dos/syslinux.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 1998-2008 H. Peter Anvin - All Rights Reserved
   4  *   Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
   5  *
   6  *   This program is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU General Public License as published by
   8  *   the Free Software Foundation, Inc., 53 Temple Place Ste 330,
   9  *   Boston MA 02111-1307, USA; either version 2 of the License, or
  10  *   (at your option) any later version; incorporated herein by reference.
  11  *
  12  * ----------------------------------------------------------------------- */
  13
  14 /*
  15  * syslinux.c - Linux installer program for SYSLINUX
  16  *
  17  * Hacked up for DOS.
  18  */
  19
  20 #include <errno.h>
  21 #include <getopt.h>
  22 #include <stdio.h>
  23 #include <string.h>
  24 #include <stdlib.h>
  25 #include <stdarg.h>
  26 #include "mystuff.h"
  27
  28 #include "syslinux.h"
  29 #include "libfat.h"
  30 #include "setadv.h"
  31 #include "sysexits.h"
  32 #include "syslxopt.h"
  33 #include "syslxint.h"
  34
  35 char *program = "syslinux.com";         /* Name of program */
  36 uint16_t dos_version;
  37
  38 #ifdef DEBUG
  39 # define dprintf printf
  40 void pause(void)
  41 {
  42     uint16_t ax;
  43
  44     asm volatile("int $0x16" : "=a" (ax) : "a" (0));
  45 }
  46 #else
  47 # define dprintf(...) ((void)0)
  48 # define pause() ((void)0)
  49 #endif
  50
  51 void unlock_device(int);
  52
  53 void __attribute__ ((noreturn)) die(const char *msg)
  54 {
  55     unlock_device(0);
  56     puts("syslinux: ");
  57     puts(msg);
  58     putchar('\n');
  59     exit(1);
  60 }
  61
  62 void warning(const char *msg)
  63 {
  64     puts("syslinux: warning: ");
  65     puts(msg);
  66     putchar('\n');
  67 }
  68
  69 /*
  70  * read/write wrapper functions
  71  */
  72 int creat(const char *filename, int mode)
  73 {
  74     uint16_t rv;
  75     uint8_t err;
  76
  77     dprintf("creat(\"%s\", 0x%x)\n", filename, mode);
  78
  79     rv = 0x3C00;
  80     asm volatile ("int $0x21 ; setc %0"
  81                   : "=bcdm" (err), "+a" (rv)
  82                   : "c" (mode), "d" (filename));
  83     if (err) {
  84         dprintf("rv = %d\n", rv);
  85         die("cannot open ldlinux.sys");
  86     }
  87
  88     return rv;
  89 }
  90
  91 void close(int fd)
  92 {
  93     uint16_t rv = 0x3E00;
  94
  95     dprintf("close(%d)\n", fd);
  96
  97     asm volatile ("int $0x21":"+a" (rv)
  98                   :"b"(fd));
  99
 100     /* The only error MS-DOS returns for close is EBADF,
 101        and we really don't care... */
 102 }
 103
 104 int rename(const char *oldname, const char *newname)
 105 {
 106     uint16_t rv = 0x5600;       /* Also support 43FFh? */
 107     uint8_t err;
 108
 109     dprintf("rename(\"%s\", \"%s\")\n", oldname, newname);
 110
 111     asm volatile ("int $0x21 ; setc %0":"=bcdm" (err), "+a"(rv)
 112                   :"d"(oldname), "D"(newname));
 113
 114     if (err) {
 115         dprintf("rv = %d\n", rv);
 116         warning("cannot move ldlinux.sys");
 117         return rv;
 118     }
 119
 120     return 0;
 121 }
 122
 123 ssize_t write_ldlinux(int fd)
 124 {
 125     uint16_t ldlinux_seg = ((size_t)syslinux_ldlinux >> 4) + ds();
 126     uint32_t offset = 0;
 127     uint16_t rv;
 128     uint8_t err;
 129
