376 lines
9.0 KiB
C
376 lines
9.0 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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*
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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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* <name> := '(' NAME ')'
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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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#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/bootmem.h>
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/* error message prefix */
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#define ERRP "mtd: "
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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 UINT_MAX
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#define OFFSET_CONTINUOUS UINT_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_setupd() */
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static char *cmdline;
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static int cmdline_parsed = 0;
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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 size;
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unsigned long 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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}
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else
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{
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size = memparse(s, &s);
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if (size < PAGE_SIZE)
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{
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printk(KERN_ERR ERRP "partition size too small (%lx)\n", size);
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return NULL;
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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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{
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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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{
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delim = ')';
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}
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if (delim)
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{
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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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{
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printk(KERN_ERR ERRP "no closing %c found in partition name\n", delim);
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return NULL;
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}
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name_len = p - name;
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s = p + 1;
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}
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else
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{
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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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{
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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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{
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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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{
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if (size == SIZE_REMAINING)
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{
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printk(KERN_ERR ERRP "no partitions allowed after a fill-up partition\n");
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return NULL;
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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 (!parts)
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return NULL;
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}
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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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{
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printk(KERN_ERR ERRP "out of memory\n");
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return NULL;
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}
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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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{
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strlcpy(extra_mem, name, name_len + 1);
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}
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else
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{
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sprintf(extra_mem, "Partition_%03d", this_part);
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}
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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 %x, size %x, mask flags %x\n",
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this_part,
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parts[this_part].name,
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parts[this_part].offset,
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parts[this_part].size,
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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;
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int 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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if (!(p = strchr(s, ':')))
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{
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printk(KERN_ERR ERRP "no mtd-id\n");
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return 0;
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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(!parts)
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{
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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 0;
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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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{
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printk(KERN_ERR ERRP "bad character after partition (%c)\n", *s);
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return 0;
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}
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s++;
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}
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return 1;
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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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struct mtd_partition **pparts,
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unsigned long origin)
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{
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unsigned long offset;
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int i;
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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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mtdpart_setup_real(cmdline);
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for(part = partitions; part; part = part->next)
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{
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if ((!mtd_id) || (!strcmp(part->mtd_id, mtd_id)))
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{
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for(i = 0, offset = 0; i < part->num_parts; i++)
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{
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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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{
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printk(KERN_WARNING ERRP
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"%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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part->num_parts = i;
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}
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offset += part->parts[i].size;
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}
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*pparts = part->parts;
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return part->num_parts;
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}
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}
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return 0;
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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 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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.owner = THIS_MODULE,
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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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return register_mtd_parser(&cmdline_parser);
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}
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module_init(cmdline_parser_init);
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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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