src/shared/efivars.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2013 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <dirent.h>
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <limits.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <sys/stat.h>
  28 #include <unistd.h>
  29
  30 #include "sd-id128.h"
  31
  32 #include "alloc-util.h"
  33 #include "dirent-util.h"
  34 #include "efivars.h"
  35 #include "fd-util.h"
  36 #include "io-util.h"
  37 #include "macro.h"
  38 #include "parse-util.h"
  39 #include "stdio-util.h"
  40 #include "time-util.h"
  41 #include "utf8.h"
  42 #include "util.h"
  43 #include "virt.h"
  44
  45 #ifdef ENABLE_EFI
  46
  47 #define LOAD_OPTION_ACTIVE            0x00000001
  48 #define MEDIA_DEVICE_PATH                   0x04
  49 #define MEDIA_HARDDRIVE_DP                  0x01
  50 #define MEDIA_FILEPATH_DP                   0x04
  51 #define SIGNATURE_TYPE_GUID                 0x02
  52 #define MBR_TYPE_EFI_PARTITION_TABLE_HEADER 0x02
  53 #define END_DEVICE_PATH_TYPE                0x7f
  54 #define END_ENTIRE_DEVICE_PATH_SUBTYPE      0xff
  55 #define EFI_OS_INDICATIONS_BOOT_TO_FW_UI    0x0000000000000001
  56
  57 struct boot_option {
  58         uint32_t attr;
  59         uint16_t path_len;
  60         uint16_t title[];
  61 } _packed_;
  62
  63 struct drive_path {
  64         uint32_t part_nr;
  65         uint64_t part_start;
  66         uint64_t part_size;
  67         char signature[16];
  68         uint8_t mbr_type;
  69         uint8_t signature_type;
  70 } _packed_;
  71
  72 struct device_path {
  73         uint8_t type;
  74         uint8_t sub_type;
  75         uint16_t length;
  76         union {
  77                 uint16_t path[0];
  78                 struct drive_path drive;
  79         };
  80 } _packed_;
  81
  82 bool is_efi_boot(void) {
  83         return access("/sys/firmware/efi", F_OK) >= 0;
  84 }
  85
  86 static int read_flag(const char *varname) {
  87         int r;
  88         _cleanup_free_ void *v = NULL;
  89         size_t s;
  90         uint8_t b;
  91
  92         r = efi_get_variable(EFI_VENDOR_GLOBAL, varname, NULL, &v, &s);
  93         if (r < 0)
  94                 return r;
  95
  96         if (s != 1)
  97                 return -EINVAL;
  98
  99         b = *(uint8_t *)v;
 100         r = b > 0;
 101         return r;
 102 }
 103
 104 bool is_efi_secure_boot(void) {
 105         return read_flag("SecureBoot") > 0;
 106 }
 107
 108 bool is_efi_secure_boot_setup_mode(void) {
 109         return read_flag("SetupMode") > 0;
 110 }
 111
 112 int efi_reboot_to_firmware_supported(void) {
 113         int r;
 114         size_t s;
 115         uint64_t b;
 116         _cleanup_free_ void *v = NULL;
 117
 118         if (!is_efi_boot() || detect_container() > 0)
 119                 return -EOPNOTSUPP;
 120
 121         r = efi_get_variable(EFI_VENDOR_GLOBAL, "OsIndicationsSupported", NULL, &v, &s);
 122         if (r < 0)
 123                 return r;
 124         else if (s != sizeof(uint64_t))
 125                 return -EINVAL;
 126
 127         b = *(uint64_t *)v;
 128         b &= EFI_OS_INDICATIONS_BOOT_TO_FW_UI;
 129         return b > 0 ? 0 : -EOPNOTSUPP;
 130 }
 131
 132 static int get_os_indications(uint64_t *os_indication) {
 133         int r;
 134         size_t s;
 135         _cleanup_free_ void *v = NULL;
 136
 137         r = efi_reboot_to_firmware_supported();
 138         if (r < 0)
 139                 return r;
 140
 141         r = efi_get_variable(EFI_VENDOR_GLOBAL, "OsIndications", NULL, &v, &s);
 142         if (r == -ENOENT) {
 143                 /* Some firmware implementations that do support
 144                  * OsIndications and report that with
 145                  * OsIndicationsSupported will remove the
 146                  * OsIndications variable when it is unset. Let's
