diff --git a/m1/tools/xse-sane-init64 b/m1/tools/xse-sane-init64
new file mode 100644
index 0000000..478e590
--- /dev/null
+++ b/m1/tools/xse-sane-init64
@@ -0,0 +1,25 @@
+#!/bin/sh
+#
+# Source this in .bash_profile, before running build_bitstream.sh, etc.
+#
+# The setup process in /opt/Xilinx/13.3/ISE_DS/settings64.sh
+# is an ode to bloat. Below are the things we actually need from it.
+#
+
+x=/opt/Xilinx/13.3/ISE_DS
+
+PATH=$PATH:$x/common/bin/lin64
+PATH=$PATH:$x/ISE/bin/lin64
+PATH=$PATH:$x/ISE/sysgen/util
+
+if [ "$LD_LIBRARY_PATH" ]; then
+	LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$x/common/lib/lin64
+else
+	LD_LIBRARY_PATH=$x/common/lib/lin64
+fi
+LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$x/ISE/lib/lin64
+
+XILINX=$x/ISE
+
+export LD_LIBRARY_PATH XILINX
+x=