1 ==== 1 ====
2 VFAT 2 VFAT
3 ==== 3 ====
4 4
5 USING VFAT 5 USING VFAT
6 ========== 6 ==========
7 7
8 To use the vfat filesystem, use the filesystem 8 To use the vfat filesystem, use the filesystem type 'vfat'. i.e.::
9 9
10 mount -t vfat /dev/fd0 /mnt 10 mount -t vfat /dev/fd0 /mnt
11 11
12 12
13 No special partition formatter is required, 13 No special partition formatter is required,
14 'mkdosfs' will work fine if you want to format 14 'mkdosfs' will work fine if you want to format from within Linux.
15 15
16 VFAT MOUNT OPTIONS 16 VFAT MOUNT OPTIONS
17 ================== 17 ==================
18 18
19 **uid=###** 19 **uid=###**
20 Set the owner of all files on this fil 20 Set the owner of all files on this filesystem.
21 The default is the uid of current proc 21 The default is the uid of current process.
22 22
23 **gid=###** 23 **gid=###**
24 Set the group of all files on this fil 24 Set the group of all files on this filesystem.
25 The default is the gid of current proc 25 The default is the gid of current process.
26 26
27 **umask=###** 27 **umask=###**
28 The permission mask (for files and dir 28 The permission mask (for files and directories, see *umask(1)*).
29 The default is the umask of current pr 29 The default is the umask of current process.
30 30
31 **dmask=###** 31 **dmask=###**
32 The permission mask for the directory. 32 The permission mask for the directory.
33 The default is the umask of current pr 33 The default is the umask of current process.
34 34
35 **fmask=###** 35 **fmask=###**
36 The permission mask for files. 36 The permission mask for files.
37 The default is the umask of current pr 37 The default is the umask of current process.
38 38
39 **allow_utime=###** 39 **allow_utime=###**
40 This option controls the permission ch 40 This option controls the permission check of mtime/atime.
41 41
42 **-20**: If current process is 42 **-20**: If current process is in group of file's group ID,
43 you can change timestamp. 43 you can change timestamp.
44 44
45 **-2**: Other users can change 45 **-2**: Other users can change timestamp.
46 46
47 The default is set from dmask option. 47 The default is set from dmask option. If the directory is
48 writable, utime(2) is also allowed. i. 48 writable, utime(2) is also allowed. i.e. ~dmask & 022.
49 49
50 Normally utime(2) checks current proce 50 Normally utime(2) checks current process is owner of
51 the file, or it has CAP_FOWNER capabil 51 the file, or it has CAP_FOWNER capability. But FAT
52 filesystem doesn't have uid/gid on dis 52 filesystem doesn't have uid/gid on disk, so normal
53 check is too inflexible. With this opt 53 check is too inflexible. With this option you can
54 relax it. 54 relax it.
55 55
56 **codepage=###** 56 **codepage=###**
57 Sets the codepage number for convertin 57 Sets the codepage number for converting to shortname
58 characters on FAT filesystem. 58 characters on FAT filesystem.
59 By default, FAT_DEFAULT_CODEPAGE setti 59 By default, FAT_DEFAULT_CODEPAGE setting is used.
60 60
61 **iocharset=<name>** 61 **iocharset=<name>**
62 Character set to use for converting be 62 Character set to use for converting between the
63 encoding is used for user visible file 63 encoding is used for user visible filename and 16 bit
64 Unicode characters. Long filenames are 64 Unicode characters. Long filenames are stored on disk
65 in Unicode format, but Unix for the mo 65 in Unicode format, but Unix for the most part doesn't
66 know how to deal with Unicode. 66 know how to deal with Unicode.
67 By default, FAT_DEFAULT_IOCHARSET sett 67 By default, FAT_DEFAULT_IOCHARSET setting is used.
68 68
69 There is also an option of doing UTF-8 69 There is also an option of doing UTF-8 translations
70 with the utf8 option. 70 with the utf8 option.
71 71
72 .. note:: ``iocharset=utf8`` is not recommende 72 .. note:: ``iocharset=utf8`` is not recommended. If unsure, you should consider
73 the utf8 option instead. 73 the utf8 option instead.
74 74
75 **utf8=<bool>** 75 **utf8=<bool>**
76 UTF-8 is the filesystem safe version o 76 UTF-8 is the filesystem safe version of Unicode that
77 is used by the console. It can be enab 77 is used by the console. It can be enabled or disabled
78 for the filesystem with this option. 78 for the filesystem with this option.