 147                  * pretend it's 0 then, to hide this implementation
 148                  * detail. Note that this call will return -ENOENT
 149                  * then only if the support for OsIndications is
 150                  * missing entirely, as determined by
 151                  * efi_reboot_to_firmware_supported() above. */
 152                 *os_indication = 0;
 153                 return 0;
 154         } else if (r < 0)
 155                 return r;
 156         else if (s != sizeof(uint64_t))
 157                 return -EINVAL;
 158
 159         *os_indication = *(uint64_t *)v;
 160         return 0;
 161 }
 162
 163 int efi_get_reboot_to_firmware(void) {
 164         int r;
 165         uint64_t b;
 166
 167         r = get_os_indications(&b);
 168         if (r < 0)
 169                 return r;
 170
 171         return !!(b & EFI_OS_INDICATIONS_BOOT_TO_FW_UI);
 172 }
 173
 174 int efi_set_reboot_to_firmware(bool value) {
 175         int r;
 176         uint64_t b, b_new;
 177
 178         r = get_os_indications(&b);
 179         if (r < 0)
 180                 return r;
 181
 182         if (value)
 183                 b_new = b | EFI_OS_INDICATIONS_BOOT_TO_FW_UI;
 184         else
 185                 b_new = b & ~EFI_OS_INDICATIONS_BOOT_TO_FW_UI;
 186
 187         /* Avoid writing to efi vars store if we can due to firmware bugs. */
 188         if (b != b_new)
 189                 return efi_set_variable(EFI_VENDOR_GLOBAL, "OsIndications", &b_new, sizeof(uint64_t));
 190
 191         return 0;
 192 }
 193
 194 int efi_get_variable(
 195                 sd_id128_t vendor,
 196                 const char *name,
 197                 uint32_t *attribute,
 198                 void **value,
 199                 size_t *size) {
 200
 201         _cleanup_close_ int fd = -1;
 202         _cleanup_free_ char *p = NULL;
 203         uint32_t a;
 204         ssize_t n;
 205         struct stat st;
 206         _cleanup_free_ void *buf = NULL;
 207
 208         assert(name);
 209         assert(value);
 210         assert(size);
 211
 212         if (asprintf(&p,
 213                      "/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 214                      name, SD_ID128_FORMAT_VAL(vendor)) < 0)
 215                 return -ENOMEM;
 216
 217         fd = open(p, O_RDONLY|O_NOCTTY|O_CLOEXEC);
 218         if (fd < 0)
 219                 return -errno;
 220
 221         if (fstat(fd, &st) < 0)
 222                 return -errno;
 223         if (st.st_size < 4)
 224                 return -EIO;
 225         if (st.st_size > 4*1024*1024 + 4)
 226                 return -E2BIG;
 227
 228         n = read(fd, &a, sizeof(a));
 229         if (n < 0)
 230                 return -errno;
 231         if (n != sizeof(a))
 232                 return -EIO;
 233
 234         buf = malloc(st.st_size - 4 + 2);
 235         if (!buf)
 236                 return -ENOMEM;
 237
 238         n = read(fd, buf, (size_t) st.st_size - 4);
 239         if (n < 0)
 240                 return -errno;
 241         if (n != (ssize_t) st.st_size - 4)
 242                 return -EIO;
 243
 244         /* Always NUL terminate (2 bytes, to protect UTF-16) */
 245         ((char*) buf)[st.st_size - 4] = 0;
 246         ((char*) buf)[st.st_size - 4 + 1] = 0;
 247
 248         *value = buf;
 249         buf = NULL;
 250         *size = (size_t) st.st_size - 4;
 251
 252         if (attribute)
 253                 *attribute = a;
 254
 255         return 0;
 256 }
 257
 258 int efi_set_variable(
 259                 sd_id128_t vendor,
 260                 const char *name,
 261                 const void *value,
 262                 size_t size) {
 263
 264         struct var {
 265                 uint32_t attr;
 266                 char buf[];
 267         } _packed_ * _cleanup_free_ buf = NULL;
 268         _cleanup_free_ char *p = NULL;
