1 # ==========================================================================
3 # ==========================================================================
10 # Init all relevant variables used in kbuild files so
11 # 1) they have correct type
12 # 2) they do not inherit any value from the environment
33 # Read auto.conf if it exists, otherwise ignore
34 -include include/config/auto.conf
36 include scripts/Kbuild.include
38 # For backward compatibility check that these variables do not change
39 save-cflags := $(CFLAGS)
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 $(kbuild-file)
46 # If the save-* variables changed error out
47 ifeq ($(KBUILD_NOPEDANTIC),)
48 ifneq ("$(save-cflags)","$(CFLAGS)")
49 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
53 include scripts/Makefile.lib
56 ifneq ($(hostprogs-y),$(host-progs))
57 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
58 hostprogs-y += $(host-progs)
62 # Do not include host rules unless needed
63 ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
64 include scripts/Makefile.host
67 ifneq ($(KBUILD_SRC),)
68 # Create output directory if not already present
69 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
71 # Create directories for object files if directory does not exist
72 # Needed when obj-y := dir/file.o syntax is used
73 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
77 $(warning kbuild: Makefile.build is included improperly)
80 # ===========================================================================
82 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
83 lib-target := $(obj)/lib.a
84 obj-y += $(obj)/lib-ksyms.o
87 ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
88 builtin-target := $(obj)/built-in.o
91 modorder-target := $(obj)/modules.order
93 # We keep a list of all modules in $(MODVERDIR)
95 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
96 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
97 $(subdir-ym) $(always)
100 # Linus' kernel sanity checking tool
101 ifneq ($(KBUILD_CHECKSRC),0)
102 ifeq ($(KBUILD_CHECKSRC),2)
103 quiet_cmd_force_checksrc = CHECK $<
104 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
106 quiet_cmd_checksrc = CHECK $<
107 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
111 # Do section mismatch analysis for each module/built-in.o
112 ifdef CONFIG_DEBUG_SECTION_MISMATCH
113 cmd_secanalysis = ; scripts/mod/modpost $@
116 # Compile C sources (.c)
117 # ---------------------------------------------------------------------------
119 # Default is built-in, unless we know otherwise
121 $(if $(part-of-module), \
122 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
123 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
124 quiet_modtag := $(empty) $(empty)
126 $(real-objs-m) : part-of-module := y
127 $(real-objs-m:.o=.i) : part-of-module := y
128 $(real-objs-m:.o=.s) : part-of-module := y
129 $(real-objs-m:.o=.lst): part-of-module := y
131 $(real-objs-m) : quiet_modtag := [M]
132 $(real-objs-m:.o=.i) : quiet_modtag := [M]
133 $(real-objs-m:.o=.s) : quiet_modtag := [M]
134 $(real-objs-m:.o=.lst): quiet_modtag := [M]
136 $(obj-m) : quiet_modtag := [M]
138 # Default for not multi-part modules
139 modname = $(basetarget)
141 $(multi-objs-m) : modname = $(modname-multi)
142 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
143 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
144 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
145 $(multi-objs-y) : modname = $(modname-multi)
146 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
147 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
148 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
150 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
151 cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
153 $(obj)/%.s: $(src)/%.c FORCE
154 $(call if_changed_dep,cc_s_c)
156 quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
157 cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
159 $(obj)/%.i: $(src)/%.c FORCE
160 $(call if_changed_dep,cpp_i_c)
162 # These mirror gensymtypes_S and co below, keep them in synch.
163 cmd_gensymtypes_c = \
164 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
165 $(GENKSYMS) $(if $(1), -T $(2)) \
166 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
167 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
168 $(if $(KBUILD_PRESERVE),-p) \
169 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
171 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
172 cmd_cc_symtypes_c = \
174 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
175 test -s $@ || rm -f $@
177 $(obj)/%.symtypes : $(src)/%.c FORCE
178 $(call cmd,cc_symtypes_c)
181 # Generate .ll files from .c
182 quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
183 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
185 $(obj)/%.ll: $(src)/%.c FORCE
186 $(call if_changed_dep,cc_ll_c)
189 # The C file is compiled and updated dependency information is generated.
190 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
192 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
194 ifndef CONFIG_MODVERSIONS
195 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
198 # When module versioning is enabled the following steps are executed:
199 # o compile a .tmp_<file>.o from <file>.c
200 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
201 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
203 # o otherwise, we calculate symbol versions using the good old
204 # genksyms on the preprocessed source and postprocess them in a way
205 # that they are usable as a linker script
206 # o generate <file>.o from .tmp_<file>.o using the linker to
207 # replace the unresolved symbols __crc_exported_symbol with
208 # the actual value of the checksum generated by genksyms
210 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
212 cmd_modversions_c = \
213 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
214 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
215 > $(@D)/.tmp_$(@F:.o=.ver); \
217 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
218 -T $(@D)/.tmp_$(@F:.o=.ver); \
219 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
221 mv -f $(@D)/.tmp_$(@F) $@; \
225 ifdef CONFIG_FTRACE_MCOUNT_RECORD
226 ifdef BUILD_C_RECORDMCOUNT
227 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
228 RECORDMCOUNT_FLAGS = -w
230 # Due to recursion, we must skip empty.o.