 130     while (offset < syslinux_ldlinux_len) {
 131         uint32_t chunk = syslinux_ldlinux_len - offset;
 132         if (chunk > 32768)
 133             chunk = 32768;
 134         asm volatile ("pushw %%ds ; "
 135                       "movw %6,%%ds ; "
 136                       "int $0x21 ; "
 137                       "popw %%ds ; " "setc %0":"=bcdm" (err), "=a"(rv)
 138                       :"a"(0x4000), "b"(fd), "c"(chunk), "d" (offset & 15),
 139                       "SD" ((uint16_t)(ldlinux_seg + (offset >> 4))));
 140         if (err || rv == 0)
 141             die("file write error");
 142         offset += rv;
 143     }
 144
 145     return offset;
 146 }
 147
 148 ssize_t write_file(int fd, const void *buf, size_t count)
 149 {
 150     uint16_t rv;
 151     ssize_t done = 0;
 152     uint8_t err;
 153
 154     dprintf("write_file(%d,%p,%u)\n", fd, buf, count);
 155
 156     while (count) {
 157         asm volatile ("int $0x21 ; setc %0":"=bcdm" (err), "=a"(rv)
 158                       :"a"(0x4000), "b"(fd), "c"(count), "d"(buf));
 159         if (err || rv == 0)
 160             die("file write error");
 161
 162         done += rv;
 163         count -= rv;
 164     }
 165
 166     return done;
 167 }
 168
 169 static inline __attribute__ ((const))
 170 uint16_t data_segment(void)
 171 {
 172     uint16_t ds;
 173
 174     asm("movw %%ds,%0" : "=rm"(ds));
 175     return ds;
 176 }
 177
 178 void write_device(int drive, const void *buf, size_t nsecs, unsigned int sector)
 179 {
 180     uint16_t errnum = 0x0001;
 181     struct diskio dio;
 182
 183     dprintf("write_device(%d,%p,%u,%u)\n", drive, buf, nsecs, sector);
 184
 185     dio.startsector = sector;
 186     dio.sectors = nsecs;
 187     dio.bufoffs = (uintptr_t) buf;
 188     dio.bufseg = data_segment();
 189
 190     if (dos_version >= 0x070a) {
 191         /* Try FAT32-aware system call first */
 192         asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
 193                      "1:"
 194                      : "=a" (errnum)
 195                      : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
 196                        "S" (1), "m" (dio)
 197                      : "memory");
 198         dprintf(" rv(7305) = %04x", errnum);
 199     }
 200
 201     /* If not supported, try the legacy system call (int2526.S) */
 202     if (errnum == 0x0001)
 203         errnum = int26_write_sector(drive, &dio);
 204
 205     if (errnum) {
 206         dprintf("rv = %04x\n", errnum);
 207         die("sector write error");
 208     }
 209 }
 210
 211 void read_device(int drive, void *buf, size_t nsecs, unsigned int sector)
 212 {
 213     uint16_t errnum = 0x0001;
 214     struct diskio dio;
 215
 216     dprintf("read_device(%d,%p,%u,%u)\n", drive, buf, nsecs, sector);
 217
 218     dio.startsector = sector;
 219     dio.sectors = nsecs;
 220     dio.bufoffs = (uintptr_t) buf;
 221     dio.bufseg = data_segment();
 222
 223     if (dos_version >= 0x070a) {
 224         /* Try FAT32-aware system call first */
 225         asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
 226                      "1:"
 227                      : "=a" (errnum)
 228                      : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
 229                        "S" (0), "m" (dio));
 230         dprintf(" rv(7305) = %04x", errnum);
 231     }