 269         _cleanup_close_ int fd = -1;
 270
 271         assert(name);
 272         assert(value || size == 0);
 273
 274         if (asprintf(&p,
 275                      "/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 276                      name, SD_ID128_FORMAT_VAL(vendor)) < 0)
 277                 return -ENOMEM;
 278
 279         if (size == 0) {
 280                 if (unlink(p) < 0)
 281                         return -errno;
 282                 return 0;
 283         }
 284
 285         fd = open(p, O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC, 0644);
 286         if (fd < 0)
 287                 return -errno;
 288
 289         buf = malloc(sizeof(uint32_t) + size);
 290         if (!buf)
 291                 return -ENOMEM;
 292
 293         buf->attr = EFI_VARIABLE_NON_VOLATILE|EFI_VARIABLE_BOOTSERVICE_ACCESS|EFI_VARIABLE_RUNTIME_ACCESS;
 294         memcpy(buf->buf, value, size);
 295
 296         return loop_write(fd, buf, sizeof(uint32_t) + size, false);
 297 }
 298
 299 int efi_get_variable_string(sd_id128_t vendor, const char *name, char **p) {
 300         _cleanup_free_ void *s = NULL;
 301         size_t ss = 0;
 302         int r;
 303         char *x;
 304
 305         r = efi_get_variable(vendor, name, NULL, &s, &ss);
 306         if (r < 0)
 307                 return r;
 308
 309         x = utf16_to_utf8(s, ss);
 310         if (!x)
 311                 return -ENOMEM;
 312
 313         *p = x;
 314         return 0;
 315 }
 316
 317 static size_t utf16_size(const uint16_t *s) {
 318         size_t l = 0;
 319
 320         while (s[l] > 0)
 321                 l++;
 322
 323         return (l+1) * sizeof(uint16_t);
 324 }
 325
 326 static void efi_guid_to_id128(const void *guid, sd_id128_t *id128) {
 327         struct uuid {
 328                 uint32_t u1;
 329                 uint16_t u2;
 330                 uint16_t u3;
 331                 uint8_t u4[8];
 332         } _packed_;
 333         const struct uuid *uuid = guid;
 334
 335         id128->bytes[0] = (uuid->u1 >> 24) & 0xff;
 336         id128->bytes[1] = (uuid->u1 >> 16) & 0xff;
 337         id128->bytes[2] = (uuid->u1 >> 8) & 0xff;
 338         id128->bytes[3] = (uuid->u1) & 0xff;
 339         id128->bytes[4] = (uuid->u2 >> 8) & 0xff;
 340         id128->bytes[5] = (uuid->u2) & 0xff;
 341         id128->bytes[6] = (uuid->u3 >> 8) & 0xff;
 342         id128->bytes[7] = (uuid->u3) & 0xff;
 343         memcpy(&id128->bytes[8], uuid->u4, sizeof(uuid->u4));
 344 }
 345
 346 int efi_get_boot_option(
 347                 uint16_t id,
 348                 char **title,
 349                 sd_id128_t *part_uuid,
 350                 char **path,
 351                 bool *active) {
 352
 353         char boot_id[9];
 354         _cleanup_free_ uint8_t *buf = NULL;
 355         size_t l;
 356         struct boot_option *header;
 357         size_t title_size;
 358         _cleanup_free_ char *s = NULL, *p = NULL;
 359         sd_id128_t p_uuid = SD_ID128_NULL;
 360         int r;
 361
 362         xsprintf(boot_id, "Boot%04X", id);
 363         r = efi_get_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, (void **)&buf, &l);
 364         if (r < 0)
 365                 return r;
 366         if (l < sizeof(struct boot_option))
 367                 return -ENOENT;
 368
 369         header = (struct boot_option *)buf;
 370         title_size = utf16_size(header->title);
 371         if (title_size > l - offsetof(struct boot_option, title))
 372                 return -EINVAL;
 373
 374         if (title) {
 375                 s = utf16_to_utf8(header->title, title_size);
 376                 if (!s)
 377                         return -ENOMEM;
 378         }
 379
 380         if (header->path_len > 0) {
 381                 uint8_t *dbuf;
 382                 size_t dnext;
 383
 384                 dbuf = buf + offsetof(struct boot_option, title) + title_size;
