diff options
| author | Jeff Fan <jeff.fan@intel.com> | 2015-12-08 05:19:34 +0000 |
|---|---|---|
| committer | vanjeff <vanjeff@Edk2> | 2015-12-08 05:19:34 +0000 |
| commit | 46309b1101b626c8d3528d85d48383ea156fedf0 (patch) | |
| tree | e511e1fc95bfa5c4521a24da1e529ec1ea0f6093 /UefiCpuPkg/Library/MtrrLib/MtrrLib.c | |
| parent | 5c1edc553492d031d66ac2bfcf134d72e513c415 (diff) | |
| download | edk2-platforms-46309b1101b626c8d3528d85d48383ea156fedf0.tar.xz | |
UefiCpuPkg/MtrrLib: Add PCD PcdCpuNumberOfReservedVariableMtrrs
Current MtrrLib reserves 2 variable MTRRs for some legacy OS boot (CSM boots)
may require some MTRRs to be reserved for OS use. But UEFI OS boot will not use
MTRRs.
Per Scott's suggestion in
link: http://article.gmane.org/gmane.comp.bios.edk2.devel/4099
Add one PCD PcdCpuNumberOfReservedVariableMtrrs to specify the number of
variable MTRRs reserved for OS use. Setting its default value to 2 is for
back-compatibility.
Cc: Scott Duplichan <scott@notabs.org>
Cc: Feng Tian <feng.tian@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Suggested-by: Scott Duplichan <scott@notabs.org>
Reviewed-by: Feng Tian <feng.tian@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19151 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'UefiCpuPkg/Library/MtrrLib/MtrrLib.c')
| -rw-r--r-- | UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c index a65560542c..82223379e7 100644 --- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c +++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c @@ -140,13 +140,15 @@ GetFirmwareVariableMtrrCount ( )
{
UINT32 VariableMtrrCount;
+ UINT32 ReservedMtrrNumber;
VariableMtrrCount = GetVariableMtrrCount ();
- if (VariableMtrrCount < RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER) {
+ ReservedMtrrNumber = PcdGet32 (PcdCpuNumberOfReservedVariableMtrrs);
+ if (VariableMtrrCount < ReservedMtrrNumber) {
return 0;
}
- return VariableMtrrCount - RESERVED_FIRMWARE_VARIABLE_MTRR_NUMBER;
+ return VariableMtrrCount - ReservedMtrrNumber;
}
/**
|