Open a command prompt/terminal in your ADB folder.
adb reboot bootloader Your REALME C12 will instantly reboot directly into Fastboot Mode. Some REALME UI versions support this hidden shortcut. It doesn’t always work on every C12 firmware, but it’s worth a try.
Type the following command and press Enter:
If you own a REALME C12 and are looking to unlock the bootloader, flash a custom recovery (like TWRP), or manually install an OTA update, you’ll need to access Fastboot Mode . How to Open Fastboot Mode on REALME C12
Dial the following code exactly:
Press and hold the Volume Up button and the Power button simultaneously.
Power off your REALME C12 completely. Wait 10 seconds to ensure it’s fully shut down. Open a command prompt/terminal in your ADB folder
*#*#20211#*#* or
Continue holding Volume Up until you see a screen with small text or a green android logo. This is Recovery Mode , not Fastboot.
When the REALME logo appears, release the Power button but keep holding Volume Up . It doesn’t always work on every C12 firmware,
adb devices (If your device shows “unauthorized,” check your phone and allow USB debugging access.)
You should now see the Fastboot screen (usually a dark screen with small white text listing your device’s serial number and partition info). This is the easiest method for users who already have USB Debugging enabled.