Bootloader unlock

On the greater part of Android tablets and phones, you can unlock bootloader and then lock it by using the command line.

These are the things you need to unlock bootloader:

PC with operating system Windows 7 +
Installed drivers for your phone
Fully charged battery
Reliable USB cable to connect your phone to a PC
Enabled “OEM Unlock” in the developer options (not for all devices)

ATTENTION! On some devices, bootloader unlock may reset your settings!

Make sure that all of your important files and data are saved!

Bootloader unlock guide

Having prepared the above, you can start the process of bootloader unlock:

Download and unzip ADB & Fastboot on your computer
Open the settings for developers and activate the “USB debugging”
Connect your phone to your computer (when you first connect your phone, you will be asked to allow debugging from this PC, confirm it)
Open the folder with adb, right-click the mouse pressing Shift key, select “Open command window”
Type the command adb reboot fastboot (if the phone just rebooted – you can use the command adb reboot bootloader)
After booting into the fastboot mode, enter the command fastboot oem unlock and press Enter
Type the command fastboot reboot

Done! Now you know how to unlock the bootloader using the command line! If you want to lock bootloader – flash official firmware and then lock it by instruction above, just use command “fastboot oem lock” instead “fastboot oem unlock”.

Bootloader mode

The bootloader mode is the first and possibly the most important part of the Android OS. The loader, as the name implies, loads the boot image, scans the entire system for errors and custom parts. Some of them can be corrected without user intervention, and some require attention.

When you boot a device in the bootloader mode it gives you the opportunity to choose where system will go:

System
Recovery mode
Fastboot mode
Other modes

And now is the main question: “Why you need to know what is bootloader mode and why is it neccessary to unlock it?”. As I said earlier, bootloader scan system for a custom software, so if you want to install any custom rom or even custom recovery – you need to disable this check, or device will not boot, or will be factory reseted.

To disable bootloader check, you just need to unlock it. Be careful, the unlocked bootloader can lead to a loss of warranty!

What is Developer Options Mode

Want to know what is developer mode in Android? So, Android 6 Marshmallow has nine categories of developer options. Developer options on Android which contain 47 different functions altogether:

General
Debugging
Networking
Input
Drawing
Hardware accelerated rendering
Media
Monitoring
Apps

If you know more information about these options and can answer such questions like “What can I do with developer options? What is developer options in Android? or What does an Android developer do?”, share your experiences with us in comments below the article.

Don’t forget, that you are making all the changes in Developer mode on your own risk! So learn the topic “What is developer mode in Android?” very carefully.

Android developer mode and what can you do with it

Android Developer Mode Options – General Overview:

Take a bug report of developer mode features for the Android phone: Tapping this option grabs the current log files on your device, packages them up and prepares them for sending to whoever you want to have it
Desktop backup password that you can put in the Android phone in the developer mode: ADB backup and restore apps and their respective data from your device. You can set a password for those backups, so that they can’t be restored without it
Stay awake with Android device developer mode: by switching on this option you enable your mobile phone screen to stay on every time you plug it in. It is better not use this function of Android developer mode without a special need, otherwise the images will burn into the screen (possible)
Enable Bluetooth HCI snoop log: enabling this function among developer mode extensions you will place Bluetooth HCI (Host Controller Interface) packets on the device storage (/sdcard/btsnoop_hci.log) for retrieval. You can then analyze the information with a program like Wireshark
Running services: this feature shows everything you need to know about the running services on your smartphone

But first of all, it also will be useful for you to find out how to enter developer mode on Android and how to exit developer mode on Android.