rem: desc->granularity = 1;
add: desc->granularity = 0;
context: set_tss_descriptor(struct segment_descriptor *desc, addr_t base, uint32 limit){	// the TSS descriptor has a special layout different from the standard descriptor	set_segment_descriptor_base(desc, base);	desc->limit_00_15 = (addr_t)limit & 0x0ffff;	desc->limit_19_16 = 0;	desc->type = DT_TSS;	desc->desc_type = DT_SYSTEM_SEGMENT;	desc->privilege_level = DPL_KERNEL;	desc->present = 1;	desc->granularity = 1;	// 4 GB size (in page size steps)	desc->available = 0;	// system available bit is currently not used	desc->d_b = 0;	desc->zero = 0;}