support writing new configs as .uf2 files via the TUI

`edit-config --filename foo.uf2` can now create standalone config UF2
files. still working on reading UF2s, or maybe what edit-config needs is
a "Save As..." in order to read from a board/config and output it to a
new file, but this is a start

Signed-off-by: Brian S. Stephan <bss@incorporeal.org>

gp2040ce_bintools/builder.py

@@ -214,11 +214,16 @@ def write_new_config_to_filename(config: Message, filename: str, inject: bool =
         with open(filename, 'rb') as file:
             existing_binary = file.read()
         binary = replace_config_in_binary(bytearray(existing_binary), config_binary)
+        with open(filename, 'wb') as file:
+            file.write(binary)
     else:
         binary = serialize_config_with_footer(config)
-
-    with open(filename, 'wb') as file:
-        file.write(binary)
+        with open(filename, 'wb') as file:
+            if filename[-4:] == '.uf2':
+                file.write(convert_binary_to_uf2(pad_config_to_storage_size(binary),
+                                                 start=USER_CONFIG_BINARY_LOCATION))
+            else:
+                file.write(binary)
 
 
 def write_new_config_to_usb(config: Message, endpoint_out: object, endpoint_in: object):

gp2040ce_bintools/gui.py

@@ -409,8 +409,9 @@ def edit_config():
     group = parser.add_mutually_exclusive_group(required=True)
     group.add_argument('--usb', action='store_true', help="retrieve the config from a RP2040 board connected over USB "
                                                           "and in BOOTSEL mode")
-    group.add_argument('--filename', help=".bin file of a GP2040-CE board's config + footer or entire storage section, "
-                                          "or of a GP2040-CE's whole board dump if --whole-board is specified")
+    group.add_argument('--filename', help=".bin of a GP2040-CE's whole board dump if --whole-board is specified, or a"
+                                          ".bin file of a GP2040-CE board's config + footer or entire storage section; "
+                                          "if creating a new config, it can also be written in .uf2 format")
     args, _ = parser.parse_known_args()
 
     if args.usb:

tests/test_builder.py

@@ -15,7 +15,7 @@ from gp2040ce_bintools.builder import (FirmwareLengthError, combine_firmware_and
                                        concatenate_firmware_and_storage_files, get_gp2040ce_from_usb,
                                        pad_binary_up_to_board_config, pad_binary_up_to_user_config,
                                        replace_config_in_binary, write_new_config_to_filename, write_new_config_to_usb)
-from gp2040ce_bintools.storage import (get_board_storage_section, get_config, get_config_footer,
+from gp2040ce_bintools.storage import (STORAGE_SIZE, get_board_storage_section, get_config, get_config_footer,
                                        get_user_storage_section, serialize_config_with_footer)
 
 HERE = os.path.dirname(os.path.abspath(__file__))
@@ -272,6 +272,23 @@ def test_write_new_config_to_config_bin(firmware_binary, tmp_path):
     assert len(config_dump) == config_size + 12
 
 
+@with_pb2s
+def test_write_new_config_to_config_uf2(firmware_binary, tmp_path):
+    """Test that the config can be written to a file."""
+    tmp_file = os.path.join(tmp_path, 'config.uf2')
+    config_pb2 = get_config_pb2()
+    config = config_pb2.Config()
+    config.boardVersion = 'v0.7.5-COOL'
+    write_new_config_to_filename(config, tmp_file)
+
+    # read new file
+    with open(tmp_file, 'rb') as file:
+        config_dump = file.read()
+    # the current implementation of UF2 writing does it in 256 blocks, so each 256 byte block of
+    # binary is 512 bytes in the UF2
+    assert len(config_dump) == STORAGE_SIZE * 2
+
+
 @with_pb2s
 def test_write_new_config_to_usb(config_binary):
     """Test that the config can be written to USB at the proper alignment."""