config: Initialize IO drivers on demand

cpukit/sapi/src/exinit.c

@@ -22,7 +22,6 @@
 #include <rtems/config.h>
 #include <rtems/extensionimpl.h>
 #include <rtems/init.h>
-#include <rtems/ioimpl.h>
 #include <rtems/sysinit.h>
 #include <rtems/score/sysstate.h>
 
@@ -120,18 +119,6 @@ RTEMS_SYSINIT_ITEM(
   RTEMS_SYSINIT_ORDER_MIDDLE
 );
 
-/* Initialize I/O drivers.
- *
- * Driver Manager note:
- * All drivers may not be registered yet. Drivers will dynamically
- * be initialized when registered in level 2,3 and 4.
- */
-RTEMS_SYSINIT_ITEM(
-  _IO_Initialize_all_drivers,
-  RTEMS_SYSINIT_DEVICE_DRIVERS,
-  RTEMS_SYSINIT_ORDER_MIDDLE
-);
-
 void rtems_initialize_executive(void)
 {
   const rtems_sysinit_item *item;

cpukit/sapi/src/iodefault.c

@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup ClassicIO
+ *
+ * @brief This file contains definitions of IO drivers data structures for the
+ * default application configuration.
+ */
+
+/*
+ * Copyright (C) 2020 embedded brains GmbH (http://www.embedded-brains.de)
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <rtems/ioimpl.h>
+
+rtems_driver_address_table _IO_Driver_address_table[ 0 ];
+
+const size_t _IO_Number_of_drivers = 0;