# ========================================================================== # 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 := 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 change save-cflags := $(CFLAGS) # 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 $(kbuild-file) # If the save-* variables changed error out ifeq ($(KBUILD_NOPEDANTIC),) ifneq ("$(save-cflags)","$(CFLAGS)") $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y) endif endif # # make W=... settings # # W=1 - warnings that may be relevant and does not occur too often # W=2 - warnings that occur quite often but may still be relevant # W=3 - the more obscure warnings, can most likely be ignored # # $(call cc-option, -W...) handles gcc -W.. options which # are not supported by all versions of the compiler ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS warning- := $(empty) warning-1 := -Wextra -Wunused -Wno-unused-parameter warning-1 += -Wmissing-declarations warning-1 += -Wmissing-format-attribute warning-1 += -Wmissing-prototypes warning-1 += -Wold-style-definition warning-1 += $(call cc-option, -Wmissing-include-dirs) warning-1 += $(call cc-option, -Wunused-but-set-variable) warning-1 += $(call cc-disable-warning, missing-field-initializers) warning-2 := -Waggregate-return warning-2 += -Wcast-align warning-2 += -Wdisabled-optimization warning-2 += -Wnested-externs warning-2 += -Wshadow warning-2 += $(call cc-option, -Wlogical-op) warning-2 += $(call cc-option, -Wmissing-field-initializers) warning-3 := -Wbad-function-cast warning-3 += -Wcast-qual warning-3 += -Wconversion warning-3 += -Wpacked warning-3 += -Wpadded warning-3 += -Wpointer-arith warning-3 += -Wredundant-decls warning-3 += -Wswitch-default warning-3 += $(call cc-option, -Wpacked-bitfield-compat) warning-3 += $(call cc-option, -Wvla) warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS))) ifeq ("$(strip $(warning))","") $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown) endif KBUILD_CFLAGS += $(warning) endif include scripts/Makefile.lib ifdef host-progs ifneq ($(hostprogs-y),$(host-progs)) $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!) hostprogs-y += $(host-progs) endif endif # Do not include host rules unless needed ifneq ($(hostprogs-y)$(hostprogs-m),) include scripts/Makefile.host endif ifneq ($(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-n) $(lib-)),) lib-target := $(obj)/lib.a endif ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),) builtin-target := $(obj)/built-in.o endif 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) $(always) @: # Linus' kernel sanity checking tool ifneq ($(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) $< ; endif endif # Do section mismatch analysis for each module/built-in.o ifdef CONFIG_DEBUG_SECTION_MISMATCH cmd_secanalysis = ; scripts/mod/modpost $@ endif # Compile C sources (.c) # --------------------------------------------------------------------------- # Default is built-in, unless we know otherwise modkern_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 modules modname = $(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) -fverbose-asm -S -o $@ $< $(obj)/%.s: $(src)/%.c FORCE $(call if_changed_dep,cc_s_c) quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@ cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $< $(obj)/%.i: $(src)/%.c FORCE $(call if_changed_dep,cc_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_MODVERSIONS cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< else # When module versioning is enabled the following steps are executed: # o compile a .tmp_.o from .c # o if .tmp_.o doesn't contain a __ksymtab version, i.e. does # not export symbols, we just rename .tmp_.o to .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 .o from .tmp_.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) $@; \ fi; endif ifdef CONFIG_FTRACE_MCOUNT_RECORD ifdef BUILD_C_RECORDMCOUNT ifeq ("$(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 = 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 := $(srctree)/scripts/recordmcount.pl endif cmd_record_mcount = \ if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \ $(sub_cmd_record_mcount) \ fi; endif define rule_cc_o_c $(call echo-cmd,checksrc) $(cmd_checksrc) \ $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \ $(cmd_modversions) \ $(call echo-cmd,record_mcount) \ $(cmd_record_mcount) \ scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \ $(dot-target).tmp; \ rm -f $(depfile); \ mv -f $(dot-target).tmp $(dot-target).cmd endef # Built-in and composite module parts $(obj)/%.o: $(src)/%.c $(recordmcount_source) 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) FORCE $(call cmd,force_checksrc) $(call if_changed_rule,cc_o_c) @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@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_as_s_S = CPP $(quiet_modtag) $@ cmd_as_s_S = $(CPP) $(a_flags) -o $@ $< $(obj)/%.s: $(src)/%.S FORCE $(call if_changed_dep,as_s_S) quiet_cmd_as_o_S = AS $(quiet_modtag) $@ cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(obj)/%.o: $(src)/%.S FORCE $(call if_changed_dep,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-target quiet_cmd_link_o_target = LD $@ # If the list of objects to link is empty, just create an empty built-in.o cmd_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 subdirectory modorder-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-target quiet_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: # -objs := # or # -y := link_multi_deps = \ $(filter $(addprefix $(obj)/, \ $($(subst $(obj)/,,$(@:.o=-objs))) \ $($(subst $(obj)/,,$(@:.o=-y)))), $^) 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) # We would rather have a list of rules like # foo.o: $(foo-objs) # but that's not so easy, so we rather make all composite objects depend # on the set of all their parts $(multi-used-y) : %.o: $(multi-objs-y) FORCE $(call if_changed,link_multi-y) $(multi-used-m) : %.o: $(multi-objs-m) FORCE $(call if_changed,link_multi-m) @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod) 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)