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-rw-r--r--exfat/mkfs/vbr.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/exfat/mkfs/vbr.c b/exfat/mkfs/vbr.c
new file mode 100644
index 000000000..bbf1304d9
--- /dev/null
+++ b/exfat/mkfs/vbr.c
@@ -0,0 +1,148 @@
+/*
+ vbr.c (09.11.10)
+ Volume Boot Record creation code.
+
+ Free exFAT implementation.
+ Copyright (C) 2011-2013 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 <string.h>
+#include "vbr.h"
+#include "fat.h"
+#include "cbm.h"
+#include "uct.h"
+#include "rootdir.h"
+
+static off64_t vbr_alignment(void)
+{
+ return get_sector_size();
+}
+
+static off64_t vbr_size(void)
+{
+ return 12 * get_sector_size();
+}
+
+static void init_sb(struct exfat_super_block* sb)
+{
+ uint32_t clusters_max;
+ uint32_t fat_sectors;
+
+ clusters_max = get_volume_size() / get_cluster_size();
+ fat_sectors = DIV_ROUND_UP((off64_t) clusters_max * sizeof(cluster_t),
+ get_sector_size());
+
+ memset(sb, 0, sizeof(struct exfat_super_block));
+ sb->jump[0] = 0xeb;
+ sb->jump[1] = 0x76;
+ sb->jump[2] = 0x90;
+ memcpy(sb->oem_name, "EXFAT ", sizeof(sb->oem_name));
+ sb->sector_start = cpu_to_le64(get_first_sector());
+ sb->sector_count = cpu_to_le64(get_volume_size() / get_sector_size());
+ sb->fat_sector_start = cpu_to_le32(
+ fat.get_alignment() / get_sector_size());
+ sb->fat_sector_count = cpu_to_le32(ROUND_UP(
+ le32_to_cpu(sb->fat_sector_start) + fat_sectors,
+ 1 << get_spc_bits()) -
+ le32_to_cpu(sb->fat_sector_start));
+ sb->cluster_sector_start = cpu_to_le32(
+ get_position(&cbm) / get_sector_size());
+ sb->cluster_count = cpu_to_le32(clusters_max -
+ ((le32_to_cpu(sb->fat_sector_start) +
+ le32_to_cpu(sb->fat_sector_count)) >> get_spc_bits()));
+ sb->rootdir_cluster = cpu_to_le32(
+ (get_position(&rootdir) - get_position(&cbm)) / get_cluster_size()
+ + EXFAT_FIRST_DATA_CLUSTER);
+ sb->volume_serial = cpu_to_le32(get_volume_serial());
+ sb->version.major = 1;
+ sb->version.minor = 0;
+ sb->volume_state = cpu_to_le16(0);
+ sb->sector_bits = get_sector_bits();
+ sb->spc_bits = get_spc_bits();
+ sb->fat_count = 1;
+ sb->drive_no = 0x80;
+ sb->allocated_percent = 0;
+ sb->boot_signature = cpu_to_le16(0xaa55);
+}
+
+static int vbr_write(struct exfat_dev* dev)
+{
+ struct exfat_super_block sb;
+ uint32_t checksum;
+ le32_t* sector = malloc(get_sector_size());
+ size_t i;
+
+ if (sector == NULL)
+ {
+ exfat_error("failed to allocate sector-sized block of memory");
+ return 1;
+ }
+
+ init_sb(&sb);
+ if (exfat_write(dev, &sb, sizeof(struct exfat_super_block)) < 0)
+ {
+ free(sector);
+ exfat_error("failed to write super block sector");
+ return 1;
+ }
+ checksum = exfat_vbr_start_checksum(&sb, sizeof(struct exfat_super_block));
+
+ memset(sector, 0, get_sector_size());
+ sector[get_sector_size() / sizeof(sector[0]) - 1] =
+ cpu_to_le32(0xaa550000);
+ for (i = 0; i < 8; i++)
+ {
+ if (exfat_write(dev, sector, get_sector_size()) < 0)
+ {
+ free(sector);
+ exfat_error("failed to write a sector with boot signature");
+ return 1;
+ }
+ checksum = exfat_vbr_add_checksum(sector, get_sector_size(), checksum);
+ }
+
+ memset(sector, 0, get_sector_size());
+ for (i = 0; i < 2; i++)
+ {
+ if (exfat_write(dev, sector, get_sector_size()) < 0)
+ {
+ free(sector);
+ exfat_error("failed to write an empty sector");
+ return 1;
+ }
+ checksum = exfat_vbr_add_checksum(sector, get_sector_size(), checksum);
+ }
+
+ for (i = 0; i < get_sector_size() / sizeof(sector[0]); i++)
+ sector[i] = cpu_to_le32(checksum);
+ if (exfat_write(dev, sector, get_sector_size()) < 0)
+ {
+ free(sector);
+ exfat_error("failed to write checksum sector");
+ return 1;
+ }
+
+ free(sector);
+ return 0;
+}
+
+const struct fs_object vbr =
+{
+ .get_alignment = vbr_alignment,
+ .get_size = vbr_size,
+ .write = vbr_write,
+};