Releasing debian version 4.06+dfsg-2.
[syslinux-debian/hramrach.git] / dos / syslinux.c
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1 /* ----------------------------------------------------------------------- *
3 * Copyright 1998-2008 H. Peter Anvin - All Rights Reserved
4 * Copyright 2009-2010 Intel Corporation; author: H. Peter Anvin
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.
12 * ----------------------------------------------------------------------- */
15 * syslinux.c - Linux installer program for SYSLINUX
17 * Hacked up for DOS.
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"
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 #include "syslxfs.h"
36 char *program = "syslinux.com"; /* Name of program */
37 uint16_t dos_version;
39 #ifdef DEBUG
40 # define dprintf printf
41 void pause(void)
43 uint16_t ax;
45 asm volatile("int $0x16" : "=a" (ax) : "a" (0));
47 #else
48 # define dprintf(...) ((void)0)
49 # define pause() ((void)0)
50 #endif
52 void unlock_device(int);
54 void __attribute__ ((noreturn)) die(const char *msg)
56 unlock_device(0);
57 puts("syslinux: ");
58 puts(msg);
59 putchar('\n');
60 exit(1);
63 void warning(const char *msg)
65 puts("syslinux: warning: ");
66 puts(msg);
67 putchar('\n');
71 * read/write wrapper functions
73 int creat(const char *filename, int mode)
75 uint16_t rv;
76 uint8_t err;
78 dprintf("creat(\"%s\", 0x%x)\n", filename, mode);
80 rv = 0x3C00;
81 asm volatile ("int $0x21 ; setc %0"
82 : "=bcdm" (err), "+a" (rv)
83 : "c" (mode), "d" (filename));
84 if (err) {
85 dprintf("rv = %d\n", rv);
86 die("cannot open ldlinux.sys");
89 return rv;
92 void close(int fd)
94 uint16_t rv = 0x3E00;
96 dprintf("close(%d)\n", fd);
98 asm volatile ("int $0x21":"+a" (rv)
99 :"b"(fd));
101 /* The only error MS-DOS returns for close is EBADF,
102 and we really don't care... */
105 int rename(const char *oldname, const char *newname)
107 uint16_t rv = 0x5600; /* Also support 43FFh? */
108 uint8_t err;
110 dprintf("rename(\"%s\", \"%s\")\n", oldname, newname);
112 asm volatile ("int $0x21 ; setc %0":"=bcdm" (err), "+a"(rv)
113 :"d"(oldname), "D"(newname));
115 if (err) {
116 dprintf("rv = %d\n", rv);
117 warning("cannot move ldlinux.sys");
118 return rv;
121 return 0;
124 ssize_t write_ldlinux(int fd)
126 uint16_t ldlinux_seg = ((size_t)syslinux_ldlinux >> 4) + ds();
127 uint32_t offset = 0;
128 uint16_t rv;
129 uint8_t err;
131 while (offset < syslinux_ldlinux_len) {
132 uint32_t chunk = syslinux_ldlinux_len - offset;
133 if (chunk > 32768)
134 chunk = 32768;
135 asm volatile ("pushw %%ds ; "
136 "movw %6,%%ds ; "
137 "int $0x21 ; "
138 "popw %%ds ; " "setc %0":"=bcdm" (err), "=a"(rv)
139 :"a"(0x4000), "b"(fd), "c"(chunk), "d" (offset & 15),
140 "SD" ((uint16_t)(ldlinux_seg + (offset >> 4))));
141 if (err || rv == 0)
142 die("file write error");
143 offset += rv;
146 return offset;
149 ssize_t write_file(int fd, const void *buf, size_t count)
151 uint16_t rv;
152 ssize_t done = 0;
153 uint8_t err;
155 dprintf("write_file(%d,%p,%u)\n", fd, buf, count);
157 while (count) {
158 asm volatile ("int $0x21 ; setc %0":"=bcdm" (err), "=a"(rv)
159 :"a"(0x4000), "b"(fd), "c"(count), "d"(buf));
160 if (err || rv == 0)
161 die("file write error");
163 done += rv;
164 count -= rv;
167 return done;
170 static inline __attribute__ ((const))
171 uint16_t data_segment(void)
173 uint16_t ds;
175 asm("movw %%ds,%0" : "=rm"(ds));
176 return ds;
179 void write_device(int drive, const void *buf, size_t nsecs, unsigned int sector)
