diff --git a/plat/cpm/libsys/make_bdos_call.sh b/plat/cpm/libsys/make_bdos_call.sh
new file mode 100755
index 000000000..949523007
--- /dev/null
+++ b/plat/cpm/libsys/make_bdos_call.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+cat <<EOF
+#
+#include "asm.h"
+.define _$2
+_$2:
+    mvi a, $1
+    jmp call_bdos
+EOF
+