2 * $Id: cmdlinepart.c,v 1.6 2002/11/16 01:37:39 dneuer 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 <asm/setup.h>
32 #include <linux/bootmem.h>
34 /* error message prefix */
39 #define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
45 /* special size referring to all the remaining space in a partition */
46 #define SIZE_REMAINING 0xffffffff
48 struct cmdline_mtd_partition {
49 struct cmdline_mtd_partition *next;
52 struct mtd_partition *parts;
55 /* mtdpart_setup() parses into here */
56 static struct cmdline_mtd_partition *partitions;
58 /* the command line passed to mtdpart_setupd() */
60 static int cmdline_parsed = 0;
63 * Parse one partition definition for an MTD. Since there can be many
64 * comma separated partition definitions, this function calls itself
65 * recursively until no more partition definitions are found. Nice side
66 * effect: the memory to keep the mtd_partition structs and the names
67 * is allocated upon the last definition being found. At that point the
68 * syntax has been verified ok.
70 static struct mtd_partition * newpart(char *s,
74 unsigned char **extra_mem_ptr,
77 struct mtd_partition *parts;
79 unsigned long offset = 0;
82 unsigned char *extra_mem;
84 unsigned int mask_flags;
86 /* fetch the partition size */
88 { /* assign all remaining space to this partition */
89 size = SIZE_REMAINING;
94 size = memparse(s, &s);
97 printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
102 /* fetch partition name and flags */
103 mask_flags = 0; /* this is going to be a regular partition */
105 /* check for offset */
109 offset = memparse(s, &s);
111 /* now look for name */
122 if ((p = strchr(name, delim)) == 0)
124 printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
133 name_len = 13; /* Partition_000 */
136 /* record name length for memory allocation later */
137 extra_mem_size += name_len + 1;
139 /* test for options */
140 if (strncmp(s, "ro", 2) == 0)
142 mask_flags |= MTD_WRITEABLE;
146 /* test if more partitions are following */
149 if (size == SIZE_REMAINING)
151 printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
154 /* more partitions follow, parse them */
155 if ((parts = newpart(s + 1, &s, num_parts,
156 this_part + 1, &extra_mem, extra_mem_size)) == 0)
160 { /* this is the last partition: allocate space for all */
163 *num_parts = this_part + 1;
164 alloc_size = *num_parts * sizeof(struct mtd_partition) +
166 parts = kmalloc(alloc_size, GFP_KERNEL);
169 printk(KERN_ERR ERRP "out of memory\n");
172 memset(parts, 0, alloc_size);
173 extra_mem = (unsigned char *)(parts + *num_parts);
175 /* enter this partition (offset will be calculated later if it is zero at this point) */
176 parts[this_part].size = size;
177 parts[this_part].offset = offset;
178 parts[this_part].mask_flags = mask_flags;
181 strncpy(extra_mem, name, name_len);
182 extra_mem[name_len] = 0;
186 sprintf(extra_mem, "Partition_%03d", this_part);
188 parts[this_part].name = extra_mem;
189 extra_mem += name_len + 1;
191 dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n",
193 parts[this_part].name,
194 parts[this_part].offset,
195 parts[this_part].size,
196 parts[this_part].mask_flags));
198 /* return (updated) pointer to extra_mem memory */
200 *extra_mem_ptr = extra_mem;
202 /* return (updated) pointer command line string */
205 /* return partition table */
210 * Parse the command line.
212 static int mtdpart_setup_real(char *s)
218 struct cmdline_mtd_partition *this_mtd;
219 struct mtd_partition *parts;
226 if (!(p = strchr(s, ':')))
228 printk(KERN_ERR ERRP "no mtd-id\n");
231 mtd_id_len = p - mtd_id;
233 dbg(("parsing <%s>\n", p+1));
236 * parse one mtd. have it reserve memory for the
237 * struct cmdline_mtd_partition and the mtd-id string.
239 parts = newpart(p + 1, /* cmdline */
240 &s, /* out: updated cmdline ptr */
241 &num_parts, /* out: number of parts */
242 0, /* first partition */
243 (unsigned char**)&this_mtd, /* out: extra mem */
244 mtd_id_len + 1 + sizeof(*this_mtd));
248 * An error occurred. We're either:
249 * a) out of memory, or
250 * b) in the middle of the partition spec
251 * Either way, this mtd is hosed and we're
252 * unlikely to succeed in parsing any more
258 this_mtd->parts = parts;
259 this_mtd->num_parts = num_parts;
260 this_mtd->mtd_id = (char*)(this_mtd + 1);
261 strncpy(this_mtd->mtd_id, mtd_id, mtd_id_len);
262 this_mtd->mtd_id[mtd_id_len] = 0;
264 /* link into chain */
265 this_mtd->next = partitions;
266 partitions = this_mtd;
268 dbg(("mtdid=<%s> num_parts=<%d>\n",
269 this_mtd->mtd_id, this_mtd->num_parts));
272 /* EOS - we're done */
276 /* does another spec follow? */
279 printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
288 * Main function to be called from the MTD mapping driver/device to
289 * obtain the partitioning information. At this point the command line
290 * arguments will actually be parsed and turned to struct mtd_partition
291 * information. It returns partitions for the requested mtd device, or
292 * the first one in the chain if a NULL mtd_id is passed in.
294 int parse_cmdline_partitions(struct mtd_info *master,
295 struct mtd_partition **pparts,
298 unsigned long offset;
300 struct cmdline_mtd_partition *part;
305 /* parse command line */
307 mtdpart_setup_real(cmdline);
309 for(part = partitions; part; part = part->next)
311 if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
313 for(i = 0, offset = 0; i < part->num_parts; i++)
315 if (!part->parts[i].offset)
316 part->parts[i].offset = offset;
318 offset = part->parts[i].offset;
319 if (part->parts[i].size == SIZE_REMAINING)
320 part->parts[i].size = master->size - offset;
321 if (offset + part->parts[i].size > master->size)
323 printk(KERN_WARNING ERRP
324 "%s: partitioning exceeds flash size, truncating\n",
326 part->parts[i].size = master->size - offset;
329 offset += part->parts[i].size;
331 *pparts = part->parts;
332 return part->num_parts;
340 * This is the handler for our kernel parameter, called from
341 * main.c::checksetup(). Note that we can not yet kmalloc() anything,
342 * so we only save the commandline for later processing.
344 static int __init mtdpart_setup(char *s)
350 __setup("mtdparts=", mtdpart_setup);
352 EXPORT_SYMBOL(parse_cmdline_partitions);
354 MODULE_LICENSE("GPL");
355 MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
356 MODULE_DESCRIPTION("Command line configuration of MTD partitions");