| # 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 $(kbuild-file) |
| |
| include scripts/Makefile.lib |
| |
| # Do not include host rules unless needed |
| ifneq ($(hostprogs)$(hostcxxlibs-y)$(hostcxxlibs-m),) |
| include scripts/Makefile.host |
| endif |
| |
| # Do not include userprogs rules unless needed. |
| 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), $(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) |
| |
| # 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 |
| |
| 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 |
| |
| ifdef CONFIG_FTRACE_MCOUNT_RECORD |
| ifndef CC_USING_RECORD_MCOUNT |
| # 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)), \ |
| $(sub_cmd_record_mcount)) |
| endif # CC_USING_RECORD_MCOUNT |
| endif # CONFIG_FTRACE_MCOUNT_RECORD |
| |
| ifdef CONFIG_STACK_VALIDATION |
| ifneq ($(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 |
| endif |
| |
| define rule_cc_o_c |
| $(call cmd,checksrc) |
| $(call cmd_and_fixdep,cc_o_c) |
| $(call cmd,gen_ksymdeps) |
| $(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 |
| |
| # List module undefined symbols (or empty line if not enabled) |
| ifdef CONFIG_TRIM_UNUSED_KSYMS |
| cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | xargs echo |
| else |
| cmd_undef_syms = echo |
| endif |
| |
| # Built-in and composite module parts |
| $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE |
| $(call cmd,force_checksrc) |
| $(call if_changed_rule,cc_o_c) |
| |
| cmd_mod = { \ |
| echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \ |
| $(cmd_undef_syms); \ |
| } > $@ |
| |
| $(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)/% ; |
| |
| # |
| # 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) |
| |
| $(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) |
| |
| # 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. |
| quiet_cmd_link_multi-m = LD [M] $@ |
| cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) |
| |
| $(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) |
| |
| ifdef building_out_of_srctree |
| # Create directories for object files if they do not exist |
| obj-dirs := $(sort $(obj) $(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 |
| endif |
| |
| .PHONY: $(PHONY) |
