pci_conf_hook
int pci_conf_hook(pci_chipset_tag_t, int, int, int, pcireg_t);
int pci_conf_hook(pci_chipset_tag_t, int, int, int, pcireg_t);
int pci_conf_hook(pci_chipset_tag_t, int, int, int, pcireg_t);
int pci_conf_hook(pci_chipset_tag_t, int, int, int, pcireg_t);
confmode = pci_conf_hook(pb->pc, pb->busno,