From 8f7a320aea4eaaa4b607fa64200ffb50463be805 Mon Sep 17 00:00:00 2001
From: Kaspar Schleiser <kaspar@schleiser.de>
Date: Mon, 8 Jun 2020 15:14:21 +0200
Subject: [PATCH] fixup! core: make idle thread optional

---
 Makefile.dep                      | 3 +++
 makefiles/defaultmodules.inc.mk   | 4 +---
 makefiles/features_modules.inc.mk | 5 +++++
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/Makefile.dep b/Makefile.dep
index a8183c5f2f87e..ce9cd6baa42e1 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -1071,6 +1071,9 @@ FEATURES_OPTIONAL += periph_pm
 # always select provided architecture features
 FEATURES_REQUIRED += $(filter arch_%,$(FEATURES_PROVIDED))
 
+# don't use idle thread if architecture has needed support
+FEATURES_OPTIONAL += no_idle_thread
+
 ifneq (,$(filter ecc_%,$(USEMODULE)))
   USEMODULE += ecc
 endif
diff --git a/makefiles/defaultmodules.inc.mk b/makefiles/defaultmodules.inc.mk
index 18291dfa0633f..2eee5cad37c7f 100644
--- a/makefiles/defaultmodules.inc.mk
+++ b/makefiles/defaultmodules.inc.mk
@@ -1,6 +1,4 @@
-DEFAULT_MODULE += board cpu
-DEFAULT_MODULE += core core_idle_thread core_init core_msg core_panic
-DEFAULT_MODULE += sys
+DEFAULT_MODULE += board cpu core core_init core_msg core_panic sys
 
 DEFAULT_MODULE += auto_init
 
diff --git a/makefiles/features_modules.inc.mk b/makefiles/features_modules.inc.mk
index 3d69156e3547c..8a8bcbff76536 100644
--- a/makefiles/features_modules.inc.mk
+++ b/makefiles/features_modules.inc.mk
@@ -28,3 +28,8 @@ endif
 
 # select cortexm_svc pseudomodule if the corresponding feature is used
 USEMODULE += $(filter cortexm_svc, $(FEATURES_USED))
+
+# select core_idle_thread if the feature no_idle_thread is *not* used
+ifeq (, $(filter no_idle_thread, $(FEATURES_USED)))
+  USEMODULE += core_idle_thread
+endif