]>
Commit | Line | Data |
---|---|---|
50944545 | 1 | /** @file |
2 | File System Access for NvVarsFileLib | |
3 | ||
ea5396f3 | 4 | Copyright (c) 2004 - 2014, Intel Corporation. All rights reserved.<BR> |
56d7640a | 5 | This program and the accompanying materials |
50944545 | 6 | are licensed and made available under the terms and conditions of the BSD License |
7 | which accompanies this distribution. The full text of the license may be found at | |
8 | http://opensource.org/licenses/bsd-license.php | |
9 | ||
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
12 | ||
13 | **/ | |
14 | ||
15 | #include "NvVarsFileLib.h" | |
16 | ||
17 | #include <Library/BaseMemoryLib.h> | |
18 | #include <Library/DebugLib.h> | |
19 | #include <Library/MemoryAllocationLib.h> | |
20 | ||
21 | ||
22 | /** | |
23 | Open the NvVars file for reading or writing | |
24 | ||
25 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
26 | @param[in] ReadingFile - TRUE: open the file for reading. FALSE: writing | |
27 | @param[out] NvVarsFile - If EFI_SUCCESS is returned, then this is updated | |
28 | with the opened NvVars file. | |
29 | ||
30 | @return EFI_SUCCESS if the file was opened | |
31 | ||
32 | **/ | |
33 | EFI_STATUS | |
34 | GetNvVarsFile ( | |
35 | IN EFI_HANDLE FsHandle, | |
36 | IN BOOLEAN ReadingFile, | |
37 | OUT EFI_FILE_HANDLE *NvVarsFile | |
38 | ) | |
39 | { | |
40 | EFI_STATUS Status; | |
41 | EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *Fs; | |
42 | EFI_FILE_HANDLE Root; | |
43 | ||
44 | // | |
45 | // Get the FileSystem protocol on that handle | |
46 | // | |
47 | Status = gBS->HandleProtocol ( | |
48 | FsHandle, | |
49 | &gEfiSimpleFileSystemProtocolGuid, | |
50 | (VOID **)&Fs | |
51 | ); | |
52 | if (EFI_ERROR (Status)) { | |
53 | return Status; | |
54 | } | |
55 | ||
56 | // | |
57 | // Get the volume (the root directory) | |
58 | // | |
59 | Status = Fs->OpenVolume (Fs, &Root); | |
60 | if (EFI_ERROR (Status)) { | |
61 | return Status; | |
62 | } | |
63 | ||
64 | // | |
65 | // Attempt to open the NvVars file in the root directory | |
66 | // | |
67 | Status = Root->Open ( | |
68 | Root, | |
69 | NvVarsFile, | |
70 | L"NvVars", | |
71 | ReadingFile ? | |
72 | EFI_FILE_MODE_READ : | |
73 | ( | |
74 | EFI_FILE_MODE_CREATE | | |
75 | EFI_FILE_MODE_READ | | |
76 | EFI_FILE_MODE_WRITE | |
77 | ), | |
78 | 0 | |
79 | ); | |
80 | if (EFI_ERROR (Status)) { | |
81 | return Status; | |
82 | } | |
83 | ||
84 | return Status; | |
85 | } | |
86 | ||
87 | ||
88 | /** | |
89 | Open the NvVars file for reading or writing | |
90 | ||
91 | @param[in] File - The file to inspect | |
92 | @param[out] Exists - Returns whether the file exists | |
93 | @param[out] Size - Returns the size of the file | |
94 | (0 if the file does not exist) | |
95 | ||
96 | **/ | |
97 | VOID | |
98 | NvVarsFileReadCheckup ( | |
99 | IN EFI_FILE_HANDLE File, | |
100 | OUT BOOLEAN *Exists, | |
101 | OUT UINTN *Size | |
102 | ) | |
103 | { | |
104 | EFI_FILE_INFO *FileInfo; | |
105 | ||
106 | *Exists = FALSE; | |
107 | *Size = 0; | |
108 | ||
109 | FileInfo = FileHandleGetInfo (File); | |
110 | if (FileInfo == NULL) { | |
111 | return; | |
112 | } | |
113 | ||
114 | if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) != 0) { | |
115 | FreePool (FileInfo); | |
116 | return; | |
117 | } | |
118 | ||
119 | *Exists = TRUE; | |
7d9cf3f2 | 120 | *Size = (UINTN) FileInfo->FileSize; |
50944545 | 121 | |
122 | FreePool (FileInfo); | |
123 | } | |
124 | ||
125 | ||
126 | /** | |
127 | Open the NvVars file for reading or writing | |
128 | ||
129 | @param[in] File - The file to inspect | |
130 | @param[out] Exists - Returns whether the file exists | |
