src/shared/efivars.c

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