static void
g_mbr_print(int i, struct dos_partition *dp)
{
printf("[%d] f:%02x typ:%d", i, dp->dp_flag, dp->dp_typ);
printf(" s(CHS):%d/%d/%d", DPCYL(dp->dp_scyl, dp->dp_ssect),
dp->dp_shd, DPSECT(dp->dp_ssect));
printf(" e(CHS):%d/%d/%d", DPCYL(dp->dp_ecyl, dp->dp_esect),
dp->dp_ehd, DPSECT(dp->dp_esect));
printf(" s:%d l:%d\n", dp->dp_start, dp->dp_size);
}
int
mbrinit(cdev_t dev, struct disk_info *info, struct diskslices **sspp)
{
struct buf *bp;
u_char *cp;
int dospart;
struct dos_partition *dp;
struct dos_partition *dp0;
struct dos_partition dpcopy[NDOSPART];
int error;
int max_ncyls;
int max_nsectors;
int max_ntracks;
u_int64_t mbr_offset;
char partname[2];
u_long secpercyl;
char *sname = "tempname";
struct diskslice *sp;
struct diskslices *ssp;
cdev_t wdev;
mbr_offset = DOSBBSECTOR;
reread_mbr:
/*
* Don't bother if the block size is weird or the
* media size is 0 (probably means no media present).
*/
if (info->d_media_blksize & DEV_BMASK)
return (EIO);
if (info->d_media_size == 0)
return (EIO);
/*
* Read master boot record.
*/
wdev = dev;
bp = geteblk((int)info->d_media_blksize);
bp->b_bio1.bio_offset = (off_t)mbr_offset * info->d_media_blksize;
bp->b_bio1.bio_done = biodone_sync;
bp->b_bio1.bio_flags |= BIO_SYNC;
bp->b_bcount = info->d_media_blksize;
bp->b_cmd = BUF_CMD_READ;
bp->b_flags |= B_FAILONDIS;
dev_dstrategy(wdev, &bp->b_bio1);
if (biowait(&bp->b_bio1, "mbrrd") != 0) {
if ((info->d_dsflags & DSO_MBRQUIET) == 0) {
diskerr(&bp->b_bio1, wdev,
"reading primary partition table: error",
LOG_PRINTF, 0);
kprintf("\n");
}
error = EIO;
goto done;
}
/* Weakly verify it. */
cp = bp->b_data;
sname = dsname(dev, 0, 0, 0, NULL);
if (cp[0x1FE] != 0x55 || cp[0x1FF] != 0xAA) {
if (bootverbose)
kprintf("%s: invalid primary partition table: no magic\n",
sname);
error = EINVAL;
goto done;
}
/* Make a copy of the partition table to avoid alignment problems. */
memcpy(&dpcopy[0], cp + DOSPARTOFF, sizeof(dpcopy));
dp0 = &dpcopy[0];
/*
* Check for "Ontrack Diskmanager" or GPT. If a GPT is found in
* the first dos partition, ignore the rest of the MBR and go
* to GPT processing.
*/
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
if (dospart == 0 &&
(dp->dp_typ == DOSPTYP_PMBR || dp->dp_typ == DOSPTYP_GPT)) {
if (bootverbose)
kprintf(
"%s: Found GPT in slice #%d\n", sname, dospart + 1);
error = gptinit(dev, info, sspp);
goto done;
}
if (dp->dp_typ == DOSPTYP_ONTRACK) {
if (bootverbose)
kprintf(
"%s: Found \"Ontrack Disk Manager\" on this disk.\n", sname);
bp->b_flags |= B_INVAL | B_AGE;
brelse(bp);
mbr_offset = 63;
goto reread_mbr;
}
}
if (bcmp(dp0, historical_bogus_partition_table,
sizeof historical_bogus_partition_table) == 0 ||
bcmp(dp0, historical_bogus_partition_table_fixed,
sizeof historical_bogus_partition_table_fixed) == 0) {
#if 0
TRACE(("%s: invalid primary partition table: historical\n",
sname));
#endif /* 0 */
if (bootverbose)
kprintf(
"%s: invalid primary partition table: Dangerously Dedicated (ignored)\n",
sname);
error = EINVAL;
goto done;
}
/* Guess the geometry. */
/*
* TODO:
* Perhaps skip entries with 0 size.
