9607962def
Note: * This only works before ExitBootServices * For OVMF, variables are only preserved on the disk if there is a hard disk connected which has a writeable FAT file system. The Ovmf/Library/EmuVariableFvbLib library will look for the gUefiOvmfPkgTokenSpaceGuid.PcdEmuVariableEvent PCD to be set to a non-zero value. If set, it is treated as an event handle, and each write to the EmuVariableFvb will cause the event to be signaled. In this change, the OVMF platform BDS library sets up this event, and sets the PCD so that after each write to the EMU Variable FVB, the non-volatile variables will be saved out to the file system. The end result is that NV variables that are written prior to the ExitBootServices call should be preserved by storing them on the disk. git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9318 6f19259b-4bc3-4df7-8a09-765794883524
84 lines
2.1 KiB
C
84 lines
2.1 KiB
C
/** @file
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Save Non-Volatile Variables to a file system.
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Copyright (c) 2009, Intel Corporation. <BR>
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All rights reserved. This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution. The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#include "NvVarsFileLib.h"
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#include <Library/DebugLib.h>
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#include <Library/NvVarsFileLib.h>
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EFI_HANDLE mNvVarsFileLibFsHandle = NULL;
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/**
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Attempts to connect the NvVarsFileLib to the specified file system.
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@param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
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@return The EFI_STATUS while attempting to connect the NvVarsFileLib
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to the file system instance.
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@retval EFI_SUCCESS - The given file system was connected successfully
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**/
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EFI_STATUS
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EFIAPI
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ConnectNvVarsToFileSystem (
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IN EFI_HANDLE FsHandle
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)
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{
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EFI_STATUS Status;
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//
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// We might fail to load the variable, since the file system initially
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// will not have the NvVars file.
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//
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LoadNvVarsFromFs (FsHandle);
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//
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// We must be able to save the variables successfully to the file system
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// to have connected successfully.
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//
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Status = SaveNvVarsToFs (FsHandle);
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if (!EFI_ERROR (Status)) {
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mNvVarsFileLibFsHandle = FsHandle;
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}
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return Status;
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}
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/**
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Update non-volatile variables stored on the file system.
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@return The EFI_STATUS while attempting to update the variable on
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the connected file system.
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@retval EFI_SUCCESS - The non-volatile variables were saved to the disk
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@retval EFI_NOT_STARTED - A file system has not been connected
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**/
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EFI_STATUS
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EFIAPI
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UpdateNvVarsOnFileSystem (
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)
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{
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if (mNvVarsFileLibFsHandle == NULL) {
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//
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// A file system had not been connected to the library.
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//
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return EFI_NOT_STARTED;
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} else {
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return SaveNvVarsToFs (mNvVarsFileLibFsHandle);
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}
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}
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