scripts/Makefile.build - SHIFTPHONES/kernel/common - Gitiles

 # 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 environment
 obj-y :=
 obj-m :=
 lib-y :=
 lib-m :=
 always :=
 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 scripts/Kbuild.include

 # The filename Kbuild has precedence over Makefile
 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
 include $(kbuild-file)

 include 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 scripts/Makefile.host
 endif

 # Do not include userprogs rules unless needed.
 # $(sort ...) is used here to remove duplicated words and excessive spaces.
 userprogs := $(sort $(userprogs))
 ifneq ($(userprogs),)
 include scripts/Makefile.userprogs
 endif

 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.)
 endif
 endif

 # ===========================================================================

 # 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.a
 endif

 ifdef need-builtin
 targets-for-builtin += $(obj)/built-in.a
 endif

 targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))

 ifdef need-modorder
 targets-for-modules += $(obj)/modules.order
 endif

 targets += $(targets-for-builtin) $(targets-for-modules)

 # Linus' kernel sanity checking tool
 ifeq ($(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)

 # These mirror gensymtypes_S and co below, keep them in synch.
 cmd_gensymtypes_c =                                                         \
     $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \
     scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
      $(if $(KBUILD_PRESERVE),-p)                                            \
      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))

 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
 cmd_cc_symtypes_c =                                                         \
     $(call cmd_gensymtypes_c,true,$@) >/dev/null;                           \
     test -s $@ || rm -f $@

 $(obj)/%.symtypes : $(src)/%.c FORCE
 	$(call cmd,cc_symtypes_c)

 # LLVM assembly
 # Generate .ll files from .c
 quiet_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)

 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
       cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<

 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 postprocess them in a way
 #   that they are usable as a linker script
 # o generate .tmp_<file>.o from <file>.o using the linker to
 #   replace the unresolved symbols __crc_exported_symbol with
 #   the actual value of the checksum generated by genksyms
 # o remove .tmp_<file>.o to <file>.o

 ifdef CONFIG_LTO_CLANG
 # Generate .o.symversions files for each .o with exported symbols, and link these
 # to the kernel and/or modules at the end.
 cmd_modversions_c =								\
 	if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then			\
 		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
 		    > $@.symversions;						\
 	fi;
 else
 cmd_modversions_c =								\
 	if $(OBJDUMP) -h $@ | grep -q __ksymtab; then				\
 		$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
 		    > $(@D)/.tmp_$(@F:.o=.ver);					\
 										\
 		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
 			-T $(@D)/.tmp_$(@F:.o=.ver);				\
 		mv -f $(@D)/.tmp_$(@F) $@;					\
 		rm -f $(@D)/.tmp_$(@F:.o=.ver);					\
 	fi
 endif
 endif

 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
 ifdef BUILD_C_RECORDMCOUNT
 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
   RECORDMCOUNT_FLAGS = -w
 endif
 # 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.h
 else
 sub_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.pl
 endif # BUILD_C_RECORDMCOUNT
 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)),	\
 	$(sub_cmd_record_mcount))
 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT

 ifdef CONFIG_STACK_VALIDATION
 ifneq ($(SKIP_STACK_VALIDATION),1)

 __objtool_obj := $(objtree)/tools/objtool/objtool

 objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)

 objtool_args += $(if $(part-of-module), --module,)

 ifndef CONFIG_FRAME_POINTER
 objtool_args += --no-fp
 endif
 ifdef CONFIG_GCOV_KERNEL
 objtool_args += --no-unreachable
 endif
 ifdef CONFIG_RETPOLINE
   objtool_args += --retpoline
 endif
 ifdef CONFIG_X86_SMAP
   objtool_args += --uaccess
 endif

 # '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
 cmd_objtool = $(if $(patsubst y%,, \
 	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
 	$(__objtool_obj) $(objtool_args) $@)
 objtool_obj = $(if $(patsubst y%,, \
 	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
 	$(__objtool_obj))

 endif # SKIP_STACK_VALIDATION
 endif # CONFIG_STACK_VALIDATION

 # Rebuild all objects when objtool changes, or is enabled/disabled.
 objtool_dep = $(objtool_obj)					\
 	      $(wildcard include/config/orc/unwinder.h		\
 			 include/config/stack/validation.h)

 ifdef CONFIG_TRIM_UNUSED_KSYMS
 cmd_gen_ksymdeps = \
 	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd

