TimestampDxe.c File Reference

#include <Uefi.h>
#include <Library/DebugLib.h>
#include <Library/UefiDriverEntryPoint.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/TimerLib.h>
#include <Library/BaseMemoryLib.h>
#include <Protocol/Timestamp.h>

Go to the source code of this file.

Functions
UINT64 EFIAPI	TimestampDriverGetTimestamp (VOID)
EFI_STATUS EFIAPI	TimestampDriverGetProperties (OUT EFI_TIMESTAMP_PROPERTIES *Properties)
EFI_STATUS EFIAPI	TimestampDriverInitialize (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
UINT64	mTimerLibStartValue = 0
UINT64	mTimerLibEndValue = 0
EFI_TIMESTAMP_PROPERTIES	mTimestampProperties
EFI_TIMESTAMP_PROTOCOL	mTimestamp

Detailed Description

Implementation of Timestamp Protocol using UEFI APIs.

Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file TimestampDxe.c.

Function Documentation

TimestampDriverGetProperties()

EFI_STATUS EFIAPI TimestampDriverGetProperties

(

OUT EFI_TIMESTAMP_PROPERTIES *

Properties

)

Obtains timestamp counter properties including frequency and value limits.

Parameters

[out]

Properties

The properties of the timestamp counter.

Return values

EFI_SUCCESS	The properties were successfully retrieved.
EFI_DEVICE_ERROR	An error occurred trying to retrieve the properties of the timestamp counter subsystem. Properties is not pedated.
EFI_INVALID_PARAMETER	Properties is NULL.

Definition at line 87 of file TimestampDxe.c.

TimestampDriverGetTimestamp()

UINT64 EFIAPI TimestampDriverGetTimestamp

(

VOID

)

Retrieves the current value of a 64-bit free running timestamp counter.

The counter shall count up in proportion to the amount of time that has passed. The counter value will always roll over to zero. The properties of the counter can be retrieved from GetProperties(). The caller should be prepared for the function to return the same value twice across successive calls. The counter value will not go backwards other than when wrapping, as defined by EndValue in GetProperties(). The frequency of the returned timestamp counter value must remain constant. Power management operations that affect clocking must not change the returned counter frequency. The quantization of counter value updates may vary as long as the value reflecting time passed remains consistent.

Return values

The	current value of the free running timestamp counter.

Definition at line 51 of file TimestampDxe.c.

TimestampDriverInitialize()

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

Entry point of the Timestamp Protocol driver.

Parameters

ImageHandle	The image handle of this driver.
SystemTable	The pointer of EFI_SYSTEM_TABLE.

Return values

EFI_SUCCESS

Watchdog Timer Architectural Protocol successfully installed.

Definition at line 122 of file TimestampDxe.c.

Variable Documentation

mTimerLibEndValue

UINT64 mTimerLibEndValue = 0

Definition at line 25 of file TimestampDxe.c.

mTimerLibStartValue

UINT64 mTimerLibStartValue = 0

Definition at line 20 of file TimestampDxe.c.

mTimestamp

EFI_TIMESTAMP_PROTOCOL mTimestamp

Initial value:

= {
  TimestampDriverGetTimestamp,
  TimestampDriverGetProperties
}

Definition at line 106 of file TimestampDxe.c.

mTimestampProperties

EFI_TIMESTAMP_PROPERTIES mTimestampProperties

Initial value:

= {
  0,
  0
}

Definition at line 30 of file TimestampDxe.c.