MdeModulePkg/Include/Library/ResetUtilityLib.h

   1 /** @file
   2   This header describes various helper functions for resetting the system.
   3
   4   Copyright (c) 2017 Intel Corporation. All rights reserved.<BR>
   5   Copyright (c) 2016 Microsoft Corporation. All rights reserved.<BR>
   6
   7   SPDX-License-Identifier: BSD-2-Clause-Patent
   8
   9 **/
  10 #ifndef _RESET_UTILITY_LIB_H_
  11 #define _RESET_UTILITY_LIB_H_
  12
  13 /**
  14   This is a shorthand helper function to reset with a subtype so that
  15   the caller doesn't have to bother with a function that has half a dozen
  16   parameters.
  17
  18   This will generate a reset with status EFI_SUCCESS, a NULL string, and
  19   no custom data. The subtype will be formatted in such a way that it can be
  20   picked up by notification registrations and custom handlers.
  21
  22   NOTE: This call will fail if the architectural ResetSystem underpinnings
  23         are not initialized. For DXE, you can add gEfiResetArchProtocolGuid
  24         to your DEPEX.
  25
  26   @param[in]  ResetSubtype  GUID pointer for the reset subtype to be used.
  27
  28 **/
  29 VOID
  30 EFIAPI
  31 ResetPlatformSpecificGuid (
  32   IN CONST  GUID        *ResetSubtype
  33   );
  34
  35 /**
  36   This function examines the DataSize and ResetData parameters passed to
  37   to ResetSystem() and detemrines if the ResetData contains a Null-terminated
  38   Unicode string followed by a GUID specific subtype.  If the GUID specific
  39   subtype is present, then a pointer to the GUID value in ResetData is returned.
  40
  41   @param[in]  DataSize    The size, in bytes, of ResetData.
  42   @param[in]  ResetData   Pointer to the data buffer passed into ResetSystem().
  43
  44   @retval     Pointer     Pointer to the GUID value in ResetData.
  45   @retval     NULL        ResetData is NULL.
  46   @retval     NULL        ResetData does not start with a Null-terminated
  47                           Unicode string.
  48   @retval     NULL        A Null-terminated Unicode string is present, but there
  49                           are less than sizeof (GUID) bytes after the string.
  50   @retval     NULL        No subtype is found.
  51
  52 **/
  53 GUID *
  54 EFIAPI
  55 GetResetPlatformSpecificGuid (
  56   IN UINTN       DataSize,
  57   IN CONST VOID  *ResetData
  58   );
  59
  60 /**
  61   This is a helper function that creates the reset data buffer that can be
  62   passed into ResetSystem().
  63
  64   The reset data buffer is returned in ResetData and contains ResetString
  65   followed by the ResetSubtype GUID followed by the ExtraData.
  66
  67   NOTE: Strings are internally limited by MAX_UINT16.
  68
  69   @param[in, out] ResetDataSize  On input, the size of the ResetData buffer. On
  70                                  output, either the total number of bytes
  71                                  copied, or the required buffer size.
  72   @param[in, out] ResetData      A pointer to the buffer in which to place the
  73                                  final structure.
  74   @param[in]      ResetSubtype   Pointer to the GUID specific subtype.  This
  75                                  parameter is optional and may be NULL.
  76   @param[in]      ResetString    Pointer to a Null-terminated Unicode string
  77                                  that describes the reset.  This parameter is
  78                                  optional and may be NULL.
  79   @param[in]      ExtraDataSize  The size, in bytes, of ExtraData buffer.
  80   @param[in]      ExtraData      Pointer to a buffer of extra data.  This
  81                                  parameter is optional and may be NULL.
  82
  83   @retval     RETURN_SUCCESS             ResetDataSize and ResetData are updated.
  84   @retval     RETURN_INVALID_PARAMETER   ResetDataSize is NULL.
  85   @retval     RETURN_INVALID_PARAMETER   ResetData is NULL.
  86   @retval     RETURN_INVALID_PARAMETER   ExtraData was provided without a
  87                                          ResetSubtype. This is not supported by the
  88                                          UEFI spec.
  89   @retval     RETURN_BUFFER_TOO_SMALL    An insufficient buffer was provided.
  90                                          ResetDataSize is updated with minimum size
  91                                          required.
  92 **/
  93 RETURN_STATUS
  94 EFIAPI
  95 BuildResetData (
  96   IN OUT   UINTN     *ResetDataSize,
  97   IN OUT   VOID      *ResetData,
  98   IN CONST GUID      *ResetSubtype  OPTIONAL,
  99   IN CONST CHAR16    *ResetString   OPTIONAL,
 100   IN       UINTN     ExtraDataSize  OPTIONAL,
 101   IN CONST VOID      *ExtraData     OPTIONAL
 102   );
 103
 104 #endif // _RESET_UTILITY_LIB_H_