Update upstream source from tag 'upstream/1.3.0+git20220115'

[sven/fuse-exfat.git] / mkfs / fat.c

diff --git a/mkfs/fat.c b/mkfs/fat.c
new file mode 100644 (file)
index 0000000..c5174a7
--- /dev/null
+++ b/mkfs/fat.c
@@ -0,0 +1,88 @@
+/*
+       fat.c (09.11.10)
+       File Allocation Table creation code.
+
+       Free exFAT implementation.
+       Copyright (C) 2011-2018  Andrew Nayenko
+
+       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 2 of the License, or
+       (at your option) any later version.
+
+       This program is distributed in the hope that it will be useful,
+       but WITHOUT ANY WARRANTY; without even the implied warranty of
+       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, write to the Free Software Foundation, Inc.,
+       51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "fat.h"
+#include "cbm.h"
+#include "uct.h"
+#include "rootdir.h"
+#include <unistd.h>
+
+static off_t fat_alignment(void)
+{
+       return (off_t) 128 * get_sector_size();
+}
+
+static off_t fat_size(void)
+{
+       return get_volume_size() / get_cluster_size() * sizeof(cluster_t);
+}
+
+static cluster_t fat_write_entry(struct exfat_dev* dev, cluster_t cluster,
+               cluster_t value)
+{
+       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, get_cluster_size());
+
+       while (cluster < end - 1)
+       {
+               cluster = fat_write_entry(dev, cluster, cluster + 1);
+               if (cluster == 0)
+                       return 0;
+       }
+       return fat_write_entry(dev, cluster, EXFAT_CLUSTER_END);
+}
+
+static int fat_write(struct exfat_dev* dev)
+{
+       cluster_t c = 0;
+
+       if (!(c = fat_write_entry(dev, c, 0xfffffff8))) /* media type */
+               return 1;
+       if (!(c = fat_write_entry(dev, c, 0xffffffff))) /* some weird constant */
+               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,
+};