181 uint16_t errnum = 0x0001;
182 struct diskio dio;
184 dprintf("write_device(%d,%p,%u,%u)\n", drive, buf, nsecs, sector);
186 dio.startsector = sector;
187 dio.sectors = nsecs;
188 dio.bufoffs = (uintptr_t) buf;
189 dio.bufseg = data_segment();
191 if (dos_version >= 0x070a) {
192 /* Try FAT32-aware system call first */
193 asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
194 "1:"
195 : "=a" (errnum)
196 : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
197 "S" (1), "m" (dio)
198 : "memory");
199 dprintf(" rv(7305) = %04x", errnum);
202 /* If not supported, try the legacy system call (int2526.S) */
203 if (errnum == 0x0001)
204 errnum = int26_write_sector(drive, &dio);
206 if (errnum) {
207 dprintf("rv = %04x\n", errnum);
208 die("sector write error");
212 void read_device(int drive, void *buf, size_t nsecs, unsigned int sector)
214 uint16_t errnum = 0x0001;
215 struct diskio dio;
217 dprintf("read_device(%d,%p,%u,%u)\n", drive, buf, nsecs, sector);
219 dio.startsector = sector;
220 dio.sectors = nsecs;
221 dio.bufoffs = (uintptr_t) buf;
222 dio.bufseg = data_segment();
224 if (dos_version >= 0x070a) {
225 /* Try FAT32-aware system call first */
226 asm volatile("int $0x21 ; jc 1f ; xorw %0,%0\n"
227 "1:"
228 : "=a" (errnum)
229 : "a" (0x7305), "b" (&dio), "c" (-1), "d" (drive),
230 "S" (0), "m" (dio));
231 dprintf(" rv(7305) = %04x", errnum);
234 /* If not supported, try the legacy system call (int2526.S) */
235 if (errnum == 0x0001)
236 errnum = int25_read_sector(drive, &dio);
238 if (errnum) {
239 dprintf("rv = %04x\n", errnum);
240 die("sector read error");
244 /* Both traditional DOS and FAT32 DOS return this structure, but
245 FAT32 return a lot more data, so make sure we have plenty of space */
246 struct deviceparams {
247 uint8_t specfunc;
248 uint8_t devtype;
249 uint16_t devattr;
250 uint16_t cylinders;
251 uint8_t mediatype;
252 uint16_t bytespersec;
253 uint8_t secperclust;
254 uint16_t ressectors;
255 uint8_t fats;
256 uint16_t rootdirents;
257 uint16_t sectors;
258 uint8_t media;
259 uint16_t fatsecs;
260 uint16_t secpertrack;
261 uint16_t heads;
262 uint32_t hiddensecs;
263 uint32_t hugesectors;
264 uint8_t lotsofpadding[224];
265 } __attribute__ ((packed));
267 uint32_t get_partition_offset(int drive)
269 uint8_t err;
270 uint16_t rv;
271 struct deviceparams dp;
273 dp.specfunc = 1; /* Get current information */
275 rv = 0x440d;
276 asm volatile ("int $0x21 ; setc %0"
277 :"=abcdm" (err), "+a"(rv), "=m"(dp)
278 :"b" (drive), "c" (0x0860), "d" (&dp));
280 if (!err)
281 return dp.hiddensecs;
283 rv = 0x440d;
284 asm volatile ("int $0x21 ; setc %0"
285 : "=abcdm" (err), "+a" (rv), "=m" (dp)
286 : "b" (drive), "c" (0x4860), "d" (&dp));
288 if (!err)
289 return dp.hiddensecs;
291 die("could not find partition start offset");
294 struct rwblock {
295 uint8_t special;
296 uint16_t head;
297 uint16_t cylinder;
298 uint16_t firstsector;
299 uint16_t sectors;
300 uint16_t bufferoffset;
301 uint16_t bufferseg;
302 } __attribute__ ((packed));
304 static struct rwblock mbr = {
305 .special = 0,
306 .head = 0,
307 .cylinder = 0,
308 .firstsector = 0, /* MS-DOS, unlike the BIOS, zero-base sectors */
309 .sectors = 1,
310 .bufferoffset = 0,
311 .bufferseg = 0
314 void write_mbr(int drive, const void *buf)
316 uint16_t rv;
317 uint8_t err;
319 dprintf("write_mbr(%d,%p)", drive, buf);
321 mbr.bufferoffset = (uintptr_t) buf;
322 mbr.bufferseg = data_segment();
324 rv = 0x440d;
325 asm volatile ("int $0x21 ; setc %0" : "=bcdm" (err), "+a"(rv)
