CLUT_DATA
i810_writeb(CLUT_DATA, mmio, red);
i810_writeb(CLUT_DATA, mmio, green);
i810_writeb(CLUT_DATA, mmio, blue);
*red = i810_readb(CLUT_DATA, mmio);
*green = i810_readb(CLUT_DATA, mmio);
*blue = i810_readb(CLUT_DATA, mmio);