source: mainline/tools/mkfat.py@ 28f4adb

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 28f4adb was 28f4adb, checked in by Martin Decky <martin@…>, 15 years ago

update scripts for compatibility with Python 3 (thx Vojtech Horky and Martin Sucha)
  • Property mode set to 100755
File size: 13.2 KB
Line 
1#!/usr/bin/env python
2#
3# Copyright (c) 2008 Martin Decky
4# All rights reserved.
5#
6# Redistribution and use in source and binary forms, with or without
7# modification, are permitted provided that the following conditions
8# are met:
9#
10# - Redistributions of source code must retain the above copyright
11# notice, this list of conditions and the following disclaimer.
12# - Redistributions in binary form must reproduce the above copyright
13# notice, this list of conditions and the following disclaimer in the
14# documentation and/or other materials provided with the distribution.
15# - The name of the author may not be used to endorse or promote products
16# derived from this software without specific prior written permission.
17#
18# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28#
29
30"""
31FAT creator
32"""
33
34import sys
35import os
36import random
37import xstruct
38import array
39
40exclude_names = set(['.svn', '.bzr'])
41
42def align_up(size, alignment):
43 "Return size aligned up to alignment"
44
45 if (size % alignment == 0):
46 return size
47
48 return ((size // alignment) + 1) * alignment
49
50def subtree_size(root, cluster_size, dirent_size):
51 "Recursive directory walk and calculate size"
52
53 size = 0
54 files = 2
55
56 for name in os.listdir(root):
57 canon = os.path.join(root, name)
58
59 if (os.path.isfile(canon) and (not name in exclude_names)):
60 size += align_up(os.path.getsize(canon), cluster_size)
61 files += 1
62
63 if (os.path.isdir(canon) and (not name in exclude_names)):
64 size += subtree_size(canon, cluster_size, dirent_size)
65 files += 1
66
67 return size + align_up(files * dirent_size, cluster_size)
68
69def root_entries(root):
70 "Return number of root directory entries"
71
72 return len(os.listdir(root))
73
74def write_file(path, outf, cluster_size, data_start, fat, reserved_clusters):
75 "Store the contents of a file"
76
77 size = os.path.getsize(path)
78 prev = -1
79 first = 0
80
81 inf = open(path, "rb")
82 rd = 0;
83 while (rd < size):
84 empty_cluster = fat.index(0)
85 fat[empty_cluster] = 0xffff
86
87 if (prev != -1):
88 fat[prev] = empty_cluster
89 else:
90 first = empty_cluster
91
92 prev = empty_cluster
93
94 data = bytes(inf.read(cluster_size));
95 outf.seek(data_start + (empty_cluster - reserved_clusters) * cluster_size)
96 outf.write(data)
97 rd += len(data)
98 inf.close()
99
100 return first, size
101
102def write_directory(directory, outf, cluster_size, data_start, fat, reserved_clusters, dirent_size, empty_cluster):
103 "Store the contents of a directory"
104
105 length = len(directory)
106 size = length * dirent_size
107 prev = -1
108 first = 0
109
110 i = 0
111 rd = 0;
112 while (rd < size):
113 if (prev != -1):
114 empty_cluster = fat.index(0)
115 fat[empty_cluster] = 0xffff
116 fat[prev] = empty_cluster
117 else:
118 first = empty_cluster
119
120 prev = empty_cluster
121
122 data = bytes()
123 data_len = 0
124 while ((i < length) and (data_len < cluster_size)):
125 if (i == 0):
126 directory[i].cluster = empty_cluster
127
