从 AOSP 源代码树构建 Android 系统应用

Question

Is there a way to build an Android system app from AOSP without having to clone the entire code tree and having to build the entire OS?

Just being able to build the unmodified app from a Linux shell is sufficient, with any toolchain that will do the job. Being able to make modifications in an IDE (Eclipse or Android Studio) is not a requirement (a text editor will do for making changes).

The app in question is CarrierConfig . Most of the app is just assets, the code consists of just one single Java class (~400 lines of code), but with four internal dependencies not exposed through the SDK API:

android.annotation.Nullable
android.os.PersistableBundle.restoreFromXml(XmlPullParser)
android.telephony.TelephonyManager.from(Context)
android.telephony.TelephonyManager#getCarrierIdFromMccMnc(String)

These are what prevents me from simple adding a generic build.gradle and running it through the gradle toolchain. The build artifact is a simple APK file, with which I would then patch the system image.

So how would I build this app without needing the entire AOSP source code (just the actual dependencies, and dependencies of dependencies etc.)?

Answer 1

Not a complete answer (yet), but some snippets I was able to find out so far:

Downloading just individual projects from the source tree

This is what I have been able to piece together from various instructions—untested so far:

mkdir <dir>
cd <dir>
repo init -u <url> -b <branch>
repo sync <project-list>

Where

• <dir> is a dir on your system where you are going to keep the source
• <url> is the URL for your build, eg:
  • AOSP: https://android.googlesource.com/platform/manifest
  • LineageOS: https://github.com/LineageOS/android.git
• <branch> is the branch to check out (omit -b to check out the master branch)
  • AOSP branches are found at https://source.android.com/setup/start/build-numbers#source-code-tags-and-builds
  • LineageOS branches are found at https://github.com/LineageOS/android/branches
• <project-list> is a list of projects to fetch (if omitted, repo sync will fetch the entire source tree). Projects can be indicated either by their name or by their path within the source tree, separated with spaces.

( source 1 , source 2 , source 3 , source 4 )

Figuring out which repos you need can get tricky, and if your dependencies have further dependencies, this can become a time-comsuming process.

Also I haven't figured out if the next step actually works with a source tree stripped down in this manner.

Building individual projects

If you just need to build a single project, you can use mmm for that:

. build/envsetup.sh
lunch
mmm path/to/the/project/

( source )