4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync File System Access for NvVarsFileLib
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Copyright (c) 2004 - 2011, Intel Corporation. All rights reserved.<BR>
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync This program and the accompanying materials
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync are licensed and made available under the terms and conditions of the BSD License
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync which accompanies this distribution. The full text of the license may be found at
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Open the NvVars file for reading or writing
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] ReadingFile - TRUE: open the file for reading. FALSE: writing
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[out] NvVarsFile - If EFI_SUCCESS is returned, then this is updated
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync with the opened NvVars file.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @return EFI_SUCCESS if the file was opened
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Get the FileSystem protocol on that handle
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Get the volume (the root directory)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Attempt to open the NvVars file in the root directory
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Open the NvVars file for reading or writing
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] File - The file to inspect
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[out] Exists - Returns whether the file exists
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[out] Size - Returns the size of the file
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync (0 if the file does not exist)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) != 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Open the NvVars file for reading or writing
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] File - The file to inspect
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[out] Exists - Returns whether the file exists
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[out] Size - Returns the size of the file
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync (0 if the file does not exist)
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Retrieve the FileInfo structure
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // If the path is a directory, then return an error
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) != 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // If the file size is already 0, then it is empty, so
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // we can return success.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Set the file size to 0.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Reads a file to a newly allocated buffer
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] File - The file to read
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] ReadSize - The size of data to read from the file
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @return Pointer to buffer allocated to hold the file
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync contents. NULL if an error occured.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if (EFI_ERROR (Status) || (ActualReadSize != ReadSize)) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Reads the contents of the NvVars file on the file system
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @return EFI_STATUS based on the success or failure of the file read
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync DEBUG ((EFI_D_INFO, "FsAccess.c: Could not open NV Variables file on this file system\n"));
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync NvVarsFileReadCheckup (File, &FileExists, &FileSize);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync FileContents = FileHandleReadToNewBuffer (File, FileSize);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync "FsAccess.c: Read %d bytes from NV Variables file\n",
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Status = SerializeVariablesSetSerializedVariables (SerializedVariables);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Loads the non-volatile variables from the NvVars file on the
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync given file system.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @return EFI_STATUS based on the success or failure of load operation
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync DEBUG ((EFI_D_INFO, "FsAccess.c: LoadNvVarsFromFs\n"));
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // We write a variable to indicate we've already loaded the
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // variable data. If it is found, we skip the loading.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // This is relevent if the non-volatile variable have been
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // able to survive a reboot operation. In that case, we don't
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // want to re-load the file as it would overwrite newer changes
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // made to the variables.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync DEBUG ((EFI_D_INFO, "NV Variables were already loaded\n"));
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Attempt to restore the variables from the NvVars file.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync DEBUG ((EFI_D_INFO, "Error while restoring NV variable data\n"));
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Write a variable to indicate we've already loaded the
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // variable data. If it is found, we skip the loading on
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // subsequent attempts.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync "FsAccess.c: Read NV Variables file (size=%d)\n",
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Only save non-volatile variables
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync if ((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) {
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Saves the non-volatile variables into the NvVars file on the
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync given file system.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync @return EFI_STATUS based on the success or failure of load operation
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Status = SerializeVariablesNewInstance (&SerializedVariables);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Status = SerializeVariablesIterateSystemVariables (
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync SerializeVariablesFreeInstance (SerializedVariables);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Open the NvVars file for writing.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync DEBUG ((EFI_D_INFO, "FsAccess.c: Unable to open file to saved NV Variables\n"));
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync // Empty the starting file contents.
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync Status = FileHandleWrite (File, &WriteSize, VariableData);
4fd606d1f5abe38e1f42c38de1d2e895166bd0f4vboxsync DEBUG ((EFI_D_INFO, "Saved NV Variables to NvVars file\n"));