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
35 # Read auto.conf if it exists, otherwise ignore
36 -include include/config/auto.conf
38 include $(srctree)/scripts/Kbuild.include
39 include $(srctree)/scripts/Makefile.compiler
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 $(srctree)/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 $(srctree)/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 $(srctree)/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)))
91 ifdef CONFIG_LTO_CLANG
92 targets-for-modules += $(patsubst %.o, %.lto.o, $(filter %.o, $(obj-m)))
96 targets-for-modules += $(obj)/modules.order
99 targets += $(targets-for-builtin) $(targets-for-modules)
101 # Linus' kernel sanity checking tool
102 ifeq ($(KBUILD_CHECKSRC),1)
103 quiet_cmd_checksrc = CHECK $<
104 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
105 else ifeq ($(KBUILD_CHECKSRC),2)
106 quiet_cmd_force_checksrc = CHECK $<
107 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
110 ifneq ($(KBUILD_EXTRA_WARN),)
111 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
114 # Compile C sources (.c)
115 # ---------------------------------------------------------------------------
117 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
118 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
120 $(obj)/%.s: $(src)/%.c FORCE
121 $(call if_changed_dep,cc_s_c)
123 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
124 cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
126 $(obj)/%.i: $(src)/%.c FORCE
127 $(call if_changed_dep,cpp_i_c)
129 # These mirror gensymtypes_S and co below, keep them in synch.
130 cmd_gensymtypes_c = \
131 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
132 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
133 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
134 $(if $(KBUILD_PRESERVE),-p) \
135 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
137 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
138 cmd_cc_symtypes_c = \
139 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
140 test -s $@ || rm -f $@
142 $(obj)/%.symtypes : $(src)/%.c FORCE
143 $(call cmd,cc_symtypes_c)
146 # Generate .ll files from .c
147 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
148 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
150 $(obj)/%.ll: $(src)/%.c FORCE
151 $(call if_changed_dep,cc_ll_c)
154 # The C file is compiled and updated dependency information is generated.
155 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
157 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
158 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
160 ifdef CONFIG_MODVERSIONS
161 # When module versioning is enabled the following steps are executed:
162 # o compile a <file>.o from <file>.c
163 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
164 # not export symbols, it's done.
165 # o otherwise, we calculate symbol versions using the good old
166 # genksyms on the preprocessed source and postprocess them in a way
167 # that they are usable as a linker script
168 # o generate .tmp_<file>.o from <file>.o using the linker to
169 # replace the unresolved symbols __crc_exported_symbol with
170 # the actual value of the checksum generated by genksyms
171 # o remove .tmp_<file>.o to <file>.o
173 ifdef CONFIG_LTO_CLANG
174 # Generate .o.symversions files for each .o with exported symbols, and link these
175 # to the kernel and/or modules at the end.
176 cmd_modversions_c = \
177 if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
178 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
182 cmd_modversions_c = \
183 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
184 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
185 > $(@D)/.tmp_$(@F:.o=.ver); \
187 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
188 -T $(@D)/.tmp_$(@F:.o=.ver); \
189 mv -f $(@D)/.tmp_$(@F) $@; \
190 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
195 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
196 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
197 ifdef BUILD_C_RECORDMCOUNT
198 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
199 RECORDMCOUNT_FLAGS = -w
201 # Due to recursion, we must skip empty.o.
202 # The empty.o file is created in the make process in order to determine
203 # the target endianness and word size. It is made before all other C
204 # files, including recordmcount.
205 sub_cmd_record_mcount = \
206 if [ $(@) != "scripts/mod/empty.o" ]; then \
207 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
209 recordmcount_source := $(srctree)/scripts/recordmcount.c \
210 $(srctree)/scripts/recordmcount.h
212 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
213 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
214 "$(if $(CONFIG_64BIT),64,32)" \
215 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
216 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
217 "$(if $(part-of-module),1,0)" "$(@)";
218 recordmcount_source := $(srctree)/scripts/recordmcount.pl
219 endif # BUILD_C_RECORDMCOUNT
220 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
221 $(sub_cmd_record_mcount))
222 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
224 ifdef CONFIG_STACK_VALIDATION
225 ifndef CONFIG_LTO_CLANG
227 __objtool_obj := $(objtree)/tools/objtool/objtool
229 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
230 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
231 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
232 cmd_objtool = $(if $(patsubst y%,, \
233 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
234 $(__objtool_obj) $(objtool_args) $@)
235 objtool_obj = $(if $(patsubst y%,, \
236 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
239 endif # CONFIG_LTO_CLANG
240 endif # CONFIG_STACK_VALIDATION
242 # Rebuild all objects when objtool changes, or is enabled/disabled.
