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 $(srctree)/scripts/Kbuild.include
40 include $(srctree)/scripts/Makefile.compiler
41 include $(kbuild-file)
42 include $(srctree)/scripts/Makefile.lib
44 # Do not include hostprogs rules unless needed.
45 # $(sort ...) is used here to remove duplicated words and excessive spaces.
46 hostprogs := $(sort $(hostprogs))
48 include $(srctree)/scripts/Makefile.host
51 # Do not include userprogs rules unless needed.
52 # $(sort ...) is used here to remove duplicated words and excessive spaces.
53 userprogs := $(sort $(userprogs))
55 include $(srctree)/scripts/Makefile.userprogs
59 $(warning kbuild: Makefile.build is included improperly)
62 ifeq ($(need-modorder),)
64 $(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
65 $(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
69 # ===========================================================================
71 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
72 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
73 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
75 targets-for-builtin := $(extra-y)
77 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
78 targets-for-builtin += $(obj)/lib.a
82 targets-for-builtin += $(obj)/built-in.a
85 targets-for-modules := $(foreach x, o mod, \
86 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
89 targets-for-modules += $(obj)/modules.order
92 targets += $(targets-for-builtin) $(targets-for-modules)
94 # Linus' kernel sanity checking tool
95 ifeq ($(KBUILD_CHECKSRC),1)
96 quiet_cmd_checksrc = CHECK $<
97 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
98 else ifeq ($(KBUILD_CHECKSRC),2)
99 quiet_cmd_force_checksrc = CHECK $<
100 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
103 ifneq ($(KBUILD_EXTRA_WARN),)
104 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $(KDOCFLAGS) \
105 $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \
109 # Compile C sources (.c)
110 # ---------------------------------------------------------------------------
112 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
113 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
115 $(obj)/%.s: $(src)/%.c FORCE
116 $(call if_changed_dep,cc_s_c)
118 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
119 cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
121 $(obj)/%.i: $(src)/%.c FORCE
122 $(call if_changed_dep,cpp_i_c)
124 genksyms = scripts/genksyms/genksyms \
125 $(if $(1), -T $(2)) \
126 $(if $(KBUILD_PRESERVE), -p) \
127 -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
129 # These mirror gensymtypes_S and co below, keep them in synch.
130 cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
132 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
133 cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
135 $(obj)/%.symtypes : $(src)/%.c FORCE
136 $(call cmd,cc_symtypes_c)
139 # Generate .ll files from .c
140 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
141 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
143 $(obj)/%.ll: $(src)/%.c FORCE
144 $(call if_changed_dep,cc_ll_c)
147 # The C file is compiled and updated dependency information is generated.
148 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
150 is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
152 # When a module consists of a single object, there is no reason to keep LLVM IR.
153 # Make $(LD) covert LLVM IR to ELF here.
154 ifdef CONFIG_LTO_CLANG
155 cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
158 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
159 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
163 ifdef CONFIG_MODVERSIONS
164 # When module versioning is enabled the following steps are executed:
165 # o compile a <file>.o from <file>.c
166 # o if <file>.o doesn't contain a __export_symbol_*, i.e. does
167 # not export symbols, it's done.
168 # o otherwise, we calculate symbol versions using the good old
169 # genksyms on the preprocessed source and dump them into the .cmd file.
170 # o modpost will extract versions from that file and create *.c files that will
171 # be compiled and linked to the kernel and/or modules.
174 if $(NM) $@ 2>/dev/null | grep -q ' __export_symbol_'; then \
175 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
176 >> $(dot-target).cmd; \
179 cmd_gen_symversions_c = $(call gen_symversions,c)
183 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
184 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
185 ifdef BUILD_C_RECORDMCOUNT
186 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
187 RECORDMCOUNT_FLAGS = -w
189 # Due to recursion, we must skip empty.o.
