kernel/3.1[02]: move MTD root device setup code to mtdcore

The current code only allows to automatically set
root device on MTD partitions. Move the code to MTD
core to allow to use it with all MTD devices.

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38643 3c298f89-4303-0410-b956-a3cf2f4a3e73

16 files changed, 94 insertions, 58 deletions

diff --git a/target/linux/generic/patches-3.10/400-mtd-add-rootfs-split-support.patch b/target/linux/generic/patches-3.10/400-mtd-add-rootfs-split-support.patch
index 6a4c16134e9..6c17b01e53e 100644
--- a/target/linux/generic/patches-3.10/400-mtd-add-rootfs-split-support.patch
+++ b/target/linux/generic/patches-3.10/400-mtd-add-rootfs-split-support.patch
@@ -35,16 +35,15 @@
  	depends on m
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -29,6 +29,8 @@
+@@ -29,6 +29,7 @@
  #include <linux/kmod.h>
  #include <linux/mtd/mtd.h>
  #include <linux/mtd/partitions.h>
-+#include <linux/root_dev.h>
 +#include <linux/magic.h>
  #include <linux/err.h>
  
  #include "mtdcore.h"
-@@ -45,13 +47,14 @@ struct mtd_part {
+@@ -45,13 +46,14 @@ struct mtd_part {
  	struct list_head list;
  };
  
@@ -60,7 +59,7 @@
  /*
   * MTD methods which simply translate the effective address and pass through
   * to the _real_ device.
-@@ -533,8 +536,10 @@ out_register:
+@@ -533,8 +535,10 @@ out_register:
  	return slave;
  }
  
@@ -73,7 +72,7 @@
  {
  	struct mtd_partition part;
  	struct mtd_part *p, *new;
-@@ -566,21 +571,24 @@ int mtd_add_partition(struct mtd_info *m
+@@ -566,21 +570,24 @@ int mtd_add_partition(struct mtd_info *m
  	end = offset + length;
  
  	mutex_lock(&mtd_partitions_mutex);
@@ -108,7 +107,7 @@
  
  	return ret;
  err_inv:
-@@ -590,6 +598,12 @@ err_inv:
+@@ -590,6 +597,12 @@ err_inv:
  }
  EXPORT_SYMBOL_GPL(mtd_add_partition);
  
@@ -121,7 +120,7 @@
  int mtd_del_partition(struct mtd_info *master, int partno)
  {
  	struct mtd_part *slave, *next;
-@@ -613,6 +627,151 @@ int mtd_del_partition(struct mtd_info *m
+@@ -613,6 +626,144 @@ int mtd_del_partition(struct mtd_info *m
  }
  EXPORT_SYMBOL_GPL(mtd_del_partition);
  
@@ -252,13 +251,6 @@
 +	if (!strcmp(part->mtd.name, "rootfs")) {
 +		rootfs_found = 1;
 +
-+		if (config_enabled(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
-+		    ROOT_DEV == 0) {
-+			printk(KERN_NOTICE "mtd: partition \"rootfs\" "
-+				"set to be root filesystem\n");
-+			ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, part->mtd.index);
-+		}
-+
 +		if (config_enabled(CONFIG_MTD_ROOTFS_SPLIT))
 +			split_rootfs_data(master, part);
 +	}
@@ -273,7 +265,7 @@
  /*
   * This function, given a master MTD object and a partition table, creates
   * and registers slave MTD objects which are bound to the master according to
-@@ -642,6 +801,7 @@ int add_mtd_partitions(struct mtd_info *
+@@ -642,6 +793,7 @@ int add_mtd_partitions(struct mtd_info *
  		mutex_unlock(&mtd_partitions_mutex);
  
  		add_mtd_device(&slave->mtd);
diff --git a/target/linux/generic/patches-3.10/401-mtd-add-support-for-different-partition-parser-types.patch b/target/linux/generic/patches-3.10/401-mtd-add-support-for-different-partition-parser-types.patch
index 8ac084d5e1f..bd35aa7d353 100644
--- a/target/linux/generic/patches-3.10/401-mtd-add-support-for-different-partition-parser-types.patch
+++ b/target/linux/generic/patches-3.10/401-mtd-add-support-for-different-partition-parser-types.patch
@@ -11,7 +11,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
 