 # List module undefined symbols
 undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
 endif

 define rule_cc_o_c
 	$(call cmd_and_fixdep,cc_o_c)
 	$(call cmd,gen_ksymdeps)
 	$(call cmd,checksrc)
 	$(call cmd,checkdoc)
 	$(call cmd,objtool)
 	$(call cmd,modversions_c)
 	$(call cmd,record_mcount)
 endef

 define rule_as_o_S
 	$(call cmd_and_fixdep,as_o_S)
 	$(call cmd,gen_ksymdeps)
 	$(call cmd,objtool)
 	$(call cmd,modversions_S)
 endef

 # Built-in and composite module parts
 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
 	$(call if_changed_rule,cc_o_c)
 	$(call cmd,force_checksrc)

 cmd_mod = { \
 	echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
 	$(undefined_syms) echo; \
 	} > $@

 $(obj)/%.mod: $(obj)/%.o FORCE
 	$(call if_changed,mod)

 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 - |                                \
     scripts/genksyms/genksyms $(if $(1), -T $(2))                           \
      $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS))                             \
      $(if $(KBUILD_PRESERVE),-p)                                            \
      -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))

 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
 cmd_cc_symtypes_S =                                                         \
     $(call cmd_gensymtypes_S,true,$@) >/dev/null;                           \
     test -s $@ || rm -f $@

 $(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 $@ $<

 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_modversions_S =								\
 	if $(OBJDUMP) -h $@ | grep -q __ksymtab; then				\
 		$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\
 		    > $(@D)/.tmp_$(@F:.o=.ver);					\
 										\
 		$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ 		\
 			-T $(@D)/.tmp_$(@F:.o=.ver);				\
 		mv -f $(@D)/.tmp_$(@F) $@;					\
 		rm -f $(@D)/.tmp_$(@F:.o=.ver);					\
 	fi
 endif

 $(obj)/%.o: $(src)/%.S $(objtool_dep) 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 += $(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)/% ;

 # combine symversions for later processing
 quiet_cmd_update_lto_symversions = SYMVER  $@
 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
       cmd_update_lto_symversions =					\
 	rm -f $@.symversions						\
 	$(foreach n, $(filter-out FORCE,$^),				\
 		$(if $(wildcard $(n).symversions),			\
 			; cat $(n).symversions >> $@.symversions))
 else
       cmd_update_lto_symversions = echo >/dev/null
 endif

 #
 # Rule to compile a set of .o files into one .a file (without symbol table)
 #

 quiet_cmd_ar_builtin = AR      $@
       cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)

 quiet_cmd_ar_and_symver = AR      $@
       cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)

 $(obj)/built-in.a: $(real-obj-y) FORCE
 	$(call if_changed,ar_and_symver)

 #
 # 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)
 #
 quiet_cmd_ar_lib = AR      $@
       cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)

 $(obj)/lib.a: $(lib-y) FORCE
 	$(call if_changed,ar_lib)

 # NOTE:
 # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
 # module is turned into a multi object module, $^ will contain header file
 # dependencies recorded in the .*.cmd file.
 ifdef CONFIG_LTO_CLANG
 quiet_cmd_link_multi-m = AR [M]  $@
 cmd_link_multi-m =						\
 	$(cmd_update_lto_symversions);				\
 	rm -f $@; 						\
 	$(AR) cDPrsT $@ $(filter %.o,$^)
 else
 quiet_cmd_link_multi-m = LD [M]  $@
       cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
 endif

 $(multi-used-m): FORCE
 	$(call if_changed,link_multi-m)
 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)

 targets += $(multi-used-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] <- %.y
 targets += $(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-up
 targets :=
 else
 targets += $(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 exist
 obj-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)
	# 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 environment
	obj-y :=
	obj-m :=
	lib-y :=
	lib-m :=
	always :=
	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 scripts/Kbuild.include

