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git.proxmox.com Git - mirror_edk2.git/blob - MdePkg/Library/BaseTimerLibNullTemplate/TimerLibNull.c
2 A non-functional instance of the Timer Library.
4 Copyright (c) 2007, Intel Corporation<BR>
5 All rights reserved. This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
19 #include <Library/TimerLib.h>
20 #include <Library/DebugLib.h>
23 Stalls the CPU for at least the given number of microseconds.
25 Stalls the CPU for the number of microseconds specified by MicroSeconds.
27 @param MicroSeconds The minimum number of microseconds to delay.
43 Stalls the CPU for at least the given number of nanoseconds.
45 Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
47 @param NanoSeconds The minimum number of nanoseconds to delay.
63 Retrieves the current value of a 64-bit free running performance counter.
65 Retrieves the current value of a 64-bit free running performance counter. The
66 counter can either count up by 1 or count down by 1. If the physical
67 performance counter counts by a larger increment, then the counter values
68 must be translated. The properties of the counter can be retrieved from
69 GetPerformanceCounterProperties().
71 @return The current value of the free running performance counter.
76 GetPerformanceCounter (
85 Retrieves the 64-bit frequency in Hz and the range of performance counter
88 If StartValue is not NULL, then the value that the performance counter starts
89 with immediately after is it rolls over is returned in StartValue. If
90 EndValue is not NULL, then the value that the performance counter end with
91 immediately before it rolls over is returned in EndValue. The 64-bit
92 frequency of the performance counter in Hz is always returned. If StartValue
93 is less than EndValue, then the performance counter counts up. If StartValue
94 is greater than EndValue, then the performance counter counts down. For
95 example, a 64-bit free running counter that counts up would have a StartValue
96 of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
97 that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
99 @param StartValue The value the performance counter starts with when it
101 @param EndValue The value that the performance counter ends with before
104 @return The frequency in Hz.
109 GetPerformanceCounterProperties (
110 OUT UINT64
*StartValue
, OPTIONAL
111 OUT UINT64
*EndValue OPTIONAL