1 files changed, 58 insertions, 0 deletions
diff --git a/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/PeiCpuTimerLib.c b/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/PeiCpuTimerLib.c
new file mode 100644
index 000000000..91a721205
--- /dev/null
+++ b/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/PeiCpuTimerLib.c
@@ -0,0 +1,58 @@
+/** @file
+  CPUID Leaf 0x15 for Core Crystal Clock frequency instance as PEI Timer Library.
+
+  Copyright (c) 2019 Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <PiPei.h>
+#include <Library/TimerLib.h>
+#include <Library/BaseLib.h>
+#include <Library/HobLib.h>
+#include <Library/DebugLib.h>
+
+extern GUID mCpuCrystalFrequencyHobGuid;
+
+/**
+  CPUID Leaf 0x15 for Core Crystal Clock Frequency.
+
+  The TSC counting frequency is determined by using CPUID leaf 0x15. Frequency in MHz = Core XTAL frequency * EBX/EAX.
+  In newer flavors of the CPU, core xtal frequency is returned in ECX or 0 if not supported.
+  @return The number of TSC counts per second.
+
+**/
+UINT64
+CpuidCoreClockCalculateTscFrequency (
+  VOID
+  );
+
+/**
+  Internal function to retrieves the 64-bit frequency in Hz.
+
+  Internal function to retrieves the 64-bit frequency in Hz.
+
+  @return The frequency in Hz.
+
+**/
+UINT64
+InternalGetPerformanceCounterFrequency (
+  VOID
+  )
+{
+  UINT64              *CpuCrystalCounterFrequency;
+  EFI_HOB_GUID_TYPE   *GuidHob;
+
+  CpuCrystalCounterFrequency = NULL;
+  GuidHob = GetFirstGuidHob (&mCpuCrystalFrequencyHobGuid);
+  if (GuidHob == NULL) {
+    CpuCrystalCounterFrequency  = (UINT64*)BuildGuidHob(&mCpuCrystalFrequencyHobGuid, sizeof (*CpuCrystalCounterFrequency));
+    ASSERT (CpuCrystalCounterFrequency != NULL);
+    *CpuCrystalCounterFrequency = CpuidCoreClockCalculateTscFrequency ();
+  } else {
+    CpuCrystalCounterFrequency = (UINT64*)GET_GUID_HOB_DATA (GuidHob);
+  }
+
+  return  *CpuCrystalCounterFrequency;
+}
+