From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=209.132.183.28; helo=mx1.redhat.com; envelope-from=lersek@redhat.com; receiver=edk2-devel@lists.01.org Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 79FBC20352A83 for ; Fri, 1 Dec 2017 02:59:34 -0800 (PST) Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4DD1B19CF89; Fri, 1 Dec 2017 11:04:00 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-120-33.rdu2.redhat.com [10.10.120.33]) by smtp.corp.redhat.com (Postfix) with ESMTP id D182E60649; Fri, 1 Dec 2017 11:03:58 +0000 (UTC) To: Ard Biesheuvel Cc: edk2-devel-01 , Anthony Perard , Jordan Justen , Julien Grall References: <20171130163029.19743-1-lersek@redhat.com> <20171130163029.19743-5-lersek@redhat.com> From: Laszlo Ersek Message-ID: <60ab02c6-4a27-0a28-7e01-550415b26f1b@redhat.com> Date: Fri, 1 Dec 2017 12:03:57 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 01 Dec 2017 11:04:00 +0000 (UTC) Subject: Re: [PATCH v2 4/8] OvmfPkg: introduce FlashNvStorageAddressLib X-BeenThere: edk2-devel@lists.01.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: EDK II Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 01 Dec 2017 10:59:34 -0000 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 12/01/17 09:55, Ard Biesheuvel wrote: > On 30 November 2017 at 16:30, Laszlo Ersek wrote: >> An OVMF binary built with >> >> -D SMM_REQUIRE >> >> or with >> >> -D MEM_VARSTORE_EMU_ENABLE=FALSE >> >> requires flash to be present at the expected (build-time determined) >> location; falling back to the emulated varstore is not possible. >> >> In such builds, we can replace the settings of the >> - varstore, >> - FTW working block, >> - and FTW spare area >> address PCDs in QemuFlashFvbServicesRuntimeDxe with identical settings in >> a new plug-in (NULL class) library, to be linked into variable-related >> PEIMs. >> >> This will enable such builds to access variables during the PEI phase, >> without dynamic flash detection and without ordering constraints against >> other PEIMs. >> > > Why can't we set these at build time in this case? Hmm, let me think... Oh yes, I think I remember. The PCDs that are used as *source* here (i.e., passed as arguments to PcdGet32()) *are* set at build time. However, they take some calculation at build time too, and they are set in the "OvmfPkg/OvmfPkg.fdf.inc" file, with explicit SET statments. This is because you can build OVMF for a 1MB, 2MB, or 4MB unified flash image size, and the "source PCDs" in question depend on them. Furthermore, these "source PCDs" are fixed-at-build. I think I couldn't find a way to set the defaults for the "target", dynamic, PCDs, from the build-time-calculated "source PCDs". The usual dynamic-default setting in the DSC does not work (because the default value is not a numeric constant), and, as far as I remember, when I tried the SET command on the dynamic ("target") PCDs as well, it simply didn't work. The SET statements *could* work if the target PCDs could be made (conditionally) fixed-at-build as well, but then we run into the same build problem of ReserveEmuVariableNvStore() not compiling. In short: - the "target" PCDs have to remain dynamic, or else ReserveEmuVariableNvStore() won't compile, - as long as the "target" PCDs are dynamic, I cannot set their defaults at build time *from* the "source" fixed-at-build PCDs, which are calculated at each build separately, with the SET statement. Thanks Laszlo > >> Cc: Anthony Perard >> Cc: Ard Biesheuvel >> Cc: Jordan Justen >> Cc: Julien Grall >> Contributed-under: TianoCore Contribution Agreement 1.0 >> Signed-off-by: Laszlo Ersek >> --- >> OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.inf | 48 ++++++++++++++++++ >> OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.c | 53 ++++++++++++++++++++ >> 2 files changed, 101 insertions(+) >> >> diff --git a/OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.inf