# SPDX-License-Identifier: GPL-2.0# ==========================================================================# Building# ========================================================================== src := $(obj) PHONY := __build__build: # Init all relevant variables used in kbuild files so# 1) they have correct type# 2) they do not inherit any value from the environmentobj-y :=obj-m :=lib-y :=lib-m :=always-y :=always-m :=targets :=subdir-y :=subdir-m :=EXTRA_AFLAGS   :=EXTRA_CFLAGS   :=EXTRA_CPPFLAGS :=EXTRA_LDFLAGS  :=asflags-y  :=ccflags-y  :=cppflags-y :=ldflags-y  := subdir-asflags-y :=subdir-ccflags-y := # Read auto.conf if it exists, otherwise ignore-include include/config/auto.conf include $(srctree)/scripts/Kbuild.includeinclude $(srctree)/scripts/Makefile.compiler # The filename Kbuild has precedence over Makefilekbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile) include $(srctree)/scripts/Makefile.lib # Do not include hostprogs rules unless needed.# $(sort ...) is used here to remove duplicated words and excessive spaces.hostprogs := $(sort $(hostprogs))ifneq ($(hostprogs),)include $(srctree)/scripts/Makefile.hostendif # Do not include userprogs rules unless needed.# $(sort ...) is used here to remove duplicated words and excessive spaces.userprogs := $(sort $(userprogs))ifneq ($(userprogs),)include $(srctree)/scripts/Makefile.userprogsendif ifndef obj$(warning kbuild: Makefile.build is included improperly)endif ifeq ($(need-modorder),)ifneq ($(obj-m),)$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)endifendif # =========================================================================== # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))subdir-modorder := $(sort $(filter %/modules.order, $(obj-m))) targets-for-builtin := $(extra-y) ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)targets-for-builtin += $(obj)/lib.aendif ifdef need-builtintargets-for-builtin += $(obj)/built-in.aendif targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \				$(patsubst %.o, %.$x, $(filter %.o, $(obj-m)))) ifdef need-modordertargets-for-modules += $(obj)/modules.orderendif targets += $(targets-for-builtin) $(targets-for-modules) # Linus' kernel sanity checking toolifeq ($(KBUILD_CHECKSRC),1)  quiet_cmd_checksrc       = CHECK   $<        cmd_checksrc       = $(CHECK) $(CHECKFLAGS) $(c_flags) $<else ifeq ($(KBUILD_CHECKSRC),2)  quiet_cmd_force_checksrc = CHECK   $<        cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<endif ifneq ($(KBUILD_EXTRA_WARN),)  cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<endif # Compile C sources (.c)# --------------------------------------------------------------------------- quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $< $(obj)/%.s: $(src)/%.c FORCE	$(call if_changed_dep,cc_s_c) quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@cmd_cpp_i_c       = $(CPP) $(c_flags) -o $@ $< $(obj)/%.i: $(src)/%.c FORCE	$(call if_changed_dep,cpp_i_c) genksyms = scripts/genksyms/genksyms		\	$(if $(1), -T $(2))			\	$(if $(KBUILD_PRESERVE), -p)		\	-r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null) # These mirror gensymtypes_S and co below, keep them in synch.cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms) quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@      cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null $(obj)/%.symtypes : $(src)/%.c FORCE	$(call cmd,cc_symtypes_c) # LLVM assembly# Generate .ll files from .cquiet_cmd_cc_ll_c = CC $(quiet_modtag)  $@      cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $< $(obj)/%.ll: $(src)/%.c FORCE	$(call if_changed_dep,cc_ll_c) # C (.c) files# The C file is compiled and updated dependency information is generated.# (See cmd_cc_o_c + relevant part of rule_cc_o_c) is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y) # When a module consists of a single object, there is no reason to keep LLVM IR.# Make $(LD) covert LLVM IR to ELF here.ifdef CONFIG_LTO_CLANGcmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)endif quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@      cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \		$(cmd_ld_single_m) \		$(cmd_objtool) ifdef CONFIG_MODVERSIONS# When module versioning is enabled the following steps are executed:# o compile a <file>.o from <file>.c# o if <file>.o doesn't contain a __ksymtab version, i.e. does#   not export symbols, it's done.# o otherwise, we calculate symbol versions using the good old#   genksyms on the preprocessed source and dump them into the .cmd file.# o modpost will extract versions from that file and create *.c files that will#   be compiled and linked to the kernel and/or modules. gen_symversions =								\	if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then			\		$(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \			>> $(dot-target).cmd;					\	fi cmd_gen_symversions_c =	$(call gen_symversions,c) endif ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT# compiler will not generate __mcount_loc use recordmcount or recordmcount.plifdef BUILD_C_RECORDMCOUNTifeq ("$(origin RECORDMCOUNT_WARN)", "command line")  RECORDMCOUNT_FLAGS = -wendif# Due to recursion, we must skip empty.o.