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1da177e4 LT |
1 | /* |
2 | * $Id: cmdlinepart.c,v 1.17 2004/11/26 11:18:47 lavinen Exp $ | |
3 | * | |
4 | * Read flash partition table from command line | |
5 | * | |
6 | * Copyright 2002 SYSGO Real-Time Solutions GmbH | |
7 | * | |
8 | * The format for the command line is as follows: | |
9 | * | |
10 | * mtdparts=<mtddef>[;<mtddef] | |
11 | * <mtddef> := <mtd-id>:<partdef>[,<partdef>] | |
12 | * <partdef> := <size>[@offset][<name>][ro] | |
13 | * <mtd-id> := unique name used in mapping driver/device (mtd->name) | |
14 | * <size> := standard linux memsize OR "-" to denote all remaining space | |
15 | * <name> := '(' NAME ')' | |
16 | * | |
17 | * Examples: | |
18 | * | |
19 | * 1 NOR Flash, with 1 single writable partition: | |
20 | * edb7312-nor:- | |
21 | * | |
22 | * 1 NOR Flash with 2 partitions, 1 NAND with one | |
23 | * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home) | |
24 | */ | |
25 | ||
26 | #include <linux/kernel.h> | |
27 | #include <linux/slab.h> | |
28 | ||
29 | #include <linux/mtd/mtd.h> | |
30 | #include <linux/mtd/partitions.h> | |
31 | #include <linux/bootmem.h> | |
32 | ||
33 | /* error message prefix */ | |
34 | #define ERRP "mtd: " | |
35 | ||
36 | /* debug macro */ | |
37 | #if 0 | |
38 | #define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0) | |
39 | #else | |
40 | #define dbg(x) | |
41 | #endif | |
42 | ||
43 | ||
44 | /* special size referring to all the remaining space in a partition */ | |
45 | #define SIZE_REMAINING 0xffffffff | |
46 | ||
47 | struct cmdline_mtd_partition { | |
48 | struct cmdline_mtd_partition *next; | |
49 | char *mtd_id; | |
50 | int num_parts; | |
51 | struct mtd_partition *parts; | |
52 | }; | |
53 | ||
54 | /* mtdpart_setup() parses into here */ | |
55 | static struct cmdline_mtd_partition *partitions; | |
56 | ||
57 | /* the command line passed to mtdpart_setupd() */ | |
58 | static char *cmdline; | |
59 | static int cmdline_parsed = 0; | |
60 | ||
61 | /* | |
62 | * Parse one partition definition for an MTD. Since there can be many | |
63 | * comma separated partition definitions, this function calls itself | |
64 | * recursively until no more partition definitions are found. Nice side | |
65 | * effect: the memory to keep the mtd_partition structs and the names | |
66 | * is allocated upon the last definition being found. At that point the | |
67 | * syntax has been verified ok. | |
68 | */ | |
69 | static struct mtd_partition * newpart(char *s, | |
70 | char **retptr, | |
71 | int *num_parts, | |
72 | int this_part, | |
73 | unsigned char **extra_mem_ptr, | |
74 | int extra_mem_size) | |
75 | { | |
76 | struct mtd_partition *parts; | |
77 | unsigned long size; | |
78 | unsigned long offset = 0; | |
79 | char *name; | |
80 | int name_len; | |
81 | unsigned char *extra_mem; | |
82 | char delim; | |
83 | unsigned int mask_flags; | |
84 | ||
85 | /* fetch the partition size */ | |
86 | if (*s == '-') | |
87 | { /* assign all remaining space to this partition */ | |
88 | size = SIZE_REMAINING; | |
89 | s++; | |
90 | } | |
91 | else | |
92 | { | |
93 | size = memparse(s, &s); | |
94 | if (size < PAGE_SIZE) | |
95 | { | |
96 | printk(KERN_ERR ERRP "partition size too small (%lx)\n", size); | |
97 | return NULL; | |
98 | } | |
99 | } | |
100 | ||
101 | /* fetch partition name and flags */ | |
102 | mask_flags = 0; /* this is going to be a regular partition */ | |
103 | delim = 0; | |
104 | /* check for offset */ | |
105 | if (*s == '@') | |
106 | { | |
107 | s++; | |
108 | offset = memparse(s, &s); | |
109 | } | |
110 | /* now look for name */ | |
111 | if (*s == '(') | |
112 | { | |
113 | delim = ')'; | |
114 | } | |
115 | ||
116 | if (delim) | |
117 | { | |
118 | char *p; | |
119 | ||
120 | name = ++s; | |
121 | if ((p = strchr(name, delim)) == 0) | |
122 | { | |