231 # The empty.o file is created in the make process in order to determine
232 # the target endianness and word size. It is made before all other C
233 # files, including recordmcount.
234 sub_cmd_record_mcount = \
235 if [ $(@) != "scripts/mod/empty.o" ]; then \
236 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
238 recordmcount_source := $(srctree)/scripts/recordmcount.c \
239 $(srctree)/scripts/recordmcount.h
241 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
242 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
243 "$(if $(CONFIG_64BIT),64,32)" \
244 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
245 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
246 "$(if $(part-of-module),1,0)" "$(@)";
247 recordmcount_source := $(srctree)/scripts/recordmcount.pl
249 cmd_record_mcount = \
250 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
251 "$(CC_FLAGS_FTRACE)" ]; then \
252 $(sub_cmd_record_mcount) \
256 ifdef CONFIG_STACK_VALIDATION
257 ifneq ($(SKIP_STACK_VALIDATION),1)
259 __objtool_obj := $(objtree)/tools/objtool/objtool
262 ifndef CONFIG_FRAME_POINTER
263 objtool_args += --no-fp
266 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
267 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
268 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
269 cmd_objtool = $(if $(patsubst y%,, \
270 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
271 $(__objtool_obj) $(objtool_args) "$(@)";)
272 objtool_obj = $(if $(patsubst y%,, \
273 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
276 endif # SKIP_STACK_VALIDATION
277 endif # CONFIG_STACK_VALIDATION
280 $(call echo-cmd,checksrc) $(cmd_checksrc) \
281 $(call cmd_and_fixdep,cc_o_c) \
282 $(cmd_modversions_c) \
283 $(call echo-cmd,objtool) $(cmd_objtool) \
284 $(call echo-cmd,record_mcount) $(cmd_record_mcount)
288 $(call cmd_and_fixdep,as_o_S) \
289 $(cmd_modversions_S) \
290 $(call echo-cmd,objtool) $(cmd_objtool)
293 # List module undefined symbols (or empty line if not enabled)
294 ifdef CONFIG_TRIM_UNUSED_KSYMS
295 cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
297 cmd_undef_syms = echo
300 # Built-in and composite module parts
301 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
302 $(call cmd,force_checksrc)
303 $(call if_changed_rule,cc_o_c)
305 # Single-part modules are special since we need to mark them in $(MODVERDIR)
307 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
308 $(call cmd,force_checksrc)
309 $(call if_changed_rule,cc_o_c)
310 @{ echo $(@:.o=.ko); echo $@; \
311 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
313 quiet_cmd_cc_lst_c = MKLST $@
314 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
315 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
316 System.map $(OBJDUMP) > $@
318 $(obj)/%.lst: $(src)/%.c FORCE
319 $(call if_changed_dep,cc_lst_c)
321 # Compile assembler sources (.S)
322 # ---------------------------------------------------------------------------
324 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
326 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
327 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
329 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
330 # or a file that it includes, in order to get versioned symbols. We build a
331 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
332 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
334 # This is convoluted. The .S file must first be preprocessed to run guards and
335 # expand names, then the resulting exports must be constructed into plain
336 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
337 # to make the genksyms input.
339 # These mirror gensymtypes_c and co above, keep them in synch.
340 cmd_gensymtypes_S = \
341 (echo "\#include <linux/kernel.h>" ; \
342 echo "\#include <asm/asm-prototypes.h>" ; \
343 $(CPP) $(a_flags) $< | \
344 grep "\<___EXPORT_SYMBOL\>" | \
345 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
346 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
347 $(GENKSYMS) $(if $(1), -T $(2)) \
348 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
349 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
350 $(if $(KBUILD_PRESERVE),-p) \
351 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
353 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
354 cmd_cc_symtypes_S = \
356 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
357 test -s $@ || rm -f $@
359 $(obj)/%.symtypes : $(src)/%.S FORCE
360 $(call cmd,cc_symtypes_S)
363 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
364 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
366 $(obj)/%.s: $(src)/%.S FORCE
367 $(call if_changed_dep,cpp_s_S)
369 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
371 ifndef CONFIG_MODVERSIONS
372 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
376 ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
378 ifeq ($(ASM_PROTOTYPES),)
379 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
383 # versioning matches the C process described above, with difference that
384 # we parse asm-prototypes.h C header to get function definitions.
