Intel Extensible Firmware Interface - Manual (Page 383)

Protocols — Bootable Image Support
Version 1.10 12/01/02 11-23
#define EFI_FILE_RESERVED 0x0000000000000008
#define EFI_FILE_DIRECTORY 0x0000000000000010
#define EFI_FILE_ARCHIVE 0x0000000000000020
#define EFI_FILE_VALID_ATTR 0x0000000000000037
Description
The Open() function opens the file or directory referred to by FileName relative to the location
of This and returns a NewHandle . The FileName may include the following path modifiers:
“\” If the filename starts with a “\” the relative location is the root directory
that
This residues on; otherwise “\” separates name components. Each
name component is opened in turn, and the handle to the last file opened
is returned.
“ . ” Opens the current location.
“ .. ” Opens the parent directory for the current location. If the location is the
root directory the request will return an error, as there is no parent
directory for the root directory.
If EFI_FILE_MODE_CREATE is set, then the file is created in the directory. If the final location
of FileName does not refer to a directory, then the operation fails. If the file does not exist in the
directory, then a new file is created. If the file already exists in the directory, then the existing file
is opened.
If the medium of the device changes, all accesses (including the File handle) will result in
EFI_MEDIA_CHANGED . To access the new medium, the volume must be reopened.
Status Codes Returned
EFI_SUCCESS The file was opened.
EFI_NOT_FOUND The specified file could not be found on the device.
EFI_NO_MEDIA The device has no medium.
EFI_MEDIA_CHANGED The device has a different medium in it or the medium is no
longer supported.
EFI_DEVICE_ERROR The device reported an error.
EFI_VOLUME_CORRUPTED The file system structures are corrupted.
EFI_WRITE_PROTECTED An attempt was made to create a file, or open a file for write
when the media is write protected.
EFI_ACCESS_DENIED The service denied access to the file.
EFI_OUT_OF_RESOURCES Not enough resources were available to open the file.
EFI_VOLUME_FULL The volume is full.