1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Read flash partition table from command line |
4 | * |
5 | * Copyright © 2002 SYSGO Real-Time Solutions GmbH |
6 | * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org> |
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][lk][slc] |
13 | * <mtd-id> := unique name used in mapping driver/device (mtd->name) |
14 | * <size> := standard linux memsize OR "-" to denote all remaining space |
15 | * size is automatically truncated at end of device |
16 | * if specified or truncated size is 0 the part is skipped |
17 | * <offset> := standard linux memsize |
18 | * if omitted the part will immediately follow the previous part |
19 | * or 0 if the first part |
20 | * <name> := '(' NAME ')' |
21 | * NAME will appear in /proc/mtd |
22 | * |
23 | * <size> and <offset> can be specified such that the parts are out of order |
24 | * in physical memory and may even overlap. |
25 | * |
26 | * The parts are assigned MTD numbers in the order they are specified in the |
27 | * command line regardless of their order in physical memory. |
28 | * |
29 | * Examples: |
30 | * |
31 | * 1 NOR Flash, with 1 single writable partition: |
32 | * edb7312-nor:- |
33 | * |
34 | * 1 NOR Flash with 2 partitions, 1 NAND with one |
35 | * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home) |
36 | */ |
37 | |
38 | #define pr_fmt(fmt) "mtd: " fmt |
39 | |
40 | #include <linux/kernel.h> |
41 | #include <linux/slab.h> |
42 | #include <linux/mtd/mtd.h> |
43 | #include <linux/mtd/partitions.h> |
44 | #include <linux/module.h> |
45 | #include <linux/err.h> |
46 | |
47 | /* debug macro */ |
48 | #if 0 |
49 | #define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0) |
50 | #else |
51 | #define dbg(x) |
52 | #endif |
53 | |
54 | |
55 | /* special size referring to all the remaining space in a partition */ |
56 | #define SIZE_REMAINING ULLONG_MAX |
57 | #define OFFSET_CONTINUOUS ULLONG_MAX |
58 | |
59 | struct cmdline_mtd_partition { |
60 | struct cmdline_mtd_partition *next; |
61 | char *mtd_id; |
62 | int num_parts; |
63 | struct mtd_partition *parts; |
64 | }; |
65 | |
66 | /* mtdpart_setup() parses into here */ |
67 | static struct cmdline_mtd_partition *partitions; |
68 | |
69 | /* the command line passed to mtdpart_setup() */ |
70 | static char *mtdparts; |
71 | static char *cmdline; |
72 | static int cmdline_parsed; |
73 | |
74 | /* |
75 | * Parse one partition definition for an MTD. Since there can be many |
76 | * comma separated partition definitions, this function calls itself |
77 | * recursively until no more partition definitions are found. Nice side |
78 | * effect: the memory to keep the mtd_partition structs and the names |
79 | * is allocated upon the last definition being found. At that point the |
80 | * syntax has been verified ok. |
81 | */ |
82 | static struct mtd_partition * newpart(char *s, |
83 | char **retptr, |
84 | int *num_parts, |
85 | int this_part, |
86 | unsigned char **, |
87 | int ) |
88 | { |
89 | struct mtd_partition *parts; |
90 | unsigned long long size, offset = OFFSET_CONTINUOUS; |
91 | char *name; |
92 | int name_len; |
93 | unsigned char *; |
94 | char delim; |
95 | unsigned int mask_flags, add_flags; |
96 | |
97 | /* fetch the partition size */ |
98 | if (*s == '-') { |
99 | /* assign all remaining space to this partition */ |
100 | size = SIZE_REMAINING; |
101 | s++; |
102 | } else { |
103 | size = memparse(ptr: s, retptr: &s); |
