--- /dev/null
+/*
+ * Read flash partition table from command line
+ *
+ * Copyright © 2002 SYSGO Real-Time Solutions GmbH
+ * Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * The format for the command line is as follows:
+ *
+ * mtdparts=<mtddef>[;<mtddef]
+ * <mtddef> := <mtd-id>:<partdef>[,<partdef>]
+ * <partdef> := <size>[@<offset>][<name>][ro][lk]
+ * <mtd-id> := unique name used in mapping driver/device (mtd->name)
+ * <size> := standard linux memsize OR "-" to denote all remaining space
+ * size is automatically truncated at end of device
+ * if specified or truncated size is 0 the part is skipped
+ * <offset> := standard linux memsize
+ * if omitted the part will immediately follow the previous part
+ * or 0 if the first part
+ * <name> := '(' NAME ')'
+ * NAME will appear in /proc/mtd
+ *
+ * <size> and <offset> can be specified such that the parts are out of order
+ * in physical memory and may even overlap.
+ *
+ * The parts are assigned MTD numbers in the order they are specified in the
+ * command line regardless of their order in physical memory.
+ *
+ * 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/module.h>
+#include <linux/err.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 ULLONG_MAX
+#define OFFSET_CONTINUOUS ULLONG_MAX
+
+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_setup() */
+static char *mtdparts;
+static char *cmdline;
+static int cmdline_parsed;
+
+/*
+ * 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 long size, offset = OFFSET_CONTINUOUS;
+ 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 (%llx)\n",
+ size);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ /* 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;
+ p = strchr(name, delim);
+ if (!p) {
+ printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
+ return ERR_PTR(-EINVAL);
+ }
+ 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;
+ }
+
+ /* if lk is found do NOT unlock the MTD partition*/
+ if (strncmp(s, "lk", 2) == 0) {
+ mask_flags |= MTD_POWERUP_LOCK;
+ 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 ERR_PTR(-EINVAL);
+ }
+ /* more partitions follow, parse them */
+ parts = newpart(s + 1, &s, num_parts, this_part + 1,
+ &extra_mem, extra_mem_size);
+ if (IS_ERR(parts))
+ return parts;
+ } 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 = kzalloc(alloc_size, GFP_KERNEL);
+ if (!parts)
+ return ERR_PTR(-ENOMEM);
+ 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 %llx, size %llx, 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, num_parts;
+ char *p, *mtd_id;
+
+ mtd_id = s;
+
+ /* fetch <mtd-id> */
+ p = strchr(s, ':');
+ if (!p) {
+ printk(KERN_ERR ERRP "no mtd-id\n");
+ return -EINVAL;
+ }
+ 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) +
+ sizeof(void*)-1 /*alignment*/);
+ if (IS_ERR(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 PTR_ERR(parts);
+ }
+
+ /* align this_mtd */
+ this_mtd = (struct cmdline_mtd_partition *)
+ ALIGN((unsigned long)this_mtd, sizeof(void *));
+ /* 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 -EINVAL;
+ }
+ s++;
+ }
+
+ return 0;
+}
+
+/*
+ * 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,
+ struct mtd_part_parser_data *data)
+{
+ unsigned long long offset;
+ int i, err;
+ struct cmdline_mtd_partition *part;
+ const char *mtd_id = master->name;
+
+ /* parse command line */
+ if (!cmdline_parsed) {
+ err = mtdpart_setup_real(cmdline);
+ if (err)
+ return err;
+ }
+
+ /*
+ * Search for the partition definition matching master->name.
+ * If master->name is not set, stop at first partition definition.
+ */
+ for (part = partitions; part; part = part->next) {
+ if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
+ break;
+ }
+
+ if (!part)
+ return 0;
+
+ for (i = 0, offset = 0; i < part->num_parts; i++) {
+ if (part->parts[i].offset == OFFSET_CONTINUOUS)
+ 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;
+ }
+ offset += part->parts[i].size;
+
+ if (part->parts[i].size == 0) {
+ printk(KERN_WARNING ERRP
+ "%s: skipping zero sized partition\n",
+ part->mtd_id);
+ part->num_parts--;
+ memmove(&part->parts[i], &part->parts[i + 1],
+ sizeof(*part->parts) * (part->num_parts - i));
+ i--;
+ }
+ }
+
+ *pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts,
+ GFP_KERNEL);
+ if (!*pparts)
+ return -ENOMEM;
+
+ return part->num_parts;
+}
+
+
+/*
+ * 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.
+ */
+static int __init 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)
+{
+ if (mtdparts)
+ mtdpart_setup(mtdparts);
+ register_mtd_parser(&cmdline_parser);
+ return 0;
+}
+
+static void __exit cmdline_parser_exit(void)
+{
+ deregister_mtd_parser(&cmdline_parser);
+}
+
+module_init(cmdline_parser_init);
+module_exit(cmdline_parser_exit);
+
+MODULE_PARM_DESC(mtdparts, "Partitioning specification");
+module_param(mtdparts, charp, 0);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
+MODULE_DESCRIPTION("Command line configuration of MTD partitions");
Code Review / kvmfornfv.git / blobdiff