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 include $(or $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Makefile)
45 include $(srctree)/scripts/Makefile.lib
47 # Do not include hostprogs rules unless needed.
48 # $(sort ...) is used here to remove duplicated words and excessive spaces.
49 hostprogs := $(sort $(hostprogs))
51 include $(srctree)/scripts/Makefile.host
54 # Do not include userprogs rules unless needed.
55 # $(sort ...) is used here to remove duplicated words and excessive spaces.
56 userprogs := $(sort $(userprogs))
58 include $(srctree)/scripts/Makefile.userprogs
62 $(warning kbuild: Makefile.build is included improperly)
65 ifeq ($(need-modorder),)
67 $(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
68 $(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
72 # ===========================================================================
74 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
75 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
76 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
78 targets-for-builtin := $(extra-y)
80 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
81 targets-for-builtin += $(obj)/lib.a
85 targets-for-builtin += $(obj)/built-in.a
88 targets-for-modules := $(foreach x, o mod $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
89 $(patsubst %.o, %.$x, $(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 genksyms = scripts/genksyms/genksyms \
126 $(if $(1), -T $(2)) \
127 $(if $(KBUILD_PRESERVE), -p) \
128 -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
130 # These mirror gensymtypes_S and co below, keep them in synch.
131 cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
133 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
134 cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
136 $(obj)/%.symtypes : $(src)/%.c FORCE
137 $(call cmd,cc_symtypes_c)
140 # Generate .ll files from .c
141 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
142 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
144 $(obj)/%.ll: $(src)/%.c FORCE
145 $(call if_changed_dep,cc_ll_c)
148 # The C file is compiled and updated dependency information is generated.
149 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
151 is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
153 # When a module consists of a single object, there is no reason to keep LLVM IR.
154 # Make $(LD) covert LLVM IR to ELF here.
155 ifdef CONFIG_LTO_CLANG
156 cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
159 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
160 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
164 ifdef CONFIG_MODVERSIONS
165 # When module versioning is enabled the following steps are executed:
166 # o compile a <file>.o from <file>.c
167 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
168 # not export symbols, it's done.
169 # o otherwise, we calculate symbol versions using the good old
170 # genksyms on the preprocessed source and dump them into the .cmd file.
171 # o modpost will extract versions from that file and create *.c files that will
172 # be compiled and linked to the kernel and/or modules.
175 if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
176 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
177 >> $(dot-target).cmd; \
180 cmd_gen_symversions_c = $(call gen_symversions,c)
184 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
185 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
186 ifdef BUILD_C_RECORDMCOUNT
187 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
188 RECORDMCOUNT_FLAGS = -w
190 # Due to recursion, we must skip empty.o.
191 # The empty.o file is created in the make process in order to determine
192 # the target endianness and word size. It is made before all other C
193 # files, including recordmcount.
194 sub_cmd_record_mcount = \
195 if [ $(@) != "scripts/mod/empty.o" ]; then \
196 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
198 recordmcount_source := $(srctree)/scripts/recordmcount.c \
199 $(srctree)/scripts/recordmcount.h
201 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
202 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
203 "$(if $(CONFIG_64BIT),64,32)" \
204 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
205 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
206 "$(if $(part-of-module),1,0)" "$(@)";
207 recordmcount_source := $(srctree)/scripts/recordmcount.pl
208 endif # BUILD_C_RECORDMCOUNT
209 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
210 $(sub_cmd_record_mcount))
211 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
215 objtool := $(objtree)/tools/objtool/objtool
218 $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
219 $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
220 $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
221 $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
222 $(if $(CONFIG_UNWINDER_ORC), --orc) \
223 $(if $(CONFIG_RETPOLINE), --retpoline) \
224 $(if $(CONFIG_SLS), --sls) \
225 $(if $(CONFIG_STACK_VALIDATION), --stackval) \
226 $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \
228 $(if $(delay-objtool), --link) \
229 $(if $(part-of-module), --module) \
230 $(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
232 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
233 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
235 endif # CONFIG_OBJTOOL
237 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
238 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
239 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
241 is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
243 delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
245 $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
247 ifdef CONFIG_TRIM_UNUSED_KSYMS
249 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
252 cmd_check_local_export = $(srctree)/scripts/check-local-export $@
255 $(call cmd_and_fixdep,cc_o_c)
256 $(call cmd,gen_ksymdeps)
257 $(call cmd,check_local_export)
260 $(call cmd,gen_objtooldep)
261 $(call cmd,gen_symversions_c)
262 $(call cmd,record_mcount)
266 $(call cmd_and_fixdep,as_o_S)
267 $(call cmd,gen_ksymdeps)
268 $(call cmd,check_local_export)
269 $(call cmd,gen_objtooldep)
270 $(call cmd,gen_symversions_S)
273 # Built-in and composite module parts
274 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
275 $(call if_changed_rule,cc_o_c)
276 $(call cmd,force_checksrc)
278 cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \
279 $(AWK) -v RS='( |\n)' '!x[$$0]++' > $@
282 $(call if_changed,mod)
284 # List module undefined symbols
285 cmd_undefined_syms = $(NM) $< | sed -n 's/^ *U //p' > $@
287 $(obj)/%.usyms: $(obj)/%.o FORCE
288 $(call if_changed,undefined_syms)
290 quiet_cmd_cc_lst_c = MKLST $@
291 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
292 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
293 System.map $(OBJDUMP) > $@
295 $(obj)/%.lst: $(src)/%.c FORCE
296 $(call if_changed_dep,cc_lst_c)
298 # Compile assembler sources (.S)
299 # ---------------------------------------------------------------------------
301 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
302 # or a file that it includes, in order to get versioned symbols. We build a
303 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
304 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
306 # This is convoluted. The .S file must first be preprocessed to run guards and
307 # expand names, then the resulting exports must be constructed into plain
308 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
309 # to make the genksyms input.
311 # These mirror gensymtypes_c and co above, keep them in synch.
312 cmd_gensymtypes_S = \
313 { echo "\#include <linux/kernel.h>" ; \
314 echo "\#include <asm/asm-prototypes.h>" ; \
315 $(CPP) $(a_flags) $< | \
316 grep "\<___EXPORT_SYMBOL\>" | \
317 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
318 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
320 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
321 cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
323 $(obj)/%.symtypes : $(src)/%.S FORCE
324 $(call cmd,cc_symtypes_S)
327 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
328 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
330 $(obj)/%.s: $(src)/%.S FORCE
331 $(call if_changed_dep,cpp_s_S)
333 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
334 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
336 ifdef CONFIG_ASM_MODVERSIONS
338 # versioning matches the C process described above, with difference that
339 # we parse asm-prototypes.h C header to get function definitions.
341 cmd_gen_symversions_S = $(call gen_symversions,S)
345 $(obj)/%.o: $(src)/%.S FORCE
346 $(call if_changed_rule,as_o_S)
348 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
349 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
350 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
352 # Linker scripts preprocessor (.lds.S -> .lds)
353 # ---------------------------------------------------------------------------
354 quiet_cmd_cpp_lds_S = LDS $@
355 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
356 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
358 $(obj)/%.lds: $(src)/%.lds.S FORCE
359 $(call if_changed_dep,cpp_lds_S)
362 # ---------------------------------------------------------------------------
363 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
364 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
365 $(basename $@).c $(basename $@).h
367 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
368 $(call cmd,asn1_compiler)
370 # Build the compiled-in targets
371 # ---------------------------------------------------------------------------
373 # To build objects in subdirs, we need to descend into the directories
374 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
375 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
378 # Rule to compile a set of .o files into one .a file (without symbol table)
381 quiet_cmd_ar_builtin = AR $@
382 cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
384 $(obj)/built-in.a: $(real-obj-y) FORCE
385 $(call if_changed,ar_builtin)
388 # Rule to create modules.order file
390 # Create commands to either record .ko file or cat modules.order from
392 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
393 # modules.order unless contained modules are updated.
395 cmd_modules_order = { $(foreach m, $(real-prereqs), \
396 $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
397 | $(AWK) '!x[$$0]++' - > $@
399 $(obj)/modules.order: $(obj-m) FORCE
400 $(call if_changed,modules_order)
403 # Rule to compile a set of .o files into one .a file (with symbol table)
406 $(obj)/lib.a: $(lib-y) FORCE
407 $(call if_changed,ar)
409 quiet_cmd_link_multi-m = LD [M] $@
410 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool)
412 $(multi-obj-m): objtool-enabled := $(delay-objtool)
413 $(multi-obj-m): part-of-module := y
414 $(multi-obj-m): %.o: %.mod FORCE
415 $(call if_changed,link_multi-m)
416 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
418 targets := $(filter-out $(PHONY), $(targets))
420 # Add intermediate targets:
421 # When building objects with specific suffix patterns, add intermediate
422 # targets that the final targets are derived from.
423 intermediate_targets = $(foreach sfx, $(2), \
424 $(patsubst %$(strip $(1)),%$(sfx), \
425 $(filter %$(strip $(1)), $(targets))))
426 # %.asn1.o <- %.asn1.[ch] <- %.asn1
427 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
428 # %.lex.o <- %.lex.c <- %.l
429 # %.tab.o <- %.tab.[ch] <- %.y
430 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
431 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
432 $(call intermediate_targets, .lex.o, .lex.c) \
433 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
436 # ---------------------------------------------------------------------------
440 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
442 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
443 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
445 # Handle single targets without any rule: show "Nothing to be done for ..." or
446 # "No rule to make target ..." depending on whether the target exists.
447 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
448 $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
450 single-subdirs := $(foreach d, $(subdir-ym), \
451 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
453 __build: $(curdir-single) $(single-subdirs)
454 ifneq ($(unknown-single),)
455 $(Q)$(MAKE) -f /dev/null $(unknown-single)
459 ifeq ($(curdir-single),)
460 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
463 targets += $(curdir-single)
468 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
469 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
470 $(subdir-ym) $(always-y)
476 # ---------------------------------------------------------------------------
478 PHONY += $(subdir-ym)
480 $(Q)$(MAKE) $(build)=$@ \
481 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
482 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
483 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
485 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
486 # ---------------------------------------------------------------------------
492 # Read all saved command lines and dependencies for the $(targets) we
493 # may be building above, using $(if_changed{,_dep}). As an
494 # optimization, we don't need to read them if the target does not
495 # exist, we will rebuild anyway in that case.
497 existing-targets := $(wildcard $(sort $(targets)))
499 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
501 # Create directories for object files if they do not exist
502 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
503 # If targets exist, their directories apparently exist. Skip mkdir.
504 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
505 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
507 $(shell mkdir -p $(obj-dirs))