* Perhaps only look at entries of type DOSPTYP_386BSD.
*/
max_ncyls = 0;
max_nsectors = 0;
max_ntracks = 0;
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
int ncyls;
int nsectors;
int ntracks;
ncyls = DPCYL(dp->dp_ecyl, dp->dp_esect) + 1;
if (max_ncyls < ncyls)
max_ncyls = ncyls;
nsectors = DPSECT(dp->dp_esect);
if (max_nsectors < nsectors)
max_nsectors = nsectors;
ntracks = dp->dp_ehd + 1;
if (max_ntracks < ntracks)
max_ntracks = ntracks;
}
/*
* Check that we have guessed the geometry right by checking the
* partition entries.
*/
/*
* TODO:
* As above.
* Check for overlaps.
* Check against d_secperunit if the latter is reliable.
*/
error = 0;
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++) {
if (dp->dp_scyl == 0 && dp->dp_shd == 0 && dp->dp_ssect == 0
&& dp->dp_start == 0 && dp->dp_size == 0)
continue;
//sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
// WHOLE_SLICE_PART, partname);
/*
* Temporarily ignore errors from this check. We could
* simplify things by accepting the table eariler if we
* always ignore errors here. Perhaps we should always
* accept the table if the magic is right but not let
* bad entries affect the geometry.
*/
check_part(sname, dp, mbr_offset, max_nsectors, max_ntracks,
mbr_offset);
}
if (error != 0)
goto done;
/*
* Accept the DOS partition table.
*
* Adjust the disk information structure with updated CHS
* conversion parameters, but only use values extracted from
* the primary partition table.
*
* NOTE! Regardless of our having to deal with this old cruft,
* we do not screw around with the info->d_media* parameters.
*/
secpercyl = (u_long)max_nsectors * max_ntracks;
if (secpercyl != 0 && mbr_offset == DOSBBSECTOR) {
info->d_secpertrack = max_nsectors;
info->d_nheads = max_ntracks;
info->d_secpercyl = secpercyl;
info->d_ncylinders = info->d_media_blocks / secpercyl;
}
/*
* We are passed a pointer to a suitably initialized minimal
* slices "struct" with no dangling pointers in it. Replace it
* by a maximal one. This usually oversizes the "struct", but
* enlarging it while searching for logical drives would be
* inconvenient.
*/
kfree(*sspp, M_DEVBUF);
ssp = dsmakeslicestruct(MAX_SLICES, info);
*sspp = ssp;
/* Initialize normal slices. */
sp = &ssp->dss_slices[BASE_SLICE];
for (dospart = 0, dp = dp0; dospart < NDOSPART; dospart++, dp++, sp++) {
sname = dsname(dev, dkunit(dev), BASE_SLICE + dospart,
WHOLE_SLICE_PART, partname);
(void)mbr_setslice(sname, info, sp, dp, mbr_offset);
}
ssp->dss_nslices = BASE_SLICE + NDOSPART;
/* Handle extended partitions. */
sp -= NDOSPART;
for (dospart = 0; dospart < NDOSPART; dospart++, sp++) {
if (sp->ds_type == DOSPTYP_EXTENDED ||
sp->ds_type == DOSPTYP_EXTENDEDX) {
mbr_extended(wdev, info, ssp,
sp->ds_offset, sp->ds_size, sp->ds_offset,
max_nsectors, max_ntracks, mbr_offset, 1);
}
}
/*
* mbr_extended() abuses ssp->dss_nslices for the number of slices
* that would be found if there were no limit on the number of slices
* in *ssp. Cut it back now.
