tockloader: fix address-truthiness bugs around a valid 0x0

tockloader/app_padding.py

@@ -73,7 +73,7 @@ def get_binary(self, address=None):
         tbfh_binary = self.tbfh.get_binary()
         # Calculate the padding length.
         padding_binary_size = self.get_size() - len(tbfh_binary)
-        return tbfh_binary + b"\xFF" * padding_binary_size
+        return tbfh_binary + b"\xff" * padding_binary_size
 
     def info(self, verbose=False):
         """

tockloader/board_interface.py

@@ -563,7 +563,7 @@ def get_apps_start_address(self):
         """
         Return the address in flash where apps start.
         """
-        if hasattr(self, "app_address") and self.app_address:
+        if hasattr(self, "app_address") and self.app_address is not None:
             return self.app_address
         else:
             attributes = self.get_all_attributes()

tockloader/flash_file.py

@@ -120,7 +120,7 @@ def translate_address(self, address):
         return address - flash_address
 
     def get_flash_address(self):
-        if hasattr(self, "flash_address") and self.flash_address:
+        if hasattr(self, "flash_address") and self.flash_address is not None:
             return self.flash_address
         return None
 
@@ -216,9 +216,9 @@ def set_local_board(
     local_board = {"board": board, "filepath": filepath}
     if arch:
         local_board["arch"] = arch
-    if app_address:
+    if app_address is not None:
         local_board["app_address"] = app_address
-    if flash_address:
+    if flash_address is not None:
         local_board["flash_address"] = flash_address
     if flush_command:
         local_board["flush_command"] = flush_command

tockloader/main.py

@@ -467,9 +467,9 @@ def command_local_board_set(args):
     logging.status(f"Setting the default local board to '{board_name}'")
     if args.arch:
         logging.status(f"  Using arch {args.arch}")
-    if args.app_address:
+    if args.app_address is not None:
         logging.status(f"  Using app_address {args.app_address:#02x}")
-    if args.flash_address:
+    if args.flash_address is not None:
         logging.status(f"  Using flash_address {args.flash_address:#02x}")
     if args.flush_command:
         logging.status(f'  Using flush_command "{args.flush_command}"')

tockloader/tockloader.py

@@ -1098,20 +1098,20 @@ def _get_apps_start_address(self):
         # have a good way to mark it as unset since
         # app_settings['start_address'] is set by default.
         cached = getattr(self, "apps_start_address", None)
-        if cached:
+        if cached is not None:
             return cached
 
         # Highest priority is the command line argument. If the user specifies
         # that, we use that unconditionally.
         cmdline_app_address = getattr(self.args, "app_address", None)
-        if cmdline_app_address:
+        if cmdline_app_address is not None:
             self.apps_start_address = cmdline_app_address
             return cmdline_app_address
 
         # Next we check if the attached board can tell us.
         if self.channel:
             channel_apps_start_address = self.channel.get_apps_start_address()
-            if channel_apps_start_address:
+            if channel_apps_start_address is not None:
                 self.apps_start_address = channel_apps_start_address
                 return channel_apps_start_address
 
@@ -1127,7 +1127,7 @@ def _get_flash_start_address(self):
         # Check if the attached board can tell us.
         if self.channel:
             channel_flash_address = self.channel.get_flash_address()
-            if channel_flash_address:
+            if channel_flash_address is not None:
                 return channel_flash_address
 
         # In the default case flash starts at address 0.
@@ -1143,7 +1143,7 @@ def _get_memory_start_address(self):
         # app RAM address often, so we don't want to have to query the board for
         # it each time.
         cached = getattr(self, "app_ram_address", None)
-        if cached:
+        if cached is not None:
             return cached
 
         # Next we check for kernel attributes.