1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #include <stdint.h>
4 #include <string.h>
5 #include <console/console.h>
6
7 #include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Uefi/UefiBaseType.h>
8 #include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Uefi/UefiMultiPhase.h>
9 #include <vendorcode/intel/edk2/UDK2017/MdePkg/Include/Pi/PiFirmwareVolume.h>
10 #include <vendorcode/intel/edk2/UDK2017/MdeModulePkg/Include/Guid/VariableFormat.h>
11
12 #include "efivars.h"
13
14 #define PREFIX "EFIVARS: "
15
16 static const EFI_GUID EfiVariableGuid = {
17 0xddcf3616, 0x3275, 0x4164, { 0x98, 0xb6, 0xfe, 0x85, 0x70, 0x7f, 0xfe, 0x7d } };
18 static const EFI_GUID EfiAuthenticatedVariableGuid = {
19 0xaaf32c78, 0x947b, 0x439a, { 0xa1, 0x80, 0x2e, 0x14, 0x4e, 0xc3, 0x77, 0x92 } };
20 static const EFI_GUID EfiSystemNvDataFvGuid = {
21 0xfff12b8d, 0x7696, 0x4c8b, { 0xa9, 0x85, 0x27, 0x47, 0x07, 0x5b, 0x4f, 0x50 } };
22
print_guid(int log_level,const EFI_GUID * g)23 static void print_guid(int log_level, const EFI_GUID *g)
24 {
25 printk(log_level, "GUID: %08x-%04x-%04x-%02x%02x%02x%02x%02x%02x%02x%02x",
26 g->Data1, g->Data2, g->Data3, g->Data4[0], g->Data4[1], g->Data4[2],
27 g->Data4[3], g->Data4[4], g->Data4[5], g->Data4[6], g->Data4[7]);
28 }
29
compare_guid(const EFI_GUID * a,const EFI_GUID * b)30 static bool compare_guid(const EFI_GUID *a, const EFI_GUID *b)
31 {
32 return memcmp(a, b, sizeof(*a)) == 0;
33 }
34
35 /* Reads the CHAR16 string from rdev at offset and prints it */
rdev_print_wchar(int log_level,struct region_device * rdev,size_t offset)36 static enum cb_err rdev_print_wchar(int log_level, struct region_device *rdev, size_t offset)
37 {
38 CHAR16 c;
39 int i = 0;
40
41 /* Convert ASCII to UTF-16 */
42 do {
43 if (rdev_readat(rdev, &c, offset + i * sizeof(c), sizeof(c)) != sizeof(c))
44 return CB_EFI_ACCESS_ERROR;
45 if (c < 0x80)
46 printk(log_level, "%c", (char)c);
47 else
48 printk(log_level, "\\u%04x", c);
49
50 i++;
51 } while (c);
52 return CB_SUCCESS;
53 }
54
55 /* Convert an ASCII string to UTF-16 and write it to the rdev starting at offset. */
rdev_write_wchar(struct region_device * rdev,size_t offset,const char * msg)56 static enum cb_err rdev_write_wchar(struct region_device *rdev, size_t offset, const char *msg)
57 {
58 size_t i;
59 CHAR16 c;
60
61 /* Convert ASCII to UTF-16 */
62 for (i = 0; i < strlen(msg) + 1; i++) {
63 c = msg[i];
64
65 if (rdev_writeat(rdev, &c, offset + i * sizeof(c), sizeof(c)) != sizeof(c))
66 return CB_EFI_ACCESS_ERROR;
67 }
68 return CB_SUCCESS;
69 }
70
71 /* Read an UTF-16 string from rdev at offset and compare it to ASCII string */
rdev_strcmp_wchar_ascii(struct region_device * rdev,size_t offset,const char * msg)72 static int rdev_strcmp_wchar_ascii(struct region_device *rdev, size_t offset, const char *msg)
73 {
74 size_t i;
75 CHAR16 c;
76 int r;
77
78 i = 0;
79 /* Compare UTF-16 and ASCII */
80 while (1) {
81 if (rdev_readat(rdev, &c, offset + i * sizeof(c), sizeof(c)) != sizeof(c))