 232
 233     /* If not supported, try the legacy system call (int2526.S) */
 234     if (errnum == 0x0001)
 235         errnum = int25_read_sector(drive, &dio);
 236
 237     if (errnum) {
 238         dprintf("rv = %04x\n", errnum);
 239         die("sector read error");
 240     }
 241 }
 242
 243 /* Both traditional DOS and FAT32 DOS return this structure, but
 244    FAT32 return a lot more data, so make sure we have plenty of space */
 245 struct deviceparams {
 246     uint8_t specfunc;
 247     uint8_t devtype;
 248     uint16_t devattr;
 249     uint16_t cylinders;
 250     uint8_t mediatype;
 251     uint16_t bytespersec;
 252     uint8_t secperclust;
 253     uint16_t ressectors;
 254     uint8_t fats;
 255     uint16_t rootdirents;
 256     uint16_t sectors;
 257     uint8_t media;
 258     uint16_t fatsecs;
 259     uint16_t secpertrack;
 260     uint16_t heads;
 261     uint32_t hiddensecs;
 262     uint32_t hugesectors;
 263     uint8_t lotsofpadding[224];
 264 } __attribute__ ((packed));
 265
 266 uint32_t get_partition_offset(int drive)
 267 {
 268     uint8_t err;
 269     uint16_t rv;
 270     struct deviceparams dp;
 271
 272     dp.specfunc = 1;            /* Get current information */
 273
 274     rv = 0x440d;
 275     asm volatile ("int $0x21 ; setc %0"
 276                   :"=abcdm" (err), "+a"(rv), "=m"(dp)
 277                   :"b" (drive), "c" (0x0860), "d" (&dp));
 278
 279     if (!err)
 280         return dp.hiddensecs;
 281
 282     rv = 0x440d;
 283     asm volatile ("int $0x21 ; setc %0"
 284                   : "=abcdm" (err), "+a" (rv), "=m" (dp)
 285                   : "b" (drive), "c" (0x4860), "d" (&dp));
 286
 287     if (!err)
 288         return dp.hiddensecs;
 289
 290     die("could not find partition start offset");
 291 }
 292
 293 struct rwblock {
 294     uint8_t special;
 295     uint16_t head;
 296     uint16_t cylinder;
 297     uint16_t firstsector;
 298     uint16_t sectors;
 299     uint16_t bufferoffset;
 300     uint16_t bufferseg;
 301 } __attribute__ ((packed));
 302
 303 static struct rwblock mbr = {
 304     .special = 0,
 305     .head = 0,
 306     .cylinder = 0,
 307     .firstsector = 0,           /* MS-DOS, unlike the BIOS, zero-base sectors */
 308     .sectors = 1,
 309     .bufferoffset = 0,
 310     .bufferseg = 0
 311 };
 312
 313 void write_mbr(int drive, const void *buf)
 314 {
 315     uint16_t rv;
 316     uint8_t err;
 317
 318     dprintf("write_mbr(%d,%p)", drive, buf);
 319
 320     mbr.bufferoffset = (uintptr_t) buf;
 321     mbr.bufferseg = data_segment();
 322
 323     rv = 0x440d;
 324     asm volatile ("int $0x21 ; setc %0" : "=bcdm" (err), "+a"(rv)
 325                   :"c"(0x0841), "d"(&mbr), "b"(drive), "m"(mbr));
 326
 327     dprintf(" rv(0841) = %04x", rv);
 328     if (!err) {
 329         dprintf("\n");
 330         return;
 331     }
 332
 333     rv = 0x440d;
 334     asm volatile ("int $0x21 ; setc %0" : "=bcdm" (err), "+a"(rv)
 335                   :"c"(0x4841), "d"(&mbr), "b"(drive), "m"(mbr));
 336
 337     dprintf(" rv(4841) = %04x\n", rv);
 338     if (err)
 339         die("mbr write error");
 340 }
 341
 342 void read_mbr(int drive, const void *buf)
 343 {
 344     uint16_t rv;
 345     uint8_t err;
 346
 347     dprintf("read_mbr(%d,%p)", drive, buf);
 348
 349     mbr.bufferoffset = (uintptr_t) buf;
