MdePkg/Include/Protocol/SimpleFileSystem.h

   1 /** @file
   2   SimpleFileSystem protocol as defined in the UEFI 2.0 specification.
   3
   4   The SimpleFileSystem protocol is the programmatic access to the FAT (12,16,32)
   5   file system specified in UEFI 2.0. It can also be used to abstract a file
   6   system other than FAT.
   7
   8   UEFI 2.0 can boot from any valid EFI image contained in a SimpleFileSystem.
   9
  10 Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
  11 SPDX-License-Identifier: BSD-2-Clause-Patent
  12
  13 **/
  14
  15 #ifndef __SIMPLE_FILE_SYSTEM_H__
  16 #define __SIMPLE_FILE_SYSTEM_H__
  17
  18 #define EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID \
  19   { \
  20     0x964e5b22, 0x6459, 0x11d2, {0x8e, 0x39, 0x0, 0xa0, 0xc9, 0x69, 0x72, 0x3b } \
  21   }
  22
  23 typedef struct _EFI_SIMPLE_FILE_SYSTEM_PROTOCOL EFI_SIMPLE_FILE_SYSTEM_PROTOCOL;
  24
  25 typedef struct _EFI_FILE_PROTOCOL EFI_FILE_PROTOCOL;
  26 typedef struct _EFI_FILE_PROTOCOL *EFI_FILE_HANDLE;
  27
  28 ///
  29 /// Protocol GUID name defined in EFI1.1.
  30 ///
  31 #define SIMPLE_FILE_SYSTEM_PROTOCOL  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID
  32
  33 ///
  34 /// Protocol name defined in EFI1.1.
  35 ///
  36 typedef EFI_SIMPLE_FILE_SYSTEM_PROTOCOL EFI_FILE_IO_INTERFACE;
  37 typedef EFI_FILE_PROTOCOL               EFI_FILE;
  38
  39 /**
  40   Open the root directory on a volume.
  41
  42   @param  This A pointer to the volume to open the root directory.
  43   @param  Root A pointer to the location to return the opened file handle for the
  44                root directory.
  45
  46   @retval EFI_SUCCESS          The device was opened.
  47   @retval EFI_UNSUPPORTED      This volume does not support the requested file system type.
  48   @retval EFI_NO_MEDIA         The device has no medium.
  49   @retval EFI_DEVICE_ERROR     The device reported an error.
  50   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
  51   @retval EFI_ACCESS_DENIED    The service denied access to the file.
  52   @retval EFI_OUT_OF_RESOURCES The volume was not opened due to lack of resources.
  53   @retval EFI_MEDIA_CHANGED    The device has a different medium in it or the medium is no
  54                                longer supported. Any existing file handles for this volume are
  55                                no longer valid. To access the files on the new medium, the
  56                                volume must be reopened with OpenVolume().
  57
  58 **/
  59 typedef
  60 EFI_STATUS
  61 (EFIAPI *EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_OPEN_VOLUME)(
  62   IN EFI_SIMPLE_FILE_SYSTEM_PROTOCOL    *This,
  63   OUT EFI_FILE_PROTOCOL                 **Root
  64   );
  65
  66 #define EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION  0x00010000
  67
  68 ///
  69 /// Revision defined in EFI1.1
  70 ///
  71 #define EFI_FILE_IO_INTERFACE_REVISION  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION
  72
  73 struct _EFI_SIMPLE_FILE_SYSTEM_PROTOCOL {
  74   ///
  75   /// The version of the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL. The version
  76   /// specified by this specification is 0x00010000. All future revisions
  77   /// must be backwards compatible.
  78   ///
  79   UINT64                                         Revision;
  80   EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_OPEN_VOLUME    OpenVolume;
  81 };
  82
  83 /**
  84   Opens a new file relative to the source file's location.
  85
  86   @param  This       A pointer to the EFI_FILE_PROTOCOL instance that is the file
  87                      handle to the source location. This would typically be an open
  88                      handle to a directory.
  89   @param  NewHandle  A pointer to the location to return the opened handle for the new
  90                      file.
  91   @param  FileName   The Null-terminated string of the name of the file to be opened.
  92                      The file name may contain the following path modifiers: "\", ".",
  93                      and "..".
  94   @param  OpenMode   The mode to open the file. The only valid combinations that the
  95                      file may be opened with are: Read, Read/Write, or Create/Read/Write.
