diff options
Diffstat (limited to 'src/VBox/Devices/EFI/Firmware/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c')
-rw-r--r-- | src/VBox/Devices/EFI/Firmware/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c b/src/VBox/Devices/EFI/Firmware/UefiCpuPkg/Library/CpuTimerLib/BaseCpuTimerLib.c new file mode 100644 index 00000000..3b8d863a --- /dev/null +++ b/src/VBox/Devices/EFI/Firmware/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 (); +} + |