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![Brian Norris](/assets/img/avatar_default.png)
We only want to modify these arrays inside the parser "drivers", so the drivers should construct them however they like, then return them as immutable arrays. This will make other refactorings easier. Signed-off-by: Brian Norris <computersforpeace@gmail.com> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
410 lines
11 KiB
C
410 lines
11 KiB
C
/*
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* Read flash partition table from command line
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*
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* Copyright © 2002 SYSGO Real-Time Solutions GmbH
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* Copyright © 2002-2010 David Woodhouse <dwmw2@infradead.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* The format for the command line is as follows:
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*
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* mtdparts=<mtddef>[;<mtddef]
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* <mtddef> := <mtd-id>:<partdef>[,<partdef>]
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* <partdef> := <size>[@<offset>][<name>][ro][lk]
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* <mtd-id> := unique name used in mapping driver/device (mtd->name)
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* <size> := standard linux memsize OR "-" to denote all remaining space
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* size is automatically truncated at end of device
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* if specified or truncated size is 0 the part is skipped
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* <offset> := standard linux memsize
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* if omitted the part will immediately follow the previous part
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* or 0 if the first part
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* <name> := '(' NAME ')'
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* NAME will appear in /proc/mtd
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*
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* <size> and <offset> can be specified such that the parts are out of order
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* in physical memory and may even overlap.
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*
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* The parts are assigned MTD numbers in the order they are specified in the
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* command line regardless of their order in physical memory.
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*
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* Examples:
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*
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* 1 NOR Flash, with 1 single writable partition:
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* edb7312-nor:-
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*
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* 1 NOR Flash with 2 partitions, 1 NAND with one
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* edb7312-nor:256k(ARMboot)ro,-(root);edb7312-nand:-(home)
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*/
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#define pr_fmt(fmt) "mtd: " fmt
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/mtd/mtd.h>
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#include <linux/mtd/partitions.h>
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#include <linux/module.h>
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#include <linux/err.h>
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/* debug macro */
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#if 0
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#define dbg(x) do { printk("DEBUG-CMDLINE-PART: "); printk x; } while(0)
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#else
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#define dbg(x)
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#endif
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/* special size referring to all the remaining space in a partition */
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#define SIZE_REMAINING ULLONG_MAX
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#define OFFSET_CONTINUOUS ULLONG_MAX
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struct cmdline_mtd_partition {
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struct cmdline_mtd_partition *next;
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char *mtd_id;
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int num_parts;
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struct mtd_partition *parts;
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};
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/* mtdpart_setup() parses into here */
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static struct cmdline_mtd_partition *partitions;
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/* the command line passed to mtdpart_setup() */
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static char *mtdparts;
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static char *cmdline;
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static int cmdline_parsed;
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/*
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* Parse one partition definition for an MTD. Since there can be many
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* comma separated partition definitions, this function calls itself
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* recursively until no more partition definitions are found. Nice side
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* effect: the memory to keep the mtd_partition structs and the names
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* is allocated upon the last definition being found. At that point the
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* syntax has been verified ok.
