How do i upgrade the delstar ds 4327?

Question

there are these great players with firmware upgrades for the player and i am wondering if there is anyway of upgrading this player with opensource. There is nothing on the delstar technologies page, and from the serial on the back of the player i am thinking this is a chinese chipset that will work with some of these opensource alternatives with an exception to rockbox. i want to emulate nes to work with the five button interface what do you think?