Added option to check for possible overlapping during write_flash o…

…peration.

If there's a need to flash overlapping data, can be done by running esptool.py write_flash multiple times.

Commits from Pull Request #176

esptool.py

@@ -2148,6 +2148,19 @@ def __call__(self, parser, namespace, values, option_string=None):
             except IndexError:
                 raise argparse.ArgumentError(self,'Must be pairs of an address and the binary filename to write there')
             pairs.append((address, argfile))
+
+        # Sort the addresses and check for overlapping
+        end = 0
+        for address, argfile in sorted(pairs):
+            argfile.seek(0,2)  # seek to end
+            size = argfile.tell()
+            argfile.seek(0)
+            sector_start = address & ~(ESPLoader.FLASH_SECTOR_SIZE - 1)
+            sector_end = ((address + size + ESPLoader.FLASH_SECTOR_SIZE - 1) & ~(ESPLoader.FLASH_SECTOR_SIZE - 1)) - 1
+            if sector_start < end:
+                message = 'Detected overlap at address: 0x%x for file: %s' % (address, argfile.name)
+                raise argparse.ArgumentError(self, message)
+            end = sector_end
         setattr(namespace, self.dest, pairs)
 
 

test/test_esptool.py

@@ -184,6 +184,19 @@ def test_length_not_aligned_4bytes(self):
     def test_length_not_aligned_4bytes_no_compression(self):
         self.run_esptool("write_flash -u 0x0 images/%s" % NODEMCU_FILE)
 
+    def test_write_overlap(self):
+        output = self.run_esptool_error("write_flash 0x0 images/bootloader.bin 0x1000 images/one_kb.bin")
+        self.assertIn("Detected overlap at address: 0x1000 ", output)
+
+    def test_write_sector_overlap(self):
+        # These two 1KB files don't overlap, but they do both touch sector at 0x1000 so should fail
+        output = self.run_esptool_error("write_flash 0xd00 images/one_kb.bin 0x1d00 images/one_kb.bin")
+        self.assertIn("Detected overlap at address: 0x1d00", output)
+
+    def test_write_no_overlap(self):
+        output = self.run_esptool("write_flash 0x0 images/bootloader.bin 0x2000 images/one_kb.bin")
+        self.assertNotIn("Detected overlap at address", output)
+
 class TestFlashSizes(EsptoolTestCase):
 
     def test_high_offset(self):