LLDT - Load Local Descriptor Table Register
0F 00 /2         LLDT r/m16         Load segment selector r/m16 into LDTR

Description
Loads the source operand into the segment selector field of the local descriptor table register (LDTR). The source operand (a general-purpose register or a memory location) contains a segment selector that points to a local descriptor table (LDT). After the segment selector is loaded in the LDTR, the processor uses to segment selector to locate the segment descriptor for the LDT in the global descriptor table (GDT). It then loads the segment limit and base address for the LDT from the segment descriptor into the LDTR. The segment registers DS, ES, SS, FS, GS, and CS are not affected by this instruction, nor is the LDTR field in the task state segment (TSS) for the current task.

If the source operand is 0, the LDTR is marked invalid and all references to descriptors in the LDT (except by the LAR, VERR, VERW or LSL instructions) cause a general protection excep-tion (#GP).

The operand-size attribute has no effect on this instruction.

The LLDT instruction is provided for use in operating-system software; it should not be used in application programs. Also, this instruction can only be executed in protected mode.

金山词霸：  

把源操作数载入这个LDTR的段选择子
这个包含源操作数的段选择子用于指明局部描述符LDT
在这个段选择子被载入LDTR后
处理器就通过这个段选择子来定位GDT中LDT的地址
然后载入LDTR中用来描述LDT的限长和基址
其他段选择子和在任务状态段中的LDTR区不受影响
如果源操作数为0，LDTR寄存器被标记位无效，所有引用的LDT描述符会出现一个通用保护异常

我想问的是源操作数是哪来的  是什么改变了LDTR 从而确定LDT的位置的

LDTR中属于高速缓存区的的基址和限长是哪来的

怎么没人回答啊 多少给点提示啊

不小心回了2条了

不错 过来学习下 哈哈