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      1 /** @file
      2   This file declares the SMM SMRAM Access abstraction protocol, which is used to control
      3   the visibility of the SMRAM on the platform. The expectation is
      4   that the north bridge or memory controller would publish this protocol.
      5   For example, the Memory Controller Hub (MCH) has the hardware provision for this
      6   type of control. Because of the protected, distinguished class of memory for IA-32
      7   systems, the expectation is that this protocol would be supported only on IA-32 systems.
      8 
      9 Copyright (c) 2007 - 2010, Intel Corporation. All rights reserved.<BR>
     10 This program and the accompanying materials are licensed and made available under
     11 the terms and conditions of the BSD License that accompanies this distribution.
     12 The full text of the license may be found at
     13 http://opensource.org/licenses/bsd-license.php.
     14 
     15 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
     16 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     17 
     18   @par Revision Reference:
     19   This Protocol is defined in Framework of EFI SMM Core Interface Spec
     20   Version 0.9.
     21 **/
     22 
     23 #ifndef _SMM_ACCESS_H_
     24 #define _SMM_ACCESS_H_
     25 
     26 #include <Guid/SmramMemoryReserve.h>
     27 
     28 typedef struct _EFI_SMM_ACCESS_PROTOCOL  EFI_SMM_ACCESS_PROTOCOL;
     29 
     30 #define EFI_SMM_ACCESS_PROTOCOL_GUID \
     31   { \
     32     0x3792095a, 0xe309, 0x4c1e, {0xaa, 0x01, 0x85, 0xf5, 0x65, 0x5a, 0x17, 0xf1 } \
     33   }
     34 
     35 //
     36 // SMM Access specification Member Function
     37 //
     38 /**
     39   Opens the SMRAM area to be accessible by a boot-service driver.
     40 
     41   @param  This                  The EFI_SMM_ACCESS_PROTOCOL instance.
     42   @param  DescriptorIndex       Indicates that the driver wishes to open
     43                                 the memory tagged by this index.
     44 
     45   @retval EFI_SUCCESS           The operation was successful.
     46   @retval EFI_INVALID_PARAMETER The given DescriptorIndex is not supported.
     47   @retval EFI_NOT_STARTED       The SMM base service has not been initialized.
     48 
     49 **/
     50 typedef
     51 EFI_STATUS
     52 (EFIAPI *EFI_SMM_OPEN)(
     53   IN EFI_SMM_ACCESS_PROTOCOL         *This,
     54   UINTN                              DescriptorIndex
     55   );
     56 
     57 /**
     58   Inhibits access to the SMRAM.
     59 
     60   @param  This                  The EFI_SMM_ACCESS_PROTOCOL instance.
     61   @param  DescriptorIndex       Indicates that the driver wishes to close
     62                                 the memory tagged by this index.
     63 
     64   @retval EFI_SUCCESS           The operation was successful.
     65   @retval EFI_DEVICE_ERROR      The given DescriptorIndex is not open.
     66   @retval EFI_INVALID_PARAMETER The given DescriptorIndex is not supported.
     67   @retval EFI_NOT_STARTED       The SMM base service has not been initialized.
     68 
     69 **/
     70 typedef
     71 EFI_STATUS
     72 (EFIAPI *EFI_SMM_CLOSE)(
     73   IN EFI_SMM_ACCESS_PROTOCOL          *This,
     74   UINTN                               DescriptorIndex
     75   );
     76 
     77 /**
     78   Inhibits access to the SMRAM.
     79 
     80   @param  This                  The EFI_SMM_ACCESS_PROTOCOL instance.
     81   @param  DescriptorIndex       Indicates that the driver wishes to lock
     82                                 the memory tagged by this index.
     83 
     84   @retval EFI_SUCCESS           The operation was successful.
     85   @retval EFI_DEVICE_ERROR      The given DescriptorIndex is not open.
     86   @retval EFI_INVALID_PARAMETER The given DescriptorIndex is not supported.
     87   @retval EFI_NOT_STARTED       The SMM base service has not been initialized.
     88 
     89 **/
     90 typedef
     91 EFI_STATUS
     92 (EFIAPI *EFI_SMM_LOCK)(
     93   IN EFI_SMM_ACCESS_PROTOCOL         *This,
     94   UINTN                              DescriptorIndex
     95   );
     96 
     97 /**
     98   Queries the memory controller for the possible regions that will support SMRAM.
     99 
    100   @param  This                  The EFI_SMM_ACCESS_PROTOCOL instance.
    101   @param  SmramMapSize          A pointer to the size, in bytes, of the SmramMemoryMap buffer.
    102   @param  SmramMap              A pointer to the buffer in which firmware places the current memory map.
    103 
    104   @retval EFI_SUCCESS           The chipset supported the given resource.
    105   @retval EFI_BUFFER_TOO_SMALL  The SmramMap parameter was too small.
    106 
    107 **/
    108 typedef
    109 EFI_STATUS
    110 (EFIAPI *EFI_SMM_CAPABILITIES)(
    111   IN EFI_SMM_ACCESS_PROTOCOL             *This,
    112   IN OUT UINTN                           *SmramMapSize,
    113   IN OUT EFI_SMRAM_DESCRIPTOR            *SmramMap
    114   );
    115 
    116 /**
    117   This protocol is used to control the visibility of the SMRAM on the platform.
    118 **/
    119 struct _EFI_SMM_ACCESS_PROTOCOL {
    120   EFI_SMM_OPEN          Open;             ///< Opens the SMRAM.
    121   EFI_SMM_CLOSE         Close;            ///< Closes the SMRAM.
    122   EFI_SMM_LOCK          Lock;             ///< Locks the SMRAM.
    123   EFI_SMM_CAPABILITIES  GetCapabilities;  ///< Gets information on possible SMRAM regions.
    124   BOOLEAN               LockState;        ///< Indicates the current state of the SMRAM. Set to TRUE if any region is locked.
    125   BOOLEAN               OpenState;        ///< Indicates the current state of the SMRAM. Set to TRUE if any region is open.
    126 };
    127 
    128 extern EFI_GUID gEfiSmmAccessProtocolGuid;
    129 
    130 #endif
    131