  96   @param  Attributes Only valid for EFI_FILE_MODE_CREATE, in which case these are the
  97                      attribute bits for the newly created file.
  98
  99   @retval EFI_SUCCESS          The file was opened.
 100   @retval EFI_NOT_FOUND        The specified file could not be found on the device.
 101   @retval EFI_NO_MEDIA         The device has no medium.
 102   @retval EFI_MEDIA_CHANGED    The device has a different medium in it or the medium is no
 103                                longer supported.
 104   @retval EFI_DEVICE_ERROR     The device reported an error.
 105   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 106   @retval EFI_WRITE_PROTECTED  An attempt was made to create a file, or open a file for write
 107                                when the media is write-protected.
 108   @retval EFI_ACCESS_DENIED    The service denied access to the file.
 109   @retval EFI_OUT_OF_RESOURCES Not enough resources were available to open the file.
 110   @retval EFI_VOLUME_FULL      The volume is full.
 111
 112 **/
 113 typedef
 114 EFI_STATUS
 115 (EFIAPI *EFI_FILE_OPEN)(
 116   IN EFI_FILE_PROTOCOL        *This,
 117   OUT EFI_FILE_PROTOCOL       **NewHandle,
 118   IN CHAR16                   *FileName,
 119   IN UINT64                   OpenMode,
 120   IN UINT64                   Attributes
 121   );
 122
 123 //
 124 // Open modes
 125 //
 126 #define EFI_FILE_MODE_READ    0x0000000000000001ULL
 127 #define EFI_FILE_MODE_WRITE   0x0000000000000002ULL
 128 #define EFI_FILE_MODE_CREATE  0x8000000000000000ULL
 129
 130 //
 131 // File attributes
 132 //
 133 #define EFI_FILE_READ_ONLY   0x0000000000000001ULL
 134 #define EFI_FILE_HIDDEN      0x0000000000000002ULL
 135 #define EFI_FILE_SYSTEM      0x0000000000000004ULL
 136 #define EFI_FILE_RESERVED    0x0000000000000008ULL
 137 #define EFI_FILE_DIRECTORY   0x0000000000000010ULL
 138 #define EFI_FILE_ARCHIVE     0x0000000000000020ULL
 139 #define EFI_FILE_VALID_ATTR  0x0000000000000037ULL
 140
 141 /**
 142   Closes a specified file handle.
 143
 144   @param  This          A pointer to the EFI_FILE_PROTOCOL instance that is the file
 145                         handle to close.
 146
 147   @retval EFI_SUCCESS   The file was closed.
 148
 149 **/
 150 typedef
 151 EFI_STATUS
 152 (EFIAPI *EFI_FILE_CLOSE)(
 153   IN EFI_FILE_PROTOCOL  *This
 154   );
 155
 156 /**
 157   Close and delete the file handle.
 158
 159   @param  This                     A pointer to the EFI_FILE_PROTOCOL instance that is the
 160                                    handle to the file to delete.
 161
 162   @retval EFI_SUCCESS              The file was closed and deleted, and the handle was closed.
 163   @retval EFI_WARN_DELETE_FAILURE  The handle was closed, but the file was not deleted.
 164
 165 **/
 166 typedef
 167 EFI_STATUS
 168 (EFIAPI *EFI_FILE_DELETE)(
 169   IN EFI_FILE_PROTOCOL  *This
 170   );
 171
 172 /**
 173   Reads data from a file.
 174
 175   @param  This       A pointer to the EFI_FILE_PROTOCOL instance that is the file
 176                      handle to read data from.
 177   @param  BufferSize On input, the size of the Buffer. On output, the amount of data
 178                      returned in Buffer. In both cases, the size is measured in bytes.
 179   @param  Buffer     The buffer into which the data is read.
 180
 181   @retval EFI_SUCCESS          Data was read.
 182   @retval EFI_NO_MEDIA         The device has no medium.
 183   @retval EFI_DEVICE_ERROR     The device reported an error.
 184   @retval EFI_DEVICE_ERROR     An attempt was made to read from a deleted file.
 185   @retval EFI_DEVICE_ERROR     On entry, the current file position is beyond the end of the file.
 186   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 187   @retval EFI_BUFFER_TOO_SMALL The BufferSize is too small to read the current directory
 188                                entry. BufferSize has been updated with the size
 189                                needed to complete the request.
