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 # The C file is compiled and updated dependency information is generated.
182 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
184 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
186 ifndef CONFIG_MODVERSIONS
187 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
190 # When module versioning is enabled the following steps are executed:
191 # o compile a .tmp_<file>.o from <file>.c
192 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
193 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
195 # o otherwise, we calculate symbol versions using the good old
196 # genksyms on the preprocessed source and postprocess them in a way
197 # that they are usable as a linker script
198 # o generate <file>.o from .tmp_<file>.o using the linker to
199 # replace the unresolved symbols __crc_exported_symbol with
200 # the actual value of the checksum generated by genksyms
202 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
204 cmd_modversions_c = \
205 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
206 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
207 > $(@D)/.tmp_$(@F:.o=.ver); \
209 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
210 -T $(@D)/.tmp_$(@F:.o=.ver); \
211 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
213 mv -f $(@D)/.tmp_$(@F) $@; \
217 ifdef CONFIG_FTRACE_MCOUNT_RECORD
218 ifdef BUILD_C_RECORDMCOUNT
219 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
220 RECORDMCOUNT_FLAGS = -w
222 # Due to recursion, we must skip empty.o.
223 # The empty.o file is created in the make process in order to determine
224 # the target endianness and word size. It is made before all other C
225 # files, including recordmcount.
226 sub_cmd_record_mcount = \
227 if [ $(@) != "scripts/mod/empty.o" ]; then \
228 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
230 recordmcount_source := $(srctree)/scripts/recordmcount.c \
231 $(srctree)/scripts/recordmcount.h
233 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
234 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
235 "$(if $(CONFIG_64BIT),64,32)" \
236 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
237 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
238 "$(if $(part-of-module),1,0)" "$(@)";
239 recordmcount_source := $(srctree)/scripts/recordmcount.pl
241 cmd_record_mcount = \
242 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
243 "$(CC_FLAGS_FTRACE)" ]; then \
244 $(sub_cmd_record_mcount) \
248 ifdef CONFIG_STACK_VALIDATION
249 ifneq ($(SKIP_STACK_VALIDATION),1)
251 __objtool_obj := $(objtree)/tools/objtool/objtool
254 ifndef CONFIG_FRAME_POINTER
255 objtool_args += --no-fp
258 # 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
259 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
260 # 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
261 cmd_objtool = $(if $(patsubst y%,, \
262 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
263 $(__objtool_obj) $(objtool_args) "$(@)";)
264 objtool_obj = $(if $(patsubst y%,, \
265 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
268 endif # SKIP_STACK_VALIDATION
269 endif # CONFIG_STACK_VALIDATION
272 $(call echo-cmd,checksrc) $(cmd_checksrc) \
273 $(call cmd_and_fixdep,cc_o_c) \
274 $(cmd_modversions_c) \
276 $(call echo-cmd,record_mcount) $(cmd_record_mcount)
280 $(call cmd_and_fixdep,as_o_S) \
281 $(cmd_modversions_S) \
285 # List module undefined symbols (or empty line if not enabled)
286 ifdef CONFIG_TRIM_UNUSED_KSYMS
287 cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
289 cmd_undef_syms = echo
292 # Built-in and composite module parts
293 $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
294 $(call cmd,force_checksrc)
295 $(call if_changed_rule,cc_o_c)
297 # Single-part modules are special since we need to mark them in $(MODVERDIR)
299 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
300 $(call cmd,force_checksrc)
301 $(call if_changed_rule,cc_o_c)
302 @{ echo $(@:.o=.ko); echo $@; \
303 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
305 quiet_cmd_cc_lst_c = MKLST $@
306 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
307 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
308 System.map $(OBJDUMP) > $@
310 $(obj)/%.lst: $(src)/%.c FORCE
311 $(call if_changed_dep,cc_lst_c)
313 # Compile assembler sources (.S)
314 # ---------------------------------------------------------------------------
316 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
318 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
319 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
321 # .S file exports must have their C prototypes defined in asm/asm-prototypes.h
322 # or a file that it includes, in order to get versioned symbols. We build a
323 # dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
324 # the .S file (with trailing ';'), and run genksyms on that, to extract vers.
326 # This is convoluted. The .S file must first be preprocessed to run guards and
327 # expand names, then the resulting exports must be constructed into plain
328 # EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
329 # to make the genksyms input.
331 # These mirror gensymtypes_c and co above, keep them in synch.
