1 files changed, 127 insertions, 0 deletions
diff --git a/block/partitions/blkdev_parts.c b/block/partitions/blkdev_parts.c
new file mode 100755
index 00000000000..030565b7ce7
--- /dev/null
+++ b/block/partitions/blkdev_parts.c
@@ -0,0 +1,127 @@
+/*
+ *
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Ulf Hansson <ulf.hansson@stericsson.com> for ST-Ericsson
+ * License terms: GNU General Public License (GPL) version 2
+ *
+ * Create partitions for block devices by reading from the kernel
+ * command line (kernel boot arguments).
+ *
+ */
+
+#include "check.h"
+#include "blkdev_parts.h"
+
+static char *cmdline;
+
+/*
+ * This is the handler for our kernel commandline 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 cmdline_setup(char *s)
+{
+	cmdline = s;
+	return 1;
+}
+__setup("blkdevparts=", cmdline_setup);
+
+/* Parse for a matching blkdev-id and return pointer to partdef */
+static char *parse_blkdev_id(char *blkdev_name)
+{
+	int blkdev_id_len;
+	char *p, *blkdev_id;
+
+	/* Start parsing for a matching blkdev-id */
+	p = blkdev_id = cmdline;
+	while (blkdev_id != NULL) {
+
+		/* Find the end of the blkdev-id string */
+		p = strchr(blkdev_id, ':');
+		if (p == NULL)
+			return NULL;
+
+		/* Check if we found a matching blkdev-id */
+		blkdev_id_len = p - blkdev_id;
+		if (strlen(blkdev_name)	== blkdev_id_len) {
+			if (strncmp(blkdev_name, blkdev_id, blkdev_id_len) == 0)
+				return p;
+		}
+
+		/* Move to next blkdev-id string if there is one */
+		blkdev_id = strchr(p, ';');
+		if (blkdev_id != NULL)
+			blkdev_id++;
+	}
+	return NULL;
+}
+
+static int parse_partdef(char **part, struct parsed_partitions *state, int part_nbr)
+{
+	sector_t size, offset;
+	char *p = *part;
+
+	/* Skip the beginning "," or ":" */
+	p++;
+
+	/* Fetch and verify size from partdef */
+	size = simple_strtoull(p, &p, 10);
+	if ((size == 0) || (*p != '@'))
+		return 0;
+
+	/* Skip the "@" */
+	p++;
+
+	/* Fetch offset from partdef and check if there are more parts */
+	offset = simple_strtoull(p, &p, 10);
+	if (*p == ',')
+		*part = p;
+	else
+		*part = NULL;
+
+	/* Add partition to state */
+	put_partition(state, part_nbr, offset, size);
+	printk(KERN_INFO "\nPartition: size=%llu, offset=%llu\n",
+		(unsigned long long) size,
+		(unsigned long long) offset);
+	return 1;
+}
+
+static int parse_blkdev_parts(char *blkdev_name, struct parsed_partitions *state)
+{
+	char *partdef;
+	int part_nbr = 0;
+
+	/* Find partdef */
+	partdef = parse_blkdev_id(blkdev_name);
+
+	/* Add parts */
+	while (partdef != NULL) {
+		/* Find next part and add it to state */
+		part_nbr++;
+		if (!parse_partdef(&partdef, state, part_nbr))
+			return 0;
+	}
+	return part_nbr;
+}
+
+int blkdev_partition(struct parsed_partitions *state)
+{
+	char blkdev_name[BDEVNAME_SIZE];
+
+	/* Check if there are any partitions to handle */
+	if (cmdline == NULL)
+		return 0;
+
+	/* Get the name of the blockdevice we are operating upon */
+	if (bdevname(state->bdev, blkdev_name) == NULL) {
+		printk(KERN_WARNING "Could not get a blkdev name\n");
+		return 0;
+	}
+
+	/* Parse for partitions and add them to the state */
+	return parse_blkdev_parts(blkdev_name, state);
+}
+