usage message

diff --git a/hostside/main.c b/hostside/main.c
index a45403e9e60416e32314797a0ba05e2ae78304c1..186bc1c708653600f2f324f7b24e7d69ec40cadf 100644 (file)
--- a/hostside/main.c
+++ b/hostside/main.c
@@ -1,4 +1,11 @@
-/**/
+/*
+ * simple test harness for now
+ * asserts on usage errors
+ * usage:
+ *    ./hostside /dev/ttySn DATA               nmra
+ *    ./hostside /dev/ttySn DATA command       already encoded - raw transmit
+ * DATA is an even number of hex digits in a single arg
+ */
 
 #include <stdio.h>
 #include <string.h>