Download Link Walton Primo D1 Firmware - Flash File Link
sometime your smart phone operating system is Corrupted. when you turn on your smart phone only show Walton logo on screen.
your smart phone is slowly working sometime device is stuck phone is restart without any region. when you try make a call phone is turn off. if you open any application device freezing or any other flashing related problem you can fix it after complete flashing.
if your device virus attack, download automatic application and install it or any others flashing problem you can fix it after flashing .