EdkCompatibilityPkg/Compatibility/SmmAccess2OnSmmAccessThunk/SmmAccess2OnSmmAccessThunk.c

   1 /** @file
   2   SMM Access2 Protocol on SMM Access Protocol Thunk driver.
   3
   4   Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include "SmmAccess2OnSmmAccessThunk.h"
  16
  17 EFI_SMM_ACCESS2_PROTOCOL gSmmAccess2 = {
  18   SmmAccess2Open,
  19   SmmAccess2Close,
  20   SmmAccess2Lock,
  21   SmmAccess2GetCapabilities,
  22   FALSE,
  23   FALSE
  24 };
  25
  26 EFI_SMM_ACCESS_PROTOCOL  *mSmmAccess;
  27 UINTN                     mSmramRegionNumber;
  28
  29 /**
  30   Opens the SMRAM area to be accessible by a boot-service driver.
  31
  32   This function "opens" SMRAM so that it is visible while not inside of SMM. The function should
  33   return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM. The function
  34   should return EFI_DEVICE_ERROR if the SMRAM configuration is locked.
  35
  36   @param[in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
  37
  38   @retval EFI_SUCCESS       The operation was successful.
  39   @retval EFI_UNSUPPORTED   The system does not support opening and closing of SMRAM.
  40   @retval EFI_DEVICE_ERROR  SMRAM cannot be opened, perhaps because it is locked.
  41 **/
  42 EFI_STATUS
  43 EFIAPI
  44 SmmAccess2Open (
  45   IN EFI_SMM_ACCESS2_PROTOCOL  *This
  46   )
  47 {
  48   EFI_STATUS Status;
  49   UINTN      DescriptorIndex;
  50
  51   ///
  52   /// Open all SMRAM regions via SMM Access Protocol
  53   ///
  54
  55   Status = EFI_SUCCESS;
  56   for (DescriptorIndex = 0; DescriptorIndex < mSmramRegionNumber && !EFI_ERROR (Status); DescriptorIndex++) {
  57     Status = mSmmAccess->Open (mSmmAccess, DescriptorIndex);
  58   }
  59   if (!EFI_ERROR (Status)) {
  60     gSmmAccess2.OpenState = TRUE;
  61   }
  62   return Status;
  63 }
  64
  65 /**
  66   Inhibits access to the SMRAM.
  67
  68   This function "closes" SMRAM so that it is not visible while outside of SMM. The function should
  69   return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM.
  70
  71   @param [in] This           The EFI_SMM_ACCESS2_PROTOCOL instance.
  72
  73   @retval EFI_SUCCESS       The operation was successful.
  74   @retval EFI_UNSUPPORTED   The system does not support opening and closing of SMRAM.
  75   @retval EFI_DEVICE_ERROR  SMRAM cannot be closed.
  76 **/
  77 EFI_STATUS
  78 EFIAPI
  79 SmmAccess2Close (
  80   IN EFI_SMM_ACCESS2_PROTOCOL  *This
  81   )
  82 {
  83   EFI_STATUS Status;
  84   UINTN      DescriptorIndex;
  85
  86   ///
  87   /// Close all SMRAM regions via SMM Access Protocol
  88   ///
  89
  90   Status = EFI_SUCCESS;
  91   for (DescriptorIndex = 0; DescriptorIndex < mSmramRegionNumber && !EFI_ERROR (Status); DescriptorIndex++) {
  92     Status = mSmmAccess->Close (mSmmAccess, DescriptorIndex);
  93   }
  94   if (!EFI_ERROR (Status)) {
  95     gSmmAccess2.OpenState = FALSE;
  96   }
  97   return Status;
  98 }
  99
 100 /**
 101   Inhibits access to the SMRAM.
 102
 103   This function prohibits access to the SMRAM region.  This function is usually implemented such
 104   that it is a write-once operation.
 105
 106   @param[in] This          The EFI_SMM_ACCESS2_PROTOCOL instance.
 107
 108   @retval EFI_SUCCESS      The device was successfully locked.
 109   @retval EFI_UNSUPPORTED  The system does not support locking of SMRAM.