326 :"c"(0x0841), "d"(&mbr), "b"(drive), "m"(mbr));
328 dprintf(" rv(0841) = %04x", rv);
329 if (!err) {
330 dprintf("\n");
331 return;
334 rv = 0x440d;
335 asm volatile ("int $0x21 ; setc %0" : "=bcdm" (err), "+a"(rv)
336 :"c"(0x4841), "d"(&mbr), "b"(drive), "m"(mbr));
338 dprintf(" rv(4841) = %04x\n", rv);
339 if (err)
340 die("mbr write error");
343 void read_mbr(int drive, const void *buf)
345 uint16_t rv;
346 uint8_t err;
348 dprintf("read_mbr(%d,%p)", drive, buf);
350 mbr.bufferoffset = (uintptr_t) buf;
351 mbr.bufferseg = data_segment();
353 rv = 0x440d;
354 asm volatile ("int $0x21 ; setc %0":"=abcdm" (err), "+a"(rv)
355 :"c"(0x0861), "d"(&mbr), "b"(drive), "m"(mbr));
357 dprintf(" rv(0861) = %04x", rv);
358 if (!err) {
359 dprintf("\n");
360 return;
363 rv = 0x440d;
364 asm volatile ("int $0x21 ; setc %0":"=abcdm" (err), "+a"(rv)
365 :"c"(0x4861), "d"(&mbr), "b"(drive), "m"(mbr));
367 dprintf(" rv(4841) = %04x\n", rv);
368 if (err)
369 die("mbr read error");
371 dprintf("Bytes: %02x %02x %02x %02x %02x %02x %02x %02x\n",
372 ((const uint8_t *)buf)[0],
373 ((const uint8_t *)buf)[1],
374 ((const uint8_t *)buf)[2],
375 ((const uint8_t *)buf)[3],
376 ((const uint8_t *)buf)[4],
377 ((const uint8_t *)buf)[5],
378 ((const uint8_t *)buf)[6],
379 ((const uint8_t *)buf)[7]);
382 /* This call can legitimately fail, and we don't care, so ignore error return */
383 void set_attributes(const char *file, int attributes)
385 uint16_t rv = 0x4301;
387 dprintf("set_attributes(\"%s\", 0x%02x)\n", file, attributes);
389 asm volatile ("int $0x21":"+a" (rv)
390 :"c"(attributes), "d"(file));
394 * Version of the read_device function suitable for libfat
396 int libfat_xpread(intptr_t pp, void *buf, size_t secsize,
397 libfat_sector_t sector)
399 read_device(pp, buf, 1, sector);
400 return secsize;
403 static inline void get_dos_version(void)
405 uint16_t ver;
407 asm("int $0x21 ; xchgb %%ah,%%al"
408 : "=a" (ver)
409 : "a" (0x3001)
410 : "ebx", "ecx");
411 dos_version = ver;
413 dprintf("DOS version %d.%d\n", (dos_version >> 8), dos_version & 0xff);
416 /* The locking interface relies on static variables. A massive hack :( */
417 static uint8_t lock_level, lock_drive;
419 static inline void set_lock_device(uint8_t device)
421 lock_level = 0;
422 lock_drive = device;
425 static int do_lock(uint8_t level)
427 uint16_t level_arg = lock_drive + (level << 8);
428 uint16_t rv;
429 uint8_t err;
430 #if 0
431 /* DOS 7.10 = Win95 OSR2 = first version with FAT32 */
432 uint16_t lock_call = (dos_version >= 0x070a) ? 0x484A : 0x084A;
433 #else
434 uint16_t lock_call = 0x084A; /* MSDN says this is OK for all filesystems */
435 #endif
437 dprintf("Trying lock %04x... ", level_arg);
438 asm volatile ("int $0x21 ; setc %0"
439 : "=bcdm" (err), "=a" (rv)
440 : "a" (0x440d), "b" (level_arg),
441 "c" (lock_call), "d" (0x0001));
442 dprintf("%s %04x\n", err ? "err" : "ok", rv);
444 return err ? rv : 0;
447 void lock_device(int level)
449 static int hard_lock = 0;
450 int err;
452 if (dos_version < 0x0700)
453 return; /* Win9x/NT only */
455 if (!hard_lock) {
456 /* Assume hierarchial "soft" locking supported */
458 while (lock_level < level) {
459 int new_level = lock_level + 1;
460 err = do_lock(new_level);
461 if (err) {
462 if (err == 0x0001) {
463 /* Try hard locking next */
464 hard_lock = 1;
466 goto soft_fail;
469 lock_level = new_level;
471 return;
474 soft_fail:
475 if (hard_lock) {
476 /* Hard locking, only level 4 supported */
477 /* This is needed for Win9x in DOS mode */
479 err = do_lock(4);
480 if (err) {
