posibble to boot backup w/o modchip ?

[diz.mx]

Hi, I'm new here, I don't even got PS2, my friend have and asked me to help him.

Ok, to the point:
Is it possible to boot backups (and will they need be patched) without modchip. My friend have AR2 and he don't wanna modify PS2.

Probbably this question was answered before but I don't have time to search for it.