/*
* Outputs an informative dump of the data in the MBR to stdout.
*/
static void
display_mbr(u_int8_t *mbr)
{
struct dos_partition *part;
int i, version;
part = (struct dos_partition *)(mbr + DOSPARTOFF);
printf(fmt0);
for (i = 0; i < NDOSPART; i++)
if (part[i].dp_typ)
printf(fmt1, 1 + i, part[i].dp_flag,
part[i].dp_scyl + ((part[i].dp_ssect & 0xc0) << 2),
part[i].dp_shd, part[i].dp_ssect & 0x3f, part[i].dp_typ,
part[i].dp_ecyl + ((part[i].dp_esect & 0xc0) << 2),
part[i].dp_ehd, part[i].dp_esect & 0x3f, part[i].dp_start,
part[i].dp_size);
printf("\n");
version = boot0version(mbr);
printf("version=%d.%d drive=0x%x mask=0x%x ticks=%u",
version >> 8, version & 0xff, mbr[OFF_DRIVE],
mbr[OFF_FLAGS] & 0xf, cv2(mbr + OFF_TICKS));
set_bell(mbr, 0, 1);
printf("\noptions=");
for (i = 0; i < nopt; i++) {
if (i)
printf(",");
if (!(mbr[OFF_FLAGS] & 1 << (7 - i)) ^ opttbl[i].def)
printf("no");
printf("%s", opttbl[i].tok);
}
printf("\n");
if (b0_ver == 2)
printf("volume serial ID %02x%02x-%02x%02x\n",
mbr[OFF_SERIAL], mbr[OFF_SERIAL+1],
mbr[OFF_SERIAL+2], mbr[OFF_SERIAL+3]);
printf("default_selection=F%d (", mbr[OFF_OPT] + 1);
if (mbr[OFF_OPT] < 4)
printf("Slice %d", mbr[OFF_OPT] + 1);
else if (mbr[OFF_OPT] == 4)
printf("Drive 1");
else
printf("PXE");
printf(")\n");
}
/*
* Read in the MBR of the disk. If it is boot0, then use the version to
* read in all of it if necessary. Use pointers to return a malloc'd
* buffer containing the MBR and then return its size.
*/
static int
read_mbr(const char *disk, u_int8_t **mbr, int check_version)
{
u_int8_t buf[MBRSIZE];
int mbr_size, fd;
int ver;
ssize_t n;
if ((fd = open(disk, O_RDONLY)) == -1)
err(1, "open %s", disk);
if ((n = read(fd, buf, MBRSIZE)) == -1)
err(1, "read %s", disk);
if (n != MBRSIZE)
errx(1, "%s: short read", disk);
if (cv2(buf + OFF_MAGIC) != 0xaa55)
errx(1, "%s: bad magic", disk);
if (! (ver = boot0bs(buf))) {
if (check_version)
errx(1, "%s: unknown or incompatible boot code", disk);
} else if (boot0version(buf) == 0x101) {
mbr_size = 1024;
if ((*mbr = malloc(mbr_size)) == NULL)
errx(1, "%s: unable to allocate read buffer", disk);
if (lseek(fd, 0, SEEK_SET) == -1 ||
(n = read(fd, *mbr, mbr_size)) == -1)
err(1, "%s", disk);
if (n != mbr_size)
errx(1, "%s: short read", disk);
close(fd);
return (mbr_size);
}
*mbr = malloc(sizeof(buf));
if (*mbr == NULL)
errx(1, "%s: unable to allocate MBR buffer", disk);
memcpy(*mbr, buf, sizeof(buf));
close(fd);
return sizeof(buf);
}
