MdePkg/Include/Protocol/SmmCommunication.h

   1 /** @file
   2   EFI SMM Communication Protocol as defined in the PI 1.2 specification.
   3
   4   This protocol provides a means of communicating between drivers outside of SMM and SMI
   5   handlers inside of SMM.
   6
   7   Copyright (c) 2009, Intel Corporation
   8   All rights reserved. This program and the accompanying materials
   9   are licensed and made available under the terms and conditions of the BSD License
  10   which accompanies this distribution.  The full text of the license may be found at
  11   http://opensource.org/licenses/bsd-license.php
  12
  13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  14   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  15
  16 **/
  17
  18 #ifndef _SMM_COMMUNICATION_H_
  19 #define _SMM_COMMUNICATION_H_
  20
  21 #define EFI_SMM_COMMUNICATION_PROTOCOL_GUID \
  22   { \
  23     0xc68ed8e2, 0x9dc6, 0x4cbd, { 0x9d, 0x94, 0xdb, 0x65, 0xac, 0xc5, 0xc3, 0x32 } \
  24   }
  25
  26 ///
  27 /// To avoid confusion in interpreting frames, the communication buffer should always
  28 /// begin with EFI_SMM_COMMUNICATE_HEADER
  29 ///
  30 typedef struct {
  31   ///
  32   /// Allows for disambiguation of the message format.
  33   ///
  34   EFI_GUID  HeaderGuid;
  35   ///
  36   /// Describes the size of Data (in bytes) and does not include the size of the header.
  37   ///
  38   UINTN     MessageLength;
  39   ///
  40   /// Designates an array of bytes that is MessageLength in size.
  41   ///
  42   UINT8     Data[1];
  43 } EFI_SMM_COMMUNICATE_HEADER;
  44
  45 typedef struct _EFI_SMM_COMMUNICATION_PROTOCOL  EFI_SMM_COMMUNICATION_PROTOCOL;
  46
  47 /**
  48   Communicates with a registered handler.
  49
  50   This function provides a service to send and receive messages from a registered UEFI service.
  51
  52   @param[in] This                The EFI_SMM_COMMUNICATION_PROTOCOL instance.
  53   @param[in] CommBuffer          A pointer to the buffer to convey into SMRAM.
  54   @param[in] CommSize            The size of the data buffer being passed in.On exit, the size of data
  55                                  being returned. Zero if the handler does not wish to reply with any data.
  56
  57   @retval EFI_SUCCESS            The message was successfully posted.
  58   @retval EFI_INVALID_PARAMETER  The CommBuffer was NULL.
  59 **/
  60 typedef
  61 EFI_STATUS
  62 (EFIAPI *EFI_SMM_COMMUNICATE2)(
  63   IN CONST EFI_SMM_COMMUNICATION_PROTOCOL  *This,
  64   IN OUT VOID                              *CommBuffer,
  65   IN OUT UINTN                             *CommSize
  66   );
  67
  68 ///
  69 /// EFI SMM Communication Protocol provides runtime services for communicating
  70 /// between DXE drivers and a registered SMI handler.
  71 ///
  72 struct _EFI_SMM_COMMUNICATION_PROTOCOL {
  73   EFI_SMM_COMMUNICATE2  Communicate;
  74 };
  75
  76 extern EFI_GUID gEfiSmmCommunicationProtocolGuid;
  77
  78 #endif
  79