 190
 191 **/
 192 typedef
 193 EFI_STATUS
 194 (EFIAPI *EFI_FILE_READ)(
 195   IN EFI_FILE_PROTOCOL        *This,
 196   IN OUT UINTN                *BufferSize,
 197   OUT VOID                    *Buffer
 198   );
 199
 200 /**
 201   Writes data to a file.
 202
 203   @param  This       A pointer to the EFI_FILE_PROTOCOL instance that is the file
 204                      handle to write data to.
 205   @param  BufferSize On input, the size of the Buffer. On output, the amount of data
 206                      actually written. In both cases, the size is measured in bytes.
 207   @param  Buffer     The buffer of data to write.
 208
 209   @retval EFI_SUCCESS          Data was written.
 210   @retval EFI_UNSUPPORTED      Writes to open directory files are not supported.
 211   @retval EFI_NO_MEDIA         The device has no medium.
 212   @retval EFI_DEVICE_ERROR     The device reported an error.
 213   @retval EFI_DEVICE_ERROR     An attempt was made to write to a deleted file.
 214   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 215   @retval EFI_WRITE_PROTECTED  The file or medium is write-protected.
 216   @retval EFI_ACCESS_DENIED    The file was opened read only.
 217   @retval EFI_VOLUME_FULL      The volume is full.
 218
 219 **/
 220 typedef
 221 EFI_STATUS
 222 (EFIAPI *EFI_FILE_WRITE)(
 223   IN EFI_FILE_PROTOCOL        *This,
 224   IN OUT UINTN                *BufferSize,
 225   IN VOID                     *Buffer
 226   );
 227
 228 /**
 229   Sets a file's current position.
 230
 231   @param  This            A pointer to the EFI_FILE_PROTOCOL instance that is the
 232                           file handle to set the requested position on.
 233   @param  Position        The byte position from the start of the file to set.
 234
 235   @retval EFI_SUCCESS      The position was set.
 236   @retval EFI_UNSUPPORTED  The seek request for nonzero is not valid on open
 237                            directories.
 238   @retval EFI_DEVICE_ERROR An attempt was made to set the position of a deleted file.
 239
 240 **/
 241 typedef
 242 EFI_STATUS
 243 (EFIAPI *EFI_FILE_SET_POSITION)(
 244   IN EFI_FILE_PROTOCOL        *This,
 245   IN UINT64                   Position
 246   );
 247
 248 /**
 249   Returns a file's current position.
 250
 251   @param  This            A pointer to the EFI_FILE_PROTOCOL instance that is the file
 252                           handle to get the current position on.
 253   @param  Position        The address to return the file's current position value.
 254
 255   @retval EFI_SUCCESS      The position was returned.
 256   @retval EFI_UNSUPPORTED  The request is not valid on open directories.
 257   @retval EFI_DEVICE_ERROR An attempt was made to get the position from a deleted file.
 258
 259 **/
 260 typedef
 261 EFI_STATUS
 262 (EFIAPI *EFI_FILE_GET_POSITION)(
 263   IN EFI_FILE_PROTOCOL        *This,
 264   OUT UINT64                  *Position
 265   );
 266
 267 /**
 268   Returns information about a file.
 269
 270   @param  This            A pointer to the EFI_FILE_PROTOCOL instance that is the file
 271                           handle the requested information is for.
 272   @param  InformationType The type identifier for the information being requested.
 273   @param  BufferSize      On input, the size of Buffer. On output, the amount of data
 274                           returned in Buffer. In both cases, the size is measured in bytes.
 275   @param  Buffer          A pointer to the data buffer to return. The buffer's type is
 276                           indicated by InformationType.
 277
 278   @retval EFI_SUCCESS          The information was returned.
 279   @retval EFI_UNSUPPORTED      The InformationType is not known.
 280   @retval EFI_NO_MEDIA         The device has no medium.
 281   @retval EFI_DEVICE_ERROR     The device reported an error.
 282   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 283   @retval EFI_BUFFER_TOO_SMALL The BufferSize is too small to read the current directory entry.
 284                                BufferSize has been updated with the size needed to complete
 285                                the request.
