core: split out library code

This commit splits core into it's scheduler/IPC part and into other code
that is either used or uses the scheduler, through defined APIs.

Makefile.include

@@ -407,7 +407,10 @@ ifneq (,$(IOTLAB_NODE))
 endif
 
 # Add standard include directories
-INCLUDES += -I$(RIOTBASE)/core/include -I$(RIOTBASE)/drivers/include -I$(RIOTBASE)/sys/include
+INCLUDES += -I$(RIOTBASE)/core/lib/include
+INCLUDES += -I$(RIOTBASE)/core/include
+INCLUDES += -I$(RIOTBASE)/drivers/include
+INCLUDES += -I$(RIOTBASE)/sys/include
 
 # process provided features
 include $(RIOTBASE)/Makefile.features

boards/native/Makefile.include

@@ -1,5 +1,6 @@
 NATIVEINCLUDES += -DNATIVE_INCLUDES
 NATIVEINCLUDES += -I$(RIOTBOARD)/native/include/
+NATIVEINCLUDES += -I$(RIOTBASE)/core/lib/include/
 NATIVEINCLUDES += -I$(RIOTBASE)/core/include/
 NATIVEINCLUDES += -I$(RIOTBASE)/drivers/include/
 

core/Makefile

@@ -1,5 +1,5 @@
 # exclude submodule sources from *.c wildcard source selection
-SRC := $(filter-out init.c mbox.c msg.c msg_bus.c panic.c thread_flags.c,$(wildcard *.c))
+SRC := $(filter-out mbox.c msg.c msg_bus.c thread_flags.c,$(wildcard *.c))
 
 # enable submodules
 SUBMODULES := 1

core/lib/Makefile

@@ -0,0 +1,12 @@
+MODULE = core_lib
+
+# enable submodules
+SUBMODULES := 1
+# set this so the panic and init code is available as "core_panic" and "core_init"
+# instead of "core_lib_..."
+BASE_MODULE = core
+
+# exclude submodule sources from *.c wildcard source selection
+SRC := $(filter-out panic.c init.c,$(wildcard *.c))
+
+include $(RIOTBASE)/Makefile.base

makefiles/application.inc.mk

@@ -1,7 +1,7 @@
 MODULE = $(APPLICATION_MODULE)
 
 DIRS += $(RIOTCPU)/$(CPU) $(BOARDDIR)
-DIRS += $(RIOTBASE)/core $(RIOTBASE)/drivers $(RIOTBASE)/sys
+DIRS += $(RIOTBASE)/core $(RIOTBASE)/core/lib $(RIOTBASE)/drivers $(RIOTBASE)/sys
 
 # For regular modules, adding files to BLOBS to their Makefile is sufficient to
 # create the corresponding headers.

makefiles/defaultmodules.inc.mk

@@ -1,4 +1,7 @@
-DEFAULT_MODULE += board board_common_init cpu core core_init core_msg core_panic sys
+DEFAULT_MODULE += board board_common_init \
+                  cpu \
+                  core core_init core_lib core_msg core_panic \
+                  sys
 
 # Include potentially added default modules by the board
 -include $(BOARDDIR)/Makefile.default

makefiles/pseudomodules.inc.mk

@@ -274,6 +274,9 @@ PSEUDOMODULES += ztimer64_%
 ## configuration header board.h. These can be found out by running tests/ztimer_overhead
 PSEUDOMODULES += ztimer_auto_adjust
 
+# core_lib is not a submodule
+NO_PSEUDOMODULES += core_lib
+
 # ztimer's main module is called "ztimer_core"
 NO_PSEUDOMODULES += ztimer_core
 NO_PSEUDOMODULES += netdev_ieee802154_submac