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1 | /* | |
2 | * Read flash partition table from command line | |
3 | * | |
4 | * Copyright © 2002 SYSGO Real-Time Solutions GmbH | |
5 | * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | * | |
21 | * The format for the command line is as follows: | |
22 | * | |
23 | * mtdparts=<mtddef>[;<mtddef] | |
24 | * <mtddef> := <mtd-id>:<partdef>[,<partdef>] | |
25 | * <partdef> := <size>[@<offset>][<name>][ro][lk] | |
26 | * <mtd-id> := unique name used in mapping driver/device (mtd->name) | |
27 | * <size> := standard linux memsize OR "-" to denote all remaining space | |
28 | * size is automatically truncated at end of device | |
29 | * if specified or trucated size is 0 the part is skipped | |
30 | * <offset> := standard linux memsize | |
31 | * if omitted the part will immediately follow the previous part | |
32 | * or 0 if the first part | |
33 | * <name> := '(' NAME ')' | |
34 | * NAME will appear in /proc/mtd | |
35 | * | |
36 | * <size> and <offset> can be specified such that the parts are out of order | |
37 | * in physical memory and may even overlap. | |
38 | * | |
39 | * The parts are assigned MTD numbers in the order they are specified in the | |
40 | * command line regardless of their order in physical memory. | |
41 | * | |
42 | * Examples: | |
43 | * | |
44 | * 1 NOR Flash, with 1 single writable partition: | |
45 | * edb7312-nor:- | |
46 | * | |
47 | * 1 NOR Flash with 2 partitions, 1 NAND with one | |
48 | * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home) | |
49 | */ | |
50 | ||
51 | #include <linux/kernel.h> | |
52 | #include <linux/slab.h> | |
53 | #include <linux/mtd/mtd.h> | |
54 | #include <linux/mtd/partitions.h> | |
55 | #include <linux/module.h> | |
56 | #include <linux/err.h> | |
57 | ||
58 | /* error message prefix */ | |
59 | #define ERRP "mtd: " | |
60 | ||
61 | /* debug macro */ | |
62 | #if 0 | |
63 | #define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0) | |
64 | #else | |
65 | #define dbg(x) | |
66 | #endif | |
67 | ||
68 | ||
69 | /* special size referring to all the remaining space in a partition */ | |
70 | #define SIZE_REMAINING ULLONG_MAX | |
71 | #define OFFSET_CONTINUOUS ULLONG_MAX | |
72 | ||
73 | struct cmdline_mtd_partition { | |
74 | struct cmdline_mtd_partition *next; | |
75 | char *mtd_id; | |
76 | int num_parts; | |
77 | struct mtd_partition *parts; | |
78 | }; | |
79 | ||
80 | /* mtdpart_setup() parses into here */ | |
81 | static struct cmdline_mtd_partition *partitions; | |
82 | ||
83 | /* the command line passed to mtdpart_setup() */ | |
84 | static char *mtdparts; | |
85 | static char *cmdline; | |
86 | static int cmdline_parsed; | |
87 | ||
88 | /* | |
89 | * Parse one partition definition for an MTD. Since there can be many | |
90 | * comma separated partition definitions, this function calls itself | |
91 | * recursively until no more partition definitions are found. Nice side | |
92 | * effect: the memory to keep the mtd_partition structs and the names | |
93 | * is allocated upon the last definition being found. At that point the | |
94 | * syntax has been verified ok. | |
95 | */ | |
96 | static struct mtd_partition * newpart(char *s, | |
97 | char **retptr, | |
98 | int *num_parts, | |
99 | int this_part, | |
100 | unsigned char **extra_mem_ptr, | |
101 | int extra_mem_size) | |
102 | { | |
