MdePkg/Library/BaseLib/Ebc/CpuBreakpoint.c

   1 /** @file
   2   Base Library CPU Functions for EBC
   3
   4   Copyright (c) 2006 - 2008, 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 **/
  14
  15 #include "BaseLibInternals.h"
  16
  17 extern
  18 UINT64
  19 _break (
  20   CHAR8 BreakCode
  21   );
  22
  23 /**
  24   Generates a breakpoint on the CPU.
  25
  26   Generates a breakpoint on the CPU. The breakpoint must be implemented such
  27   that code can resume normal execution after the breakpoint.
  28
  29 **/
  30 VOID
  31 EFIAPI
  32 CpuBreakpoint (
  33   VOID
  34   )
  35 {
  36   _break (3);
  37 }
  38
  39 /**
  40   Used to serialize load and store operations.
  41
  42   All loads and stores that proceed calls to this function are guaranteed to be
  43   globally visible when this function returns.
  44
  45 **/
  46 VOID
  47 EFIAPI
  48 MemoryFence (
  49   VOID
  50   )
  51 {
  52 }
  53
  54 /**
  55   Disables CPU interrupts.
  56
  57 **/
  58 VOID
  59 EFIAPI
  60 DisableInterrupts (
  61   VOID
  62   )
  63 {
  64   ASSERT (FALSE);
  65 }
  66
  67 /**
  68   Enables CPU interrupts.
  69
  70 **/
  71 VOID
  72 EFIAPI
  73 EnableInterrupts (
  74   VOID
  75   )
  76 {
  77   ASSERT (FALSE);
  78 }
  79
  80 /**
  81   Retrieves the current CPU interrupt state.
  82
  83   Returns TRUE is interrupts are currently enabled. Otherwise
  84   returns FALSE.
  85
  86   @retval TRUE  CPU interrupts are enabled.
  87   @retval FALSE CPU interrupts are disabled.
  88
  89 **/
  90 BOOLEAN
  91 EFIAPI
  92 GetInterruptState (
  93   VOID
  94   )
  95 {
  96   ASSERT (FALSE);
  97   return FALSE;
  98 }
  99
 100 /**
 101   Enables CPU interrupts for the smallest window required to capture any
 102   pending interrupts.
 103
 104 **/
 105 VOID
 106 EFIAPI
 107 EnableDisableInterrupts (
 108   VOID
 109   )
 110 {
 111   EnableInterrupts ();
 112   DisableInterrupts ();
 113 }
 114
 115 /**
 116   Requests CPU to pause for a short period of time.
 117
 118   Requests CPU to pause for a short period of time. Typically used in MP
 119   systems to prevent memory starvation while waiting for a spin lock.
 120
 121 **/
 122 VOID
 123 EFIAPI
 124 CpuPause (
 125   VOID
 126   )
 127 {
 128 }
 129