1 # SPDX-License-Identifier: GPL-2.0
2 # ==========================================================================
4 # ==========================================================================
11 # Init all relevant variables used in kbuild files so
12 # 1) they have correct type
13 # 2) they do not inherit any value from the environment
34 # Read auto.conf if it exists, otherwise ignore
35 -include include/config/auto.conf
37 include scripts/Kbuild.include
39 # The filename Kbuild has precedence over Makefile
40 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
41 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
42 include $(kbuild-file)
44 include scripts/Makefile.lib
46 # Do not include host rules unless needed
47 ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
48 include scripts/Makefile.host
52 $(warning kbuild: Makefile.build is included improperly)
55 # ===========================================================================
57 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
58 lib-target := $(obj)/lib.a
59 real-obj-y += $(obj)/lib-ksyms.o
62 ifneq ($(strip $(real-obj-y) $(need-builtin)),)
63 builtin-target := $(obj)/built-in.a
66 modorder-target := $(obj)/modules.order
68 # We keep a list of all modules in $(MODVERDIR)
70 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
71 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
72 $(subdir-ym) $(always)
75 # Linus' kernel sanity checking tool
76 ifeq ($(KBUILD_CHECKSRC),1)
77 quiet_cmd_checksrc = CHECK $<
78 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
79 else ifeq ($(KBUILD_CHECKSRC),2)
80 quiet_cmd_force_checksrc = CHECK $<
81 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
84 ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
85 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ;
88 # Do section mismatch analysis for each module/built-in.a
89 ifdef CONFIG_DEBUG_SECTION_MISMATCH
90 cmd_secanalysis = ; scripts/mod/modpost $@
93 # Compile C sources (.c)
94 # ---------------------------------------------------------------------------
96 # Default is built-in, unless we know otherwise
98 $(if $(part-of-module), \
99 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
100 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
101 quiet_modtag := $(empty) $(empty)
103 $(real-obj-m) : part-of-module := y
104 $(real-obj-m:.o=.i) : part-of-module := y
105 $(real-obj-m:.o=.s) : part-of-module := y
106 $(real-obj-m:.o=.lst): part-of-module := y
108 $(real-obj-m) : quiet_modtag := [M]
109 $(real-obj-m:.o=.i) : quiet_modtag := [M]
110 $(real-obj-m:.o=.s) : quiet_modtag := [M]
111 $(real-obj-m:.o=.lst): quiet_modtag := [M]
113 $(obj-m) : quiet_modtag := [M]
115 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
116 cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
118 $(obj)/%.s: $(src)/%.c FORCE
119 $(call if_changed_dep,cc_s_c)
121 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
122 cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
124 $(obj)/%.i: $(src)/%.c FORCE
125 $(call if_changed_dep,cpp_i_c)
127 # These mirror gensymtypes_S and co below, keep them in synch.
128 cmd_gensymtypes_c = \
129 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
130 $(GENKSYMS) $(if $(1), -T $(2)) \
131 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
132 $(if $(KBUILD_PRESERVE),-p) \
133 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
135 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
136 cmd_cc_symtypes_c = \
138 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
139 test -s $@ || rm -f $@
141 $(obj)/%.symtypes : $(src)/%.c FORCE
142 $(call cmd,cc_symtypes_c)
145 # Generate .ll files from .c
146 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
147 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
149 $(obj)/%.ll: $(src)/%.c FORCE
150 $(call if_changed_dep,cc_ll_c)
153 # The C file is compiled and updated dependency information is generated.
154 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
156 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
157 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
159 ifdef CONFIG_MODVERSIONS
160 # When module versioning is enabled the following steps are executed:
161 # o compile a <file>.o from <file>.c
162 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
163 # not export symbols, it's done.
164 # o otherwise, we calculate symbol versions using the good old
165 # genksyms on the preprocessed source and postprocess them in a way
166 # that they are usable as a linker script
167 # o generate .tmp_<file>.o from <file>.o using the linker to
168 # replace the unresolved symbols __crc_exported_symbol with
169 # the actual value of the checksum generated by genksyms
170 # o remove .tmp_<file>.o to <file>.o
172 cmd_modversions_c = \
173 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
174 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
175 > $(@D)/.tmp_$(@F:.o=.ver); \
177 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
178 -T $(@D)/.tmp_$(@F:.o=.ver); \
179 mv -f $(@D)/.tmp_$(@F) $@; \
180 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
184 ifdef CONFIG_FTRACE_MCOUNT_RECORD
185 ifndef CC_USING_RECORD_MCOUNT
186 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
187 ifdef BUILD_C_RECORDMCOUNT
188 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
189 RECORDMCOUNT_FLAGS = -w
191 # Due to recursion, we must skip empty.o.
192 # The empty.o file is created in the make process in order to determine
193 # the target endianness and word size. It is made before all other C
194 # files, including recordmcount.