b/OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.inf >> new file mode 100644 >> index 000000000000..f79194f80de9 >> --- /dev/null >> +++ b/OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.inf >> @@ -0,0 +1,48 @@ >> +## @file >> +# >> +# A hook-in library for variable-related PEIMs, in order to set >> +# - gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64, >> +# - gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase, >> +# - gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase, >> +# from their gUefiOvmfPkgTokenSpaceGuid counterparts, just before those PEIMs >> +# consume them. >> +# >> +# Copyright (C) 2017, Red Hat, Inc. >> +# >> +# This program and the accompanying materials are licensed and made available >> +# under the terms and conditions of the BSD License which accompanies this >> +# distribution. The full text of the license may be found at >> +# http://opensource.org/licenses/bsd-license.php >> +# >> +# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT >> +# WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. >> +# >> +## >> + >> +[Defines] >> + INF_VERSION = 1.25 >> + BASE_NAME = FlashNvStorageAddressLib >> + FILE_GUID = 5FF5A9F9-D01E-49EC-9A17-1682FC85122F >> + MODULE_TYPE = BASE >> + VERSION_STRING = 1.0 >> + LIBRARY_CLASS = FlashNvStorageAddressLib|PEIM >> + CONSTRUCTOR = SetFlashNvStorageAddresses >> + >> +[Sources] >> + FlashNvStorageAddressLib.c >> + >> +[Packages] >> + MdePkg/MdePkg.dec >> + MdeModulePkg/MdeModulePkg.dec >> + OvmfPkg/OvmfPkg.dec >> + >> +[LibraryClasses] >> + PcdLib >> + >> +[Pcd] >> + gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase >> + gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase >> + gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64 >> + gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageFtwSpareBase >> + gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageFtwWorkingBase >> + gUefiOvmfPkgTokenSpaceGuid.PcdOvmfFlashNvStorageVariableBase >> diff --git a/OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.c b/OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.c >> new file mode 100644 >> index 000000000000..dc1280cc23f1 >> --- /dev/null >> +++ b/OvmfPkg/Library/FlashNvStorageAddressLib/FlashNvStorageAddressLib.c >> @@ -0,0 +1,53 @@ >> +/** @file >> + >> + A hook-in library for variable-related PEIMs, in order to set >> + - gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageVariableBase64, >> + - gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwWorkingBase, >> + - gEfiMdeModulePkgTokenSpaceGuid.PcdFlashNvStorageFtwSpareBase, >> + from their gUefiOvmfPkgTokenSpaceGuid counterparts, just before those PEIMs >> + consume them. >> + >> + Copyright (C) 2017, Red Hat, Inc. >> + >> + This program and the accompanying materials are licensed and made available >> + under the terms and conditions of the BSD License which accompanies this >> + distribution. The full text of the license may be found at >> + http://opensource.org/licenses/bsd-license.php >> + >> + THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT >> + WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. >> + >> +**/ >> + >> +#include >> + >> +RETURN_STATUS >> +EFIAPI >> +SetFlashNvStorageAddresses ( >> + VOID >> + ) >> +{ >> + RETURN_STATUS PcdStatus; >> + >> + PcdStatus = PcdSet64S ( >> + PcdFlashNvStorageVariableBase64, >> + PcdGet32 (PcdOvmfFlashNvStorageVariableBase) >> + ); >> + if (RETURN_ERROR (PcdStatus)) { >> + return PcdStatus; >> + } >> + >> + PcdStatus = PcdSet32S ( >> + PcdFlashNvStorageFtwWorkingBase, >> + PcdGet32 (PcdOvmfFlashNvStorageFtwWorkingBase) >> + ); >> + if (RETURN_ERROR (PcdStatus)) { >> + return PcdStatus; >> + } >> + >> + PcdStatus = PcdSet32S ( >> + PcdFlashNvStorageFtwSpareBase, >> + PcdGet32 (PcdOvmfFlashNvStorageFtwSpareBase) >> + ); >> + return PcdStatus; >> +} >> -- >> 2.14.1.3.gb7cf6e02401b >> >>