79 If 'uni_xlate' gets set, UTF-8 gets di 79 If 'uni_xlate' gets set, UTF-8 gets disabled.
80 By default, FAT_DEFAULT_UTF8 setting i 80 By default, FAT_DEFAULT_UTF8 setting is used.
81 81
82 **uni_xlate=<bool>** 82 **uni_xlate=<bool>**
83 Translate unhandled Unicode characters 83 Translate unhandled Unicode characters to special
84 escaped sequences. This would let you 84 escaped sequences. This would let you backup and
85 restore filenames that are created wit 85 restore filenames that are created with any Unicode
86 characters. Until Linux supports Unic 86 characters. Until Linux supports Unicode for real,
87 this gives you an alternative. Withou 87 this gives you an alternative. Without this option,
88 a '?' is used when no translation is p 88 a '?' is used when no translation is possible. The
89 escape character is ':' because it is 89 escape character is ':' because it is otherwise
90 illegal on the vfat filesystem. The e 90 illegal on the vfat filesystem. The escape sequence
91 that gets used is ':' and the four dig 91 that gets used is ':' and the four digits of hexadecimal
92 unicode. 92 unicode.
93 93
94 **nonumtail=<bool>** 94 **nonumtail=<bool>**
95 When creating 8.3 aliases, normally th 95 When creating 8.3 aliases, normally the alias will
96 end in '~1' or tilde followed by some 96 end in '~1' or tilde followed by some number. If this
97 option is set, then if the filename is 97 option is set, then if the filename is
98 "longfilename.txt" and "longfile.txt" 98 "longfilename.txt" and "longfile.txt" does not
99 currently exist in the directory, long 99 currently exist in the directory, longfile.txt will
100 be the short alias instead of longfi~1 100 be the short alias instead of longfi~1.txt.
101 101
102 **usefree** 102 **usefree**
103 Use the "free clusters" value stored o 103 Use the "free clusters" value stored on FSINFO. It will
104 be used to determine number of free cl 104 be used to determine number of free clusters without
105 scanning disk. But it's not used by de 105 scanning disk. But it's not used by default, because
106 recent Windows don't update it correct 106 recent Windows don't update it correctly in some
107 case. If you are sure the "free cluste 107 case. If you are sure the "free clusters" on FSINFO is
108 correct, by this option you can avoid 108 correct, by this option you can avoid scanning disk.
109 109
110 **quiet** 110 **quiet**
111 Stops printing certain warning message 111 Stops printing certain warning messages.
112 112
113 **check=s|r|n** 113 **check=s|r|n**
114 Case sensitivity checking setting. 114 Case sensitivity checking setting.
115 115
116 **s**: strict, case sensitive 116 **s**: strict, case sensitive
117 117
118 **r**: relaxed, case insensitive 118 **r**: relaxed, case insensitive
119 119
120 **n**: normal, default setting, curren 120 **n**: normal, default setting, currently case insensitive
121 121
122 **nocase** 122 **nocase**
123 This was deprecated for vfat. Use ``sh 123 This was deprecated for vfat. Use ``shortname=win95`` instead.
124 124
125 **shortname=lower|win95|winnt|mixed** 125 **shortname=lower|win95|winnt|mixed**
126 Shortname display/create setting. 126 Shortname display/create setting.
127 127
128 **lower**: convert to lowercase for di 128 **lower**: convert to lowercase for display,
129 emulate the Windows 95 rule for create 129 emulate the Windows 95 rule for create.
130 130
131 **win95**: emulate the Windows 95 rule 131 **win95**: emulate the Windows 95 rule for display/create.
132 132
133 **winnt**: emulate the Windows NT rule 133 **winnt**: emulate the Windows NT rule for display/create.
134 134
135 **mixed**: emulate the Windows NT rule 135 **mixed**: emulate the Windows NT rule for display,
136 emulate the Windows 95 rule for create 136 emulate the Windows 95 rule for create.
137 137
138 Default setting is `mixed`. 138 Default setting is `mixed`.
139 139
140 **tz=UTC** 140 **tz=UTC**
141 Interpret timestamps as UTC rather tha 141 Interpret timestamps as UTC rather than local time.
142 This option disables the conversion of 142 This option disables the conversion of timestamps
143 between local time (as used by Windows 143 between local time (as used by Windows on FAT) and UTC
144 (which Linux uses internally). This i 144 (which Linux uses internally). This is particularly
145 useful when mounting devices (like dig 145 useful when mounting devices (like digital cameras)
146 that are set to UTC in order to avoid 146 that are set to UTC in order to avoid the pitfalls of
147 local time. 147 local time.