82 return CB_EFI_ACCESS_ERROR;
83 if ((r = (c - msg[i])) != 0 || !c)
84 break;
85
86 i++;
87 }
88 return r;
89 }
90
91 /* Compare an rdev region and a data buffer */
rdev_memcmp(struct region_device * rdev,size_t offset,uint8_t * data,size_t size)92 static int rdev_memcmp(struct region_device *rdev, size_t offset, uint8_t *data, size_t size)
93 {
94 uint8_t buf[16];
95 size_t i;
96 int r;
97
98 i = 0;
99 while (size >= sizeof(buf)) {
100 if (rdev_readat(rdev, buf, offset + i, sizeof(buf)) != sizeof(buf))
101 return CB_EFI_ACCESS_ERROR;
102 r = memcmp(buf, data + i, sizeof(buf));
103 if (r != 0)
104 return r;
105 i += sizeof(buf);
106 size -= sizeof(buf);
107 }
108 while (size > 0) {
109 if (rdev_readat(rdev, buf, offset + i, 1) != 1)
110 return CB_EFI_ACCESS_ERROR;
111 r = buf[0] - data[i];
112 if (r != 0)
113 return r;
114 i++;
115 size--;
116 }
117 return 0;
118 }
119
120
validate_fv_header(const struct region_device * rdev,EFI_FIRMWARE_VOLUME_HEADER * fw_vol_hdr)121 static enum cb_err validate_fv_header(const struct region_device *rdev,
122 EFI_FIRMWARE_VOLUME_HEADER *fw_vol_hdr)
123 {
124 uint16_t checksum, data;
125 size_t i;
126
127 if (rdev_readat(rdev, fw_vol_hdr, 0, sizeof(*fw_vol_hdr)) != sizeof(*fw_vol_hdr))
128 return CB_EFI_ACCESS_ERROR;
129
130 /*
131 * Verify the header revision, header signature, length
132 * Length of FvBlock cannot be 2**64-1
133 * HeaderLength cannot be an odd number
134 */
135 if ((fw_vol_hdr->Revision != EFI_FVH_REVISION)
136 || (fw_vol_hdr->Signature != EFI_FVH_SIGNATURE)
137 || (fw_vol_hdr->FvLength > region_device_sz(rdev))
138 || (fw_vol_hdr->HeaderLength > region_device_sz(rdev))
139 || (fw_vol_hdr->HeaderLength & 1)) {
140 printk(BIOS_WARNING, PREFIX "No Firmware Volume header present\n");
141 return CB_EFI_FVH_INVALID;
142 }
143
144 /* Check the Firmware Volume Guid */
145 if (!compare_guid(&fw_vol_hdr->FileSystemGuid, &EfiSystemNvDataFvGuid)) {
146 printk(BIOS_WARNING, PREFIX "Firmware Volume Guid non-compatible\n");
147 return CB_EFI_FVH_INVALID;
148 }
149
150 /* Verify the header checksum */
151 checksum = 0;
152 for (i = 0; i < fw_vol_hdr->HeaderLength; i += 2) {
153 if (rdev_readat(rdev, &data, i, sizeof(data)) != sizeof(data))
154 return CB_EFI_ACCESS_ERROR;
155 checksum = (uint16_t)(checksum + data); /* intentionally overflows */
156 }
157 if (checksum != 0) {
158 printk(BIOS_WARNING, PREFIX "FV checksum is invalid: 0x%X\n", checksum);
159 return CB_EFI_CHECKSUM_INVALID;
160 }
161
162 printk(BIOS_SPEW, PREFIX "UEFI FV with size %lld found\n", fw_vol_hdr->FvLength);
163
164 return CB_SUCCESS;
165 }
166
167 static enum cb_err
validate_variable_store_header(const EFI_FIRMWARE_VOLUME_HEADER * fv_hdr,struct region_device * rdev,bool * auth_format)168 validate_variable_store_header(const EFI_FIRMWARE_VOLUME_HEADER *fv_hdr,
169 struct region_device *rdev,
170 bool *auth_format)
171 {
172 VARIABLE_STORE_HEADER hdr;
173 size_t length;
174
175 if (rdev_readat(rdev, &hdr, fv_hdr->HeaderLength, sizeof(hdr)) != sizeof(hdr))