131 | @param[out] Size - Returns the size of the file | |
132 | (0 if the file does not exist) | |
133 | ||
134 | **/ | |
135 | EFI_STATUS | |
136 | FileHandleEmpty ( | |
137 | IN EFI_FILE_HANDLE File | |
138 | ) | |
139 | { | |
140 | EFI_STATUS Status; | |
141 | EFI_FILE_INFO *FileInfo; | |
142 | ||
143 | // | |
144 | // Retrieve the FileInfo structure | |
145 | // | |
146 | FileInfo = FileHandleGetInfo (File); | |
147 | if (FileInfo == NULL) { | |
148 | return EFI_INVALID_PARAMETER; | |
149 | } | |
150 | ||
151 | // | |
152 | // If the path is a directory, then return an error | |
153 | // | |
154 | if ((FileInfo->Attribute & EFI_FILE_DIRECTORY) != 0) { | |
155 | FreePool (FileInfo); | |
156 | return EFI_INVALID_PARAMETER; | |
157 | } | |
158 | ||
159 | // | |
160 | // If the file size is already 0, then it is empty, so | |
161 | // we can return success. | |
162 | // | |
163 | if (FileInfo->FileSize == 0) { | |
164 | FreePool (FileInfo); | |
165 | return EFI_SUCCESS; | |
166 | } | |
167 | ||
168 | // | |
169 | // Set the file size to 0. | |
170 | // | |
171 | FileInfo->FileSize = 0; | |
172 | Status = FileHandleSetInfo (File, FileInfo); | |
173 | ||
174 | FreePool (FileInfo); | |
175 | ||
176 | return Status; | |
177 | } | |
178 | ||
179 | ||
180 | /** | |
181 | Reads a file to a newly allocated buffer | |
182 | ||
183 | @param[in] File - The file to read | |
184 | @param[in] ReadSize - The size of data to read from the file | |
185 | ||
186 | @return Pointer to buffer allocated to hold the file | |
187 | contents. NULL if an error occured. | |
188 | ||
189 | **/ | |
190 | VOID* | |
191 | FileHandleReadToNewBuffer ( | |
192 | IN EFI_FILE_HANDLE FileHandle, | |
193 | IN UINTN ReadSize | |
194 | ) | |
195 | { | |
196 | EFI_STATUS Status; | |
197 | UINTN ActualReadSize; | |
198 | VOID *FileContents; | |
199 | ||
200 | ActualReadSize = ReadSize; | |
201 | FileContents = AllocatePool (ReadSize); | |
202 | if (FileContents != NULL) { | |
203 | Status = FileHandleRead ( | |
204 | FileHandle, | |
205 | &ReadSize, | |
206 | FileContents | |
207 | ); | |
208 | if (EFI_ERROR (Status) || (ActualReadSize != ReadSize)) { | |
209 | FreePool (FileContents); | |
210 | return NULL; | |
211 | } | |
212 | } | |
213 | ||
214 | return FileContents; | |
215 | } | |
216 | ||
217 | ||
218 | /** | |
219 | Reads the contents of the NvVars file on the file system | |
220 | ||
221 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
222 | ||
223 | @return EFI_STATUS based on the success or failure of the file read | |
224 | ||
225 | **/ | |
226 | EFI_STATUS | |
227 | ReadNvVarsFile ( | |
228 | IN EFI_HANDLE FsHandle | |
229 | ) | |
230 | { | |
231 | EFI_STATUS Status; | |
232 | EFI_FILE_HANDLE File; | |
233 | UINTN FileSize; | |
234 | BOOLEAN FileExists; | |
235 | VOID *FileContents; | |
59b19469 | 236 | EFI_HANDLE SerializedVariables; |
50944545 | 237 | |
238 | Status = GetNvVarsFile (FsHandle, TRUE, &File); | |
239 | if (EFI_ERROR (Status)) { | |
240 | DEBUG ((EFI_D_INFO, "FsAccess.c: Could not open NV Variables file on this file system\n")); | |
241 | return Status; | |
242 | } | |
243 | ||
244 | NvVarsFileReadCheckup (File, &FileExists, &FileSize); | |
245 | if (FileSize == 0) { | |
246 | FileHandleClose (File); | |
247 | return EFI_UNSUPPORTED; | |
248 | } | |
249 | ||
250 | FileContents = FileHandleReadToNewBuffer (File, FileSize); | |
251 | if (FileContents == NULL) { | |
252 | FileHandleClose (File); | |
253 | return EFI_UNSUPPORTED; | |
254 | } | |
255 | ||
256 | DEBUG (( | |
257 | EFI_D_INFO, | |
6394c35a LE |
258 | "FsAccess.c: Read %Lu bytes from NV Variables file\n", |
259 | (UINT64)FileSize | |
50944545 | 260 | )); |
261 | ||