	# The filename Kbuild has precedence over Makefile
	kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
	kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
	include $(kbuild-file)

	include 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 scripts/Makefile.host
	endif

	# Do not include userprogs rules unless needed.
	# $(sort ...) is used here to remove duplicated words and excessive spaces.
	userprogs := $(sort $(userprogs))
	ifneq ($(userprogs),)
	include scripts/Makefile.userprogs
	endif

	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.)
	endif
	endif

	# ===========================================================================

	# 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.a
	endif

	ifdef need-builtin
	targets-for-builtin += $(obj)/built-in.a
	endif

	targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))

	ifdef need-modorder
	targets-for-modules += $(obj)/modules.order
	endif

	targets += $(targets-for-builtin) $(targets-for-modules)

	# Linus' kernel sanity checking tool
	ifeq ($(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)

	# These mirror gensymtypes_S and co below, keep them in synch.
	cmd_gensymtypes_c = \
	$(CPP) -D__GENKSYMS__ $(c_flags) $< \| \
	scripts/genksyms/genksyms $(if $(1), -T $(2)) \
	$(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
	$(if $(KBUILD_PRESERVE),-p) \
	-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))

	quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
	cmd_cc_symtypes_c = \
	$(call cmd_gensymtypes_c,true,$@) >/dev/null; \
	test -s $@ \|\| rm -f $@

	$(obj)/%.symtypes : $(src)/%.c FORCE
	$(call cmd,cc_symtypes_c)

	# LLVM assembly
	# Generate .ll files from .c
	quiet_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)

	quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
	cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<

	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 postprocess them in a way
	# that they are usable as a linker script
	# o generate .tmp_<file>.o from <file>.o using the linker to
	# replace the unresolved symbols __crc_exported_symbol with
	# the actual value of the checksum generated by genksyms
	# o remove .tmp_<file>.o to <file>.o

	ifdef CONFIG_LTO_CLANG
	# Generate .o.symversions files for each .o with exported symbols, and link these
	# to the kernel and/or modules at the end.
	cmd_modversions_c = \
	if $(NM) $@ 2>/dev/null \| grep -q __ksymtab; then \
	$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
	> $@.symversions; \
	fi;
	else
	cmd_modversions_c = \
	if $(OBJDUMP) -h $@ \| grep -q __ksymtab; then \
	$(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
	> $(@D)/.tmp_$(@F:.o=.ver); \
	\
	$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
	-T $(@D)/.tmp_$(@F:.o=.ver); \
	mv -f $(@D)/.tmp_$(@F) $@; \
	rm -f $(@D)/.tmp_$(@F:.o=.ver); \
	fi
	endif
	endif

	ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
	# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
	ifdef BUILD_C_RECORDMCOUNT
	ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
	RECORDMCOUNT_FLAGS = -w
	endif
	# 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.h
	else
	sub_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.pl
	endif # BUILD_C_RECORDMCOUNT
	cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
	$(sub_cmd_record_mcount))
	endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT

	ifdef CONFIG_STACK_VALIDATION
	ifneq ($(SKIP_STACK_VALIDATION),1)

	__objtool_obj := $(objtree)/tools/objtool/objtool

	objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)

	objtool_args += $(if $(part-of-module), --module,)

	ifndef CONFIG_FRAME_POINTER
	objtool_args += --no-fp
	endif
	ifdef CONFIG_GCOV_KERNEL
	objtool_args += --no-unreachable
	endif
	ifdef CONFIG_RETPOLINE
	objtool_args += --retpoline
	endif
	ifdef CONFIG_X86_SMAP
	objtool_args += --uaccess
	endif

	# '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
	cmd_objtool = $(if $(patsubst y%,, \
	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
	$(__objtool_obj) $(objtool_args) $@)
	objtool_obj = $(if $(patsubst y%,, \
	$(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
	$(__objtool_obj))

	endif # SKIP_STACK_VALIDATION
	endif # CONFIG_STACK_VALIDATION

	# Rebuild all objects when objtool changes, or is enabled/disabled.
	objtool_dep = $(objtool_obj) \
	$(wildcard include/config/orc/unwinder.h \
	include/config/stack/validation.h)

	ifdef CONFIG_TRIM_UNUSED_KSYMS
	cmd_gen_ksymdeps = \
	$(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd

