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-rw-r--r--exfat/mkfs/fat.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/exfat/mkfs/fat.c b/exfat/mkfs/fat.c
new file mode 100644
index 000000000..82feff8ba
--- /dev/null
+++ b/exfat/mkfs/fat.c
@@ -0,0 +1,86 @@
+/*
+ fat.c (09.11.10)
+ File Allocation Table creation code.
+
+ Copyright (C) 2011, 2012 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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <unistd.h>
+#include "fat.h"
+#include "cbm.h"
+#include "uct.h"
+#include "rootdir.h"
+
+static off64_t fat_alignment(void)
+{
+ return (off64_t) 128 * get_sector_size();
+}
+
+static off64_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,
+};