From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53599) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cHnv1-0002fL-RG for qemu-devel@nongnu.org; Fri, 16 Dec 2016 03:31:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cHnuy-0007LW-O7 for qemu-devel@nongnu.org; Fri, 16 Dec 2016 03:31:07 -0500 Received: from indium.canonical.com ([91.189.90.7]:44822) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cHnuy-0007Jd-JZ for qemu-devel@nongnu.org; Fri, 16 Dec 2016 03:31:04 -0500 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.76 #1 (Debian)) id 1cHnux-0006By-79 for ; Fri, 16 Dec 2016 08:31:03 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 333242E8043 for ; Fri, 16 Dec 2016 08:31:03 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Fri, 16 Dec 2016 08:19:16 -0000 From: Thomas Huth <922076@bugs.launchpad.net> Reply-To: Bug 922076 <922076@bugs.launchpad.net> Sender: bounces@canonical.com References: <20120126133438.17636.69999.malonedeb@soybean.canonical.com> Message-Id: <20161216081917.20904.80719.launchpad@soybean.canonical.com> Errors-To: bounces@canonical.com Subject: [Qemu-devel] [Bug 922076] Re: doesn't clear screen on boot List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org ** Changed in: qemu Status: Incomplete =3D> Triaged -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/922076 Title: doesn't clear screen on boot Status in QEMU: Triaged Bug description: When I start Linux in Qemu via "qemu -kernel /vmlinuz ...", Qemu window appears and it shows message "Starting Seabios (version 0.5.1-2010...)", and then Linux writes messages like "Loading, please wait..." on top of previous message! For example, I can see "Loading, please wait...on 0.5.1-2010...)" So, Qemu doesn't clean screan before booting OS. Moreover, when I start Linux via "qemu /disk-image", Qemu shows "Starting Seabios (version 0.5.1-2010...)", then switches to graphical mode, shows GRUB, then switches back to text mode and shows "Starting Seabios" again! And again Linux prints messages on top of Seabios messages, and we see a mix of symbols on screen. Also, I found another bug! I am learning now to write kernels. And I see that operator "*(char *)0xb8000 =3D 0" in C code of kernel doesn't clean first charaster of screen in Qemu in "-curses" mode! If I want to real clean this charaster, I must type "*(char *)0xb8000 =3D ' '". I attach a kernel (x86, multiboot) with this bug. Just type "make" (you need gcc) and "qemu -curses -kernel kernel". You will see that screen is not cleared, but kernel tries to clean it. If you change 0 to ' ', all will work! To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/922076/+subscriptions