[PATCH] config: Initialize IO drivers on demand

[Sebastian Huber]

---
 cpukit/Makefile.am                        |  1 +
 cpukit/include/rtems/confdefs/iodrivers.h | 29 ++++++++++++++++++++
 cpukit/sapi/src/exinit.c                  | 13 ---------
 cpukit/sapi/src/iodefault.c               | 45 +++++++++++++++++++++++++++++++
 4 files changed, 75 insertions(+), 13 deletions(-)
 create mode 100644 cpukit/sapi/src/iodefault.c

diff --git a/cpukit/Makefile.am b/cpukit/Makefile.am
index 9ed260addb..298580e20d 100644
--- a/cpukit/Makefile.am
+++ b/cpukit/Makefile.am
@@ -1056,6 +1056,7 @@ librtemscpu_a_SOURCES += sapi/src/getconfigmax.c
 librtemscpu_a_SOURCES += sapi/src/getversionstring.c
 librtemscpu_a_SOURCES += sapi/src/interrtext.c
 librtemscpu_a_SOURCES += sapi/src/io.c
+librtemscpu_a_SOURCES += sapi/src/iodefault.c
 librtemscpu_a_SOURCES += sapi/src/ioclose.c
 librtemscpu_a_SOURCES += sapi/src/iocontrol.c
 librtemscpu_a_SOURCES += sapi/src/ioinitialize.c
diff --git a/cpukit/include/rtems/confdefs/iodrivers.h b/cpukit/include/rtems/confdefs/iodrivers.h
index 1e7b8c4e13..7ebe2ed474 100644
--- a/cpukit/include/rtems/confdefs/iodrivers.h
+++ b/cpukit/include/rtems/confdefs/iodrivers.h
@@ -42,7 +42,19 @@
 
 #ifdef CONFIGURE_INIT
 
+#if defined(CONFIGURE_APPLICATION_EXTRA_DRIVERS) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_ATA_DRIVER) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_FRAME_BUFFER_DRIVER) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_IDE_DRIVER) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_NULL_DRIVER) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_RTC_DRIVER) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_STUB_DRIVER) \
+  || defined(CONFIGURE_APPLICATION_NEEDS_ZERO_DRIVER) \
+  || CONFIGURE_MAXIMUM_DRIVERS > 0
+
 #include <rtems/ioimpl.h>
+#include <rtems/sysinit.h>
 
 #ifdef CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
   #if defined(CONFIGURE_APPLICATION_NEEDS_SIMPLE_CONSOLE_DRIVER) \
@@ -150,6 +162,12 @@ _IO_Driver_address_table[ CONFIGURE_MAXIMUM_DRIVERS ] = {
 const size_t _IO_Number_of_drivers =
   RTEMS_ARRAY_SIZE( _IO_Driver_address_table );
 
+RTEMS_SYSINIT_ITEM(
+  _IO_Initialize_all_drivers,
+  RTEMS_SYSINIT_DEVICE_DRIVERS,
+  RTEMS_SYSINIT_ORDER_MIDDLE
+);
+
 #ifdef CONFIGURE_APPLICATION_NEEDS_ATA_DRIVER
   #ifndef CONFIGURE_ATA_DRIVER_TASK_PRIORITY
     #define CONFIGURE_ATA_DRIVER_TASK_PRIORITY ATA_DRIVER_TASK_DEFAULT_PRIORITY
@@ -163,6 +181,17 @@ const size_t _IO_Number_of_drivers =
 }
 #endif
 
+#endif /* CONFIGURE_APPLICATION_EXTRA_DRIVERS
+  || CONFIGURE_APPLICATION_NEEDS_ATA_DRIVER
+  || CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
+  || CONFIGURE_APPLICATION_NEEDS_FRAME_BUFFER_DRIVER
+  || CONFIGURE_APPLICATION_NEEDS_IDE_DRIVER
+  || CONFIGURE_APPLICATION_NEEDS_NULL_DRIVER
+  || CONFIGURE_APPLICATION_NEEDS_RTC_DRIVER
+  || CONFIGURE_APPLICATION_NEEDS_STUB_DRIVER
+  || CONFIGURE_APPLICATION_NEEDS_ZERO_DRIVER
+  || CONFIGURE_MAXIMUM_DRIVERS */
+
 #endif /* CONFIGURE_INIT */
 
 #endif /* _RTEMS_CONFDEFS_IODRIVERS_H */
diff --git a/cpukit/sapi/src/exinit.c b/cpukit/sapi/src/exinit.c
index 196c9be576..e29b364806 100644
--- a/cpukit/sapi/src/exinit.c
+++ b/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;
diff --git a/cpukit/sapi/src/iodefault.c b/cpukit/sapi/src/iodefault.c
new file mode 100644
index 0000000000..114a419d19
--- /dev/null
+++ b/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;
-- 
2.16.4