Installing the bootloader

If you are on Android 9, you will need to update to Android 11 or LineageOS 19.1 first

To install the MicroSD compatible bootloader on Android 11:

1. Unzip the microsd_bootloader_install_pocket2plus_stock11.zip file.
2. Plug your Retroid Pocket 2+ in to your computer and select File transfer on the Use USB for prompt on the Retroid Pocket 2+.
3. Copy the contents of the unzipped file (boot.img, flash_microsd_bootloader.sh, restore_stock_bootloader.sh, and vbmeta.img) to Internal shared storage. Do not put it in any sub-folder
4. On your Retroid Pocket 2+, open Settings -> Handheld Settings -> Advanced -> Run script as Root and click Select a Script.
5. In the file chooser dialog, navigate to Retroid Pocket 2+ and select flash_microsd_bootloader.sh
6. In the dialog asking whether you want to run flash_microsd_bootloader.sh, click Run.
7. The flashing process will likely take close to a minute. Do not press any buttons or turn off the device until it is finished.
8. Once you seet Run Script Completed, the install has finished.

To install the MicroSD compatible bootloader on LineageOS 19.1:

1. Install the latest LineageOS build using the built-in Updater in Settings. The bootloader is included in the lastest update.

Uninstalling the bootloader

To uninstall the MicroSD compatible bootloader on Android 11:

1. Follow the same steps as installation, but run restore_stock_bootloader.sh instead.

To uninstall the MicroSD compatible bootloader on LineageOS 19.1:

1. There is no need to uninstall it, since it does not impact OTA updates.

Creating bootable MicroSD cards

To create a bootable MicroSD card:

1. Format it with an exfat filesystem
2. Create a boot folder on it
3. Copy an OS init script of choice into the boot folder (ex. GarlicOS)
4. Extract an OS rootfs file of choice into the boot folder with 7zip (ex. GarlicOS)

Booting bootable MicroSD cards

To boot a bootable MicroSD card:

1. Make sure your device is powered off and not plugged in
2. Hold down the power button and volume-up button at the same time
3. Let go of both buttons once the Retroid logo is visible on screen. The device should not vibrate if done correctly