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path: root/drivers/mtd/cmdlinepart.c
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Diffstat (limited to 'drivers/mtd/cmdlinepart.c')
-rw-r--r--drivers/mtd/cmdlinepart.c367
1 files changed, 367 insertions, 0 deletions
diff --git a/drivers/mtd/cmdlinepart.c b/drivers/mtd/cmdlinepart.c
new file mode 100644
index 00000000000..60ab4b89a2f
--- /dev/null
+++ b/drivers/mtd/cmdlinepart.c
@@ -0,0 +1,367 @@
+/*
+ * $Id: cmdlinepart.c,v 1.17 2004/11/26 11:18:47 lavinen Exp $
+ *
+ * Read flash partition table from command line
+ *
+ * Copyright 2002 SYSGO Real-Time Solutions GmbH
+ *
+ * The format for the command line is as follows:
+ *
+ * mtdparts=<mtddef>[;<mtddef]
+ * <mtddef> := <mtd-id>:<partdef>[,<partdef>]
+ * <partdef> := <size>[@offset][<name>][ro]
+ * <mtd-id> := unique name used in mapping driver/device (mtd->name)
+ * <size> := standard linux memsize OR "-" to denote all remaining space
+ * <name> := '(' NAME ')'
+ *
+ * Examples:
+ *
+ * 1 NOR Flash, with 1 single writable partition:
+ * edb7312-nor:-
+ *
+ * 1 NOR Flash with 2 partitions, 1 NAND with one
+ * edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/bootmem.h>
+
+/* error message prefix */
+#define ERRP "mtd: "
+
+/* debug macro */
+#if 0
+#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
+#else
+#define dbg(x)
+#endif
+
+
+/* special size referring to all the remaining space in a partition */
+#define SIZE_REMAINING 0xffffffff
+
+struct cmdline_mtd_partition {
+ struct cmdline_mtd_partition *next;
+ char *mtd_id;
+ int num_parts;
+ struct mtd_partition *parts;
+};
+
+/* mtdpart_setup() parses into here */
+static struct cmdline_mtd_partition *partitions;
+
+/* the command line passed to mtdpart_setupd() */
+static char *cmdline;
+static int cmdline_parsed = 0;
+
+/*
+ * Parse one partition definition for an MTD. Since there can be many
+ * comma separated partition definitions, this function calls itself
+ * recursively until no more partition definitions are found. Nice side
+ * effect: the memory to keep the mtd_partition structs and the names
+ * is allocated upon the last definition being found. At that point the
+ * syntax has been verified ok.
+ */
+static struct mtd_partition * newpart(char *s,
+ char **retptr,
+ int *num_parts,
+ int this_part,
+ unsigned char **extra_mem_ptr,
+ int extra_mem_size)
+{
+ struct mtd_partition *parts;
+ unsigned long size;
+ unsigned long offset = 0;
+ char *name;
+ int name_len;
+ unsigned char *extra_mem;
+ char delim;
+ unsigned int mask_flags;
+
+ /* fetch the partition size */
+ if (*s == '-')
+ { /* assign all remaining space to this partition */
+ size = SIZE_REMAINING;
+ s++;
+ }
+ else
+ {
+ size = memparse(s, &s);
+ if (size < PAGE_SIZE)
+ {
+ printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
+ return NULL;
+ }
+ }
+
+ /* fetch partition name and flags */
+ mask_flags = 0; /* this is going to be a regular partition */
+ delim = 0;
+ /* check for offset */
+ if (*s == '@')
+ {
+ s++;
+ offset = memparse(s, &s);
+ }
+ /* now look for name */
+ if (*s == '(')
+ {
+ delim = ')';
+ }
+
+ if (delim)
+ {
+ char *p;
+
+ name = ++s;
+ if ((p = strchr(name, delim)) == 0)
+ {
+ printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
+ return NULL;
+ }
+ name_len = p - name;
+ s = p + 1;
+ }
+ else
+ {
+ name = NULL;
+ name_len = 13; /* Partition_000 */
+ }
+
+ /* record name length for memory allocation later */
+ extra_mem_size += name_len + 1;
+
+ /* test for options */
+ if (strncmp(s, "ro", 2) == 0)
+ {
+ mask_flags |= MTD_WRITEABLE;
+ s += 2;
+ }
+
+ /* test if more partitions are following */
+ if (*s == ',')
+ {
+ if (size == SIZE_REMAINING)
+ {
+ printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
+ return NULL;
+ }
+ /* more partitions follow, parse them */
+ if ((parts = newpart(s + 1, &s, num_parts,
+ this_part + 1, &extra_mem, extra_mem_size)) == 0)
+ return NULL;
+ }
+ else
+ { /* this is the last partition: allocate space for all */
+ int alloc_size;
+
+ *num_parts = this_part + 1;
+ alloc_size = *num_parts * sizeof(struct mtd_partition) +
+ extra_mem_size;
+ parts = kmalloc(alloc_size, GFP_KERNEL);
+ if (!parts)
+ {
+ printk(KERN_ERR ERRP "out of memory\n");
+ return NULL;
+ }
+ memset(parts, 0, alloc_size);
+ extra_mem = (unsigned char *)(parts + *num_parts);
+ }
+ /* enter this partition (offset will be calculated later if it is zero at this point) */
+ parts[this_part].size = size;
+ parts[this_part].offset = offset;
+ parts[this_part].mask_flags = mask_flags;
+ if (name)
+ {
+ strlcpy(extra_mem, name, name_len + 1);
+ }
+ else
+ {
+ sprintf(extra_mem, "Partition_%03d", this_part);
+ }
+ parts[this_part].name = extra_mem;
+ extra_mem += name_len + 1;
+
+ dbg(("partition %d: name <%s>, offset %x, size %x, mask flags %x\n",
+ this_part,
+ parts[this_part].name,
+ parts[this_part].offset,
+ parts[this_part].size,
+ parts[this_part].mask_flags));
+
+ /* return (updated) pointer to extra_mem memory */
+ if (extra_mem_ptr)
+ *extra_mem_ptr = extra_mem;
+
+ /* return (updated) pointer command line string */
+ *retptr = s;
+
+ /* return partition table */
+ return parts;
+}
+
+/*
+ * Parse the command line.
