segment_descriptor
struct segment_descriptor *sd;
setsegment(struct segment_descriptor *sd, const void *base, size_t limit,
struct segment_descriptor sd;
struct segment_descriptor pcb_fsd; /* %fs descriptor */
struct segment_descriptor pcb_gsd; /* %gs descriptor */
struct segment_descriptor sd;
void setsegment(struct segment_descriptor *, const void *, size_t, int, int,
#define SDTYPE(p) (((const struct segment_descriptor *)(p))->sd_type)
sizeof(struct segment_descriptor));
sizeof(struct segment_descriptor));
struct segment_descriptor *sd;