Build An Android Virtual Device On The Cloud

In this code lab, you will learn how to build an Android Virtual Device(AVD), sdk_phone_x86_64 on the cloud.

Android build process in a nutshell

Android Build Process

Android source code

Glancing through following pointers will give you a sense of Android codebase & development universe.

To navigate the codebase: Android Code Search
- Search: sdk_phone_x86_64.mk
The code & revision management: Android Software Management
Check Android & Pixel SW releases: Codenames, Tags, and Build Numbers
Understand Source Control Workflow

Download Android source code

Pick a branch from AOSP branch list.
Read Downloading the Source to learn more.
A typical download flow for android11-qpr2-release.
- This will take 40 min. or more to do a clean download depending on the network connection speed & computer performance. To save time, jump to the next step.
```
 mkdir -p $HOME/ws/android
 cd $HOME/ws/android
 repo init -u https://android.googlesource.com/platform/manifest -b android11-qpr2-release
 repo sync -j16
```
For a quickstart, use /ws/android in the codelab1 VM, asd-vm1.
- /ws/android has android11-qpr2-release downloaded in the custom image.
- You don’t need to do this, but just for fun, you may re-sync it. It’ll still take about 4+ min. to sync again. Where repo just compare the logcal projects against to their remote counterparts to see if any update is needed.
```
 cd /ws/android
 repo sync -j16
```

Build sdk_phone_x86_64 AVD

Read Building Android to know more details.
A quickstart to build sdk_phon_x86_64 AVD.
- It may take more than 2 hours to do a Clean Build for an Android device. The build time depends on computer performances, especially on CPU & storage.
- To save time, you can use /ws/android, which is prebuilt with sdk_phone_x86_64-userdebug in /ws/android/out. This is a kind of Incremental Build. It’s much fast, e.g. a few min, because there’s no need to re-build most object files.
- You may even experiment a different disk performance, e.g. by disk size to see how that affect its build time.
- Note: the 1st lunch can take a few min. for each new VM section. ``` echo “Set android folder” export ANDROID_BUILD_TOP=”/ws/android” cd ${ANDROID_BUILD_TOP}

echo “Set up Android build environment” . build/envsetup.sh

echo “Select a target” lunch sdk_phone_x86_64-userdebug

echo “Build the target” m -j16

echo “Run it” emulator &

<img src="res/avd.png" width="400">

## Poke around
Android Emulator provides many useful controls for you to play around with an AVD,
such as:
- [Perform common actions in the emulator](https://developer.android.com/studio/run/emulator#tasks)
- Explore [Extened Control](https://developer.android.com/studio/run/emulator#extended)
- Use [Android Debug Bridge](https://developer.android.com/studio/command-line/adb)
to check the AVD, e.g.

adb devices adb reboot adb shell top ```

Extra credits

Start Android Emulator differently

Start the emulator from the command line.
e.g. try to disable the Quick Boot feature, increase RAM to 4GB & use 6 CPU cores. Check if the AVD runs quicker.
```
  emulator -no-snapshot -memory 4096 -qemu -smp 6 &
```

Install an app

Read Installing an app.
Download a sample app APK from Jetpack Compose Samples to ~/Downloads, e.g. jetsnack-debug.apk.
Install it by adb command-line & start it in the AVD.
```
  adb install $HOME/Downloads/jetsnack-debug.apk
```

Android Images, Partitions & Storages

What are Android Partitions?
What are Android Images?
Even a bit outdated, DIGI provides nice illustrations to connect these concepts.

Changes in Android 11

Source: Android 11 partition structure

Source: DIGI.com: System architecture