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 // The package level header files this module uses
  19 //
  20 #include <Base.h>
  21 //
  22 // The protocols, PPI and GUID defintions for this module
  23 //
  24 //
  25 // The Library classes this module consumes
  26 //
  27 #include <Library/TimerLib.h>
  28 #include <Library/DebugLib.h>
  29
  30 /**
  31   Stalls the CPU for at least the given number of microseconds.
  32
  33   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  34
  35   @param  MicroSeconds  The minimum number of microseconds to delay.
  36
  37   @return MicroSeconds
  38
  39 **/
  40 UINTN
  41 EFIAPI
  42 MicroSecondDelay (
  43   IN      UINTN                     MicroSeconds
  44   )
  45 {
  46   ASSERT (FALSE);
  47   return MicroSeconds;
  48 }
  49
  50 /**
  51   Stalls the CPU for at least the given number of nanoseconds.
  52
  53   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  54
  55   @param  NanoSeconds The minimum number of nanoseconds to delay.
  56
  57   @return NanoSeconds
  58
  59 **/
  60 UINTN
  61 EFIAPI
  62 NanoSecondDelay (
  63   IN      UINTN                     NanoSeconds
  64   )
  65 {
  66   ASSERT (FALSE);
  67   return 0;
  68 }
  69
  70 /**
  71   Retrieves the current value of a 64-bit free running performance counter.
  72
  73   Retrieves the current value of a 64-bit free running performance counter. The
  74   counter can either count up by 1 or count down by 1. If the physical
  75   performance counter counts by a larger increment, then the counter values
  76   must be translated. The properties of the counter can be retrieved from
  77   GetPerformanceCounterProperties().
  78
  79   @return The current value of the free running performance counter.
  80
  81 **/
  82 UINT64
  83 EFIAPI
  84 GetPerformanceCounter (
  85   VOID
  86   )
  87 {
  88   ASSERT (FALSE);
  89   return 0;
  90 }
  91
  92 /**
  93   Retrieves the 64-bit frequency in Hz and the range of performance counter
  94   values.
  95
  96   If StartValue is not NULL, then the value that the performance counter starts
  97   with immediately after is it rolls over is returned in StartValue. If
  98   EndValue is not NULL, then the value that the performance counter end with
  99   immediately before it rolls over is returned in EndValue. The 64-bit
 100   frequency of the performance counter in Hz is always returned. If StartValue
 101   is less than EndValue, then the performance counter counts up. If StartValue
 102   is greater than EndValue, then the performance counter counts down. For
 103   example, a 64-bit free running counter that counts up would have a StartValue
 104   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 105   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 106
 107   @param  StartValue  The value the performance counter starts with when it
 108                       rolls over.
 109   @param  EndValue    The value that the performance counter ends with before
 110                       it rolls over.
 111
 112   @return The frequency in Hz.
 113
 114 **/
 115 UINT64
 116 EFIAPI
 117 GetPerformanceCounterProperties (
 118   OUT      UINT64                    *StartValue,  OPTIONAL
 119   OUT      UINT64                    *EndValue     OPTIONAL
 120   )
 121 {
 122   ASSERT (FALSE);
 123   return 0;
 124 }