arch: qemu-rv: Add qemu_rv_virtio.c

Summary:
- This commit adds qemu_rv_virtio.c

Impact:
- None

Testing
- Tested with rv-virt:netnsh (will be added later)

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

arch/risc-v/src/qemu-rv/Make.defs

@@ -36,3 +36,7 @@ endif
 ifeq ($(CONFIG_MM_PGALLOC),y)
 CHIP_CSRCS += qemu_rv_pgalloc.c
 endif
+
+ifeq ($(CONFIG_DRIVERS_VIRTIO_NET),y)
+CHIP_CSRCS += qemu_rv_virtio.c
+endif

arch/risc-v/src/qemu-rv/qemu_rv_virtio.c

@@ -0,0 +1,40 @@
+/****************************************************************************
+ * arch/risc-v/src/qemu-rv/qemu_rv_virtio.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <syslog.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/virtio/virtio-mmio.h>
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+void riscv_netinitialize(void)
+{
+  virtio_mmio_init();
+}