 385                 dnext = 0;
 386                 while (dnext < header->path_len) {
 387                         struct device_path *dpath;
 388
 389                         dpath = (struct device_path *)(dbuf + dnext);
 390                         if (dpath->length < 4)
 391                                 break;
 392
 393                         /* Type 0x7F – End of Hardware Device Path, Sub-Type 0xFF – End Entire Device Path */
 394                         if (dpath->type == END_DEVICE_PATH_TYPE && dpath->sub_type == END_ENTIRE_DEVICE_PATH_SUBTYPE)
 395                                 break;
 396
 397                         dnext += dpath->length;
 398
 399                         /* Type 0x04 – Media Device Path */
 400                         if (dpath->type != MEDIA_DEVICE_PATH)
 401                                 continue;
 402
 403                         /* Sub-Type 1 – Hard Drive */
 404                         if (dpath->sub_type == MEDIA_HARDDRIVE_DP) {
 405                                 /* 0x02 – GUID Partition Table */
 406                                 if (dpath->drive.mbr_type != MBR_TYPE_EFI_PARTITION_TABLE_HEADER)
 407                                         continue;
 408
 409                                 /* 0x02 – GUID signature */
 410                                 if (dpath->drive.signature_type != SIGNATURE_TYPE_GUID)
 411                                         continue;
 412
 413                                 if (part_uuid)
 414                                         efi_guid_to_id128(dpath->drive.signature, &p_uuid);
 415                                 continue;
 416                         }
 417
 418                         /* Sub-Type 4 – File Path */
 419                         if (dpath->sub_type == MEDIA_FILEPATH_DP && !p && path) {
 420                                 p = utf16_to_utf8(dpath->path, dpath->length-4);
 421                                 efi_tilt_backslashes(p);
 422                                 continue;
 423                         }
 424                 }
 425         }
 426
 427         if (title) {
 428                 *title = s;
 429                 s = NULL;
 430         }
 431         if (part_uuid)
 432                 *part_uuid = p_uuid;
 433         if (path) {
 434                 *path = p;
 435                 p = NULL;
 436         }
 437         if (active)
 438                 *active = !!(header->attr & LOAD_OPTION_ACTIVE);
 439
 440         return 0;
 441 }
 442
 443 static void to_utf16(uint16_t *dest, const char *src) {
 444         int i;
 445
 446         for (i = 0; src[i] != '\0'; i++)
 447                 dest[i] = src[i];
 448         dest[i] = '\0';
 449 }
 450
 451 struct guid {
 452         uint32_t u1;
 453         uint16_t u2;
 454         uint16_t u3;
 455         uint8_t u4[8];
 456 } _packed_;
 457
 458 static void id128_to_efi_guid(sd_id128_t id, void *guid) {
 459         struct guid *uuid = guid;
 460
 461         uuid->u1 = id.bytes[0] << 24 | id.bytes[1] << 16 | id.bytes[2] << 8 | id.bytes[3];
 462         uuid->u2 = id.bytes[4] << 8 | id.bytes[5];
 463         uuid->u3 = id.bytes[6] << 8 | id.bytes[7];
 464         memcpy(uuid->u4, id.bytes+8, sizeof(uuid->u4));
 465 }
 466
 467 static uint16_t *tilt_slashes(uint16_t *s) {
 468         uint16_t *p;
 469
 470         for (p = s; *p; p++)
 471                 if (*p == '/')
 472                         *p = '\\';
 473
 474         return s;
 475 }
 476
 477 int efi_add_boot_option(uint16_t id, const char *title,
 478                         uint32_t part, uint64_t pstart, uint64_t psize,
 479                         sd_id128_t part_uuid, const char *path) {
 480         char boot_id[9];
 481         size_t size;
 482         size_t title_len;
 483         size_t path_len;
 484         struct boot_option *option;
 485         struct device_path *devicep;
