core: Add modules to Kconfig

Kconfig

@@ -25,9 +25,18 @@ rsource "$(RIOTCPU)/Kconfig"
 # The application may declare new symbols as well
 osource "$(APPDIR)/Kconfig"
 
+rsource "core/Kconfig"
 rsource "drivers/Kconfig"
 rsource "sys/Kconfig"
 rsource "pkg/Kconfig"
 
 comment "RIOT is in a migration phase."
 comment "Some configuration options may not be here. Use CFLAGS instead."
+
+config TEST_KCONFIG
+    bool
+    default y if '$(TEST_KCONFIG)' = '1'
+    help
+        This is used during the Kconfig migration to test the module dependency
+        modelling. Don't change the default value unless you know what you are
+        doing.

core/Kconfig

@@ -0,0 +1,48 @@
+# Copyright (c) 2020 HAW Hamburg
+#
+# 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.
+#
+
+menuconfig MOD_CORE
+    bool "RIOT Core"
+    default y
+    depends on TEST_KCONFIG
+    help
+        RIOT's core module. Only change this if you know what you are doing. If
+        unsure, say Y.
+
+if MOD_CORE
+
+config MOD_CORE_IDLE_THREAD
+    bool
+    prompt "Use Idle thread"  if HAS_NO_IDLE_THREAD
+    default y if !HAS_NO_IDLE_THREAD
+    help
+        Select y to include the Idle thread. This is mandatory for some CPUs.
+
+config MOD_CORE_INIT
+    bool "Kernel initialization module"
+    default y
+
+config MOD_CORE_MBOX
+    bool "Kernel message box module"
+
+config MOD_CORE_MSG
+    bool "Kernel messaging module"
+    default y
+
+config MOD_CORE_MSG_BUS
+    bool "Messaging Bus module"
+    help
+        Messaging Bus API for inter process message broadcast.
+
+config MOD_CORE_PANIC
+    bool "Kernel crash handling module"
+    default y
+
+config MOD_CORE_THREAD_FLAGS
+    bool "Thread flags"
+
+endif # MOD_CORE