flash: implement a default function for copying data

include/flash.h

@@ -24,6 +24,8 @@ struct flash_dev {
 };
 
 int default_flash_is_erased(struct flash_dev *dev, uint32_t addr);
+size_t default_flash_copy(struct flash_dev *dev, uint32_t dst, uint32_t src,
+	size_t len);
 
 struct flash_dev *flash_probe(void);
 void flash_release(struct flash_dev *dev);

source/core/flash.c

@@ -29,6 +29,32 @@ int default_flash_is_erased(struct flash_dev *dev, uint32_t addr)
 	return 1;
 }
 
+size_t default_flash_copy(struct flash_dev *dev, uint32_t dst, uint32_t src,
+	size_t len)
+{
+	uint8_t data[32];
+	size_t nbytes, ret = 0;
+
+	while (len) {
+		nbytes = min(sizeof data, len);
+
+		if (flash_read(dev, src, data, nbytes) == 0)
+			return -1;
+
+		if (flash_write(dev, dst, data, nbytes) == 0)
+			return -1;
+
+		dst += nbytes;
+		src += nbytes;
+		len -= nbytes;
+		ret += nbytes;
+	}
+
+	return ret;
+}
+
+
+
 void flash_release(struct flash_dev *dev)
 {
 	if (!dev)