CloverBootloader/OvmfPkg/Library/NvVarsFileLib/NvVarsFileLib.c

80 lines
1.9 KiB
C

/** @file
Save Non-Volatile Variables to a file system.
Copyright (c) 2009, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "NvVarsFileLib.h"
#include <Library/DebugLib.h>
#include <Library/NvVarsFileLib.h>
EFI_HANDLE mNvVarsFileLibFsHandle = NULL;
/**
Attempts to connect the NvVarsFileLib to the specified file system.
@param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
@return The EFI_STATUS while attempting to connect the NvVarsFileLib
to the file system instance.
@retval EFI_SUCCESS - The given file system was connected successfully
**/
EFI_STATUS
EFIAPI
ConnectNvVarsToFileSystem (
IN EFI_HANDLE FsHandle
)
{
EFI_STATUS Status;
if (FeaturePcdGet (PcdSecureBootSupported) ||
FeaturePcdGet (PcdBootRestrictToFirmware))
{
return EFI_UNSUPPORTED;
}
//
// We might fail to load the variable, since the file system initially
// will not have the NvVars file.
//
LoadNvVarsFromFs (FsHandle);
//
// We must be able to save the variables successfully to the file system
// to have connected successfully.
//
Status = SaveNvVarsToFs (FsHandle);
if (!EFI_ERROR (Status)) {
mNvVarsFileLibFsHandle = FsHandle;
}
return Status;
}
/**
Update non-volatile variables stored on the file system.
@return The EFI_STATUS while attempting to update the variable on
the connected file system.
@retval EFI_SUCCESS - The non-volatile variables were saved to the disk
@retval EFI_NOT_STARTED - A file system has not been connected
**/
EFI_STATUS
EFIAPI
UpdateNvVarsOnFileSystem (
)
{
if (mNvVarsFileLibFsHandle == NULL) {
//
// A file system had not been connected to the library.
//
return EFI_NOT_STARTED;
} else {
return SaveNvVarsToFs (mNvVarsFileLibFsHandle);
}
}