Contents

  1. Communication Channels
  2. Package naming scheme
  3. Source package structure
  4. Updating the source packages
  5. Upstream repository of tools in Android SDK
  6. Android's upstream version names
  7. Android SDK version declarations
  8. Original android-tools package
  9. Why is this so complicated?
  10. Needs doing
  11. See Also

This page is a gathering place for information about the android-tools packaging team, which is focused on packaging the Android development tools for Debian. There are also some packages which help run Debian in a chroot on Android. The goal of this team is to get as much of the Android SDK and development tools into Debian as possible. There are many advantages to having the SDK and tools in Debian, rather than relying only on the Google distributions:

To read more about the rationale behind this work, see this blog post: https://guardianproject.info/2015/04/30/getting-android-tools-into-debian/

To communicate with this team, join our low traffic mailing list, android-tools-devel@lists.alioth.debian.org and on the IRC channel #debian-mobile (webchat).

The binaries for the Android SDK downloadable from Google are not completely free software but the source code is free software so Debian is packaging it. The full SDK cannot be completely installed from Debian packages yet. Until it is fully available, you can install either Sylvain Beucler's libre Android rebuilds or Google's non-free i386-only builds.

Communication Channels

There are a number of ways that people working on packaging Android Tools communicate. Here is a list:

Package naming scheme

The naming scheme for android-tools packages is as follows:

Source package structure

The structure of each source package is documented in the README.source of each source package for this team:

Updating the source packages

The packages in this team are structured somewhat unusually because we are trying to keep the source packages as close as possible to the upstream source organization while still working in a Debian way. Google builds the Android OS and SDK as one giant thing, something like 10 gigs of source code. But the code is broken up into many different git repos that are coordinated using the Android team's tool called repo. Also, there are lots of shared libraries used between the various Android SDK tools, but since everything is always built together, those shared libraries are unversioned.

All this means that it is essential that any Android SDK package is only built against the exact same version of all its Build-Depends and only uses the exact same version of an Android SDK package as a Depends. To achieve that, we use the substvars variable in dependency declarations: (>= ${source:Version}).

Additionally, because of this and the circular dependencies, it is important to upload updates in the correct order. Some packages also have to be uploaded using a multi-stage method. Here is the estimated upload order:

Each packages belonging to the same stage are unrelated to each other and can be uploaded in any order.

This order only represents one possible way of updating all of them to a new major version. In practice, you can delay or advance any packages as long as the build-dependencies satisfy.

Upstream repository of tools in Android SDK

Tools in Android SDK come from various repositories. Here is a list of tools consisting the entire Android SDK, with each tool followed with the corresponding upstream repository name.

SDK Tools

SDK Platform-tools

SDK Build-tools

Reverse engineering tools

dexdump apktool gplaycli androguard enjarify dmtracedump

Other Tools

Android's upstream version names

There are many naming schemes for versions in Android, and none are used everywhere. For the Android OS itself, there are three schemes: version names, like Gingerbread or Kitkat; version numbers, like 2.3.7 or 4.4.2; and, "API level" numbers, like android-10 or android-19. None of these line up with each other. For example, the Jelly Bean name spans 4.1 through 4.3.1 and android-16 through android-18. The version numbers and API level also do not line up, with android-14 covering 4.0.1 - 4.0.2, android-15 covering 4.0.3 - 4.0.4, but android-16 covers all of 4.1.x.

The madness doesn't end there. Next up we have SDK version numbers, which are like 20, or 23.0.2. Part of the SDK includes the build-tools package, which has its own version numbers, which are like 18.1.1 and 20.0.0, but these do not line up with the SDK version numbers. The platform-tools seems to have its own versioning scheme also, but it is not really exposed. Then there are the NDK release numbers, which are like r8b or r10, and they also do not line up with anything else.

In the git repo, there are a mishmash of tags and branches that do not represent all of these various versions. There does seem to be consistent tagging of the OS releases, you can see those listed under Source Code Tags and Builds. There are a few branches that seem to line up to the SDK version numbers, like tools_r21 and tools_r22.2, but there is not a complete set of those branches.

example versions

Android SDK Tools seems to have it's own versioning scheme, since the major version is ahead of the SDK major version:

Android SDK Build-tools seems to follow the SDK major version, but have its own minor and micro versions:

Android SDK Platform-tools seems to follow the SDK major version only.

You can find the official Google package names and versions in the index XML files that the android tool downloads when doing updates:

Android SDK version declarations

However, the exact version number of Android SDK toolsets can be found in a source.properties under each directories. Here are the source locations of each version declaration:

Which matches the official release notes.

Note that according to the source code the major version number of Platform-tools and Build-tools is simply the API Level, which is defined here. But for SDK Tools it follows its own version pattern and does not relate to the API Level.

Some tools tracks their own version and do not follow the SDK version:

Original android-tools package

This team started with the android-tools package, which is a manually assembled collection of source code needed to build adb, fastboot, etc. This approach is not maintainable in the long run, especially as we work to add the whole Android SDK. So the android-tools package is deprecated, and will be replaced by the collection of packages described above.

Why is this so complicated?

Packaging all of these Android SDK Tools is so complicated because the source code is organized into semi-arbitrary "projects" that are split up between many different git repos. Those git repos are then all checked out at the same time using Google's crazy repo tool. Then the entire Android OS and SDK are built using a single, unified build system that requires something like 8 gigs of source code be downloaded. On top of that, one of the more confusing aspects of this whole project is that the same source code base is used to build the OS and the SDK. Those two can start with the same source code files, and end up with very different resulting binaries.

shared libraries within the Android SDK packages

The Android SDK has a number of private libraries that are shared between many different utilities that are part of the Android SDK. Upstream statically links them into each executable. That didn't seem very Debian-ish, so instead they are structured as private shared libraries. Nothing should link to these android-lib* shared libraries that is not part of the Android source. This private shared library arrangement allows for security patches in the android shared code to be applied without having to rebuild everything.

All of the android-* packages must be updated to the latest version at the same time. It is more unpredictable to have android-* packages at different upstream versions since no one is running that configuration, and upstream does not do anything to support that (e.g. no versioned ABI, etc). Therefore, the ABI is guaranteed to be compatible since they'll all be built together. In practice, this means that the process of updating to the latest upstream version has to start from the most core packages, then progress to the ones that depend on it.

A single source package might make some things easier, but it would be about 8-12 gigs in size. That would make it very difficult for many people to work with that source package.

Needs doing

There is lots left to do before someone can do Android development using only official Debian packages. The best way to get started is to join the email list and ask there. We're also in IRC at #debian-mobile. Here are some general topics that need work:

fdroidserver

fdroidserver is the tool suite for managing FDroid app repos and making release builds. It uses the Android SDK and NDK to make the builds and work with APKs. There are three notable milestones for fdroidserver packaging needs:

  1. everything to create and manage app repos
  2. everything to make pure Java builds
  3. everything to make native builds

The first milestone will be done once the aapt package is accepted into Debian. It is part of the android-platform-frameworks-base package that is waiting in the NEW queue.

low-hanging fruit

Here are a couple of easy tasks to do that will further this effort along:

See Also