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, Intel Corporation
  11 All rights reserved. This program and the accompanying materials
  12 are licensed and made available under the terms and conditions of the BSD License
  13 which accompanies this distribution.  The full text of the license may be found at
  14 http://opensource.org/licenses/bsd-license.php
  15
  16 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  17 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  18
  19 **/
  20
  21 #include <PiDxe.h>
  22 #include <Protocol/LegacyRegion.h>
  23 #include <Library/DebugLib.h>
  24 #include <Library/UefiBootServicesTableLib.h>
  25
  26 /**
  27   Sets hardware to decode or not decode a region.
  28
  29   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
  30   @param  Start                 Start of region to decode.
  31   @param  Length                Size in bytes of the region.
  32   @param  On                    Decode/nondecode flag.
  33
  34   @retval EFI_SUCCESS           Decode range successfully changed.
  35
  36 **/
  37 EFI_STATUS
  38 EFIAPI
  39 LegacyRegionDecode (
  40   IN EFI_LEGACY_REGION_PROTOCOL  *This,
  41   IN UINT32                      Start,
  42   IN UINT32                      Length,
  43   IN BOOLEAN                     *On
  44   )
  45 {
  46   return EFI_SUCCESS;
  47 }
  48
  49 /**
  50   Sets a region to read only.
  51
  52   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
  53   @param  Start                 Start of region to lock.
  54   @param  Length                Size in bytes of the region.
  55   @param  Granularity           Lock attribute affects this granularity in bytes.
  56
  57   @retval EFI_SUCCESS           The region was made read only.
  58
  59 **/
  60 EFI_STATUS
  61 EFIAPI
  62 LegacyRegionLock (
  63   IN  EFI_LEGACY_REGION_PROTOCOL  *This,
  64   IN  UINT32                      Start,
  65   IN  UINT32                      Length,
  66   OUT UINT32                      *Granularity OPTIONAL
  67   )
  68 {
  69   return EFI_SUCCESS;
  70 }
  71
  72 /**
  73   Sets a region to read only and ensures that flash is locked from being
  74   inadvertently modified.
  75
  76   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
  77   @param  Start                 Start of region to lock.
  78   @param  Length                Size in bytes of the region.
  79   @param  Granularity           Lock attribute affects this granularity in bytes.
  80
  81   @retval EFI_SUCCESS           The region was made read only and flash is locked.
  82
  83 **/
  84 EFI_STATUS
  85 EFIAPI
  86 LegacyRegionBootLock (
  87   IN  EFI_LEGACY_REGION_PROTOCOL  *This,
  88   IN  UINT32                      Start,
  89   IN  UINT32                      Length,
  90   OUT UINT32                      *Granularity OPTIONAL
  91   )
  92 {
  93   return EFI_SUCCESS;
  94 }
  95
  96 /**
  97   Sets a region to read-write.
  98
  99   @param  This                  Indicates the EFI_LEGACY_REGION_PROTOCOL instance
 100   @param  Start                 Start of region to lock.
 101   @param  Length                Size in bytes of the region.
 102   @param  Granularity           Lock attribute affects this granularity in bytes.
 103
 104   @retval EFI_SUCCESS           The region was successfully made read-write.
 105
 106 **/
 107 EFI_STATUS
 108 EFIAPI
 109 LegacyRegionUnlock (
 110   IN  EFI_LEGACY_REGION_PROTOCOL  *This,
 111   IN  UINT32                      Start,
 112   IN  UINT32                      Length,
 113   OUT UINT32                      *Granularity OPTIONAL
 114   )
 115 {
 116   return EFI_SUCCESS;
 117 }
 118
 119 //
 120 // Module global for the handle the Legacy Region Protocol is installed
 121 //
 122 EFI_HANDLE                  mLegacyRegionHandle = NULL;
 123
 124 //
 125 // Module global for the Legacy Region Protocol instance that is installed onto
 126 // mLegacyRegionHandle
 127 //
 128 EFI_LEGACY_REGION_PROTOCOL  mLegacyRegion = {
 129   LegacyRegionDecode,
 130   LegacyRegionLock,
 131   LegacyRegionBootLock,
 132   LegacyRegionUnlock
 133 };
 134
 135 /**
 136   The user Entry Point for module LegacyRegionDxe.  The user code starts with this function.
 137
 138   @param[in] ImageHandle    The firmware allocated handle for the EFI image.
 139   @param[in] SystemTable    A pointer to the EFI System Table.
 140
 141   @retval EFI_SUCCESS       The entry point is executed successfully.
 142   @retval other             Some error occurs when executing this entry point.
 143
 144 **/
 145 EFI_STATUS
 146 EFIAPI
 147 LegacyRegionInstall (
 148   IN EFI_HANDLE        ImageHandle,
 149   IN EFI_SYSTEM_TABLE  *SystemTable
 150   )
 151 {
 152   EFI_STATUS  Status;
 153
 154   //
 155   // Make sure the Legacy Region Protocol is not already installed in the system
 156   //
 157   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiLegacyRegionProtocolGuid);
 158
 159   //
 160   // Install the protocol on a new handle.
 161   //
 162   Status = gBS->InstallMultipleProtocolInterfaces (
 163                   &mLegacyRegionHandle,
 164                   &gEfiLegacyRegionProtocolGuid, &mLegacyRegion,
 165                   NULL
 166                   );
 167   ASSERT_EFI_ERROR (Status);
 168
 169   return Status;
 170 }