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   This function causes a systemwide reset. The exact type of the reset is
  57   defined by the EFI_GUID that follows the Null-terminated Unicode string
  58   passed into ResetData. If the platform does not recognize the EFI_GUID in
  59   ResetData the platform must pick a supported reset type to perform.The
  60   platform may optionally log the parameters from any non-normal reset that
  61   occurs.
  62
  63   @param[in]  DataSize   The size, in bytes, of ResetData.
  64   @param[in]  ResetData  The data buffer starts with a Null-terminated string,
  65                          followed by the EFI_GUID.
  66 **/
  67 VOID
  68 EFIAPI
  69 ResetPlatformSpecific (
  70   IN UINTN  DataSize,
  71   IN VOID   *ResetData
  72   )
  73 {
  74   ResetCold ();
  75 }
  76
  77 /**
  78   The ResetSystem function resets the entire platform.
  79
  80   @param[in] ResetType      The type of reset to perform.
  81   @param[in] ResetStatus    The status code for the reset.
  82   @param[in] DataSize       The size, in bytes, of ResetData.
  83   @param[in] ResetData      For a ResetType of EfiResetCold, EfiResetWarm, or
  84                             EfiResetShutdown the data buffer starts with a
  85                             Null-terminated string, optionally followed by
  86                             additional binary data. The string is a description
  87                             that the caller may use to further indicate the
  88                             reason for the system reset.
  89 **/
  90 VOID
  91 EFIAPI
  92 ResetSystem (
  93   IN EFI_RESET_TYPE  ResetType,
  94   IN EFI_STATUS      ResetStatus,
  95   IN UINTN           DataSize,
  96   IN VOID            *ResetData OPTIONAL
  97   )
  98 {
  99   switch (ResetType) {
 100     case EfiResetWarm:
 101       ResetWarm ();
 102       break;
 103
 104     case EfiResetCold:
 105       ResetCold ();
 106       break;
 107
 108     case EfiResetShutdown:
 109       ResetShutdown ();
 110       break;
 111
 112     case EfiResetPlatformSpecific:
 113       ResetPlatformSpecific (DataSize, ResetData);
 114       break;
 115
 116     default:
 117       break;
 118   }
 119 }