Add an MTD driver to wrap another MTD driver and makes is sector size look like 512 bytes

drivers/mtd/Kconfig

@@ -26,6 +26,27 @@ config MTD_PARTITION
 		managing the sub-region of flash beginning at 'offset' (in blocks)
 		and of size 'nblocks' on the device specified by 'mtd'.
 
+config MTD_SECT512
+	bool "512B sector conversion"
+	default n
+	---help---
+		If enabled, a MTD driver will be created that will convert the
+		sector size of any other MTD driver to a 512 byte "apparent" sector
+		size.  The managed MTD driver in this case must have an erase block
+		size that is greater than 512B and an event multiple of 512B.
+
+if MTD_SECT512
+
+config MTD_SECT512_ERASED_STATE
+	hex "Erased state of the FLASH"
+	default 0xff
+
+config MTD_SECT512_READONLY
+	bool "512B read-only"
+	default n
+
+endif # MTD_SECT512
+
 config MTD_PARTITION_NAMES
 	bool "Support MTD partition naming"
 	depends on FS_PROCFS

drivers/mtd/Make.defs

@@ -45,6 +45,10 @@ ifeq ($(CONFIG_MTD_PARTITION),y)
 CSRCS += mtd_partition.c
 endif
 
+ifeq ($(CONFIG_MTD_SECT512),y)
+CSRCS += sector512.c
+endif
+
 ifeq ($(CONFIG_MTD_NAND),y)
 CSRCS += mtd_nand.c mtd_onfi.c mtd_nandscheme.c mtd_nandmodel.c mtd_modeltab.c
 ifeq ($(CONFIG_MTD_NAND_SWECC),y)

include/nuttx/mtd/mtd.h

@@ -266,6 +266,24 @@ int smart_initialize(int minor, FAR struct mtd_dev_s *mtd,
  * functions (such as a block or character driver front end).
  */
 
+/************************************************************************************
+ * Name: s512_initialize
+ *
+ * Description:
+ *   Create an initialized MTD device instance.  This MTD driver contains another
+ *   MTD driver and converts a larger sector size to a standard 512 byte sector
+ *   size.
+ *
+ *   MTD devices are not registered in the file system, but are created as instances
+ *   that can be bound to other functions (such as a block or character driver front
+ *   end).
+ *
+ ************************************************************************************/
+
+#ifdef CONFIG_MTD_SECT512
+FAR struct mtd_dev_s *s512_initialize(FAR struct mtd_dev_s *mtd);
+#endif
+
 /****************************************************************************
  * Name: at45db_initialize
  *