128 data += directory[i].pack()
129 data_len += dirent_size
130 i += 1
131
132 outf.seek(data_start + (empty_cluster - reserved_clusters) * cluster_size)
133 outf.write(data)
134 rd += len(data)
135
136 return first, size
137
138DIR_ENTRY = """little:
139 char name[8] /* file name */
140 char ext[3] /* file extension */
141 uint8_t attr /* file attributes */
142 uint8_t lcase /* file name case (NT extension) */
143 uint8_t ctime_fine /* create time (fine resolution) */
144 uint16_t ctime /* create time */
145 uint16_t cdate /* create date */
146 uint16_t adate /* access date */
147 padding[2] /* EA-index */
148 uint16_t mtime /* modification time */
149 uint16_t mdate /* modification date */
150 uint16_t cluster /* first cluster */
151 uint32_t size /* file size */
152"""
153
154DOT_DIR_ENTRY = """little:
155 uint8_t signature /* 0x2e signature */
156 char name[7] /* empty */
157 char ext[3] /* empty */
158 uint8_t attr /* file attributes */
159 padding[1] /* reserved for NT */
160 uint8_t ctime_fine /* create time (fine resolution) */
161 uint16_t ctime /* create time */
162 uint16_t cdate /* create date */
163 uint16_t adate /* access date */
164 padding[2] /* EA-index */
165 uint16_t mtime /* modification time */
166 uint16_t mdate /* modification date */
167 uint16_t cluster /* first cluster */
168 uint32_t size /* file size */
169"""
170
171DOTDOT_DIR_ENTRY = """little:
172 uint8_t signature[2] /* 0x2e signature */
173 char name[6] /* empty */
174 char ext[3] /* empty */
175 uint8_t attr /* file attributes */
176 padding[1] /* reserved for NT */
177 uint8_t ctime_fine /* create time (fine resolution) */
178 uint16_t ctime /* create time */
179 uint16_t cdate /* create date */
180 uint16_t adate /* access date */
181 padding[2] /* EA-index */
182 uint16_t mtime /* modification time */
183 uint16_t mdate /* modification date */
184 uint16_t cluster /* first cluster */
185 uint32_t size /* file size */
186"""
187
188def mangle_fname(name):
189 # FIXME: filter illegal characters
190 parts = name.split('.')
191
192 if (len(parts) > 0):
193 fname = parts[0]
194 else:
195 fname = ''
196
197 return (fname + ' ').upper()[0:8]
198
199def mangle_ext(name):
200 # FIXME: filter illegal characters
201 parts = name.split('.')
202
203 if (len(parts) > 1):
204 ext = parts[1]
205 else:
206 ext = ''
207
208 return (ext + ' ').upper()[0:3]
209
210def create_dirent(name, directory, cluster, size):
211 dir_entry = xstruct.create(DIR_ENTRY)
212
213 dir_entry.name = mangle_fname(name)
214 dir_entry.ext = mangle_ext(name)
215
216 if (directory):
217 dir_entry.attr = 0x30
218 else:
219 dir_entry.attr = 0x20
220
221 dir_entry.lcase = 0x18
222 dir_entry.ctime_fine = 0 # FIXME
223 dir_entry.ctime = 0 # FIXME
224 dir_entry.cdate = 0 # FIXME
225 dir_entry.adate = 0 # FIXME
226 dir_entry.mtime = 0 # FIXME
227 dir_entry.mdate = 0 # FIXME
228 dir_entry.cluster = cluster
229
230 if (directory):
231 dir_entry.size = 0
232 else:
233 dir_entry.size = size
234
235 return dir_entry
236
237def create_dot_dirent(empty_cluster):
238 dir_entry = xstruct.create(DOT_DIR_ENTRY)
239
240 dir_entry.signature = 0x2e
241 dir_entry.name = ' '
242 dir_entry.ext = ' '
243 dir_entry.attr = 0x10
244
245 dir_entry.ctime_fine = 0 # FIXME
246 dir_entry.ctime = 0 # FIXME
247 dir_entry.cdate = 0 # FIXME
248 dir_entry.adate = 0 # FIXME
249 dir_entry.mtime = 0 # FIXME
