#include "Metronome.h"

Functions
EFI_STATUS EFIAPI	WaitForTick (IN EFI_METRONOME_ARCH_PROTOCOL *This, IN UINT32 TickNumber)

EFI_STATUS EFIAPI	InstallMetronome (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
EFI_HANDLE	mMetronomeHandle = NULL

EFI_METRONOME_ARCH_PROTOCOL	mMetronome

Detailed Description

Produces the Metronome Architectural Protocol on top of Timer Library.

This is a generic implementation of the Metronome Architectural Protocol that layers on top of an instance of the Timer Library. The Timer Library provides functions for nanosecond and microsecond delays. This generic implementation produces a fixed TickPeriod of 1 100ns unit, and when the WaitForTick() service is called, the number of ticks passed in is converted to either nanosecond or microsecond units. If the number of ticks is small, then nanoseconds are used. If the number of ticks is large, then microseconds are used. This prevents overflows that could occur for long delays if only nanoseconds were used and also provides the greatest accuracy for small delays.

Copyright (c) 2008 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file Metronome.c.

Function Documentation

◆ InstallMetronome()

EFI_STATUS EFIAPI InstallMetronome	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

The user Entry Point for module Metronome. The user code starts with this function.

Parameters

[in]	ImageHandle	The firmware allocated handle for the EFI image.
[in]	SystemTable	A pointer to the EFI System Table.

Return values

EFI_SUCCESS	The entry point is executed successfully.
other	Some error occurs when executing this entry point.

Definition at line 97 of file Metronome.c.

◆ WaitForTick()

EFI_STATUS EFIAPI WaitForTick	(	IN EFI_METRONOME_ARCH_PROTOCOL *	This,
		IN UINT32	TickNumber
	)

Waits for the specified number of ticks.

This function implements EFI_METRONOME_ARCH_PROTOCOL.WaitForTick(). The WaitForTick() function waits for the number of ticks specified by TickNumber from a known time source in the platform. If TickNumber of ticks are detected, then EFI_SUCCESS is returned. The actual time passed between entry of this function and the first tick is between 0 and TickPeriod 100 nS units. If you want to guarantee that at least TickPeriod time has elapsed, wait for two ticks. This function waits for a hardware event to determine when a tick occurs. It is possible for interrupt processing, or exception processing to interrupt the execution of the WaitForTick() function. Depending on the hardware source for the ticks, it is possible for a tick to be missed. This function cannot guarantee that ticks will not be missed. If a timeout occurs waiting for the specified number of ticks, then EFI_TIMEOUT is returned.

Parameters

This	The EFI_METRONOME_ARCH_PROTOCOL instance.
TickNumber	Number of ticks to wait.

Return values

EFI_SUCCESS	The wait for the number of ticks specified by TickNumber succeeded.
EFI_TIMEOUT	A timeout occurred waiting for the specified number of ticks.

Definition at line 61 of file Metronome.c.

Variable Documentation

◆ mMetronome

EFI_METRONOME_ARCH_PROTOCOL mMetronome

Initial value:

= {
  WaitForTick,
  1  
}

Definition at line 29 of file Metronome.c.

◆ mMetronomeHandle

EFI_HANDLE mMetronomeHandle = NULL

Definition at line 24 of file Metronome.c.

Functions