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -831,6 +831,30 @@ static struct mtd_part_parser *get_parti
+@@ -823,6 +823,30 @@ static struct mtd_part_parser *get_parti
  
  #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
  
@@ -42,7 +42,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  int register_mtd_parser(struct mtd_part_parser *p)
  {
  	spin_lock(&part_parser_lock);
-@@ -907,6 +931,38 @@ int parse_mtd_partitions(struct mtd_info
+@@ -899,6 +923,38 @@ int parse_mtd_partitions(struct mtd_info
  	return ret;
  }
  
diff --git a/target/linux/generic/patches-3.10/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch b/target/linux/generic/patches-3.10/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch
index a614094851c..649693ff22c 100644
--- a/target/linux/generic/patches-3.10/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch
+++ b/target/linux/generic/patches-3.10/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -627,6 +627,37 @@ int mtd_del_partition(struct mtd_info *m
+@@ -626,6 +626,37 @@ int mtd_del_partition(struct mtd_info *m
  }
  EXPORT_SYMBOL_GPL(mtd_del_partition);
  
@@ -38,7 +38,7 @@
  static inline unsigned long
  mtd_pad_erasesize(struct mtd_info *mtd, int offset, int len)
  {
-@@ -686,6 +717,10 @@ static void split_rootfs_data(struct mtd
+@@ -685,6 +716,10 @@ static void split_rootfs_data(struct mtd
  	unsigned int split_size;
  	int ret;
  
@@ -49,7 +49,7 @@
  	ret = split_squashfs(master, part->offset, &split_offset);
  	if (ret)
  		return;
-@@ -735,6 +770,12 @@ static void split_uimage(struct mtd_info
+@@ -734,6 +769,12 @@ static void split_uimage(struct mtd_info
  
  static void split_firmware(struct mtd_info *master, struct mtd_part *part)
  {
diff --git a/target/linux/generic/patches-3.10/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch b/target/linux/generic/patches-3.10/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch
index 43960b3065a..9024026c9c6 100644
--- a/target/linux/generic/patches-3.10/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch
+++ b/target/linux/generic/patches-3.10/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -34,6 +34,7 @@
+@@ -33,6 +33,7 @@
  #include <linux/err.h>
  
  #include "mtdcore.h"
@@ -8,7 +8,7 @@
  
  /* Our partition linked list */
  static LIST_HEAD(mtd_partitions);
-@@ -669,43 +670,16 @@ mtd_pad_erasesize(struct mtd_info *mtd,
+@@ -668,43 +669,16 @@ mtd_pad_erasesize(struct mtd_info *mtd,
  	return len;
  }
  
diff --git a/target/linux/generic/patches-3.10/405-mtd-add-more-helper-functions.patch b/target/linux/generic/patches-3.10/405-mtd-add-more-helper-functions.patch
index 97ad2db87e5..9c75e5cb15a 100644
--- a/target/linux/generic/patches-3.10/405-mtd-add-more-helper-functions.patch
+++ b/target/linux/generic/patches-3.10/405-mtd-add-more-helper-functions.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -435,14 +435,12 @@ static struct mtd_part *allocate_partiti
+@@ -434,14 +434,12 @@ static struct mtd_part *allocate_partiti
  	if (slave->offset == MTDPART_OFS_APPEND)
  		slave->offset = cur_offset;
  	if (slave->offset == MTDPART_OFS_NXTBLK) {
@@ -18,7 +18,7 @@
  	}
  	if (slave->offset == MTDPART_OFS_RETAIN) {
  		slave->offset = cur_offset;
-@@ -995,6 +993,24 @@ int mtd_is_partition(const struct mtd_in
+@@ -987,6 +985,24 @@ int mtd_is_partition(const struct mtd_in
  }
  EXPORT_SYMBOL_GPL(mtd_is_partition);
  
diff --git a/target/linux/generic/patches-3.10/411-mtd-partial_eraseblock_write.patch b/target/linux/generic/patches-3.10/411-mtd-partial_eraseblock_write.patch
index 560096f854b..b7152110b29 100644
--- a/target/linux/generic/patches-3.10/411-mtd-partial_eraseblock_write.patch
+++ b/target/linux/generic/patches-3.10/411-mtd-partial_eraseblock_write.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -36,6 +36,8 @@
+@@ -35,6 +35,8 @@
  #include "mtdcore.h"
  #include "mtdsplit.h"
  
