GUGS_SEL
gdt_segs[GUGS_SEL].ssd_limit = atop(0 - 1);
td->td_pcb->pcb_gs = GSEL(GUGS_SEL, SEL_UPL);
td->td_pcb->pcb_gs = GSEL(GUGS_SEL, SEL_UPL);
load_gs(GSEL(GUGS_SEL, SEL_UPL));
load_gs(GSEL(GUGS_SEL, SEL_UPL));
td->td_pcb->pcb_gs = GSEL(GUGS_SEL, SEL_UPL);
load_gs(GSEL(GUGS_SEL, SEL_UPL));