Add a stub implemenation for _fini() (#257)

build_tools/third_party/libopencm3/CMakeLists.txt

@@ -18,6 +18,7 @@ add_library(stm32f4 STATIC IMPORTED GLOBAL)
 target_sources(stm32f4
   INTERFACE
     ${libopencm3-custom_SOURCE_DIR}/vector.c
+    ${libopencm3-custom_SOURCE_DIR}/fini.c
 )
 add_dependencies(stm32f4 libopencm3_stm32f4)
 set_property(TARGET stm32f4

third_party/libopencm3-custom/fini.c

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2023 Fraunhofer-Gesellschaft zur Förderung der angewandten
+ *                Forschung e.V.
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ */
+
+void _fini(){};