4.7. Android OTA

This application note contains steps to test the OTA (Over The Air) feature on Android.

There are 2 ways of applying an OTA update:

1. OTA via adb sideload

2. OTA via Update Engine

4.7.1. OTA via adb sideload

1. Build and flash android images following Build Instructions instructions.

2. Build OTA package

$ cd ${YOUR_PATH}/ti-aosp-14
$ source build/envsetup.sh
$ lunch <BUILD_TARGET>
$ export DIST_DIR=./dist_output
$ m dist

3. Enable adb debugging on your device

4. Reboot to recovery and apply OTA

$ adb reboot sideload
$ adb wait-for-sideload
$ adb sideload $DIST_DIR/am62p-ota-eng.${USER}.zip
$ adb reboot

4.7.2. OTA via Update Engine

1. Build the OTA package

   $ source build/envsetup.sh
   $ lunch <BUILD_TARGET>
   $ export DIST_DIR=./dist_output
   $ m
   $ m dist
   

2. Set your PYTHONPATH.

   Some dependent python modules for gen_update_config.py are part of AOSP tree or part of the build output.

   $ cd $ANDROID_BUILD_TOP
   $ apex_manifest_pb2_path=$(find out -name 'apex_manifest_pb2.py' -print -quit)
   $ PYTHONPATH=$ANDROID_BUILD_TOP/$(dirname ${apex_manifest_pb2_path}):$PYTHONPATH
   $ PYTHONPATH=$ANDROID_BUILD_TOP/build/make/tools/releasetools:$PYTHONPATH
   $ PYTHONPATH=$ANDROID_BUILD_TOP/system/apex/apexer/:$PYTHONPATH
   $ export PYTHONPATH
   

3. Patch the gen_update_config.py script to be compatible with Android 14. In bootable/recovery, apply the following change:

   https://android-review.googlesource.com/c/platform/bootable/recovery/+/2837717

   This can be done with:

   $ cd $ANDROID_BUILD_TOP/bootable/recovery
   $ git fetch https://android.googlesource.com/platform/bootable/recovery refs/changes/17/2837717/1
   $ git cherry-pick FETCH_HEAD
   

4. Update the ota config file. Feel free to change $DIST_DIR to match your developer environment.

   $ source build/envsetup.sh
   $ lunch <BUILD_TARGET>
   $ DIST_DIR=dist_output
   $ BOARD=am62p
   $ bootable/recovery/updater_sample/tools/gen_update_config.py --ab_install NON_STREAMING $DIST_DIR/$BOARD-ota-eng.${USER}.zip $DIST_DIR/$BOARD-ota-eng.${USER}.json file:///data/user/0/com.example.android.systemupdatersample/files/packages/$BOARD-ota-eng.${USER}.zip
   

   Warning

   Be careful, last line is one single very long line.

5. Run the SystemUpdaterSample app once:

   $ adb root
   $ adb shell setenforce 0
   $ adb shell am start com.example.android.systemupdatersample/com.example.android.systemupdatersample.ui.MainActivity
   

6. Push the files on the board:

   $ adb root
   $ adb shell mkdir /data/user/0/com.example.android.systemupdatersample/files/configs
   $ adb shell mkdir /data/user/0/com.example.android.systemupdatersample/files/packages
   $ adb push $DIST_DIR/$BOARD-ota-eng.${USER}.json /data/user/0/com.example.android.systemupdatersample/files/configs/
   $ adb push $DIST_DIR/$BOARD-ota-eng.${USER}.zip /data/user/0/com.example.android.systemupdatersample/files/packages/
   

7. Change SELinux label:

   $ adb shell chcon -R u:object_r:ota_package_file:s0 /data/user/0/com.example.android.systemupdatersample/
   

8. Change Unix permisssions:

   $ adb shell chmod -R 777 /data/user/0/com.example.android.systemupdatersample/
   

9. Run the update on the UI:

   • Tap on RELOAD to load the config

   • Tap on APPLY to apply the OTA

   • Tap OK to confirm application

   • Wait for progress bar to complete

   • Tap on SWITCH SLOT to finish update (scroll downwards to see the button)

   • Wait for verification

10. Reboot the device with:

    $ adb shell svc power reboot
    

11. Confirm that booting on slot b

    $ adb root
    $ adb shell grep -o 'androidboot.slot_suffix=[_ab]*' /proc/cmdline
    androidboot.slot_suffix=_b
    

4.7.2.1. Troubleshooting

Python 3.12 is not supported, because it removed the imp module and also comes with a too recent version of protobuf.

To install and older version, use virtualenv:

$ pip install virtualenv # make sure python3.11 is installed on your system
$ virtualenv --py 3.11 venv_ota_build

$ source venv_ota_build/bin/activate
$ pip install protobuf==3.20

From here, you should be able to invoke gen_update_config.py.