OvmfPkg/Library/ResetSystemLib/ResetSystemLib.c

   1 /** @file
   2   Reset System Library functions for OVMF
   3
   4   Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #include <Base.h>                   // BIT1
  10
  11 #include <Library/BaseLib.h>        // CpuDeadLoop()
  12 #include <Library/IoLib.h>          // IoWrite8()
  13 #include <Library/ResetSystemLib.h> // ResetCold()
  14 #include <Library/TimerLib.h>       // MicroSecondDelay()
  15
  16 /**
  17   Calling this function causes a system-wide reset. This sets
  18   all circuitry within the system to its initial state. This type of reset
  19   is asynchronous to system operation and operates without regard to
  20   cycle boundaries.
  21
  22   System reset should not return, if it returns, it means the system does
  23   not support cold reset.
  24 **/
  25 VOID
  26 EFIAPI
  27 ResetCold (
  28   VOID
  29   )
  30 {
  31   IoWrite8 (0xCF9, BIT2 | BIT1); // 1st choice: PIIX3 RCR, RCPU|SRST
  32   MicroSecondDelay (50);
  33
  34   IoWrite8 (0x64, 0xfe);         // 2nd choice: keyboard controller
  35   CpuDeadLoop ();
  36 }
  37
  38 /**
  39   Calling this function causes a system-wide initialization. The processors
  40   are set to their initial state, and pending cycles are not corrupted.
  41
  42   System reset should not return, if it returns, it means the system does
  43   not support warm reset.
  44 **/
  45 VOID
  46 EFIAPI
  47 ResetWarm (
  48   VOID
  49   )
  50 {
  51   IoWrite8 (0x64, 0xfe);
  52   CpuDeadLoop ();
  53 }
  54
  55
  56 /**
  57   This function causes a systemwide reset. The exact type of the reset is
  58   defined by the EFI_GUID that follows the Null-terminated Unicode string
  59   passed into ResetData. If the platform does not recognize the EFI_GUID in
  60   ResetData the platform must pick a supported reset type to perform.The
  61   platform may optionally log the parameters from any non-normal reset that
  62   occurs.
  63
  64   @param[in]  DataSize   The size, in bytes, of ResetData.
  65   @param[in]  ResetData  The data buffer starts with a Null-terminated string,
  66                          followed by the EFI_GUID.
  67 **/
  68 VOID
  69 EFIAPI
  70 ResetPlatformSpecific (
  71   IN UINTN   DataSize,
  72   IN VOID    *ResetData
  73   )
  74 {
  75   ResetCold ();
  76 }
  77
  78 /**
  79   The ResetSystem function resets the entire platform.
  80
  81   @param[in] ResetType      The type of reset to perform.
  82   @param[in] ResetStatus    The status code for the reset.
  83   @param[in] DataSize       The size, in bytes, of ResetData.
  84   @param[in] ResetData      For a ResetType of EfiResetCold, EfiResetWarm, or
  85                             EfiResetShutdown the data buffer starts with a
  86                             Null-terminated string, optionally followed by
  87                             additional binary data. The string is a description
  88                             that the caller may use to further indicate the
  89                             reason for the system reset.
  90 **/
  91 VOID
  92 EFIAPI
  93 ResetSystem (
  94   IN EFI_RESET_TYPE               ResetType,
  95   IN EFI_STATUS                   ResetStatus,
  96   IN UINTN                        DataSize,
  97   IN VOID                         *ResetData OPTIONAL
  98   )
  99 {
 100   switch (ResetType) {
 101   case EfiResetWarm:
 102     ResetWarm ();
 103     break;
 104
 105   case EfiResetCold:
 106     ResetCold ();
 107     break;
 108
 109   case EfiResetShutdown:
 110     ResetShutdown ();
 111     break;
 112
 113   case EfiResetPlatformSpecific:
 114     ResetPlatformSpecific (DataSize, ResetData);
 115     break;
 116
 117   default:
 118     break;
 119   }
 120 }