PCIR_INTPIN
pci_set_cfgdata8(pi, PCIR_INTPIN, 0x1);
pci_set_cfgdata8(pdi, PCIR_INTPIN, 0);
pci_set_cfgdata8(pi, PCIR_INTPIN, bestpin + 1);
intpin = pci_get_cfgdata8(pi, PCIR_INTPIN);
pci_set_cfgdata8(pi, PCIR_INTPIN, intpin);
uint8_t intpin = passthru_read_config(sc, PCIR_INTPIN, 1);