From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.33) id 1BxApR-0008SP-01 for qemu-devel@nongnu.org; Tue, 17 Aug 2004 16:45:09 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.33) id 1BxApO-0008SD-Sr for qemu-devel@nongnu.org; Tue, 17 Aug 2004 16:45:08 -0400 Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.33) id 1BxApO-0008SA-JA for qemu-devel@nongnu.org; Tue, 17 Aug 2004 16:45:06 -0400 Received: from [151.189.21.46] (helo=mail-in-01.arcor-online.net) by monty-python.gnu.org with esmtp (TLSv1:DES-CBC3-SHA:168) (Exim 4.34) id 1BxAkl-0003HU-28 for qemu-devel@nongnu.org; Tue, 17 Aug 2004 16:40:19 -0400 Received: from hatatitla.NotaMusica.com (dsl-082-082-144-198.arcor-ip.net [82.82.144.198]) by mail-in-01.arcor-online.net (Postfix) with ESMTP id CA788D5B9 for ; Tue, 17 Aug 2004 22:40:17 +0200 (CEST) Received: from hatatitla.NotaMusica.com (jmartin@localhost [127.0.0.1]) by hatatitla.NotaMusica.com (8.12.3/8.12.3/Debian-6.6) with ESMTP id i7HKeHjb002235 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Tue, 17 Aug 2004 22:40:17 +0200 Received: from localhost (jmartin@localhost) by hatatitla.NotaMusica.com (8.12.3/8.12.3/Debian-6.6) with ESMTP id i7HKeHR8002230 for ; Tue, 17 Aug 2004 22:40:17 +0200 Date: Tue, 17 Aug 2004 22:40:17 +0200 (CEST) From: Johannes Martin Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Subject: [Qemu-devel] Qemu floppy emulation problems - partially solved Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Hi, a little while ago we had some discussion about floppy emulation not working in qemu once an OS has been installed. Our assumption was that floppy access worked through int13 bios emulation but not really down at the hardware level. Today I noticed in Win98 that Windows would only offer to format a floppy at 180kB. I then booted Win98 with a floppy inserted at boot time and noticed two things: - rather than two 'removable disk drives' Win98 now only reports one 3 1/2" floppy drive (correctly) - I can actually access that floppy and other floppies I insert later (no disk change problem as with CDs) Observations on other OSes: - Win95 reports a VFAT error and pretty much dies - OS/2 can access the floppy that was inserted originally, as soon as I try to access any other floppy, qemu dies with a segmentation fault. Tested on Debian/GNU Linux with a two week old qemu/CVS. So I guess our initial assumption was at least partially incorrect, the problem is not (primarily) the fdc hardware emulation in general but the part OSes need to detect the kind of floppy drive installed. Apparently, if no virtual floppy is inserted, the detection fails. I haven't actually looked at the code yet - I imagine it to be quite easy to fix though. Any hints how to find out why/where qemu segfaults under OS/2? How can I get a core dump out of qemu? So far, my attempts to debug qemu using gdb have failed miserably. :( Thanks Johannes