104 | if (!size) { |
105 | pr_err("partition has size 0\n" ); |
106 | return ERR_PTR(error: -EINVAL); |
107 | } |
108 | } |
109 | |
110 | /* fetch partition name and flags */ |
111 | mask_flags = 0; /* this is going to be a regular partition */ |
112 | add_flags = 0; |
113 | delim = 0; |
114 | |
115 | /* check for offset */ |
116 | if (*s == '@') { |
117 | s++; |
118 | offset = memparse(ptr: s, retptr: &s); |
119 | } |
120 | |
121 | /* now look for name */ |
122 | if (*s == '(') |
123 | delim = ')'; |
124 | |
125 | if (delim) { |
126 | char *p; |
127 | |
128 | name = ++s; |
129 | p = strchr(name, delim); |
130 | if (!p) { |
131 | pr_err("no closing %c found in partition name\n" , delim); |
132 | return ERR_PTR(error: -EINVAL); |
133 | } |
134 | name_len = p - name; |
135 | s = p + 1; |
136 | } else { |
137 | name = NULL; |
138 | name_len = 13; /* Partition_000 */ |
139 | } |
140 | |
141 | /* record name length for memory allocation later */ |
142 | extra_mem_size += name_len + 1; |
143 | |
144 | /* test for options */ |
145 | if (strncmp(s, "ro" , 2) == 0) { |
146 | mask_flags |= MTD_WRITEABLE; |
147 | s += 2; |
148 | } |
149 | |
150 | /* if lk is found do NOT unlock the MTD partition*/ |
151 | if (strncmp(s, "lk" , 2) == 0) { |
152 | mask_flags |= MTD_POWERUP_LOCK; |
153 | s += 2; |
154 | } |
155 | |
156 | /* if slc is found use emulated SLC mode on this partition*/ |
157 | if (!strncmp(s, "slc" , 3)) { |
158 | add_flags |= MTD_SLC_ON_MLC_EMULATION; |
159 | s += 3; |
160 | } |
161 | |
162 | /* test if more partitions are following */ |
163 | if (*s == ',') { |
164 | if (size == SIZE_REMAINING) { |
165 | pr_err("no partitions allowed after a fill-up partition\n" ); |
166 | return ERR_PTR(error: -EINVAL); |
167 | } |
168 | /* more partitions follow, parse them */ |
169 | parts = newpart(s: s + 1, retptr: &s, num_parts, this_part: this_part + 1, |
170 | extra_mem_ptr: &extra_mem, extra_mem_size); |
171 | if (IS_ERR(ptr: parts)) |
172 | return parts; |
173 | } else { |
174 | /* this is the last partition: allocate space for all */ |
175 | int alloc_size; |
176 | |
177 | *num_parts = this_part + 1; |
178 | alloc_size = *num_parts * sizeof(struct mtd_partition) + |
179 | extra_mem_size; |
180 | |
181 | parts = kzalloc(size: alloc_size, GFP_KERNEL); |
182 | if (!parts) |
183 | return ERR_PTR(error: -ENOMEM); |
184 | extra_mem = (unsigned char *)(parts + *num_parts); |
185 | } |
186 | |
187 | /* |
188 | * enter this partition (offset will be calculated later if it is |
189 | * OFFSET_CONTINUOUS at this point) |
190 | */ |
191 | parts[this_part].size = size; |
192 | parts[this_part].offset = offset; |
193 | parts[this_part].mask_flags = mask_flags; |
194 | parts[this_part].add_flags = add_flags; |
195 | if (name) |
196 | strscpy(extra_mem, name, name_len + 1); |
197 | else |
198 | sprintf(buf: extra_mem, fmt: "Partition_%03d" , this_part); |
199 | parts[this_part].name = extra_mem; |
200 | extra_mem += name_len + 1; |
201 | |
202 | dbg(("partition %d: name <%s>, offset %llx, size %llx, mask flags %x\n" , |
203 | this_part, parts[this_part].name, parts[this_part].offset, |
204 | parts[this_part].size, parts[this_part].mask_flags)); |
205 | |
206 | /* return (updated) pointer to extra_mem memory */ |
207 | if (extra_mem_ptr) |
208 | *extra_mem_ptr = extra_mem; |
209 | |
210 | /* return (updated) pointer command line string */ |
211 | *retptr = s; |
212 | |
213 | /* return partition table */ |
214 | return parts; |