243 objtool_dep = $(objtool_obj) \
244 $(wildcard include/config/ORC_UNWINDER \
245 include/config/STACK_VALIDATION)
247 ifdef CONFIG_TRIM_UNUSED_KSYMS
249 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
251 # List module undefined symbols
252 undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
256 $(call cmd_and_fixdep,cc_o_c)
257 $(call cmd,gen_ksymdeps)
261 $(call cmd,modversions_c)
262 $(call cmd,record_mcount)
266 $(call cmd_and_fixdep,as_o_S)
267 $(call cmd,gen_ksymdeps)
269 $(call cmd,modversions_S)
272 # Built-in and composite module parts
274 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
275 $(call if_changed_rule,cc_o_c)
276 $(call cmd,force_checksrc)
278 ifdef CONFIG_LTO_CLANG
279 # Module .o files may contain LLVM bitcode, compile them into native code
280 # before ELF processing
281 quiet_cmd_cc_lto_link_modules = LTO [M] $@
282 cmd_cc_lto_link_modules = \
283 $(LD) $(ld_flags) -r -o $@ \
284 $(shell [ -s $(@:.lto.o=.o.symversions) ] && \
285 echo -T $(@:.lto.o=.o.symversions)) \
286 --whole-archive $(filter-out FORCE,$^)
288 ifdef CONFIG_STACK_VALIDATION
289 # objtool was skipped for LLVM bitcode, run it now that we have compiled
290 # modules into native code
291 cmd_cc_lto_link_modules += ; \
292 $(objtree)/tools/objtool/objtool $(objtool_args) --module $@
295 $(obj)/%.lto.o: $(obj)/%.o FORCE
296 $(call if_changed,cc_lto_link_modules)
300 echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
301 $(undefined_syms) echo; \
304 $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE
305 $(call if_changed,mod)
307 quiet_cmd_cc_lst_c = MKLST $@
308 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
309 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
310 System.map $(OBJDUMP) > $@
312 $(obj)/%.lst: $(src)/%.c FORCE
313 $(call if_changed_dep,cc_lst_c)
315 # Compile assembler sources (.S)
316 # ---------------------------------------------------------------------------
318 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
319 # or a file that it includes, in order to get versioned symbols. We build a
320 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
321 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
323 # This is convoluted. The .S file must first be preprocessed to run guards and
324 # expand names, then the resulting exports must be constructed into plain
325 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
326 # to make the genksyms input.
328 # These mirror gensymtypes_c and co above, keep them in synch.
329 cmd_gensymtypes_S = \
330 { echo "\#include <linux/kernel.h>" ; \
331 echo "\#include <asm/asm-prototypes.h>" ; \
332 $(CPP) $(a_flags) $< | \
333 grep "\<___EXPORT_SYMBOL\>" | \
334 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
335 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
336 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
337 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
338 $(if $(KBUILD_PRESERVE),-p) \
339 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
341 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
342 cmd_cc_symtypes_S = \
343 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
344 test -s $@ || rm -f $@
346 $(obj)/%.symtypes : $(src)/%.S FORCE
347 $(call cmd,cc_symtypes_S)
350 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
351 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
353 $(obj)/%.s: $(src)/%.S FORCE
354 $(call if_changed_dep,cpp_s_S)
356 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
357 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
359 ifdef CONFIG_ASM_MODVERSIONS
361 # versioning matches the C process described above, with difference that
362 # we parse asm-prototypes.h C header to get function definitions.
