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 $(if $(CONFIG_TRIM_UNUSED_KSYMS), usyms), \
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 $<
107 # Compile C sources (.c)
108 # ---------------------------------------------------------------------------
110 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
111 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
113 $(obj)/%.s: $(src)/%.c FORCE
114 $(call if_changed_dep,cc_s_c)
116 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
117 cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
119 $(obj)/%.i: $(src)/%.c FORCE
120 $(call if_changed_dep,cpp_i_c)
122 genksyms = scripts/genksyms/genksyms \
123 $(if $(1), -T $(2)) \
124 $(if $(KBUILD_PRESERVE), -p) \
125 -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
127 # These mirror gensymtypes_S and co below, keep them in synch.
128 cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
130 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
131 cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
133 $(obj)/%.symtypes : $(src)/%.c FORCE
134 $(call cmd,cc_symtypes_c)
137 # Generate .ll files from .c
138 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
139 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
141 $(obj)/%.ll: $(src)/%.c FORCE
142 $(call if_changed_dep,cc_ll_c)
145 # The C file is compiled and updated dependency information is generated.
146 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
148 is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
150 # When a module consists of a single object, there is no reason to keep LLVM IR.
151 # Make $(LD) covert LLVM IR to ELF here.
152 ifdef CONFIG_LTO_CLANG
153 cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
156 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
157 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
161 ifdef CONFIG_MODVERSIONS
162 # When module versioning is enabled the following steps are executed:
163 # o compile a <file>.o from <file>.c
164 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
165 # not export symbols, it's done.
166 # o otherwise, we calculate symbol versions using the good old
167 # genksyms on the preprocessed source and dump them into the .cmd file.
168 # o modpost will extract versions from that file and create *.c files that will
169 # be compiled and linked to the kernel and/or modules.
172 if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
173 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
174 >> $(dot-target).cmd; \
177 cmd_gen_symversions_c = $(call gen_symversions,c)
181 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
182 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
183 ifdef BUILD_C_RECORDMCOUNT
184 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
185 RECORDMCOUNT_FLAGS = -w
187 # Due to recursion, we must skip empty.o.
188 # The empty.o file is created in the make process in order to determine
189 # the target endianness and word size. It is made before all other C
190 # files, including recordmcount.
191 sub_cmd_record_mcount = \
192 if [ $(@) != "scripts/mod/empty.o" ]; then \
193 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
195 recordmcount_source := $(srctree)/scripts/recordmcount.c \
196 $(srctree)/scripts/recordmcount.h
198 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
199 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
200 "$(if $(CONFIG_64BIT),64,32)" \
201 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
202 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
203 "$(if $(part-of-module),1,0)" "$(@)";
204 recordmcount_source := $(srctree)/scripts/recordmcount.pl
205 endif # BUILD_C_RECORDMCOUNT
206 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
207 $(sub_cmd_record_mcount))
208 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
210 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
211 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
212 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
214 is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
216 $(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
218 ifdef CONFIG_TRIM_UNUSED_KSYMS
220 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
223 cmd_check_local_export = $(srctree)/scripts/check-local-export $@
225 ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
226 cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
230 $(call cmd_and_fixdep,cc_o_c)
231 $(call cmd,gen_ksymdeps)
232 $(call cmd,check_local_export)
235 $(call cmd,gen_objtooldep)
236 $(call cmd,gen_symversions_c)
237 $(call cmd,record_mcount)
238 $(call cmd,warn_shared_object)
242 $(call cmd_and_fixdep,as_o_S)
243 $(call cmd,gen_ksymdeps)
244 $(call cmd,check_local_export)
245 $(call cmd,gen_objtooldep)
246 $(call cmd,gen_symversions_S)
247 $(call cmd,warn_shared_object)
250 # Built-in and composite module parts
251 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
252 $(call if_changed_rule,cc_o_c)
253 $(call cmd,force_checksrc)
255 # To make this rule robust against "Argument list too long" error,
256 # ensure to add $(obj)/ prefix by a shell command.
