SCB_IOVECBASE
if (vec < SCB_IOVECBASE || vec >= SCB_SIZE ||
idx = SCB_VECTOIDX(vec - SCB_IOVECBASE);
vec >= SCB_IOVECBASE; vec -= SCB_VECSIZE) {
idx = SCB_VECTOIDX(vec - SCB_IOVECBASE);
if (vec < SCB_IOVECBASE || vec >= SCB_SIZE ||
idx = SCB_VECTOIDX(vec - SCB_IOVECBASE);
KDASSERT(a1 >= SCB_IOVECBASE && a1 < SCB_SIZE);
scb = &scb_iovectab[SCB_VECTOIDX(a1 - SCB_IOVECBASE)];
struct scbvec scb_iovectab[SCB_VECTOIDX(SCB_SIZE - SCB_IOVECBASE)];
#define SCB_NIOVECS SCB_VECTOIDX(SCB_SIZE - SCB_IOVECBASE)