diff --git a/src/mainboard/emulation/qemu-aarch64/cbmem.c b/src/mainboard/emulation/qemu-aarch64/cbmem.c
new file mode 100644
index 0000000..c50254d
--- /dev/null
+++ b/src/mainboard/emulation/qemu-aarch64/cbmem.c
@@ -0,0 +1,16 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2019 Asami Doi <d0iasm.pub@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <cbmem.h>
+#include <ramdetect.h>
+#include <symbols.h>
+
+void *cbmem_top(void)
+{
+	return _dram + (probe_ramsize((uintptr_t)_dram, CONFIG_DRAM_SIZE_MB) * MiB);
+}