scripts: Adding license header checking.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>
diff --git a/Makefile b/Makefile
index 12cbbd4..648dea6 100644
--- a/Makefile
+++ b/Makefile
@@ -30,6 +30,32 @@
 		> README.rst
 
 
+COPYRIGHT_HOLDER := SkyWater PDK Authors
+FIND := find . -path ./env -prune -o -path ./.git -prune -o
+ADDLICENSE := addlicense -f ./docs/license_header.txt
+fix-licenses:
+	@# Makefiles
+	@$(FIND) -type f -name Makefile -exec $(ADDLICENSE) $(ADDLICENSE_EXTRA) -v \{\} \+
+	@$(FIND) -type f -name \*.mk -exec $(ADDLICENSE) $(ADDLICENSE_EXTRA) -v \{\} \+
+	@# Scripting files
+	@$(FIND) -type f -name \*.sh -exec $(ADDLICENSE) $(ADDLICENSE_EXTRA) -v \{\} \+
+	@$(FIND) -type f -name \*.py -exec $(ADDLICENSE) $(ADDLICENSE_EXTRA) -v \{\} \+
+	@# Configuration files
+	@$(FIND) -type f -name \*.yml  -exec $(ADDLICENSE) $(ADDLICENSE_EXTRA) -v \{\} \+
+	@# Actual PDK files
+	@$(FIND) -type f -name \*.v  -exec $(ADDLICENSE) $(ADDLICENSE_EXTRA) -v \{\} \+
+
+.PHONY: fix-licenses
+
+check-licenses:
+	@make --no-print-directory ADDLICENSE_EXTRA=--check fix-licenses
+
+.PHONY: check-licenses
+
+
+check: check-licenses
+	@true
+
 all: README.rst
 	@true
 
diff --git a/docs/license_header.txt b/docs/license_header.txt
new file mode 100644
index 0000000..b89bc66
--- /dev/null
+++ b/docs/license_header.txt
@@ -0,0 +1,15 @@
+Copyright 2020 SkyWater PDK Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+SPDX-License-Identifier: Apache-2.0
diff --git a/environment.yml b/environment.yml
index 7ef974e..69f2ca1 100644
--- a/environment.yml
+++ b/environment.yml
@@ -1,3 +1,18 @@
+# Copyright 2020 SkyWater PDK Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# SPDX-License-Identifier: Apache-2.0
 name: skywater-pdk-scripts
 dependencies:
 - python