 350     mbr.bufferseg = data_segment();
 351
 352     rv = 0x440d;
 353     asm volatile ("int $0x21 ; setc %0":"=abcdm" (err), "+a"(rv)
 354                   :"c"(0x0861), "d"(&mbr), "b"(drive), "m"(mbr));
 355
 356     dprintf(" rv(0861) = %04x", rv);
 357     if (!err) {
 358         dprintf("\n");
 359         return;
 360     }
 361
 362     rv = 0x440d;
 363     asm volatile ("int $0x21 ; setc %0":"=abcdm" (err), "+a"(rv)
 364                   :"c"(0x4861), "d"(&mbr), "b"(drive), "m"(mbr));
 365
 366     dprintf(" rv(4841) = %04x\n", rv);
 367     if (err)
 368         die("mbr read error");
 369
 370     dprintf("Bytes: %02x %02x %02x %02x %02x %02x %02x %02x\n",
 371             ((const uint8_t *)buf)[0],
 372             ((const uint8_t *)buf)[1],
 373             ((const uint8_t *)buf)[2],
 374             ((const uint8_t *)buf)[3],
 375             ((const uint8_t *)buf)[4],
 376             ((const uint8_t *)buf)[5],
 377             ((const uint8_t *)buf)[6],
 378             ((const uint8_t *)buf)[7]);
 379 }
 380
 381 /* This call can legitimately fail, and we don't care, so ignore error return */
 382 void set_attributes(const char *file, int attributes)
 383 {
 384     uint16_t rv = 0x4301;
 385
 386     dprintf("set_attributes(\"%s\", 0x%02x)\n", file, attributes);
 387
 388     asm volatile ("int $0x21":"+a" (rv)
 389                   :"c"(attributes), "d"(file));
 390 }
 391
 392 /*
 393  * Version of the read_device function suitable for libfat
 394  */
 395 int libfat_xpread(intptr_t pp, void *buf, size_t secsize,
 396                   libfat_sector_t sector)
 397 {
 398     read_device(pp, buf, 1, sector);
 399     return secsize;
 400 }
 401
 402 static inline void get_dos_version(void)
 403 {
 404     uint16_t ver;
 405
 406     asm("int $0x21 ; xchgb %%ah,%%al"
 407         : "=a" (ver)
 408         : "a" (0x3001)
 409         : "ebx", "ecx");
 410     dos_version = ver;
 411
 412     dprintf("DOS version %d.%d\n", (dos_version >> 8), dos_version & 0xff);
 413 }
 414
 415 /* The locking interface relies on static variables.  A massive hack :( */
 416 static uint8_t lock_level, lock_drive;
 417
 418 static inline void set_lock_device(uint8_t device)
 419 {
 420     lock_level  = 0;
 421     lock_drive = device;
 422 }
 423
 424 static int do_lock(uint8_t level)
 425 {
 426     uint16_t level_arg = lock_drive + (level << 8);
 427     uint16_t rv;
 428     uint8_t err;
 429 #if 0
 430     /* DOS 7.10 = Win95 OSR2 = first version with FAT32 */
 431     uint16_t lock_call = (dos_version >= 0x070a) ? 0x484A : 0x084A;
 432 #else
 433     uint16_t lock_call = 0x084A; /* MSDN says this is OK for all filesystems */
 434 #endif
 435
 436     dprintf("Trying lock %04x... ", level_arg);
 437     asm volatile ("int $0x21 ; setc %0"
 438                   : "=bcdm" (err), "=a" (rv)
 439                   : "a" (0x440d), "b" (level_arg),
 440                     "c" (lock_call), "d" (0x0001));
 441     dprintf("%s %04x\n", err ? "err" : "ok", rv);
 442
 443     return err ? rv : 0;
 444 }
 445
 446 void lock_device(int level)
 447 {
 448     static int hard_lock = 0;
 449     int err;
 450
 451     if (dos_version < 0x0700)
 452         return;                 /* Win9x/NT only */
 453
 454     if (!hard_lock) {
 455         /* Assume hierarchial "soft" locking supported */
 456
 457         while (lock_level < level) {
