Is there any way to incorporate different icons, drivers etc. in firmware?

[Android1]

I'm not a noob (well, I think I'm not), I flash and customize phones for a long time, but I always wondered if there is any way to put icons, drivers, elfs, patches etc. in firmware so when I flash phone with that firmware I immediately get different icons and drivers without need to upload them after with some programe

Sorry if someone asked the same question.