+++ /dev/null
-/*
- 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,
-};