190 # The empty.o file is created in the make process in order to determine
191 # the target endianness and word size. It is made before all other C
192 # files, including recordmcount.
193 sub_cmd_record_mcount = \
194 if [ $(@) != "scripts/mod/empty.o" ]; then \
195 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
197 recordmcount_source := $(srctree)/scripts/recordmcount.c \
198 $(srctree)/scripts/recordmcount.h
200 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
201 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
202 "$(if $(CONFIG_64BIT),64,32)" \
203 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
204 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
205 "$(if $(part-of-module),1,0)" "$(@)";
206 recordmcount_source := $(srctree)/scripts/recordmcount.pl
207 endif # BUILD_C_RECORDMCOUNT
208 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
209 $(sub_cmd_record_mcount))
210 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
212 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
213 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
214 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
216 is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
218 $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
220 ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
221 cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
225 $(call cmd_and_fixdep,cc_o_c)
228 $(call cmd,gen_objtooldep)
229 $(call cmd,gen_symversions_c)
230 $(call cmd,record_mcount)
231 $(call cmd,warn_shared_object)
235 $(call cmd_and_fixdep,as_o_S)
236 $(call cmd,gen_objtooldep)
237 $(call cmd,gen_symversions_S)
238 $(call cmd,warn_shared_object)
241 # Built-in and composite module parts
242 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
243 $(call if_changed_rule,cc_o_c)
244 $(call cmd,force_checksrc)
246 # To make this rule robust against "Argument list too long" error,
247 # ensure to add $(obj)/ prefix by a shell command.
248 cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
249 $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
252 $(call if_changed,mod)
254 quiet_cmd_cc_lst_c = MKLST $@
255 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
256 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
257 System.map $(OBJDUMP) > $@
259 $(obj)/%.lst: $(src)/%.c FORCE
260 $(call if_changed_dep,cc_lst_c)
262 # Compile Rust sources (.rs)
263 # ---------------------------------------------------------------------------
265 rust_allowed_features := core_ffi_c,explicit_generic_args_with_impl_trait,new_uninit,pin_macro
268 RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
269 -Zallow-features=$(rust_allowed_features) \
270 -Zcrate-attr=no_std \
271 -Zcrate-attr='feature($(rust_allowed_features))' \
272 --extern alloc --extern kernel \
273 --crate-type rlib -L $(objtree)/rust/ \
274 --crate-name $(basename $(notdir $@)) \
275 --emit=dep-info=$(depfile)
277 # `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
278 # will be used. We explicitly request `-Ccodegen-units=1` in any case, and
279 # the compiler shows a warning if it is not 1. However, if we ever stop
280 # requesting it explicitly and we start using some other `--emit` that does not
281 # imply it (and for which codegen is performed), then we would be out of sync,
282 # i.e. the outputs we would get for the different single targets (e.g. `.ll`)
283 # would not match each other.
285 quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
286 cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $<
288 $(obj)/%.o: $(src)/%.rs FORCE
289 $(call if_changed_dep,rustc_o_rs)
291 quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
293 $(rust_common_cmd) -Zunpretty=expanded $< >$@; \
294 command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@
296 $(obj)/%.rsi: $(src)/%.rs FORCE
297 $(call if_changed_dep,rustc_rsi_rs)
299 quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
300 cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
302 $(obj)/%.s: $(src)/%.rs FORCE
303 $(call if_changed_dep,rustc_s_rs)
305 quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
306 cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
308 $(obj)/%.ll: $(src)/%.rs FORCE
309 $(call if_changed_dep,rustc_ll_rs)
311 # Compile assembler sources (.S)
312 # ---------------------------------------------------------------------------
314 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
315 # or a file that it includes, in order to get versioned symbols. We build a
316 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
317 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
319 # This is convoluted. The .S file must first be preprocessed to run guards and
320 # expand names, then the resulting exports must be constructed into plain
321 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
322 # to make the genksyms input.
