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
36 # Read auto.conf if it exists, otherwise ignore
37 -include include/config/auto.conf
39 include scripts/Kbuild.include
41 # The filename Kbuild has precedence over Makefile
42 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44 include $(kbuild-file)
46 include scripts/Makefile.lib
48 # Do not include hostprogs rules unless needed.
49 # $(sort ...) is used here to remove duplicated words and excessive spaces.
50 hostprogs := $(sort $(hostprogs))
52 include scripts/Makefile.host
55 # Do not include userprogs rules unless needed.
56 # $(sort ...) is used here to remove duplicated words and excessive spaces.
57 userprogs := $(sort $(userprogs))
59 include scripts/Makefile.userprogs
63 $(warning kbuild: Makefile.build is included improperly)
66 ifeq ($(need-modorder),)
68 $(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
69 $(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
73 # ===========================================================================
75 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
76 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
77 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
79 targets-for-builtin := $(extra-y)
81 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
82 targets-for-builtin += $(obj)/lib.a
86 targets-for-builtin += $(obj)/built-in.a
89 targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
92 targets-for-modules += $(obj)/modules.order
95 targets += $(targets-for-builtin) $(targets-for-modules)
97 # Linus' kernel sanity checking tool
98 ifeq ($(KBUILD_CHECKSRC),1)
99 quiet_cmd_checksrc = CHECK $<
100 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
101 else ifeq ($(KBUILD_CHECKSRC),2)
102 quiet_cmd_force_checksrc = CHECK $<
103 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
106 ifneq ($(KBUILD_EXTRA_WARN),)
107 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
110 # Compile C sources (.c)
111 # ---------------------------------------------------------------------------
113 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
114 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
116 $(obj)/%.s: $(src)/%.c FORCE
117 $(call if_changed_dep,cc_s_c)
119 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
120 cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
122 $(obj)/%.i: $(src)/%.c FORCE
123 $(call if_changed_dep,cpp_i_c)
125 # These mirror gensymtypes_S and co below, keep them in synch.
126 cmd_gensymtypes_c = \
127 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
128 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
129 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
130 $(if $(KBUILD_PRESERVE),-p) \
131 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
133 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
134 cmd_cc_symtypes_c = \
135 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
136 test -s $@ || rm -f $@
138 $(obj)/%.symtypes : $(src)/%.c FORCE
139 $(call cmd,cc_symtypes_c)
142 # Generate .ll files from .c
143 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
144 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
146 $(obj)/%.ll: $(src)/%.c FORCE
147 $(call if_changed_dep,cc_ll_c)
150 # The C file is compiled and updated dependency information is generated.
151 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
153 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
154 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
156 ifdef CONFIG_MODVERSIONS
157 # When module versioning is enabled the following steps are executed:
158 # o compile a <file>.o from <file>.c
159 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
160 # not export symbols, it's done.
161 # o otherwise, we calculate symbol versions using the good old
162 # genksyms on the preprocessed source and postprocess them in a way
163 # that they are usable as a linker script
164 # o generate .tmp_<file>.o from <file>.o using the linker to
165 # replace the unresolved symbols __crc_exported_symbol with
166 # the actual value of the checksum generated by genksyms
167 # o remove .tmp_<file>.o to <file>.o
169 ifdef CONFIG_LTO_CLANG
170 # Generate .o.symversions files for each .o with exported symbols, and link these
171 # to the kernel and/or modules at the end.
172 cmd_modversions_c = \
173 if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
174 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
178 cmd_modversions_c = \
179 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
180 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
181 > $(@D)/.tmp_$(@F:.o=.ver); \
183 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
184 -T $(@D)/.tmp_$(@F:.o=.ver); \
185 mv -f $(@D)/.tmp_$(@F) $@; \
186 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
191 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
192 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
193 ifdef BUILD_C_RECORDMCOUNT
194 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
195 RECORDMCOUNT_FLAGS = -w
197 # Due to recursion, we must skip empty.o.
198 # The empty.o file is created in the make process in order to determine
199 # the target endianness and word size. It is made before all other C
200 # files, including recordmcount.
