From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38490) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TZqMu-0006vp-3o for qemu-devel@nongnu.org; Sat, 17 Nov 2012 16:56:07 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TZqMr-0006de-1a for qemu-devel@nongnu.org; Sat, 17 Nov 2012 16:56:04 -0500 Received: from mout.web.de ([212.227.17.11]:51179) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TZqMq-0006dK-NF for qemu-devel@nongnu.org; Sat, 17 Nov 2012 16:56:00 -0500 Date: Sat, 17 Nov 2012 22:55:58 +0100 From: Goswin von Brederlow Message-ID: <20121117215557.GA5632@frosties> References: <20121117175025.GA12627@frosties> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] Can't switch to 64bit mode at boot, how to debug? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Filippov Cc: qemu-devel@nongnu.org On Sat, Nov 17, 2012 at 11:18:03PM +0300, Max Filippov wrote: > On Sat, Nov 17, 2012 at 11:58 PM, Max Filippov wrote: > > On Sat, Nov 17, 2012 at 9:50 PM, Goswin von Brederlow wrote: > >> /* Enable PAE */ > >> movl %cr4, %eax > >> btsl $5, %eax > >> movl %eax, %cr4 > > > > Interestingly with the current HEAD the code disappears after this instruction: > > ...only from gdb output. xp in qemu monitor still works, looks like > the issue here > is with code access for gdb. > > Otherwise it works for me both with the current HEAD, and with v1.1.0. > I built your kernel like this: > > gcc -I. -m32 test.S -nodefaultlibs -nostartfiles -Wl,-N -Wl,-Ttext > -Wl,100000 -Wl,--build-id=none -o test > > -- > Thanks. > -- Max > Args, the problem was that I used "qemu", which currently links to qemu-system-i386 instead of "qemu-system-x86_64". A some point in the last year the alternative setting must have reverted from x86_64 to the default of i386. MfG Goswin