Add tags generation/cleanup to Makefile

Makefile

@@ -36,7 +36,7 @@ ifneq (,$(SUBDIRS))
 	include $(patsubst %,%/kernel.mk,$(SUBDIRS))
 endif
 
-.PHONY: all clean boot boot-gdb
+.PHONY: all tags clean boot boot-gdb
 
 all: aedrix-kernel.img aedrix-kernel.elf
 
@@ -80,6 +80,10 @@ config.h: config
 	@sed -i 's/^\s*\(CONFIG_[A-Z0-9_]\+\)\s*=\s*[yY]/#define \1/g' config.h
 	@sed -i 's/^\s*\(CONFIG_[A-Z0-9_]\+\)\s*=\s*\([0-9]\+\)/#define \1 \2/g' config.h
 
+tags:
+	@echo ' CTAGS    tags'
+	$(V)ctags -R $(SUBDIRS)
+
 clean:
 	@echo '  CLEAN   config.h'
 	$(V)rm -f config.h
@@ -93,6 +97,8 @@ clean:
 	$(V)rm -f aedrix-kernel.objdump
 	@echo '  CLEAN   aedrix-kernel.img'
 	$(V)rm -f aedrix-kernel.img
+	@echo '  CLEAN   tags'
+	$(V)rm -f tags
 
 boot-elf: aedrix-kernel.elf
 	$(V)$(ARCH_QEMU_CMD) -kernel aedrix-kernel.elf -serial stdio