176 return CB_EFI_ACCESS_ERROR;
177
178 /* Check the Variable Store Guid */
179 if (!compare_guid(&hdr.Signature, &EfiVariableGuid) &&
180 !compare_guid(&hdr.Signature, &EfiAuthenticatedVariableGuid)) {
181 printk(BIOS_WARNING, PREFIX "Variable Store Guid non-compatible\n");
182 return CB_EFI_VS_CORRUPTED_INVALID;
183 }
184
185 *auth_format = compare_guid(&hdr.Signature, &EfiAuthenticatedVariableGuid);
186
187 length = region_device_sz(rdev) - fv_hdr->HeaderLength;
188 if (hdr.Size > length) {
189 printk(BIOS_WARNING, PREFIX "Variable Store Length does not match\n");
190 return CB_EFI_VS_CORRUPTED_INVALID;
191 }
192
193 if (hdr.Format != VARIABLE_STORE_FORMATTED)
194 return CB_EFI_VS_NOT_FORMATTED_INVALID;
195
196 if (hdr.State != VARIABLE_STORE_HEALTHY)
197 return CB_EFI_VS_CORRUPTED_INVALID;
198
199 if (rdev_chain(rdev, rdev, fv_hdr->HeaderLength + sizeof(hdr), hdr.Size)) {
200 printk(BIOS_WARNING, PREFIX "rdev_chain failed\n");
201 return CB_EFI_ACCESS_ERROR;
202 }
203
204 printk(BIOS_SPEW, PREFIX "UEFI variable store with size %zu found\n",
205 region_device_sz(rdev));
206
207 return CB_SUCCESS;
208 }
209
210 struct efi_find_args {
211 const EFI_GUID *guid;
212 const char *name;
213 uint32_t *size;
214 void *data;
215 };
216
match(struct region_device * rdev,VARIABLE_HEADER * hdr,size_t hdr_size,const char * name,const EFI_GUID * guid)217 static bool match(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
218 const char *name, const EFI_GUID *guid)
219 {
220 /* Only search for valid or in transition to be deleted variables */
221 if ((hdr->State != VAR_ADDED) &&
222 (hdr->State != (VAR_IN_DELETED_TRANSITION & VAR_ADDED)))
223 return false;
224
225 if ((!compare_guid(&hdr->VendorGuid, guid)) ||
226 !hdr->NameSize ||
227 !hdr->DataSize)
228 return false;
229
230 if (rdev_strcmp_wchar_ascii(rdev, hdr_size, name) != 0)
231 return false;
232
233 return true;
234 }
235
236 static
find_and_copy(struct region_device * rdev,VARIABLE_HEADER * hdr,size_t hdr_size,void * arg,bool * stop)237 enum cb_err find_and_copy(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
238 void *arg, bool *stop)
239 {
240 struct efi_find_args *fa = (struct efi_find_args *)arg;
241
242 if (!match(rdev, hdr, hdr_size, fa->name, fa->guid))
243 return CB_SUCCESS;
244
245 *stop = true;
246 if (*(fa->size) < hdr->DataSize)
247 return CB_EFI_BUFFER_TOO_SMALL;
248
249 if (rdev_readat(rdev, fa->data, hdr_size + hdr->NameSize, hdr->DataSize) !=
250 hdr->DataSize)
251 return CB_EFI_ACCESS_ERROR;
252
253 *(fa->size) = hdr->DataSize;
254 return CB_SUCCESS;
255 }
256
257 struct efi_find_compare_args {
258 const EFI_GUID *guid;
259 const char *name;
260 uint32_t size;
261 void *data;
262 bool match;
263 };
264
265 static
find_and_compare(struct region_device * rdev,VARIABLE_HEADER * hdr,size_t hdr_size,void * arg,bool * stop)266 enum cb_err find_and_compare(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
267 void *arg, bool *stop)
268 {
269 struct efi_find_compare_args *fa = (struct efi_find_compare_args *)arg;
