From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mx.groups.io with SMTP id smtpd.web10.11062.1649262426956755774 for ; Wed, 06 Apr 2022 09:27:07 -0700 Authentication-Results: mx.groups.io; dkim=fail reason="body hash did not verify" header.i=@linux.microsoft.com header.s=default header.b=AcN9/q3t; spf=pass (domain: linux.microsoft.com, ip: 13.77.154.182, mailfrom: mikuback@linux.microsoft.com) Received: from localhost.localdomain (unknown [47.201.46.36]) by linux.microsoft.com (Postfix) with ESMTPSA id 99C0820DFD98; Wed, 6 Apr 2022 09:27:05 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 99C0820DFD98 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1649262426; bh=dNwxi6uOfzJtFDArnKbUvpcgX9ZpPJOKzezzhM/rep8=; h=From:To:Cc:Subject:Date:From; b=AcN9/q3t85mbpwgYGDyIHZ8IdeZk42MCbu01wF3Jg4Scqk/rCidYUN9+iFf9rzviq /6Vwj/sBD3j9paJuZj3jzOXLjEBFy4gYMjTZW70L+Yj6C4Cp0umgIkZTnSDHCSk3kk bf12/GNNkeGXUdsGDM3+6qvOes2lvWZXfUWpSITI= From: "Michael Kubacki" To: devel@edk2.groups.io Cc: Jian J Wang , Hao A Wu , Liming Gao Subject: [PATCH v1 0/3] Add Variable Flash Info HOB Date: Wed, 6 Apr 2022 12:26:45 -0400 Message-Id: <20220406162648.234-1-mikuback@linux.microsoft.com> X-Mailer: git-send-email 2.28.0.windows.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable From: Michael Kubacki REF:https://bugzilla.tianocore.org/show_bug.cgi?id=3D3479 The UEFI variable drivers such as VariableRuntimeDxe, VariableSmm, VariableStandaloneMm, etc. (and their dependent protocol/library stack), typically acquire UEFI variable store flash information with PCDs declared in MdeModulePkg. For example: [Pcd] gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64 gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableSize These PCDs work as-is in the StandaloneMm driver if they are not dynamic such as Dynamic or DynamicEx because PCD services are not readily available in the Standalone MM environment. Platforms that use Standalone MM today, must define these PCDs as FixedAtBuild in their platform build. However, the PCDs do allow platforms to treat the PCDs as Dynamic/DynamicEx and being able to support that is currently a gap for Standalone MM. This patch series introduces a HOB that can be produced by the platform to provide the same information. The HOB list is available to Standalone MM. The PCD declarations are left as-is in MdeModulePkg for backward compatibility. This means unless a platform wants to use the HOB, their code will continue to work with no change (they do not need to produce the HOB). Only if the HOB is found, is its value used instead of the PCDs. Cc: Jian J Wang Cc: Hao A Wu Cc: Liming Gao Signed-off-by: Michael Kubacki