[PATCH] partitions: Read Rio Karma partition table

The Rio Karma portable MP3 player has its own proprietary partition table.

The partition layout is similar to a DOS boot sector but it begins at a
different offset and uses a different magic number (0xAB56 instead of
0xAA55).  Add support for it to enable mounting the device.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/partitions/Kconfig

@@ -222,6 +222,13 @@ config SUN_PARTITION
 	  given by the tar program ("man tar" or preferably "info tar"). If
 	  you don't know what all this is about, say N.
 
+config KARMA_PARTITION
+	bool "Karma Partition support"
+	depends on PARTITION_ADVANCED
+	help
+	  Say Y here if you would like to mount the Rio Karma MP3 player, as it
+	  uses a proprietary partition table.
+
 config EFI_PARTITION
 	bool "EFI GUID Partition support"
 	depends on PARTITION_ADVANCED

fs/partitions/Makefile

@@ -17,3 +17,4 @@ obj-$(CONFIG_SUN_PARTITION) += sun.o
 obj-$(CONFIG_ULTRIX_PARTITION) += ultrix.o
 obj-$(CONFIG_IBM_PARTITION) += ibm.o
 obj-$(CONFIG_EFI_PARTITION) += efi.o
+obj-$(CONFIG_KARMA_PARTITION) += karma.o

fs/partitions/check.c

@@ -35,6 +35,7 @@
 #include "ibm.h"
 #include "ultrix.h"
 #include "efi.h"
+#include "karma.h"
 
 #ifdef CONFIG_BLK_DEV_MD
 extern void md_autodetect_dev(dev_t dev);
@@ -102,6 +103,9 @@ static int (*check_part[])(struct parsed_partitions *, struct block_device *) =
 #endif
 #ifdef CONFIG_IBM_PARTITION
 	ibm_partition,
+#endif
+#ifdef CONFIG_KARMA_PARTITION
+	karma_partition,
 #endif
 	NULL
 };

fs/partitions/karma.c

+/*
+ *  fs/partitions/karma.c
+ *  Rio Karma partition info.
+ *
+ *  Copyright (C) 2006 Bob Copeland (me@bobcopeland.com)
+ *  based on osf.c
+ */
+
+#include "check.h"
+#include "karma.h"
+
+int karma_partition(struct parsed_partitions *state, struct block_device *bdev)
+{
+	int i;
+	int slot = 1;
+	Sector sect;
+	unsigned char *data;
+	struct disklabel {
+		u8 d_reserved[270];
+		struct d_partition {
+			__le32 p_res;
+			u8 p_fstype;
+			u8 p_res2[3];
+			__le32 p_offset;
+			__le32 p_size;
+		} d_partitions[2];
+		u8 d_blank[208];
+		__le16 d_magic;
+	} __attribute__((packed)) *label;
+	struct d_partition *p;
+
+	data = read_dev_sector(bdev, 0, &sect);
+	if (!data)
+		return -1;
+
+	label = (struct disklabel *)data;
+	if (le16_to_cpu(label->d_magic) != KARMA_LABEL_MAGIC) {
+		put_dev_sector(sect);
+		return 0;
+	}
+
+	p = label->d_partitions;
+	for (i = 0 ; i < 2; i++, p++) {
+		if (slot == state->limit)
+			break;
+
+		if (p->p_fstype == 0x4d && le32_to_cpu(p->p_size)) {
+			put_partition(state, slot, le32_to_cpu(p->p_offset),
+				le32_to_cpu(p->p_size));
+		}
+		slot++;
+	}
+	printk("\n");
+	put_dev_sector(sect);
+	return 1;
+}
+

fs/partitions/karma.h

+/*
+ *  fs/partitions/karma.h
+ */
+
+#define KARMA_LABEL_MAGIC		0xAB56
+
+int karma_partition(struct parsed_partitions *state, struct block_device *bdev);
+