2 * $Id: cmdline.c,v 1.5 2002/11/06 22:40:04 rmk Exp $
4 * Read flash partition table from command line
6 * Copyright 2002 SYSGO Real-Time Solutions GmbH
8 * The format for the command line is as follows:
10 * mtdparts=<mtddef>[;<mtddef]
11 * <mtddef> := <mtd-id>:<partdef>[,<partdef>]
12 * <partdef> := <size>[@offset][<name>][ro]
13 * <mtd-id> := unique id used in mapping driver/device
14 * <size> := standard linux memsize OR "-" to denote all remaining space
15 * <name> := '(' NAME ')'
19 * 1 NOR Flash, with 1 single writable partition:
22 * 1 NOR Flash with 2 partitions, 1 NAND with one
23 * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
26 #include <linux/kernel.h>
27 #include <linux/slab.h>
29 #include <linux/mtd/mtd.h>
30 #include <linux/mtd/partitions.h>
31 #include <linux/bootmem.h>
33 /* error message prefix */
38 #define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
44 /* special size referring to all the remaining space in a partition */
45 #define SIZE_REMAINING 0xffffffff
47 struct cmdline_mtd_partition {
48 struct cmdline_mtd_partition *next;
51 struct mtd_partition *parts;
54 /* mtdpart_setup() parses into here */
55 static struct cmdline_mtd_partition *partitions;
57 /* the command line passed to mtdpart_setupd() */
59 static int cmdline_parsed = 0;
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.
69 static struct mtd_partition * newpart(char *s,
73 unsigned char **extra_mem_ptr,
76 struct mtd_partition *parts;
78 unsigned long offset = 0;
81 unsigned char *extra_mem;
83 unsigned int mask_flags;
85 /* fetch the partition size */
87 { /* assign all remaining space to this partition */
88 size = SIZE_REMAINING;
93 size = memparse(s, &s);
96 printk(KERN_ERR ERRP "couldn't parse number from input string\n");
101 printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
106 /* fetch partition name and flags */
107 mask_flags = 0; /* this is going to be a regular partition */
109 /* check for offset */
113 offset = memparse(s, &s);
116 printk(KERN_ERR ERRP "couldn't parse number from input string\n");
120 /* now look for name */
130 if ((p = strchr(name, delim)) == 0)
132 printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
141 name_len = 13; /* Partition_000 */
144 /* record name length for memory allocation later */
145 extra_mem_size += name_len + 1;
147 /* test for options */
148 if (strncmp(s, "ro", 2) == 0)
150 mask_flags |= MTD_WRITEABLE;
154 /* test if more partitions are following */
157 if (size == SIZE_REMAINING)
159 printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
162 /* more partitions follow, parse them */
163 if ((parts = newpart(s + 1, &s, num_parts,
164 this_part + 1, &extra_mem, extra_mem_size)) == 0)
168 { /* this is the last partition: allocate space for all */
171 *num_parts = this_part + 1;
172 alloc_size = *num_parts * sizeof(struct mtd_partition) +
174 parts = kmalloc(alloc_size, GFP_KERNEL);
177 printk(KERN_ERR ERRP "out of memory\n");
180 memset(parts, 0, alloc_size);
181 extra_mem = (unsigned char *)(parts + *num_parts);
183 /* enter this partition (offset will be calculated later if it is zero at this point) */
184 parts[this_part].size = size;
185 parts[this_part].offset = offset;
186 parts[this_part].mask_flags = mask_flags;
189 strlcpy(extra_mem, name, name_len + 1);
193 sprintf(extra_mem, "Partition_%03d", this_part);
195 parts[this_part].name = extra_mem;
196 extra_mem += name_len + 1;
198 dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n",
200 parts[this_part].name,
201 parts[this_part].offset,
202 parts[this_part].size,
203 parts[this_part].mask_flags));
205 /* return (updated) pointer to extra_mem memory */
207 *extra_mem_ptr = extra_mem;
209 /* return (updated) pointer command line string */
212 /* return partition table */
217 * Parse the command line.
219 static int mtdpart_setup_real(char *s)
225 struct cmdline_mtd_partition *this_mtd;
226 struct mtd_partition *parts;
233 if (!(p = strchr(s, ':')))
235 printk(KERN_ERR ERRP "no mtd-id\n");
238 mtd_id_len = p - mtd_id;
240 dbg(("parsing <%s>\n", p+1));
243 * parse one mtd. have it reserve memory for the
244 * struct cmdline_mtd_partition and the mtd-id string.
246 parts = newpart(p + 1, /* cmdline */
247 &s, /* out: updated cmdline ptr */
248 &num_parts, /* out: number of parts */
249 0, /* first partition */
250 (unsigned char**)&this_mtd, /* out: extra mem */
251 mtd_id_len + 1 + sizeof(*this_mtd));
255 * An error occurred. We're either:
256 * a) out of memory, or
257 * b) in the middle of the partition spec
258 * Either way, this mtd is hosed and we're
259 * unlikely to succeed in parsing any more
265 this_mtd->parts = parts;
266 this_mtd->num_parts = num_parts;
267 this_mtd->mtd_id = (char*)(this_mtd + 1);
268 strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
270 /* link into chain */
271 this_mtd->next = partitions;
272 partitions = this_mtd;
274 dbg(("mtdid=<%s> num_parts=<%d>\n",
275 this_mtd->mtd_id, this_mtd->num_parts));
278 /* EOS - we're done */
282 /* does another spec follow? */
285 printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
294 * Main function to be called from the MTD mapping driver/device to
295 * obtain the partitioning information. At this point the command line
296 * arguments will actually be parsed and turned to struct mtd_partition
299 int parse_cmdline_partitions(struct mtd_info *master,
300 struct mtd_partition **pparts,
303 unsigned long offset;
305 struct cmdline_mtd_partition *part;
310 /* parse command line */
312 mtdpart_setup_real(cmdline);
314 for(part = partitions; part; part = part->next)
316 if (!strcmp(part->mtd_id, mtd_id))
318 for(i = 0, offset = 0; i < part->num_parts; i++)
320 if (!part->parts[i].offset)
321 part->parts[i].offset = offset;
323 offset = part->parts[i].offset;
324 if (part->parts[i].size == SIZE_REMAINING)
325 part->parts[i].size = master->size - offset;
326 if (offset + part->parts[i].size > master->size)
328 printk(KERN_WARNING ERRP
329 "%s: partitioning exceeds flash size, truncating\n",
331 part->parts[i].size = master->size - offset;
334 offset += part->parts[i].size;
336 *pparts = part->parts;
337 return part->num_parts;
345 * This is the handler for our kernel parameter, called from
346 * main.c::checksetup(). Note that we can not yet kmalloc() anything,
347 * so we only save the commandline for later processing.
349 static int __init mtdpart_setup(char *s)
355 __setup("mtdparts=", mtdpart_setup);
357 EXPORT_SYMBOL(parse_cmdline_partitions);
359 MODULE_LICENSE("GPL");
360 MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
361 MODULE_DESCRIPTION("Command line configuration of MTD partitions");