Hard key isn't working in XOS ROM. Need Help!

[Rafiul Bari Chowdhury]

Hardware Key (Back button, Home Button Etc) isn't working after replacing 'usr/keylayout/generic.kl' in XOS ROM. I aslo tried to fix this bug replacing whole 'usr folder' in /system! But it didn't work. Is there anyway to fix?
I'm using Mtk6580 with Kernel version 3.18.19