diff --git a/fdts/stm32mp135f-dk-fw-config.dts b/fdts/stm32mp135f-dk-fw-config.dts
new file mode 100644
index 0000000..21f8242
--- /dev/null
+++ b/fdts/stm32mp135f-dk-fw-config.dts
@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ * Copyright (c) 2022, STMicroelectronics - All Rights Reserved
+ */
+
+#define DDR_SIZE	0x20000000 /* 512MB */
+#include "stm32mp13-fw-config.dtsi"