@@ -9,7 +9,7 @@
  /* Our partition linked list */
  static LIST_HEAD(mtd_partitions);
  static DEFINE_MUTEX(mtd_partitions_mutex);
-@@ -232,13 +234,60 @@ static int part_erase(struct mtd_info *m
+@@ -231,13 +233,60 @@ static int part_erase(struct mtd_info *m
  	struct mtd_part *part = PART(mtd);
  	int ret;
  
@@ -70,7 +70,7 @@
  	return ret;
  }
  
-@@ -246,7 +295,25 @@ void mtd_erase_callback(struct erase_inf
+@@ -245,7 +294,25 @@ void mtd_erase_callback(struct erase_inf
  {
  	if (instr->mtd->_erase == part_erase) {
  		struct mtd_part *part = PART(instr->mtd);
@@ -96,7 +96,7 @@
  		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
  			instr->fail_addr -= part->offset;
  		instr->addr -= part->offset;
-@@ -504,18 +571,24 @@ static struct mtd_part *allocate_partiti
+@@ -503,18 +570,24 @@ static struct mtd_part *allocate_partiti
  	if ((slave->mtd.flags & MTD_WRITEABLE) &&
  	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
  		/* Doesn't start on a boundary of major erase size */
diff --git a/target/linux/generic/patches-3.10/412-mtd-partial_eraseblock_unlock.patch b/target/linux/generic/patches-3.10/412-mtd-partial_eraseblock_unlock.patch
index 87c8257fe11..134f65715e9 100644
--- a/target/linux/generic/patches-3.10/412-mtd-partial_eraseblock_unlock.patch
+++ b/target/linux/generic/patches-3.10/412-mtd-partial_eraseblock_unlock.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -332,7 +332,14 @@ static int part_lock(struct mtd_info *mt
+@@ -331,7 +331,14 @@ static int part_lock(struct mtd_info *mt
  static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
  {
  	struct mtd_part *part = PART(mtd);
diff --git a/target/linux/generic/patches-3.10/480-mtd-set-rootfs-to-be-root-dev.patch b/target/linux/generic/patches-3.10/480-mtd-set-rootfs-to-be-root-dev.patch
new file mode 100644
index 00000000000..58c4a8ae3f2
--- /dev/null
+++ b/target/linux/generic/patches-3.10/480-mtd-set-rootfs-to-be-root-dev.patch
@@ -0,0 +1,26 @@
+--- a/drivers/mtd/mtdcore.c
++++ b/drivers/mtd/mtdcore.c
+@@ -37,6 +37,7 @@
+ #include <linux/backing-dev.h>
+ #include <linux/gfp.h>
+ #include <linux/slab.h>
++#include <linux/root_dev.h>
+ 
+ #include <linux/mtd/mtd.h>
+ #include <linux/mtd/partitions.h>
+@@ -408,6 +409,15 @@ int add_mtd_device(struct mtd_info *mtd)
+ 	   of this try_ nonsense, and no bitching about it
+ 	   either. :) */
+ 	__module_get(THIS_MODULE);
++
++	if (!strcmp(mtd->name, "rootfs") &&
++	    config_enabled(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
++	    ROOT_DEV == 0) {
++		pr_notice("mtd: device %d (%s) set to be root filesystem\n",
++			  mtd->index, mtd->name);
++		ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
++	}
++
+ 	return 0;
+ 
+ fail_added:
diff --git a/target/linux/generic/patches-3.12/400-mtd-add-rootfs-split-support.patch b/target/linux/generic/patches-3.12/400-mtd-add-rootfs-split-support.patch
index 215aef14deb..ce91d7ba5e3 100644
--- a/target/linux/generic/patches-3.12/400-mtd-add-rootfs-split-support.patch
+++ b/target/linux/generic/patches-3.12/400-mtd-add-rootfs-split-support.patch
@@ -35,16 +35,15 @@
  	depends on m
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -29,6 +29,8 @@
+@@ -29,6 +29,7 @@
  #include <linux/kmod.h>
  #include <linux/mtd/mtd.h>
  #include <linux/mtd/partitions.h>
-+#include <linux/root_dev.h>
 +#include <linux/magic.h>
  #include <linux/err.h>
  