 458             int new_level = lock_level + 1;
 459             err = do_lock(new_level);
 460             if (err) {
 461                 if (err == 0x0001) {
 462                     /* Try hard locking next */
 463                     hard_lock = 1;
 464                 }
 465                 goto soft_fail;
 466             }
 467
 468             lock_level = new_level;
 469         }
 470         return;
 471     }
 472
 473 soft_fail:
 474     if (hard_lock) {
 475         /* Hard locking, only level 4 supported */
 476         /* This is needed for Win9x in DOS mode */
 477
 478         err = do_lock(4);
 479         if (err) {
 480             if (err == 0x0001) {
 481                 /* Assume locking is not needed */
 482                 return;
 483             }
 484             goto hard_fail;
 485         }
 486
 487         lock_level = 4;
 488         return;
 489     }
 490
 491 hard_fail:
 492     die("could not lock device");
 493 }
 494
 495 void unlock_device(int level)
 496 {
 497     uint16_t rv;
 498     uint8_t err;
 499     uint16_t unlock_call;
 500
 501     if (dos_version < 0x0700)
 502         return;                 /* Win9x/NT only */
 503
 504 #if 0
 505     /* DOS 7.10 = Win95 OSR2 = first version with FAT32 */
 506     unlock_call = (dos_version >= 0x070a) ? 0x486A : 0x086A;
 507 #else
 508     unlock_call = 0x086A;       /* MSDN says this is OK for all filesystems */
 509 #endif
 510
 511     if (lock_level == 4 && level > 0)
 512         return;                 /* Only drop the hard lock at the end */
 513
 514     while (lock_level > level) {
 515         uint8_t new_level = (lock_level == 4) ? 0 : lock_level - 1;
 516         uint16_t level_arg = (new_level << 8) + lock_drive;
 517         rv = 0x440d;
 518         dprintf("Trying unlock %04x... ", new_level);
 519         asm volatile ("int $0x21 ; setc %0"
 520                       : "=bcdm" (err), "+a" (rv)
 521                       : "b" (level_arg), "c" (unlock_call));
 522         dprintf("%s %04x\n", err ? "err" : "ok", rv);
 523         lock_level = new_level;
 524     }
 525 }
 526
 527 /*
 528  * This function does any desired MBR manipulation; called with the device lock held.
 529  */
 530 struct mbr_entry {
 531     uint8_t active;             /* Active flag */
 532     uint8_t bhead;              /* Begin head */
 533     uint8_t bsector;            /* Begin sector */
 534     uint8_t bcylinder;          /* Begin cylinder */
 535     uint8_t filesystem;         /* Filesystem value */
 536     uint8_t ehead;              /* End head */
 537     uint8_t esector;            /* End sector */
 538     uint8_t ecylinder;          /* End cylinder */
 539     uint32_t startlba;          /* Start sector LBA */
 540     uint32_t sectors;           /* Length in sectors */
 541 } __attribute__ ((packed));
 542
 543 static void adjust_mbr(int device, int writembr, int set_active)
 544 {
 545     static unsigned char sectbuf[SECTOR_SIZE];
 546     int i;
 547
 548     if (!writembr && !set_active)
 549         return;                 /* Nothing to do */
 550
 551     read_mbr(device, sectbuf);
 552
 553     if (writembr) {
 554         memcpy(sectbuf, syslinux_mbr, syslinux_mbr_len);
 555         *(uint16_t *) (sectbuf + 510) = 0xaa55;
 556     }
 557
 558     if (set_active) {
 559         uint32_t offset = get_partition_offset(device);
