From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60555) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1daSoq-0001Ru-8f for qemu-devel@nongnu.org; Wed, 26 Jul 2017 16:22:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1daSon-00032m-KU for qemu-devel@nongnu.org; Wed, 26 Jul 2017 16:22:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56760) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1daSon-000322-Ee for qemu-devel@nongnu.org; Wed, 26 Jul 2017 16:22:05 -0400 Date: Wed, 26 Jul 2017 16:22:00 -0400 (EDT) From: Paolo Bonzini Message-ID: <771944749.19250153.1501100520383.JavaMail.zimbra@redhat.com> In-Reply-To: <20170726230055-mutt-send-email-mst@kernel.org> References: <20170726094235.14267-1-pbonzini@redhat.com> <20170726094235.14267-2-pbonzini@redhat.com> <20170726230055-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [seabios PATCH 1/2] seabios: build RSDT from XSDT List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: seabios@seabios.org, Kevin O'Connor , qemu-devel@nongnu.org, lersek@redhat.com, lists@philjordan.eu, imammedo@redhat.com, phil@philjordan.eu, programmingkidx@gmail.com, kraxel@redhat.com ----- Original Message ----- > From: "Michael S. Tsirkin" > To: "Paolo Bonzini" > Cc: seabios@seabios.org, "Kevin O'Connor" , qemu-devel@nongnu.org, lersek@redhat.com, > lists@philjordan.eu, imammedo@redhat.com, phil@philjordan.eu, programmingkidx@gmail.com, kraxel@redhat.com > Sent: Wednesday, July 26, 2017 10:05:03 PM > Subject: Re: [seabios PATCH 1/2] seabios: build RSDT from XSDT > > On Wed, Jul 26, 2017 at 11:42:34AM +0200, Paolo Bonzini wrote: > > Old operating systems would like to have a rev1 (ACPI 1.0) FADT, but > > new operating systems would like to have rev3 (ACPI 2.0). > > > > Since old operating systems do not know about XSDTs, the > > solution is to point the RSDT to a rev1 FADT and the XSDT to a > > rev3 FADT. > > > > But, edk2 is not able to handle QEMU providing two FADTs and barfs when > > it sees the second; edk2 subscribes to the view that the platform code > > (meaning not only OVMF, but transitively QEMU's ACPI table builder) > > should not handle such hacks; it's common edk2 code that should handle > > FADT rev1 vs. rev3 and RSDT vs. XSDT. > > What exactly does it do wrt RSDT? It ignores the one produced by QEMU and builds it from scratch. Same for RSDP and XSDT. Paolo