257 cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
258 $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
261 $(call if_changed,mod)
263 # List module undefined symbols
264 cmd_undefined_syms = $(NM) $< | sed -n 's/^ *U //p' > $@
266 $(obj)/%.usyms: $(obj)/%.o FORCE
267 $(call if_changed,undefined_syms)
269 quiet_cmd_cc_lst_c = MKLST $@
270 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
271 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
272 System.map $(OBJDUMP) > $@
274 $(obj)/%.lst: $(src)/%.c FORCE
275 $(call if_changed_dep,cc_lst_c)
277 # Compile Rust sources (.rs)
278 # ---------------------------------------------------------------------------
280 rust_allowed_features := core_ffi_c
283 RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
284 -Zallow-features=$(rust_allowed_features) \
285 -Zcrate-attr=no_std \
286 -Zcrate-attr='feature($(rust_allowed_features))' \
287 --extern alloc --extern kernel \
288 --crate-type rlib --out-dir $(obj) -L $(objtree)/rust/ \
289 --crate-name $(basename $(notdir $@))
291 rust_handle_depfile = \
292 mv $(obj)/$(basename $(notdir $@)).d $(depfile); \
293 sed -i '/^\#/d' $(depfile)
295 # `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
296 # will be used. We explicitly request `-Ccodegen-units=1` in any case, and
297 # the compiler shows a warning if it is not 1. However, if we ever stop
298 # requesting it explicitly and we start using some other `--emit` that does not
299 # imply it (and for which codegen is performed), then we would be out of sync,
300 # i.e. the outputs we would get for the different single targets (e.g. `.ll`)
301 # would not match each other.
303 quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
305 $(rust_common_cmd) --emit=dep-info,obj $<; \
306 $(rust_handle_depfile)
308 $(obj)/%.o: $(src)/%.rs FORCE
309 $(call if_changed_dep,rustc_o_rs)
311 quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
313 $(rust_common_cmd) --emit=dep-info -Zunpretty=expanded $< >$@; \
314 command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@; \
315 $(rust_handle_depfile)
317 $(obj)/%.rsi: $(src)/%.rs FORCE
318 $(call if_changed_dep,rustc_rsi_rs)
320 quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
322 $(rust_common_cmd) --emit=dep-info,asm $<; \
323 $(rust_handle_depfile)
325 $(obj)/%.s: $(src)/%.rs FORCE
326 $(call if_changed_dep,rustc_s_rs)
328 quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
330 $(rust_common_cmd) --emit=dep-info,llvm-ir $<; \
331 $(rust_handle_depfile)
333 $(obj)/%.ll: $(src)/%.rs FORCE
334 $(call if_changed_dep,rustc_ll_rs)
336 # Compile assembler sources (.S)
337 # ---------------------------------------------------------------------------
339 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
340 # or a file that it includes, in order to get versioned symbols. We build a
341 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
342 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
344 # This is convoluted. The .S file must first be preprocessed to run guards and
345 # expand names, then the resulting exports must be constructed into plain
346 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
347 # to make the genksyms input.
349 # These mirror gensymtypes_c and co above, keep them in synch.
350 cmd_gensymtypes_S = \
351 { echo "\#include <linux/kernel.h>" ; \
352 echo "\#include <asm/asm-prototypes.h>" ; \
353 $(CPP) $(a_flags) $< | \
354 grep "\<___EXPORT_SYMBOL\>" | \
355 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
356 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
358 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
359 cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
361 $(obj)/%.symtypes : $(src)/%.S FORCE
362 $(call cmd,cc_symtypes_S)
365 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
366 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
368 $(obj)/%.s: $(src)/%.S FORCE
369 $(call if_changed_dep,cpp_s_S)
371 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
372 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
374 ifdef CONFIG_ASM_MODVERSIONS
376 # versioning matches the C process described above, with difference that
377 # we parse asm-prototypes.h C header to get function definitions.