215 | } |
216 | |
217 | /* |
218 | * Parse the command line. |
219 | */ |
220 | static int mtdpart_setup_real(char *s) |
221 | { |
222 | cmdline_parsed = 1; |
223 | |
224 | for( ; s != NULL; ) |
225 | { |
226 | struct cmdline_mtd_partition *this_mtd; |
227 | struct mtd_partition *parts; |
228 | int mtd_id_len, num_parts; |
229 | char *p, *mtd_id, *semicol, *open_parenth; |
230 | |
231 | /* |
232 | * Replace the first ';' by a NULL char so strrchr can work |
233 | * properly. |
234 | */ |
235 | semicol = strchr(s, ';'); |
236 | if (semicol) |
237 | *semicol = '\0'; |
238 | |
239 | /* |
240 | * make sure that part-names with ":" will not be handled as |
241 | * part of the mtd-id with an ":" |
242 | */ |
243 | open_parenth = strchr(s, '('); |
244 | if (open_parenth) |
245 | *open_parenth = '\0'; |
246 | |
247 | mtd_id = s; |
248 | |
249 | /* |
250 | * fetch <mtd-id>. We use strrchr to ignore all ':' that could |
251 | * be present in the MTD name, only the last one is interpreted |
252 | * as an <mtd-id>/<part-definition> separator. |
253 | */ |
254 | p = strrchr(s, ':'); |
255 | |
256 | /* Restore the '(' now. */ |
257 | if (open_parenth) |
258 | *open_parenth = '('; |
259 | |
260 | /* Restore the ';' now. */ |
261 | if (semicol) |
262 | *semicol = ';'; |
263 | |
264 | if (!p) { |
265 | pr_err("no mtd-id\n" ); |
266 | return -EINVAL; |
267 | } |
268 | mtd_id_len = p - mtd_id; |
269 | |
270 | dbg(("parsing <%s>\n" , p+1)); |
271 | |
272 | /* |
273 | * parse one mtd. have it reserve memory for the |
274 | * struct cmdline_mtd_partition and the mtd-id string. |
275 | */ |
276 | parts = newpart(s: p + 1, /* cmdline */ |
277 | retptr: &s, /* out: updated cmdline ptr */ |
278 | num_parts: &num_parts, /* out: number of parts */ |
279 | this_part: 0, /* first partition */ |
280 | extra_mem_ptr: (unsigned char**)&this_mtd, /* out: extra mem */ |
281 | extra_mem_size: mtd_id_len + 1 + sizeof(*this_mtd) + |
282 | sizeof(void*)-1 /*alignment*/); |
283 | if (IS_ERR(ptr: parts)) { |
284 | /* |
285 | * An error occurred. We're either: |
286 | * a) out of memory, or |
287 | * b) in the middle of the partition spec |
288 | * Either way, this mtd is hosed and we're |
289 | * unlikely to succeed in parsing any more |
290 | */ |
291 | return PTR_ERR(ptr: parts); |
292 | } |
293 | |
294 | /* align this_mtd */ |
295 | this_mtd = (struct cmdline_mtd_partition *) |
296 | ALIGN((unsigned long)this_mtd, sizeof(void *)); |
297 | /* enter results */ |
298 | this_mtd->parts = parts; |
299 | this_mtd->num_parts = num_parts; |
300 | this_mtd->mtd_id = (char*)(this_mtd + 1); |
301 | strscpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1); |
302 | |
303 | /* link into chain */ |
304 | this_mtd->next = partitions; |
305 | partitions = this_mtd; |
306 | |
307 | dbg(("mtdid=<%s> num_parts=<%d>\n" , |
308 | this_mtd->mtd_id, this_mtd->num_parts)); |
309 | |
310 | |
311 | /* EOS - we're done */ |
312 | if (*s == 0) |
313 | break; |
314 | |
315 | /* does another spec follow? */ |
316 | if (*s != ';') { |
317 | pr_err("bad character after partition (%c)\n" , *s); |
318 | return -EINVAL; |
319 | } |
320 | s++; |
321 | } |
322 | |
323 | return 0; |
324 | } |
325 | |
326 | /* |
327 | * Main function to be called from the MTD mapping driver/device to |
328 | * obtain the partitioning information. At this point the command line |
329 | * arguments will actually be parsed and turned to struct mtd_partition |
