MdePkg/Library/BaseTimerLibNullTemplate/TimerLibNull.c

   1 /** @file
   2   A non-functional instance of the Timer Library.
   3
   4   Copyright (c) 2007 - 2008, Intel Corporation. All rights reserved.<BR>
   5   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 **/
  14
  15 #include <Base.h>
  16 #include <Library/TimerLib.h>
  17 #include <Library/DebugLib.h>
  18
  19 /**
  20   Stalls the CPU for at least the given number of microseconds.
  21
  22   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  23
  24   @param  MicroSeconds  The minimum number of microseconds to delay.
  25
  26   @return The value of MicroSeconds inputted.
  27
  28 **/
  29 UINTN
  30 EFIAPI
  31 MicroSecondDelay (
  32   IN      UINTN                     MicroSeconds
  33   )
  34 {
  35   ASSERT (FALSE);
  36   return MicroSeconds;
  37 }
  38
  39 /**
  40   Stalls the CPU for at least the given number of nanoseconds.
  41
  42   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  43
  44   @param  NanoSeconds The minimum number of nanoseconds to delay.
  45
  46   @return The value of NanoSeconds inputted.
  47
  48 **/
  49 UINTN
  50 EFIAPI
  51 NanoSecondDelay (
  52   IN      UINTN                     NanoSeconds
  53   )
  54 {
  55   ASSERT (FALSE);
  56   return 0;
  57 }
  58
  59 /**
  60   Retrieves the current value of a 64-bit free running performance counter.
  61
  62   The counter can either count up by 1 or count down by 1. If the physical
  63   performance counter counts by a larger increment, then the counter values
  64   must be translated. The properties of the counter can be retrieved from
  65   GetPerformanceCounterProperties().
  66
  67   @return The current value of the free running performance counter.
  68
  69 **/
  70 UINT64
  71 EFIAPI
  72 GetPerformanceCounter (
  73   VOID
  74   )
  75 {
  76   ASSERT (FALSE);
  77   return 0;
  78 }
  79
  80 /**
  81   Retrieves the 64-bit frequency in Hz and the range of performance counter
  82   values.
  83
  84   If StartValue is not NULL, then the value that the performance counter starts
  85   with immediately after is it rolls over is returned in StartValue. If
  86   EndValue is not NULL, then the value that the performance counter end with
  87   immediately before it rolls over is returned in EndValue. The 64-bit
  88   frequency of the performance counter in Hz is always returned. If StartValue
  89   is less than EndValue, then the performance counter counts up. If StartValue
  90   is greater than EndValue, then the performance counter counts down. For
  91   example, a 64-bit free running counter that counts up would have a StartValue
  92   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
  93   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
  94
  95   @param  StartValue  The value the performance counter starts with when it
  96                       rolls over.
  97   @param  EndValue    The value that the performance counter ends with before
  98                       it rolls over.
  99
 100   @return The frequency in Hz.
 101
 102 **/
 103 UINT64
 104 EFIAPI
 105 GetPerformanceCounterProperties (
 106   OUT      UINT64                    *StartValue,  OPTIONAL
 107   OUT      UINT64                    *EndValue     OPTIONAL
 108   )
 109 {
 110   ASSERT (FALSE);
 111
 112   return (UINT64)(-1);
 113 }