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| author | Markus Armbruster <armbru@redhat.com> | 2012-07-10 11:12:28 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2012-07-17 16:48:30 +0200 |
| commit | f91cbefe2d0eb3f7b5071bcb1fd3a02970f1a776 (patch) | |
| tree | 594406d70071e882dc5b273148a727bd5d206a07 /block/vvfat.c | |
| parent | 61a8d649ff1e125966b51d688ff43dc6ef6ca63b (diff) | |
| download | qemu-f91cbefe2d0eb3f7b5071bcb1fd3a02970f1a776.tar.gz | |
vvfat: Fix partition table
Unless parameter ":floppy:" is given, vvfat creates a virtual image
with DOS MBR defining a single partition which holds the FAT file
system. The size of the virtual image depends on the width of the
FAT: 32 MiB (CHS 64, 16, 63) for 12 bit FAT, 504 MiB (CHS 1024, 16,
63) for 16 and 32 bit FAT, leaving (64*16-1)*63 = 64449 and
(1024*16-1)*64 = 1032129 sectors for the partition.
However, it screws up the end of the partition in the MBR:
FAT width param. start CHS end CHS start LBA size
:32: 0,1,1 1023,14,63 63 1032065
:16: 0,1,1 1023,14,55 63 1032057
:12: 0,1,1 63,14,55 63 64377
The actual FAT file system nevertheless assumes the partition has
1032129 or 64449 sectors. Oops.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Diffstat (limited to 'block/vvfat.c')
| -rw-r--r-- | block/vvfat.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/block/vvfat.c b/block/vvfat.c index 0fd3367d82..e2b83a21a0 100644 --- a/block/vvfat.c +++ b/block/vvfat.c @@ -394,11 +394,12 @@ static void init_mbr(BDRVVVFATState* s) /* LBA is used when partition is outside the CHS geometry */ lba = sector2CHS(s->bs, &partition->start_CHS, s->first_sectors_number-1); - lba|= sector2CHS(s->bs, &partition->end_CHS, s->sector_count); + lba |= sector2CHS(s->bs, &partition->end_CHS, s->bs->total_sectors - 1); /*LBA partitions are identified only by start/length_sector_long not by CHS*/ - partition->start_sector_long =cpu_to_le32(s->first_sectors_number-1); - partition->length_sector_long=cpu_to_le32(s->sector_count - s->first_sectors_number+1); + partition->start_sector_long = cpu_to_le32(s->first_sectors_number - 1); + partition->length_sector_long = cpu_to_le32(s->bs->total_sectors + - s->first_sectors_number + 1); /* FAT12/FAT16/FAT32 */ /* DOS uses different types when partition is LBA, |