audk/OvmfPkg/Library/ResetSystemLib/BaseResetSystemLib.inf

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## @file
# Base library instance for ResetSystem library class for OVMF
#
# Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
##
[Defines]
INF_VERSION = 0x00010005
BASE_NAME = BaseResetSystemLib
FILE_GUID = 66564872-21d4-4d2a-a68b-1e844f980820
MODULE_TYPE = BASE
VERSION_STRING = 1.0
OvmfPkg/ResetSystemLib: introduce the DxeResetSystemLib instance The BaseResetSystemLib instance is not suitable for OS runtime, because its ResetShutdown() implementation calls PciRead16 (OVMF_HOSTBRIDGE_DID). On q35, this boils down to a memory-mapped config space access -- but we never ask the OS to map MMCONFIG for runtime. There are at least three alternatives to approach this: (1) Investigate "MdePkg/Library/DxeRuntimePciExpressLib", which offers some kind of runtime mapping for MMCONFIG. (2) Consume PciCf8Lib directly, rather than PciLib, in ResetSystemLib. Then we'll read OVMF_HOSTBRIDGE_DID from the config space with IO port accesses on q35 too, not just on i440fx. IO ports don't depend on page tables. (3) In the lib constructor, cache "mAcpiPmBaseAddress" based on "PcdOvmfHostBridgePciDevId" (which is set by PlatformPei). Then the host bridge type will be known at runtime without PCI config space accesses. This patch follows approach (3), in order to mirror AcpiTimerLib. Notes: * This patch is best viewed with "git show --find-copies-harder -C43". * PCDs are not usable in the DXE_CORE, as the PCD PPI is gone, and the PCD protocol is not available yet. (The DXE_CORE does consume ResetSystemLib in practice, when OVMF is built with -D SOURCE_DEBUG_ENABLE.) Cc: Anthony Perard <anthony.perard@citrix.com> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com> Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Julien Grall <julien@xen.org> Cc: Philippe Mathieu-Daudé <philmd@redhat.com> Cc: Rebecca Cran <rebecca@bsdio.com> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2675 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Message-Id: <20200417153751.7110-7-lersek@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@arm.com> Reviewed-by: Rebecca Cran <rebecca@bsdio.com> [lersek@redhat.com: move third Note (with repro info) to BZ comment]
2020-04-17 17:37:51 +02:00
LIBRARY_CLASS = ResetSystemLib|SEC PEI_CORE PEIM DXE_CORE
#
# The following information is for reference only and not required by the build
# tools.
#
# VALID_ARCHITECTURES = IA32 X64
#
[Sources]
BaseResetShutdown.c
ResetSystemLib.c
[Packages]
MdeModulePkg/MdeModulePkg.dec
MdePkg/MdePkg.dec
OvmfPkg/OvmfPkg.dec
[LibraryClasses]
BaseLib
DebugLib
IoLib
PciLib
TimerLib