MdePkg/Library/BaseTimerLibLocalApic/Ebc/EbcTimerLib.c

   1 /** @file
   2   Timer Library functions for EBC.
   3
   4   Copyright (c) 2006, 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:  EbcTimerLib.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   //
  34   // EBC architecture does not support local APIC timer.
  35   //
  36   ASSERT (FALSE);
  37   return MicroSeconds;
  38 }
  39
  40 /**
  41   Stalls the CPU for at least the given number of nanoseconds.
  42
  43   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  44
  45   @param  NanoSeconds The minimum number of nanoseconds to delay.
  46
  47   @return NanoSeconds
  48
  49 **/
  50 UINTN
  51 EFIAPI
  52 NanoSecondDelay (
  53   IN      UINTN                     NanoSeconds
  54   )
  55 {
  56   //
  57   // EBC architecture does not support local APIC timer.
  58   //
  59   ASSERT (FALSE);
  60   return NanoSeconds;
  61 }
  62
  63 /**
  64   Retrieves the current value of a 64-bit free running performance counter.
  65
  66   Retrieves the current value of a 64-bit free running performance counter. The
  67   counter can either count up by 1 or count down by 1. If the physical
  68   performance counter counts by a larger increment, then the counter values
  69   must be translated. The properties of the counter can be retrieved from
  70   GetPerformanceCounterProperties().
  71
  72   @return The current value of the free running performance counter.
  73
  74 **/
  75 UINT64
  76 EFIAPI
  77 GetPerformanceCounter (
  78   VOID
  79   )
  80 {
  81   //
  82   // EBC architecture does not support local APIC timer.
  83   //
  84   ASSERT (FALSE);
  85   return 0;
  86 }
  87
  88 /**
  89   Retrieves the 64-bit frequency in Hz and the range of performance counter
  90   values.
  91
  92   If StartValue is not NULL, then the value that the performance counter starts
  93   with immediately after is it rolls over is returned in StartValue. If
  94   EndValue is not NULL, then the value that the performance counter end with
  95   immediately before it rolls over is returned in EndValue. The 64-bit
  96   frequency of the performance counter in Hz is always returned. If StartValue
  97   is less than EndValue, then the performance counter counts up. If StartValue
  98   is greater than EndValue, then the performance counter counts down. For
  99   example, a 64-bit free running counter that counts up would have a StartValue
 100   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 101   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 102
 103   @param  StartValue  The value the performance counter starts with when it
 104                       rolls over.
 105   @param  EndValue    The value that the performance counter ends with before
 106                       it rolls over.
 107
 108   @return The frequency in Hz.
 109
 110 **/
 111 UINT64
 112 EFIAPI
 113 GetPerformanceCounterProperties (
 114   OUT      UINT64                    *StartValue,  OPTIONAL
 115   OUT      UINT64                    *EndValue     OPTIONAL
 116   )
 117 {
 118   //
 119   // EBC architecture does not support local APIC timer.
 120   //
 121   ASSERT (FALSE);
 122   return 0;
 123 }