103 | struct mtd_partition *parts; | |
104 | unsigned long long size, offset = OFFSET_CONTINUOUS; | |
105 | char *name; | |
106 | int name_len; | |
107 | unsigned char *extra_mem; | |
108 | char delim; | |
109 | unsigned int mask_flags; | |
110 | ||
111 | /* fetch the partition size */ | |
112 | if (*s == '-') { | |
113 | /* assign all remaining space to this partition */ | |
114 | size = SIZE_REMAINING; | |
115 | s++; | |
116 | } else { | |
117 | size = memparse(s, &s); | |
118 | if (size < PAGE_SIZE) { | |
119 | printk(KERN_ERR ERRP "partition size too small (%llx)\n", | |
120 | size); | |
121 | return ERR_PTR(-EINVAL); | |
122 | } | |
123 | } | |
124 | ||
125 | /* fetch partition name and flags */ | |
126 | mask_flags = 0; /* this is going to be a regular partition */ | |
127 | delim = 0; | |
128 | ||
129 | /* check for offset */ | |
130 | if (*s == '@') { | |
131 | s++; | |
132 | offset = memparse(s, &s); | |
133 | } | |
134 | ||
135 | /* now look for name */ | |
136 | if (*s == '(') | |
137 | delim = ')'; | |
138 | ||
139 | if (delim) { | |
140 | char *p; | |
141 | ||
142 | name = ++s; | |
143 | p = strchr(name, delim); | |
144 | if (!p) { | |
145 | printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim); | |
146 | return ERR_PTR(-EINVAL); | |
147 | } | |
148 | name_len = p - name; | |
149 | s = p + 1; | |
150 | } else { | |
151 | name = NULL; | |
152 | name_len = 13; /* Partition_000 */ | |
153 | } | |
154 | ||
155 | /* record name length for memory allocation later */ | |
156 | extra_mem_size += name_len + 1; | |
157 | ||
158 | /* test for options */ | |
159 | if (strncmp(s, "ro", 2) == 0) { | |
160 | mask_flags |= MTD_WRITEABLE; | |
161 | s += 2; | |
162 | } | |
163 | ||
164 | /* if lk is found do NOT unlock the MTD partition*/ | |
165 | if (strncmp(s, "lk", 2) == 0) { | |
166 | mask_flags |= MTD_POWERUP_LOCK; | |
167 | s += 2; | |
168 | } | |
169 | ||
170 | /* test if more partitions are following */ | |
171 | if (*s == ',') { | |
172 | if (size == SIZE_REMAINING) { | |
173 | printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n"); | |
174 | return ERR_PTR(-EINVAL); | |
175 | } | |
176 | /* more partitions follow, parse them */ | |
177 | parts = newpart(s + 1, &s, num_parts, this_part + 1, | |
178 | &extra_mem, extra_mem_size); | |
179 | if (IS_ERR(parts)) | |
180 | return parts; | |
181 | } else { | |
182 | /* this is the last partition: allocate space for all */ | |
183 | int alloc_size; | |
184 | ||
185 | *num_parts = this_part + 1; | |
186 | alloc_size = *num_parts * sizeof(struct mtd_partition) + | |
187 | extra_mem_size; | |
188 | ||
189 | parts = kzalloc(alloc_size, GFP_KERNEL); | |
190 | if (!parts) | |
191 | return ERR_PTR(-ENOMEM); | |
192 | extra_mem = (unsigned char *)(parts + *num_parts); | |
193 | } | |
194 | ||
195 | /* enter this partition (offset will be calculated later if it is zero at this point) */ | |
196 | parts[this_part].size = size; | |
197 | parts[this_part].offset = offset; | |
198 | parts[this_part].mask_flags = mask_flags; | |
199 | if (name) | |
200 | strlcpy(extra_mem, name, name_len + 1); | |
201 | else | |
202 | sprintf(extra_mem, "Partition_%03d", this_part); | |
203 | parts[this_part].name = extra_mem; | |
204 | extra_mem += name_len + 1; | |
205 | ||
206 | dbg(("partition %d: name <%s>, offset %llx, size %llx, mask flags %x\n", | |
207 | this_part, parts[this_part].name, parts[this_part].offset, | |
