https://wenyiblog.top/tags/i/o/ Recent content in I/O on 文艺技术笔记 Hugo -- gohugo.io zh 文艺技术笔记 | 软件工程师文艺 Sat, 13 Jun 2026 11:00:00 +0800 https://wenyiblog.top/2026/06/asm-14-io-interrupts/ Sat, 13 Jun 2026 11:00:00 +0800 https://wenyiblog.top/2026/06/asm-14-io-interrupts/ <h2 id="io-端口"><a href="#io-%e7%ab%af%e5%8f%a3" class="header-anchor"></a>I/O 端口 </h2><p>CPU 通过端口与外设通信。x86 有独立的 I/O 地址空间（64KB）。</p> <h2 id="端口读写指令"><a href="#%e7%ab%af%e5%8f%a3%e8%af%bb%e5%86%99%e6%8c%87%e4%bb%a4" class="header-anchor"></a>端口读写指令 </h2><div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code><span class="lnt">1 </span><span class="lnt">2 </span></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback"><span class="line"><span class="cl">IN AL, DX ; 从 DX 指向的端口读入 AL </span></span><span class="line"><span class="cl">OUT DX, AL ; 将 AL 写入 DX 指向的端口 </span></span></code></pre></td></tr></table> </div> </div><h2 id="中断向量表ivt"><a href="#%e4%b8%ad%e6%96%ad%e5%90%91%e9%87%8f%e8%a1%a8ivt" class="header-anchor"></a>中断向量表（IVT） </h2><p>内存 <code>0000:0000</code> 处的 1KB 空间，存放 256 个中断处理程序地址：</p> <table> <thead> <tr> <th style="text-align:left">中断号</th> <th style="text-align:left">功能</th> </tr> </thead> <tbody> <tr> <td style="text-align:left"><strong>00h</strong></td> <td style="text-align:left">除零错误</td> </tr> <tr> <td style="text-align:left"><strong>08h</strong></td> <td style="text-align:left">定时器中断</td> </tr> <tr> <td style="text-align:left"><strong>09h</strong></td> <td style="text-align:left">键盘中断</td> </tr> <tr> <td style="text-align:left"><strong>10h</strong></td> <td style="text-align:left">BIOS 显示服务</td> </tr> <tr> <td style="text-align:left"><strong>13h</strong></td> <td style="text-align:left">BIOS 磁盘服务</td> </tr> <tr> <td style="text-align:left"><strong>21h</strong></td> <td style="text-align:left">DOS 系统调用</td> </tr> </tbody> </table> <h2 id="中断处理流程"><a href="#%e4%b8%ad%e6%96%ad%e5%a4%84%e7%90%86%e6%b5%81%e7%a8%8b" class="header-anchor"></a>中断处理流程 </h2><ol> <li>CPU 收到中断请求</li> <li>保存 FLAGS、CS、IP 到栈</li> <li>从 IVT 查找处理程序地址</li> <li>跳转到处理程序</li> <li><code>IRET</code> 返回</li> </ol> <h2 id="自定义中断处理程序"><a href="#%e8%87%aa%e5%ae%9a%e4%b9%89%e4%b8%ad%e6%96%ad%e5%a4%84%e7%90%86%e7%a8%8b%e5%ba%8f" class="header-anchor"></a>自定义中断处理程序 </h2><div class="highlight"><div class="chroma"> <table class="lntable"><tr><td class="lntd"> <pre tabindex="0" class="chroma"><code><span class="lnt"> 1 </span><span class="lnt"> 2 </span><span class="lnt"> 3 </span><span class="lnt"> 4 </span><span class="lnt"> 5 </span><span class="lnt"> 6 </span><span class="lnt"> 7 </span><span class="lnt"> 8 </span><span class="lnt"> 9 </span><span class="lnt">10 </span><span class="lnt">11 </span><span class="lnt">12 </span><span class="lnt">13 </span><span class="lnt">14 </span><span class="lnt">15 </span></code></pre></td> <td class="lntd"> <pre tabindex="0" class="chroma"><code class="language-fallback" data-lang="fallback"><span class="line"><span class="cl">; 安装自定义中断 </span></span><span class="line"><span class="cl">CLI ; 关中断 </span></span><span class="line"><span class="cl">MOV AX, 0 </span></span><span class="line"><span class="cl">MOV ES, AX </span></span><span class="line"><span class="cl">MOV WORD PTR ES:[09h*4], OFFSET MyISR </span></span><span class="line"><span class="cl">MOV WORD PTR ES:[09h*4+2], CS </span></span><span class="line"><span class="cl">STI ; 开中断 </span></span><span class="line"><span class="cl"> </span></span><span class="line"><span class="cl">; 中断服务程序 </span></span><span class="line"><span class="cl">MyISR PROC </span></span><span class="line"><span class="cl"> PUSH AX </span></span><span class="line"><span class="cl"> ; 处理键盘输入 </span></span><span class="line"><span class="cl"> POP AX </span></span><span class="line"><span class="cl"> IRET </span></span><span class="line"><span class="cl">MyISR ENDP </span></span></code></pre></td></tr></table> </div> </div><h2 id="bios-中断"><a href="#bios-%e4%b8%ad%e6%96%ad" class="header-anchor"></a>BIOS 中断 </h2><table> <thead> <tr> <th style="text-align:left">中断</th> <th style="text-align:left">功能号</th> <th style="text-align:left">用途</th> </tr> </thead> <tbody> <tr> <td style="text-align:left"><strong>INT 10h</strong></td> <td style="text-align:left">AH=00h</td> <td style="text-align:left">设置显示模式</td> </tr> <tr> <td style="text-align:left"><strong>INT 10h</strong></td> <td style="text-align:left">AH=0Eh</td> <td style="text-align:left">显示字符（TTY）</td> </tr> <tr> <td style="text-align:left"><strong>INT 13h</strong></td> <td style="text-align:left">AH=02h</td> <td style="text-align:left">读磁盘扇区</td> </tr> <tr> <td style="text-align:left"><strong>INT 16h</strong></td> <td style="text-align:left">AH=00h</td> <td style="text-align:left">读取键盘按键</td> </tr> </tbody> </table> <h2 id="总结"><a href="#%e6%80%bb%e7%bb%93" class="header-anchor"></a>总结 </h2><p>中断是硬件与软件的桥梁。理解中断机制，你就掌握了操作系统与硬件对话的语言。</p> <blockquote> <p>下一篇：《多模块程序设计与混合编程：C 语言调用汇编》</p> </blockquote>