/** @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.
Copyright (c) 2009 - 2024, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent **/ #include #include #include #include #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 ( 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 ); }