59b19469 | 262 | Status = SerializeVariablesNewInstanceFromBuffer ( |
263 | &SerializedVariables, | |
264 | FileContents, | |
265 | FileSize | |
266 | ); | |
267 | if (!RETURN_ERROR (Status)) { | |
268 | Status = SerializeVariablesSetSerializedVariables (SerializedVariables); | |
269 | } | |
50944545 | 270 | |
271 | FreePool (FileContents); | |
272 | FileHandleClose (File); | |
273 | ||
274 | return Status; | |
275 | } | |
276 | ||
277 | ||
6bc7a088 JJ |
278 | /** |
279 | Writes a variable to indicate that the NV variables | |
280 | have been loaded from the file system. | |
281 | ||
282 | **/ | |
283 | STATIC | |
284 | VOID | |
285 | SetNvVarsVariable ( | |
286 | VOID | |
287 | ) | |
288 | { | |
289 | BOOLEAN VarData; | |
290 | UINTN Size; | |
291 | ||
292 | // | |
293 | // Write a variable to indicate we've already loaded the | |
294 | // variable data. If it is found, we skip the loading on | |
295 | // subsequent attempts. | |
296 | // | |
297 | Size = sizeof (VarData); | |
298 | VarData = TRUE; | |
299 | gRT->SetVariable ( | |
300 | L"NvVars", | |
301 | &gEfiSimpleFileSystemProtocolGuid, | |
302 | EFI_VARIABLE_NON_VOLATILE | | |
303 | EFI_VARIABLE_BOOTSERVICE_ACCESS | | |
304 | EFI_VARIABLE_RUNTIME_ACCESS, | |
305 | Size, | |
306 | (VOID*) &VarData | |
307 | ); | |
308 | } | |
309 | ||
310 | ||
50944545 | 311 | /** |
312 | Loads the non-volatile variables from the NvVars file on the | |
313 | given file system. | |
314 | ||
315 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
316 | ||
317 | @return EFI_STATUS based on the success or failure of load operation | |
318 | ||
319 | **/ | |
320 | EFI_STATUS | |
321 | LoadNvVarsFromFs ( | |
322 | EFI_HANDLE FsHandle | |
323 | ) | |
324 | { | |
325 | EFI_STATUS Status; | |
326 | BOOLEAN VarData; | |
327 | UINTN Size; | |
328 | ||
329 | DEBUG ((EFI_D_INFO, "FsAccess.c: LoadNvVarsFromFs\n")); | |
330 | ||
331 | // | |
332 | // We write a variable to indicate we've already loaded the | |
333 | // variable data. If it is found, we skip the loading. | |
334 | // | |
335 | // This is relevent if the non-volatile variable have been | |
336 | // able to survive a reboot operation. In that case, we don't | |
337 | // want to re-load the file as it would overwrite newer changes | |
338 | // made to the variables. | |
339 | // | |
340 | Size = sizeof (VarData); | |
341 | VarData = TRUE; | |
342 | Status = gRT->GetVariable ( | |
343 | L"NvVars", | |
344 | &gEfiSimpleFileSystemProtocolGuid, | |
345 | NULL, | |
346 | &Size, | |
347 | (VOID*) &VarData | |
348 | ); | |
349 | if (Status == EFI_SUCCESS) { | |
350 | DEBUG ((EFI_D_INFO, "NV Variables were already loaded\n")); | |
351 | return EFI_ALREADY_STARTED; | |
352 | } | |
353 | ||
354 | // | |
355 | // Attempt to restore the variables from the NvVars file. | |
356 | // | |
357 | Status = ReadNvVarsFile (FsHandle); | |
358 | if (EFI_ERROR (Status)) { | |
359 | DEBUG ((EFI_D_INFO, "Error while restoring NV variable data\n")); | |
360 | return Status; | |
361 | } | |
362 | ||
363 | // | |
364 | // Write a variable to indicate we've already loaded the | |
365 | // variable data. If it is found, we skip the loading on | |
366 | // subsequent attempts. | |
367 | // | |
6bc7a088 | 368 | SetNvVarsVariable(); |
50944545 | 369 | |
370 | DEBUG (( | |
371 | EFI_D_INFO, | |
6394c35a LE |
372 | "FsAccess.c: Read NV Variables file (size=%Lu)\n", |
373 | (UINT64)Size | |
50944545 | 374 | )); |
375 | ||
376 | return Status; | |
377 | } | |
378 | ||
379 | ||
59b19469 | 380 | STATIC |
381 | RETURN_STATUS | |
382 | EFIAPI | |
383 | IterateVariablesCallbackAddAllNvVariables ( | |
384 | IN VOID *Context, | |
385 | IN CHAR16 *VariableName, | |
386 | IN EFI_GUID *VendorGuid, | |
387 | IN UINT32 Attributes, | |
