lwext4: add port of ext2/3/4 filesystem library

Besides the missing supported features noted in the README, missing
support for extending files via truncation/seeking might limit its
application.

Issue #124.

include/lwext4/init.h

@@ -0,0 +1,36 @@
+/*
+ * \brief  Initialize functions
+ * \author Josef Soentgen
+ * \date   2017-08-01
+ */
+
+/*
+ * Copyright (C) 2017 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+#ifndef _INCLUDE__LWEXT4_INIT_H_
+#define _INCLUDE__LWEXT4_INIT_H_
+
+/* Genode includes */
+#include <base/exception.h>
+
+namespace Genode {
+	struct Env;
+	struct Allocator;
+}
+
+struct ext4_blockdev;
+
+namespace Lwext4 {
+
+	struct Block_init_failed  : Genode::Exception { };
+	struct Malloc_init_failed : Genode::Exception { };
+
+	void malloc_init(Genode::Env &, Genode::Allocator &heap);
+	struct ext4_blockdev *block_init(Genode::Env &, Genode::Allocator &heap);
+}
+
+#endif /* _INCLUDE__LWEXT4_INIT_H_ */