From 810a06903a018c1fb466377e27b450c6bbcae2c7 Mon Sep 17 00:00:00 2001
From: Bas Stottelaar <basstottelaar@gmail.com>
Date: Wed, 9 Jan 2019 23:06:29 +0100
Subject: [PATCH 1/2] sys: stdio_null: add null driver

---
 Makefile.dep                |  2 +-
 sys/stdio_null/Makefile     |  5 ++++
 sys/stdio_null/stdio_null.c | 53 +++++++++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 1 deletion(-)
 create mode 100644 sys/stdio_null/Makefile
 create mode 100644 sys/stdio_null/stdio_null.c

diff --git a/Makefile.dep b/Makefile.dep
index 6ebede633f..ed92ed9dc0 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -403,7 +403,7 @@ ifneq (,$(filter newlib,$(USEMODULE)))
   ifeq (,$(filter newlib_syscalls_%,$(USEMODULE)))
     USEMODULE += newlib_syscalls_default
   endif
-  ifeq (,$(filter stdio_rtt stdio_cdc_acm,$(USEMODULE)))
+  ifeq (,$(filter stdio_cdc_acm stdio_null stdio_rtt,$(USEMODULE)))
     USEMODULE += stdio_uart
   endif
 endif
diff --git a/sys/stdio_null/Makefile b/sys/stdio_null/Makefile
new file mode 100644
index 0000000000..ee28b8423d
--- /dev/null
+++ b/sys/stdio_null/Makefile
@@ -0,0 +1,5 @@
+ifeq ($(DEVELHELP),1)
+  $(warning STDIO disabled via stdio_null, but DEVELHELP enabled)
+endif
+
+include $(RIOTBASE)/Makefile.base
diff --git a/sys/stdio_null/stdio_null.c b/sys/stdio_null/stdio_null.c
new file mode 100644
index 0000000000..2f55deac4c
--- /dev/null
+++ b/sys/stdio_null/stdio_null.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2019 Bas Stottelaar <basstottelaar@gmail.com>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     sys
+ * @{
+ *
+ * @file
+ * @brief       STDIO null driver
+ *
+ * This file provides a null driver for STDIO that does not depend on anything.
+ *
+ * @author      Bas Stottelaar <basstottelaar@gmail.com>
+ *
+ * @}
+ */
+
+#include "stdio_base.h"
+
+#if MODULE_VFS
+#include "vfs.h"
+#endif
+
+#define ENABLE_DEBUG 0
+#include "debug.h"
+
+void stdio_init(void)
+{
+#if MODULE_VFS
+    vfs_bind_stdio();
+#endif
+}
+
+ssize_t stdio_read(void* buffer, size_t count)
+{
+    (void) buffer;
+    (void) count;
+
+    return 0;
+}
+
+ssize_t stdio_write(const void* buffer, size_t len)
+{
+    (void) buffer;
+    (void) len;
+
+    return 0;
+}

From 05bdab80e04ee6a704c84d42addad1006ce6698f Mon Sep 17 00:00:00 2001
From: Bas Stottelaar <basstottelaar@gmail.com>
Date: Tue, 19 Nov 2019 18:27:57 +0100
Subject: [PATCH 2/2] tests: minimal: use stdio_null

---
 tests/minimal/Makefile | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/minimal/Makefile b/tests/minimal/Makefile
index 9bb62e0d41..83ace9d96d 100644
--- a/tests/minimal/Makefile
+++ b/tests/minimal/Makefile
@@ -5,4 +5,6 @@ CFLAGS += -DNDEBUG -DLOG_LEVEL=LOG_NONE
 
 DISABLE_MODULE += auto_init
 
+USEMODULE += stdio_null
+
 include $(RIOTBASE)/Makefile.include