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Preparing Your Device#

Verify that you can backup and restore your device and that you understand device recovery options. This is not only useful when flashing images you build with this guide, but also in case you want to reset your device to its factory state with stock Android (note that not all Android vendors provide factory images for download, so you might need to create a full backup of your running Android system and store it in a safe place before starting to erase and reflash the device with your custom builds).

Backup and Verify Your Device#

As mentioned above, it might be helpful to backup the existing stock Android image before flashing the Android base release for the first time, as obtaining the stock image might be hard for some vendors (e.g. some stock images are only available as self-extracting .exe package for Windows) or impossible (some vendors do not provide stock images for download).

Use Android Recovery (e.g. TWRP or ClockworkMod) to:

  1. Backup to SD card: system, data, boot and recovery partitions
  2. Test restoring the backup (important)

Warning

While backing up to internal device storage is possible for some devices, if during porting you end up overwriting that partition, your backups will be gone. In that case (and in case of devices without SD card slots), it's better to also copy the backup data to your development machine (e.g. via adb pull in recovery). Recent versions of adb support full-device backups to a host computer using the adb backup feature.

See the ClockworkMod Instructions for additional help.

Flash and Test your Android base image#

Flash an image that you built or obtained of your Android base, whether it's LineageOS, CAF, AOSP, or another.

The official LineageOS flashing instructions can be found on this LineageOS wiki page.

You may also want to verify that the Android base build for your device is fully functional, to avoid wasting time with hardware adaptations that have known issues. Also, your device might have some hardware defects - testing in Android verifies that all components are working correctly, so you have a functionality baseline to compare your Sailfish OS build results with.

You should at least check the following features:

  • OpenGL ES 2.0: Use e.g. Gears for Android to test (the hz you will get there will be max refresh rate).
  • WLAN connectivity: Connect to an AP, ad-hoc or set up a mobile access point with your device.
  • Audio: Headset detection, earpiece speaker, loudspeakers, etc.
  • Bluetooth: Connect to bluetooth headsets, verify discoverability, send files.
  • NFC: Check if NFC tags can be detected, read and/or written by the device.
  • SD/MicroSD: Use a file manager app to see if inserted SD cards can be detected.
  • USB: MTP, mass storage (if available) and adb access.
  • Telephony: 2G/3G/LTE calls + data connectivity.
  • GPS: Using GPS Test, check GLONASS too; typical time to fix; AGPS.
  • Sensors: Using AndroSensor: Accelerometer, Proximity Sensor, Ambient Light Sensor, Gyroscope, Magnetometer (Compass), Hall (flip case), ...
  • LEDs: If your device has notification LEDs or keypad backlights.
  • Camera (front and back): Also test functionality of zoom, flash, etc..
  • Buttons: Volume up, volume down, power, camera shutter, etc..
  • Video out: HDMI / MHL connectivity if you have the necessary adapters. TV out.
  • Screen backlight: Suspend and backlight control, minimum and maximum brightness.
  • Battery meter: Charge level, battery health, charging via USB (wall charger and host PC).
  • Vibration motor: Intensity, patterns.

  • HW composer version: check dumpsys SurfaceFlinger through ADB (see SF Layer Debugging).

  • Fingerprint sensor

  • FM Radio

We recommend that you write down the results of these tests, so you can always remember them.