195 sub_cmd_record_mcount = \
196 if [ $(@) != "scripts/mod/empty.o" ]; then \
197 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
199 recordmcount_source := $(srctree)/scripts/recordmcount.c \
200 $(srctree)/scripts/recordmcount.h
202 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
203 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
204 "$(if $(CONFIG_64BIT),64,32)" \
205 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
206 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
207 "$(if $(part-of-module),1,0)" "$(@)";
208 recordmcount_source := $(srctree)/scripts/recordmcount.pl
209 endif # BUILD_C_RECORDMCOUNT
210 cmd_record_mcount = \
211 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
212 "$(CC_FLAGS_FTRACE)" ]; then \
213 $(sub_cmd_record_mcount) \
215 endif # CC_USING_RECORD_MCOUNT
216 endif # CONFIG_FTRACE_MCOUNT_RECORD
218 ifdef CONFIG_STACK_VALIDATION
219 ifneq ($(SKIP_STACK_VALIDATION),1)
221 __objtool_obj := $(objtree)/tools/objtool/objtool
223 objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
225 objtool_args += $(if $(part-of-module), --module,)
227 ifndef CONFIG_FRAME_POINTER
228 objtool_args += --no-fp
230 ifdef CONFIG_GCOV_KERNEL
231 objtool_args += --no-unreachable
233 ifdef CONFIG_RETPOLINE
234 ifneq ($(RETPOLINE_CFLAGS),)
235 objtool_args += --retpoline
239 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
240 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
241 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
242 cmd_objtool = $(if $(patsubst y%,, \
243 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
244 $(__objtool_obj) $(objtool_args) $@;)
245 objtool_obj = $(if $(patsubst y%,, \
246 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
249 endif # SKIP_STACK_VALIDATION
250 endif # CONFIG_STACK_VALIDATION
252 # Rebuild all objects when objtool changes, or is enabled/disabled.
253 objtool_dep = $(objtool_obj) \
254 $(wildcard include/config/orc/unwinder.h \
255 include/config/stack/validation.h)
257 ifdef CONFIG_TRIM_UNUSED_KSYMS
259 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd;
263 $(call echo-cmd,checksrc) $(cmd_checksrc) \
264 $(call cmd_and_fixdep,cc_o_c) \
265 $(cmd_gen_ksymdeps) \
267 $(call echo-cmd,objtool) $(cmd_objtool) \
268 $(cmd_modversions_c) \
269 $(call echo-cmd,record_mcount) $(cmd_record_mcount)
273 $(call cmd_and_fixdep,as_o_S) \
274 $(cmd_gen_ksymdeps) \
275 $(call echo-cmd,objtool) $(cmd_objtool) \
279 # List module undefined symbols (or empty line if not enabled)
280 ifdef CONFIG_TRIM_UNUSED_KSYMS
281 cmd_undef_syms = $(NM) $@ | sed -n 's/^ *U //p' | xargs echo
283 cmd_undef_syms = echo
286 # Built-in and composite module parts
287 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
288 $(call cmd,force_checksrc)
289 $(call if_changed_rule,cc_o_c)
291 # Single-part modules are special since we need to mark them in $(MODVERDIR)
293 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
294 $(call cmd,force_checksrc)
295 $(call if_changed_rule,cc_o_c)
296 @{ echo $(@:.o=.ko); echo $@; \
297 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
299 quiet_cmd_cc_lst_c = MKLST $@
300 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
301 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
302 System.map $(OBJDUMP) > $@
304 $(obj)/%.lst: $(src)/%.c FORCE
305 $(call if_changed_dep,cc_lst_c)
307 # Compile assembler sources (.S)
308 # ---------------------------------------------------------------------------
310 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
312 $(real-obj-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
313 $(real-obj-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
315 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
316 # or a file that it includes, in order to get versioned symbols. We build a
317 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
318 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
320 # This is convoluted. The .S file must first be preprocessed to run guards and
321 # expand names, then the resulting exports must be constructed into plain
322 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
323 # to make the genksyms input.
325 # These mirror gensymtypes_c and co above, keep them in synch.
326 cmd_gensymtypes_S = \
327 (echo "\#include <linux/kernel.h>" ; \
328 echo "\#include <asm/asm-prototypes.h>" ; \
329 $(CPP) $(a_flags) $< | \
330 grep "\<___EXPORT_SYMBOL\>" | \
331 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
332 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
333 $(GENKSYMS) $(if $(1), -T $(2)) \
334 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
335 $(if $(KBUILD_PRESERVE),-p) \
336 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
338 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
339 cmd_cc_symtypes_S = \
341 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
342 test -s $@ || rm -f $@
344 $(obj)/%.symtypes : $(src)/%.S FORCE
345 $(call cmd,cc_symtypes_S)
348 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
349 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
351 $(obj)/%.s: $(src)/%.S FORCE
352 $(call if_changed_dep,cpp_s_S)
354 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
355 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
357 ifdef CONFIG_MODVERSIONS
359 ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
361 ifneq ($(ASM_PROTOTYPES),)
363 # versioning matches the C process described above, with difference that
364 # we parse asm-prototypes.h C header to get function definitions.