 286 **/
 287 typedef
 288 EFI_STATUS
 289 (EFIAPI *EFI_FILE_GET_INFO)(
 290   IN EFI_FILE_PROTOCOL        *This,
 291   IN EFI_GUID                 *InformationType,
 292   IN OUT UINTN                *BufferSize,
 293   OUT VOID                    *Buffer
 294   );
 295
 296 /**
 297   Sets information about a file.
 298
 299   @param  File            A pointer to the EFI_FILE_PROTOCOL instance that is the file
 300                           handle the information is for.
 301   @param  InformationType The type identifier for the information being set.
 302   @param  BufferSize      The size, in bytes, of Buffer.
 303   @param  Buffer          A pointer to the data buffer to write. The buffer's type is
 304                           indicated by InformationType.
 305
 306   @retval EFI_SUCCESS          The information was set.
 307   @retval EFI_UNSUPPORTED      The InformationType is not known.
 308   @retval EFI_NO_MEDIA         The device has no medium.
 309   @retval EFI_DEVICE_ERROR     The device reported an error.
 310   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 311   @retval EFI_WRITE_PROTECTED  InformationType is EFI_FILE_INFO_ID and the media is
 312                                read-only.
 313   @retval EFI_WRITE_PROTECTED  InformationType is EFI_FILE_PROTOCOL_SYSTEM_INFO_ID
 314                                and the media is read only.
 315   @retval EFI_WRITE_PROTECTED  InformationType is EFI_FILE_SYSTEM_VOLUME_LABEL_ID
 316                                and the media is read-only.
 317   @retval EFI_ACCESS_DENIED    An attempt is made to change the name of a file to a
 318                                file that is already present.
 319   @retval EFI_ACCESS_DENIED    An attempt is being made to change the EFI_FILE_DIRECTORY
 320                                Attribute.
 321   @retval EFI_ACCESS_DENIED    An attempt is being made to change the size of a directory.
 322   @retval EFI_ACCESS_DENIED    InformationType is EFI_FILE_INFO_ID and the file was opened
 323                                read-only and an attempt is being made to modify a field
 324                                other than Attribute.
 325   @retval EFI_VOLUME_FULL      The volume is full.
 326   @retval EFI_BAD_BUFFER_SIZE  BufferSize is smaller than the size of the type indicated
 327                                by InformationType.
 328
 329 **/
 330 typedef
 331 EFI_STATUS
 332 (EFIAPI *EFI_FILE_SET_INFO)(
 333   IN EFI_FILE_PROTOCOL        *This,
 334   IN EFI_GUID                 *InformationType,
 335   IN UINTN                    BufferSize,
 336   IN VOID                     *Buffer
 337   );
 338
 339 /**
 340   Flushes all modified data associated with a file to a device.
 341
 342   @param  This A pointer to the EFI_FILE_PROTOCOL instance that is the file
 343                handle to flush.
 344
 345   @retval EFI_SUCCESS          The data was flushed.
 346   @retval EFI_NO_MEDIA         The device has no medium.
 347   @retval EFI_DEVICE_ERROR     The device reported an error.
 348   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 349   @retval EFI_WRITE_PROTECTED  The file or medium is write-protected.
 350   @retval EFI_ACCESS_DENIED    The file was opened read-only.
 351   @retval EFI_VOLUME_FULL      The volume is full.
 352
 353 **/
 354 typedef
 355 EFI_STATUS
 356 (EFIAPI *EFI_FILE_FLUSH)(
 357   IN EFI_FILE_PROTOCOL  *This
 358   );
 359
 360 typedef struct {
 361   //
 362   // If Event is NULL, then blocking I/O is performed.
 363   // If Event is not NULL and non-blocking I/O is supported, then non-blocking I/O is performed,
 364   // and Event will be signaled when the read request is completed.
 365   // The caller must be prepared to handle the case where the callback associated with Event
 366   // occurs before the original asynchronous I/O request call returns.
 367   //
 368   EFI_EVENT     Event;
 369
 370   //
 371   // Defines whether or not the signaled event encountered an error.
 372   //
 373   EFI_STATUS    Status;
 374
 375   //
 376   // For OpenEx():  Not Used, ignored.
 377   // For ReadEx():  On input, the size of the Buffer. On output, the amount of data returned in Buffer.
 378   //                In both cases, the size is measured in bytes.
 379   // For WriteEx(): On input, the size of the Buffer. On output, the amount of data actually written.
 380   //                In both cases, the size is measured in bytes.
 381   // For FlushEx(): Not used, ignored.
