void rivafb_imageblit (struct fb_info * info, const struct fb_image * image);
If the source is a monochrome bitmap, the function fills up a a region of framebuffer memory with pixels whose color is determined by the bit setting of the bitmap, 1 - foreground, 0 - background.
If the source is not a monochrome bitmap, color expansion is not done. In this case, it is channeled to a software function.
framebuffer hook