patch-2.4.21 linux-2.4.21/drivers/mtd/cmdlinepart.c

• Lines: 357
• Date: 2003-06-13 07:51:34.000000000 -0700
• Orig file: linux-2.4.20/drivers/mtd/cmdlinepart.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/drivers/mtd/cmdlinepart.c linux-2.4.21/drivers/mtd/cmdlinepart.c
@@ -0,0 +1,356 @@
+/*
+ * $Id: cmdlinepart.c,v 1.6 2002/11/16 01:37:39 dneuer 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 id used in mapping driver/device
+ * <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 <asm/setup.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 0xffffffff
+
+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 = 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 0;
+		}
+	}
+
+	/* 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 0;
+		}
+		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 0;
+		}
+		/* more partitions follow, parse them */
+		if ((parts = newpart(s + 1, &s, num_parts, 
+		                     this_part + 1, &extra_mem, extra_mem_size)) == 0)
+		  return 0;
+	}
+	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 0;
+		}
+		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)
+	{
+		strncpy(extra_mem, name, name_len);
+		extra_mem[name_len] = 0;
+	}
+	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);
+		strncpy(this_mtd->mtd_id, mtd_id, mtd_id_len);
+		this_mtd->mtd_id[mtd_id_len] = 0;
+
+		/* 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.
+ */
+int parse_cmdline_partitions(struct mtd_info *master, 
+                             struct mtd_partition **pparts,
+                             const char *mtd_id)
+{
+	unsigned long offset;
+	int i;
+	struct cmdline_mtd_partition *part;
+
+	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);
+
+EXPORT_SYMBOL(parse_cmdline_partitions);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Marius Groeger <mag@sysgo.de>");
+MODULE_DESCRIPTION("Command line configuration of MTD partitions");