatives of the source code. We
welcome all uses of the Android source code, but only
Android compatible devices — as defined and tested by the
Android Compatibility Program — may participate in the
Android ecosystem.
How can I contribute to Android?
There are a number of ways you can contribute to Android.
You can report bugs, write apps for Android, or contribute
source code to the Android Open-Source Project.
There are some limits on the kinds of code contributions
we are willing or able to accept. For instance, someone
might want to contribute an alternative application API,
such as a full C++-based environment. We would decline
that contribution, since Android is focused on applications
that run in the Dalvik VM. Alternatively, we won't accept
contributions such as GPL or LGPL libraries that are
incompatible with our licensing goals.
We encourage those interested in contributing source code
to contact us via the AOSP Community page prior to
beginning any work. You can find more information on this
topic at the Getting Involved page.
How do I become an Android committer?
The Android Open Source Project doesn't really have a
notion of a "committer". All contributions — including those
authored by Google employees — go through a web-based
system known as "gerrit" that's part of the Android
engineering process. This system works in tandem with the
git source code management system to cleanly manage
source code contributions.
Once submitted, changes need to be accepted by a
designated Approver. Approvers are typically Google
employees, but the same approvers are responsible for all
submissions, regardless of origin.
You can find more information on this topic at the
Submitting Patches page.
Compatibility
What does "compatibility"mean?
We define an "Android compatible" device as one that can
run any application written by third-party developers using
the Android SDK and NDK. We use this as a filter to
separate devices that can participate in the Android app
ecosystem, and those that cannot. Devices that are
properly compatible can seek approval to use the Android
trademark.
Devices that are not compatible are merely
derived from the Android source code and may not use the
Android trademark.
In other words, compatibility is a prerequisite to participate
in the Android apps ecosystem. Anyone is welcome to use
the Android source code, but if the device isn't compatible,
it's not considered part of the Android ecosystem.