In layman terms we can say that Fastboot mode is a maintenance mode that is built in the phone for upgrading and diagnostic purpose. This mode is for developers, but if you think you are okay with fiddling with your mobile phone. You should access this particular mode. You can only install firmware, however there is a neat trick. It allows you to access other system modes, but first you need to know how to get into the fastboot mode. Even if you want to get into the recovery mode, you first need to get in the fastboot mode.
The owners of HTC U11 can also enter into fastboot mode on their devices with the following easy-to-do guide for turning your phone on into fastboot mode. The best thing is that you don’t lose your warranty if you boot into this boot. But flashing firmware that are not authorized by HTC will make you lose your warranty. So, we highly recommend not messing with your phone when you are not good with Android protocol layers and computers.
How to enter into Fastboot mode on HTC U11:
Step 2- Download the ADB package, this package depends upon the operating system that you are using. Once downloaded, please extract it anywhere on your computer.
Step 3- Enable the USB debugging mode.
Step 4 – Now you need to open Command prompt window from android-sdk-windows\platform-tools directory. Once you get there, press shift button and click on any empty space in the directory, then open command prompt. This if you are done with Step 1.
Step 5- Now if you did Step 2, you need to go to the place where you extracted the downloaded package and open the command prompt by holding the shift key and right clicking.
Step 6- Type “adb reboot bootloader” into the command window and hit enter.
You may also read: How to Root and Install TWRP on Xperia XA
Step 7- Your phone will get turned off and it will root into the fastboot mode.
If you wish to go back to the normal mode just select the first option. Remember the volume up button acts as selection button while the volume down button is used for navigation.