storage: flash_map: add flash_area_copy()

add flash_area_copy() function based on
flash_copy().

Signed-off-by: Fin Maaß <f.maass@vogl-electronic.com>

include/zephyr/storage/flash_map.h

@@ -188,6 +188,28 @@ int flash_area_read(const struct flash_area *fa, off_t off, void *dst,
 int flash_area_write(const struct flash_area *fa, off_t off, const void *src,
 		     size_t len);
 
+/**
+ * @brief Copy flash memory from one flash area to another.
+ *
+ * Copy data to flash area. Area boundaries are asserted before copy
+ * request.
+ *
+ * For more information, see flash_copy().
+ *
+ * @param[in]  src_fa  Source Flash area
+ * @param[in]  src_off Offset relative from beginning of source flash area.
+ * @param[in]  dst_fa  Destination Flash area
+ * @param[in]  dst_off Offset relative from beginning of destination flash area.
+ * @param[in]  len Number of bytes to copy, in bytes.
+ * @param[out] buf Pointer to a buffer of size @a buf_size.
+ * @param[in]  buf_size Size of the buffer pointed to by @a buf.
+ *
+ * @return  0 on success, negative errno code on fail.
+ */
+int flash_area_copy(const struct flash_area *src_fa, off_t src_off,
+		    const struct flash_area *dst_fa, off_t dst_off,
+		    off_t len, uint8_t *buf, size_t buf_size);
+
 /**
  * @brief Erase flash area
  *

subsys/storage/flash_map/flash_map.c

@@ -82,6 +82,20 @@ int flash_area_erase(const struct flash_area *fa, off_t off, size_t len)
 	return flash_erase(fa->fa_dev, fa->fa_off + off, len);
 }
 
+int flash_area_copy(const struct flash_area *src_fa, off_t src_off,
+		    const struct flash_area *dst_fa, off_t dst_off,
+		    off_t len, uint8_t *buf, size_t buf_size)
+{
+	if (!(is_in_flash_area_bounds(src_fa, src_off, len) &&
+	      is_in_flash_area_bounds(dst_fa, dst_off, len))) {
+		return -EINVAL;
+	}
+
+	return flash_copy(src_fa->fa_dev, src_fa->fa_off + src_off,
+			  dst_fa->fa_dev, dst_fa->fa_off + dst_off, len, buf,
+			  buf_size);
+}
+
 int flash_area_flatten(const struct flash_area *fa, off_t off, size_t len)
 {
 	if (!is_in_flash_area_bounds(fa, off, len)) {