From mboxrd@z Thu Jan 1 00:00:00 1970 Received: by 10.25.159.19 with SMTP id i19csp2703340lfe; Wed, 10 Feb 2016 12:42:40 -0800 (PST) X-Received: by 10.140.86.243 with SMTP id p106mr51733642qgd.1.1455136959624; Wed, 10 Feb 2016 12:42:39 -0800 (PST) Return-Path: Received: from lists.gnu.org (lists.gnu.org. [2001:4830:134:3::11]) by mx.google.com with ESMTPS id z2si5457661qkg.60.2016.02.10.12.42.39 for (version=TLS1 cipher=AES128-SHA bits=128/128); Wed, 10 Feb 2016 12:42:39 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; spf=pass (google.com: domain of qemu-devel-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+alex.bennee=linaro.org@nongnu.org Received: from localhost ([::1]:42941 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aTbax-0008GR-50 for alex.bennee@linaro.org; Wed, 10 Feb 2016 15:42:39 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58306) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aTbaB-0007AS-0f for qemu-devel@nongnu.org; Wed, 10 Feb 2016 15:41:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aTba9-0008OB-Vj for qemu-devel@nongnu.org; Wed, 10 Feb 2016 15:41:50 -0500 Received: from relay-05.andrew.cmu.edu ([128.2.157.12]:39562 helo=relay.andrew.cmu.edu) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aTba6-0008LJ-5O; Wed, 10 Feb 2016 15:41:46 -0500 Received: from HEDWIG.ini.cmu.edu (HEDWIG.INI.CMU.EDU [128.2.16.51]) by relay.andrew.cmu.edu (8.14.7/8.14.7) with ESMTP id u1AKfeYF004670; Wed, 10 Feb 2016 15:41:41 -0500 From: "Gabriel L. Somlo" To: qemu-devel@nongnu.org Date: Wed, 10 Feb 2016 15:41:40 -0500 Message-Id: <1455136900-22334-6-git-send-email-somlo@cmu.edu> X-Mailer: git-send-email 2.4.3 In-Reply-To: <1455136900-22334-1-git-send-email-somlo@cmu.edu> References: <1455136900-22334-1-git-send-email-somlo@cmu.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Scanned-By: MIMEDefang 2.74 on 128.2.157.12 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay.andrew.cmu.edu id u1AKfeYF004670 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x X-Received-From: 128.2.157.12 Cc: peter.maydell@linaro.org, ehabkost@redhat.com, mst@redhat.com, matt@codeblueprint.co.uk, stefanha@gmail.com, ard.biesheuvel@linaro.org, leif.lindholm@linaro.org, luto@amacapital.net, qemu-arm@nongnu.org, kraxel@redhat.com, pbonzini@redhat.com, imammedo@redhat.com, lersek@redhat.com, rth@twiddle.net Subject: [Qemu-devel] [PATCH v7 5/5] fw_cfg: document ACPI device node information X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+alex.bennee=linaro.org@nongnu.org Sender: qemu-devel-bounces+alex.bennee=linaro.org@nongnu.org X-TUID: d9Fw5yo/h0N2 Signed-off-by: Gabriel Somlo Reviewed-by: Laszlo Ersek Reviewed-by: Marc Mar=C3=AD --- docs/specs/fw_cfg.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index 2099ad9..5414140 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -84,6 +84,15 @@ Selector Register address: Base + 8 (2 bytes) Data Register address: Base + 0 (8 bytes) DMA Address address: Base + 16 (8 bytes) =20 +=3D=3D ACPI Interface =3D=3D + +The fw_cfg device is defined with ACPI ID "QEMU0002". Since we expect +ACPI tables to be passed into the guest through the fw_cfg device itself= , +the guest-side firmware can not use ACPI to find fw_cfg. However, once t= he +firmware is finished setting up ACPI tables and hands control over to th= e +guest kernel, the latter can use the fw_cfg ACPI node for a more accurat= e +inventory of in-use IOport or MMIO regions. + =3D=3D Firmware Configuration Items =3D=3D =20 =3D=3D=3D Signature (Key 0x0000, FW_CFG_SIGNATURE) =3D=3D=3D --=20 2.4.3