smfb_cnattach
int smfb_cnattach(bus_space_tag_t, bus_space_tag_t, pcitag_t, pcireg_t);
rc = smfb_cnattach(early_mem_t,
extern int smfb_cnattach(bus_space_tag_t, bus_space_tag_t, pcitag_t, pcireg_t);