core/init: make boot message configurable

It can be desirable to not have the boot message printed each time
(e.g. logs are transferred over a wireless link on battery) while
still retaining the ability to receive INFO level logs.

This adds the option to disable the boot-up message (and also to customize
it if that is desireable).

core/include/kernel_init.h

@@ -25,6 +25,27 @@
 extern "C" {
 #endif
 
+/**
+ * @defgroup core_init_config Core initialization compile configuration
+ * @ingroup config
+ * @{
+ */
+#ifdef DOXYGEN
+
+/**
+ * @brief Enable this to disable printing a message on bootup.
+ */
+#define CONFIG_SKIP_BOOT_MSG
+
+/**
+ * @brief The message printed by RIOT before calling the main() function, when
+ *        @ref CONFIG_SKIP_BOOT_MSG is not set.
+ */
+#define CONFIG_BOOT_MSG_STRING
+
+#endif /* DOXYGEN */
+/** @} */
+
 /**
  * @brief   Initializes scheduler and creates main and idle task
  */

core/init.c

@@ -36,6 +36,10 @@
 #include <auto_init.h>
 #endif
 
+#ifndef CONFIG_BOOT_MSG_STRING
+#define CONFIG_BOOT_MSG_STRING "main(): This is RIOT! (Version: " RIOT_VERSION ")"
+#endif
+
 extern int main(void);
 
 static void *main_trampoline(void *arg)
@@ -46,7 +50,9 @@ static void *main_trampoline(void *arg)
     auto_init();
 #endif
 
-    LOG_INFO("main(): This is RIOT! (Version: " RIOT_VERSION ")\n");
+    if (!IS_ACTIVE(CONFIG_SKIP_BOOT_MSG)) {
+        LOG_INFO(CONFIG_BOOT_MSG_STRING "\n");
+    }
 
     main();