270
271 if (!match(rdev, hdr, hdr_size, fa->name, fa->guid))
272 return CB_SUCCESS;
273
274 *stop = true;
275 if (fa->size != hdr->DataSize) {
276 fa->match = false;
277 return CB_SUCCESS;
278 }
279
280 fa->match = rdev_memcmp(rdev, hdr_size + hdr->NameSize, fa->data, hdr->DataSize) == 0;
281
282 return CB_SUCCESS;
283 }
284
noop(struct region_device * rdev,VARIABLE_HEADER * hdr,size_t hdr_size,void * arg,bool * stop)285 static enum cb_err noop(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
286 void *arg, bool *stop)
287 {
288 /* Does nothing. */
289 return CB_SUCCESS;
290 }
291
print_var(struct region_device * rdev,VARIABLE_HEADER * hdr,size_t hdr_size,void * arg,bool * stop)292 static enum cb_err print_var(struct region_device *rdev, VARIABLE_HEADER *hdr, size_t hdr_size,
293 void *arg, bool *stop)
294 {
295 uint8_t buf[16];
296 size_t len, i;
297
298 printk(BIOS_DEBUG, "%08zx: Var ", region_device_offset(rdev));
299 print_guid(BIOS_DEBUG, &hdr->VendorGuid);
300
301 printk(BIOS_DEBUG, "-");
302
303 rdev_print_wchar(BIOS_DEBUG, rdev, hdr_size);
304
305 printk(BIOS_DEBUG, ", State %02x, Size %02x\n", hdr->State, hdr->DataSize);
306
307 if (hdr->DataSize && hdr->NameSize) {
308 len = sizeof(buf) < hdr->DataSize ? sizeof(buf) : hdr->DataSize;
309 if (rdev_readat(rdev, buf, hdr_size + hdr->NameSize, len) != len)
310 return CB_EFI_ACCESS_ERROR;
311 printk(BIOS_DEBUG, " Data: ");
312
313 for (i = 0; i < len; i++)
314 printk(BIOS_DEBUG, "0x%02x ", buf[i]);
315
316 if (hdr->DataSize > len)
317 printk(BIOS_DEBUG, "...");
318
319 printk(BIOS_DEBUG, "\n");
320 }
321
322 return CB_SUCCESS;
323 }
324
walk_variables(struct region_device * rdev,bool auth_format,enum cb_err (* walker)(struct region_device * rdev,VARIABLE_HEADER * hdr,size_t hdr_size,void * arg,bool * stop),void * walker_arg)325 static enum cb_err walk_variables(struct region_device *rdev,
326 bool auth_format,
327 enum cb_err (*walker)(struct region_device *rdev,
328 VARIABLE_HEADER *hdr,
329 size_t hdr_size,
330 void *arg,
331 bool *stop),
332 void *walker_arg)
333 {
334 AUTHENTICATED_VARIABLE_HEADER auth_hdr;
335 size_t header_size, var_size;
336 VARIABLE_HEADER hdr;
337 bool stop;
338 enum cb_err ret;
339
340 if (auth_format)
341 header_size = sizeof(AUTHENTICATED_VARIABLE_HEADER);
342 else
343 header_size = sizeof(VARIABLE_HEADER);
344
345 do {
346 if (auth_format) {
347 if (rdev_readat(rdev, &auth_hdr, 0, sizeof(auth_hdr))
348 != sizeof(auth_hdr))
349 return CB_EFI_ACCESS_ERROR;
350 hdr.Reserved = auth_hdr.Reserved;
351 hdr.StartId = auth_hdr.StartId;
352 hdr.State = auth_hdr.State;
353 hdr.Attributes = auth_hdr.Attributes;
354 hdr.NameSize = auth_hdr.NameSize;
355 hdr.DataSize = auth_hdr.DataSize;
356 memcpy(&hdr.VendorGuid, &auth_hdr.VendorGuid, sizeof(hdr.VendorGuid));
357 } else if (rdev_readat(rdev, &hdr, 0, sizeof(hdr)) != sizeof(hdr)) {
358 return CB_EFI_ACCESS_ERROR;
359 }
360 if (hdr.StartId != VARIABLE_DATA)
361 break;
362
363 if (hdr.State == UINT8_MAX ||
