Successfully installed TWRP and Magisk means bootloader unlocked? I have a Samsung Galaxy On7, running stock firmware, Android 6.0.1. I have successfully installed TWRP and also flashed Magisk. In the developer options, I have toggled the "OEM Unlock" option to ON position.

I was reading that in order to flash a custom ROM like Lineage OS, I have to unlock the bootloader. There are a number of methods to check if the bootloader is unlocked, viz. one from fastboot and one by dialling certain commands in the phone dialer. Unfortunately, fastboot cannot recognise my device in Download mode, and the dialler commands are not working too.

I read somewhere that toggling the OEM Unlock option to ON means my bootloader is ulocked. Is that true? Having been able to successfully install TWRP and Magisk, can I conclude that my bootloader is unlocked?
Install Google's ADB drivers, connect your phone to your PC, open a command prompt and type:

adb reboot bootloader


Then:

fastboot oem device-info


And you will see the bootloader's status, either in the command prompt or on the device's screen.

To unlock a locked bootloader, type:

fastboot oem unlock


Remember that unlocking the bootloader will wipe all of your user data, as a factory reset does. Backup your data first.



Since you have a Samsung phone, remember that Fastboot isn't supported, while Odin is. To unlock the bootloader, simply find the OEM unlock entry in the device's settings and enable it.