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Diffstat (limited to 'MdePkg/Include/Protocol/MmAccess.h')
-rw-r--r-- | MdePkg/Include/Protocol/MmAccess.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/MdePkg/Include/Protocol/MmAccess.h b/MdePkg/Include/Protocol/MmAccess.h new file mode 100644 index 0000000000..ad3ed7bb65 --- /dev/null +++ b/MdePkg/Include/Protocol/MmAccess.h @@ -0,0 +1,133 @@ +/** @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
+
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