*/
if (ssp->dss_nslices > MAX_SLICES)
ssp->dss_nslices = MAX_SLICES;
done:
bp->b_flags |= B_INVAL | B_AGE;
brelse(bp);
if (error == EINVAL)
error = 0;
return (error);
}
static int
check_part(char *sname, struct dos_partition *dp, u_int64_t offset,
int nsectors, int ntracks, u_int64_t mbr_offset)
{
int chs_ecyl;
int chs_esect;
int chs_scyl;
int chs_ssect;
int error;
u_long secpercyl;
u_int64_t esector;
u_int64_t esector1;
u_int64_t ssector;
u_int64_t ssector1;
secpercyl = (u_long)nsectors * ntracks;
chs_scyl = DPCYL(dp->dp_scyl, dp->dp_ssect);
chs_ssect = DPSECT(dp->dp_ssect);
ssector = chs_ssect - 1 + dp->dp_shd * nsectors + chs_scyl * secpercyl
+ mbr_offset;
ssector1 = offset + dp->dp_start;
/*
* If ssector1 is on a cylinder >= 1024, then ssector can't be right.
* Allow the C/H/S for it to be 1023/ntracks-1/nsectors, or correct
* apart from the cylinder being reduced modulo 1024. Always allow
* 1023/255/63, because this is the official way to represent
* pure-LBA for the starting position.
*/
if ((ssector < ssector1
&& ((chs_ssect == nsectors && dp->dp_shd == ntracks - 1
&& chs_scyl == 1023)
|| (secpercyl != 0
&& (ssector1 - ssector) % (1024 * secpercyl) == 0)))
|| (dp->dp_scyl == 255 && dp->dp_shd == 255
&& dp->dp_ssect == 255)) {
TRACE(("%s: C/H/S start %d/%d/%d, start %llu: allow\n",
sname, chs_scyl, dp->dp_shd, chs_ssect,
(long long)ssector1));
ssector = ssector1;
}
chs_ecyl = DPCYL(dp->dp_ecyl, dp->dp_esect);
chs_esect = DPSECT(dp->dp_esect);
esector = chs_esect - 1 + dp->dp_ehd * nsectors + chs_ecyl * secpercyl
+ mbr_offset;
esector1 = ssector1 + dp->dp_size - 1;
/*
* Allow certain bogus C/H/S values for esector, as above. However,
* heads == 255 isn't really legal and causes some BIOS crashes. The
* correct value to indicate a pure-LBA end is 1023/heads-1/sectors -
* usually 1023/254/63. "heads" is base 0, "sectors" is base 1.
*/
if ((esector < esector1
&& ((chs_esect == nsectors && dp->dp_ehd == ntracks - 1
&& chs_ecyl == 1023)
|| (secpercyl != 0
&& (esector1 - esector) % (1024 * secpercyl) == 0)))
|| (dp->dp_ecyl == 255 && dp->dp_ehd == 255
&& dp->dp_esect == 255)) {
TRACE(("%s: C/H/S end %d/%d/%d, end %llu: allow\n",
sname, chs_ecyl, dp->dp_ehd, chs_esect,
(long long)esector1));
esector = esector1;
}
error = (ssector == ssector1 && esector == esector1) ? 0 : EINVAL;
if (bootverbose)
kprintf("%s: type 0x%x, start %llu, end = %llu, size %u %s\n",
sname, dp->dp_typ,
(long long)ssector1, (long long)esector1,
dp->dp_size, (error ? "" : ": OK"));
if (ssector != ssector1 && bootverbose)
kprintf("%s: C/H/S start %d/%d/%d (%llu) != start %llu: invalid\n",
sname, chs_scyl, dp->dp_shd, chs_ssect,
(long long)ssector, (long long)ssector1);
if (esector != esector1 && bootverbose)
kprintf("%s: C/H/S end %d/%d/%d (%llu) != end %llu: invalid\n",
sname, chs_ecyl, dp->dp_ehd, chs_esect,
(long long)esector, (long long)esector1);
return (error);
}
