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 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44 include $(kbuild-file)
46 include $(srctree)/scripts/Makefile.lib
48 # Do not include hostprogs rules unless needed.
49 # $(sort ...) is used here to remove duplicated words and excessive spaces.
50 hostprogs := $(sort $(hostprogs))
52 include $(srctree)/scripts/Makefile.host
55 # Do not include userprogs rules unless needed.
56 # $(sort ...) is used here to remove duplicated words and excessive spaces.
57 userprogs := $(sort $(userprogs))
59 include $(srctree)/scripts/Makefile.userprogs
63 $(warning kbuild: Makefile.build is included improperly)
66 ifeq ($(need-modorder),)
68 $(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
69 $(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
73 # ===========================================================================
75 # subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
76 subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
77 subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
79 targets-for-builtin := $(extra-y)
81 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
82 targets-for-builtin += $(obj)/lib.a
86 targets-for-builtin += $(obj)/built-in.a
89 targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
91 ifdef CONFIG_LTO_CLANG
92 targets-for-modules += $(patsubst %.o, %.lto.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 # These mirror gensymtypes_S and co below, keep them in synch.
130 cmd_gensymtypes_c = \
131 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
132 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
133 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
134 $(if $(KBUILD_PRESERVE),-p) \
135 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
137 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
138 cmd_cc_symtypes_c = \
139 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
140 test -s $@ || rm -f $@
142 $(obj)/%.symtypes : $(src)/%.c FORCE
143 $(call cmd,cc_symtypes_c)
146 # Generate .ll files from .c
147 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
148 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
150 $(obj)/%.ll: $(src)/%.c FORCE
151 $(call if_changed_dep,cc_ll_c)
154 # The C file is compiled and updated dependency information is generated.
155 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
157 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
158 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
160 ifdef CONFIG_MODVERSIONS
161 # When module versioning is enabled the following steps are executed:
162 # o compile a <file>.o from <file>.c
163 # o if <file>.o doesn't contain a __ksymtab version, i.e. does
164 # not export symbols, it's done.
165 # o otherwise, we calculate symbol versions using the good old
166 # genksyms on the preprocessed source and postprocess them in a way
167 # that they are usable as a linker script
168 # o generate .tmp_<file>.o from <file>.o using the linker to
169 # replace the unresolved symbols __crc_exported_symbol with
170 # the actual value of the checksum generated by genksyms
171 # o remove .tmp_<file>.o to <file>.o
173 ifdef CONFIG_LTO_CLANG
174 # Generate .o.symversions files for each .o with exported symbols, and link these
175 # to the kernel and/or modules at the end.
176 cmd_modversions_c = \
177 if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
178 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
181 rm -f $@.symversions; \
184 cmd_modversions_c = \
185 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
186 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
187 > $(@D)/.tmp_$(@F:.o=.ver); \
189 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
190 -T $(@D)/.tmp_$(@F:.o=.ver); \
191 mv -f $(@D)/.tmp_$(@F) $@; \
192 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
197 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
198 # compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
199 ifdef BUILD_C_RECORDMCOUNT
200 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
201 RECORDMCOUNT_FLAGS = -w
203 # Due to recursion, we must skip empty.o.
204 # The empty.o file is created in the make process in order to determine
205 # the target endianness and word size. It is made before all other C
206 # files, including recordmcount.
207 sub_cmd_record_mcount = \
208 if [ $(@) != "scripts/mod/empty.o" ]; then \
209 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
211 recordmcount_source := $(srctree)/scripts/recordmcount.c \
212 $(srctree)/scripts/recordmcount.h
214 sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
215 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
216 "$(if $(CONFIG_64BIT),64,32)" \
217 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
218 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
219 "$(if $(part-of-module),1,0)" "$(@)";
220 recordmcount_source := $(srctree)/scripts/recordmcount.pl
221 endif # BUILD_C_RECORDMCOUNT
222 cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
223 $(sub_cmd_record_mcount))
224 endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
226 ifdef CONFIG_STACK_VALIDATION
227 ifndef CONFIG_LTO_CLANG
229 __objtool_obj := $(objtree)/tools/objtool/objtool
231 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
232 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
233 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
234 cmd_objtool = $(if $(patsubst y%,, \
235 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
236 $(__objtool_obj) $(objtool_args) $@)
237 objtool_obj = $(if $(patsubst y%,, \
238 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
241 endif # CONFIG_LTO_CLANG
242 endif # CONFIG_STACK_VALIDATION
244 # Rebuild all objects when objtool changes, or is enabled/disabled.
