1 # SPDX-License-Identifier: GPL-2.0
2 # ==========================================================================
4 # ==========================================================================
6 src := $(if $(VPATH),$(VPATH)/)$(obj)
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)))
74 subdir-dtbslist := $(sort $(filter %/dtbs-list, $(dtb-y)))
76 targets-for-builtin := $(extra-y)
78 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
79 targets-for-builtin += $(obj)/lib.a
83 targets-for-builtin += $(obj)/built-in.a
86 targets-for-modules := $(foreach x, o mod, \
87 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
90 targets-for-modules += $(obj)/modules.order
93 targets += $(targets-for-builtin) $(targets-for-modules)
95 # Linus' kernel sanity checking tool
96 ifeq ($(KBUILD_CHECKSRC),1)
97 quiet_cmd_checksrc = CHECK $<
98 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
99 else ifeq ($(KBUILD_CHECKSRC),2)
100 quiet_cmd_force_checksrc = CHECK $<
101 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
104 ifneq ($(KBUILD_EXTRA_WARN),)
105 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $(KDOCFLAGS) \
106 $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \
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: $(obj)/%.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: $(obj)/%.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 : $(obj)/%.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 -fno-discard-value-names -o $@ $<
144 $(obj)/%.ll: $(obj)/%.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 __export_symbol_*, 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 ' __export_symbol_'; 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
213 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
214 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
215 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
217 is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),$(is-kernel-object))
219 $(obj)/%.o: private objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
221 ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
222 cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
226 $(call cmd_and_fixdep,cc_o_c)
229 $(call cmd,gen_objtooldep)
230 $(call cmd,gen_symversions_c)
231 $(call cmd,record_mcount)
232 $(call cmd,warn_shared_object)
236 $(call cmd_and_fixdep,as_o_S)
237 $(call cmd,gen_objtooldep)
238 $(call cmd,gen_symversions_S)
239 $(call cmd,warn_shared_object)
242 # Built-in and composite module parts
243 $(obj)/%.o: $(obj)/%.c $(recordmcount_source) FORCE
244 $(call if_changed_rule,cc_o_c)
245 $(call cmd,force_checksrc)
247 # To make this rule robust against "Argument list too long" error,
248 # ensure to add $(obj)/ prefix by a shell command.
249 cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
250 $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
253 $(call if_changed,mod)
255 quiet_cmd_cc_lst_c = MKLST $@
256 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
257 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
258 System.map $(OBJDUMP) > $@
260 $(obj)/%.lst: $(obj)/%.c FORCE
261 $(call if_changed_dep,cc_lst_c)
263 # Compile Rust sources (.rs)
264 # ---------------------------------------------------------------------------
266 rust_allowed_features := new_uninit
268 # `--out-dir` is required to avoid temporaries being created by `rustc` in the
269 # current working directory, which may be not accessible in the out-of-tree
272 RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
273 -Zallow-features=$(rust_allowed_features) \
274 -Zcrate-attr=no_std \
275 -Zcrate-attr='feature($(rust_allowed_features))' \
276 -Zunstable-options --extern force:alloc --extern kernel \
277 --crate-type rlib -L $(objtree)/rust/ \
278 --crate-name $(basename $(notdir $@)) \
279 --sysroot=/dev/null \
280 --out-dir $(dir $@) --emit=dep-info=$(depfile)
282 # `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
283 # will be used. We explicitly request `-Ccodegen-units=1` in any case, and
284 # the compiler shows a warning if it is not 1. However, if we ever stop
285 # requesting it explicitly and we start using some other `--emit` that does not
286 # imply it (and for which codegen is performed), then we would be out of sync,
287 # i.e. the outputs we would get for the different single targets (e.g. `.ll`)
288 # would not match each other.
290 quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
291 cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $<
293 $(obj)/%.o: $(obj)/%.rs FORCE
294 +$(call if_changed_dep,rustc_o_rs)
296 quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
298 $(rust_common_cmd) -Zunpretty=expanded $< >$@; \
299 command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@
301 $(obj)/%.rsi: $(obj)/%.rs FORCE
302 +$(call if_changed_dep,rustc_rsi_rs)
304 quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
305 cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
307 $(obj)/%.s: $(obj)/%.rs FORCE
308 +$(call if_changed_dep,rustc_s_rs)
310 quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
311 cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
313 $(obj)/%.ll: $(obj)/%.rs FORCE
314 +$(call if_changed_dep,rustc_ll_rs)
316 # Compile assembler sources (.S)
317 # ---------------------------------------------------------------------------
319 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
320 # or a file that it includes, in order to get versioned symbols. We build a
321 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
322 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
324 # This is convoluted. The .S file must first be preprocessed to run guards and
325 # expand names, then the resulting exports must be constructed into plain
326 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
327 # to make the genksyms input.
329 # These mirror gensymtypes_c and co above, keep them in synch.
