How to change screen resolution in Kernel source? (Android 4.2.2 JB on BBB, OS Provider -> TI)


I wanna use my 7inc hdmi touch screen

but my board’s screen resolution is not fine.

i did search and find one solution : Change kernel of your OS

but i don’t know WHERE and HOW can i change…

i read All guides on TI page. but there is no solution what i need

plz let me know where and how to change.

thank you.