From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=40272 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1P2gu5-0008BK-Kj for qemu-devel@nongnu.org; Mon, 04 Oct 2010 05:00:14 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1P2gu4-0000lB-5G for qemu-devel@nongnu.org; Mon, 04 Oct 2010 05:00:13 -0400 Received: from goliath.siemens.de ([192.35.17.28]:16623) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1P2gu3-0000kf-Sb for qemu-devel@nongnu.org; Mon, 04 Oct 2010 05:00:12 -0400 Message-ID: <4CA99797.7000402@siemens.com> Date: Mon, 04 Oct 2010 11:00:07 +0200 From: Jan Kiszka MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: [Qemu-devel] Re: 64-bit Qemu and remote GDB to Kernel Error List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Matt Davis Cc: qemu-devel Am 04.10.2010 04:47, Matt Davis wrote: > Hello, > I am trying to debug a 32-bit linux kernel with gdb and qemu. My qemu > runs the 64-bit kernel as: > user@host> qemu -kernel vmlinuz -S -s (not using kvm). If I try with > kvm the breakpoint does not even seem to get tripped. Which qemu version is affected by this issue? > > And then I fire up gdb on my 64-bit machine (the same one running > qemu). And I set my "target remote :1234" and set a breakpoint. > Anyways, I seem to catch my breakpoint, but when it should be tripping > I get the following error : > Remote 'g' packet reply is too long: > > I have done similar stuff fine on a 32bit machine running both 32-bit > qemu and a 32-bit kernel. I have also googled, and this seems to not > be uncommon (circa 2008). But I have not seen anything recently > regarding this. Should it be working now? If not is there a better > solution? I tried, on my 64bit machine, to run a 32-bit kernel in > qemu, but my breakpoints were still not tripping in gdb. Yes, the > kernel did have debugging flags built in. I also forced the gdb > architecture to use "set arch i386:x86-64" not much difference if I > recall. > > The following thread had similar issues when trying to set a break in > 64 bit land, but not mention of the error I reported above. These > possibly cold be related: > http://lists.gnu.org/archive/html/qemu-devel/2008-05/msg00287.html Please also see this thread http://thread.gmane.org/gmane.comp.emulators.qemu/80327. Did you follow the procedure I suggested? I cannot derive this from your description. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux