+EFI_STATUS\r
+EFIAPI\r
+WaitForTick (\r
+ IN EFI_METRONOME_ARCH_PROTOCOL *This,\r
+ IN UINT32 TickNumber\r
+ );\r
+\r
+/**\r
+ Interface structure for the Metronome Architectural Protocol.\r
+\r
+ @par Protocol Description:\r
+ This protocol provides access to a known time source in the platform to the\r
+ core. The core uses this known time source to produce core services that\r
+ require calibrated delays.\r
+\r
+ @param WaitForTick\r
+ Waits for a specified number of ticks from a known time source\r
+ in the platform. The actual time passed between entry of this\r
+ function and the first tick is between 0 and TickPeriod 100 nS\r
+ units. If you want to guarantee that at least TickPeriod time\r
+ has elapsed, wait for two ticks.\r
+\r
+ @param TickPeriod\r
+ The period of platform's known time source in 100 nS units.\r
+ This value on any platform must be at least 10 uS, and must not\r
+ exceed 200 uS. The value in this field is a constant that must\r
+ not be modified after the Metronome architectural protocol is\r
+ installed. All consumers must treat this as a read-only field.\r
+\r
+**/\r
+EFI_METRONOME_ARCH_PROTOCOL gMetronome = {\r
+ WaitForTick,\r
+ FixedPcdGet32 (PcdMetronomeTickPeriod)\r
+};\r