From 6f05daceb3605280671846e3f1681bf268fdf7a6 Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Wed, 16 Nov 2022 13:21:50 +0100
Subject: [PATCH] cpu/stm32: add unused backup RAM as extra heap

---
 cpu/stm32/include/cpu_conf.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/cpu/stm32/include/cpu_conf.h b/cpu/stm32/include/cpu_conf.h
index e89fd40a4572..9f14da6869dd 100644
--- a/cpu/stm32/include/cpu_conf.h
+++ b/cpu/stm32/include/cpu_conf.h
@@ -78,6 +78,11 @@
 #error Not supported CPU family
 #endif
 
+/* add unused backup RAM as extra heap */
+#if !defined(NUM_HEAPS) && CPU_HAS_BACKUP_RAM
+#define NUM_HEAPS   2
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif