void init_gdt_entry(size_t num, uint16_t limit, uint32_t base, uint8_t access,
		uint8_t limit_flags)
{
    gdt[num].limit=limit;
    gdt[num].base1=(base & 0xffff);
    gdt[num].base2=(uint8_t)((base & 0xff0000) >> 16);
    gdt[num].access=access;
    gdt[num].limit_flags=limit_flags;
    gdt[num].base3=(uint8_t)((base & 0xff000000) >> 24);
}