208 | parts[this_part].size, parts[this_part].mask_flags)); | |
209 | ||
210 | /* return (updated) pointer to extra_mem memory */ | |
211 | if (extra_mem_ptr) | |
212 | *extra_mem_ptr = extra_mem; | |
213 | ||
214 | /* return (updated) pointer command line string */ | |
215 | *retptr = s; | |
216 | ||
217 | /* return partition table */ | |
218 | return parts; | |
219 | } | |
220 | ||
221 | /* | |
222 | * Parse the command line. | |
223 | */ | |
224 | static int mtdpart_setup_real(char *s) | |
225 | { | |
226 | cmdline_parsed = 1; | |
227 | ||
228 | for( ; s != NULL; ) | |
229 | { | |
230 | struct cmdline_mtd_partition *this_mtd; | |
231 | struct mtd_partition *parts; | |
232 | int mtd_id_len, num_parts; | |
233 | char *p, *mtd_id; | |
234 | ||
235 | mtd_id = s; | |
236 | ||
237 | /* fetch <mtd-id> */ | |
238 | p = strchr(s, ':'); | |
239 | if (!p) { | |
240 | printk(KERN_ERR ERRP "no mtd-id\n"); | |
241 | return -EINVAL; | |
242 | } | |
243 | mtd_id_len = p - mtd_id; | |
244 | ||
245 | dbg(("parsing <%s>\n", p+1)); | |
246 | ||
247 | /* | |
248 | * parse one mtd. have it reserve memory for the | |
249 | * struct cmdline_mtd_partition and the mtd-id string. | |
250 | */ | |
251 | parts = newpart(p + 1, /* cmdline */ | |
252 | &s, /* out: updated cmdline ptr */ | |
253 | &num_parts, /* out: number of parts */ | |
254 | 0, /* first partition */ | |
255 | (unsigned char**)&this_mtd, /* out: extra mem */ | |
256 | mtd_id_len + 1 + sizeof(*this_mtd) + | |
257 | sizeof(void*)-1 /*alignment*/); | |
258 | if (IS_ERR(parts)) { | |
259 | /* | |
260 | * An error occurred. We're either: | |
261 | * a) out of memory, or | |
262 | * b) in the middle of the partition spec | |
263 | * Either way, this mtd is hosed and we're | |
264 | * unlikely to succeed in parsing any more | |
265 | */ | |
266 | return PTR_ERR(parts); | |
267 | } | |
268 | ||
269 | /* align this_mtd */ | |
270 | this_mtd = (struct cmdline_mtd_partition *) | |
271 | ALIGN((unsigned long)this_mtd, sizeof(void *)); | |
272 | /* enter results */ | |
273 | this_mtd->parts = parts; | |
274 | this_mtd->num_parts = num_parts; | |
275 | this_mtd->mtd_id = (char*)(this_mtd + 1); | |
276 | strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1); | |
277 | ||
278 | /* link into chain */ | |
279 | this_mtd->next = partitions; | |
280 | partitions = this_mtd; | |
281 | ||
282 | dbg(("mtdid=<%s> num_parts=<%d>\n", | |
283 | this_mtd->mtd_id, this_mtd->num_parts)); | |
284 | ||
285 | ||
286 | /* EOS - we're done */ | |
287 | if (*s == 0) | |
288 | break; | |
289 | ||
290 | /* does another spec follow? */ | |
291 | if (*s != ';') { | |
292 | printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s); | |
293 | return -EINVAL; | |
294 | } | |
295 | s++; | |
296 | } | |
297 | ||
298 | return 0; | |
299 | } | |
300 | ||
301 | /* | |
302 | * Main function to be called from the MTD mapping driver/device to | |
303 | * obtain the partitioning information. At this point the command line | |
304 | * arguments will actually be parsed and turned to struct mtd_partition | |
305 | * information. It returns partitions for the requested mtd device, or | |
306 | * the first one in the chain if a NULL mtd_id is passed in. | |
307 | */ | |
308 | static int parse_cmdline_partitions(struct mtd_info *master, | |
309 | struct mtd_partition **pparts, | |
310 | struct mtd_part_parser_data *data) | |
