vvfat: reorganize computation of disk geometry
First determine FAT12/16/32, then compute geometry from that for both
FDD and HDD. For 1.44MB floppies, and 2.88MB floppies using FAT16,
change to 1 sector/cluster. The default remains 2.88MB with FAT12
and 2 sectors/cluster. Both DOS and mkdosfs by default format a 2.88MB
floppy as FAT12.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/vvfat.c b/block/vvfat.c
index faf2947..8511fe5 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -982,7 +982,6 @@
static int vvfat_open(BlockDriverState *bs, const char* dirname, int flags)
{
BDRVVVFATState *s = bs->opaque;
- int floppy = 0;
int i;
#ifdef DEBUG
@@ -996,11 +995,8 @@
s->bs = bs;
- s->fat_type=16;
/* LATER TODO: if FAT32, adjust */
s->sectors_per_cluster=0x10;
- /* 504MB disk*/
- bs->cyls=1024; bs->heads=16; bs->secs=63;
s->current_cluster=0xffffffff;
@@ -1015,14 +1011,6 @@
if (!strstart(dirname, "fat:", NULL))
return -1;
- if (strstr(dirname, ":floppy:")) {
- floppy = 1;
- s->fat_type = 12;
- s->first_sectors_number = 1;
- s->sectors_per_cluster=2;
- bs->cyls = 80; bs->heads = 2; bs->secs = 36;
- }
-
if (strstr(dirname, ":32:")) {
fprintf(stderr, "Big fat greek warning: FAT32 has not been tested. You are welcome to do so!\n");
s->fat_type = 32;
@@ -1030,7 +1018,27 @@
s->fat_type = 16;
} else if (strstr(dirname, ":12:")) {
s->fat_type = 12;
- bs->secs = 18;
+ }
+
+ if (strstr(dirname, ":floppy:")) {
+ /* 1.44MB or 2.88MB floppy. 2.88MB can be FAT12 (default) or FAT16. */
+ if (!s->fat_type) {
+ s->fat_type = 12;
+ bs->secs = 36;
+ s->sectors_per_cluster=2;
+ } else {
+ bs->secs=(s->fat_type == 12 ? 18 : 36);
+ s->sectors_per_cluster=1;
+ }
+ s->first_sectors_number = 1;
+ bs->cyls=80; bs->heads=2;
+ } else {
+ /* 32MB or 504MB disk*/
+ if (!s->fat_type) {
+ s->fat_type = 16;
+ }
+ bs->cyls=(s->fat_type == 12 ? 64 : 1024);
+ bs->heads=16; bs->secs=63;
}
s->sector_count=bs->cyls*bs->heads*bs->secs-(s->first_sectors_number-1);
@@ -1058,10 +1066,10 @@
if(s->first_sectors_number==0x40)
init_mbr(s);
-
- /* for some reason or other, MS-DOS does not like to know about CHS... */
- if (floppy)
+ else {
+ /* MS-DOS does not like to know about CHS (?). */
bs->heads = bs->cyls = bs->secs = 0;
+ }
// assert(is_consistent(s));
qemu_co_mutex_init(&s->lock);
