If you are using a Linux or a similar operating system on your PC or Mac chances are very high that you already have these two applications installed. Open a terminal and exectute the following commands.
adb version
fastboot --version
If one or both of these output an error you need to (re-)install adb and fastboot.
wget https://dl.google.com/android/repository/platform-tools-latest-linux.zip
unzip platform-tools-latest-linux.zip -d ~
Update your PATH variable for your environment
gedit ~/.profile
Add the following
# add Android SDK platform tools to path
if [ -d "$HOME/platform-tools" ] ; then
PATH="$HOME/platform-tools:$PATH"
fi
Then update your environment
source ~/.profile
Download the latest version of adb and fastboot to a directory of your choice and extract the archive.
Note: I've had reports that under Windows adb/fastboot might not recognize the phone while in TWRP. For now I don't know whats causing this. So if that happends to you try using linux instead.
To be able to install anything on the Unihertz Jelly2 we first need to unlock the bootloader.
- Boot your device into the official OS.
- Go to
Settings > About phone
, tap the "build number" several times to enable developer settings. - Go to
Settings > System > Developer Settings
, enable OEM unlocking and ADB debugging. - Connect your phone to your PC and open a terminal or a command line window.
- Run
adb reboot bootloader
on your PC (there is no way to enter bootloader directly, only possible through adb). - Once your device has finished booting run
fastboot flashing unlock
and comfirm unlock on device (THIS WILL WIPE ALL DATA!). - Run
fastboot reboot
to reboot your device and now you should see an unlocked warning during boot screen.
To get LineageOS to boot proberly we also need to disable AVB. Otherwise the bootloader will check the ROM with the wrong authorization keys and prevent the loading.
- Download
vbmeta.img
from the latest release page of your device. - Connect your phone to your PC and open a terminal or a command line window.
- Run
adb reboot bootloader
on your PC to put your device in bootloader mode. - Once your device has finished booting run
fastboot flash --disable-verification --disable-verity vbmeta vbmeta.img
. - Then run
fastboot flash --disable-verification --disable-verity vbmeta_system vbmeta.img
. - Also run
fastboot flash --disable-verification --disable-verity vbmeta_vendor vbmeta.img
.
- Download
recovery.img
from the latest release page of your device. - Connect your phone to your PC and open a terminal or a command line window.
- Run
adb reboot bootloader
on your PC to put your device in bootloader mode. - Once your device has finished booting run
fastboot flash recovery recovery.img
. - Run
fastboot reboot
and after the screen goes dark press volume up until you see the TWRP logo. - Now you need to install a new ROM because booting into stock ROM will replace TWRP with the stock recovery.
- Download
lineage-17.1-XXX-UNOFFICIAL-YYY.zip
from the latest release page of your device. - Connect your phone to your PC and open a terminal or a command line window.
- Run
adb reboot recovery
on your PC or simply hold volume up while turning power on to boot your device into the recovery. - In TWRP select
Wipe > Advanced Wipe
. - Tick
Dalvik / ART Cache
,Cache
,Data
,Internal Storage
. - Swipe the slider on the bottom to the right to confirm. (THIS WILL WIPE ALL DATA!)
- From home screen select
Advanced > ADB Sideload
. - Swipe the slider on the bottom to the right to confirm.
- Run
adb sideload lineage-17.1-XXX-UNOFFICIAL-YYY.zip
from your PC. - Wait for the process to finish. The recovery might prompt something about verification failure, just ignore it and continue anyway.
- Run
adb push lineage-17.1-XXX-UNOFFICIAL-YYY.zip /external_sd
on your PC or transfer the file beforehand onto your SD card. - From home screen select
Install
. - Use
Select Storage
to switch to your SD card. - Select the previously transfered file.
- Swipe the slider on the bottom to the right to confirm.
- (Optional) At this point, you can then install the latest Magisk and/or OpenGAPPS Nano at your will. Note that the size of the system partition might only be enough for the "nano" variant of OpenGAPPS. If installing Magisk / OpenGAPPS fails, you can try rebooting into recovery again in advanced menus, then try installing them again.
- Select
Reboot System
to reboot into LineageOS and enjoy. Note that Magisk might cause your device to boot loop once or twice but it will eventually boot.