[LinuxBIOS] VGA on gx2/cs5535??

[lihao]

Hi all,
My platform is gx2 plus cs5535. I have loaded VSA image. It can boot to
payload if I don't add VGA support. Now I want to add VGA, do I need to
make a VGA image from Linux myself? cause I notice that if I use VSA,
graphics_init() just contains a vrWrite routine which just call VSA
code, right?
If it needs making VGA image myself, where to put VGA image in flash?
How to call it?? From code flow I cannot see clearly how VGA is called
if there is do_vsmbios.

Regards,
Hao Li