364 hdr.DataSize == UINT32_MAX ||
365 hdr.NameSize == UINT32_MAX ||
366 hdr.Attributes == UINT32_MAX) {
367 hdr.NameSize = 0;
368 hdr.DataSize = 0;
369 }
370
371 printk(BIOS_SPEW, "Found variable with state %02x and ", hdr.State);
372 print_guid(BIOS_SPEW, &hdr.VendorGuid);
373 printk(BIOS_SPEW, "\n");
374
375 stop = false;
376
377 ret = walker(rdev, &hdr, header_size, walker_arg, &stop);
378
379 if (ret != CB_SUCCESS || stop)
380 return ret;
381
382 var_size = ALIGN_UP(header_size + hdr.NameSize + hdr.DataSize,
383 HEADER_ALIGNMENT);
384 } while (!rdev_chain(rdev, rdev, var_size, region_device_sz(rdev) - var_size));
385
386 return CB_EFI_OPTION_NOT_FOUND;
387 }
388
efi_fv_init(struct region_device * rdev,bool * auth_format)389 static enum cb_err efi_fv_init(struct region_device *rdev, bool *auth_format)
390 {
391 EFI_FIRMWARE_VOLUME_HEADER fv_hdr;
392 enum cb_err ret;
393
394 ret = validate_fv_header(rdev, &fv_hdr);
395 if (ret != CB_SUCCESS) {
396 printk(BIOS_WARNING, PREFIX "Failed to validate firmware header\n");
397
398 return ret;
399 }
400 ret = validate_variable_store_header(&fv_hdr, rdev, auth_format);
401 if (ret != CB_SUCCESS)
402 printk(BIOS_WARNING, PREFIX "Failed to validate variable store header\n");
403
404 return ret;
405 }
406
efi_fv_print_options(struct region_device * rdev)407 enum cb_err efi_fv_print_options(struct region_device *rdev)
408 {
409 enum cb_err ret;
410 bool auth_format;
411
412 ret = efi_fv_init(rdev, &auth_format);
413 if (ret != CB_SUCCESS)
414 return ret;
415
416 return walk_variables(rdev, auth_format, print_var, NULL);
417 }
418
419 /*
420 * efi_fv_get_option
421 * - writes up to *size bytes into a buffer pointed to by *dest
422 * - rdev is the spi flash region to operate on
423 * - the FVH and variable store header must have been initialized by a third party
424 */
efi_fv_get_option(struct region_device * rdev,const EFI_GUID * guid,const char * name,void * dest,uint32_t * size)425 enum cb_err efi_fv_get_option(struct region_device *rdev,
426 const EFI_GUID *guid,
427 const char *name,
428 void *dest,
429 uint32_t *size)
430 {
431 struct efi_find_args args;
432 bool auth_format;
433 enum cb_err ret;
434
435 ret = efi_fv_init(rdev, &auth_format);
436 if (ret != CB_SUCCESS)
437 return ret;
438
439 args.guid = guid;
440 args.name = name;
441 args.size = size;
442 args.data = dest;
443
444 return walk_variables(rdev, auth_format, find_and_copy, &args);
445 }
446
write_auth_hdr(struct region_device * rdev,const EFI_GUID * guid,const char * name,void * data,size_t size)447 static enum cb_err write_auth_hdr(struct region_device *rdev, const EFI_GUID *guid,
448 const char *name, void *data, size_t size)
449 {
450 AUTHENTICATED_VARIABLE_HEADER auth_hdr;
451 size_t name_size, var_size;
452 enum cb_err ret;
453
454 name_size = (strlen(name) + 1) * sizeof(CHAR16);
455 var_size = name_size + size + sizeof(auth_hdr);
456
457 if (var_size > region_device_sz(rdev))
458 return CB_EFI_STORE_FULL;
459
460 /* Sanity check. flash must be blank */
