X-Git-Url: https://git.sven.stormbind.net/?p=sven%2Ffuse-exfat.git;a=blobdiff_plain;f=mkfs%2Fvbr.c;fp=mkfs%2Fvbr.c;h=e40081fa9fb213cc036dbf4f726f93d9325716aa;hp=0000000000000000000000000000000000000000;hb=b747352475991e7b96183fa1014937efd3e47187;hpb=5151112c14bb7cdc93bcc66901485d94f2ab0c24

diff --git a/mkfs/vbr.c b/mkfs/vbr.c
new file mode 100644
index 0000000..e40081f
--- /dev/null
+++ b/mkfs/vbr.c
@@ -0,0 +1,148 @@
+/*
+	vbr.c (09.11.10)
+	Volume Boot Record 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 "vbr.h"
+#include "fat.h"
+#include "cbm.h"
+#include "uct.h"
+#include "rootdir.h"
+#include <string.h>
+
+static off_t vbr_alignment(void)
+{
+	return get_sector_size();
+}
+
+static off_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((off_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,
+};