/** @file | |
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.<BR> | |
Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR> | |
SPDX-License-Identifier: BSD-2-Clause-Patent | |
**/ | |
#include <Library/DebugLib.h> | |
#include <Library/PcdLib.h> | |
#include <Library/UefiBootServicesTableLib.h> | |
#include <Protocol/SmmAccess2.h> | |
#include "SmramInternal.h" | |
/** | |
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. | |
@param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance. | |
@retval EFI_SUCCESS The operation was successful. | |
@retval EFI_UNSUPPORTED The system does not support opening and closing of | |
SMRAM. | |
@retval EFI_DEVICE_ERROR SMRAM cannot be opened, perhaps because it is | |
locked. | |
**/ | |
STATIC | |
EFI_STATUS | |
EFIAPI | |
SmmAccess2DxeOpen ( | |
IN EFI_SMM_ACCESS2_PROTOCOL *This | |
) | |
{ | |
return SmramAccessOpen (&This->LockState, &This->OpenState); | |
} | |
/** | |
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. | |
@param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance. | |
@retval EFI_SUCCESS The operation was successful. | |
@retval EFI_UNSUPPORTED The system does not support opening and closing of | |
SMRAM. | |
@retval EFI_DEVICE_ERROR SMRAM cannot be closed. | |
**/ | |
STATIC | |
EFI_STATUS | |
EFIAPI | |
SmmAccess2DxeClose ( | |
IN EFI_SMM_ACCESS2_PROTOCOL *This | |
) | |
{ | |
return SmramAccessClose (&This->LockState, &This->OpenState); | |
} | |
/** | |
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. | |
@param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance. | |
@retval EFI_SUCCESS The device was successfully locked. | |
@retval EFI_UNSUPPORTED The system does not support locking of SMRAM. | |
**/ | |
STATIC | |
EFI_STATUS | |
EFIAPI | |
SmmAccess2DxeLock ( | |
IN EFI_SMM_ACCESS2_PROTOCOL *This | |
) | |
{ | |
return SmramAccessLock (&This->LockState, &This->OpenState); | |
} | |
/** | |
Queries the memory controller for the possible regions that will support | |
SMRAM. | |
@param[in] This The EFI_SMM_ACCESS2_PROTOCOL instance. | |
@param[in,out] SmramMapSize A pointer to the size, in bytes, of the | |
SmramMemoryMap buffer. | |
@param[in,out] 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. The | |
current buffer size needed to hold the memory | |
map is returned in SmramMapSize. | |
**/ | |
STATIC | |
EFI_STATUS | |
EFIAPI | |
SmmAccess2DxeGetCapabilities ( | |
IN CONST EFI_SMM_ACCESS2_PROTOCOL *This, | |
IN OUT UINTN *SmramMapSize, | |
IN OUT EFI_SMRAM_DESCRIPTOR *SmramMap | |
) | |
{ | |
return SmramAccessGetCapabilities ( | |
This->LockState, | |
This->OpenState, | |
SmramMapSize, | |
SmramMap | |
); | |
} | |
// | |
// LockState and OpenState will be filled in by the entry point. | |
// | |
STATIC EFI_SMM_ACCESS2_PROTOCOL mAccess2 = { | |
&SmmAccess2DxeOpen, | |
&SmmAccess2DxeClose, | |
&SmmAccess2DxeLock, | |
&SmmAccess2DxeGetCapabilities | |
}; | |
// | |
// Entry point of this driver. | |
// | |
EFI_STATUS | |
EFIAPI | |
SmmAccess2DxeEntryPoint ( | |
IN EFI_HANDLE ImageHandle, | |
IN EFI_SYSTEM_TABLE *SystemTable | |
) | |
{ | |
// | |
// This module should only be included if SMRAM support is required. | |
// | |
ASSERT (FeaturePcdGet (PcdSmmSmramRequire)); | |
InitQ35TsegMbytes (); | |
GetStates (&mAccess2.LockState, &mAccess2.OpenState); | |
// | |
// SmramAccessLock() depends on "mQ35SmramAtDefaultSmbase"; init the latter | |
// just before exposing the former via EFI_SMM_ACCESS2_PROTOCOL.Lock(). | |
// | |
InitQ35SmramAtDefaultSmbase (); | |
return gBS->InstallMultipleProtocolInterfaces ( | |
&ImageHandle, | |
&gEfiSmmAccess2ProtocolGuid, | |
&mAccess2, | |
NULL | |
); | |
} |