388 | IN UINTN DataSize, | |
389 | IN VOID *Data | |
390 | ) | |
391 | { | |
392 | EFI_HANDLE Instance; | |
393 | ||
394 | Instance = (EFI_HANDLE) Context; | |
395 | ||
396 | // | |
397 | // Only save non-volatile variables | |
398 | // | |
399 | if ((Attributes & EFI_VARIABLE_NON_VOLATILE) == 0) { | |
400 | return RETURN_SUCCESS; | |
401 | } | |
402 | ||
403 | return SerializeVariablesAddVariable ( | |
404 | Instance, | |
405 | VariableName, | |
406 | VendorGuid, | |
407 | Attributes, | |
408 | DataSize, | |
409 | Data | |
410 | ); | |
411 | } | |
412 | ||
413 | ||
50944545 | 414 | /** |
415 | Saves the non-volatile variables into the NvVars file on the | |
416 | given file system. | |
417 | ||
418 | @param[in] FsHandle - Handle for a gEfiSimpleFileSystemProtocolGuid instance | |
419 | ||
420 | @return EFI_STATUS based on the success or failure of load operation | |
421 | ||
422 | **/ | |
423 | EFI_STATUS | |
424 | SaveNvVarsToFs ( | |
425 | EFI_HANDLE FsHandle | |
426 | ) | |
427 | { | |
428 | EFI_STATUS Status; | |
429 | EFI_FILE_HANDLE File; | |
59b19469 | 430 | UINTN WriteSize; |
50944545 | 431 | UINTN VariableDataSize; |
432 | VOID *VariableData; | |
59b19469 | 433 | EFI_HANDLE SerializedVariables; |
434 | ||
ea5396f3 RN |
435 | SerializedVariables = NULL; |
436 | ||
59b19469 | 437 | Status = SerializeVariablesNewInstance (&SerializedVariables); |
438 | if (EFI_ERROR (Status)) { | |
439 | return Status; | |
440 | } | |
441 | ||
442 | Status = SerializeVariablesIterateSystemVariables ( | |
443 | IterateVariablesCallbackAddAllNvVariables, | |
444 | (VOID*) SerializedVariables | |
445 | ); | |
446 | if (EFI_ERROR (Status)) { | |
447 | return Status; | |
448 | } | |
449 | ||
450 | VariableData = NULL; | |
451 | VariableDataSize = 0; | |
452 | Status = SerializeVariablesToBuffer ( | |
453 | SerializedVariables, | |
454 | NULL, | |
455 | &VariableDataSize | |
456 | ); | |
457 | if (Status == RETURN_BUFFER_TOO_SMALL) { | |
458 | VariableData = AllocatePool (VariableDataSize); | |
459 | if (VariableData == NULL) { | |
460 | Status = EFI_OUT_OF_RESOURCES; | |
461 | } else { | |
462 | Status = SerializeVariablesToBuffer ( | |
463 | SerializedVariables, | |
464 | VariableData, | |
465 | &VariableDataSize | |
466 | ); | |
467 | } | |
468 | } | |
469 | ||
470 | SerializeVariablesFreeInstance (SerializedVariables); | |
471 | ||
472 | if (EFI_ERROR (Status)) { | |
473 | return Status; | |
474 | } | |
50944545 | 475 | |
476 | // | |
477 | // Open the NvVars file for writing. | |
478 | // | |
479 | Status = GetNvVarsFile (FsHandle, FALSE, &File); | |
480 | if (EFI_ERROR (Status)) { | |
481 | DEBUG ((EFI_D_INFO, "FsAccess.c: Unable to open file to saved NV Variables\n")); | |
482 | return Status; | |
483 | } | |
484 | ||
485 | // | |
486 | // Empty the starting file contents. | |
487 | // | |
488 | Status = FileHandleEmpty (File); | |
489 | if (EFI_ERROR (Status)) { | |
490 | FileHandleClose (File); | |
491 | return Status; | |
492 | } | |
493 | ||
59b19469 | 494 | WriteSize = VariableDataSize; |
495 | Status = FileHandleWrite (File, &WriteSize, VariableData); | |
496 | if (EFI_ERROR (Status)) { | |
497 | return Status; | |
50944545 | 498 | } |
499 | ||
500 | FileHandleClose (File); | |
501 | ||
502 | if (!EFI_ERROR (Status)) { | |
6bc7a088 JJ |
503 | // |
504 | // Write a variable to indicate we've already loaded the | |
505 | // variable data. If it is found, we skip the loading on | |
506 | // subsequent attempts. | |
507 | // | |
508 | SetNvVarsVariable(); | |
509 | ||
50944545 | 510 | DEBUG ((EFI_D_INFO, "Saved NV Variables to NvVars file\n")); |
511 | } | |
512 | ||
513 | return Status; | |
514 | ||
515 | } | |
516 | ||
517 |