 560         struct mbr_entry *me = (struct mbr_entry *)(sectbuf + 446);
 561         int found = 0;
 562
 563         dprintf("Searching for partition offset: %08x\n", offset);
 564
 565         for (i = 0; i < 4; i++) {
 566             if (me->startlba == offset) {
 567                 me->active = 0x80;
 568                 found++;
 569             } else {
 570                 me->active = 0;
 571             }
 572             me++;
 573         }
 574
 575         if (found < 1) {
 576             die("partition not found (-a is not implemented for logical partitions)");
 577         } else if (found > 1) {
 578             die("multiple aliased partitions found");
 579         }
 580     }
 581
 582     write_mbr(device, sectbuf);
 583 }
 584
 585 int main(int argc, char *argv[])
 586 {
 587     static unsigned char sectbuf[SECTOR_SIZE];
 588     int dev_fd, fd;
 589     static char ldlinux_name[] = "@:\\ldlinux.sys";
 590     struct libfat_filesystem *fs;
 591     libfat_sector_t s, *secp;
 592     libfat_sector_t *sectors;
 593     int ldlinux_sectors;
 594     int32_t ldlinux_cluster;
 595     int nsectors;
 596     const char *errmsg;
 597     int i;
 598     int patch_sectors;
 599     unsigned char *dp;
 600
 601     dprintf("argv = %p\n", argv);
 602     for (i = 0; i <= argc; i++)
 603         dprintf("argv[%d] = %p = \"%s\"\n", i, argv[i], argv[i]);
 604
 605     get_dos_version();
 606
 607     argv[0] = program;
 608     parse_options(argc, argv, MODE_SYSLINUX_DOSWIN);
 609
 610     if (!opt.device)
 611         usage(EX_USAGE, MODE_SYSLINUX_DOSWIN);
 612     if (opt.sectors || opt.heads || opt.reset_adv || opt.set_once
 613         || (opt.update_only > 0) || opt.menu_save || opt.offset) {
 614         fprintf(stderr,
 615                 "At least one specified option not yet implemented"
 616                 " for this installer.\n");
 617         exit(1);
 618     }
 619
 620     /*
 621      * Create an ADV in memory... this should be smarter.
 622      */
 623     syslinux_reset_adv(syslinux_adv);
 624
 625     /*
 626      * Figure out which drive we're talking to
 627      */
 628     dev_fd = (opt.device[0] & ~0x20) - 0x40;
 629     if (dev_fd < 1 || dev_fd > 26 || opt.device[1] != ':' || opt.device[2])
 630         usage(EX_USAGE, MODE_SYSLINUX_DOSWIN);
 631
 632     set_lock_device(dev_fd);
 633
 634     lock_device(2);             /* Make sure we can lock the device */
 635     read_device(dev_fd, sectbuf, 1, 0);
 636     unlock_device(1);
 637
 638     /*
 639      * Check to see that what we got was indeed an MS-DOS boot sector/superblock
 640      */
 641     if ((errmsg = syslinux_check_bootsect(sectbuf))) {
 642         unlock_device(0);
 643         puts(errmsg);
 644         putchar('\n');
 645         exit(1);
 646     }
 647
 648     ldlinux_name[0] = dev_fd | 0x40;
 649
 650     set_attributes(ldlinux_name, 0);
 651     fd = creat(ldlinux_name, 0);        /* SYSTEM HIDDEN READONLY */
 652     write_ldlinux(fd);
 653     write_file(fd, syslinux_adv, 2 * ADV_SIZE);
 654     close(fd);
 655     set_attributes(ldlinux_name, 0x07); /* SYSTEM HIDDEN READONLY */
 656
 657     /*
 658      * Now, use libfat to create a block map.  This probably
 659      * should be changed to use ioctl(...,FIBMAP,...) since
 660      * this is supposed to be a simple, privileged version
 661      * of the installer.
