Always use x86 emulators (or x86_64 for testing 64-bit APKs). Although arm emulators exist, they are so slow that they are not worth your time.
*** note Note: apps with native code must be compiled specifically for the device architecture, so make sure your copy of the app supports x86. Also, be aware the Play Store may not display ARM-only applications for an x86 emulator. The steps below show how to locally compile chromium-based apps for x86.
You need to target the correct architecture via GN args:
target_cpu = "x86" # or "x64" if you have an x86_64 emulator
By far the easiest way to set up emulator images is to use Android Studio. If you don't have an Android Studio project already, you can create a blank one to be able to reach the Virtual Device Manager screen.
Refer to: https://developer.android.com/studio/run/managing-avds.html
Where files live:
- System partition images are stored within the sdk directory.
- Emulator configs and data partition images are stored within
~/.android/avd/
.
Choose a skin with a small screen for better performance (unless you care about testing large screens).
Android Studio's image labels roughly translate to the following:
AVD "Target" | Virtual Device Configuration tab | GMS? | Build Properties |
---|---|---|---|
Google Play | "Recommended" (the default tab) | This has GMS | user /release-keys |
Google APIs | "x86 Images" | This has GMS | userdebug /dev-keys |
No label | "x86 Images" | AOSP image, does not have GMS | eng /test-keys |
*** promo Tip: if you're not sure which to use, choose Google APIs under the x86 Images tab in the Virtual Device Configuration wizard.
"Show Advanced Settings" > scroll down:
- Set internal storage to 4000MB (component builds are really big).
- Set SD card to 1000MB (our tests push a lot of files to /sdcard).
- Our test & installer scripts do not work with pre-MR1 Jelly Bean.
- Component builds do not work on pre-KitKat (due to the OS having a max number of shared libraries).
- Jelly Bean and KitKat images sometimes forget to mount /sdcard :(.
- This causes tests to fail.
- To ensure it's there:
adb -s emulator-5554 shell mount
(look for /sdcard) - Can often be fixed by editing
~/.android/avd/YOUR_DEVICE/config.ini
.- Look for
hw.sdCard=no
and set it toyes
- Look for
Running tests on two emulators is twice as fast as running on one. Rather than use the UI to create additional avds, you can clone an existing one via:
$ tools/android/emulator/clone_avd.py \
--source-ini ~/.android/avd/EMULATOR_ID.ini \
--dest-ini ~/.android/avd/EMULATOR_ID_CLONED.ini \
--display-name "Cloned Emulator"
Refer to: https://developer.android.com/studio/run/emulator-commandline.html.
*** promo Ctrl-C will gracefully close an emulator.
$ ~/Android/Sdk/emulator/emulator @EMULATOR_ID
You can run an emulator without creating a window on your desktop (useful for
ssh
):
$ ~/Android/Sdk/emulator/emulator -no-window @EMULATOR_ID
Unlike physical devices, an emulator's /system
partition cannot be modified by
default (even on rooted devices). If you need to do so (such as to remove a
system app), you can start your emulator like so:
$ ~/Android/Sdk/emulator/emulator -writable-system @EMULATOR_ID
For better graphics performance, use virtualgl (Googlers, see http://go/virtualgl):
$ vglrun ~/Android/Sdk/emulator/emulator @EMULATOR_ID
- Emulators show up just like devices via
adb devices
- Device serials will look like "emulator-5554", "emulator-5556", etc.