324 # These mirror gensymtypes_c and co above, keep them in synch.
325 cmd_gensymtypes_S = \
326 { echo "\#include <linux/kernel.h>" ; \
327 echo "\#include <asm/asm-prototypes.h>" ; \
328 $(NM) $@ | sed -n 's/.* __export_symbol_\(.*\)/EXPORT_SYMBOL(\1);/p' ; } | \
329 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
331 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
332 cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
334 $(obj)/%.symtypes : $(src)/%.S FORCE
335 $(call cmd,cc_symtypes_S)
338 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
339 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
341 $(obj)/%.s: $(src)/%.S FORCE
342 $(call if_changed_dep,cpp_s_S)
344 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
345 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
347 ifdef CONFIG_ASM_MODVERSIONS
349 # versioning matches the C process described above, with difference that
350 # we parse asm-prototypes.h C header to get function definitions.
352 cmd_gen_symversions_S = $(call gen_symversions,S)
356 $(obj)/%.o: $(src)/%.S FORCE
357 $(call if_changed_rule,as_o_S)
359 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
360 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
361 targets += $(real-dtb-y) $(lib-y) $(always-y)
363 # Linker scripts preprocessor (.lds.S -> .lds)
364 # ---------------------------------------------------------------------------
365 quiet_cmd_cpp_lds_S = LDS $@
366 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
367 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
369 $(obj)/%.lds: $(src)/%.lds.S FORCE
370 $(call if_changed_dep,cpp_lds_S)
373 # ---------------------------------------------------------------------------
374 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
375 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
376 $(basename $@).c $(basename $@).h
378 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
379 $(call cmd,asn1_compiler)
381 # Build the compiled-in targets
382 # ---------------------------------------------------------------------------
384 # To build objects in subdirs, we need to descend into the directories
385 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
386 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
389 # Rule to compile a set of .o files into one .a file (without symbol table)
391 # To make this rule robust against "Argument list too long" error,
392 # remove $(obj)/ prefix, and restore it by a shell command.
394 quiet_cmd_ar_builtin = AR $@
395 cmd_ar_builtin = rm -f $@; \
396 $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
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 $m);) :; } \
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 quiet_cmd_ld_multi_m = LD [M] $@
425 cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool)
427 define rule_ld_multi_m
428 $(call cmd_and_savecmd,ld_multi_m)
429 $(call cmd,gen_objtooldep)
432 $(multi-obj-m): objtool-enabled := $(delay-objtool)
433 $(multi-obj-m): part-of-module := y
434 $(multi-obj-m): %.o: %.mod FORCE
435 $(call if_changed_rule,ld_multi_m)
436 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
438 # Add intermediate targets:
439 # When building objects with specific suffix patterns, add intermediate
440 # targets that the final targets are derived from.
441 intermediate_targets = $(foreach sfx, $(2), \
442 $(patsubst %$(strip $(1)),%$(sfx), \
443 $(filter %$(strip $(1)), $(targets))))
444 # %.asn1.o <- %.asn1.[ch] <- %.asn1
445 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
446 # %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
447 # %.lex.o <- %.lex.c <- %.l
448 # %.tab.o <- %.tab.[ch] <- %.y
449 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
450 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
451 $(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo) \
452 $(call intermediate_targets, .lex.o, .lex.c) \
453 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
456 # ---------------------------------------------------------------------------
458 $(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
459 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
460 $(subdir-ym) $(always-y)
464 # ---------------------------------------------------------------------------
466 single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
467 single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
469 $(single-subdir-goals): $(single-subdirs)
473 # ---------------------------------------------------------------------------
475 PHONY += $(subdir-ym)
477 $(Q)$(MAKE) $(build)=$@ \
478 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
479 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
480 $(filter $@/%, $(single-subdir-goals))
482 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
483 # ---------------------------------------------------------------------------
489 targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
490 targets := $(filter-out $(PHONY), $(targets))
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))