firmware_open
if (firmware_open(T4_PORT_NAME, cfg_file, &fw_hdl) != 0) {
if (firmware_open(T4_PORT_NAME, fw_file, &fw_hdl) != 0) {
if ((error = firmware_open("iwn", sc->fwname, &fwh)) != 0) {
extern int firmware_open(const char *, const char *, firmware_handle_t *);