erase the whole flash at start of dfu

embassy-boot/boot/src/firmware_updater/blocking.rs

@@ -187,12 +187,12 @@ impl<'d, DFU: NorFlash, STATE: NorFlash> BlockingFirmwareUpdater<'d, DFU, STATE>
         //assert!(data.len() >= DFU::ERASE_SIZE);
         self.state.verify_booted()?;
 
-        //self.dfu.erase(offset as u32, (offset + DFU::ERASE_SIZE) as u32)?;
-
-        if self.dfu.write(offset as u32 + 0x00100000, data).is_err() {
-            panic!("range: {:?}", offset..offset+data.len());
+        if offset == 0 {
+            self.dfu.erase(0, self.dfu.capacity() as u32)?;
         }
 
+        self.dfu.write(offset as u32, data)?;
+
         Ok(())
     }