6、王爽《汇编语言》笔记_实验8

程序分析

assume cs:codesgcodesg segment    mov ax,4c00h    int 21hstart: mov ax,0            ax=0    s: nop                 占一字节,机器码90       nop                 占一字节,机器码90       mov di,offset s     (di)=s偏移地址       mov si,offset s2    (si)=s2偏移地址       mov ax,cs:[si]      (ax)=jmp short s1指令对应的机器码EBF6       mov cs:[di],ax      jmp short s1覆盖s处指令2条nop指令   s0: jmp short s         执行s???? 未执行到这里，直接跳回mov ax,4c00h了   s1: mov ax,0       int 21h       mov ax,0   s2: jmp short s1              nopcodesg endsend start