From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16086 invoked by alias); 31 Oct 2011 17:26:03 -0000 Received: (qmail 16059 invoked by uid 22791); 31 Oct 2011 17:26:01 -0000 X-SWARE-Spam-Status: No, hits=0.4 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW X-Spam-Check-By: sourceware.org Received: from mail-qw0-f41.google.com (HELO mail-qw0-f41.google.com) (209.85.216.41) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 31 Oct 2011 17:25:47 +0000 Received: by qadc11 with SMTP id c11so6122373qad.0 for ; Mon, 31 Oct 2011 10:25:46 -0700 (PDT) MIME-Version: 1.0 Received: by 10.68.38.41 with SMTP id d9mr24519393pbk.103.1320081946344; Mon, 31 Oct 2011 10:25:46 -0700 (PDT) Received: by 10.68.43.137 with HTTP; Mon, 31 Oct 2011 10:25:46 -0700 (PDT) Date: Mon, 31 Oct 2011 17:43:00 -0000 Message-ID: Subject: How "can't compute CFA for this frame" and "no enough registers or memory available to further unwind" happen? From: zhihua che To: gdb Content-Type: text/plain; charset=ISO-8859-1 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: 2011-10/txt/msg00241.txt.bz2 Hi, everyone I'm not sure this is right place for the help. I'm writing a toy os and coding with mixed assembly and C language, debugging with GDB. But I'm trapped with an annoying problem. This is my situation: During the os booting time, after the os control transfers from real mode assembly codes to real mode C codes, I wish I can exam the stack frames and local variable as I do in regular application program, but I always get "can't compute CFA for this frame" or "No enough registers or memory available to further unwind" if I issue "print xxx" or "backtrace" command respectivelly. The codes seem work, but I can only exam registers or memory using "info reg" or "x" command, it's way unfriendly and time-consuming. I have searched a lot but don't figure out how these happen. I need your help. Thanks. Harvey