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, $(obj-m))))
91 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
92 targets-for-modules += $(patsubst %.o, %.prelink.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 genksyms = scripts/genksyms/genksyms \
130 $(if $(1), -T $(2)) \
131 $(if $(KBUILD_PRESERVE), -p) \
132 -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
134 # These mirror gensymtypes_S and co below, keep them in synch.
135 cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
137 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
138 cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
140 $(obj)/%.symtypes : $(src)/%.c FORCE
141 $(call cmd,cc_symtypes_c)
144 # Generate .ll files from .c
145 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
146 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
148 $(obj)/%.ll: $(src)/%.c FORCE
149 $(call if_changed_dep,cc_ll_c)
152 # The C file is compiled and updated dependency information is generated.
153 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
155 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
156 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< $(cmd_objtool)
158 ifdef CONFIG_MODVERSIONS
159 # When module versioning is enabled the following steps are executed:
160 # o compile a <file>.o from <file>.c
161 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
162 # not export symbols, it's done.
163 # o otherwise, we calculate symbol versions using the good old
164 # genksyms on the preprocessed source and dump them into the .cmd file.
165 # o modpost will extract versions from that file and create *.c files that will
166 # be compiled and linked to the kernel and/or modules.
169 if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
170 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
171 >> $(dot-target).cmd; \
174 cmd_gen_symversions_c = $(call gen_symversions,c)
178 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
179 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
180 ifdef BUILD_C_RECORDMCOUNT
181 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
182 RECORDMCOUNT_FLAGS = -w
184 # Due to recursion, we must skip empty.o.
185 # The empty.o file is created in the make process in order to determine
186 # the target endianness and word size. It is made before all other C
187 # files, including recordmcount.
188 sub_cmd_record_mcount = \
189 if [ $(@) != "scripts/mod/empty.o" ]; then \
190 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
192 recordmcount_source := $(srctree)/scripts/recordmcount.c \
193 $(srctree)/scripts/recordmcount.h
195 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
196 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
197 "$(if $(CONFIG_64BIT),64,32)" \
198 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
199 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
200 "$(if $(part-of-module),1,0)" "$(@)";
201 recordmcount_source := $(srctree)/scripts/recordmcount.pl
202 endif # BUILD_C_RECORDMCOUNT
203 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
204 $(sub_cmd_record_mcount))
205 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
209 objtool := $(objtree)/tools/objtool/objtool
212 $(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label) \
213 $(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr) \
214 $(if $(CONFIG_X86_KERNEL_IBT), --ibt) \
215 $(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount) \
216 $(if $(CONFIG_UNWINDER_ORC), --orc) \
217 $(if $(CONFIG_RETPOLINE), --retpoline) \
218 $(if $(CONFIG_SLS), --sls) \
219 $(if $(CONFIG_STACK_VALIDATION), --stackval) \
220 $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \
222 $(if $(linked-object), --link) \
223 $(if $(part-of-module), --module) \
224 $(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
226 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
227 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
229 endif # CONFIG_OBJTOOL
231 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
233 # Skip objtool for LLVM bitcode
234 $(obj)/%.o: objtool-enabled :=
238 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
239 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
240 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
242 $(obj)/%.o: objtool-enabled = $(if $(filter-out y%, \
243 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
247 ifdef CONFIG_TRIM_UNUSED_KSYMS
249 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
253 $(call cmd_and_fixdep,cc_o_c)
254 $(call cmd,gen_ksymdeps)
257 $(call cmd,gen_objtooldep)
258 $(call cmd,gen_symversions_c)
259 $(call cmd,record_mcount)
263 $(call cmd_and_fixdep,as_o_S)
264 $(call cmd,gen_ksymdeps)
265 $(call cmd,gen_objtooldep)
266 $(call cmd,gen_symversions_S)
269 # Built-in and composite module parts
270 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
271 $(call if_changed_rule,cc_o_c)
272 $(call cmd,force_checksrc)
274 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
275 # Module .o files may contain LLVM bitcode, compile them into native code
276 # before ELF processing
277 quiet_cmd_cc_prelink_modules = LD [M] $@
278 cmd_cc_prelink_modules = \
279 $(LD) $(ld_flags) -r -o $@ \
280 --whole-archive $(filter-out FORCE,$^) \
283 # objtool was skipped for LLVM bitcode, run it now that we have compiled
284 # modules into native code
285 $(obj)/%.prelink.o: objtool-enabled = y
286 $(obj)/%.prelink.o: part-of-module := y
287 $(obj)/%.prelink.o: linked-object := y
289 $(obj)/%.prelink.o: $(obj)/%.o FORCE
290 $(call if_changed,cc_prelink_modules)
293 cmd_mod = echo $(addprefix $(obj)/, $(call real-search, $*.o, .o, -objs -y -m)) | \
294 $(AWK) -v RS='( |\n)' '!x[$$0]++' > $@
297 $(call if_changed,mod)
299 # List module undefined symbols
300 cmd_undefined_syms = $(NM) $< | sed -n 's/^ *U //p' > $@
302 $(obj)/%.usyms: $(obj)/%$(mod-prelink-ext).o FORCE
303 $(call if_changed,undefined_syms)
305 quiet_cmd_cc_lst_c = MKLST $@
306 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
307 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
308 System.map $(OBJDUMP) > $@
310 $(obj)/%.lst: $(src)/%.c FORCE
311 $(call if_changed_dep,cc_lst_c)
313 # Compile assembler sources (.S)
314 # ---------------------------------------------------------------------------
316 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
317 # or a file that it includes, in order to get versioned symbols. We build a
318 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
319 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
321 # This is convoluted. The .S file must first be preprocessed to run guards and
322 # expand names, then the resulting exports must be constructed into plain
323 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
324 # to make the genksyms input.
