Add licence headers to all source files

The licence header explains that the given file is part of this
project, and expresses the copyright information and the licence
the file is licensed under using SPDX headers to keep the header
short.

While we have a repo-global LICENSE file, having licence text
directly in a source file makes it very clear for anyone who
copies the file what the licence/copyright is.

Author: wnienhaus

.github/workflows/publish.yml

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 name: Publish Python Package
 
 on:

.github/workflows/run_tests.yaml

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 name: CI
 
 on: [push, pull_request]

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright 2018-2022 by the micropython-esp32-ulp authors, see AUTHORS file
+Copyright 2018-2023 by the micropython-esp32-ulp authors, see AUTHORS file
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

demo.S

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 # comment-only line
 
             .text

demo.sh

@@ -1 +1,8 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 micropython -m esp32_ulp demo.S

esp32_ulp/__init__.py

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 from .util import garbage_collect
 
 from .preprocess import preprocess

esp32_ulp/__main__.py

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 import sys
 from . import assemble_file
 

esp32_ulp/assemble.py

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 """
 ESP32 ULP Co-Processor Assembler
 """

esp32_ulp/definesdb.py

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 import os
 import btree
 from .util import file_exists

esp32_ulp/link.py

@@ -1,3 +1,10 @@
+#
+# This file is part of the micropython-esp32-ulp project,
+# https://github.com/micropython/micropython-esp32-ulp
+#
+# SPDX-FileCopyrightText: 2018-2023, the micropython-esp32-ulp authors, see AUTHORS file.
+# SPDX-License-Identifier: MIT
+
 from uctypes import struct, addressof, LITTLE_ENDIAN, UINT16, UINT32