通过中断门访问内核

象全局描述符表GDT一样，在整个系统中，中断描述符表IDT只有一个。中断描述符表寄存器IDTR指示IDT在内存中的位置。由于80386只识别256个中断向量号，所以IDT最大长度是2K。

中断描述符表IDT所含的描述符只能是中断门、陷阱门和任务门。也就是说，在保护模式下，80386只有通过中断门、陷阱门或任务门才能转移到对应的中断或异常处理程序。

-By interrupt doors to access the kernel

Like the Global Descr iptor Table GDT in the entire system, only one interrupt descr iptor table IDT. Interrupt descr iptor table register IDTR indicates the location of the IDT in memory. Identify 256 interrupt vector number 80386, the maximum length of the IDT is 2K.

　　Descr iptor interrupt descr iptor table IDT contained only interrupt gate, trap gate, and task gate. In other words, in protected mode, the 80386 only through interrupt doors, the trap door, or tasks door to transfer to the corresponding interrupt or exception handler.