  #include "mtdcore.h"
-@@ -45,13 +47,14 @@ struct mtd_part {
+@@ -45,13 +46,14 @@ struct mtd_part {
  	struct list_head list;
  };
  
@@ -60,7 +59,7 @@
  /*
   * MTD methods which simply translate the effective address and pass through
   * to the _real_ device.
-@@ -534,8 +537,10 @@ out_register:
+@@ -534,8 +536,10 @@ out_register:
  	return slave;
  }
  
@@ -73,7 +72,7 @@
  {
  	struct mtd_partition part;
  	struct mtd_part *p, *new;
-@@ -567,21 +572,24 @@ int mtd_add_partition(struct mtd_info *m
+@@ -567,21 +571,24 @@ int mtd_add_partition(struct mtd_info *m
  	end = offset + length;
  
  	mutex_lock(&mtd_partitions_mutex);
@@ -108,7 +107,7 @@
  
  	return ret;
  err_inv:
-@@ -591,6 +599,12 @@ err_inv:
+@@ -591,6 +598,12 @@ err_inv:
  }
  EXPORT_SYMBOL_GPL(mtd_add_partition);
  
@@ -121,7 +120,7 @@
  int mtd_del_partition(struct mtd_info *master, int partno)
  {
  	struct mtd_part *slave, *next;
-@@ -614,6 +628,151 @@ int mtd_del_partition(struct mtd_info *m
+@@ -614,6 +627,144 @@ int mtd_del_partition(struct mtd_info *m
  }
  EXPORT_SYMBOL_GPL(mtd_del_partition);
  
@@ -252,13 +251,6 @@
 +	if (!strcmp(part->mtd.name, "rootfs")) {
 +		rootfs_found = 1;
 +
-+		if (config_enabled(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
-+		    ROOT_DEV == 0) {
-+			printk(KERN_NOTICE "mtd: partition \"rootfs\" "
-+				"set to be root filesystem\n");
-+			ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, part->mtd.index);
-+		}
-+
 +		if (config_enabled(CONFIG_MTD_ROOTFS_SPLIT))
 +			split_rootfs_data(master, part);
 +	}
@@ -273,7 +265,7 @@
  /*
   * This function, given a master MTD object and a partition table, creates
   * and registers slave MTD objects which are bound to the master according to
-@@ -643,6 +802,7 @@ int add_mtd_partitions(struct mtd_info *
+@@ -643,6 +794,7 @@ int add_mtd_partitions(struct mtd_info *
  		mutex_unlock(&mtd_partitions_mutex);
  
  		add_mtd_device(&slave->mtd);
diff --git a/target/linux/generic/patches-3.12/401-mtd-add-support-for-different-partition-parser-types.patch b/target/linux/generic/patches-3.12/401-mtd-add-support-for-different-partition-parser-types.patch
index 8d7bcdeee60..52b87f56cc9 100644
--- a/target/linux/generic/patches-3.12/401-mtd-add-support-for-different-partition-parser-types.patch
+++ b/target/linux/generic/patches-3.12/401-mtd-add-support-for-different-partition-parser-types.patch
@@ -11,7 +11,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
 
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -832,6 +832,30 @@ static struct mtd_part_parser *get_parti
+@@ -824,6 +824,30 @@ static struct mtd_part_parser *get_parti
  