245 objtool_dep = $(objtool_obj) \
246 $(wildcard include/config/ORC_UNWINDER \
247 include/config/STACK_VALIDATION)
249 ifdef CONFIG_TRIM_UNUSED_KSYMS
251 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
253 # List module undefined symbols
254 undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
257 ifdef CONFIG_RETPOLINE
258 cmd_ubuntu_retpoline = $(CONFIG_SHELL) $(srctree)/scripts/ubuntu-retpoline-extract-one $(@) $(<) "$(filter -m16 %code16gcc.h,$(a_flags))";
260 cmd_ubuntu_retpoline =
264 $(call cmd_and_fixdep,cc_o_c)
265 $(call cmd,gen_ksymdeps)
269 $(call cmd,modversions_c)
270 $(call cmd,ubuntu-retpoline)
271 $(call cmd,record_mcount)
275 $(call cmd_and_fixdep,as_o_S)
276 $(call cmd,gen_ksymdeps)
278 $(call cmd,modversions_S)
279 $(call cmd,ubuntu-retpoline)
282 # Built-in and composite module parts
284 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
285 $(call if_changed_rule,cc_o_c)
286 $(call cmd,force_checksrc)
288 ifdef CONFIG_LTO_CLANG
289 # Module .o files may contain LLVM bitcode, compile them into native code
290 # before ELF processing
291 quiet_cmd_cc_lto_link_modules = LTO [M] $@
292 cmd_cc_lto_link_modules = \
293 $(LD) $(ld_flags) -r -o $@ \
294 $(shell [ -s $(@:.lto.o=.o.symversions) ] && \
295 echo -T $(@:.lto.o=.o.symversions)) \
296 --whole-archive $(filter-out FORCE,$^)
298 ifdef CONFIG_STACK_VALIDATION
299 # objtool was skipped for LLVM bitcode, run it now that we have compiled
300 # modules into native code
301 cmd_cc_lto_link_modules += ; \
302 $(objtree)/tools/objtool/objtool $(objtool_args) --module $@
305 $(obj)/%.lto.o: $(obj)/%.o FORCE
306 $(call if_changed,cc_lto_link_modules)
310 echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
311 $(undefined_syms) echo; \
314 $(obj)/%.mod: $(obj)/%$(mod-prelink-ext).o FORCE
315 $(call if_changed,mod)
317 quiet_cmd_cc_lst_c = MKLST $@
318 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
319 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
320 System.map $(OBJDUMP) > $@
322 $(obj)/%.lst: $(src)/%.c FORCE
323 $(call if_changed_dep,cc_lst_c)
325 # Compile assembler sources (.S)
326 # ---------------------------------------------------------------------------
328 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
329 # or a file that it includes, in order to get versioned symbols. We build a
330 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
331 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
333 # This is convoluted. The .S file must first be preprocessed to run guards and
334 # expand names, then the resulting exports must be constructed into plain
335 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
336 # to make the genksyms input.
338 # These mirror gensymtypes_c and co above, keep them in synch.
339 cmd_gensymtypes_S = \
340 { echo "\#include <linux/kernel.h>" ; \
341 echo "\#include <asm/asm-prototypes.h>" ; \
342 $(CPP) $(a_flags) $< | \
343 grep "\<___EXPORT_SYMBOL\>" | \
344 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
345 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
346 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
347 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
348 $(if $(KBUILD_PRESERVE),-p) \
349 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
351 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
352 cmd_cc_symtypes_S = \
353 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
354 test -s $@ || rm -f $@
356 $(obj)/%.symtypes : $(src)/%.S FORCE
357 $(call cmd,cc_symtypes_S)
360 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
361 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
363 $(obj)/%.s: $(src)/%.S FORCE
364 $(call if_changed_dep,cpp_s_S)
366 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
367 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
369 ifdef CONFIG_ASM_MODVERSIONS
371 # versioning matches the C process described above, with difference that
372 # we parse asm-prototypes.h C header to get function definitions.