148 148
149 **time_offset=minutes** 149 **time_offset=minutes**
150 Set offset for conversion of timestamp 150 Set offset for conversion of timestamps from local time
151 used by FAT to UTC. I.e. <minutes> min 151 used by FAT to UTC. I.e. <minutes> minutes will be subtracted
152 from each timestamp to convert it to U 152 from each timestamp to convert it to UTC used internally by
153 Linux. This is useful when time zone s 153 Linux. This is useful when time zone set in ``sys_tz`` is
154 not the time zone used by the filesyst 154 not the time zone used by the filesystem. Note that this
155 option still does not provide correct 155 option still does not provide correct time stamps in all
156 cases in presence of DST - time stamps 156 cases in presence of DST - time stamps in a different DST
157 setting will be off by one hour. 157 setting will be off by one hour.
158 158
159 **showexec** 159 **showexec**
160 If set, the execute permission bits of 160 If set, the execute permission bits of the file will be
161 allowed only if the extension part of 161 allowed only if the extension part of the name is .EXE,
162 .COM, or .BAT. Not set by default. 162 .COM, or .BAT. Not set by default.
163 163
164 **debug** 164 **debug**
165 Can be set, but unused by the current 165 Can be set, but unused by the current implementation.
166 166
167 **sys_immutable** 167 **sys_immutable**
168 If set, ATTR_SYS attribute on FAT is h 168 If set, ATTR_SYS attribute on FAT is handled as
169 IMMUTABLE flag on Linux. Not set by de 169 IMMUTABLE flag on Linux. Not set by default.
170 170
171 **flush** 171 **flush**
172 If set, the filesystem will try to flu 172 If set, the filesystem will try to flush to disk more
173 early than normal. Not set by default. 173 early than normal. Not set by default.
174 174
175 **rodir** 175 **rodir**
176 FAT has the ATTR_RO (read-only) attrib 176 FAT has the ATTR_RO (read-only) attribute. On Windows,
177 the ATTR_RO of the directory will just 177 the ATTR_RO of the directory will just be ignored,
178 and is used only by applications as a 178 and is used only by applications as a flag (e.g. it's set
179 for the customized folder). 179 for the customized folder).
180 180
181 If you want to use ATTR_RO as read-onl 181 If you want to use ATTR_RO as read-only flag even for
182 the directory, set this option. 182 the directory, set this option.
183 183
184 **errors=panic|continue|remount-ro** 184 **errors=panic|continue|remount-ro**
185 specify FAT behavior on critical error 185 specify FAT behavior on critical errors: panic, continue
186 without doing anything or remount the 186 without doing anything or remount the partition in
187 read-only mode (default behavior). 187 read-only mode (default behavior).
188 188
189 **discard** 189 **discard**
190 If set, issues discard/TRIM commands t 190 If set, issues discard/TRIM commands to the block
191 device when blocks are freed. This is 191 device when blocks are freed. This is useful for SSD devices
192 and sparse/thinly-provisioned LUNs. 192 and sparse/thinly-provisioned LUNs.
193 193
194 **nfs=stale_rw|nostale_ro** 194 **nfs=stale_rw|nostale_ro**
195 Enable this only if you want to export 195 Enable this only if you want to export the FAT filesystem
196 over NFS. 196 over NFS.
197 197
198 **stale_rw**: This option main 198 **stale_rw**: This option maintains an index (cache) of directory
199 *inodes* by *i_logstart* which 199 *inodes* by *i_logstart* which is used by the nfs-related code to
200 improve look-ups. Full file op 200 improve look-ups. Full file operations (read/write) over NFS is
201 supported but with cache evict 201 supported but with cache eviction at NFS server, this could
202 result in ESTALE issues. 202 result in ESTALE issues.
203 203
204 **nostale_ro**: This option ba 204 **nostale_ro**: This option bases the *inode* number and filehandle
205 on the on-disk location of a f 205 on the on-disk location of a file in the MS-DOS directory entry.
