Explanation from Michael Kinney: This PCD allows a platform to provide PlatformSmmBspElection() in a platform specific SmmCpuPlatformHookLib instance to decide which CPU gets elected to be the BSP in each SMI.
The SmmCpuPlatformHookLibNull [instance] always returns EFI_NOT_READY for that function, which makes the module behave the same as the PCD being set to FALSE. The default is TRUE, so the platform lib is always called, so a platform developer can implement the hook function and does not have to also change a PCD setting for the hook function to be active. A platform that wants to eliminate the call to the hook function [altogether] can set the PCD to FALSE. So for OVMF, I think it makes sense to set this PCD to FALSE in the DSC file. Suggested-by: Michael Kinney <[email protected]> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Laszlo Ersek <[email protected]> --- Notes: v2: - This patch replaces the v1 patch "OvmfPkg: import PCDs from Quark_EDKII_v1.1.0/IA32FamilyCpuBasePkg". That patch overrode the default for the PCD just the same, but it used different justification (= "Quark's IA32FamilyCpuBasePkg.dsc disables it too"). Plus, the goal of that patch was primarily to import PCDs to OvmfPkg.dec, under "gQuarkPortCpuTokenSpaceGuid", which is now unnecessary due to Mike's work. OvmfPkg/OvmfPkgIa32.dsc | 1 + OvmfPkg/OvmfPkgIa32X64.dsc | 1 + OvmfPkg/OvmfPkgX64.dsc | 1 + 3 files changed, 3 insertions(+) diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc index 41650e8..d8df8cc 100644 --- a/OvmfPkg/OvmfPkgIa32.dsc +++ b/OvmfPkg/OvmfPkgIa32.dsc @@ -342,6 +342,7 @@ [PcdsFeatureFlag] !endif !if $(SMM_REQUIRE) == TRUE gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE + gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE !endif [PcdsFixedAtBuild] diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc index 676c99c..b26eb8b 100644 --- a/OvmfPkg/OvmfPkgIa32X64.dsc +++ b/OvmfPkg/OvmfPkgIa32X64.dsc @@ -347,6 +347,7 @@ [PcdsFeatureFlag] !endif !if $(SMM_REQUIRE) == TRUE gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE + gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE !endif [PcdsFixedAtBuild] diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc index d61eae9..a7c803a 100644 --- a/OvmfPkg/OvmfPkgX64.dsc +++ b/OvmfPkg/OvmfPkgX64.dsc @@ -347,6 +347,7 @@ [PcdsFeatureFlag] !endif !if $(SMM_REQUIRE) == TRUE gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire|TRUE + gUefiCpuPkgTokenSpaceGuid.PcdCpuSmmEnableBspElection|FALSE !endif [PcdsFixedAtBuild] -- 1.8.3.1 _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