  #define put_partition_parser(p) do { module_put((p)->owner); } while (0)
  
@@ -42,7 +42,7 @@ Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
  int register_mtd_parser(struct mtd_part_parser *p)
  {
  	spin_lock(&part_parser_lock);
-@@ -908,6 +932,38 @@ int parse_mtd_partitions(struct mtd_info
+@@ -900,6 +924,38 @@ int parse_mtd_partitions(struct mtd_info
  	return ret;
  }
  
diff --git a/target/linux/generic/patches-3.12/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch b/target/linux/generic/patches-3.12/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch
index 8d0bda825f4..a614094851c 100644
--- a/target/linux/generic/patches-3.12/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch
+++ b/target/linux/generic/patches-3.12/402-mtd-use-typed-mtd-parsers-for-rootfs-and-firmware-split.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -628,6 +628,37 @@ int mtd_del_partition(struct mtd_info *m
+@@ -627,6 +627,37 @@ int mtd_del_partition(struct mtd_info *m
  }
  EXPORT_SYMBOL_GPL(mtd_del_partition);
  
@@ -38,7 +38,7 @@
  static inline unsigned long
  mtd_pad_erasesize(struct mtd_info *mtd, int offset, int len)
  {
-@@ -687,6 +718,10 @@ static void split_rootfs_data(struct mtd
+@@ -686,6 +717,10 @@ static void split_rootfs_data(struct mtd
  	unsigned int split_size;
  	int ret;
  
@@ -49,7 +49,7 @@
  	ret = split_squashfs(master, part->offset, &split_offset);
  	if (ret)
  		return;
-@@ -736,6 +771,12 @@ static void split_uimage(struct mtd_info
+@@ -735,6 +770,12 @@ static void split_uimage(struct mtd_info
  
  static void split_firmware(struct mtd_info *master, struct mtd_part *part)
  {
diff --git a/target/linux/generic/patches-3.12/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch b/target/linux/generic/patches-3.12/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch
index 1ebeca64d1b..a54b97b07c3 100644
--- a/target/linux/generic/patches-3.12/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch
+++ b/target/linux/generic/patches-3.12/404-mtd-use-mtd_get_squashfs_len-in-split_squasfh.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -34,6 +34,7 @@
+@@ -33,6 +33,7 @@
  #include <linux/err.h>
  
  #include "mtdcore.h"
@@ -8,7 +8,7 @@
  
  /* Our partition linked list */
  static LIST_HEAD(mtd_partitions);
-@@ -670,43 +671,16 @@ mtd_pad_erasesize(struct mtd_info *mtd,
+@@ -669,43 +670,16 @@ mtd_pad_erasesize(struct mtd_info *mtd,
  	return len;
  }
  
diff --git a/target/linux/generic/patches-3.12/405-mtd-add-more-helper-functions.patch b/target/linux/generic/patches-3.12/405-mtd-add-more-helper-functions.patch
index c2578c30036..a32aad4f70f 100644
--- a/target/linux/generic/patches-3.12/405-mtd-add-more-helper-functions.patch
+++ b/target/linux/generic/patches-3.12/405-mtd-add-more-helper-functions.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -435,14 +435,12 @@ static struct mtd_part *allocate_partiti
+@@ -434,14 +434,12 @@ static struct mtd_part *allocate_partiti
  	if (slave->offset == MTDPART_OFS_APPEND)
  		slave->offset = cur_offset;
  	if (slave->offset == MTDPART_OFS_NXTBLK) {
@@ -18,7 +18,7 @@
  	}
  	if (slave->offset == MTDPART_OFS_RETAIN) {
  		slave->offset = cur_offset;
-@@ -996,6 +994,24 @@ int mtd_is_partition(const struct mtd_in
+@@ -988,6 +986,24 @@ int mtd_is_partition(const struct mtd_in
  }
  EXPORT_SYMBOL_GPL(mtd_is_partition);
  
diff --git a/target/linux/generic/patches-3.12/411-mtd-partial_eraseblock_write.patch b/target/linux/generic/patches-3.12/411-mtd-partial_eraseblock_write.patch
index 7ecb3312c26..523dd4e3756 100644
--- a/target/linux/generic/patches-3.12/411-mtd-partial_eraseblock_write.patch
+++ b/target/linux/generic/patches-3.12/411-mtd-partial_eraseblock_write.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -36,6 +36,8 @@
+@@ -35,6 +35,8 @@
  #include "mtdcore.h"
  #include "mtdsplit.h"
  