481 if (err == 0x0001) {
482 /* Assume locking is not needed */
483 return;
485 goto hard_fail;
488 lock_level = 4;
489 return;
492 hard_fail:
493 die("could not lock device");
496 void unlock_device(int level)
498 uint16_t rv;
499 uint8_t err;
500 uint16_t unlock_call;
502 if (dos_version < 0x0700)
503 return; /* Win9x/NT only */
505 #if 0
506 /* DOS 7.10 = Win95 OSR2 = first version with FAT32 */
507 unlock_call = (dos_version >= 0x070a) ? 0x486A : 0x086A;
508 #else
509 unlock_call = 0x086A; /* MSDN says this is OK for all filesystems */
510 #endif
512 if (lock_level == 4 && level > 0)
513 return; /* Only drop the hard lock at the end */
515 while (lock_level > level) {
516 uint8_t new_level = (lock_level == 4) ? 0 : lock_level - 1;
517 uint16_t level_arg = (new_level << 8) + lock_drive;
518 rv = 0x440d;
519 dprintf("Trying unlock %04x... ", new_level);
520 asm volatile ("int $0x21 ; setc %0"
521 : "=bcdm" (err), "+a" (rv)
522 : "b" (level_arg), "c" (unlock_call));
523 dprintf("%s %04x\n", err ? "err" : "ok", rv);
524 lock_level = new_level;
529 * This function does any desired MBR manipulation; called with the device lock held.
531 struct mbr_entry {
532 uint8_t active; /* Active flag */
533 uint8_t bhead; /* Begin head */
534 uint8_t bsector; /* Begin sector */
535 uint8_t bcylinder; /* Begin cylinder */
536 uint8_t filesystem; /* Filesystem value */
537 uint8_t ehead; /* End head */
538 uint8_t esector; /* End sector */
539 uint8_t ecylinder; /* End cylinder */
540 uint32_t startlba; /* Start sector LBA */
541 uint32_t sectors; /* Length in sectors */
542 } __attribute__ ((packed));
544 static void adjust_mbr(int device, int writembr, int set_active)
546 static unsigned char sectbuf[SECTOR_SIZE];
547 int i;
549 if (!writembr && !set_active)
550 return; /* Nothing to do */
552 read_mbr(device, sectbuf);
554 if (writembr) {
555 memcpy(sectbuf, syslinux_mbr, syslinux_mbr_len);
556 *(uint16_t *) (sectbuf + 510) = 0xaa55;
559 if (set_active) {
560 uint32_t offset = get_partition_offset(device);
561 struct mbr_entry *me = (struct mbr_entry *)(sectbuf + 446);
562 int found = 0;
564 dprintf("Searching for partition offset: %08x\n", offset);
566 for (i = 0; i < 4; i++) {
567 if (me->startlba == offset) {
568 me->active = 0x80;
569 found++;
570 } else {
571 me->active = 0;
573 me++;
576 if (found < 1) {
577 die("partition not found (-a is not implemented for logical partitions)");
578 } else if (found > 1) {
579 die("multiple aliased partitions found");
583 write_mbr(device, sectbuf);
586 int main(int argc, char *argv[])
588 static unsigned char sectbuf[SECTOR_SIZE];
589 int dev_fd, fd;
590 static char ldlinux_name[] = "@:\\ldlinux.sys";
591 struct libfat_filesystem *fs;
592 libfat_sector_t s, *secp;
593 libfat_sector_t *sectors;
594 int ldlinux_sectors;
595 int32_t ldlinux_cluster;
596 int nsectors;
597 const char *errmsg;
598 int i;
599 int patch_sectors;
600 unsigned char *dp;
602 dprintf("argv = %p\n", argv);
603 for (i = 0; i <= argc; i++)
604 dprintf("argv[%d] = %p = \"%s\"\n", i, argv[i], argv[i]);
606 get_dos_version();
608 argv[0] = program;
609 parse_options(argc, argv, MODE_SYSLINUX_DOSWIN);
611 if (!opt.device)
612 usage(EX_USAGE, MODE_SYSLINUX_DOSWIN);
613 if (opt.sectors || opt.heads || opt.reset_adv || opt.set_once
614 || (opt.update_only > 0) || opt.menu_save || opt.offset) {
615 fprintf(stderr,
616 "At least one specified option not yet implemented"
617 " for this installer.\n");
618 exit(1);
622 * Create an ADV in memory... this should be smarter.