 662      */
 663     ldlinux_sectors = (syslinux_ldlinux_len + 2 * ADV_SIZE
 664                        + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
 665     sectors = calloc(ldlinux_sectors, sizeof *sectors);
 666     lock_device(2);
 667     fs = libfat_open(libfat_xpread, dev_fd);
 668     ldlinux_cluster = libfat_searchdir(fs, 0, "LDLINUX SYS", NULL);
 669     secp = sectors;
 670     nsectors = 0;
 671     s = libfat_clustertosector(fs, ldlinux_cluster);
 672     while (s && nsectors < ldlinux_sectors) {
 673         *secp++ = s;
 674         nsectors++;
 675         s = libfat_nextsector(fs, s);
 676     }
 677     libfat_close(fs);
 678
 679     /*
 680      * If requested, move ldlinux.sys
 681      */
 682     if (opt.directory) {
 683         char new_ldlinux_name[160];
 684         char *cp = new_ldlinux_name + 3;
 685         const char *sd;
 686         int slash = 1;
 687
 688         new_ldlinux_name[0] = dev_fd | 0x40;
 689         new_ldlinux_name[1] = ':';
 690         new_ldlinux_name[2] = '\\';
 691
 692         for (sd = opt.directory; *sd; sd++) {
 693             char c = *sd;
 694
 695             if (c == '/' || c == '\\') {
 696                 if (slash)
 697                     continue;
 698                 c = '\\';
 699                 slash = 1;
 700             } else {
 701                 slash = 0;
 702             }
 703
 704             *cp++ = c;
 705         }
 706
 707         /* Skip if subdirectory == root */
 708         if (cp > new_ldlinux_name + 3) {
 709             if (!slash)
 710                 *cp++ = '\\';
 711
 712             memcpy(cp, "ldlinux.sys", 12);
 713
 714             set_attributes(ldlinux_name, 0);
 715             if (rename(ldlinux_name, new_ldlinux_name))
 716                 set_attributes(ldlinux_name, 0x07);
 717             else
 718                 set_attributes(new_ldlinux_name, 0x07);
 719         }
 720     }
 721
 722     /*
 723      * Patch ldlinux.sys and the boot sector
 724      */
 725     i = syslinux_patch(sectors, nsectors, opt.stupid_mode, opt.raid_mode, opt.directory, NULL);
 726     patch_sectors = (i + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
 727
 728     /*
 729      * Overwrite the now-patched ldlinux.sys
 730      */
 731     /* lock_device(3); -- doesn't seem to be needed */
 732     dp = syslinux_ldlinux;
 733     for (i = 0; i < patch_sectors; i++) {
 734         memcpy_from_sl(sectbuf, dp, SECTOR_SIZE);
 735         dp += SECTOR_SIZE;
 736         write_device(dev_fd, sectbuf, 1, sectors[i]);
 737     }
 738
 739     /*
 740      * Muck with the MBR, if desired, while we hold the lock
 741      */
 742     adjust_mbr(dev_fd, opt.install_mbr, opt.activate_partition);
 743
 744     /*
 745      * To finish up, write the boot sector
 746      */
 747
 748     /* Read the superblock again since it might have changed while mounted */
 749     read_device(dev_fd, sectbuf, 1, 0);
 750
 751     /* Copy the syslinux code into the boot sector */
 752     syslinux_make_bootsect(sectbuf);
 753
 754     /* Write new boot sector */
 755     if (opt.bootsecfile) {
 756         unlock_device(0);
 757         fd = creat(opt.bootsecfile, 0x20);      /* ARCHIVE */
 758         write_file(fd, sectbuf, SECTOR_SIZE);
 759         close(fd);
 760     } else {
 761         write_device(dev_fd, sectbuf, 1, 0);
 762         unlock_device(0);
 763     }
 764
 765     /* Done! */
 766
 767     return 0;
 768 }