+/**\r
+ Returns a timer value from one of the CPU's internal timers. There is no\r
+ inherent time interval between ticks but is a function of the CPU frequency.\r
+\r
+ @param This - Protocol instance structure.\r
+ @param TimerIndex - Specifies which CPU timer is requested.\r
+ @param TimerValue - Pointer to the returned timer value.\r
+ @param TimerPeriod - A pointer to the amount of time that passes\r
+ in femtoseconds (10-15) for each increment\r
+ of TimerValue. If TimerValue does not\r
+ increment at a predictable rate, then 0 is\r
+ returned. The amount of time that has\r
+ passed between two calls to GetTimerValue()\r
+ can be calculated with the formula\r
+ (TimerValue2 - TimerValue1) * TimerPeriod.\r
+ This parameter is optional and may be NULL.\r
+\r
+ @retval EFI_SUCCESS - If the CPU timer count was returned.\r
+ @retval EFI_UNSUPPORTED - If the CPU does not have any readable timers.\r
+ @retval EFI_DEVICE_ERROR - If an error occurred while reading the timer.\r
+ @retval EFI_INVALID_PARAMETER - TimerIndex is not valid or TimerValue is NULL.\r
+\r
+**/\r