 486         _cleanup_free_ char *buf = NULL;
 487
 488         title_len = (strlen(title)+1) * 2;
 489         path_len = (strlen(path)+1) * 2;
 490
 491         buf = calloc(sizeof(struct boot_option) + title_len +
 492                      sizeof(struct drive_path) +
 493                      sizeof(struct device_path) + path_len, 1);
 494         if (!buf)
 495                 return -ENOMEM;
 496
 497         /* header */
 498         option = (struct boot_option *)buf;
 499         option->attr = LOAD_OPTION_ACTIVE;
 500         option->path_len = offsetof(struct device_path, drive) + sizeof(struct drive_path) +
 501                            offsetof(struct device_path, path) + path_len +
 502                            offsetof(struct device_path, path);
 503         to_utf16(option->title, title);
 504         size = offsetof(struct boot_option, title) + title_len;
 505
 506         /* partition info */
 507         devicep = (struct device_path *)(buf + size);
 508         devicep->type = MEDIA_DEVICE_PATH;
 509         devicep->sub_type = MEDIA_HARDDRIVE_DP;
 510         devicep->length = offsetof(struct device_path, drive) + sizeof(struct drive_path);
 511         devicep->drive.part_nr = part;
 512         devicep->drive.part_start = pstart;
 513         devicep->drive.part_size = psize;
 514         devicep->drive.signature_type = SIGNATURE_TYPE_GUID;
 515         devicep->drive.mbr_type = MBR_TYPE_EFI_PARTITION_TABLE_HEADER;
 516         id128_to_efi_guid(part_uuid, devicep->drive.signature);
 517         size += devicep->length;
 518
 519         /* path to loader */
 520         devicep = (struct device_path *)(buf + size);
 521         devicep->type = MEDIA_DEVICE_PATH;
 522         devicep->sub_type = MEDIA_FILEPATH_DP;
 523         devicep->length = offsetof(struct device_path, path) + path_len;
 524         to_utf16(devicep->path, path);
 525         tilt_slashes(devicep->path);
 526         size += devicep->length;
 527
 528         /* end of path */
 529         devicep = (struct device_path *)(buf + size);
 530         devicep->type = END_DEVICE_PATH_TYPE;
 531         devicep->sub_type = END_ENTIRE_DEVICE_PATH_SUBTYPE;
 532         devicep->length = offsetof(struct device_path, path);
 533         size += devicep->length;
 534
 535         xsprintf(boot_id, "Boot%04X", id);
 536         return efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, buf, size);
 537 }
 538
 539 int efi_remove_boot_option(uint16_t id) {
 540         char boot_id[9];
 541
 542         xsprintf(boot_id, "Boot%04X", id);
 543         return efi_set_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, 0);
 544 }
 545
 546 int efi_get_boot_order(uint16_t **order) {
 547         _cleanup_free_ void *buf = NULL;
 548         size_t l;
 549         int r;
 550
 551         r = efi_get_variable(EFI_VENDOR_GLOBAL, "BootOrder", NULL, &buf, &l);
 552         if (r < 0)
 553                 return r;
 554
 555         if (l <= 0)
 556                 return -ENOENT;
 557
 558         if (l % sizeof(uint16_t) > 0 ||
 559             l / sizeof(uint16_t) > INT_MAX)
 560                 return -EINVAL;
 561
 562         *order = buf;
 563         buf = NULL;
 564         return (int) (l / sizeof(uint16_t));
 565 }
 566
 567 int efi_set_boot_order(uint16_t *order, size_t n) {
 568         return efi_set_variable(EFI_VENDOR_GLOBAL, "BootOrder", order, n * sizeof(uint16_t));
 569 }
 570
 571 static int boot_id_hex(const char s[4]) {
 572         int i;
 573         int id = 0;
 574
 575         for (i = 0; i < 4; i++)
 576                 if (s[i] >= '0' && s[i] <= '9')
 577                         id |= (s[i] - '0') << (3 - i) * 4;
 578                 else if (s[i] >= 'A' && s[i] <= 'F')
 579                         id |= (s[i] - 'A' + 10) << (3 - i) * 4;
 580                 else
 581                         return -EINVAL;
 582