364 cmd_modversions_S = \
365 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
366 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
367 > $(@D)/.tmp_$(@F:.o=.ver); \
369 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
370 -T $(@D)/.tmp_$(@F:.o=.ver); \
371 mv -f $(@D)/.tmp_$(@F) $@; \
372 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
376 $(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
377 $(call if_changed_rule,as_o_S)
379 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
380 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
381 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
383 # Linker scripts preprocessor (.lds.S -> .lds)
384 # ---------------------------------------------------------------------------
385 quiet_cmd_cpp_lds_S = LDS $@
386 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
387 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
389 $(obj)/%.lds: $(src)/%.lds.S FORCE
390 $(call if_changed_dep,cpp_lds_S)
393 # ---------------------------------------------------------------------------
394 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
395 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
396 $(basename $@).c $(basename $@).h
398 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
399 $(call cmd,asn1_compiler)
401 # Build the compiled-in targets
402 # ---------------------------------------------------------------------------
404 # To build objects in subdirs, we need to descend into the directories
405 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
406 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
408 # combine symversions for later processing
409 quiet_cmd_update_lto_symversions = SYMVER $@
410 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
411 cmd_update_lto_symversions = \
412 rm -f $@.symversions \
413 $(foreach n, $(filter-out FORCE,$^), \
414 $(if $(shell test -s $(n).symversions && echo y), \
415 ; cat $(n).symversions >> $@.symversions))
417 cmd_update_lto_symversions = echo >/dev/null
421 # Rule to compile a set of .o files into one .a file (without symbol table)
424 quiet_cmd_ar_builtin = AR $@
425 cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
427 quiet_cmd_ar_and_symver = AR $@
428 cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
430 $(obj)/built-in.a: $(real-obj-y) FORCE
431 $(call if_changed,ar_and_symver)
434 # Rule to create modules.order file
436 # Create commands to either record .ko file or cat modules.order from
438 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
439 # modules.order unless contained modules are updated.
441 cmd_modules_order = { $(foreach m, $(real-prereqs), \
442 $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
443 | $(AWK) '!x[$$0]++' - > $@
445 $(obj)/modules.order: $(obj-m) FORCE
446 $(call if_changed,modules_order)
449 # Rule to compile a set of .o files into one .a file (with symbol table)
451 quiet_cmd_ar_lib = AR $@
452 cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
454 $(obj)/lib.a: $(lib-y) FORCE
455 $(call if_changed,ar_lib)
458 # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
459 # module is turned into a multi object module, $^ will contain header file
460 # dependencies recorded in the .*.cmd file.
461 ifdef CONFIG_LTO_CLANG
462 quiet_cmd_link_multi-m = AR [M] $@
464 $(cmd_update_lto_symversions); \
466 $(AR) cDPrsT $@ $(filter %.o,$^)
468 quiet_cmd_link_multi-m = LD [M] $@
469 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
472 $(multi-obj-m): FORCE
473 $(call if_changed,link_multi-m)
474 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
476 targets += $(multi-obj-m)
477 targets := $(filter-out $(PHONY), $(targets))
479 # Add intermediate targets:
480 # When building objects with specific suffix patterns, add intermediate
481 # targets that the final targets are derived from.
482 intermediate_targets = $(foreach sfx, $(2), \
483 $(patsubst %$(strip $(1)),%$(sfx), \
484 $(filter %$(strip $(1)), $(targets))))
485 # %.asn1.o <- %.asn1.[ch] <- %.asn1
486 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
487 # %.lex.o <- %.lex.c <- %.l
488 # %.tab.o <- %.tab.[ch] <- %.y
489 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
490 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
491 $(call intermediate_targets, .lex.o, .lex.c) \
492 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
495 # ---------------------------------------------------------------------------
499 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
501 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
502 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
504 # Handle single targets without any rule: show "Nothing to be done for ..." or
505 # "No rule to make target ..." depending on whether the target exists.
506 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
507 $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
509 single-subdirs := $(foreach d, $(subdir-ym), \
510 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
512 __build: $(curdir-single) $(single-subdirs)
513 ifneq ($(unknown-single),)
514 $(Q)$(MAKE) -f /dev/null $(unknown-single)
518 ifeq ($(curdir-single),)
519 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
522 targets += $(curdir-single)
527 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
528 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
529 $(subdir-ym) $(always-y)
535 # ---------------------------------------------------------------------------
537 PHONY += $(subdir-ym)
539 $(Q)$(MAKE) $(build)=$@ \
540 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
541 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
542 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
544 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
545 # ---------------------------------------------------------------------------
551 # Read all saved command lines and dependencies for the $(targets) we
552 # may be building above, using $(if_changed{,_dep}). As an
553 # optimization, we don't need to read them if the target does not
554 # exist, we will rebuild anyway in that case.
556 existing-targets := $(wildcard $(sort $(targets)))
558 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
560 # Create directories for object files if they do not exist
561 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
562 # If targets exist, their directories apparently exist. Skip mkdir.
563 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
564 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
566 $(shell mkdir -p $(obj-dirs))