Added const qualfier to keep cc65 happy
diff --git a/contiki/ek/log.h b/contiki/ek/log.h
index f449ef1..3d13b0b 100644
--- a/contiki/ek/log.h
+++ b/contiki/ek/log.h
@@ -4,7 +4,7 @@
 #include "log-conf.h"
 
 #if LOG_CONF_ENABLED
-void log_message(char *part1, char *part2);
+void log_message(const char *part1, const char *part2);
 #else /* LOG_CONF_ENABLED */
 #define log_message(p1, p2)
 #endif /* LOG_CONF_ENABLED */