gscps2_readb_status
while (gscps2_readb_status(addr) & GSC_STAT_TBNE) {
while (gscps2_readb_status(ps2port->addr) & GSC_STAT_RBNE)
while (gscps2_readb_status(addr) & GSC_STAT_RBNE)
status = gscps2_readb_status(ps2port->addr);
if (gscps2_readb_status(ps2port->addr) & GSC_STAT_CMPINTR)