PCI_CB_IOBASE1
sc->sc_iobase[1] = pci_conf_read(pc, tag, PCI_CB_IOBASE1);
pci_conf_write(pc, tag, PCI_CB_IOBASE1, sc->sc_iobase[1]);
pci_conf_write(pc, tag, PCI_CB_IOBASE1, 0xffffffff);