Building the image on a Google Pixel C tablet

Prerequisites:

Install cocos2d-x according to the procedure listed at http://www.cocos2d-x.org/docs/installation/Android-terminal/
In the Android SDK:
- Edit sdk/tools/ant/build.xml
- Uncomment the below line:
  
  
  
  and change it to
  
  <nocompress extension="webm" />
Prepare a Google Pixel C tablet with 6.0.1 Android version and unlocked boot loader

Build steps

cd goa
cocos run -p android -m release

The apk will be generated at goa/publish

Generating the userdata.img for flashing to Google Pixel C tablet

In a shell on a Mac or Linux PC, in a user writeable directory, create a directory called my_userdata, with a subdirectory called app.
Copy your APK(s) to the app directory
sudo make_ext4fs -l 30720M -s -a userdata ./userdata.img my_userdata

...where 10240M is the size you want your partition to be.

NOTE: Do not include directories other than the "app" directory.
fastboot flash userdata userdata.img