LinuxGUI/Ventoy2Disk/Lib/exfat/src/mkfs/rootdir.c

   1 /*
   2         rootdir.c (09.11.10)
   3         Root directory creation code.
   4
   5         Free exFAT implementation.
   6         Copyright (C) 2011-2018  Andrew Nayenko
   7
   8         This program is free software; you can redistribute it and/or modify
   9         it under the terms of the GNU General Public License as published by
  10         the Free Software Foundation, either version 2 of the License, or
  11         (at your option) any later version.
  12
  13         This program is distributed in the hope that it will be useful,
  14         but WITHOUT ANY WARRANTY; without even the implied warranty of
  15         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16         GNU General Public License for more details.
  17
  18         You should have received a copy of the GNU General Public License along
  19         with this program; if not, write to the Free Software Foundation, Inc.,
  20         51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21 */
  22
  23 #include "rootdir.h"
  24 #include "uct.h"
  25 #include "cbm.h"
  26 #include "uctc.h"
  27 #include <string.h>
  28
  29 static off_t rootdir_alignment(void)
  30 {
  31         return get_cluster_size();
  32 }
  33
  34 static off_t rootdir_size(void)
  35 {
  36         return get_cluster_size();
  37 }
  38
  39 static void init_label_entry(struct exfat_entry_label* label_entry)
  40 {
  41         memset(label_entry, 0, sizeof(struct exfat_entry_label));
  42         label_entry->type = EXFAT_ENTRY_LABEL ^ EXFAT_ENTRY_VALID;
  43
  44         if (utf16_length(get_volume_label()) == 0)
  45                 return;
  46
  47         memcpy(label_entry->name, get_volume_label(),
  48                         EXFAT_ENAME_MAX * sizeof(le16_t));
  49         label_entry->length = utf16_length(get_volume_label());
  50         label_entry->type |= EXFAT_ENTRY_VALID;
  51 }
  52
  53 static void init_bitmap_entry(struct exfat_entry_bitmap* bitmap_entry)
  54 {
  55         memset(bitmap_entry, 0, sizeof(struct exfat_entry_bitmap));
  56         bitmap_entry->type = EXFAT_ENTRY_BITMAP;
  57         bitmap_entry->start_cluster = cpu_to_le32(EXFAT_FIRST_DATA_CLUSTER);
  58         bitmap_entry->size = cpu_to_le64(cbm.get_size());
  59 }
  60
  61 static void init_upcase_entry(struct exfat_entry_upcase* upcase_entry)
  62 {
  63         size_t i;
  64         uint32_t sum = 0;
  65
  66         for (i = 0; i < sizeof(upcase_table); i++)
  67                 sum = ((sum << 31) | (sum >> 1)) + upcase_table[i];
  68
  69         memset(upcase_entry, 0, sizeof(struct exfat_entry_upcase));
  70         upcase_entry->type = EXFAT_ENTRY_UPCASE;
  71         upcase_entry->checksum = cpu_to_le32(sum);
  72         upcase_entry->start_cluster = cpu_to_le32(
  73                         (get_position(&uct) - get_position(&cbm)) / get_cluster_size() +
  74                         EXFAT_FIRST_DATA_CLUSTER);
  75         upcase_entry->size = cpu_to_le64(sizeof(upcase_table));
  76 }
  77
  78 static int rootdir_write(struct exfat_dev* dev)
  79 {
  80         struct exfat_entry_label label_entry;
  81         struct exfat_entry_bitmap bitmap_entry;
  82         struct exfat_entry_upcase upcase_entry;
  83
  84         init_label_entry(&label_entry);
  85         init_bitmap_entry(&bitmap_entry);
  86         init_upcase_entry(&upcase_entry);
  87
  88         if (exfat_write(dev, &label_entry, sizeof(struct exfat_entry)) < 0)
  89                 return 1;
  90         if (exfat_write(dev, &bitmap_entry, sizeof(struct exfat_entry)) < 0)
  91                 return 1;
  92         if (exfat_write(dev, &upcase_entry, sizeof(struct exfat_entry)) < 0)
  93                 return 1;
  94         return 0;
  95 }
  96
  97 const struct fs_object rootdir =
  98 {
  99         .get_alignment = rootdir_alignment,
 100         .get_size = rootdir_size,
 101         .write = rootdir_write,
 102 };