330 cmd_gensymtypes_S = \
331 { echo "\#include <linux/kernel.h>" ; \
332 echo "\#include <asm/asm-prototypes.h>" ; \
333 $(NM) $@ | sed -n 's/.* __export_symbol_\(.*\)/EXPORT_SYMBOL(\1);/p' ; } | \
334 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
336 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
337 cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
339 $(obj)/%.symtypes : $(obj)/%.S FORCE
340 $(call cmd,cc_symtypes_S)
343 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
344 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
346 $(obj)/%.s: $(obj)/%.S FORCE
347 $(call if_changed_dep,cpp_s_S)
349 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
350 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
352 ifdef CONFIG_ASM_MODVERSIONS
354 # versioning matches the C process described above, with difference that
355 # we parse asm-prototypes.h C header to get function definitions.
357 cmd_gen_symversions_S = $(call gen_symversions,S)
361 $(obj)/%.o: $(obj)/%.S FORCE
362 $(call if_changed_rule,as_o_S)
364 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
365 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
366 targets += $(real-dtb-y) $(lib-y) $(always-y)
368 # Linker scripts preprocessor (.lds.S -> .lds)
369 # ---------------------------------------------------------------------------
370 quiet_cmd_cpp_lds_S = LDS $@
371 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
372 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
374 $(obj)/%.lds: $(src)/%.lds.S FORCE
375 $(call if_changed_dep,cpp_lds_S)
378 # ---------------------------------------------------------------------------
379 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
380 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
381 $(basename $@).c $(basename $@).h
383 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
384 $(call cmd,asn1_compiler)
386 # Build the compiled-in targets
387 # ---------------------------------------------------------------------------
389 # To build objects in subdirs, we need to descend into the directories
390 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
391 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
392 $(subdir-dtbslist): $(obj)/%/dtbs-list: $(obj)/% ;
395 # Rule to compile a set of .o files into one .a file (without symbol table)
397 # To make this rule robust against "Argument list too long" error,
398 # remove $(obj)/ prefix, and restore it by a shell command.
400 quiet_cmd_ar_builtin = AR $@
401 cmd_ar_builtin = rm -f $@; \
402 $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
405 $(obj)/built-in.a: $(real-obj-y) FORCE
406 $(call if_changed,ar_builtin)
409 # Rule to create modules.order and dtbs-list
411 # This is a list of build artifacts (module or dtb) from the current Makefile
412 # and its sub-directories. The timestamp should be updated when any of the
415 cmd_gen_order = { $(foreach m, $(real-prereqs), \
416 $(if $(filter %/$(notdir $@), $m), cat $m, echo $m);) :; } \
419 $(obj)/modules.order: $(obj-m) FORCE
420 $(call if_changed,gen_order)
422 $(obj)/dtbs-list: $(dtb-y) FORCE
423 $(call if_changed,gen_order)
426 # Rule to compile a set of .o files into one .a file (with symbol table)
429 $(obj)/lib.a: $(lib-y) FORCE
430 $(call if_changed,ar)
432 quiet_cmd_ld_multi_m = LD [M] $@
433 cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
435 define rule_ld_multi_m
436 $(call cmd_and_savecmd,ld_multi_m)
437 $(call cmd,gen_objtooldep)
440 $(multi-obj-m): private objtool-enabled := $(delay-objtool)
441 $(multi-obj-m): private part-of-module := y
442 $(multi-obj-m): %.o: %.mod FORCE
443 $(call if_changed_rule,ld_multi_m)
444 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
446 # Add intermediate targets:
447 # When building objects with specific suffix patterns, add intermediate
448 # targets that the final targets are derived from.
449 intermediate_targets = $(foreach sfx, $(2), \
450 $(patsubst %$(strip $(1)),%$(sfx), \
451 $(filter %$(strip $(1)), $(targets))))
452 # %.asn1.o <- %.asn1.[ch] <- %.asn1
453 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
454 # %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
455 # %.lex.o <- %.lex.c <- %.l
456 # %.tab.o <- %.tab.[ch] <- %.y
457 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
458 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
459 $(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo) \
460 $(call intermediate_targets, .lex.o, .lex.c) \
461 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
464 # ---------------------------------------------------------------------------
466 $(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
467 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
468 $(subdir-ym) $(always-y)
472 # ---------------------------------------------------------------------------
474 single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
475 single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
477 $(single-subdir-goals): $(single-subdirs)
481 # ---------------------------------------------------------------------------
483 PHONY += $(subdir-ym)
485 $(Q)$(MAKE) $(build)=$@ \
486 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
487 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
488 $(filter $@/%, $(single-subdir-goals))
490 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
491 # ---------------------------------------------------------------------------
497 targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
498 targets := $(filter-out $(PHONY), $(targets))
500 # Read all saved command lines and dependencies for the $(targets) we
501 # may be building above, using $(if_changed{,_dep}). As an
502 # optimization, we don't need to read them if the target does not
503 # exist, we will rebuild anyway in that case.
505 existing-targets := $(wildcard $(sort $(targets)))
507 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
509 # Create directories for object files if they do not exist
510 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
511 # If targets exist, their directories apparently exist. Skip mkdir.
512 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
513 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
515 $(shell mkdir -p $(obj-dirs))