/** @file | |
EFI MM Access Protocol as defined in the PI 1.5 specification. | |
This protocol is used to control the visibility of the MMRAM on the platform. | |
It abstracts the location and characteristics of MMRAM. The expectation is | |
that the north bridge or memory controller would publish this protocol. | |
The principal functionality found in the memory controller includes the following: | |
- Exposing the MMRAM to all non-MM agents, or the "open" state | |
- Shrouding the MMRAM to all but the MM agents, or the "closed" state | |
- Preserving the system integrity, or "locking" the MMRAM, such that the settings cannot be | |
perturbed by either boot service or runtime agents | |
Copyright (c) 2017, 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 | |
which 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. | |
**/ | |
#ifndef _MM_ACCESS_H_ | |
#define _MM_ACCESS_H_ | |
#define EFI_MM_ACCESS_PROTOCOL_GUID \ | |
{ \ | |
0xc2702b74, 0x800c, 0x4131, {0x87, 0x46, 0x8f, 0xb5, 0xb8, 0x9c, 0xe4, 0xac } \ | |
} | |
typedef struct _EFI_MM_ACCESS_PROTOCOL EFI_MM_ACCESS_PROTOCOL; | |
/** | |
Opens the MMRAM area to be accessible by a boot-service driver. | |
This function "opens" MMRAM so that it is visible while not inside of MM. The function should | |
return EFI_UNSUPPORTED if the hardware does not support hiding of MMRAM. The function | |
should return EFI_DEVICE_ERROR if the MMRAM configuration is locked. | |
@param[in] This The EFI_MM_ACCESS_PROTOCOL instance. | |
@retval EFI_SUCCESS The operation was successful. | |
@retval EFI_UNSUPPORTED The system does not support opening and closing of MMRAM. | |
@retval EFI_DEVICE_ERROR MMRAM cannot be opened, perhaps because it is locked. | |
**/ | |
typedef | |
EFI_STATUS | |
(EFIAPI *EFI_MM_OPEN)( | |
IN EFI_MM_ACCESS_PROTOCOL *This | |
); | |
/** | |
Inhibits access to the MMRAM. | |
This function "closes" MMRAM so that it is not visible while outside of MM. The function should | |
return EFI_UNSUPPORTED if the hardware does not support hiding of MMRAM. | |
@param[in] This The EFI_MM_ACCESS_PROTOCOL instance. | |
@retval EFI_SUCCESS The operation was successful. | |
@retval EFI_UNSUPPORTED The system does not support opening and closing of MMRAM. | |
@retval EFI_DEVICE_ERROR MMRAM cannot be closed. | |
**/ | |
typedef | |
EFI_STATUS | |
(EFIAPI *EFI_MM_CLOSE)( | |
IN EFI_MM_ACCESS_PROTOCOL *This | |
); | |
/** | |
Inhibits access to the MMRAM. | |
This function prohibits access to the MMRAM region. This function is usually implemented such | |
that it is a write-once operation. | |
@param[in] This The EFI_MM_ACCESS_PROTOCOL instance. | |
@retval EFI_SUCCESS The device was successfully locked. | |
@retval EFI_UNSUPPORTED The system does not support locking of MMRAM. | |
**/ | |
typedef | |
EFI_STATUS | |
(EFIAPI *EFI_MM_LOCK)( | |
IN EFI_MM_ACCESS_PROTOCOL *This | |
); | |
/** | |
Queries the memory controller for the possible regions that will support MMRAM. | |
@param[in] This The EFI_MM_ACCESS_PROTOCOL instance. | |
@param[in,out] MmramMapSize A pointer to the size, in bytes, of the MmramMemoryMap buffer. | |
@param[in,out] MmramMap 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 MmramMap parameter was too small. The current buffer size | |
needed to hold the memory map is returned in MmramMapSize. | |
**/ | |
typedef | |
EFI_STATUS | |
(EFIAPI *EFI_MM_CAPABILITIES)( | |
IN CONST EFI_MM_ACCESS_PROTOCOL *This, | |
IN OUT UINTN *MmramMapSize, | |
IN OUT EFI_MMRAM_DESCRIPTOR *MmramMap | |
); | |
/// | |
/// EFI MM Access Protocol is used to control the visibility of the MMRAM on the platform. | |
/// It abstracts the location and characteristics of MMRAM. The platform should report all | |
/// MMRAM via EFI_MM_ACCESS_PROTOCOL. The expectation is that the north bridge or memory | |
/// controller would publish this protocol. | |
/// | |
struct _EFI_MM_ACCESS_PROTOCOL { | |
EFI_MM_OPEN Open; | |
EFI_MM_CLOSE Close; | |
EFI_MM_LOCK Lock; | |
EFI_MM_CAPABILITIES GetCapabilities; | |
/// | |
/// Indicates the current state of the MMRAM. Set to TRUE if MMRAM is locked. | |
/// | |
BOOLEAN LockState; | |
/// | |
/// Indicates the current state of the MMRAM. Set to TRUE if MMRAM is open. | |
/// | |
BOOLEAN OpenState; | |
}; | |
extern EFI_GUID gEfiMmAccessProtocolGuid; | |
#endif | |