 382   //
 383   UINTN    BufferSize;
 384
 385   //
 386   // For OpenEx():  Not Used, ignored.
 387   // For ReadEx():  The buffer into which the data is read.
 388   // For WriteEx(): The buffer of data to write.
 389   // For FlushEx(): Not Used, ignored.
 390   //
 391   VOID     *Buffer;
 392 } EFI_FILE_IO_TOKEN;
 393
 394 /**
 395   Opens a new file relative to the source directory's location.
 396
 397   @param  This       A pointer to the EFI_FILE_PROTOCOL instance that is the file
 398                      handle to the source location.
 399   @param  NewHandle  A pointer to the location to return the opened handle for the new
 400                      file.
 401   @param  FileName   The Null-terminated string of the name of the file to be opened.
 402                      The file name may contain the following path modifiers: "\", ".",
 403                      and "..".
 404   @param  OpenMode   The mode to open the file. The only valid combinations that the
 405                      file may be opened with are: Read, Read/Write, or Create/Read/Write.
 406   @param  Attributes Only valid for EFI_FILE_MODE_CREATE, in which case these are the
 407                      attribute bits for the newly created file.
 408   @param  Token      A pointer to the token associated with the transaction.
 409
 410   @retval EFI_SUCCESS          If Event is NULL (blocking I/O): The data was read successfully.
 411                                If Event is not NULL (asynchronous I/O): The request was successfully
 412                                                                         queued for processing.
 413   @retval EFI_NOT_FOUND        The specified file could not be found on the device.
 414   @retval EFI_NO_MEDIA         The device has no medium.
 415   @retval EFI_MEDIA_CHANGED    The device has a different medium in it or the medium is no
 416                                longer supported.
 417   @retval EFI_DEVICE_ERROR     The device reported an error.
 418   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 419   @retval EFI_WRITE_PROTECTED  An attempt was made to create a file, or open a file for write
 420                                when the media is write-protected.
 421   @retval EFI_ACCESS_DENIED    The service denied access to the file.
 422   @retval EFI_OUT_OF_RESOURCES Not enough resources were available to open the file.
 423   @retval EFI_VOLUME_FULL      The volume is full.
 424
 425 **/
 426 typedef
 427 EFI_STATUS
 428 (EFIAPI *EFI_FILE_OPEN_EX)(
 429   IN EFI_FILE_PROTOCOL        *This,
 430   OUT EFI_FILE_PROTOCOL       **NewHandle,
 431   IN CHAR16                   *FileName,
 432   IN UINT64                   OpenMode,
 433   IN UINT64                   Attributes,
 434   IN OUT EFI_FILE_IO_TOKEN    *Token
 435   );
 436
 437 /**
 438   Reads data from a file.
 439
 440   @param  This       A pointer to the EFI_FILE_PROTOCOL instance that is the file handle to read data from.
 441   @param  Token      A pointer to the token associated with the transaction.
 442
 443   @retval EFI_SUCCESS          If Event is NULL (blocking I/O): The data was read successfully.
 444                                If Event is not NULL (asynchronous I/O): The request was successfully
 445                                                                         queued for processing.
 446   @retval EFI_NO_MEDIA         The device has no medium.
 447   @retval EFI_DEVICE_ERROR     The device reported an error.
 448   @retval EFI_DEVICE_ERROR     An attempt was made to read from a deleted file.
 449   @retval EFI_DEVICE_ERROR     On entry, the current file position is beyond the end of the file.
 450   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 451   @retval EFI_OUT_OF_RESOURCES Unable to queue the request due to lack of resources.
 452 **/
 453 typedef
 454 EFI_STATUS
 455 (EFIAPI *EFI_FILE_READ_EX)(
 456   IN EFI_FILE_PROTOCOL        *This,
 457   IN OUT EFI_FILE_IO_TOKEN    *Token
 458   );
 459
 460 /**
 461   Writes data to a file.
 462
 463   @param  This       A pointer to the EFI_FILE_PROTOCOL instance that is the file handle to write data to.
 464   @param  Token      A pointer to the token associated with the transaction.
 465
 466   @retval EFI_SUCCESS          If Event is NULL (blocking I/O): The data was read successfully.
 467                                If Event is not NULL (asynchronous I/O): The request was successfully
 468                                                                         queued for processing.
 469   @retval EFI_UNSUPPORTED      Writes to open directory files are not supported.