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*/
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static struct mtd_partition * newpart(char *s,
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char **retptr,
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int *num_parts,
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int this_part,
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unsigned char **extra_mem_ptr,
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int extra_mem_size)
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{
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struct mtd_partition *parts;
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unsigned long long size, offset = OFFSET_CONTINUOUS;
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char *name;
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int name_len;
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unsigned char *extra_mem;
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char delim;
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unsigned int mask_flags;
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/* fetch the partition size */
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if (*s == '-') {
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/* assign all remaining space to this partition */
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size = SIZE_REMAINING;
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s++;
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} else {
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size = memparse(s, &s);
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if (!size) {
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pr_err("partition has size 0\n");
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return ERR_PTR(-EINVAL);
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}
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}
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/* fetch partition name and flags */
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mask_flags = 0; /* this is going to be a regular partition */
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delim = 0;
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/* check for offset */
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if (*s == '@') {
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s++;
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offset = memparse(s, &s);
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}
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/* now look for name */
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if (*s == '(')
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delim = ')';
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if (delim) {
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char *p;
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name = ++s;
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p = strchr(name, delim);
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if (!p) {
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pr_err("no closing %c found in partition name\n", delim);
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return ERR_PTR(-EINVAL);
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}
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name_len = p - name;
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s = p + 1;
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} else {
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name = NULL;
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name_len = 13; /* Partition_000 */
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}
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/* record name length for memory allocation later */
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extra_mem_size += name_len + 1;
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/* test for options */
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if (strncmp(s, "ro", 2) == 0) {
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mask_flags |= MTD_WRITEABLE;
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s += 2;
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}
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/* if lk is found do NOT unlock the MTD partition*/
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if (strncmp(s, "lk", 2) == 0) {
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mask_flags |= MTD_POWERUP_LOCK;
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s += 2;
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}
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/* test if more partitions are following */
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if (*s == ',') {
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if (size == SIZE_REMAINING) {
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pr_err("no partitions allowed after a fill-up partition\n");
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return ERR_PTR(-EINVAL);
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}
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/* more partitions follow, parse them */
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parts = newpart(s + 1, &s, num_parts, this_part + 1,
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&extra_mem, extra_mem_size);
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if (IS_ERR(parts))
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return parts;
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} else {
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/* this is the last partition: allocate space for all */
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int alloc_size;
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*num_parts = this_part + 1;
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alloc_size = *num_parts * sizeof(struct mtd_partition) +
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extra_mem_size;
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parts = kzalloc(alloc_size, GFP_KERNEL);
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if (!parts)
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return ERR_PTR(-ENOMEM);
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extra_mem = (unsigned char *)(parts + *num_parts);
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}
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/* enter this partition (offset will be calculated later if it is zero at this point) */
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parts[this_part].size = size;
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parts[this_part].offset = offset;
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parts[this_part].mask_flags = mask_flags;
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if (name)
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strlcpy(extra_mem, name, name_len + 1);
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else
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sprintf(extra_mem, "Partition_%03d", this_part);
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parts[this_part].name = extra_mem;
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extra_mem += name_len + 1;
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dbg(("partition %d: name <%s>, offset %llx, size %llx, mask flags %x\n",
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this_part, parts[this_part].name, parts[this_part].offset,
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parts[this_part].size, parts[this_part].mask_flags));
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/* return (updated) pointer to extra_mem memory */
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if (extra_mem_ptr)
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*extra_mem_ptr = extra_mem;
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/* return (updated) pointer command line string */
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*retptr = s;
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/* return partition table */
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return parts;
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}
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/*
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* Parse the command line.
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*/
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static int mtdpart_setup_real(char *s)
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{
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cmdline_parsed = 1;
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for( ; s != NULL; )
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{
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struct cmdline_mtd_partition *this_mtd;
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struct mtd_partition *parts;
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int mtd_id_len, num_parts;
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char *p, *mtd_id;
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mtd_id = s;
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/* fetch <mtd-id> */
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p = strchr(s, ':');
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if (!p) {
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pr_err("no mtd-id\n");
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return -EINVAL;
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}
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mtd_id_len = p - mtd_id;
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dbg(("parsing <%s>\n", p+1));
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/*
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* parse one mtd. have it reserve memory for the
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* struct cmdline_mtd_partition and the mtd-id string.
