MdePkg/Library/BaseTimerLibNullTemplate/TimerLibNull.c

   1 /** @file
   2   A non-functional instance of the Timer Library.
   3
   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
   9
  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.
  12
  13   Module Name:  TimerLibNull.c
  14
  15 **/
  16
  17 /**
  18   Stalls the CPU for at least the given number of microseconds.
  19
  20   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  21
  22   @param  MicroSeconds  The minimum number of microseconds to delay.
  23
  24   @return MicroSeconds
  25
  26 **/
  27 UINTN
  28 EFIAPI
  29 MicroSecondDelay (
  30   IN      UINTN                     MicroSeconds
  31   )
  32 {
  33   ASSERT (FALSE);
  34   return MicroSeconds;
  35 }
  36
  37 /**
  38   Stalls the CPU for at least the given number of nanoseconds.
  39
  40   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  41
  42   @param  NanoSeconds The minimum number of nanoseconds to delay.
  43
  44   @return NanoSeconds
  45
  46 **/
  47 UINTN
  48 EFIAPI
  49 NanoSecondDelay (
  50   IN      UINTN                     NanoSeconds
  51   )
  52 {
  53   ASSERT (FALSE);
  54   return 0;
  55 }
  56
  57 /**
  58   Retrieves the current value of a 64-bit free running performance counter.
  59
  60   Retrieves the current value of a 64-bit free running performance counter. The
  61   counter can either count up by 1 or count down by 1. If the physical
  62   performance counter counts by a larger increment, then the counter values
  63   must be translated. The properties of the counter can be retrieved from
  64   GetPerformanceCounterProperties().
  65
  66   @return The current value of the free running performance counter.
  67
  68 **/
  69 UINT64
  70 EFIAPI
  71 GetPerformanceCounter (
  72   VOID
  73   )
  74 {
  75   ASSERT (FALSE);
  76   return 0;
  77 }
  78
  79 /**
  80   Retrieves the 64-bit frequency in Hz and the range of performance counter
  81   values.
  82
  83   If StartValue is not NULL, then the value that the performance counter starts
  84   with immediately after is it rolls over is returned in StartValue. If
  85   EndValue is not NULL, then the value that the performance counter end with
  86   immediately before it rolls over is returned in EndValue. The 64-bit
  87   frequency of the performance counter in Hz is always returned. If StartValue
  88   is less than EndValue, then the performance counter counts up. If StartValue
  89   is greater than EndValue, then the performance counter counts down. For
  90   example, a 64-bit free running counter that counts up would have a StartValue
  91   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
  92   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
  93
  94   @param  StartValue  The value the performance counter starts with when it
  95                       rolls over.
  96   @param  EndValue    The value that the performance counter ends with before
  97                       it rolls over.
  98
  99   @return The frequency in Hz.
 100
 101 **/
 102 UINT64
 103 EFIAPI
 104 GetPerformanceCounterProperties (
 105   OUT      UINT64                    *StartValue,  OPTIONAL
 106   OUT      UINT64                    *EndValue     OPTIONAL
 107   )
 108 {
 109   ASSERT (FALSE);
 110   return 0;
 111 }