Correct auto-sizing last region of bl

tools/config/__init__.py

@@ -566,6 +566,7 @@ def regions(self):
 
     def _generate_bootloader_build(self, rom_start, rom_size):
         start = rom_start
+        rom_end = rom_start + rom_size
         if self.target.bootloader_img:
             if isabs(self.target.bootloader_img):
                 filename = self.target.bootloader_img
@@ -588,10 +589,10 @@ def _generate_bootloader_build(self, rom_start, rom_size):
             new_size = Config._align_floor(start + new_size, self.sectors) - start
             yield Region("application", start, new_size, True, None)
             start += new_size
-            yield Region("post_application", start, rom_size - start,
+            yield Region("post_application", start, rom_end - start,
                          False, None)
         else:
-            yield Region("application", start, rom_size - start,
+            yield Region("application", start, rom_end - start,
                          True, None)
         if start > rom_start + rom_size:
             raise ConfigException("Not enough memory on device to fit all "

tools/test/config/config_test.py

@@ -174,3 +174,25 @@ def test_init_override_app_config(target):
 
         mock_json_file_to_dict.assert_any_call(app_config)
         assert config.app_config_data == mock_return
+
+@pytest.mark.parametrize("target", ["K64F", "UBLOX_EVK_ODIN_W2"])
+@pytest.mark.parametrize("overrides", [
+    {},
+    {"restrict_size": "0x200"},
+    {"mbed_app_start": "0x200"}
+])
+def test_basic_regions(target, overrides):
+    """
+    Test that the region lists are sane with various configurations
+    """
+    set_targets_json_location()
+    config = Config(target)
+    for o, v in overrides.items():
+        setattr(config.target, o, v)
+    try:
+        if config.has_regions:
+            regions = list(config.regions)
+            for r in regions:
+                assert r.size >= 0
+    except ConfigException:
+        pass