# SPDX-License-Identifier: GPL-2.0#### Main build makefile.##  Lots of this code have been borrowed or heavily inspired from parts#  of kbuild code, which is not credited, but mostly developed by:##  Copyright (C) Sam Ravnborg <sam@mars.ravnborg.org>, 2015#  Copyright (C) Linus Torvalds <torvalds@linux-foundation.org>, 2015# PHONY := __build__build: build-dir := $(srctree)/tools/build # Define $(fixdep) for dep-cmd functionifeq ($(OUTPUT),)  fixdep := $(build-dir)/fixdepelse  fixdep := $(OUTPUT)/fixdependif # Generic definitionsinclude $(build-dir)/Build.include # do not force detected configuration-include $(OUTPUT).config-detected # Init all relevant variables used in build files so# 1) they have correct type# 2) they do not inherit any value from the environmentsubdir-y     :=obj-y        :=subdir-y     :=subdir-obj-y := # Build definitionsbuild-file := $(dir)/Build-include $(build-file) quiet_cmd_flex  = FLEX    $@quiet_cmd_bison = BISON   $@quiet_cmd_test  = TEST    $@ # Create directory unless it existsquiet_cmd_mkdir = MKDIR   $(dir $@)      cmd_mkdir = mkdir -p $(dir $@)     rule_mkdir = $(if $(wildcard $(dir $@)),,@$(call echo-cmd,mkdir) $(cmd_mkdir)) # Compile commandquiet_cmd_cc_o_c = CC      $@      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< quiet_cmd_host_cc_o_c = HOSTCC  $@      cmd_host_cc_o_c = $(HOSTCC) $(host_c_flags) -c -o $@ $< quiet_cmd_cxx_o_c = CXX     $@      cmd_cxx_o_c = $(CXX) $(cxx_flags) -c -o $@ $< quiet_cmd_cpp_i_c = CPP     $@      cmd_cpp_i_c = $(CC) $(c_flags) -E -o $@ $< quiet_cmd_cc_s_c = AS      $@      cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $< quiet_cmd_gen = GEN     $@ # Link agregate command# If there's nothing to link, create empty $@ object.quiet_cmd_ld_multi = LD      $@      cmd_ld_multi = $(if $(strip $(obj-y)),\                     printf "$(objprefix)%s " $(patsubst $(objprefix)%,%,$(filter $(obj-y),$^)) | \                     xargs $(LD) -r -o $@,rm -f $@; $(AR) rcs $@) quiet_cmd_host_ld_multi = HOSTLD  $@      cmd_host_ld_multi = $(if $(strip $(obj-y)),\                          printf "$(objprefix)%s " $(patsubst $(objprefix)%,%,$(filter $(obj-y),$^)) | \                          xargs $(HOSTLD) -r -o $@,rm -f $@; $(HOSTAR) rcs $@) rust_common_cmd = \	$(RUSTC) $(rust_flags) \	--crate-type staticlib -L $(objtree)/rust/ \	--emit=dep-info=$(depfile),link quiet_cmd_rustc_a_rs = $(RUSTC) $(quiet_modtag) $@      cmd_rustc_a_rs = $(rust_common_cmd) -o $@ -g $< $(cmd_objtool) ifneq ($(filter $(obj),$(hostprogs)),)  host = host_endif # Build rules$(OUTPUT)%.o: %.c FORCE	$(call rule_mkdir)	$(call if_changed_dep,$(host)cc_o_c) $(OUTPUT)%.o: %.cpp FORCE	$(call rule_mkdir)	$(call if_changed_dep,cxx_o_c) $(OUTPUT)%.o: %.S FORCE	$(call rule_mkdir)	$(call if_changed_dep,$(host)cc_o_c) $(OUTPUT)%.i: %.c FORCE	$(call rule_mkdir)	$(call if_changed_dep,cpp_i_c) $(OUTPUT)%.s: %.S FORCE	$(call rule_mkdir)	$(call if_changed_dep,cpp_i_c) $(OUTPUT)%.s: %.c FORCE	$(call rule_mkdir)	$(call if_changed_dep,cc_s_c) # it's recommended to build a static rust library, when a foreight (to rust)# linker is used.$(OUTPUT)%.a: %.rs FORCE	$(call rule_mkdir)	$(call if_changed_dep,rustc_a_rs) # bison and flex files are generated in the OUTPUT directory# so it needs a separate rule to depend on them properly$(OUTPUT)%-bison.o: $(OUTPUT)%-bison.c FORCE	$(call rule_mkdir)	$(call if_changed_dep,$(host)cc_o_c) $(OUTPUT)%-flex.o: $(OUTPUT)%-flex.c FORCE	$(call rule_mkdir)	$(call if_changed_dep,$(host)cc_o_c) # Gather build data:#   obj-y        - list of build objects#   subdir-y     - list of directories to nest#   subdir-obj-y - list of directories objects 'dir/$(obj)-in.o'obj-y        := $($(obj)-y)subdir-y     := $(patsubst %/,%,$(filter %/, $(obj-y)))obj-y        := $(patsubst %/, %/$(obj)-in.o, $(obj-y))subdir-obj-y := $(filter %/$(obj)-in.o, $(obj-y)) # '$(OUTPUT)/dir' prefix to all objectsobjprefix    := $(subst ./,,$(OUTPUT)$(dir)/)obj-y        := $(addprefix $(objprefix),$(obj-y))subdir-obj-y := $(addprefix $(objprefix),$(subdir-obj-y)) # Separate out test log files from real build objects.test-y       := $(filter %_log, $(obj-y))obj-y        := $(filter-out %_log, $(obj-y)) # Final '$(obj)-in.o' objectin-target := $(objprefix)$(obj)-in.o PHONY += $(subdir-y) $(subdir-y):	$(Q)$(MAKE) -f $(build-dir)/Makefile.build dir=$(dir)/$@ obj=$(obj) $(sort $(subdir-obj-y)): $(subdir-y) ; $(in-target): $(obj-y) $(test-y) FORCE	$(call rule_mkdir)	$(call if_changed,$(host)ld_multi) __build: $(in-target)	@: PHONY += FORCEFORCE: # Include all cmd files to get all the dependency rules# for all objects includedtargets   := $(wildcard $(sort $(obj-y) $(in-target) $(MAKECMDGOALS)))cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),)  include $(cmd_files)endif .PHONY: $(PHONY)