drivers/mtd/cmdlinepart.c - kernel/prism - Git at Google

 /*
  * 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>]
  *              where <mtd-id> is the name from the "cat /proc/mtd" command
  * <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
  * <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 UINT_MAX
 #define OFFSET_CONTINUOUS UINT_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_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 = 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 (%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;
 		p = strchr(name, delim);
 		if (!p)
 		{
 			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;
         }

         /* 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 NULL;
 		}
 		/* more partitions follow, parse them */
 		parts = newpart(s + 1, &s, num_parts, this_part + 1,
 				&extra_mem, extra_mem_size);
 		if (!parts)
 			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 = kzalloc(alloc_size, GFP_KERNEL);
 		if (!parts)
 		{
 			printk(KERN_ERR ERRP "out of memory\n");
 			return NULL;
 		}
 		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;
 		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) +
 				sizeof(void*)-1 /*alignment*/);
 		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;
 		 }

 		/* 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 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,
                              const char *cmd)
 {
 	unsigned long offset;
 	int i;
 	struct cmdline_mtd_partition *part;
 	const char *mtd_id = master->name;

 	if (cmd!="") {
 		cmdline = cmd;
 		cmdline_parsed = 0;
 	}

 	/* 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 == 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;
 					part->num_parts = i;
 				}
 				offset += part->parts[i].size;
 			}
 			*pparts = kmemdup(part->parts,
 					sizeof(*part->parts) * part->num_parts,
 					GFP_KERNEL);
 			if (!*pparts)
 				return -ENOMEM;
 			return part->num_parts;
 		}
 	}
 	return 0;
 }


 /*
  * 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 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");
	/*
	* 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>]
	* where <mtd-id> is the name from the "cat /proc/mtd" command
	* <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
	* <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 UINT_MAX
	#define OFFSET_CONTINUOUS UINT_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_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 = 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 (%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;
	p = strchr(name, delim);
	if (!p)
	{
	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;
	}

	/* 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 NULL;
	}
	/* more partitions follow, parse them */
	parts = newpart(s + 1, &s, num_parts, this_part + 1,
	&extra_mem, extra_mem_size);
	if (!parts)
	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 = kzalloc(alloc_size, GFP_KERNEL);
	if (!parts)
	{
	printk(KERN_ERR ERRP "out of memory\n");
	return NULL;
	}
	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;
	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) +
	sizeof(void)-1 /alignment*/);
	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;
	}

	/* 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 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,
	const char *cmd)
	{
	unsigned long offset;
	int i;
	struct cmdline_mtd_partition *part;
	const char *mtd_id = master->name;

	if (cmd!="") {
	cmdline = cmd;
	cmdline_parsed = 0;
	}

	/* 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 == 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;
	part->num_parts = i;
	}
	offset += part->parts[i].size;
	}
	*pparts = kmemdup(part->parts,
	sizeof(part->parts) part->num_parts,
	GFP_KERNEL);
	if (!*pparts)
	return -ENOMEM;
	return part->num_parts;
	}
	}
	return 0;
	}


	/*
	* 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 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");