624 syslinux_reset_adv(syslinux_adv);
627 * Figure out which drive we're talking to
629 dev_fd = (opt.device[0] & ~0x20) - 0x40;
630 if (dev_fd < 1 || dev_fd > 26 || opt.device[1] != ':' || opt.device[2])
631 usage(EX_USAGE, MODE_SYSLINUX_DOSWIN);
633 set_lock_device(dev_fd);
635 lock_device(2); /* Make sure we can lock the device */
636 read_device(dev_fd, sectbuf, 1, 0);
637 unlock_device(1);
640 * Check to see that what we got was indeed an MS-DOS boot sector/superblock
642 if ((errmsg = syslinux_check_bootsect(sectbuf, NULL))) {
643 unlock_device(0);
644 puts(errmsg);
645 putchar('\n');
646 exit(1);
649 ldlinux_name[0] = dev_fd | 0x40;
651 set_attributes(ldlinux_name, 0);
652 fd = creat(ldlinux_name, 0); /* SYSTEM HIDDEN READONLY */
653 write_ldlinux(fd);
654 write_file(fd, syslinux_adv, 2 * ADV_SIZE);
655 close(fd);
656 set_attributes(ldlinux_name, 0x07); /* SYSTEM HIDDEN READONLY */
659 * Now, use libfat to create a block map. This probably
660 * should be changed to use ioctl(...,FIBMAP,...) since
661 * this is supposed to be a simple, privileged version
662 * of the installer.
664 ldlinux_sectors = (syslinux_ldlinux_len + 2 * ADV_SIZE
665 + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
666 sectors = calloc(ldlinux_sectors, sizeof *sectors);
667 lock_device(2);
668 fs = libfat_open(libfat_xpread, dev_fd);
669 ldlinux_cluster = libfat_searchdir(fs, 0, "LDLINUX SYS", NULL);
670 secp = sectors;
671 nsectors = 0;
672 s = libfat_clustertosector(fs, ldlinux_cluster);
673 while (s && nsectors < ldlinux_sectors) {
674 *secp++ = s;
675 nsectors++;
676 s = libfat_nextsector(fs, s);
678 libfat_close(fs);
681 * If requested, move ldlinux.sys
683 if (opt.directory) {
684 char new_ldlinux_name[160];
685 char *cp = new_ldlinux_name + 3;
686 const char *sd;
687 int slash = 1;
689 new_ldlinux_name[0] = dev_fd | 0x40;
690 new_ldlinux_name[1] = ':';
691 new_ldlinux_name[2] = '\\';
693 for (sd = opt.directory; *sd; sd++) {
694 char c = *sd;
696 if (c == '/' || c == '\\') {
697 if (slash)
698 continue;
699 c = '\\';
700 slash = 1;
701 } else {
702 slash = 0;
705 *cp++ = c;
708 /* Skip if subdirectory == root */
709 if (cp > new_ldlinux_name + 3) {
710 if (!slash)
711 *cp++ = '\\';
713 memcpy(cp, "ldlinux.sys", 12);
715 set_attributes(ldlinux_name, 0);
716 if (rename(ldlinux_name, new_ldlinux_name))
717 set_attributes(ldlinux_name, 0x07);
718 else
719 set_attributes(new_ldlinux_name, 0x07);
724 * Patch ldlinux.sys and the boot sector
726 i = syslinux_patch(sectors, nsectors, opt.stupid_mode, opt.raid_mode, opt.directory, NULL);
727 patch_sectors = (i + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
730 * Overwrite the now-patched ldlinux.sys
732 /* lock_device(3); -- doesn't seem to be needed */
733 dp = syslinux_ldlinux;
734 for (i = 0; i < patch_sectors; i++) {
735 memcpy_from_sl(sectbuf, dp, SECTOR_SIZE);
736 dp += SECTOR_SIZE;
737 write_device(dev_fd, sectbuf, 1, sectors[i]);
741 * Muck with the MBR, if desired, while we hold the lock
743 adjust_mbr(dev_fd, opt.install_mbr, opt.activate_partition);
746 * To finish up, write the boot sector
749 /* Read the superblock again since it might have changed while mounted */
750 read_device(dev_fd, sectbuf, 1, 0);
752 /* Copy the syslinux code into the boot sector */
753 syslinux_make_bootsect(sectbuf, VFAT);
755 /* Write new boot sector */
756 if (opt.bootsecfile) {
757 unlock_device(0);
758 fd = creat(opt.bootsecfile, 0x20); /* ARCHIVE */
759 write_file(fd, sectbuf, SECTOR_SIZE);
760 close(fd);
761 } else {
762 write_device(dev_fd, sectbuf, 1, 0);
763 unlock_device(0);
766 /* Done! */
768 return 0;