250 dir_entry.mdate = 0 # FIXME
251 dir_entry.cluster = empty_cluster
252 dir_entry.size = 0
253
254 return dir_entry
255
256def create_dotdot_dirent(parent_cluster):
257 dir_entry = xstruct.create(DOTDOT_DIR_ENTRY)
258
259 dir_entry.signature = [0x2e, 0x2e]
260 dir_entry.name = ' '
261 dir_entry.ext = ' '
262 dir_entry.attr = 0x10
263
264 dir_entry.ctime_fine = 0 # FIXME
265 dir_entry.ctime = 0 # FIXME
266 dir_entry.cdate = 0 # FIXME
267 dir_entry.adate = 0 # FIXME
268 dir_entry.mtime = 0 # FIXME
269 dir_entry.mdate = 0 # FIXME
270 dir_entry.cluster = parent_cluster
271 dir_entry.size = 0
272
273 return dir_entry
274
275def recursion(head, root, outf, cluster_size, root_start, data_start, fat, reserved_clusters, dirent_size, parent_cluster):
276 "Recursive directory walk"
277
278 directory = []
279
280 if (not head):
281 # Directory cluster preallocation
282 empty_cluster = fat.index(0)
283 fat[empty_cluster] = 0xffff
284
285 directory.append(create_dot_dirent(empty_cluster))
286 directory.append(create_dotdot_dirent(parent_cluster))
287 else:
288 empty_cluster = 0
289
290 for name in os.listdir(root):
291 canon = os.path.join(root, name)
292
293 if (os.path.isfile(canon) and (not name in exclude_names)):
294 rv = write_file(canon, outf, cluster_size, data_start, fat, reserved_clusters)
295 directory.append(create_dirent(name, False, rv[0], rv[1]))
296
297 if (os.path.isdir(canon) and (not name in exclude_names)):
298 rv = recursion(False, canon, outf, cluster_size, root_start, data_start, fat, reserved_clusters, dirent_size, empty_cluster)
299 directory.append(create_dirent(name, True, rv[0], rv[1]))
300
301 if (head):
302 outf.seek(root_start)
303 for dir_entry in directory:
304 outf.write(dir_entry.pack())
305 else:
306 return write_directory(directory, outf, cluster_size, data_start, fat, reserved_clusters, dirent_size, empty_cluster)
307
308BOOT_SECTOR = """little:
309 uint8_t jmp[3] /* jump instruction */
310 char oem[8] /* OEM string */
311 uint16_t sector /* bytes per sector */
312 uint8_t cluster /* sectors per cluster */
313 uint16_t reserved /* reserved sectors */
314 uint8_t fats /* number of FATs */
315 uint16_t rootdir /* root directory entries */
316 uint16_t sectors /* total number of sectors */
317 uint8_t descriptor /* media descriptor */
318 uint16_t fat_sectors /* sectors per single FAT */
319 uint16_t track_sectors /* sectors per track */
320 uint16_t heads /* number of heads */
321 uint32_t hidden /* hidden sectors */
322 uint32_t sectors_big /* total number of sectors (if sectors == 0) */
323
324 /* Extended BIOS Parameter Block */
325 uint8_t drive /* physical drive number */
326 padding[1] /* reserved (current head) */
327 uint8_t extboot_signature /* extended boot signature */
328 uint32_t serial /* serial number */
329 char label[11] /* volume label */
330 char fstype[8] /* filesystem type */
331 padding[448] /* boot code */
332 uint8_t boot_signature[2] /* boot signature */
333"""
334
335EMPTY_SECTOR = """little:
336 padding[512] /* empty sector data */
337"""
338
339FAT_ENTRY = """little:
340 uint16_t next /* FAT16 entry */
341"""
342
343def usage(prname):
344 "Print usage syntax"
345 print(prname + " <EXTRA_BYTES> <PATH> <IMAGE>")
346
347def main():
348 if (len(sys.argv) < 4):
349 usage(sys.argv[0])
350 return
351
352 if (not sys.argv[1].isdigit()):
353 print("<EXTRA_BYTES> must be a number")
