/** @file
This file declares the SMM SMRAM Access abstraction protocol, which is used to control
the visibility of the SMRAM on the platform. The expectation is
that the north bridge or memory controller would publish this protocol.
For example, the Memory Controller Hub (MCH) has the hardware provision for this
type of control. Because of the protected, distinguished class of memory for IA-32
systems, the expectation is that this protocol would be supported only on IA-32 systems.
Copyright (c) 2007 - 2010, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available under
the terms and conditions of the BSD License that accompanies this distribution.
The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
@par Revision Reference:
This Protocol is defined in Framework of EFI SMM Core Interface Spec
Version 0.9.
**/
#ifndef _SMM_ACCESS_H_
#define _SMM_ACCESS_H_
#include <Guid/SmramMemoryReserve.h>
typedef struct _EFI_SMM_ACCESS_PROTOCOL EFI_SMM_ACCESS_PROTOCOL;
#define EFI_SMM_ACCESS_PROTOCOL_GUID \
{ \
0x3792095a, 0xe309, 0x4c1e, {0xaa, 0x01, 0x85, 0xf5, 0x65, 0x5a, 0x17, 0xf1 } \
}
//
// SMM Access specification Member Function
//
/**
Opens the SMRAM area to be accessible by a boot-service driver.
@param This The EFI_SMM_ACCESS_PROTOCOL instance.
@param DescriptorIndex Indicates that the driver wishes to open
the memory tagged by this index.
@retval EFI_SUCCESS The operation was successful.
@retval EFI_INVALID_PARAMETER The given DescriptorIndex is not supported.
@retval EFI_NOT_STARTED The SMM base service has not been initialized.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_SMM_OPEN)(
IN EFI_SMM_ACCESS_PROTOCOL *This,
UINTN DescriptorIndex
);
/**
Inhibits access to the SMRAM.
@param This The EFI_SMM_ACCESS_PROTOCOL instance.
@param DescriptorIndex Indicates that the driver wishes to close
the memory tagged by this index.
@retval EFI_SUCCESS The operation was successful.
@retval EFI_DEVICE_ERROR The given DescriptorIndex is not open.
@retval EFI_INVALID_PARAMETER The given DescriptorIndex is not supported.
@retval EFI_NOT_STARTED The SMM base service has not been initialized.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_SMM_CLOSE)(
IN EFI_SMM_ACCESS_PROTOCOL *This,
UINTN DescriptorIndex
);
/**
Inhibits access to the SMRAM.
@param This The EFI_SMM_ACCESS_PROTOCOL instance.
@param DescriptorIndex Indicates that the driver wishes to lock
the memory tagged by this index.
@retval EFI_SUCCESS The operation was successful.
@retval EFI_DEVICE_ERROR The given DescriptorIndex is not open.
@retval EFI_INVALID_PARAMETER The given DescriptorIndex is not supported.
@retval EFI_NOT_STARTED The SMM base service has not been initialized.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_SMM_LOCK)(
IN EFI_SMM_ACCESS_PROTOCOL *This,
UINTN DescriptorIndex
);
/**
Queries the memory controller for the possible regions that will support SMRAM.
@param This The EFI_SMM_ACCESS_PROTOCOL instance.
@param SmramMapSize A pointer to the size, in bytes, of the SmramMemoryMap buffer.
@param SmramMap A pointer to the buffer in which firmware places the current memory map.
@retval EFI_SUCCESS The chipset supported the given resource.
@retval EFI_BUFFER_TOO_SMALL The SmramMap parameter was too small.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_SMM_CAPABILITIES)(
IN EFI_SMM_ACCESS_PROTOCOL *This,
IN OUT UINTN *SmramMapSize,
IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap
);
/**
This protocol is used to control the visibility of the SMRAM on the platform.
**/
struct _EFI_SMM_ACCESS_PROTOCOL {
EFI_SMM_OPEN Open; ///< Opens the SMRAM.
EFI_SMM_CLOSE Close; ///< Closes the SMRAM.
EFI_SMM_LOCK Lock; ///< Locks the SMRAM.
EFI_SMM_CAPABILITIES GetCapabilities; ///< Gets information on possible SMRAM regions.
BOOLEAN LockState; ///< Indicates the current state of the SMRAM. Set to TRUE if any region is locked.
BOOLEAN OpenState; ///< Indicates the current state of the SMRAM. Set to TRUE if any region is open.
};
extern EFI_GUID gEfiSmmAccessProtocolGuid;
#endif