123 | printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim); | |
124 | return NULL; | |
125 | } | |
126 | name_len = p - name; | |
127 | s = p + 1; | |
128 | } | |
129 | else | |
130 | { | |
131 | name = NULL; | |
132 | name_len = 13; /* Partition_000 */ | |
133 | } | |
134 | ||
135 | /* record name length for memory allocation later */ | |
136 | extra_mem_size += name_len + 1; | |
137 | ||
138 | /* test for options */ | |
139 | if (strncmp(s, "ro", 2) == 0) | |
140 | { | |
141 | mask_flags |= MTD_WRITEABLE; | |
142 | s += 2; | |
143 | } | |
144 | ||
145 | /* test if more partitions are following */ | |
146 | if (*s == ',') | |
147 | { | |
148 | if (size == SIZE_REMAINING) | |
149 | { | |
150 | printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n"); | |
151 | return NULL; | |
152 | } | |
153 | /* more partitions follow, parse them */ | |
154 | if ((parts = newpart(s + 1, &s, num_parts, | |
155 | this_part + 1, &extra_mem, extra_mem_size)) == 0) | |
156 | return NULL; | |
157 | } | |
158 | else | |
159 | { /* this is the last partition: allocate space for all */ | |
160 | int alloc_size; | |
161 | ||
162 | *num_parts = this_part + 1; | |
163 | alloc_size = *num_parts * sizeof(struct mtd_partition) + | |
164 | extra_mem_size; | |
165 | parts = kmalloc(alloc_size, GFP_KERNEL); | |
166 | if (!parts) | |
167 | { | |
168 | printk(KERN_ERR ERRP "out of memory\n"); | |
169 | return NULL; | |
170 | } | |
171 | memset(parts, 0, alloc_size); | |
172 | extra_mem = (unsigned char *)(parts + *num_parts); | |
173 | } | |
174 | /* enter this partition (offset will be calculated later if it is zero at this point) */ | |
175 | parts[this_part].size = size; | |
176 | parts[this_part].offset = offset; | |
177 | parts[this_part].mask_flags = mask_flags; | |
178 | if (name) | |
179 | { | |
180 | strlcpy(extra_mem, name, name_len + 1); | |
181 | } | |
182 | else | |
183 | { | |
184 | sprintf(extra_mem, "Partition_%03d", this_part); | |
185 | } | |
186 | parts[this_part].name = extra_mem; | |
187 | extra_mem += name_len + 1; | |
188 | ||
189 | dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n", | |
190 | this_part, | |
191 | parts[this_part].name, | |
192 | parts[this_part].offset, | |
193 | parts[this_part].size, | |
194 | parts[this_part].mask_flags)); | |
195 | ||
196 | /* return (updated) pointer to extra_mem memory */ | |
197 | if (extra_mem_ptr) | |
198 | *extra_mem_ptr = extra_mem; | |
199 | ||
200 | /* return (updated) pointer command line string */ | |
201 | *retptr = s; | |
202 | ||
203 | /* return partition table */ | |
204 | return parts; | |
205 | } | |
206 | ||
207 | /* | |
208 | * Parse the command line. | |
209 | */ | |
210 | static int mtdpart_setup_real(char *s) | |
211 | { | |
212 | cmdline_parsed = 1; | |
213 | ||
214 | for( ; s != NULL; ) | |
215 | { | |
216 | struct cmdline_mtd_partition *this_mtd; | |
217 | struct mtd_partition *parts; | |
218 | int mtd_id_len; | |
219 | int num_parts; | |
220 | char *p, *mtd_id; | |
221 | ||
222 | mtd_id = s; | |
223 | /* fetch <mtd-id> */ | |
224 | if (!(p = strchr(s, ':'))) | |
225 | { | |
226 | printk(KERN_ERR ERRP "no mtd-id\n"); | |
227 | return 0; | |
228 | } | |
229 | mtd_id_len = p - mtd_id; | |
230 | ||
231 | dbg(("parsing <%s>\n", p+1)); | |
232 | ||
233 | /* | |
234 | * parse one mtd. have it reserve memory for the | |
235 | * struct cmdline_mtd_partition and the mtd-id string. | |
236 | */ | |
237 | parts = newpart(p + 1, /* cmdline */ | |
238 | &s, /* out: updated cmdline ptr */ | |
239 | &num_parts, /* out: number of parts */ | |
240 | 0, /* first partition */ | |
241 | (unsigned char**)&this_mtd, /* out: extra mem */ | |
242 | mtd_id_len + 1 + sizeof(*this_mtd)); | |
243 | if(!parts) | |
244 | { | |
245 | /* | |
246 | * An error occurred. We're either: | |
247 | * a) out of memory, or | |
248 | * b) in the middle of the partition spec | |