206 This ensures that ESTALE will 206 This ensures that ESTALE will not be returned after a file is
207 evicted from the inode cache. 207 evicted from the inode cache. However, it means that operations
208 such as rename, create and unl 208 such as rename, create and unlink could cause filehandles that
209 previously pointed at one file 209 previously pointed at one file to point at a different file,
210 potentially causing data corru 210 potentially causing data corruption. For this reason, this
211 option also mounts the filesys 211 option also mounts the filesystem readonly.
212 212
213 To maintain backward compatibility, `` 213 To maintain backward compatibility, ``'-o nfs'`` is also accepted,
214 defaulting to "stale_rw". 214 defaulting to "stale_rw".
215 215
216 **dos1xfloppy <bool>: 0,1,yes,no,true,false** 216 **dos1xfloppy <bool>: 0,1,yes,no,true,false**
217 If set, use a fallback default BIOS Pa 217 If set, use a fallback default BIOS Parameter Block
218 configuration, determined by backing d 218 configuration, determined by backing device size. These static
219 parameters match defaults assumed by D 219 parameters match defaults assumed by DOS 1.x for 160 kiB,
220 180 kiB, 320 kiB, and 360 kiB floppies 220 180 kiB, 320 kiB, and 360 kiB floppies and floppy images.
221 221
222 222
223 223
224 LIMITATION 224 LIMITATION
225 ========== 225 ==========
226 226
227 The fallocated region of file is discarded at 227 The fallocated region of file is discarded at umount/evict time
228 when using fallocate with FALLOC_FL_KEEP_SIZE. 228 when using fallocate with FALLOC_FL_KEEP_SIZE.
229 So, User should assume that fallocated region 229 So, User should assume that fallocated region can be discarded at
230 last close if there is memory pressure resulti 230 last close if there is memory pressure resulting in eviction of
231 the inode from the memory. As a result, for an 231 the inode from the memory. As a result, for any dependency on
232 the fallocated region, user should make sure t 232 the fallocated region, user should make sure to recheck fallocate
233 after reopening the file. 233 after reopening the file.
234 234
235 TODO 235 TODO
236 ==== 236 ====
237 Need to get rid of the raw scanning stuff. In 237 Need to get rid of the raw scanning stuff. Instead, always use
238 a get next directory entry approach. The only 238 a get next directory entry approach. The only thing left that uses
239 raw scanning is the directory renaming code. 239 raw scanning is the directory renaming code.
240 240
241 241
242 POSSIBLE PROBLEMS 242 POSSIBLE PROBLEMS
243 ================= 243 =================
244 244
245 - vfat_valid_longname does not properly checke 245 - vfat_valid_longname does not properly checked reserved names.
246 - When a volume name is the same as a director 246 - When a volume name is the same as a directory name in the root
247 directory of the filesystem, the directory n 247 directory of the filesystem, the directory name sometimes shows
248 up as an empty file. 248 up as an empty file.
249 - autoconv option does not work correctly. 249 - autoconv option does not work correctly.
250 250
251 251
252 TEST SUITE 252 TEST SUITE
253 ========== 253 ==========
254 If you plan to make any modifications to the v 254 If you plan to make any modifications to the vfat filesystem, please
255 get the test suite that comes with the vfat di 255 get the test suite that comes with the vfat distribution at
256 256
257 `<http://web.archive.org/web/*/http://bmrc.ber 257 `<http://web.archive.org/web/*/http://bmrc.berkeley.edu/people/chaffee/vfat.html>`_
258 258
259 This tests quite a few parts of the vfat files 259 This tests quite a few parts of the vfat filesystem and additional
260 tests for new features or untested features wo 260 tests for new features or untested features would be appreciated.
261 261
262 NOTES ON THE STRUCTURE OF THE VFAT FILESYSTEM 262 NOTES ON THE STRUCTURE OF THE VFAT FILESYSTEM
263 ============================================= 263 =============================================
264 This documentation was provided by Galen C. Hu 264 This documentation was provided by Galen C. Hunt gchunt@cs.rochester.edu and
265 lightly annotated by Gordon Chaffee. 265 lightly annotated by Gordon Chaffee.
266 266
267 This document presents a very rough, technical 267 This document presents a very rough, technical overview of my
268 knowledge of the extended FAT file system used 268 knowledge of the extended FAT file system used in Windows NT 3.5 and
269 Windows 95. I don't guarantee that any of the 269 Windows 95. I don't guarantee that any of the following is correct,
270 but it appears to be so. 270 but it appears to be so.