354 return
355
356 extra_bytes = int(sys.argv[1])
357
358 path = os.path.abspath(sys.argv[2])
359 if (not os.path.isdir(path)):
360 print("<PATH> must be a directory")
361 return
362
363 fat16_clusters = 4096
364
365 sector_size = 512
366 cluster_size = 4096
367 dirent_size = 32
368 fatent_size = 2
369 fat_count = 2
370 reserved_clusters = 2
371
372 # Make sure the filesystem is large enought for FAT16
373 size = subtree_size(path, cluster_size, dirent_size) + reserved_clusters * cluster_size + extra_bytes
374 while (size // cluster_size < fat16_clusters):
375 if (cluster_size > sector_size):
376 cluster_size = cluster_size // 2
377 size = subtree_size(path, cluster_size, dirent_size) + reserved_clusters * cluster_size + extra_bytes
378 else:
379 size = fat16_clusters * cluster_size + reserved_clusters * cluster_size
380
381 root_size = align_up(root_entries(path) * dirent_size, cluster_size)
382
383 fat_size = align_up(align_up(size, cluster_size) // cluster_size * fatent_size, sector_size)
384
385 sectors = (cluster_size + fat_count * fat_size + root_size + size) // sector_size
386 root_start = cluster_size + fat_count * fat_size
387 data_start = root_start + root_size
388
389 outf = open(sys.argv[3], "wb")
390
391 boot_sector = xstruct.create(BOOT_SECTOR)
392 boot_sector.jmp = [0xEB, 0x3C, 0x90]
393 boot_sector.oem = b'MSDOS5.0'
394 boot_sector.sector = sector_size
395 boot_sector.cluster = cluster_size // sector_size
396 boot_sector.reserved = cluster_size // sector_size
397 boot_sector.fats = fat_count
398 boot_sector.rootdir = root_size // dirent_size
399 if (sectors <= 65535):
400 boot_sector.sectors = sectors
401 else:
402 boot_sector.sectors = 0
403 boot_sector.descriptor = 0xF8
404 boot_sector.fat_sectors = fat_size // sector_size
405 boot_sector.track_sectors = 63
406 boot_sector.heads = 6
407 boot_sector.hidden = 0
408 if (sectors > 65535):
409 boot_sector.sectors_big = sectors
410 else:
411 boot_sector.sectors_big = 0
412
413 boot_sector.drive = 0x80
414 boot_sector.extboot_signature = 0x29
415 boot_sector.serial = random.randint(0, 0x7fffffff)
416 boot_sector.label = b'HELENOS'
417 boot_sector.fstype = b'FAT16 '
418 boot_sector.boot_signature = [0x55, 0xAA]
419
420 outf.write(boot_sector.pack())
421
422 empty_sector = xstruct.create(EMPTY_SECTOR)
423
424 # Reserved sectors
425 for i in range(1, cluster_size // sector_size):
426 outf.write(empty_sector.pack())
427
428 # FAT tables
429 for i in range(0, fat_count):
430 for j in range(0, fat_size // sector_size):
431 outf.write(empty_sector.pack())
432
433 # Root directory
434 for i in range(0, root_size // sector_size):
435 outf.write(empty_sector.pack())
436
437 # Data
438 for i in range(0, size // sector_size):
439 outf.write(empty_sector.pack())
440
441 fat = array.array('L', [0] * (fat_size // fatent_size))
442 fat[0] = 0xfff8
443 fat[1] = 0xffff
444
445 recursion(True, path, outf, cluster_size, root_start, data_start, fat, reserved_clusters, dirent_size, 0)
446
447 # Store FAT
448 fat_entry = xstruct.create(FAT_ENTRY)
449 for i in range(0, fat_count):
450 outf.seek(cluster_size + i * fat_size)
451 for j in range(0, fat_size // fatent_size):
452 fat_entry.next = fat[j]
453 outf.write(fat_entry.pack())
454
455 outf.close()
456
457if __name__ == '__main__':
458 main()
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