1. 根目录:
2. scripts
3. mod
4. Makefile

hostprogs-y	:= modpost mk_elfconfig
always		:= $(hostprogs-y) empty.o

modpost-objs	:= modpost.o file2alias.o sumversion.o

devicetable-offsets-file := devicetable-offsets.h

define sed-y
	"/^->/{s:->#\(.*\):/* \1 */:; \
	s:^->\([^ ]*\) [\$$#]*\([-0-9]*\) \(.*\):#define \1 \2 /* \3 */:; \
	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
	s:->::; p;}"
endef

quiet_cmd_offsets = GEN     $@
define cmd_offsets
	(set -e; \
	 echo "#ifndef __DEVICETABLE_OFFSETS_H__"; \
	 echo "#define __DEVICETABLE_OFFSETS_H__"; \
	 echo "/*"; \
	 echo " * DO NOT MODIFY."; \
	 echo " *"; \
	 echo " * This file was generated by Kbuild"; \
	 echo " *"; \
	 echo " */"; \
	 echo ""; \
	 sed -ne $(sed-y) $<; \
	 echo ""; \
	 echo "#endif" ) > $@
endef

$(obj)/$(devicetable-offsets-file): $(obj)/devicetable-offsets.s
	$(call if_changed,offsets)

targets += $(devicetable-offsets-file) devicetable-offsets.s

# dependencies on generated files need to be listed explicitly

$(obj)/modpost.o $(obj)/file2alias.o $(obj)/sumversion.o: $(obj)/elfconfig.h
$(obj)/file2alias.o: $(obj)/$(devicetable-offsets-file)

quiet_cmd_elfconfig = MKELF   $@
      cmd_elfconfig = $(obj)/mk_elfconfig < $< > $@

$(obj)/elfconfig.h: $(obj)/empty.o $(obj)/mk_elfconfig FORCE
	$(call if_changed,elfconfig)

targets += elfconfig.h