386 cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
388 cmd_modversions_S = \
389 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
390 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
391 > $(@D)/.tmp_$(@F:.o=.ver); \
393 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
394 -T $(@D)/.tmp_$(@F:.o=.ver); \
395 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
397 mv -f $(@D)/.tmp_$(@F) $@; \
402 $(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE
403 $(call if_changed_rule,as_o_S)
405 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
406 targets += $(extra-y) $(MAKECMDGOALS) $(always)
408 # Linker scripts preprocessor (.lds.S -> .lds)
409 # ---------------------------------------------------------------------------
410 quiet_cmd_cpp_lds_S = LDS $@
411 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
412 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
414 $(obj)/%.lds: $(src)/%.lds.S FORCE
415 $(call if_changed_dep,cpp_lds_S)
418 # ---------------------------------------------------------------------------
419 quiet_cmd_asn1_compiler = ASN.1 $@
420 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
421 $(subst .h,.c,$@) $(subst .c,.h,$@)
423 .PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
425 $(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
426 $(call cmd,asn1_compiler)
428 # Build the compiled-in targets
429 # ---------------------------------------------------------------------------
431 # To build objects in subdirs, we need to descend into the directories
432 $(sort $(subdir-obj-y)): $(subdir-ym) ;
435 # Rule to compile a set of .o files into one .o file
439 ifdef CONFIG_THIN_ARCHIVES
440 cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
441 cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
442 quiet_cmd_link_o_target = AR $@
444 cmd_make_builtin = $(LD) $(ld_flags) -r -o
445 cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
446 quiet_cmd_link_o_target = LD $@
449 # If the list of objects to link is empty, just create an empty built-in.o
450 cmd_link_o_target = $(if $(strip $(obj-y)),\
451 $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
453 $(cmd_make_empty_builtin) $@)
455 $(builtin-target): $(obj-y) FORCE
456 $(call if_changed,link_o_target)
458 targets += $(builtin-target)
459 endif # builtin-target
462 # Rule to create modules.order file
464 # Create commands to either record .ko file or cat modules.order from
467 $(foreach m, $(modorder), \
468 $(if $(filter %/modules.order, $m), \
469 cat $m;, echo kernel/$m;))
471 $(modorder-target): $(subdir-ym) FORCE
472 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
475 # Rule to compile a set of .o files into one .a file
478 quiet_cmd_link_l_target = AR $@
480 ifdef CONFIG_THIN_ARCHIVES
481 cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y)
483 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
486 $(lib-target): $(lib-y) FORCE
487 $(call if_changed,link_l_target)
489 targets += $(lib-target)
491 dummy-object = $(obj)/.lib_exports.o
492 ksyms-lds = $(dot-target).lds
493 ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
494 ref_prefix = EXTERN(_
499 quiet_cmd_export_list = EXPORTS $@
500 cmd_export_list = $(OBJDUMP) -h $< | \
501 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
502 rm -f $(dummy-object);\
503 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
504 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
505 rm $(dummy-object) $(ksyms-lds)
507 $(obj)/lib-ksyms.o: $(lib-target) FORCE
508 $(call if_changed,export_list)
510 targets += $(obj)/lib-ksyms.o
515 # Rule to link composite objects
517 # Composite objects are specified in kbuild makefile as follows:
518 # <composite-object>-objs := <list of .o files>
520 # <composite-object>-y := <list of .o files>
522 # <composite-object>-m := <list of .o files>
523 # The -m syntax only works if <composite object> is a module
525 $(filter $(addprefix $(obj)/, \
526 $($(subst $(obj)/,,$(@:.o=-objs))) \
527 $($(subst $(obj)/,,$(@:.o=-y))) \
528 $($(subst $(obj)/,,$(@:.o=-m)))), $^)
530 cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
532 ifdef CONFIG_THIN_ARCHIVES
533 quiet_cmd_link_multi-y = AR $@
534 cmd_link_multi-y = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
536 quiet_cmd_link_multi-y = LD $@
537 cmd_link_multi-y = $(cmd_link_multi-link)
540 quiet_cmd_link_multi-m = LD [M] $@
541 cmd_link_multi-m = $(cmd_link_multi-link)
543 $(multi-used-y): FORCE
544 $(call if_changed,link_multi-y)
545 $(call multi_depend, $(multi-used-y), .o, -objs -y)
547 $(multi-used-m): FORCE
548 $(call if_changed,link_multi-m)
549 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \
550 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
551 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
553 targets += $(multi-used-y) $(multi-used-m)
557 # ---------------------------------------------------------------------------
559 PHONY += $(subdir-ym)
561 $(Q)$(MAKE) $(build)=$@
563 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
564 # ---------------------------------------------------------------------------
570 # Read all saved command lines and dependencies for the $(targets) we
571 # may be building above, using $(if_changed{,_dep}). As an
572 # optimization, we don't need to read them if the target does not
573 # exist, we will rebuild anyway in that case.
575 targets := $(wildcard $(sort $(targets)))
576 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
578 ifneq ($(cmd_files),)
582 # Declare the contents of the .PHONY variable as phony. We keep that
583 # information in a variable se we can use it in if_changed and friends.