adb devices You should see your device serial number with “device” next to it.
Now reboot to bootloader:
But one day, a critical security patch arrives. You can’t install it normally. You have to re-lock the bootloader — which requires flashing stock firmware first. That’s another story.
adb reboot bootloader The phone screen goes black, then shows the screen — a tiny white text on a black background. Unlock Bootloader Nokia 3.4
For now, you hold an unlocked device in your hands, and the possibilities are endless.
fastboot oem device-info Output should show: (bootloader) Device unlocked: true
The gatekeeper to this freedom is the . Nokia (HMD Global), unlike Google Pixels or OnePlus devices, does not officially provide an unlock method for most of its phones. The Nokia 3.4 is no exception. But the modding community found a backdoor — an unofficial exploit via a tool called Nokia Bootloader Unlock . adb devices You should see your device serial
Verify fastboot connection:
To verify: Reboot to bootloader again and type:
On your PC, open a command prompt in the platform-tools folder and type: You have to re-lock the bootloader — which
fastboot devices Again, your device serial appears. Good. Most Nokia phones would stop here, showing fastboot oem unlock as “not allowed”. But your Nokia 3.4 has a secret: an engineering bootloader exploit.
Use volume keys to highlight “UNLOCK THE BOOTLOADER” and press power button to confirm.