4 # Lots of this code have been borrowed or heavily inspired from parts
5 # of kbuild code, which is not credited, but mostly developed by:
7 # Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015
8 # Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015
20 build-dir := $(srctree)/tools/build
23 include $(build-dir)/Build.include
25 # do not force detected configuration
26 -include .config-detected
28 # Init all relevant variables used in build files so
29 # 1) they have correct type
30 # 2) they do not inherit any value from the environment
37 build-file := $(dir)/Build
40 quiet_cmd_flex = FLEX $@
41 quiet_cmd_bison = BISON $@
43 # Create directory unless it exists
44 quiet_cmd_mkdir = MKDIR $(dir $@)
45 cmd_mkdir = mkdir -p $(dir $@)
46 rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir))
49 quiet_cmd_cc_o_c = CC $@
50 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
52 # Link agregate command
53 # If there's nothing to link, create empty $@ object.
54 quiet_cmd_ld_multi = LD $@
55 cmd_ld_multi = $(if $(strip $(obj-y)),\
56 $(LD) -r -o $@ $(obj-y),rm -f $@; $(AR) rcs $@)
59 $(OUTPUT)%.o: %.c FORCE
61 $(call if_changed_dep,cc_o_c)
63 $(OUTPUT)%.o: %.S FORCE
65 $(call if_changed_dep,cc_o_c)
68 # obj-y - list of build objects
69 # subdir-y - list of directories to nest
70 # subdir-obj-y - list of directories objects 'dir/$(obj)-in.o'
72 subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y)))
73 obj-y := $(patsubst %/, %/$(obj)-in.o, $(obj-y))
74 subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y))
76 # '$(OUTPUT)/dir' prefix to all objects
77 prefix := $(subst ./,,$(OUTPUT)$(dir)/)
78 obj-y := $(addprefix $(prefix),$(obj-y))
79 subdir-obj-y := $(addprefix $(prefix),$(subdir-obj-y))
81 # Final '$(obj)-in.o' object
82 in-target := $(prefix)$(obj)-in.o
87 @$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj)
89 $(sort $(subdir-obj-y)): $(subdir-y) ;
91 $(in-target): $(obj-y) FORCE
93 $(call if_changed,ld_multi)
101 # Include all cmd files to get all the dependency rules
102 # for all objects included
103 targets := $(wildcard $(sort $(obj-y) $(in-target)))
104 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
106 ifneq ($(cmd_files),)