SmmAccess2Dxe.c File Reference

#include <Library/DebugLib.h>
#include <Library/PcdLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Protocol/SmmAccess2.h>
#include "SmramInternal.h"

Go to the source code of this file.

Functions
STATIC EFI_STATUS EFIAPI	SmmAccess2DxeOpen (IN EFI_SMM_ACCESS2_PROTOCOL *This)
STATIC EFI_STATUS EFIAPI	SmmAccess2DxeClose (IN EFI_SMM_ACCESS2_PROTOCOL *This)
STATIC EFI_STATUS EFIAPI	SmmAccess2DxeLock (IN EFI_SMM_ACCESS2_PROTOCOL *This)
STATIC EFI_STATUS EFIAPI	SmmAccess2DxeGetCapabilities (IN CONST EFI_SMM_ACCESS2_PROTOCOL *This, IN OUT UINTN *SmramMapSize, IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap)
EFI_STATUS EFIAPI	SmmAccess2DxeEntryPoint (IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)

Variables
STATIC EFI_SMM_ACCESS2_PROTOCOL	mAccess2

Detailed Description

A DXE_DRIVER providing SMRAM access by producing EFI_SMM_ACCESS2_PROTOCOL.

Q35 TSEG is expected to have been verified and set up by the SmmAccessPei driver.

Copyright (C) 2013, 2015, Red Hat, Inc.
Copyright (c) 2009 - 2024, Intel Corporation. All rights reserved.

SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file SmmAccess2Dxe.c.

Function Documentation

SmmAccess2DxeClose()

STATIC EFI_STATUS EFIAPI SmmAccess2DxeClose

(

IN EFI_SMM_ACCESS2_PROTOCOL *

This

)

Inhibits access to the SMRAM.

This function "closes" SMRAM so that it is not visible while outside of SMM. The function should return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM.

Parameters

[in]

This

The EFI_SMM_ACCESS2_PROTOCOL instance.

Return values

EFI_SUCCESS	The operation was successful.
EFI_UNSUPPORTED	The system does not support opening and closing of SMRAM.
EFI_DEVICE_ERROR	SMRAM cannot be closed.

Definition at line 65 of file SmmAccess2Dxe.c.

SmmAccess2DxeEntryPoint()

EFI_STATUS EFIAPI SmmAccess2DxeEntryPoint	(	IN EFI_HANDLE	ImageHandle,
		IN EFI_SYSTEM_TABLE *	SystemTable
	)

Definition at line 138 of file SmmAccess2Dxe.c.

SmmAccess2DxeGetCapabilities()

STATIC EFI_STATUS EFIAPI SmmAccess2DxeGetCapabilities	(	IN CONST EFI_SMM_ACCESS2_PROTOCOL *	This,
		IN OUT UINTN *	SmramMapSize,
		IN OUT EFI_SMRAM_DESCRIPTOR *	SmramMap
	)

Queries the memory controller for the possible regions that will support SMRAM.

Parameters

[in]	This	The EFI_SMM_ACCESS2_PROTOCOL instance.
[in,out]	SmramMapSize	A pointer to the size, in bytes, of the SmramMemoryMap buffer.
[in,out]	SmramMap	A pointer to the buffer in which firmware places the current memory map.

Return values

EFI_SUCCESS	The chipset supported the given resource.
EFI_BUFFER_TOO_SMALL	The SmramMap parameter was too small. The current buffer size needed to hold the memory map is returned in SmramMapSize.

Definition at line 111 of file SmmAccess2Dxe.c.

SmmAccess2DxeLock()

STATIC EFI_STATUS EFIAPI SmmAccess2DxeLock

(

IN EFI_SMM_ACCESS2_PROTOCOL *

This

)

Inhibits access to the SMRAM.

This function prohibits access to the SMRAM region. This function is usually implemented such that it is a write-once operation.

Parameters

[in]

This

The EFI_SMM_ACCESS2_PROTOCOL instance.

Return values

EFI_SUCCESS	The device was successfully locked.
EFI_UNSUPPORTED	The system does not support locking of SMRAM.

Definition at line 86 of file SmmAccess2Dxe.c.

SmmAccess2DxeOpen()

STATIC EFI_STATUS EFIAPI SmmAccess2DxeOpen

(

IN EFI_SMM_ACCESS2_PROTOCOL *

This

)

Opens the SMRAM area to be accessible by a boot-service driver.

This function "opens" SMRAM so that it is visible while not inside of SMM. The function should return EFI_UNSUPPORTED if the hardware does not support hiding of SMRAM. The function should return EFI_DEVICE_ERROR if the SMRAM configuration is locked.

Parameters

[in]

This

The EFI_SMM_ACCESS2_PROTOCOL instance.

Return values

EFI_SUCCESS	The operation was successful.
EFI_UNSUPPORTED	The system does not support opening and closing of SMRAM.
EFI_DEVICE_ERROR	SMRAM cannot be opened, perhaps because it is locked.

Definition at line 41 of file SmmAccess2Dxe.c.

Variable Documentation

mAccess2

STATIC EFI_SMM_ACCESS2_PROTOCOL mAccess2

Initial value:

= {
  &SmmAccess2DxeOpen,
  &SmmAccess2DxeClose,
  &SmmAccess2DxeLock,
  &SmmAccess2DxeGetCapabilities
}

Definition at line 126 of file SmmAccess2Dxe.c.