330 | * information. It returns partitions for the requested mtd device, or |
331 | * the first one in the chain if a NULL mtd_id is passed in. |
332 | */ |
333 | static int parse_cmdline_partitions(struct mtd_info *master, |
334 | const struct mtd_partition **pparts, |
335 | struct mtd_part_parser_data *data) |
336 | { |
337 | unsigned long long offset; |
338 | int i, err; |
339 | struct cmdline_mtd_partition *part; |
340 | const char *mtd_id = master->name; |
341 | |
342 | /* parse command line */ |
343 | if (!cmdline_parsed) { |
344 | err = mtdpart_setup_real(s: cmdline); |
345 | if (err) |
346 | return err; |
347 | } |
348 | |
349 | /* |
350 | * Search for the partition definition matching master->name. |
351 | * If master->name is not set, stop at first partition definition. |
352 | */ |
353 | for (part = partitions; part; part = part->next) { |
354 | if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id))) |
355 | break; |
356 | } |
357 | |
358 | if (!part) |
359 | return 0; |
360 | |
361 | for (i = 0, offset = 0; i < part->num_parts; i++) { |
362 | if (part->parts[i].offset == OFFSET_CONTINUOUS) |
363 | part->parts[i].offset = offset; |
364 | else |
365 | offset = part->parts[i].offset; |
366 | |
367 | if (part->parts[i].size == SIZE_REMAINING) |
368 | part->parts[i].size = master->size - offset; |
369 | |
370 | if (offset + part->parts[i].size > master->size) { |
371 | pr_warn("%s: partitioning exceeds flash size, truncating\n" , |
372 | part->mtd_id); |
373 | part->parts[i].size = master->size - offset; |
374 | } |
375 | offset += part->parts[i].size; |
376 | |
377 | if (part->parts[i].size == 0) { |
378 | pr_warn("%s: skipping zero sized partition\n" , |
379 | part->mtd_id); |
380 | part->num_parts--; |
381 | memmove(&part->parts[i], &part->parts[i + 1], |
382 | sizeof(*part->parts) * (part->num_parts - i)); |
383 | i--; |
384 | } |
385 | } |
386 | |
387 | *pparts = kmemdup(p: part->parts, size: sizeof(*part->parts) * part->num_parts, |
388 | GFP_KERNEL); |
389 | if (!*pparts) |
390 | return -ENOMEM; |
391 | |
392 | return part->num_parts; |
393 | } |
394 | |
395 | |
396 | /* |
397 | * This is the handler for our kernel parameter, called from |
398 | * main.c::checksetup(). Note that we can not yet kmalloc() anything, |
399 | * so we only save the commandline for later processing. |
400 | * |
401 | * This function needs to be visible for bootloaders. |
402 | */ |
403 | static int __init mtdpart_setup(char *s) |
404 | { |
405 | cmdline = s; |
406 | return 1; |
407 | } |
408 | |
409 | __setup("mtdparts=" , mtdpart_setup); |
410 | |
411 | static struct mtd_part_parser cmdline_parser = { |
412 | .parse_fn = parse_cmdline_partitions, |
413 | .name = "cmdlinepart" , |
414 | }; |
415 | |
416 | static int __init cmdline_parser_init(void) |
417 | { |
418 | if (mtdparts) |
419 | mtdpart_setup(s: mtdparts); |
420 | register_mtd_parser(&cmdline_parser); |
421 | return 0; |
422 | } |
423 | |
424 | static void __exit cmdline_parser_exit(void) |
425 | { |
426 | deregister_mtd_parser(parser: &cmdline_parser); |
427 | } |
428 | |
429 | module_init(cmdline_parser_init); |
430 | module_exit(cmdline_parser_exit); |
431 | |
432 | MODULE_PARM_DESC(mtdparts, "Partitioning specification" ); |
433 | module_param(mtdparts, charp, 0); |
434 | |
435 | MODULE_LICENSE("GPL" ); |
436 | MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>" ); |
437 | MODULE_DESCRIPTION("Command line configuration of MTD partitions" ); |
438 | |