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Diffstat (limited to 'MdePkg/Include/Protocol/Timestamp.h')
-rw-r--r-- | MdePkg/Include/Protocol/Timestamp.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/MdePkg/Include/Protocol/Timestamp.h b/MdePkg/Include/Protocol/Timestamp.h new file mode 100644 index 0000000000..9be72426e6 --- /dev/null +++ b/MdePkg/Include/Protocol/Timestamp.h @@ -0,0 +1,101 @@ +/** @file
+ EFI Timestamp Protocol as defined in UEFI2.4 Specification.
+ Used to provide a platform independent interface for retrieving a high resolution timestamp counter.
+
+ Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+ @par Revision Reference:
+ This Protocol is introduced in UEFI Specification 2.4
+
+**/
+
+#ifndef __EFI_TIME_STAMP_PROTOCOL_H__
+#define __EFI_TIME_STAMP_PROTOCOL_H__
+
+
+#define EFI_TIMESTAMP_PROTOCOL_GUID \
+ { 0xafbfde41, 0x2e6e, 0x4262, {0xba, 0x65, 0x62, 0xb9, 0x23, 0x6e, 0x54, 0x95 } }
+
+///
+/// Declare forward reference for the Time Stamp Protocol
+///
+typedef struct _EFI_TIMESTAMP_PROTOCOL EFI_TIMESTAMP_PROTOCOL;
+
+///
+/// EFI_TIMESTAMP_PROPERTIES
+///
+typedef struct {
+ ///
+ /// The frequency of the timestamp counter in Hz.
+ ///
+ UINT64 Frequency;
+ ///
+ /// The value that the timestamp counter ends with immediately before it rolls over.
+ /// For example, a 64-bit free running counter would have an EndValue of 0xFFFFFFFFFFFFFFFF.
+ /// A 24-bit free running counter would have an EndValue of 0xFFFFFF.
+ ///
+ UINT64 EndValue;
+} EFI_TIMESTAMP_PROPERTIES;
+
+/**
+ 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.
+
+ @param None.
+
+ @retval The current value of the free running timestamp counter.
+
+**/
+typedef
+UINT64
+(EFIAPI *TIMESTAMP_GET)(
+ VOID
+ );
+
+/**
+ Obtains timestamp counter properties including frequency and value limits.
+
+ @param[out] Properties The properties of the timestamp counter.
+
+ @retval EFI_SUCCESS The properties were successfully retrieved.
+ @retval EFI_DEVICE_ERROR An error occurred trying to retrieve the properties of the timestamp
+ counter subsystem. Properties is not pedated.
+ @retval EFI_INVALID_PARAMETER Properties is NULL.
+
+**/
+typedef
+EFI_STATUS
+(EFIAPI *TIMESTAMP_GET_PROPERTIES)(
+ OUT EFI_TIMESTAMP_PROPERTIES *Properties
+ );
+
+
+
+///
+/// EFI_TIMESTAMP_PROTOCOL
+/// The protocol provides a platform independent interface for retrieving a high resolution
+/// timestamp counter.
+///
+struct _EFI_TIMESTAMP_PROTOCOL {
+ TIMESTAMP_GET GetTimestamp;
+ TIMESTAMP_GET_PROPERTIES GetProperties;
+};
+
+extern EFI_GUID gEfiTimestampProtocolGuid;
+
+#endif
+
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