461 if (rdev_readat(rdev, &auth_hdr, 0, sizeof(auth_hdr)) != sizeof(auth_hdr))
462 return CB_EFI_ACCESS_ERROR;
463
464 if (auth_hdr.StartId != UINT16_MAX ||
465 auth_hdr.State != UINT8_MAX ||
466 auth_hdr.DataSize != UINT32_MAX ||
467 auth_hdr.NameSize != UINT32_MAX ||
468 auth_hdr.Attributes != UINT32_MAX) {
469 return CB_EFI_ACCESS_ERROR;
470 }
471
472 memset(&auth_hdr, 0xff, sizeof(auth_hdr));
473
474 auth_hdr.StartId = VARIABLE_DATA;
475 auth_hdr.Attributes = EFI_VARIABLE_NON_VOLATILE|
476 EFI_VARIABLE_BOOTSERVICE_ACCESS|
477 EFI_VARIABLE_RUNTIME_ACCESS;
478 auth_hdr.NameSize = name_size;
479 auth_hdr.DataSize = size;
480 memcpy(&auth_hdr.VendorGuid, guid, sizeof(EFI_GUID));
481
482 /* Write header with no State */
483 if (rdev_writeat(rdev, &auth_hdr, 0, sizeof(auth_hdr)) != sizeof(auth_hdr))
484 return CB_EFI_ACCESS_ERROR;
485
486 /* Set header State to valid header */
487 auth_hdr.State = VAR_HEADER_VALID_ONLY;
488 if (rdev_writeat(rdev, &auth_hdr.State, offsetof(AUTHENTICATED_VARIABLE_HEADER, State),
489 sizeof(auth_hdr.State)) != sizeof(auth_hdr.State))
490 return CB_EFI_ACCESS_ERROR;
491
492 /* Write the name */
493 ret = rdev_write_wchar(rdev, sizeof(auth_hdr), name);
494 if (ret != CB_SUCCESS)
495 return ret;
496
497 /* Write the data */
498 if (rdev_writeat(rdev, data, sizeof(auth_hdr) + name_size, size) != size)
499 return CB_EFI_ACCESS_ERROR;
500
501 /* Set header State to valid data */
502 auth_hdr.State = VAR_ADDED;
503 if (rdev_writeat(rdev, &auth_hdr.State, offsetof(AUTHENTICATED_VARIABLE_HEADER, State),
504 sizeof(auth_hdr.State)) != sizeof(auth_hdr.State))
505 return CB_EFI_ACCESS_ERROR;
506
507 return CB_SUCCESS;
508 }
509
write_hdr(struct region_device * rdev,const EFI_GUID * guid,const char * name,void * data,size_t size)510 static enum cb_err write_hdr(struct region_device *rdev, const EFI_GUID *guid,
511 const char *name,
512 void *data,
513 size_t size)
514 {
515 VARIABLE_HEADER hdr;
516 size_t name_size, var_size;
517 enum cb_err ret;
518
519 name_size = (strlen(name) + 1) * sizeof(CHAR16);
520 var_size = name_size + size + sizeof(hdr);
521 if (var_size > region_device_sz(rdev))
522 return CB_EFI_STORE_FULL;
523
524 /* Sanity check. flash must be blank */
525 if (rdev_readat(rdev, &hdr, 0, sizeof(hdr)) != sizeof(hdr))
526 return CB_EFI_ACCESS_ERROR;
527
528 if (hdr.StartId != UINT16_MAX ||
529 hdr.State != UINT8_MAX ||
530 hdr.DataSize != UINT32_MAX ||
531 hdr.NameSize != UINT32_MAX ||
532 hdr.Attributes != UINT32_MAX) {
533 return CB_EFI_ACCESS_ERROR;
534 }
535
536 memset(&hdr, 0xff, sizeof(hdr));
537
538 hdr.StartId = VARIABLE_DATA;
539 hdr.Attributes = EFI_VARIABLE_NON_VOLATILE|
540 EFI_VARIABLE_BOOTSERVICE_ACCESS|
541 EFI_VARIABLE_RUNTIME_ACCESS;
542 hdr.NameSize = name_size;
543 hdr.DataSize = size;
544 memcpy(&hdr.VendorGuid, guid, sizeof(EFI_GUID));
545
546 /* Write header with no State */
547 if (rdev_writeat(rdev, &hdr, 0, sizeof(hdr)) != sizeof(hdr))
548 return CB_EFI_ACCESS_ERROR;
549
550 /* Set header State to valid header */