@@ -9,7 +9,7 @@
  /* Our partition linked list */
  static LIST_HEAD(mtd_partitions);
  static DEFINE_MUTEX(mtd_partitions_mutex);
-@@ -232,13 +234,60 @@ static int part_erase(struct mtd_info *m
+@@ -231,13 +233,60 @@ static int part_erase(struct mtd_info *m
  	struct mtd_part *part = PART(mtd);
  	int ret;
  
@@ -70,7 +70,7 @@
  	return ret;
  }
  
-@@ -246,7 +295,25 @@ void mtd_erase_callback(struct erase_inf
+@@ -245,7 +294,25 @@ void mtd_erase_callback(struct erase_inf
  {
  	if (instr->mtd->_erase == part_erase) {
  		struct mtd_part *part = PART(instr->mtd);
@@ -96,7 +96,7 @@
  		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
  			instr->fail_addr -= part->offset;
  		instr->addr -= part->offset;
-@@ -504,18 +571,24 @@ static struct mtd_part *allocate_partiti
+@@ -503,18 +570,24 @@ static struct mtd_part *allocate_partiti
  	if ((slave->mtd.flags & MTD_WRITEABLE) &&
  	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
  		/* Doesn't start on a boundary of major erase size */
diff --git a/target/linux/generic/patches-3.12/412-mtd-partial_eraseblock_unlock.patch b/target/linux/generic/patches-3.12/412-mtd-partial_eraseblock_unlock.patch
index 87c8257fe11..134f65715e9 100644
--- a/target/linux/generic/patches-3.12/412-mtd-partial_eraseblock_unlock.patch
+++ b/target/linux/generic/patches-3.12/412-mtd-partial_eraseblock_unlock.patch
@@ -1,6 +1,6 @@
 --- a/drivers/mtd/mtdpart.c
 +++ b/drivers/mtd/mtdpart.c
-@@ -332,7 +332,14 @@ static int part_lock(struct mtd_info *mt
+@@ -331,7 +331,14 @@ static int part_lock(struct mtd_info *mt
  static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
  {
  	struct mtd_part *part = PART(mtd);
diff --git a/target/linux/generic/patches-3.12/480-mtd-set-rootfs-to-be-root-dev.patch b/target/linux/generic/patches-3.12/480-mtd-set-rootfs-to-be-root-dev.patch
new file mode 100644
index 00000000000..7ef677835ed
--- /dev/null
+++ b/target/linux/generic/patches-3.12/480-mtd-set-rootfs-to-be-root-dev.patch
@@ -0,0 +1,26 @@
+--- a/drivers/mtd/mtdcore.c
++++ b/drivers/mtd/mtdcore.c
+@@ -37,6 +37,7 @@
+ #include <linux/backing-dev.h>
+ #include <linux/gfp.h>
+ #include <linux/slab.h>
++#include <linux/root_dev.h>
+ 
+ #include <linux/mtd/mtd.h>
+ #include <linux/mtd/partitions.h>
+@@ -419,6 +420,15 @@ int add_mtd_device(struct mtd_info *mtd)
+ 	   of this try_ nonsense, and no bitching about it
+ 	   either. :) */
+ 	__module_get(THIS_MODULE);
++
++	if (!strcmp(mtd->name, "rootfs") &&
++	    config_enabled(CONFIG_MTD_ROOTFS_ROOT_DEV) &&
++	    ROOT_DEV == 0) {
++		pr_notice("mtd: device %d (%s) set to be root filesystem\n",
++			  mtd->index, mtd->name);
++		ROOT_DEV = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
++	}
++
+ 	return 0;
+ 
+ fail_added: