Make the tar file more deterministic.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>
diff --git a/open_pdks/run.sh b/open_pdks/run.sh
index 36fb18a..8848d18 100755
--- a/open_pdks/run.sh
+++ b/open_pdks/run.sh
@@ -80,7 +80,21 @@
 	whoami
 	ls -l out/pdk-all
 	cd out/pdk-all
-	sudo tar -cvf --xz $TOP_DIR/out/pdk-SKY130A.tar.xz .
+	# Try to create a deterministic tar file
+	# https://reproducible-builds.org/docs/archives/
+	sudo tar \
+		--create \
+		--xz \
+		--verbose \
+		\
+		--mtime='2020-05-07 00:00Z' \
+		--sort=name \
+		--owner=0 \
+		--group=0 \
+		--numeric-owner \
+		--pax-option=exthdr.name=%d/PaxHeaders/%f,delete=atime,delete=ctime \
+		\
+		--file $TOP_DIR/out/pdk-SKY130A.tar.xz .
 )
 sudo chown $UID $TOP_DIR/out/*.tar.xz
 du -h $TOP_DIR/out/*.tar.xz