fat.c (09.11.10)
File Allocation Table creation code.
- Copyright (C) 2009, 2010 Andrew Nayenko
+ Free exFAT implementation.
+ Copyright (C) 2011-2018 Andrew Nayenko
- This program is free software: you can redistribute it and/or modify
+ This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
+ the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#include <unistd.h>
-#include <inttypes.h>
-#include <errno.h>
-#include "mkexfat.h"
+#include "fat.h"
#include "cbm.h"
#include "uct.h"
#include "rootdir.h"
+#include <unistd.h>
-off_t fat_alignment(void)
+static off_t fat_alignment(void)
{
- return (off_t) le32_to_cpu(sb.fat_sector_start) * SECTOR_SIZE(sb);
+ return (off_t) 128 * get_sector_size();
}
-off_t fat_size(void)
+static off_t fat_size(void)
{
- return (off_t) le32_to_cpu(sb.fat_sector_count) * SECTOR_SIZE(sb);
+ return get_volume_size() / get_cluster_size() * sizeof(cluster_t);
}
static cluster_t fat_write_entry(struct exfat_dev* dev, cluster_t cluster,
{
le32_t fat_entry = cpu_to_le32(value);
if (exfat_write(dev, &fat_entry, sizeof(fat_entry)) < 0)
+ {
+ exfat_error("failed to write FAT entry 0x%x", value);
return 0;
+ }
return cluster + 1;
}
static cluster_t fat_write_entries(struct exfat_dev* dev, cluster_t cluster,
uint64_t length)
{
- cluster_t end = cluster + DIV_ROUND_UP(length, CLUSTER_SIZE(sb));
+ cluster_t end = cluster + DIV_ROUND_UP(length, get_cluster_size());
while (cluster < end - 1)
{
return fat_write_entry(dev, cluster, EXFAT_CLUSTER_END);
}
-int fat_write(struct exfat_dev* dev, off_t base)
+static int fat_write(struct exfat_dev* dev)
{
cluster_t c = 0;
- if (base != le32_to_cpu(sb.fat_sector_start) * SECTOR_SIZE(sb))
- exfat_bug("unexpected FAT location: %"PRIu64" (expected %u)",
- base, le32_to_cpu(sb.fat_sector_start) * SECTOR_SIZE(sb));
-
if (!(c = fat_write_entry(dev, c, 0xfffffff8))) /* media type */
- return errno;
+ return 1;
if (!(c = fat_write_entry(dev, c, 0xffffffff))) /* some weird constant */
- return errno;
- if (!(c = fat_write_entries(dev, c, cbm_size())))
- return errno;
- if (!(c = fat_write_entries(dev, c, uct_size())))
- return errno;
- if (!(c = fat_write_entries(dev, c, rootdir_size())))
- return errno;
+ return 1;
+ if (!(c = fat_write_entries(dev, c, cbm.get_size())))
+ return 1;
+ if (!(c = fat_write_entries(dev, c, uct.get_size())))
+ return 1;
+ if (!(c = fat_write_entries(dev, c, rootdir.get_size())))
+ return 1;
return 0;
}
+
+const struct fs_object fat =
+{
+ .get_alignment = fat_alignment,
+ .get_size = fat_size,
+ .write = fat_write,
+};