326 # These mirror gensymtypes_c and co above, keep them in synch.
327 cmd_gensymtypes_S = \
328 { echo "\#include <linux/kernel.h>" ; \
329 echo "\#include <asm/asm-prototypes.h>" ; \
330 $(CPP) $(a_flags) $< | \
331 grep "\<___EXPORT_SYMBOL\>" | \
332 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
333 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
335 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
336 cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
338 $(obj)/%.symtypes : $(src)/%.S FORCE
339 $(call cmd,cc_symtypes_S)
342 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
343 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
345 $(obj)/%.s: $(src)/%.S FORCE
346 $(call if_changed_dep,cpp_s_S)
348 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
349 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
351 ifdef CONFIG_ASM_MODVERSIONS
353 # versioning matches the C process described above, with difference that
354 # we parse asm-prototypes.h C header to get function definitions.
356 cmd_gen_symversions_S = $(call gen_symversions,S)
360 $(obj)/%.o: $(src)/%.S FORCE
361 $(call if_changed_rule,as_o_S)
363 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
364 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
365 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
367 # Linker scripts preprocessor (.lds.S -> .lds)
368 # ---------------------------------------------------------------------------
369 quiet_cmd_cpp_lds_S = LDS $@
370 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
371 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
373 $(obj)/%.lds: $(src)/%.lds.S FORCE
374 $(call if_changed_dep,cpp_lds_S)
377 # ---------------------------------------------------------------------------
378 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
379 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
380 $(basename $@).c $(basename $@).h
382 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
383 $(call cmd,asn1_compiler)
385 # Build the compiled-in targets
386 # ---------------------------------------------------------------------------
388 # To build objects in subdirs, we need to descend into the directories
389 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
390 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
393 # Rule to compile a set of .o files into one .a file (without symbol table)
396 quiet_cmd_ar_builtin = AR $@
397 cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
399 $(obj)/built-in.a: $(real-obj-y) FORCE
400 $(call if_changed,ar_builtin)
403 # Rule to create modules.order file
405 # Create commands to either record .ko file or cat modules.order from
407 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
408 # modules.order unless contained modules are updated.
410 cmd_modules_order = { $(foreach m, $(real-prereqs), \
411 $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
412 | $(AWK) '!x[$$0]++' - > $@
414 $(obj)/modules.order: $(obj-m) FORCE
415 $(call if_changed,modules_order)
418 # Rule to compile a set of .o files into one .a file (with symbol table)
421 $(obj)/lib.a: $(lib-y) FORCE
422 $(call if_changed,ar)
424 ifneq ($(CONFIG_LTO_CLANG)$(CONFIG_X86_KERNEL_IBT),)
425 quiet_cmd_link_multi-m = AR [M] $@
428 $(AR) cDPrsT $@ @$(patsubst %.o,%.mod,$@)
430 quiet_cmd_link_multi-m = LD [M] $@
431 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@)
434 $(multi-obj-m): %.o: %.mod FORCE
435 $(call if_changed,link_multi-m)
436 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
438 targets := $(filter-out $(PHONY), $(targets))
440 # Add intermediate targets:
441 # When building objects with specific suffix patterns, add intermediate
442 # targets that the final targets are derived from.
443 intermediate_targets = $(foreach sfx, $(2), \
444 $(patsubst %$(strip $(1)),%$(sfx), \
445 $(filter %$(strip $(1)), $(targets))))
446 # %.asn1.o <- %.asn1.[ch] <- %.asn1
447 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
448 # %.lex.o <- %.lex.c <- %.l
449 # %.tab.o <- %.tab.[ch] <- %.y
450 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
451 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
452 $(call intermediate_targets, .lex.o, .lex.c) \
453 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
456 # ---------------------------------------------------------------------------
460 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
462 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
463 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
465 # Handle single targets without any rule: show "Nothing to be done for ..." or
466 # "No rule to make target ..." depending on whether the target exists.
467 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
468 $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
470 single-subdirs := $(foreach d, $(subdir-ym), \
471 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
473 __build: $(curdir-single) $(single-subdirs)
474 ifneq ($(unknown-single),)
475 $(Q)$(MAKE) -f /dev/null $(unknown-single)
479 ifeq ($(curdir-single),)
480 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
483 targets += $(curdir-single)
488 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
489 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
490 $(subdir-ym) $(always-y)
496 # ---------------------------------------------------------------------------
498 PHONY += $(subdir-ym)
500 $(Q)$(MAKE) $(build)=$@ \
501 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
502 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
503 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
505 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
506 # ---------------------------------------------------------------------------
512 # Read all saved command lines and dependencies for the $(targets) we
513 # may be building above, using $(if_changed{,_dep}). As an
514 # optimization, we don't need to read them if the target does not
515 # exist, we will rebuild anyway in that case.
517 existing-targets := $(wildcard $(sort $(targets)))
519 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
521 # Create directories for object files if they do not exist
522 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
523 # If targets exist, their directories apparently exist. Skip mkdir.
524 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
525 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
527 $(shell mkdir -p $(obj-dirs))