@@ -125,7 +125,6 @@ static const FDFormat fd_formats[] = {
{ FLOPPY_DRIVE_TYPE_NONE, -1, -1, 0, 0, },
};
-__attribute__((__unused__))
static FDriveSize drive_size(FloppyDriveType drive)
{
switch (drive) {
@@ -284,45 +283,78 @@ static int pick_geometry(FDrive *drv)
BlockBackend *blk = drv->blk;
const FDFormat *parse;
uint64_t nb_sectors, size;
- int i, first_match, match;
+ int i;
+ int match, size_match, type_match;
+ bool magic = drv->drive == FLOPPY_DRIVE_TYPE_AUTO;
/* We can only pick a geometry if we have a diskette. */
if (!drv->media_inserted || drv->drive == FLOPPY_DRIVE_TYPE_NONE) {
return -1;
}
+ /* We need to determine the likely geometry of the inserted medium.
+ * In order of preference, we look for:
+ * (1) The same drive type and number of sectors,
+ * (2) The same diskette size and number of sectors,
+ * (3) The same drive type.
+ *
+ * In all cases, matches that occur higher in the drive table will take
+ * precedence over matches that occur later in the table.
+ */
blk_get_geometry(blk, &nb_sectors);
- match = -1;
- first_match = -1;
+ match = size_match = type_match = -1;
for (i = 0; ; i++) {
parse = &fd_formats[i];
if (parse->drive == FLOPPY_DRIVE_TYPE_NONE) {
break;
}
- if (drv->drive == parse->drive ||
- drv->drive == FLOPPY_DRIVE_TYPE_AUTO) {
- size = (parse->max_head + 1) * parse->max_track *
- parse->last_sect;
- if (nb_sectors == size) {
- match = i;
- break;
+ size = (parse->max_head + 1) * parse->max_track * parse->last_sect;
+ if (nb_sectors == size) {
+ if (magic || parse->drive == drv->drive) {
+ /* (1) perfect match -- nb_sectors and drive type */
+ goto out;
+ } else if (drive_size(parse->drive) == drive_size(drv->drive)) {
+ /* (2) size match -- nb_sectors and physical medium size */
+ match = (match == -1) ? i : match;
+ } else {
+ /* This is suspicious -- Did the user misconfigure? */
+ size_match = (size_match == -1) ? i : size_match;
}
- if (first_match == -1) {
- first_match = i;
+ } else if (type_match == -1) {
+ if ((parse->drive == drv->drive) ||
+ (magic && (parse->drive == get_fallback_drive_type(drv)))) {
+ /* (3) type match -- nb_sectors mismatch, but matches the type
+ * specified explicitly by the user, or matches the fallback
+ * default type when using the drive autodetect mechanism */
+ type_match = i;
}
}
}
+
+ /* No exact match found */
if (match == -1) {
- if (first_match == -1) {
- error_setg(&error_abort, "No candidate geometries present in table "
- " for floppy drive type '%s'",
- FloppyDriveType_lookup[drv->drive]);
- } else {
- match = first_match;
+ if (size_match != -1) {
+ parse = &fd_formats[size_match];
+ FLOPPY_DPRINTF("User requested floppy drive type '%s', "
+ "but inserted medium appears to be a "
+ "%d sector '%s' type\n",
+ FloppyDriveType_lookup[drv->drive],
+ nb_sectors,
+ FloppyDriveType_lookup[parse->drive]);
}
- parse = &fd_formats[match];
+ match = type_match;
}
+ /* No match of any kind found -- fd_format is misconfigured, abort. */
+ if (match == -1) {
+ error_setg(&error_abort, "No candidate geometries present in table "
+ " for floppy drive type '%s'",
+ FloppyDriveType_lookup[drv->drive]);
+ }
+
+ parse = &(fd_formats[match]);
+
+ out:
if (parse->max_head == 0) {
drv->flags &= ~FDISK_DBL_SIDES;
} else {