IDXSEL
return (sdp[IDXSEL(sel)].sd_def32 == 0 ? 16 : 32);
sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg);
assert(IDXSEL(sel) != 0);
if (IDXSEL(sel) == 0) {
if (ISLDT(ot_sel) || IDXSEL(ot_sel) == 0) {