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v6.8
  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
 59struct 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 */
 67static struct cmdline_mtd_partition *partitions;
 68
 69/* the command line passed to mtdpart_setup() */
 70static char *mtdparts;
 71static char *cmdline;
 72static 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 */
 82static struct mtd_partition * newpart(char *s,
 83				      char **retptr,
 84				      int *num_parts,
 85				      int this_part,
 86				      unsigned char **extra_mem_ptr,
 87				      int extra_mem_size)
 88{
 89	struct mtd_partition *parts;
 90	unsigned long long size, offset = OFFSET_CONTINUOUS;
 91	char *name;
 92	int name_len;
 93	unsigned char *extra_mem;
 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(s, &s);
104		if (!size) {
105			pr_err("partition has size 0\n");
106			return ERR_PTR(-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(s, &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(-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(-EINVAL);
167		}
168		/* more partitions follow, parse them */
169		parts = newpart(s + 1, &s, num_parts, this_part + 1,
170				&extra_mem, extra_mem_size);
171		if (IS_ERR(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(alloc_size, GFP_KERNEL);
182		if (!parts)
183			return ERR_PTR(-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(extra_mem, "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 */
220static 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(p + 1,		/* cmdline */
277				&s,		/* out: updated cmdline ptr */
278				&num_parts,	/* out: number of parts */
279				0,		/* first partition */
280				(unsigned char**)&this_mtd, /* out: extra mem */
281				mtd_id_len + 1 + sizeof(*this_mtd) +
282				sizeof(void*)-1 /*alignment*/);
283		if (IS_ERR(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(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 */
333static 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(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(part->parts, 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 */
403static int __init mtdpart_setup(char *s)
404{
405	cmdline = s;
406	return 1;
407}
408
409__setup("mtdparts=", mtdpart_setup);
410
411static struct mtd_part_parser cmdline_parser = {
412	.parse_fn = parse_cmdline_partitions,
413	.name = "cmdlinepart",
414};
415
416static int __init cmdline_parser_init(void)
417{
418	if (mtdparts)
419		mtdpart_setup(mtdparts);
420	register_mtd_parser(&cmdline_parser);
421	return 0;
422}
423
424static void __exit cmdline_parser_exit(void)
425{
426	deregister_mtd_parser(&cmdline_parser);
427}
428
429module_init(cmdline_parser_init);
430module_exit(cmdline_parser_exit);
431
432MODULE_PARM_DESC(mtdparts, "Partitioning specification");
433module_param(mtdparts, charp, 0);
434
435MODULE_LICENSE("GPL");
436MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
437MODULE_DESCRIPTION("Command line configuration of MTD partitions");
v6.13.7
  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/* special size referring to all the remaining space in a partition */
 48#define SIZE_REMAINING ULLONG_MAX
 49#define OFFSET_CONTINUOUS ULLONG_MAX
 50
 51struct cmdline_mtd_partition {
 52	struct cmdline_mtd_partition *next;
 53	char *mtd_id;
 54	int num_parts;
 55	struct mtd_partition *parts;
 56};
 57
 58/* mtdpart_setup() parses into here */
 59static struct cmdline_mtd_partition *partitions;
 60
 61/* the command line passed to mtdpart_setup() */
 62static char *mtdparts;
 63static char *cmdline;
 64static int cmdline_parsed;
 65
 66/*
 67 * Parse one partition definition for an MTD. Since there can be many
 68 * comma separated partition definitions, this function calls itself
 69 * recursively until no more partition definitions are found. Nice side
 70 * effect: the memory to keep the mtd_partition structs and the names
 71 * is allocated upon the last definition being found. At that point the
 72 * syntax has been verified ok.