374 cmd_modversions_S = \
375 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
376 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
377 > $(@D)/.tmp_$(@F:.o=.ver); \
379 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
380 -T $(@D)/.tmp_$(@F:.o=.ver); \
381 mv -f $(@D)/.tmp_$(@F) $@; \
382 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
386 $(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
387 $(call if_changed_rule,as_o_S)
389 targets += $(filter-out $(subdir-builtin), $(real-obj-y))
390 targets += $(filter-out $(subdir-modorder), $(real-obj-m))
391 targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
393 # Linker scripts preprocessor (.lds.S -> .lds)
394 # ---------------------------------------------------------------------------
395 quiet_cmd_cpp_lds_S = LDS $@
396 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
397 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
399 $(obj)/%.lds: $(src)/%.lds.S FORCE
400 $(call if_changed_dep,cpp_lds_S)
403 # ---------------------------------------------------------------------------
404 quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
405 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
406 $(basename $@).c $(basename $@).h
408 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
409 $(call cmd,asn1_compiler)
411 # Build the compiled-in targets
412 # ---------------------------------------------------------------------------
414 # To build objects in subdirs, we need to descend into the directories
415 $(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
416 $(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
418 # combine symversions for later processing
419 ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
420 cmd_update_lto_symversions = \
421 rm -f $@.symversions \
422 $(foreach n, $(filter-out FORCE,$^), \
423 $(if $(shell test -s $(n).symversions && echo y), \
424 ; cat $(n).symversions >> $@.symversions))
426 cmd_update_lto_symversions = echo >/dev/null
430 # Rule to compile a set of .o files into one .a file (without symbol table)
433 quiet_cmd_ar_builtin = AR $@
434 cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
436 quiet_cmd_ar_and_symver = AR $@
437 cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
439 $(obj)/built-in.a: $(real-obj-y) FORCE
440 $(call if_changed,ar_and_symver)
443 # Rule to create modules.order file
445 # Create commands to either record .ko file or cat modules.order from
447 # Add $(obj-m) as the prerequisite to avoid updating the timestamp of
448 # modules.order unless contained modules are updated.
450 cmd_modules_order = { $(foreach m, $(real-prereqs), \
451 $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
452 | $(AWK) '!x[$$0]++' - > $@
454 $(obj)/modules.order: $(obj-m) FORCE
455 $(call if_changed,modules_order)
458 # Rule to compile a set of .o files into one .a file (with symbol table)
460 quiet_cmd_ar_lib = AR $@
461 cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
463 $(obj)/lib.a: $(lib-y) FORCE
464 $(call if_changed,ar_lib)
467 # Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
468 # module is turned into a multi object module, $^ will contain header file
469 # dependencies recorded in the .*.cmd file.
470 ifdef CONFIG_LTO_CLANG
471 quiet_cmd_link_multi-m = AR [M] $@
473 $(cmd_update_lto_symversions); \
475 $(AR) cDPrsT $@ $(filter %.o,$^)
477 quiet_cmd_link_multi-m = LD [M] $@
478 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
481 $(multi-obj-m): FORCE
482 $(call if_changed,link_multi-m)
483 $(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
485 targets += $(multi-obj-m)
486 targets := $(filter-out $(PHONY), $(targets))
488 # Add intermediate targets:
489 # When building objects with specific suffix patterns, add intermediate
490 # targets that the final targets are derived from.
491 intermediate_targets = $(foreach sfx, $(2), \
492 $(patsubst %$(strip $(1)),%$(sfx), \
493 $(filter %$(strip $(1)), $(targets))))
494 # %.asn1.o <- %.asn1.[ch] <- %.asn1
495 # %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
496 # %.lex.o <- %.lex.c <- %.l
497 # %.tab.o <- %.tab.[ch] <- %.y
498 targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
499 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
500 $(call intermediate_targets, .lex.o, .lex.c) \
501 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
504 # ---------------------------------------------------------------------------
508 KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
510 curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
511 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
513 # Handle single targets without any rule: show "Nothing to be done for ..." or
514 # "No rule to make target ..." depending on whether the target exists.
515 unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
516 $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
518 single-subdirs := $(foreach d, $(subdir-ym), \
519 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
521 __build: $(curdir-single) $(single-subdirs)
522 ifneq ($(unknown-single),)
523 $(Q)$(MAKE) -f /dev/null $(unknown-single)
527 ifeq ($(curdir-single),)
528 # Nothing to do in this directory. Do not include any .*.cmd file for speed-up
531 targets += $(curdir-single)
536 __build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
537 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
538 $(subdir-ym) $(always-y)
544 # ---------------------------------------------------------------------------
546 PHONY += $(subdir-ym)
548 $(Q)$(MAKE) $(build)=$@ \
549 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
550 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
551 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
553 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
554 # ---------------------------------------------------------------------------
560 # Read all saved command lines and dependencies for the $(targets) we
561 # may be building above, using $(if_changed{,_dep}). As an
562 # optimization, we don't need to read them if the target does not
563 # exist, we will rebuild anyway in that case.
565 existing-targets := $(wildcard $(sort $(targets)))
567 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
569 # Create directories for object files if they do not exist
570 obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
571 # If targets exist, their directories apparently exist. Skip mkdir.
572 existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
573 obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
575 $(shell mkdir -p $(obj-dirs))