IntelFrameworkModulePkg/Universal/LegacyRegionDxe/LegacyRegion.c

   1 /** @file
   2   Produces the Legacy Region Protocol.
   3
   4   This generic implementation of the Legacy Region Protocol does not actually
   5   perform any lock/unlock operations.  This module may be used on platforms
   6   that do not provide HW locking of the legacy memory regions.  It can also
   7   be used as a template driver for implementing the Legacy Region Protocol on
   8   a platform that does support HW locking of the legacy memory regions.
   9
  10 Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.<BR>
  11 SPDX-License-Identifier: BSD-2-Clause-Patent
  12
  13 **/
  14
  15 #include <PiDxe.h>
  16 #include <Protocol/LegacyRegion.h>
  17 #include <Library/DebugLib.h>
  18 #include <Library/UefiBootServicesTableLib.h>
  19
  20 /**
  21   Sets hardware to decode or not decode a region.
  22
  23   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
  24   @param  Start                 Start of region to decode.
  25   @param  Length                Size in bytes of the region.
  26   @param  On                    Decode/nondecode flag.
  27
  28   @retval EFI_SUCCESS           Decode range successfully changed.
  29
  30 **/
  31 EFI_STATUS
  32 EFIAPI
  33 LegacyRegionDecode (
  34   IN EFI_LEGACY_REGION_PROTOCOL  *This,
  35   IN UINT32                      Start,
  36   IN UINT32                      Length,
  37   IN BOOLEAN                     *On
  38   )
  39 {
  40   return EFI_SUCCESS;
  41 }
  42
  43 /**
  44   Sets a region to read only.
  45
  46   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
  47   @param  Start                 Start of region to lock.
  48   @param  Length                Size in bytes of the region.
  49   @param  Granularity           Lock attribute affects this granularity in bytes.
  50
  51   @retval EFI_SUCCESS           The region was made read only.
  52
  53 **/
  54 EFI_STATUS
  55 EFIAPI
  56 LegacyRegionLock (
  57   IN  EFI_LEGACY_REGION_PROTOCOL  *This,
  58   IN  UINT32                      Start,
  59   IN  UINT32                      Length,
  60   OUT UINT32                      *Granularity OPTIONAL
  61   )
  62 {
  63   return EFI_SUCCESS;
  64 }
  65
  66 /**
  67   Sets a region to read only and ensures that flash is locked from being
  68   inadvertently modified.
  69
  70   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
  71   @param  Start                 Start of region to lock.
  72   @param  Length                Size in bytes of the region.
  73   @param  Granularity           Lock attribute affects this granularity in bytes.
  74
  75   @retval EFI_SUCCESS           The region was made read only and flash is locked.
  76
  77 **/
  78 EFI_STATUS
  79 EFIAPI
  80 LegacyRegionBootLock (
  81   IN  EFI_LEGACY_REGION_PROTOCOL  *This,
  82   IN  UINT32                      Start,
  83   IN  UINT32                      Length,
  84   OUT UINT32                      *Granularity OPTIONAL
  85   )
  86 {
  87   return EFI_SUCCESS;
  88 }
  89
  90 /**
  91   Sets a region to read-write.
  92
  93   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
  94   @param  Start                 Start of region to lock.
  95   @param  Length                Size in bytes of the region.
  96   @param  Granularity           Lock attribute affects this granularity in bytes.
  97
  98   @retval EFI_SUCCESS           The region was successfully made read-write.
  99
 100 **/
 101 EFI_STATUS
 102 EFIAPI
 103 LegacyRegionUnlock (
 104   IN  EFI_LEGACY_REGION_PROTOCOL  *This,
 105   IN  UINT32                      Start,
 106   IN  UINT32                      Length,
 107   OUT UINT32                      *Granularity OPTIONAL
 108   )
 109 {
 110   return EFI_SUCCESS;
 111 }
 112
 113 //
 114 // Module global for the handle the Legacy Region Protocol is installed
 115 //
 116 EFI_HANDLE                  mLegacyRegionHandle = NULL;
 117
 118 //
 119 // Module global for the Legacy Region Protocol instance that is installed onto
 120 // mLegacyRegionHandle
 121 //
 122 EFI_LEGACY_REGION_PROTOCOL  mLegacyRegion = {
 123   LegacyRegionDecode,
 124   LegacyRegionLock,
 125   LegacyRegionBootLock,
 126   LegacyRegionUnlock
 127 };
 128
 129 /**
 130   The user Entry Point for module LegacyRegionDxe.  The user code starts with this function.
 131
 132   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
 133   @param[in] SystemTable    A pointer to the EFI System Table.
 134
 135   @retval EFI_SUCCESS       The entry point is executed successfully.
 136   @retval other             Some error occurs when executing this entry point.
 137
 138 **/
 139 EFI_STATUS
 140 EFIAPI
 141 LegacyRegionInstall (
 142   IN EFI_HANDLE        ImageHandle,
 143   IN EFI_SYSTEM_TABLE  *SystemTable
 144   )
 145 {
 146   EFI_STATUS  Status;
 147
 148   //
 149   // Make sure the Legacy Region Protocol is not already installed in the system
 150   //
 151   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiLegacyRegionProtocolGuid);
 152
 153   //
 154   // Install the protocol on a new handle.
 155   //
 156   Status = gBS->InstallMultipleProtocolInterfaces (
 157                   &mLegacyRegionHandle,
 158                   &gEfiLegacyRegionProtocolGuid, &mLegacyRegion,
 159                   NULL
 160                   );
 161   ASSERT_EFI_ERROR (Status);
 162
 163   return Status;
 164 }