1 files changed, 100 insertions, 0 deletions
diff --git a/lib/csu/common/crtbegin.c b/lib/csu/common/crtbegin.c
new file mode 100644
index 000000000000..8ef9b8923c21
--- /dev/null
+++ b/lib/csu/common/crtbegin.c
@@ -0,0 +1,100 @@
+/*-
+ * SPDX-License-Identifier: BSD-1-Clause
+ *
+ * Copyright 2018 Andrew Turner
+ *
+ * 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
+ */
+
+#include <sys/param.h>
+
+#include "crt.h"
+
+typedef void (*crt_func)(void);
+
+extern void *__dso_handle __hidden;
+
+#ifndef SHARED
+void *__dso_handle = 0;
+#else
+void *__dso_handle = &__dso_handle;
+void __cxa_finalize(void *) __weak_symbol;
+
+/*
+ * Call __cxa_finalize with the dso handle in shared objects.
+ * When we have ctors/dtors call from the dtor handler before calling
+ * any dtors, otherwise use a destructor.
+ */
+#ifndef HAVE_CTORS
+__attribute__((destructor))
+#endif
+static void
+run_cxa_finalize(void)
+{
+
+	if (__cxa_finalize != NULL)
+		__cxa_finalize(__dso_handle);
+}
+#endif
+
+/*
+ * On some architectures and toolchains we may need to call the .dtors.
+ * These are called in the order they are in the ELF file.
+ */
+#ifdef HAVE_CTORS
+static void __do_global_dtors_aux(void) __used;
+
+static crt_func __CTOR_LIST__[] __section(".ctors") __used = {
+	(crt_func)-1
+};
+static crt_func __DTOR_LIST__[] __section(".dtors") __used = {
+	(crt_func)-1
+};
+
+extern const char startof_dtors[] __asm(".startof..dtors")
+    __weak_symbol __hidden;
+extern const char sizeof_dtors[] __asm(".sizeof..dtors")
+    __weak_symbol __hidden;
+
+static void
+__do_global_dtors_aux(void)
+{
+	crt_func fn;
+	uintptr_t dtors_end;
+	int n;
+
+#ifdef SHARED
+	run_cxa_finalize();
+#endif
+
+	dtors_end = (uintptr_t)&startof_dtors + (uintptr_t)&sizeof_dtors;
+	for (n = 1;; n++) {
+		fn = __DTOR_LIST__[n];
+		if (fn == (crt_func)0 || fn == (crt_func)-1 || (dtors_end > 0 &&
+		    (uintptr_t)&__DTOR_LIST__[n] >= dtors_end))
+			break;
+		fn();
+	}
+}
+
+asm (
+    ".pushsection .fini		\n"
+    "\t" INIT_CALL_SEQ(__do_global_dtors_aux) "\n"
+    ".popsection		\n"
+);
+#endif