From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: Re: console: introduce console=none option Date: Thu, 26 Jan 2012 16:08:00 +0000 Message-ID: <20120126160800.GD80228@ocelot.phlegethon.org> References: <4F2144EE.9040808@citrix.com> <4F21743C020000780006F3AA@nat28.tlf.novell.com> <4F216A12.80602@citrix.com> <4F2186B4020000780006F429@nat28.tlf.novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <4F2186B4020000780006F429@nat28.tlf.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich Cc: Andrew Cooper , "xen-devel@lists.xensource.com" List-Id: xen-devel@lists.xenproject.org At 16:00 +0000 on 26 Jan (1327593636), Jan Beulich wrote: > >>> On 26.01.12 at 15:58, Andrew Cooper wrote: > > On 26/01/12 14:41, Jan Beulich wrote: > >>>>> On 26.01.12 at 13:19, Andrew Cooper wrote: > >>> XenServer by default boots without a serial console (buggy hardware > >>> reasons) and dom0 displays a splash screen. Unfortunately, having Xen > >>> writing to the vga text area looks ugly whilst dom0 is trying to set up > >>> non-text mode and display the splash screen. > >>> > >>> We have been using "console=" to prevent this behavior for a while, but > >>> presented herewith is a patch to fix the problem correctly. > >> While I don't mind the patch, I'm completely confused by the description: > >> Where is it that Xen writes to VGA text area after control was passed to > >> Dom0? > >> > >> Jan > > > > I have not debugged it that much as I was looking for a clean solution > > to our current hack of "console=" (and I have some rather more serious > > deadlock bugs to debug), but it all Xen printk's are going into the VGA > > text area, even after dom0 has started. It is possible that Xen is > > still writing into the text area after dom0 has switched VGA mode, but I > > have no proof of this one way or the other. > > Just take a look at vga_endboot() - the output routine gets pointed to > vga_noop_puts() unless vgacon_keep. Beyond that point nothing > can possibly get printed to the VGA text screen, or if it does, then I'd > suspect there's some other change in XenServer that makes it so. IIRC in some XenServer versions the bootloader also puts up a splashscreen; that may be causing some confusion. Tim.