NIOS II and VGA graphics chip

I'm trying to use an external graphics chip with a NOIS II core. I have tried using a Lancelot board with a 2D graphics core and whilst this works just fine the load the graphics places on the NIOS II processor is unacceptable. As an alternative I'm looking at adding an ATI RAGE XL graphics chip. The main problem is that not having an X86 BIOS then initalising the graphics chip is an issue. ATI have BIOS available for x86, PPC and MIPS processors but nothing for a NIOS II - any suggestions as to how this can be done?