366 cmd_modversions_S = \
367 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
368 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
369 > $(@D)/.tmp_$(@F:.o=.ver); \
371 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
372 -T $(@D)/.tmp_$(@F:.o=.ver); \
373 mv -f $(@D)/.tmp_$(@F) $@; \
374 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
379 $(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
380 $(call if_changed_rule,as_o_S)
382 targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
383 targets += $(extra-y) $(MAKECMDGOALS) $(always)
385 # Linker scripts preprocessor (.lds.S -> .lds)
386 # ---------------------------------------------------------------------------
387 quiet_cmd_cpp_lds_S = LDS $@
388 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
389 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
391 $(obj)/%.lds: $(src)/%.lds.S FORCE
392 $(call if_changed_dep,cpp_lds_S)
395 # ---------------------------------------------------------------------------
396 quiet_cmd_asn1_compiler = ASN.1 $@
397 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
398 $(subst .h,.c,$@) $(subst .c,.h,$@)
400 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
401 $(call cmd,asn1_compiler)
403 # Build the compiled-in targets
404 # ---------------------------------------------------------------------------
406 # To build objects in subdirs, we need to descend into the directories
407 $(sort $(subdir-obj-y)): $(subdir-ym) ;
410 # Rule to compile a set of .o files into one .o file
414 # built-in.a archives are made with no symbol table or index which
415 # makes them small and fast, but unable to be used by the linker.
416 # scripts/link-vmlinux.sh builds an aggregate built-in.a with a symbol
418 quiet_cmd_ar_builtin = AR $@
419 cmd_ar_builtin = rm -f $@; \
420 $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(filter $(real-obj-y), $^)
422 $(builtin-target): $(real-obj-y) FORCE
423 $(call if_changed,ar_builtin)
425 targets += $(builtin-target)
426 endif # builtin-target
429 # Rule to create modules.order file
431 # Create commands to either record .ko file or cat modules.order from
434 $(foreach m, $(modorder), \
435 $(if $(filter %/modules.order, $m), \
436 cat $m;, echo kernel/$m;))
438 $(modorder-target): $(subdir-ym) FORCE
439 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
442 # Rule to compile a set of .o files into one .a file
445 quiet_cmd_link_l_target = AR $@
447 # lib target archives do get a symbol table and index
448 cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
450 $(lib-target): $(lib-y) FORCE
451 $(call if_changed,link_l_target)
453 targets += $(lib-target)
455 dummy-object = $(obj)/.lib_exports.o
456 ksyms-lds = $(dot-target).lds
458 quiet_cmd_export_list = EXPORTS $@
459 cmd_export_list = $(OBJDUMP) -h $< | \
460 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/EXTERN(\1)/p' >$(ksyms-lds);\
461 rm -f $(dummy-object);\
462 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
463 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
464 rm $(dummy-object) $(ksyms-lds)
466 $(obj)/lib-ksyms.o: $(lib-target) FORCE
467 $(call if_changed,export_list)
469 targets += $(obj)/lib-ksyms.o
473 quiet_cmd_link_multi-m = LD [M] $@
474 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^) $(cmd_secanalysis)
476 $(multi-used-m): FORCE
477 $(call if_changed,link_multi-m)
478 @{ echo $(@:.o=.ko); echo $(filter %.o,$^); \
479 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
480 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
482 targets += $(multi-used-m)
483 targets := $(filter-out $(PHONY), $(targets))
485 # Add intermediate targets:
486 # When building objects with specific suffix patterns, add intermediate
487 # targets that the final targets are derived from.
488 intermediate_targets = $(foreach sfx, $(2), \
489 $(patsubst %$(strip $(1)),%$(sfx), \
490 $(filter %$(strip $(1)), $(targets))))
491 # %.asn1.o <- %.asn1.[ch] <- %.asn1
492 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
493 # %.lex.o <- %.lex.c <- %.l
494 # %.tab.o <- %.tab.[ch] <- %.y
495 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
496 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
497 $(call intermediate_targets, .lex.o, .lex.c) \
498 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
501 # ---------------------------------------------------------------------------
503 PHONY += $(subdir-ym)
505 $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
507 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
508 # ---------------------------------------------------------------------------
514 # Read all saved command lines and dependencies for the $(targets) we
515 # may be building above, using $(if_changed{,_dep}). As an
516 # optimization, we don't need to read them if the target does not
517 # exist, we will rebuild anyway in that case.
519 existing-targets := $(wildcard $(sort $(targets)))
521 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
523 ifneq ($(KBUILD_SRC),)
524 # Create directories for object files if they do not exist
525 obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
526 # If targets exist, their directories apparently exist. Skip mkdir.
527 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
528 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
530 $(shell mkdir -p $(obj-dirs))
534 # Some files contained in $(targets) are intermediate artifacts.
535 # We never want them to be removed automatically.
536 .SECONDARY: $(targets)