271 271
272 The extended FAT file system is almost identic 272 The extended FAT file system is almost identical to the FAT
273 file system used in DOS versions up to and inc 273 file system used in DOS versions up to and including *6.223410239847*
274 :-). The significant change has been the addi 274 :-). The significant change has been the addition of long file names.
275 These names support up to 255 characters inclu 275 These names support up to 255 characters including spaces and lower
276 case characters as opposed to the traditional 276 case characters as opposed to the traditional 8.3 short names.
277 277
278 Here is the description of the traditional FAT 278 Here is the description of the traditional FAT entry in the current
279 Windows 95 filesystem:: 279 Windows 95 filesystem::
280 280
281 struct directory { // Short 8.3 names 281 struct directory { // Short 8.3 names
282 unsigned char name[8]; 282 unsigned char name[8]; // file name
283 unsigned char ext[3]; 283 unsigned char ext[3]; // file extension
284 unsigned char attr; 284 unsigned char attr; // attribute byte
285 unsigned char lcase; 285 unsigned char lcase; // Case for base and extension
286 unsigned char ctime_ms; 286 unsigned char ctime_ms; // Creation time, milliseconds
287 unsigned char ctime[2]; 287 unsigned char ctime[2]; // Creation time
288 unsigned char cdate[2]; 288 unsigned char cdate[2]; // Creation date
289 unsigned char adate[2]; 289 unsigned char adate[2]; // Last access date
290 unsigned char reserved[2]; 290 unsigned char reserved[2]; // reserved values (ignored)
291 unsigned char time[2]; 291 unsigned char time[2]; // time stamp
292 unsigned char date[2]; 292 unsigned char date[2]; // date stamp
293 unsigned char start[2]; 293 unsigned char start[2]; // starting cluster number
294 unsigned char size[4]; 294 unsigned char size[4]; // size of the file
295 }; 295 };
296 296
297 297
298 The lcase field specifies if the base and/or t 298 The lcase field specifies if the base and/or the extension of an 8.3
299 name should be capitalized. This field does n 299 name should be capitalized. This field does not seem to be used by
300 Windows 95 but it is used by Windows NT. The 300 Windows 95 but it is used by Windows NT. The case of filenames is not
301 completely compatible from Windows NT to Windo 301 completely compatible from Windows NT to Windows 95. It is not completely
302 compatible in the reverse direction, however. 302 compatible in the reverse direction, however. Filenames that fit in
303 the 8.3 namespace and are written on Windows N 303 the 8.3 namespace and are written on Windows NT to be lowercase will
304 show up as uppercase on Windows 95. 304 show up as uppercase on Windows 95.
305 305
306 .. note:: Note that the ``start`` and ``size`` 306 .. note:: Note that the ``start`` and ``size`` values are actually little
307 endian integer values. The descript 307 endian integer values. The descriptions of the fields in this
308 structure are public knowledge and c 308 structure are public knowledge and can be found elsewhere.
309 309
310 With the extended FAT system, Microsoft has in 310 With the extended FAT system, Microsoft has inserted extra
311 directory entries for any files with extended 311 directory entries for any files with extended names. (Any name which
312 legally fits within the old 8.3 encoding schem 312 legally fits within the old 8.3 encoding scheme does not have extra
313 entries.) I call these extra entries slots. 313 entries.) I call these extra entries slots. Basically, a slot is a
314 specially formatted directory entry which hold 314 specially formatted directory entry which holds up to 13 characters of
315 a file's extended name. Think of slots as add 315 a file's extended name. Think of slots as additional labeling for the
316 directory entry of the file to which they corr 316 directory entry of the file to which they correspond. Microsoft
317 prefers to refer to the 8.3 entry for a file a 317 prefers to refer to the 8.3 entry for a file as its alias and the
318 extended slot directory entries as the file na 318 extended slot directory entries as the file name.
