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
rootdir_alignment(void)29 static off_t rootdir_alignment(void)
30 {
31 return get_cluster_size();
32 }
33
rootdir_size(void)34 static off_t rootdir_size(void)
35 {
36 return get_cluster_size();
37 }
38
init_label_entry(struct exfat_entry_label * label_entry)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
init_bitmap_entry(struct exfat_entry_bitmap * bitmap_entry)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
init_upcase_entry(struct exfat_entry_upcase * upcase_entry)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
rootdir_write(struct exfat_dev * dev)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 };
103