# The empty.o file is created in the make process in order to determine# the target endianness and word size. It is made before all other C# files, including recordmcount.sub_cmd_record_mcount =					\	if [ $(@) != "scripts/mod/empty.o" ]; then	\		$(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)";	\	fi;recordmcount_source := $(srctree)/scripts/recordmcount.c \		    $(srctree)/scripts/recordmcount.helsesub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \	"$(if $(CONFIG_64BIT),64,32)" \	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \	"$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \	"$(if $(part-of-module),1,0)" "$(@)";recordmcount_source := $(srctree)/scripts/recordmcount.plendif # BUILD_C_RECORDMCOUNTcmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\	$(sub_cmd_record_mcount))endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y) $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y)) ifdef CONFIG_TRIM_UNUSED_KSYMScmd_gen_ksymdeps = \	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmdendif cmd_check_local_export = $(srctree)/scripts/check-local-export $@ define rule_cc_o_c	$(call cmd_and_fixdep,cc_o_c)	$(call cmd,gen_ksymdeps)	$(call cmd,check_local_export)	$(call cmd,checksrc)	$(call cmd,checkdoc)	$(call cmd,gen_objtooldep)	$(call cmd,gen_symversions_c)	$(call cmd,record_mcount)endef define rule_as_o_S	$(call cmd_and_fixdep,as_o_S)	$(call cmd,gen_ksymdeps)	$(call cmd,check_local_export)	$(call cmd,gen_objtooldep)	$(call cmd,gen_symversions_S)endef # Built-in and composite module parts$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE	$(call if_changed_rule,cc_o_c)	$(call cmd,force_checksrc) # To make this rule robust against "Argument list too long" error,# ensure to add $(obj)/ prefix by a shell command.cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \	$(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@ $(obj)/%.mod: FORCE	$(call if_changed,mod) # List module undefined symbolscmd_undefined_syms = $(NM) $< | sed -n 's/^  *U //p' > $@ $(obj)/%.usyms: $(obj)/%.o FORCE	$(call if_changed,undefined_syms) quiet_cmd_cc_lst_c = MKLST   $@      cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \		     $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \				     System.map $(OBJDUMP) > $@ $(obj)/%.lst: $(src)/%.c FORCE	$(call if_changed_dep,cc_lst_c) # Compile assembler sources (.S)# --------------------------------------------------------------------------- # .S file exports must have their C prototypes defined in asm/asm-prototypes.h# or a file that it includes, in order to get versioned symbols. We build a# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from# the .S file (with trailing ';'), and run genksyms on that, to extract vers.## This is convoluted. The .S file must first be preprocessed to run guards and# expand names, then the resulting exports must be constructed into plain# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed# to make the genksyms input.## These mirror gensymtypes_c and co above, keep them in synch.cmd_gensymtypes_S =                                                         \   { echo "\#include <linux/kernel.h>" ;                                    \     echo "\#include <asm/asm-prototypes.h>" ;                              \    $(CPP) $(a_flags) $< |                                                  \     grep "\<___EXPORT_SYMBOL\>" |                                          \     sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \    $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms) quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@      cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null $(obj)/%.symtypes : $(src)/%.S FORCE	$(call cmd,cc_symtypes_S)  quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@cmd_cpp_s_S       = $(CPP) $(a_flags) -o $@ $< $(obj)/%.s: $(src)/%.S FORCE	$(call if_changed_dep,cpp_s_S) quiet_cmd_as_o_S = AS $(quiet_modtag)  $@      cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool) ifdef CONFIG_ASM_MODVERSIONS # versioning matches the C process described above, with difference that# we parse asm-prototypes.h C header to get function definitions. cmd_gen_symversions_S = $(call gen_symversions,S) endif $(obj)/%.o: $(src)/%.S FORCE	$(call if_changed_rule,as_o_S) targets += $(filter-out $(subdir-builtin), $(real-obj-y))targets += $(filter-out $(subdir-modorder), $(real-obj-m))targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS) # Linker scripts preprocessor (.lds.S -> .lds)# ---------------------------------------------------------------------------quiet_cmd_cpp_lds_S = LDS     $@      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $< $(obj)/%.lds: $(src)/%.lds.S FORCE	$(call if_changed_dep,cpp_lds_S) # ASN.1 grammar# ---------------------------------------------------------------------------quiet_cmd_asn1_compiler = ASN.1   $(basename $@).