1 # SPDX-License-Identifier: GPL-2.0 2 ### 3 # Main build makefile. 4 # 5 # Lots of this code have been borrowed or heavily inspired from parts 6 # of kbuild code, which is not credited, but mostly developed by: 7 # 8 # Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015 9 # Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015 10 # 11 12 PHONY := __build 13 __build: 14 15 ifeq ($(V),1) 16 quiet = 17 Q = 18 else 19 quiet=quiet_ 20 Q=@ 21 endif 22 23 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),) 24 quiet=silent_ 25 endif 26 27 build-dir := $(srctree)/tools/build 28 29 # Define $(fixdep) for dep-cmd function 30 ifeq ($(OUTPUT),) 31 fixdep := $(build-dir)/fixdep 32 else 33 fixdep := $(OUTPUT)/fixdep 34 endif 35 36 # Generic definitions 37 include $(build-dir)/Build.include 38 39 # do not force detected configuration 40 -include $(OUTPUT).config-detected 41 42 # Init all relevant variables used in build files so 43 # 1) they have correct type 44 # 2) they do not inherit any value from the environment 45 subdir-y := 46 obj-y := 47 subdir-y := 48 subdir-obj-y := 49 50 # Build definitions 51 build-file := $(dir)/Build 52 -include $(build-file) 53 54 quiet_cmd_flex = FLEX $@ 55 quiet_cmd_bison = BISON $@ 56 quiet_cmd_test = TEST $@ 57 58 # Create directory unless it exists 59 quiet_cmd_mkdir = MKDIR $(dir $@) 60 cmd_mkdir = mkdir -p $(dir $@) 61 rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir)) 62 63 # Compile command 64 quiet_cmd_cc_o_c = CC $@ 65 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 66 67 quiet_cmd_host_cc_o_c = HOSTCC $@ 68 cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $< 69 70 quiet_cmd_cxx_o_c = CXX $@ 71 cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $< 72 73 quiet_cmd_cpp_i_c = CPP $@ 74 cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $< 75 76 quiet_cmd_cc_s_c = AS $@ 77 cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $< 78 79 quiet_cmd_gen = GEN $@ 80 81 # Link agregate command 82 # If there's nothing to link, create empty $@ object. 83 quiet_cmd_ld_multi = LD $@ 84 cmd_ld_multi = $(if $(strip $(obj-y)),\ 85 $(LD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(AR) rcs $@) 86 87 quiet_cmd_host_ld_multi = HOSTLD $@ 88 cmd_host_ld_multi = $(if $(strip $(obj-y)),\ 89 $(HOSTLD) -r -o $@ $(filter $(obj-y),$^),rm -f $@; $(HOSTAR) rcs $@) 90 91 ifneq ($(filter $(obj),$(hostprogs)),) 92 host = host_ 93 endif 94 95 # Build rules 96 $(OUTPUT)%.o: %.c FORCE 97 $(call rule_mkdir) 98 $(call if_changed_dep,$(host)cc_o_c) 99 100 $(OUTPUT)%.o: %.cpp FORCE 101 $(call rule_mkdir) 102 $(call if_changed_dep,cxx_o_c) 103 104 $(OUTPUT)%.o: %.S FORCE 105 $(call rule_mkdir) 106 $(call if_changed_dep,$(host)cc_o_c) 107 108 $(OUTPUT)%.i: %.c FORCE 109 $(call rule_mkdir) 110 $(call if_changed_dep,cpp_i_c) 111 112 $(OUTPUT)%.s: %.S FORCE 113 $(call rule_mkdir) 114 $(call if_changed_dep,cpp_i_c) 115 116 $(OUTPUT)%.s: %.c FORCE 117 $(call rule_mkdir) 118 $(call if_changed_dep,cc_s_c) 119 120 # Gather build data: 121 # obj-y - list of build objects 122 # subdir-y - list of directories to nest 123 # subdir-obj-y - list of directories objects 'dir/$(obj)-in.o' 124 obj-y := $($(obj)-y) 125 subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y))) 126 obj-y := $(patsubst %/, %/$(obj)-in.o, $(obj-y)) 127 subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y)) 128 129 # '$(OUTPUT)/dir' prefix to all objects 130 objprefix := $(subst ./,,$(OUTPUT)$(dir)/) 131 obj-y := $(addprefix $(objprefix),$(obj-y)) 132 subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y)) 133 134 # Final '$(obj)-in.o' object 135 in-target := $(objprefix)$(obj)-in.o 136 137 PHONY += $(subdir-y) 138 139 $(subdir-y): 140 $(Q)$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj) 141 142 $(sort $(subdir-obj-y)): $(subdir-y) ; 143 144 $(in-target): $(obj-y) FORCE 145 $(call rule_mkdir) 146 $(call if_changed,$(host)ld_multi) 147 148 __build: $(in-target) 149 @: 150 151 PHONY += FORCE 152 FORCE: 153 154 # Include all cmd files to get all the dependency rules 155 # for all objects included 156 targets := $(wildcard $(sort $(obj-y) $(in-target) $(MAKECMDGOALS))) 157 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 158 159 ifneq ($(cmd_files),) 160 include $(cmd_files) 161 endif 162 163 .PHONY: $(PHONY) 164