201 sub_cmd_record_mcount = \
202 if [ $(@) != "scripts/mod/empty.o" ]; then \
203 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
205 recordmcount_source := $(srctree)/scripts/recordmcount.c \
206 $(srctree)/scripts/recordmcount.h
208 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
209 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
210 "$(if $(CONFIG_64BIT),64,32)" \
211 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
212 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
213 "$(if $(part-of-module),1,0)" "$(@)";
214 recordmcount_source := $(srctree)/scripts/recordmcount.pl
215 endif # BUILD_C_RECORDMCOUNT
216 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
217 $(sub_cmd_record_mcount))
218 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
220 ifdef CONFIG_STACK_VALIDATION
221 ifneq ($(SKIP_STACK_VALIDATION),1)
223 __objtool_obj := $(objtree)/tools/objtool/objtool
225 objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
227 objtool_args += $(if $(part-of-module), --module,)
229 ifndef CONFIG_FRAME_POINTER
230 objtool_args += --no-fp
232 ifdef CONFIG_GCOV_KERNEL
233 objtool_args += --no-unreachable
235 ifdef CONFIG_RETPOLINE
236 objtool_args += --retpoline
238 ifdef CONFIG_X86_SMAP
239 objtool_args += --uaccess
241 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
242 objtool_args += --mcount
245 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
246 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
247 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
248 cmd_objtool = $(if $(patsubst y%,, \
249 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
250 $(__objtool_obj) $(objtool_args) $@)
251 objtool_obj = $(if $(patsubst y%,, \
252 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
255 endif # SKIP_STACK_VALIDATION
256 endif # CONFIG_STACK_VALIDATION
258 # Rebuild all objects when objtool changes, or is enabled/disabled.
259 objtool_dep = $(objtool_obj) \
260 $(wildcard include/config/orc/unwinder.h \
261 include/config/stack/validation.h)
263 ifdef CONFIG_TRIM_UNUSED_KSYMS
265 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
267 # List module undefined symbols
268 undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
272 $(call cmd_and_fixdep,cc_o_c)
273 $(call cmd,gen_ksymdeps)
277 $(call cmd,modversions_c)
278 $(call cmd,record_mcount)
282 $(call cmd_and_fixdep,as_o_S)
283 $(call cmd,gen_ksymdeps)
285 $(call cmd,modversions_S)
288 # Built-in and composite module parts
289 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
290 $(call if_changed_rule,cc_o_c)
291 $(call cmd,force_checksrc)
294 echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
295 $(undefined_syms) echo; \
298 $(obj)/%.mod: $(obj)/%.o FORCE
299 $(call if_changed,mod)
301 quiet_cmd_cc_lst_c = MKLST $@
302 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
303 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
304 System.map $(OBJDUMP) > $@
306 $(obj)/%.lst: $(src)/%.c FORCE
307 $(call if_changed_dep,cc_lst_c)
309 # Compile assembler sources (.S)
310 # ---------------------------------------------------------------------------
312 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
313 # or a file that it includes, in order to get versioned symbols. We build a
314 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
315 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
317 # This is convoluted. The .S file must first be preprocessed to run guards and
318 # expand names, then the resulting exports must be constructed into plain
319 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
320 # to make the genksyms input.
322 # These mirror gensymtypes_c and co above, keep them in synch.
323 cmd_gensymtypes_S = \
324 { echo "\#include <linux/kernel.h>" ; \
325 echo "\#include <asm/asm-prototypes.h>" ; \
326 $(CPP) $(a_flags) $< | \
327 grep "\<___EXPORT_SYMBOL\>" | \
328 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
329 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
330 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
331 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
332 $(if $(KBUILD_PRESERVE),-p) \
333 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
335 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
336 cmd_cc_symtypes_S = \
337 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
338 test -s $@ || rm -f $@
340 $(obj)/%.symtypes : $(src)/%.S FORCE
341 $(call cmd,cc_symtypes_S)
344 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
345 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
347 $(obj)/%.s: $(src)/%.S FORCE
348 $(call if_changed_dep,cpp_s_S)
350 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
351 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
353 ifdef CONFIG_ASM_MODVERSIONS
355 # versioning matches the C process described above, with difference that
356 # we parse asm-prototypes.h C header to get function definitions.
