/* * $Id: cmdlinepart.c,v 1.2 2007/09/21 03:09:24 quy 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 0xffffffffstruct 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. */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){	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");