mkclock_hb_attach
static void mkclock_hb_attach(device_t, device_t, void *);
mkclock_hb_match, mkclock_hb_attach, NULL, NULL);
void mkclock_hb_attach(device_t, device_t, void *);
mkclock_hb_match, mkclock_hb_attach, NULL, NULL);