From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58956) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W5LJN-00070q-C0 for qemu-devel@nongnu.org; Mon, 20 Jan 2014 15:19:14 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1W5LJE-0002T1-LO for qemu-devel@nongnu.org; Mon, 20 Jan 2014 15:19:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41527) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1W5LJE-0002Sp-CQ for qemu-devel@nongnu.org; Mon, 20 Jan 2014 15:19:00 -0500 Date: Mon, 20 Jan 2014 22:23:42 +0200 From: "Michael S. Tsirkin" Message-ID: <20140120202342.GA14528@redhat.com> References: <20140110171311.02e71f62@nial.usersys.redhat.com> <20140117211015.GB18752@ERROL.INI.CMU.EDU> <20140120115850.GA29985@redhat.com> <52DD0F3E.5010903@redhat.com> <20140120120842.GA31500@redhat.com> <52DD1382.3080607@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52DD1382.3080607@redhat.com> Subject: Re: [Qemu-devel] RFC: ACPI, HPET._CRS, MacOSX vs. WinXP List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: imammedo@redhat.com, "Gabriel L. Somlo" , lersek@redhat.com, qemu-devel@nongnu.org, agraf@suse.de On Mon, Jan 20, 2014 at 01:16:02PM +0100, Paolo Bonzini wrote: > Il 20/01/2014 13:08, Michael S. Tsirkin ha scritto: > >>> > > > >>> > > I think the hack looking for the SMC device is safer than _OSI: OSPMs > >>> > > are known to do crazy things when they see _OSI, such as assuming they > >>> > > need to try and emulate the OS probed. > >> > > >> > Source? > >> > > >> > Paolo > > For example, this one > > http://article.gmane.org/gmane.comp.bios.coreboot.seabios/7235 > > No, not source code. > > Source for "OSPMs do crazy things when they see _OSI". > > Paolo Ah, that one. For example, this msdn article at microsoft.com: http://msdn.microsoft.com/en-us/library/windows/hardware/gg463275.aspx "How to Identify the Windows Version in ACPI by Using _OSI" at the end it states: the operating system makes features available based on the string argument to the _OSI method. The ACPI spec states this in a more verbose form: 5.7.2 _OSI (Operating System Interfaces) OSPM can choose to expose new functionality based on the _OSI argument string. That is, OSPM can use the strings passed into _OSI to ensure compatibility between older platforms and newer operating systems by maintaining known compatible behavior for a platform. The concern therefore is that if bios only queries OSI for Darwin and not other OSes, some OSPM will assume it's a macbook hardware and do something stupid. -- MST