ra_intr_establish
rtsc->sc_ih = ra_intr_establish(rtsc->sc_irq, comintr, sc, 1);
sc->sc_ih = ra_intr_establish(RA_IRQ_USB, ehci_intr, sc, 1);
sc->sc_ih = ra_intr_establish(RA_IRQ_FENGINE,
sc->sc_ih = ra_intr_establish(RA_IRQ_PIO,
ra_intr_establish(RA_IRQ_HIGH, ra_pic_intr,
ra_intr_establish(RA_IRQ_LOW, ra_pic_intr,
sc->sc_ih = ra_intr_establish(RA_IRQ_USB, ohci_intr, sc, 0);
extern void *ra_intr_establish(int, int (*)(void *), void *, int);
sc->sc_ih = ra_intr_establish(RA_IRQ_TIMER0, ra_wdog_timer0, sc, 0);