379 cmd_gen_symversions_S = $(call gen_symversions,S)
383 $(obj)/%.o: $(src)/%.S FORCE
384 $(call if_changed_rule,as_o_S)
386 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
387 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
388 targets += $(real-dtb-y) $(lib-y) $(always-y)
390 # Linker scripts preprocessor (.lds.S -> .lds)
391 # ---------------------------------------------------------------------------
392 quiet_cmd_cpp_lds_S = LDS $@
393 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
394 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
396 $(obj)/%.lds: $(src)/%.lds.S FORCE
397 $(call if_changed_dep,cpp_lds_S)
400 # ---------------------------------------------------------------------------
401 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
402 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
403 $(basename $@).c $(basename $@).h
405 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
406 $(call cmd,asn1_compiler)
408 # Build the compiled-in targets
409 # ---------------------------------------------------------------------------
411 # To build objects in subdirs, we need to descend into the directories
412 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
413 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
416 # Rule to compile a set of .o files into one .a file (without symbol table)
418 # To make this rule robust against "Argument list too long" error,
419 # remove $(obj)/ prefix, and restore it by a shell command.
421 quiet_cmd_ar_builtin = AR $@
422 cmd_ar_builtin = rm -f $@; \
423 $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
426 $(obj)/built-in.a: $(real-obj-y) FORCE
427 $(call if_changed,ar_builtin)
430 # Rule to create modules.order file
432 # Create commands to either record .ko file or cat modules.order from
434 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
435 # modules.order unless contained modules are updated.
437 cmd_modules_order = { $(foreach m, $(real-prereqs), \
438 $(if $(filter %/modules.order, $m), cat $m, echo $m);) :; } \
441 $(obj)/modules.order: $(obj-m) FORCE
442 $(call if_changed,modules_order)
445 # Rule to compile a set of .o files into one .a file (with symbol table)
448 $(obj)/lib.a: $(lib-y) FORCE
449 $(call if_changed,ar)
451 quiet_cmd_ld_multi_m = LD [M] $@
452 cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$(patsubst %.o,%.mod,$@) $(cmd_objtool)
454 define rule_ld_multi_m
455 $(call cmd_and_savecmd,ld_multi_m)
456 $(call cmd,gen_objtooldep)
459 $(multi-obj-m): objtool-enabled := $(delay-objtool)
460 $(multi-obj-m): part-of-module := y
461 $(multi-obj-m): %.o: %.mod FORCE
462 $(call if_changed_rule,ld_multi_m)
463 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
465 # Add intermediate targets:
466 # When building objects with specific suffix patterns, add intermediate
467 # targets that the final targets are derived from.
468 intermediate_targets = $(foreach sfx, $(2), \
469 $(patsubst %$(strip $(1)),%$(sfx), \
470 $(filter %$(strip $(1)), $(targets))))
471 # %.asn1.o <- %.asn1.[ch] <- %.asn1
472 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
473 # %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
474 # %.lex.o <- %.lex.c <- %.l
475 # %.tab.o <- %.tab.[ch] <- %.y
476 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
477 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
478 $(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo) \
479 $(call intermediate_targets, .lex.o, .lex.c) \
480 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
483 # ---------------------------------------------------------------------------
485 $(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
486 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
487 $(subdir-ym) $(always-y)
491 # ---------------------------------------------------------------------------
493 single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
494 single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
496 $(single-subdir-goals): $(single-subdirs)
500 # ---------------------------------------------------------------------------
502 PHONY += $(subdir-ym)
504 $(Q)$(MAKE) $(build)=$@ \
505 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
506 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
507 $(filter $@/%, $(single-subdir-goals))
509 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
510 # ---------------------------------------------------------------------------
516 targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
517 targets := $(filter-out $(PHONY), $(targets))
519 # Read all saved command lines and dependencies for the $(targets) we
520 # may be building above, using $(if_changed{,_dep}). As an
521 # optimization, we don't need to read them if the target does not
522 # exist, we will rebuild anyway in that case.
524 existing-targets := $(wildcard $(sort $(targets)))
526 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
528 # Create directories for object files if they do not exist
529 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
530 # If targets exist, their directories apparently exist. Skip mkdir.
531 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
532 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
534 $(shell mkdir -p $(obj-dirs))