	# List module undefined symbols
	undefined_syms = $(NM) $< \| $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
	endif

	define rule_cc_o_c
	$(call cmd_and_fixdep,cc_o_c)
	$(call cmd,gen_ksymdeps)
	$(call cmd,checksrc)
	$(call cmd,checkdoc)
	$(call cmd,objtool)
	$(call cmd,modversions_c)
	$(call cmd,record_mcount)
	endef

	define rule_as_o_S
	$(call cmd_and_fixdep,as_o_S)
	$(call cmd,gen_ksymdeps)
	$(call cmd,objtool)
	$(call cmd,modversions_S)
	endef

	# Built-in and composite module parts
	$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
	$(call if_changed_rule,cc_o_c)
	$(call cmd,force_checksrc)

	cmd_mod = { \
	echo $(if $($-objs)$($-y)$($-m), $(addprefix $(obj)/, $($-objs) $($-y) $($-m)), $(@:.mod=.o)); \
	$(undefined_syms) echo; \
	} > $@

	$(obj)/%.mod: $(obj)/%.o FORCE
	$(call if_changed,mod)

	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 - \| \
	scripts/genksyms/genksyms $(if $(1), -T $(2)) \
	$(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
	$(if $(KBUILD_PRESERVE),-p) \
	-r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))

	quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
	cmd_cc_symtypes_S = \
	$(call cmd_gensymtypes_S,true,$@) >/dev/null; \
	test -s $@ \|\| rm -f $@

	$(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 $@ $<

	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_modversions_S = \
	if $(OBJDUMP) -h $@ \| grep -q __ksymtab; then \
	$(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
	> $(@D)/.tmp_$(@F:.o=.ver); \
	\
	$(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
	-T $(@D)/.tmp_$(@F:.o=.ver); \
	mv -f $(@D)/.tmp_$(@F) $@; \
	rm -f $(@D)/.tmp_$(@F:.o=.ver); \
	fi
	endif

	$(obj)/%.o: $(src)/%.S $(objtool_dep) 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 += $(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)/% ;

	# combine symversions for later processing
	quiet_cmd_update_lto_symversions = SYMVER $@
	ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
	cmd_update_lto_symversions = \
	rm -f $@.symversions \
	$(foreach n, $(filter-out FORCE,$^), \
	$(if $(wildcard $(n).symversions), \
	; cat $(n).symversions >> $@.symversions))
	else
	cmd_update_lto_symversions = echo >/dev/null
	endif

	#
	# Rule to compile a set of .o files into one .a file (without symbol table)
	#

	quiet_cmd_ar_builtin = AR $@
	cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)

	quiet_cmd_ar_and_symver = AR $@
	cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)

	$(obj)/built-in.a: $(real-obj-y) FORCE
	$(call if_changed,ar_and_symver)

	#
	# 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)
	#
	quiet_cmd_ar_lib = AR $@
	cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)

	$(obj)/lib.a: $(lib-y) FORCE
	$(call if_changed,ar_lib)

	# NOTE:
	# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
	# module is turned into a multi object module, $^ will contain header file
	# dependencies recorded in the .*.cmd file.
	ifdef CONFIG_LTO_CLANG
	quiet_cmd_link_multi-m = AR [M] $@
	cmd_link_multi-m = \
	$(cmd_update_lto_symversions); \
	rm -f $@; \
	$(AR) cDPrsT $@ $(filter %.o,$^)
	else
	quiet_cmd_link_multi-m = LD [M] $@
	cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
	endif

	$(multi-used-m): FORCE
	$(call if_changed,link_multi-m)
	$(call multi_depend, $(multi-used-m), .o, -objs -y -m)

	targets += $(multi-used-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] <- %.y
	targets += $(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-up
	targets :=
	else
	targets += $(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 exist
	obj-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)