From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 6060 invoked by alias); 25 Mar 2007 06:35:19 -0000 Received: (qmail 6050 invoked by uid 22791); 25 Mar 2007 06:35:18 -0000 X-Spam-Check-By: sourceware.org Received: from ug-out-1314.google.com (HELO ug-out-1314.google.com) (66.249.92.173) by sourceware.org (qpsmtpd/0.31) with ESMTP; Sun, 25 Mar 2007 07:35:16 +0100 Received: by ug-out-1314.google.com with SMTP id 75so1346023ugb for ; Sat, 24 Mar 2007 23:35:13 -0700 (PDT) Received: by 10.115.89.1 with SMTP id r1mr2015463wal.1174804511675; Sat, 24 Mar 2007 23:35:11 -0700 (PDT) Received: from Zhao ( [58.41.144.136]) by mx.google.com with ESMTP id m29sm6750759poh.2007.03.24.23.35.10; Sat, 24 Mar 2007 23:35:11 -0700 (PDT) Date: Sun, 25 Mar 2007 06:35:00 -0000 To: "gdb" Subject: Need help debuging i386 in real mode. Message-ID: <200703251435091123125@gmail.com> X-mailer: Foxmail 6, 5, 104, 21 [cn] Mime-Version: 1.0 Content-Type: text/plain; charset="gb2312" Content-Transfer-Encoding: 7bit From: "Develop.ReactOS" X-IsSubscribed: yes Mailing-List: contact gdb-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-owner@sourceware.org X-SW-Source: 2007-03/txt/msg00303.txt.bz2 Hello: I am trying to debug i386 in real mode. How to disassemble 16-bit code? gdb appears to always assume a 32-bit segment.Is there a way to coerce gdb into 16-bit disassembly mode? Is there some other tool or cmd I could use? I need 16-bit disassembly instruction,but gdb's output is wrong: (gdb) x /10i $eip+$cs*16 0xffff0: ljmp 0x3131,0xf000e05b 0xffff7: das 0xffff8: xor BYTE PTR [ecx],dh 0xffffa: das 0xffffb: xor BYTE PTR [esi],dh 0xffffd: add ah,bh 0xfffff: test DWORD PTR [eax],0x0 0x100005: add BYTE PTR [eax],al 0x100007: add BYTE PTR [eax],al 0x100009: add BYTE PTR [eax],al Best regards! Develop.ReactOS 2007-03-25