pci_irq_route_hdr_t
n = (int)(((pci_irq_route_hdr_t *)hdrp)->pir_size /
((pci_irq_route_hdr_t *)hdrp)->pir_size = n;
((pci_irq_route_hdr_t *)hdrp)->pir_addr = (uint32_t)(uintptr_t)bufp;