 470   @retval EFI_NO_MEDIA         The device has no medium.
 471   @retval EFI_DEVICE_ERROR     The device reported an error.
 472   @retval EFI_DEVICE_ERROR     An attempt was made to write to a deleted file.
 473   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 474   @retval EFI_WRITE_PROTECTED  The file or medium is write-protected.
 475   @retval EFI_ACCESS_DENIED    The file was opened read only.
 476   @retval EFI_VOLUME_FULL      The volume is full.
 477   @retval EFI_OUT_OF_RESOURCES Unable to queue the request due to lack of resources.
 478 **/
 479 typedef
 480 EFI_STATUS
 481 (EFIAPI *EFI_FILE_WRITE_EX)(
 482   IN EFI_FILE_PROTOCOL        *This,
 483   IN OUT EFI_FILE_IO_TOKEN    *Token
 484   );
 485
 486 /**
 487   Flushes all modified data associated with a file to a device.
 488
 489   @param  This  A pointer to the EFI_FILE_PROTOCOL instance that is the file
 490                 handle to flush.
 491   @param  Token A pointer to the token associated with the transaction.
 492
 493   @retval EFI_SUCCESS          If Event is NULL (blocking I/O): The data was read successfully.
 494                                If Event is not NULL (asynchronous I/O): The request was successfully
 495                                                                         queued for processing.
 496   @retval EFI_NO_MEDIA         The device has no medium.
 497   @retval EFI_DEVICE_ERROR     The device reported an error.
 498   @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
 499   @retval EFI_WRITE_PROTECTED  The file or medium is write-protected.
 500   @retval EFI_ACCESS_DENIED    The file was opened read-only.
 501   @retval EFI_VOLUME_FULL      The volume is full.
 502   @retval EFI_OUT_OF_RESOURCES Unable to queue the request due to lack of resources.
 503
 504 **/
 505 typedef
 506 EFI_STATUS
 507 (EFIAPI *EFI_FILE_FLUSH_EX)(
 508   IN EFI_FILE_PROTOCOL        *This,
 509   IN OUT EFI_FILE_IO_TOKEN    *Token
 510   );
 511
 512 #define EFI_FILE_PROTOCOL_REVISION         0x00010000
 513 #define EFI_FILE_PROTOCOL_REVISION2        0x00020000
 514 #define EFI_FILE_PROTOCOL_LATEST_REVISION  EFI_FILE_PROTOCOL_REVISION2
 515
 516 //
 517 // Revision defined in EFI1.1.
 518 //
 519 #define EFI_FILE_REVISION  EFI_FILE_PROTOCOL_REVISION
 520
 521 ///
 522 /// The EFI_FILE_PROTOCOL provides file IO access to supported file systems.
 523 /// An EFI_FILE_PROTOCOL provides access to a file's or directory's contents,
 524 /// and is also a reference to a location in the directory tree of the file system
 525 /// in which the file resides. With any given file handle, other files may be opened
 526 /// relative to this file's location, yielding new file handles.
 527 ///
 528 struct _EFI_FILE_PROTOCOL {
 529   ///
 530   /// The version of the EFI_FILE_PROTOCOL interface. The version specified
 531   /// by this specification is EFI_FILE_PROTOCOL_LATEST_REVISION.
 532   /// Future versions are required to be backward compatible to version 1.0.
 533   ///
 534   UINT64                   Revision;
 535   EFI_FILE_OPEN            Open;
 536   EFI_FILE_CLOSE           Close;
 537   EFI_FILE_DELETE          Delete;
 538   EFI_FILE_READ            Read;
 539   EFI_FILE_WRITE           Write;
 540   EFI_FILE_GET_POSITION    GetPosition;
 541   EFI_FILE_SET_POSITION    SetPosition;
 542   EFI_FILE_GET_INFO        GetInfo;
 543   EFI_FILE_SET_INFO        SetInfo;
 544   EFI_FILE_FLUSH           Flush;
 545   EFI_FILE_OPEN_EX         OpenEx;
 546   EFI_FILE_READ_EX         ReadEx;
 547   EFI_FILE_WRITE_EX        WriteEx;
 548   EFI_FILE_FLUSH_EX        FlushEx;
 549 };
 550
 551 extern EFI_GUID  gEfiSimpleFileSystemProtocolGuid;
 552
 553 #endif