311 | { | |
312 | unsigned long long offset; | |
313 | int i, err; | |
314 | struct cmdline_mtd_partition *part; | |
315 | const char *mtd_id = master->name; | |
316 | ||
317 | /* parse command line */ | |
318 | if (!cmdline_parsed) { | |
319 | err = mtdpart_setup_real(cmdline); | |
320 | if (err) | |
321 | return err; | |
322 | } | |
323 | ||
324 | /* | |
325 | * Search for the partition definition matching master->name. | |
326 | * If master->name is not set, stop at first partition definition. | |
327 | */ | |
328 | for (part = partitions; part; part = part->next) { | |
329 | if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id))) | |
330 | break; | |
331 | } | |
332 | ||
333 | if (!part) | |
334 | return 0; | |
335 | ||
336 | for (i = 0, offset = 0; i < part->num_parts; i++) { | |
337 | if (part->parts[i].offset == OFFSET_CONTINUOUS) | |
338 | part->parts[i].offset = offset; | |
339 | else | |
340 | offset = part->parts[i].offset; | |
341 | ||
342 | if (part->parts[i].size == SIZE_REMAINING) | |
343 | part->parts[i].size = master->size - offset; | |
344 | ||
345 | if (offset + part->parts[i].size > master->size) { | |
346 | printk(KERN_WARNING ERRP | |
347 | "%s: partitioning exceeds flash size, truncating\n", | |
348 | part->mtd_id); | |
349 | part->parts[i].size = master->size - offset; | |
350 | } | |
351 | offset += part->parts[i].size; | |
352 | ||
353 | if (part->parts[i].size == 0) { | |
354 | printk(KERN_WARNING ERRP | |
355 | "%s: skipping zero sized partition\n", | |
356 | part->mtd_id); | |
357 | part->num_parts--; | |
358 | memmove(&part->parts[i], &part->parts[i + 1], | |
359 | sizeof(*part->parts) * (part->num_parts - i)); | |
360 | i--; | |
361 | } | |
362 | } | |
363 | ||
364 | *pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts, | |
365 | GFP_KERNEL); | |
366 | if (!*pparts) | |
367 | return -ENOMEM; | |
368 | ||
369 | return part->num_parts; | |
370 | } | |
371 | ||
372 | ||
373 | /* | |
374 | * This is the handler for our kernel parameter, called from | |
375 | * main.c::checksetup(). Note that we can not yet kmalloc() anything, | |
376 | * so we only save the commandline for later processing. | |
377 | * | |
378 | * This function needs to be visible for bootloaders. | |
379 | */ | |
380 | static int __init mtdpart_setup(char *s) | |
381 | { | |
382 | cmdline = s; | |
383 | return 1; | |
384 | } | |
385 | ||
386 | __setup("mtdparts=", mtdpart_setup); | |
387 | ||
388 | static struct mtd_part_parser cmdline_parser = { | |
389 | .owner = THIS_MODULE, | |
390 | .parse_fn = parse_cmdline_partitions, | |
391 | .name = "cmdlinepart", | |
392 | }; | |
393 | ||
394 | static int __init cmdline_parser_init(void) | |
395 | { | |
396 | if (mtdparts) | |
397 | mtdpart_setup(mtdparts); | |
398 | return register_mtd_parser(&cmdline_parser); | |
399 | } | |
400 | ||
401 | static void __exit cmdline_parser_exit(void) | |
402 | { | |
403 | deregister_mtd_parser(&cmdline_parser); | |
404 | } | |
405 | ||
406 | module_init(cmdline_parser_init); | |
407 | module_exit(cmdline_parser_exit); | |
408 | ||
409 | MODULE_PARM_DESC(mtdparts, "Partitioning specification"); | |
410 | module_param(mtdparts, charp, 0); | |
411 | ||
412 | MODULE_LICENSE("GPL"); | |
413 | MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>"); | |
414 | MODULE_DESCRIPTION("Command line configuration of MTD partitions"); |