551 hdr.State = VAR_HEADER_VALID_ONLY;
552 if (rdev_writeat(rdev, &hdr.State, offsetof(VARIABLE_HEADER, State),
553 sizeof(hdr.State)) != sizeof(hdr.State))
554 return CB_EFI_ACCESS_ERROR;
555
556 /* Write the name */
557 ret = rdev_write_wchar(rdev, sizeof(hdr), name);
558 if (ret != CB_SUCCESS)
559 return ret;
560
561 /* Write the data */
562 if (rdev_writeat(rdev, data, sizeof(hdr) + name_size, size) != size)
563 return CB_EFI_ACCESS_ERROR;
564
565 /* Set header State to valid data */
566 hdr.State = VAR_ADDED;
567 if (rdev_writeat(rdev, &hdr.State, offsetof(VARIABLE_HEADER, State),
568 sizeof(hdr.State)) != sizeof(hdr.State))
569 return CB_EFI_ACCESS_ERROR;
570
571 return CB_SUCCESS;
572 }
573
574 /*
575 * efi_fv_set_option
576 * - writes size bytes read from the buffer pointed to by *data
577 * - rdev is the spi flash region to operate on
578 * - the FVH and variable store header must have been initialized by a third party
579 */
efi_fv_set_option(struct region_device * rdev,const EFI_GUID * guid,const char * name,void * data,uint32_t size)580 enum cb_err efi_fv_set_option(struct region_device *rdev,
581 const EFI_GUID *guid,
582 const char *name,
583 void *data,
584 uint32_t size)
585 {
586 struct region_device rdev_old;
587 struct efi_find_compare_args args;
588 bool found_existing;
589 VARIABLE_HEADER hdr;
590 bool auth_format;
591 enum cb_err ret;
592
593 ret = efi_fv_init(rdev, &auth_format);
594 if (ret != CB_SUCCESS)
595 return ret;
596
597 /* Find existing variable */
598 args.guid = guid;
599 args.name = name;
600 args.size = size;
601 args.match = false;
602 args.data = data;
603
604 ret = walk_variables(rdev, auth_format, find_and_compare, &args);
605 found_existing = ret == CB_SUCCESS;
606
607 if (found_existing) {
608 printk(BIOS_ERR, "found existing variable %s, match =%d\n", name, args.match);
609
610 if (args.match)
611 return CB_SUCCESS;
612
613 rdev_old = *rdev;
614
615 /* Mark as to be deleted */
616 hdr.State = VAR_IN_DELETED_TRANSITION;
617 if (rdev_writeat(rdev, &hdr.State, offsetof(VARIABLE_HEADER, State),
618 sizeof(hdr.State)) != sizeof(hdr.State))
619 return CB_EFI_ACCESS_ERROR;
620 }
621
622 /* Walk to end of variable store */
623 ret = walk_variables(rdev, auth_format, noop, NULL);
624 if (ret != CB_EFI_OPTION_NOT_FOUND)
625 return ret;
626
627 /* Now append new variable:
628 * 1. Write the header without State field.
629 * 2. Write the State field and set it to HEADER_VALID.
630 * 3. Write data
631 * 4. Write the State field and set it to VAR_ADDED
632 */
633
634 if (auth_format)
635 ret = write_auth_hdr(rdev, guid, name, data, size);
636 else
637 ret = write_hdr(rdev, guid, name, data, size);
638 if (ret != CB_SUCCESS)
639 return ret;
640
641 if (found_existing) {
642 /* Mark old variable as deleted */
643 hdr.State = VAR_DELETED;
644 if (rdev_writeat(&rdev_old, &hdr.State, offsetof(VARIABLE_HEADER, State),
645 sizeof(hdr.State)) != sizeof(hdr.State))
646 return CB_EFI_ACCESS_ERROR;
647 }
648
649 return CB_SUCCESS;
650 }
651