 73 */
 74static struct mtd_partition * newpart(char *s,
 75				      char **retptr,
 76				      int *num_parts,
 77				      int this_part,
 78				      unsigned char **extra_mem_ptr,
 79				      int extra_mem_size)
 80{
 81	struct mtd_partition *parts;
 82	unsigned long long size, offset = OFFSET_CONTINUOUS;
 83	char *name;
 84	int name_len;
 85	unsigned char *extra_mem;
 86	char delim;
 87	unsigned int mask_flags, add_flags;
 88
 89	/* fetch the partition size */
 90	if (*s == '-') {
 91		/* assign all remaining space to this partition */
 92		size = SIZE_REMAINING;
 93		s++;
 94	} else {
 95		size = memparse(s, &s);
 96		if (!size) {
 97			pr_err("partition has size 0\n");
 98			return ERR_PTR(-EINVAL);
 99		}
100	}
101
102	/* fetch partition name and flags */
103	mask_flags = 0; /* this is going to be a regular partition */
104	add_flags = 0;
105	delim = 0;
106
107	/* check for offset */
108	if (*s == '@') {
109		s++;
110		offset = memparse(s, &s);
111	}
112
113	/* now look for name */
114	if (*s == '(')
115		delim = ')';
116
117	if (delim) {
118		char *p;
119
120		name = ++s;
121		p = strchr(name, delim);
122		if (!p) {
123			pr_err("no closing %c found in partition name\n", delim);
124			return ERR_PTR(-EINVAL);
125		}
126		name_len = p - name;
127		s = p + 1;
128	} else {
129		name = NULL;
130		name_len = 13; /* Partition_000 */
131	}
132
133	/* record name length for memory allocation later */
134	extra_mem_size += name_len + 1;
135
136	/* test for options */
137	if (strncmp(s, "ro", 2) == 0) {
138		mask_flags |= MTD_WRITEABLE;
139		s += 2;
140	}
141
142	/* if lk is found do NOT unlock the MTD partition*/
143	if (strncmp(s, "lk", 2) == 0) {
144		mask_flags |= MTD_POWERUP_LOCK;
145		s += 2;
146	}
147
148	/* if slc is found use emulated SLC mode on this partition*/
149	if (!strncmp(s, "slc", 3)) {
150		add_flags |= MTD_SLC_ON_MLC_EMULATION;
151		s += 3;
152	}
153
154	/* test if more partitions are following */
155	if (*s == ',') {
156		if (size == SIZE_REMAINING) {
157			pr_err("no partitions allowed after a fill-up partition\n");
158			return ERR_PTR(-EINVAL);
159		}
160		/* more partitions follow, parse them */
161		parts = newpart(s + 1, &s, num_parts, this_part + 1,
162				&extra_mem, extra_mem_size);
163		if (IS_ERR(parts))
164			return parts;
165	} else {
166		/* this is the last partition: allocate space for all */
167		int alloc_size;
168
169		*num_parts = this_part + 1;
170		alloc_size = *num_parts * sizeof(struct mtd_partition) +
171			     extra_mem_size;
172
173		parts = kzalloc(alloc_size, GFP_KERNEL);
174		if (!parts)
175			return ERR_PTR(-ENOMEM);
176		extra_mem = (unsigned char *)(parts + *num_parts);
177	}
178
179	/*
180	 * enter this partition (offset will be calculated later if it is
181	 * OFFSET_CONTINUOUS at this point)
182	 */
183	parts[this_part].size = size;
184	parts[this_part].offset = offset;
185	parts[this_part].mask_flags = mask_flags;
186	parts[this_part].add_flags = add_flags;
187	if (name)
188		strscpy(extra_mem, name, name_len + 1);
189	else
190		sprintf(extra_mem, "Partition_%03d", this_part);
191	parts[this_part].name = extra_mem;
192	extra_mem += name_len + 1;
193
194	pr_debug("partition %d: name <%s>, offset %llx, size %llx, mask flags %x\n",
195	     this_part, parts[this_part].name, parts[this_part].offset,
196	     parts[this_part].size, parts[this_part].mask_flags);
197
198	/* return (updated) pointer to extra_mem memory */
199	if (extra_mem_ptr)
200		*extra_mem_ptr = extra_mem;
201
202	/* return (updated) pointer command line string */
203	*retptr = s;
204
205	/* return partition table */
206	return parts;
207}
208
209/*
210 * Parse the command line.
211 */
212static int mtdpart_setup_real(char *s)
213{
214	cmdline_parsed = 1;
215
216	for( ; s != NULL; )
217	{
218		struct cmdline_mtd_partition *this_mtd;
219		struct mtd_partition *parts;
220		int mtd_id_len, num_parts;
221		char *p, *mtd_id, *semicol, *open_parenth;
222
223		/*
224		 * Replace the first ';' by a NULL char so strrchr can work
225		 * properly.
226		 */
227		semicol = strchr(s, ';');
228		if (semicol)
229			*semicol = '\0';
230
231		/*
232		 * make sure that part-names with ":" will not be handled as
233		 * part of the mtd-id with an ":"
234		 */
235		open_parenth = strchr(s, '(');
236		if (open_parenth)
237			*open_parenth = '\0';
238
239		mtd_id = s;
240
241		/*
242		 * fetch <mtd-id>. We use strrchr to ignore all ':' that could
243		 * be present in the MTD name, only the last one is interpreted
244		 * as an <mtd-id>/<part-definition> separator.
245		 */
246		p = strrchr(s, ':');
247
248		/* Restore the '(' now. */
249		if (open_parenth)
250			*open_parenth = '(';
251
252		/* Restore the ';' now. */
253		if (semicol)
254			*semicol = ';';
255
256		if (!p) {
257			pr_err("no mtd-id\n");
258			return -EINVAL;
259		}
260		mtd_id_len = p - mtd_id;
261
262		pr_debug("parsing <%s>\n", p+1);
263
264		/*
265		 * parse one mtd. have it reserve memory for the
266		 * struct cmdline_mtd_partition and the mtd-id string.