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*/
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parts = newpart(p + 1, /* cmdline */
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&s, /* out: updated cmdline ptr */
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&num_parts, /* out: number of parts */
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0, /* first partition */
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(unsigned char**)&this_mtd, /* out: extra mem */
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mtd_id_len + 1 + sizeof(*this_mtd) +
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sizeof(void*)-1 /*alignment*/);
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if (IS_ERR(parts)) {
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/*
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* An error occurred. We're either:
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* a) out of memory, or
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* b) in the middle of the partition spec
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* Either way, this mtd is hosed and we're
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* unlikely to succeed in parsing any more
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*/
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return PTR_ERR(parts);
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}
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/* align this_mtd */
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this_mtd = (struct cmdline_mtd_partition *)
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ALIGN((unsigned long)this_mtd, sizeof(void *));
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/* enter results */
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this_mtd->parts = parts;
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this_mtd->num_parts = num_parts;
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this_mtd->mtd_id = (char*)(this_mtd + 1);
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strlcpy(this_mtd->mtd_id, mtd_id, mtd_id_len + 1);
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/* link into chain */
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this_mtd->next = partitions;
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partitions = this_mtd;
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dbg(("mtdid=<%s> num_parts=<%d>\n",
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this_mtd->mtd_id, this_mtd->num_parts));
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/* EOS - we're done */
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if (*s == 0)
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break;
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/* does another spec follow? */
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if (*s != ';') {
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pr_err("bad character after partition (%c)\n", *s);
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return -EINVAL;
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}
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s++;
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}
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return 0;
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}
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/*
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* Main function to be called from the MTD mapping driver/device to
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* obtain the partitioning information. At this point the command line
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* arguments will actually be parsed and turned to struct mtd_partition
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* information. It returns partitions for the requested mtd device, or
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* the first one in the chain if a NULL mtd_id is passed in.
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*/
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static int parse_cmdline_partitions(struct mtd_info *master,
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const struct mtd_partition **pparts,
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struct mtd_part_parser_data *data)
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{
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unsigned long long offset;
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int i, err;
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struct cmdline_mtd_partition *part;
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const char *mtd_id = master->name;
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/* parse command line */
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if (!cmdline_parsed) {
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err = mtdpart_setup_real(cmdline);
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if (err)
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return err;
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}
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/*
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* Search for the partition definition matching master->name.
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* If master->name is not set, stop at first partition definition.
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*/
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for (part = partitions; part; part = part->next) {
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if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
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break;
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}
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if (!part)
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return 0;
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for (i = 0, offset = 0; i < part->num_parts; i++) {
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if (part->parts[i].offset == OFFSET_CONTINUOUS)
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part->parts[i].offset = offset;
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else
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offset = part->parts[i].offset;
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if (part->parts[i].size == SIZE_REMAINING)
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part->parts[i].size = master->size - offset;
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if (offset + part->parts[i].size > master->size) {
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pr_warn("%s: partitioning exceeds flash size, truncating\n",
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part->mtd_id);
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part->parts[i].size = master->size - offset;
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}
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offset += part->parts[i].size;
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if (part->parts[i].size == 0) {
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pr_warn("%s: skipping zero sized partition\n",
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part->mtd_id);
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part->num_parts--;
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memmove(&part->parts[i], &part->parts[i + 1],
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sizeof(*part->parts) * (part->num_parts - i));
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i--;
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}
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}
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*pparts = kmemdup(part->parts, sizeof(*part->parts) * part->num_parts,
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GFP_KERNEL);
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if (!*pparts)
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return -ENOMEM;
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return part->num_parts;
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}
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/*
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* This is the handler for our kernel parameter, called from
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* main.c::checksetup(). Note that we can not yet kmalloc() anything,
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* so we only save the commandline for later processing.
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*
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* This function needs to be visible for bootloaders.
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*/
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static int __init mtdpart_setup(char *s)
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{
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cmdline = s;
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return 1;
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}
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__setup("mtdparts=", mtdpart_setup);
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static struct mtd_part_parser cmdline_parser = {
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.parse_fn = parse_cmdline_partitions,
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.name = "cmdlinepart",
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};
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static int __init cmdline_parser_init(void)
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{
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if (mtdparts)
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mtdpart_setup(mtdparts);
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register_mtd_parser(&cmdline_parser);
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return 0;
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}
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static void __exit cmdline_parser_exit(void)
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{
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deregister_mtd_parser(&cmdline_parser);
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}
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module_init(cmdline_parser_init);
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module_exit(cmdline_parser_exit);
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MODULE_PARM_DESC(mtdparts, "Partitioning specification");
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module_param(mtdparts, charp, 0);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
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MODULE_DESCRIPTION("Command line configuration of MTD partitions");
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