Android: How to add Pre-loaded Application?

I have been trying to make my application a pre-loaded application on the Android OS Kernel. Within these two makefiles: generic.mk and core.mk, I added my application to the list of pre-loaded applications found under PRODUCT_PACKAGES:=, but when I load my custom kernel my application 开发者_如何学运维is not installed. Am I doing something wrong?

I resolved this issue by flashing the system.img along with the boot.img