diff --git a/top.tcl b/top.tcl
new file mode 100644
index 0000000..a6d083e
--- /dev/null
+++ b/top.tcl
@@ -0,0 +1,12 @@
+yosys -import
+read_verilog -D$::env(IC) -noautowire -sv top.sv
+puts "device is $::env(IC)" ; 
+
+#yosys proc
+procs
+# the above are the same, see: http://www.clifford.at/yosys/cmd_tcl.html
+
+opt -full
+alumacc
+share -aggressive
+synth_ice40 -abc2 -top top -blif top.blif