4 files changed, 98 insertions, 5 deletions
diff --git a/tools/build_zephyr.py b/tools/build_zephyr.py
index 1d9e783..5dd9e47 100755
--- a/tools/build_zephyr.py
+++ b/tools/build_zephyr.py
@@ -38,10 +38,7 @@ def main() -> None:
         check=True,
     )
 
-    shutil.copy(
-        build_tree / "zephyr" / args.binary_name,
-        output_dir / args.target_name
-    )
+    shutil.copy(build_tree / "zephyr" / args.binary_name, output_dir / args.target_name)
 
 
 if __name__ == "__main__":
diff --git a/tools/configure_zephyr.py b/tools/configure_zephyr.py
index e709063..f4707c6 100755
--- a/tools/configure_zephyr.py
+++ b/tools/configure_zephyr.py
@@ -43,7 +43,7 @@ def main() -> None:
         command.append(f"-DEXTRA_CONF_FILE={args.extra_config}")
 
     if args.signing_key is not None:
-        command.append(f"-DCONFIG_BOOT_SIGNATURE_KEY_FILE=\"{args.signing_key}\"")
+        command.append(f'-DCONFIG_BOOT_SIGNATURE_KEY_FILE="{args.signing_key}"')
 
     subprocess.run(command, shell=False, check=True)
 
diff --git a/tools/make_factory_image.py b/tools/make_factory_image.py
new file mode 100755
index 0000000..735f657
--- /dev/null
+++ b/tools/make_factory_image.py
@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+
+
+import argparse
+import dataclasses
+import pathlib
+
+
+PADDING_BYTE: bytes = b"\xff"
+
+
+def main() -> None:
+    args = Arguments.from_cli()
+    print(args)
+
+    factory_image: bytes = join(
+        bootloader=args.bootloader.read_bytes(),
+        application=args.application.read_bytes(),
+        offset=args.offset,
+    )
+
+    args.factory_image.write_bytes(factory_image)
+
+
+def join(bootloader: bytes, application: bytes, offset: int) -> bytes:
+    padding = PADDING_BYTE * (offset - len(bootloader))
+
+    return bootloader + padding + application
+
+
+@dataclasses.dataclass
+class Arguments:
+    bootloader: pathlib.Path
+    offset: int
+    application: pathlib.Path
+    factory_image: pathlib.Path
+
+    def __post_init__(self) -> None:
+        assert isinstance(self.bootloader, pathlib.Path)
+
+        assert isinstance(self.offset, int)
+        assert self.offset >= 0
+
+        assert isinstance(self.application, pathlib.Path)
+
+        assert isinstance(self.factory_image, pathlib.Path)
+
+    def __str__(self) -> str:
+        return f"""{__file__} \\
+    --bootloader {self.bootloader} \\
+    --offset 0x{self.offset:X} \\
+    --application {self.application} \\
+    --factory_image {self.factory_image}"""
+
+    @staticmethod
+    def from_cli() -> "Arguments":
+        parser = argparse.ArgumentParser(
+            description="Join bootloader and application firmware to a factory image"
+        )
+
+        parser.add_argument(
+            "-b", "--bootloader", required=True, help="path to bootloader firmware"
+        )
+
+        default_offset = 0x40000
+        parser.add_argument(
+            "-o",
+            "--offset",
+            default=default_offset,
+            help=f"offset in bytes between bootloader and application (default: 0x{default_offset:X})",
+        )
+
+        parser.add_argument(
+            "-a", "--application", required=True, help="path to application firmware"
+        )
+
+        parser.add_argument(
+            "-f",
+            "--factory-image",
+            default=pathlib.Path("factory-image.bin"),
+            help="path to output factory image file",
+        )
+
+        args = parser.parse_args()
+
+        return Arguments(
+            bootloader=pathlib.Path(args.bootloader),
+            offset=int(args.offset),
+            application=pathlib.Path(args.application),
+            factory_image=pathlib.Path(args.factory_image),
+        )
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tools/meson.build b/tools/meson.build
index 85ddbb3..f58c54b 100644
--- a/tools/meson.build
+++ b/tools/meson.build
@@ -1,2 +1,3 @@
 configure_zephyr = meson.current_source_dir() / 'configure_zephyr.py'
 build_zephyr = meson.current_source_dir() / 'build_zephyr.py'
+make_factory_image = meson.current_source_dir() / 'make_factory_image.py'