1 files changed, 41 insertions, 0 deletions
diff --git a/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c b/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c
new file mode 100644
index 000000000..6ddf917ba
--- /dev/null
+++ b/roms/edk2/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c
@@ -0,0 +1,41 @@
+/** @file
+  CPUID Leaf 0x15 for Core Crystal Clock frequency instance as Base Timer Library.
+
+  Copyright (c) 2019 Intel Corporation. All rights reserved.<BR>
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Base.h>
+#include <Library/TimerLib.h>
+#include <Library/BaseLib.h>
+
+/**
+  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
+  )
+{
+  return CpuidCoreClockCalculateTscFrequency ();
+}
+