# ==========================================================================# 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 :=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 # For backward compatibility check that these variables do not changesave-cflags := $(CFLAGS) # The filename Kbuild has precedence over Makefilekbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)include $(kbuild-file) # If the save-* variables changed error outifeq ($(KBUILD_NOPEDANTIC),)        ifneq ("$(save-cflags)","$(CFLAGS)")                $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)        endifendif include scripts/Makefile.lib ifdef host-progsifneq ($(hostprogs-y),$(host-progs))$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)hostprogs-y += $(host-progs)endifendif # Do not include host rules unless neededifneq ($(hostprogs-y)$(hostprogs-m),)include scripts/Makefile.hostendif ifneq ($(KBUILD_SRC),)# Create output directory if not already present_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) # Create directories for object files if directory does not exist# Needed when obj-y := dir/file.o syntax is used_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))endif ifndef obj$(warning kbuild: Makefile.build is included improperly)endif # =========================================================================== ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)lib-target := $(obj)/lib.aendif ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)builtin-target := $(obj)/built-in.oendif modorder-target := $(obj)/modules.order # We keep a list of all modules in $(MODVERDIR) __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \	 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \	 $(subdir-ym) $(always)	@: # Linus' kernel sanity checking toolifneq ($(KBUILD_CHECKSRC),0)  ifeq ($(KBUILD_CHECKSRC),2)    quiet_cmd_force_checksrc = CHECK   $<          cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;  else      quiet_cmd_checksrc     = CHECK   $<            cmd_checksrc     = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;  endifendif # Do section mismatch analysis for each module/built-in.oifdef CONFIG_DEBUG_SECTION_MISMATCH  cmd_secanalysis = ; scripts/mod/modpost $@endif # Compile C sources (.c)# --------------------------------------------------------------------------- # Default is built-in, unless we know otherwisemodkern_cflags =                                          \	$(if $(part-of-module),                           \		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))quiet_modtag := $(empty)   $(empty) $(real-objs-m)        : part-of-module := y$(real-objs-m:.o=.i)  : part-of-module := y$(real-objs-m:.o=.s)  : part-of-module := y$(real-objs-m:.o=.lst): part-of-module := y $(real-objs-m)        : quiet_modtag := [M]$(real-objs-m:.o=.i)  : quiet_modtag := [M]$(real-objs-m:.o=.s)  : quiet_modtag := [M]$(real-objs-m:.o=.lst): quiet_modtag := [M] $(obj-m)              : quiet_modtag := [M] # Default for not multi-part modulesmodname = $(basetarget) $(multi-objs-m)         : modname = $(modname-multi)$(multi-objs-m:.o=.i)   : modname = $(modname-multi)$(multi-objs-m:.o=.s)   : modname = $(modname-multi)$(multi-objs-m:.o=.lst) : modname = $(modname-multi)$(multi-objs-y)         : modname = $(modname-multi)$(multi-objs-y:.o=.i)   : modname = $(modname-multi)$(multi-objs-y:.o=.s)   : modname = $(modname-multi)$(multi-objs-y:.o=.lst) : modname = $(modname-multi) quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@cmd_cc_s_c       = $(CC) $(c_flags) $(DISABLE_LTO) -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) cmd_gensymtypes =                                                           \    $(CPP) -D__GENKSYMS__ $(c_flags) $< |                                   \    $(GENKSYMS) $(if $(1), -T $(2))                                         \     $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))             \     $(if $(KBUILD_PRESERVE),-p)                                            \     -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@cmd_cc_symtypes_c =                                                         \    set -e;                                                                 \    $(call cmd_gensymtypes,true,$@) >/dev/null;                             \    test -s $@ || rm -f $@ $(obj)/%.symtypes : $(src)/%.c FORCE	$(call cmd,cc_symtypes_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)  $@ ifndef CONFIG_MODVERSIONScmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< else# When module versioning is enabled the following steps are executed:# o compile a .tmp_<file>.o from <file>.c# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does#   not export symbols, we just rename .tmp_<file>.o to <file>.o and#   are 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 <file>.o from .tmp_<file>.o using the linker to#   replace the unresolved symbols __crc_exported_symbol with#   the actual value of the checksum generated by genksyms cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<cmd_modversions =								\	if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then		\		$(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes))	\		    > $(@D)/.tmp_$(@F:.o=.ver);					\										\		$(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) 			\			-T $(@D)/.tmp_$(@F:.o=.ver);				\		rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver);		\	else									\		mv -f $(@D)/.tmp_$(@F) $@;					\	fi;endif ifdef CONFIG_FTRACE_MCOUNT_RECORDifdef BUILD_C_RECORDMCOUNTifeq ("$(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 = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \	"$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \	"$(if $(CONFIG_64BIT),64,32)" \	"$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \	"$(LD)" "$(NM)" "$(RM)" "$(MV)" \	"$(if $(part-of-module),1,0)" "$(@)";recordmcount_source := $(srctree)/scripts/recordmcount.plendifcmd_record_mcount =						\	if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" =	\	     "$(CC_FLAGS_FTRACE)" ]; then			\		$(sub_cmd_record_mcount)			\	fi;endif ifdef CONFIG_STACK_VALIDATIONifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool objtool_args = checkifndef CONFIG_FRAME_POINTERobjtool_args += --no-fpendif # '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 filecmd_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_VALIDATIONendif # CONFIG_STACK_VALIDATION define rule_cc_o_c	$(call echo-cmd,checksrc) $(cmd_checksrc)			  \	$(call cmd_and_fixdep,cc_o_c)					  \	$(cmd_modversions)						  \	$(cmd_objtool)						          \	$(call echo-cmd,record_mcount) $(cmd_record_mcount)endef define rule_as_o_S	$(call cmd_and_fixdep,as_o_S)					  \	$(cmd_objtool)endef # List module undefined symbols (or empty line if not enabled)ifdef CONFIG_TRIM_UNUSED_KSYMScmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echoelsecmd_undef_syms = echoendif # Built-in and composite module parts$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE	$(call cmd,force_checksrc)	$(call if_changed_rule,cc_o_c) # Single-part modules are special since we need to mark them in $(MODVERDIR) $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE	$(call cmd,force_checksrc)	$(call if_changed_rule,cc_o_c)	@{ echo $(@:.o=.ko); echo $@; \	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.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)# --------------------------------------------------------------------------- modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(real-objs-m)      : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 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 $@ $< $(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE	$(call if_changed_rule,as_o_S) targets += $(real-objs-y) $(real-objs-m) $(lib-y)targets += $(extra-y) $(MAKECMDGOALS) $(always) # Linker scripts preprocessor (.lds.S -> .lds)# ---------------------------------------------------------------------------quiet_cmd_cpp_lds_S = LDS     $@      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(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   $@      cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \				$(subst .h,.c,$@) $(subst .c,.h,$@) .PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h $(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler	$(call cmd,asn1_compiler) # Build the compiled-in targets# --------------------------------------------------------------------------- # To build objects in subdirs, we need to descend into the directories$(sort $(subdir-obj-y)): $(subdir-ym) ; ## Rule to compile a set of .o files into one .o file#ifdef builtin-targetquiet_cmd_link_o_target = LD      $@# If the list of objects to link is empty, just create an empty built-in.ocmd_link_o_target = $(if $(strip $(obj-y)),\		      $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \		      $(cmd_secanalysis),\		      rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@) $(builtin-target): $(obj-y) FORCE	$(call if_changed,link_o_target) targets += $(builtin-target)endif # builtin-target ## Rule to create modules.order file## Create commands to either record .ko file or cat modules.order from# a subdirectorymodorder-cmds =						\	$(foreach m, $(modorder),			\		$(if $(filter %/modules.order, $m),	\			cat $m;, echo kernel/$m;)) $(modorder-target): $(subdir-ym) FORCE	$(Q)(cat /dev/null; $(modorder-cmds)) > $@ ## Rule to compile a set of .o files into one .a file#ifdef lib-targetquiet_cmd_link_l_target = AR      $@cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y) $(lib-target): $(lib-y) FORCE	$(call if_changed,link_l_target) targets += $(lib-target)endif ## Rule to link composite objects##  Composite objects are specified in kbuild makefile as follows:#    <composite-object>-objs := <list of .o files>#  or#    <composite-object>-y    := <list of .o files>#  or#    <composite-object>-m    := <list of .o files>#  The -m syntax only works if <composite object> is a modulelink_multi_deps =                     \$(filter $(addprefix $(obj)/,         \$($(subst $(obj)/,,$(@:.o=-objs)))    \$($(subst $(obj)/,,$(@:.o=-y)))       \$($(subst $(obj)/,,$(@:.o=-m)))), $^) quiet_cmd_link_multi-y = LD      $@cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis) quiet_cmd_link_multi-m = LD [M]  $@cmd_link_multi-m = $(cmd_link_multi-y) $(multi-used-y): FORCE	$(call if_changed,link_multi-y)$(call multi_depend, $(multi-used-y), .o, -objs -y) $(multi-used-m): FORCE	$(call if_changed,link_multi-m)	@{ echo $(@:.o=.ko); echo $(link_multi_deps); \	   $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)$(call multi_depend, $(multi-used-m), .o, -objs -y -m) targets += $(multi-used-y) $(multi-used-m)  # Descending# --------------------------------------------------------------------------- PHONY += $(subdir-ym)$(subdir-ym):	$(Q)$(MAKE) $(build)=$@ # 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. targets := $(wildcard $(sort $(targets)))cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) ifneq ($(cmd_files),)  include $(cmd_files)endif # Declare the contents of the .PHONY variable as phony.  We keep that# information in a variable se we can use it in if_changed and friends. .PHONY: $(PHONY)