 110 **/
 111 EFI_STATUS
 112 EFIAPI
 113 SmmAccess2Lock (
 114   IN EFI_SMM_ACCESS2_PROTOCOL  *This
 115   )
 116 {
 117   EFI_STATUS Status;
 118   UINTN      DescriptorIndex;
 119
 120   ///
 121   /// Lock all SMRAM regions via SMM Access Protocol
 122   ///
 123
 124   Status = EFI_SUCCESS;
 125   for (DescriptorIndex = 0; DescriptorIndex < mSmramRegionNumber && !EFI_ERROR (Status); DescriptorIndex++) {
 126     Status = mSmmAccess->Lock (mSmmAccess, DescriptorIndex);
 127   }
 128   if (!EFI_ERROR (Status)) {
 129     gSmmAccess2.LockState = TRUE;
 130   }
 131   return Status;
 132 }
 133
 134 /**
 135   Queries the memory controller for the possible regions that will support SMRAM.
 136
 137   @param[in]     This           The EFI_SMM_ACCESS2_PROTOCOL instance.
 138   @param[in, out] SmramMapSize   A pointer to the size, in bytes, of the SmramMemoryMap buffer.
 139   @param[in, out] SmramMap       A pointer to the buffer in which firmware places the current memory map.
 140
 141   @retval EFI_SUCCESS           The chipset supported the given resource.
 142   @retval EFI_BUFFER_TOO_SMALL  The SmramMap parameter was too small.  The current buffer size
 143                                 needed to hold the memory map is returned in SmramMapSize.
 144 **/
 145 EFI_STATUS
 146 EFIAPI
 147 SmmAccess2GetCapabilities (
 148   IN CONST EFI_SMM_ACCESS2_PROTOCOL  *This,
 149   IN OUT UINTN                       *SmramMapSize,
 150   IN OUT EFI_SMRAM_DESCRIPTOR        *SmramMap
 151   )
 152 {
 153   return mSmmAccess->GetCapabilities (mSmmAccess, SmramMapSize, SmramMap);
 154 }
 155
 156 /**
 157   Entry Point for SMM Access2 On SMM Access Thunk driver.
 158
 159   @param[in] ImageHandle  Image handle of this driver.
 160   @param[in] SystemTable  A Pointer to the EFI System Table.
 161
 162   @retval EFI_SUCCESS  The entry point is executed successfully.
 163   @retval other        Some error occurred when executing this entry point.
 164 **/
 165 EFI_STATUS
 166 EFIAPI
 167 SmmAccess2ThunkMain (
 168   IN EFI_HANDLE        ImageHandle,
 169   IN EFI_SYSTEM_TABLE  *SystemTable
 170   )
 171 {
 172   EFI_STATUS            Status;
 173   UINTN                 SmramMapSize;
 174
 175   ///
 176   /// Locate SMM Access Protocol
 177   ///
 178   Status = gBS->LocateProtocol (&gEfiSmmAccessProtocolGuid, NULL, (VOID **)&mSmmAccess);
 179   ASSERT_EFI_ERROR (Status);
 180
 181   ///
 182   /// Calculate number of SMRAM regions
 183   ///
 184   SmramMapSize = 0;
 185   Status = mSmmAccess->GetCapabilities (mSmmAccess, &SmramMapSize, NULL);
 186   ASSERT (Status == EFI_BUFFER_TOO_SMALL);
 187
 188   mSmramRegionNumber =  SmramMapSize/sizeof (EFI_SMRAM_DESCRIPTOR);
 189   ASSERT (mSmramRegionNumber > 0);
 190
 191   ///
 192   /// Assume all SMRAM regions have consistent OPEN and LOCK states
 193   ///
 194   gSmmAccess2.OpenState = mSmmAccess->OpenState;
 195   gSmmAccess2.LockState = mSmmAccess->LockState;
 196
 197   ///
 198   /// Publish PI SMM Access2 Protocol
 199   ///
 200   Status = gBS->InstallProtocolInterface (
 201                   &ImageHandle,
 202                   &gEfiSmmAccess2ProtocolGuid,
 203                   EFI_NATIVE_INTERFACE,
 204                   &gSmmAccess2
 205                   );
 206   return Status;
 207 }
 208