358 cmd_modversions_S = \
359 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
360 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
361 > $(@D)/.tmp_$(@F:.o=.ver); \
363 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
364 -T $(@D)/.tmp_$(@F:.o=.ver); \
365 mv -f $(@D)/.tmp_$(@F) $@; \
366 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
370 $(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
371 $(call if_changed_rule,as_o_S)
373 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
374 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
375 targets += $(lib-y) $(always-y) $(MAKECMDGOALS)
377 # Linker scripts preprocessor (.lds.S -> .lds)
378 # ---------------------------------------------------------------------------
379 quiet_cmd_cpp_lds_S = LDS $@
380 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
381 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
383 $(obj)/%.lds: $(src)/%.lds.S FORCE
384 $(call if_changed_dep,cpp_lds_S)
387 # ---------------------------------------------------------------------------
388 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
389 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
390 $(basename $@).c $(basename $@).h
392 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
393 $(call cmd,asn1_compiler)
395 # Build the compiled-in targets
396 # ---------------------------------------------------------------------------
398 # To build objects in subdirs, we need to descend into the directories
399 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
400 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
402 # combine symversions for later processing
403 quiet_cmd_update_lto_symversions = SYMVER $@
404 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
405 cmd_update_lto_symversions = \
406 rm -f $@.symversions \
407 $(foreach n, $(filter-out FORCE,$^), \
408 $(if $(wildcard $(n).symversions), \
409 ; cat $(n).symversions >> $@.symversions))
411 cmd_update_lto_symversions = echo >/dev/null
415 # Rule to compile a set of .o files into one .a file (without symbol table)
418 quiet_cmd_ar_builtin = AR $@
419 cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
421 quiet_cmd_ar_and_symver = AR $@
422 cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
424 $(obj)/built-in.a: $(real-obj-y) FORCE
425 $(call if_changed,ar_and_symver)
428 # Rule to create modules.order file
430 # Create commands to either record .ko file or cat modules.order from
432 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
433 # modules.order unless contained modules are updated.
435 cmd_modules_order = { $(foreach m, $(real-prereqs), \
436 $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
437 | $(AWK) '!x[$$0]++' - > $@
439 $(obj)/modules.order: $(obj-m) FORCE
440 $(call if_changed,modules_order)
443 # Rule to compile a set of .o files into one .a file (with symbol table)
445 quiet_cmd_ar_lib = AR $@
446 cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
448 $(obj)/lib.a: $(lib-y) FORCE
449 $(call if_changed,ar_lib)
452 # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
453 # module is turned into a multi object module, $^ will contain header file
454 # dependencies recorded in the .*.cmd file.
455 ifdef CONFIG_LTO_CLANG
456 quiet_cmd_link_multi-m = AR [M] $@
458 $(cmd_update_lto_symversions); \
460 $(AR) cDPrsT $@ $(filter %.o,$^)
462 quiet_cmd_link_multi-m = LD [M] $@
463 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
466 $(multi-used-m): FORCE
467 $(call if_changed,link_multi-m)
468 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
470 targets += $(multi-used-m)
471 targets := $(filter-out $(PHONY), $(targets))
473 # Add intermediate targets:
474 # When building objects with specific suffix patterns, add intermediate
475 # targets that the final targets are derived from.
476 intermediate_targets = $(foreach sfx, $(2), \
477 $(patsubst %$(strip $(1)),%$(sfx), \
478 $(filter %$(strip $(1)), $(targets))))
479 # %.asn1.o <- %.asn1.[ch] <- %.asn1
480 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
481 # %.lex.o <- %.lex.c <- %.l
482 # %.tab.o <- %.tab.[ch] <- %.y
483 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
484 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
485 $(call intermediate_targets, .lex.o, .lex.c) \
486 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
489 # ---------------------------------------------------------------------------
493 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
495 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
496 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
498 # Handle single targets without any rule: show "Nothing to be done for ..." or
499 # "No rule to make target ..." depending on whether the target exists.
500 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
501 $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
503 single-subdirs := $(foreach d, $(subdir-ym), \
504 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
506 __build: $(curdir-single) $(single-subdirs)
507 ifneq ($(unknown-single),)
508 $(Q)$(MAKE) -f /dev/null $(unknown-single)
512 ifeq ($(curdir-single),)
513 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
516 targets += $(curdir-single)
521 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
522 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
523 $(subdir-ym) $(always-y)
529 # ---------------------------------------------------------------------------
531 PHONY += $(subdir-ym)
533 $(Q)$(MAKE) $(build)=$@ \
534 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
535 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
536 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
538 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
539 # ---------------------------------------------------------------------------
545 # Read all saved command lines and dependencies for the $(targets) we
546 # may be building above, using $(if_changed{,_dep}). As an
547 # optimization, we don't need to read them if the target does not
548 # exist, we will rebuild anyway in that case.
550 existing-targets := $(wildcard $(sort $(targets)))
552 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
554 # Create directories for object files if they do not exist
555 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
556 # If targets exist, their directories apparently exist. Skip mkdir.
557 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
558 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
560 $(shell mkdir -p $(obj-dirs))