+ */
+static int mtdpart_setup_real(char *s)
+{
+ cmdline_parsed = 1;
+
+ for( ; s != NULL; )
+ {
+ struct cmdline_mtd_partition *this_mtd;
+ struct mtd_partition *parts;
+ int mtd_id_len;
+ int num_parts;
+ char *p, *mtd_id;
+
+ mtd_id = s;
+ /* fetch <mtd-id> */
+ if (!(p = strchr(s, ':')))
+ {
+ printk(KERN_ERR ERRP "no mtd-id\n");
+ return 0;
+ }
+ mtd_id_len = p - mtd_id;
+
+ dbg(("parsing <%s>\n", p+1));
+
+ /*
+ * parse one mtd. have it reserve memory for the
+ * struct cmdline_mtd_partition and the mtd-id string.
+ */
+ parts = newpart(p + 1, /* cmdline */
+ &s, /* out: updated cmdline ptr */
+ &num_parts, /* out: number of parts */
+ 0, /* first partition */
+ (unsigned char**)&this_mtd, /* out: extra mem */
+ mtd_id_len + 1 + sizeof(*this_mtd));
+ if(!parts)
+ {
+ /*
+ * An error occurred. We're either:
+ * a) out of memory, or
+ * b) in the middle of the partition spec
+ * Either way, this mtd is hosed and we're
+ * unlikely to succeed in parsing any more
+ */
+ return 0;
+ }
+
+ /* enter results */
+ this_mtd->parts = parts;
+ this_mtd->num_parts = num_parts;
+ this_mtd->mtd_id = (char*)(this_mtd + 1);
+ strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
+
+ /* link into chain */
+ this_mtd->next = partitions;
+ partitions = this_mtd;
+
+ dbg(("mtdid=<%s> num_parts=<%d>\n",
+ this_mtd->mtd_id, this_mtd->num_parts));
+
+
+ /* EOS - we're done */
+ if (*s == 0)
+ break;
+
+ /* does another spec follow? */
+ if (*s != ';')
+ {
+ printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
+ return 0;
+ }
+ s++;
+ }
+ return 1;
+}
+
+/*
+ * Main function to be called from the MTD mapping driver/device to
+ * obtain the partitioning information. At this point the command line
+ * arguments will actually be parsed and turned to struct mtd_partition
+ * information. It returns partitions for the requested mtd device, or
+ * the first one in the chain if a NULL mtd_id is passed in.
+ */
+static int parse_cmdline_partitions(struct mtd_info *master,
+ struct mtd_partition **pparts,
+ unsigned long origin)
+{
+ unsigned long offset;
+ int i;
+ struct cmdline_mtd_partition *part;
+ char *mtd_id = master->name;
+
+ if(!cmdline)
+ return -EINVAL;
+
+ /* parse command line */
+ if (!cmdline_parsed)
+ mtdpart_setup_real(cmdline);
+
+ for(part = partitions; part; part = part->next)
+ {
+ if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
+ {
+ for(i = 0, offset = 0; i < part->num_parts; i++)
+ {
+ if (!part->parts[i].offset)
+ part->parts[i].offset = offset;
+ else
+ offset = part->parts[i].offset;
+ if (part->parts[i].size == SIZE_REMAINING)
+ part->parts[i].size = master->size - offset;
+ if (offset + part->parts[i].size > master->size)
+ {
+ printk(KERN_WARNING ERRP
+ "%s: partitioning exceeds flash size, truncating\n",
+ part->mtd_id);
+ part->parts[i].size = master->size - offset;
+ part->num_parts = i;
+ }
+ offset += part->parts[i].size;
+ }
+ *pparts = part->parts;
+ return part->num_parts;
+ }
+ }
+ return -EINVAL;
+}
+
+
+/*
+ * This is the handler for our kernel parameter, called from
+ * main.c::checksetup(). Note that we can not yet kmalloc() anything,
+ * so we only save the commandline for later processing.
+ *
+ * This function needs to be visible for bootloaders.
+ */
+int mtdpart_setup(char *s)
+{
+ cmdline = s;
+ return 1;
+}
+
+__setup("mtdparts=", mtdpart_setup);
+
+static struct mtd_part_parser cmdline_parser = {
+ .owner = THIS_MODULE,
+ .parse_fn = parse_cmdline_partitions,
+ .name = "cmdlinepart",
+};
+
+static int __init cmdline_parser_init(void)
+{
+ return register_mtd_parser(&cmdline_parser);
+}
+
+module_init(cmdline_parser_init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
+MODULE_DESCRIPTION("Command line configuration of MTD partitions");
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