267		 */
268		parts = newpart(p + 1,		/* cmdline */
269				&s,		/* out: updated cmdline ptr */
270				&num_parts,	/* out: number of parts */
271				0,		/* first partition */
272				(unsigned char**)&this_mtd, /* out: extra mem */
273				mtd_id_len + 1 + sizeof(*this_mtd) +
274				sizeof(void*)-1 /*alignment*/);
275		if (IS_ERR(parts)) {
276			/*
277			 * An error occurred. We're either:
278			 * a) out of memory, or
279			 * b) in the middle of the partition spec
280			 * Either way, this mtd is hosed and we're
281			 * unlikely to succeed in parsing any more
282			 */
283			 return PTR_ERR(parts);
284		 }
285
286		/* align this_mtd */
287		this_mtd = (struct cmdline_mtd_partition *)
288				ALIGN((unsigned long)this_mtd, sizeof(void *));
289		/* enter results */
290		this_mtd->parts = parts;
291		this_mtd->num_parts = num_parts;
292		this_mtd->mtd_id = (char*)(this_mtd + 1);
293		strscpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
294
295		/* link into chain */
296		this_mtd->next = partitions;
297		partitions = this_mtd;
298
299		pr_debug("mtdid=<%s> num_parts=<%d>\n",
300		     this_mtd->mtd_id, this_mtd->num_parts);
301
302
303		/* EOS - we're done */
304		if (*s == 0)
305			break;
306
307		/* does another spec follow? */
308		if (*s != ';') {
309			pr_err("bad character after partition (%c)\n", *s);
310			return -EINVAL;
311		}
312		s++;
313	}
314
315	return 0;
316}
317
318/*
319 * Main function to be called from the MTD mapping driver/device to
320 * obtain the partitioning information. At this point the command line
321 * arguments will actually be parsed and turned to struct mtd_partition
322 * information. It returns partitions for the requested mtd device, or
323 * the first one in the chain if a NULL mtd_id is passed in.
324 */
325static int parse_cmdline_partitions(struct mtd_info *master,
326				    const struct mtd_partition **pparts,
327				    struct mtd_part_parser_data *data)
328{
329	unsigned long long offset;
330	int i, err;
331	struct cmdline_mtd_partition *part;
332	const char *mtd_id = master->name;
333
334	/* parse command line */
335	if (!cmdline_parsed) {
336		err = mtdpart_setup_real(cmdline);
337		if (err)
338			return err;
339	}
340
341	/*
342	 * Search for the partition definition matching master->name.
343	 * If master->name is not set, stop at first partition definition.
344	 */
345	for (part = partitions; part; part = part->next) {
346		if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
347			break;
348	}
349
350	if (!part)
351		return 0;
352
353	for (i = 0, offset = 0; i < part->num_parts; i++) {
354		if (part->parts[i].offset == OFFSET_CONTINUOUS)
355			part->parts[i].offset = offset;
356		else
357			offset = part->parts[i].offset;
358
359		if (part->parts[i].size == SIZE_REMAINING)
360			part->parts[i].size = master->size - offset;
361
362		if (offset + part->parts[i].size > master->size) {
363			pr_warn("%s: partitioning exceeds flash size, truncating\n",
364				part->mtd_id);
365			part->parts[i].size = master->size - offset;
366		}
367		offset += part->parts[i].size;
368
369		if (part->parts[i].size == 0) {
370			pr_warn("%s: skipping zero sized partition\n",
371				part->mtd_id);
372			part->num_parts--;
373			memmove(&part->parts[i], &part->parts[i + 1],
374				sizeof(*part->parts) * (part->num_parts - i));
375			i--;
376		}
377	}
378
379	*pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts,
380			  GFP_KERNEL);
381	if (!*pparts)
382		return -ENOMEM;
383
384	return part->num_parts;
385}
386
387
388/*
389 * This is the handler for our kernel parameter, called from
390 * main.c::checksetup(). Note that we can not yet kmalloc() anything,
391 * so we only save the commandline for later processing.
392 *
393 * This function needs to be visible for bootloaders.
394 */
395static int __init mtdpart_setup(char *s)
396{
397	cmdline = s;
398	return 1;
399}
400
401__setup("mtdparts=", mtdpart_setup);
402
403static struct mtd_part_parser cmdline_parser = {
404	.parse_fn = parse_cmdline_partitions,
405	.name = "cmdlinepart",
406};
407
408static int __init cmdline_parser_init(void)
409{
410	if (mtdparts)
411		mtdpart_setup(mtdparts);
412	register_mtd_parser(&cmdline_parser);
413	return 0;
414}
415
416static void __exit cmdline_parser_exit(void)
417{
418	deregister_mtd_parser(&cmdline_parser);
419}
420
421module_init(cmdline_parser_init);
422module_exit(cmdline_parser_exit);
423
424MODULE_PARM_DESC(mtdparts, "Partitioning specification");
425module_param(mtdparts, charp, 0);
426
427MODULE_LICENSE("GPL");
428MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
429MODULE_DESCRIPTION("Command line configuration of MTD partitions");