249 | * Either way, this mtd is hosed and we're | |
250 | * unlikely to succeed in parsing any more | |
251 | */ | |
252 | return 0; | |
253 | } | |
254 | ||
255 | /* enter results */ | |
256 | this_mtd->parts = parts; | |
257 | this_mtd->num_parts = num_parts; | |
258 | this_mtd->mtd_id = (char*)(this_mtd + 1); | |
259 | strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1); | |
260 | ||
261 | /* link into chain */ | |
262 | this_mtd->next = partitions; | |
263 | partitions = this_mtd; | |
264 | ||
265 | dbg(("mtdid=<%s> num_parts=<%d>\n", | |
266 | this_mtd->mtd_id, this_mtd->num_parts)); | |
267 | ||
268 | ||
269 | /* EOS - we're done */ | |
270 | if (*s == 0) | |
271 | break; | |
272 | ||
273 | /* does another spec follow? */ | |
274 | if (*s != ';') | |
275 | { | |
276 | printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s); | |
277 | return 0; | |
278 | } | |
279 | s++; | |
280 | } | |
281 | return 1; | |
282 | } | |
283 | ||
284 | /* | |
285 | * Main function to be called from the MTD mapping driver/device to | |
286 | * obtain the partitioning information. At this point the command line | |
287 | * arguments will actually be parsed and turned to struct mtd_partition | |
288 | * information. It returns partitions for the requested mtd device, or | |
289 | * the first one in the chain if a NULL mtd_id is passed in. | |
290 | */ | |
291 | static int parse_cmdline_partitions(struct mtd_info *master, | |
292 | struct mtd_partition **pparts, | |
293 | unsigned long origin) | |
294 | { | |
295 | unsigned long offset; | |
296 | int i; | |
297 | struct cmdline_mtd_partition *part; | |
298 | char *mtd_id = master->name; | |
299 | ||
300 | if(!cmdline) | |
301 | return -EINVAL; | |
302 | ||
303 | /* parse command line */ | |
304 | if (!cmdline_parsed) | |
305 | mtdpart_setup_real(cmdline); | |
306 | ||
307 | for(part = partitions; part; part = part->next) | |
308 | { | |
309 | if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id))) | |
310 | { | |
311 | for(i = 0, offset = 0; i < part->num_parts; i++) | |
312 | { | |
313 | if (!part->parts[i].offset) | |
314 | part->parts[i].offset = offset; | |
315 | else | |
316 | offset = part->parts[i].offset; | |
317 | if (part->parts[i].size == SIZE_REMAINING) | |
318 | part->parts[i].size = master->size - offset; | |
319 | if (offset + part->parts[i].size > master->size) | |
320 | { | |
321 | printk(KERN_WARNING ERRP | |
322 | "%s: partitioning exceeds flash size, truncating\n", | |
323 | part->mtd_id); | |
324 | part->parts[i].size = master->size - offset; | |
325 | part->num_parts = i; | |
326 | } | |
327 | offset += part->parts[i].size; | |
328 | } | |
329 | *pparts = part->parts; | |
330 | return part->num_parts; | |
331 | } | |
332 | } | |
333 | return -EINVAL; | |
334 | } | |
335 | ||
336 | ||
337 | /* | |
338 | * This is the handler for our kernel parameter, called from | |
339 | * main.c::checksetup(). Note that we can not yet kmalloc() anything, | |
340 | * so we only save the commandline for later processing. | |
341 | * | |
342 | * This function needs to be visible for bootloaders. | |
343 | */ | |
344 | int mtdpart_setup(char *s) | |
345 | { | |
346 | cmdline = s; | |
347 | return 1; | |
348 | } | |
349 | ||
350 | __setup("mtdparts=", mtdpart_setup); | |
351 | ||
352 | static struct mtd_part_parser cmdline_parser = { | |
353 | .owner = THIS_MODULE, | |
354 | .parse_fn = parse_cmdline_partitions, | |
355 | .name = "cmdlinepart", | |
356 | }; | |
357 | ||
358 | static int __init cmdline_parser_init(void) | |
359 | { | |
360 | return register_mtd_parser(&cmdline_parser); | |
361 | } | |
362 | ||
363 | module_init(cmdline_parser_init); | |
364 | ||
365 | MODULE_LICENSE("GPL"); | |
366 | MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>"); | |
367 | MODULE_DESCRIPTION("Command line configuration of MTD partitions"); |