- return spi_flash_read(dfu->data.sf.dev, offset, *len, buf);
+ return spi_flash_read(dfu->data.sf.dev, dfu->data.sf.start + offset,
+ *len, buf);
+}
+
+static u64 find_sector(struct dfu_entity *dfu, u64 start, u64 offset)
+{
+ return (lldiv((start + offset), dfu->data.sf.dev->sector_size)) *
+ dfu->data.sf.dev->sector_size;