[ch]      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \				$(basename $@).c $(basename $@).h $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler	$(call cmd,asn1_compiler) # Build the compiled-in targets# --------------------------------------------------------------------------- # To build objects in subdirs, we need to descend into the directories$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ; ## Rule to compile a set of .o files into one .a file (without symbol table)## To make this rule robust against "Argument list too long" error,# remove $(obj)/ prefix, and restore it by a shell command. quiet_cmd_ar_builtin = AR      $@      cmd_ar_builtin = rm -f $@; \	$(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \	$(AR) cDPrST $@ $(obj)/built-in.a: $(real-obj-y) FORCE	$(call if_changed,ar_builtin) ## Rule to create modules.order file## Create commands to either record .ko file or cat modules.order from# a subdirectory# Add $(obj-m) as the prerequisite to avoid updating the timestamp of# modules.order unless contained modules are updated. cmd_modules_order = { $(foreach m, $(real-prereqs), \	$(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \	| $(AWK) '!x[$$0]++' - > $@ $(obj)/modules.order: $(obj-m) FORCE	$(call if_changed,modules_order) ## Rule to compile a set of .o files into one .a file (with symbol table)# $(obj)/lib.a: $(lib-y) FORCE	$(call if_changed,ar) quiet_cmd_ld_multi_m = LD [M]  $@      cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool) define rule_ld_multi_m	$(call cmd_and_savecmd,ld_multi_m)	$(call cmd,gen_objtooldep)endef $(multi-obj-m): objtool-enabled := $(delay-objtool)$(multi-obj-m): part-of-module := y$(multi-obj-m): %.o: %.mod FORCE	$(call if_changed_rule,ld_multi_m)$(call multi_depend, $(multi-obj-m), .o, -objs -y -m) targets := $(filter-out $(PHONY), $(targets)) # Add intermediate targets:# When building objects with specific suffix patterns, add intermediate# targets that the final targets are derived from.intermediate_targets = $(foreach sfx, $(2), \				$(patsubst %$(strip $(1)),%$(sfx), \					$(filter %$(strip $(1)), $(targets))))# %.asn1.o <- %.asn1.[ch] <- %.asn1# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts# %.lex.o <- %.lex.c <- %.l# %.tab.o <- %.tab.[ch] <- %.ytargets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \	   $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \	   $(call intermediate_targets, .lex.o, .lex.c) \	   $(call intermediate_targets, .tab.o, .tab.c .tab.h) # Build# --------------------------------------------------------------------------- ifdef single-build KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS)) curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \			$(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x)))) # Handle single targets without any rule: show "Nothing to be done for ..." or# "No rule to make target ..." depending on whether the target exists.unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \			$(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS))) single-subdirs := $(foreach d, $(subdir-ym), \			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d))) __build: $(curdir-single) $(single-subdirs)ifneq ($(unknown-single),)	$(Q)$(MAKE) -f /dev/null $(unknown-single)endif	@: ifeq ($(curdir-single),)# Nothing to do in this directory. Do not include any .*.cmd file for speed-uptargets :=elsetargets += $(curdir-single)endif else __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \	 $(if $(KBUILD_MODULES), $(targets-for-modules)) \	 $(subdir-ym) $(always-y)	@: endif # Descending# --------------------------------------------------------------------------- PHONY += $(subdir-ym)$(subdir-ym):	$(Q)$(MAKE) $(build)=$@ \	$(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \	need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \	need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) # Add FORCE to the prequisites of a target to force it to be always rebuilt.# --------------------------------------------------------------------------- PHONY += FORCE FORCE: # Read all saved command lines and dependencies for the $(targets) we# may be building above, using $(if_changed{,_dep}). As an# optimization, we don't need to read them if the target does not# exist, we will rebuild anyway in that case. existing-targets := $(wildcard $(sort $(targets))) -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd) # Create directories for object files if they do not existobj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))# If targets exist, their directories apparently exist. Skip mkdir.existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))ifneq ($(obj-dirs),)$(shell mkdir -p $(obj-dirs))endif .PHONY: $(PHONY)