 583         return id;
 584 }
 585
 586 static int cmp_uint16(const void *_a, const void *_b) {
 587         const uint16_t *a = _a, *b = _b;
 588
 589         return (int)*a - (int)*b;
 590 }
 591
 592 int efi_get_boot_options(uint16_t **options) {
 593         _cleanup_closedir_ DIR *dir = NULL;
 594         struct dirent *de;
 595         _cleanup_free_ uint16_t *list = NULL;
 596         size_t alloc = 0;
 597         int count = 0;
 598
 599         assert(options);
 600
 601         dir = opendir("/sys/firmware/efi/efivars/");
 602         if (!dir)
 603                 return -errno;
 604
 605         FOREACH_DIRENT(de, dir, return -errno) {
 606                 int id;
 607
 608                 if (strncmp(de->d_name, "Boot", 4) != 0)
 609                         continue;
 610
 611                 if (strlen(de->d_name) != 45)
 612                         continue;
 613
 614                 if (strcmp(de->d_name + 8, "-8be4df61-93ca-11d2-aa0d-00e098032b8c") != 0)
 615                         continue;
 616
 617                 id = boot_id_hex(de->d_name + 4);
 618                 if (id < 0)
 619                         continue;
 620
 621                 if (!GREEDY_REALLOC(list, alloc, count + 1))
 622                         return -ENOMEM;
 623
 624                 list[count++] = id;
 625         }
 626
 627         qsort_safe(list, count, sizeof(uint16_t), cmp_uint16);
 628
 629         *options = list;
 630         list = NULL;
 631         return count;
 632 }
 633
 634 static int read_usec(sd_id128_t vendor, const char *name, usec_t *u) {
 635         _cleanup_free_ char *j = NULL;
 636         int r;
 637         uint64_t x = 0;
 638
 639         assert(name);
 640         assert(u);
 641
 642         r = efi_get_variable_string(EFI_VENDOR_LOADER, name, &j);
 643         if (r < 0)
 644                 return r;
 645
 646         r = safe_atou64(j, &x);
 647         if (r < 0)
 648                 return r;
 649
 650         *u = x;
 651         return 0;
 652 }
 653
 654 int efi_loader_get_boot_usec(usec_t *firmware, usec_t *loader) {
 655         uint64_t x, y;
 656         int r;
 657
 658         assert(firmware);
 659         assert(loader);
 660
 661         r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeInitUSec", &x);
 662         if (r < 0)
 663                 return r;
 664
 665         r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeExecUSec", &y);
 666         if (r < 0)
 667                 return r;
 668
 669         if (y == 0 || y < x)
 670                 return -EIO;
 671
 672         if (y > USEC_PER_HOUR)
 673                 return -EIO;
 674
 675         *firmware = x;
 676         *loader = y;
 677
 678         return 0;
 679 }
 680
 681 int efi_loader_get_device_part_uuid(sd_id128_t *u) {
 682         _cleanup_free_ char *p = NULL;
 683         int r, parsed[16];
 684
 685         r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderDevicePartUUID", &p);
 686         if (r < 0)
 687                 return r;
 688
 689         if (sscanf(p, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
 690                    &parsed[0], &parsed[1], &parsed[2], &parsed[3],
 691                    &parsed[4], &parsed[5], &parsed[6], &parsed[7],
 692                    &parsed[8], &parsed[9], &parsed[10], &parsed[11],
 693                    &parsed[12], &parsed[13], &parsed[14], &parsed[15]) != 16)
 694                 return -EIO;
 695
 696         if (u) {
 697                 unsigned i;
 698
 699                 for (i = 0; i < ELEMENTSOF(parsed); i++)
 700                         u->bytes[i] = parsed[i];
 701         }
 702
 703         return 0;
 704 }
 705
 706 #endif
 707
 708 char *efi_tilt_backslashes(char *s) {
 709         char *p;
 710
 711         for (p = s; *p; p++)
 712                 if (*p == '\\')
 713                         *p = '/';
 714
 715         return s;
 716 }