319 319
320 The C structure for a slot directory entry fol 320 The C structure for a slot directory entry follows::
321 321
322 struct slot { // Up to 13 characters o 322 struct slot { // Up to 13 characters of a long name
323 unsigned char id; 323 unsigned char id; // sequence number for slot
324 unsigned char name0_4[10]; 324 unsigned char name0_4[10]; // first 5 characters in name
325 unsigned char attr; 325 unsigned char attr; // attribute byte
326 unsigned char reserved; 326 unsigned char reserved; // always 0
327 unsigned char alias_checksum; 327 unsigned char alias_checksum; // checksum for 8.3 alias
328 unsigned char name5_10[12]; 328 unsigned char name5_10[12]; // 6 more characters in name
329 unsigned char start[2]; 329 unsigned char start[2]; // starting cluster number
330 unsigned char name11_12[4]; 330 unsigned char name11_12[4]; // last 2 characters in name
331 }; 331 };
332 332
333 333
334 If the layout of the slots looks a little odd, 334 If the layout of the slots looks a little odd, it's only
335 because of Microsoft's efforts to maintain com 335 because of Microsoft's efforts to maintain compatibility with old
336 software. The slots must be disguised to prev 336 software. The slots must be disguised to prevent old software from
337 panicking. To this end, a number of measures 337 panicking. To this end, a number of measures are taken:
338 338
339 1) The attribute byte for a slot direc 339 1) The attribute byte for a slot directory entry is always set
340 to 0x0f. This corresponds to an ol 340 to 0x0f. This corresponds to an old directory entry with
341 attributes of "hidden", "system", " 341 attributes of "hidden", "system", "read-only", and "volume
342 label". Most old software will ign 342 label". Most old software will ignore any directory
343 entries with the "volume label" bit 343 entries with the "volume label" bit set. Real volume label
344 entries don't have the other three 344 entries don't have the other three bits set.
345 345
346 2) The starting cluster is always set 346 2) The starting cluster is always set to 0, an impossible
347 value for a DOS file. 347 value for a DOS file.
348 348
349 Because the extended FAT system is backward co 349 Because the extended FAT system is backward compatible, it is
350 possible for old software to modify directory 350 possible for old software to modify directory entries. Measures must
351 be taken to ensure the validity of slots. An 351 be taken to ensure the validity of slots. An extended FAT system can
352 verify that a slot does in fact belong to an 8 352 verify that a slot does in fact belong to an 8.3 directory entry by
353 the following: 353 the following:
354 354
355 1) Positioning. Slots for a file alwa 355 1) Positioning. Slots for a file always immediately proceed
356 their corresponding 8.3 directory e 356 their corresponding 8.3 directory entry. In addition, each
357 slot has an id which marks its orde 357 slot has an id which marks its order in the extended file
358 name. Here is a very abbreviated v 358 name. Here is a very abbreviated view of an 8.3 directory
359 entry and its corresponding long na 359 entry and its corresponding long name slots for the file
360 "My Big File.Extension which is lon 360 "My Big File.Extension which is long"::
361 361
362 <proceeding files...> 362 <proceeding files...>
363 <slot #3, id = 0x43, character 363 <slot #3, id = 0x43, characters = "h is long">
364 <slot #2, id = 0x02, character 364 <slot #2, id = 0x02, characters = "xtension whic">
365 <slot #1, id = 0x01, character 365 <slot #1, id = 0x01, characters = "My Big File.E">
366 <directory entry, name = "MYBI 366 <directory entry, name = "MYBIGFIL.EXT">
367 367
368 368
369 .. note:: Note that the slots are s 369 .. note:: Note that the slots are stored from last to first. Slots
370 are numbered from 1 to N. 370 are numbered from 1 to N. The Nth slot is ``or'ed`` with
371 0x40 to mark it as the la 371 0x40 to mark it as the last one.
372 372
373 2) Checksum. Each slot has an alias_c 373 2) Checksum. Each slot has an alias_checksum value. The
374 checksum is calculated from the 8.3 374 checksum is calculated from the 8.3 name using the
375 following algorithm:: 375 following algorithm::
376 376
377 for (sum = i = 0; i < 11; i++) 377 for (sum = i = 0; i < 11; i++) {
378 sum = (((sum&1)<<7)|(( 378 sum = (((sum&1)<<7)|((sum&0xfe)>>1)) + name[i]
379 } 379 }
380 380
381 381
382 3) If there is free space in the final 382 3) If there is free space in the final slot, a Unicode ``NULL (0x0000)``
383 is stored after the final character 383 is stored after the final character. After that, all unused
384 characters in the final slot are se 384 characters in the final slot are set to Unicode 0xFFFF.
385 385
386 Finally, note that the extended name is stored 386 Finally, note that the extended name is stored in Unicode. Each Unicode
387 character takes either two or four bytes, UTF- 387 character takes either two or four bytes, UTF-16LE encoded.
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