332 cmd_gensymtypes_S = \
333 (echo "\#include <linux/kernel.h>" ; \
334 echo "\#include <asm/asm-prototypes.h>" ; \
335 $(CPP) $(a_flags) $< | \
336 grep "\<___EXPORT_SYMBOL\>" | \
337 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
338 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
339 $(GENKSYMS) $(if $(1), -T $(2)) \
340 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
341 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
342 $(if $(KBUILD_PRESERVE),-p) \
343 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
345 quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
346 cmd_cc_symtypes_S = \
348 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
349 test -s $@ || rm -f $@
351 $(obj)/%.symtypes : $(src)/%.S FORCE
352 $(call cmd,cc_symtypes_S)
355 quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
356 cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
358 $(obj)/%.s: $(src)/%.S FORCE
359 $(call if_changed_dep,cpp_s_S)
361 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
363 ifndef CONFIG_MODVERSIONS
364 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
368 ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
370 ifeq ($(ASM_PROTOTYPES),)
371 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
375 # versioning matches the C process described above, with difference that
376 # we parse asm-prototypes.h C header to get function definitions.
378 cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
380 cmd_modversions_S = \
381 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
382 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
383 > $(@D)/.tmp_$(@F:.o=.ver); \
385 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
386 -T $(@D)/.tmp_$(@F:.o=.ver); \
387 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
389 mv -f $(@D)/.tmp_$(@F) $@; \
394 $(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE
395 $(call if_changed_rule,as_o_S)
397 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
398 targets += $(extra-y) $(MAKECMDGOALS) $(always)
400 # Linker scripts preprocessor (.lds.S -> .lds)
401 # ---------------------------------------------------------------------------
402 quiet_cmd_cpp_lds_S = LDS $@
403 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
404 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
406 $(obj)/%.lds: $(src)/%.lds.S FORCE
407 $(call if_changed_dep,cpp_lds_S)
410 # ---------------------------------------------------------------------------
411 quiet_cmd_asn1_compiler = ASN.1 $@
412 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
413 $(subst .h,.c,$@) $(subst .c,.h,$@)
415 .PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
417 $(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
418 $(call cmd,asn1_compiler)
420 # Build the compiled-in targets
421 # ---------------------------------------------------------------------------
423 # To build objects in subdirs, we need to descend into the directories
424 $(sort $(subdir-obj-y)): $(subdir-ym) ;
427 # Rule to compile a set of .o files into one .o file
431 ifdef CONFIG_THIN_ARCHIVES
432 cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
433 cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
434 quiet_cmd_link_o_target = AR $@
436 cmd_make_builtin = $(LD) $(ld_flags) -r -o
437 cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
438 quiet_cmd_link_o_target = LD $@
441 # If the list of objects to link is empty, just create an empty built-in.o
442 cmd_link_o_target = $(if $(strip $(obj-y)),\
443 $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
445 $(cmd_make_empty_builtin) $@)
447 $(builtin-target): $(obj-y) FORCE
448 $(call if_changed,link_o_target)
450 targets += $(builtin-target)
451 endif # builtin-target
454 # Rule to create modules.order file
456 # Create commands to either record .ko file or cat modules.order from
459 $(foreach m, $(modorder), \
460 $(if $(filter %/modules.order, $m), \
461 cat $m;, echo kernel/$m;))
463 $(modorder-target): $(subdir-ym) FORCE
464 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
467 # Rule to compile a set of .o files into one .a file
470 quiet_cmd_link_l_target = AR $@
472 ifdef CONFIG_THIN_ARCHIVES
473 cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y)
475 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
478 $(lib-target): $(lib-y) FORCE
479 $(call if_changed,link_l_target)
481 targets += $(lib-target)
483 dummy-object = $(obj)/.lib_exports.o
484 ksyms-lds = $(dot-target).lds
485 ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
486 ref_prefix = EXTERN(_
491 quiet_cmd_export_list = EXPORTS $@
492 cmd_export_list = $(OBJDUMP) -h $< | \
493 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
494 rm -f $(dummy-object);\
495 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
496 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
497 rm $(dummy-object) $(ksyms-lds)
499 $(obj)/lib-ksyms.o: $(lib-target) FORCE
500 $(call if_changed,export_list)
502 targets += $(obj)/lib-ksyms.o
507 # Rule to link composite objects
509 # Composite objects are specified in kbuild makefile as follows:
510 # <composite-object>-objs := <list of .o files>
512 # <composite-object>-y := <list of .o files>
514 # <composite-object>-m := <list of .o files>
515 # The -m syntax only works if <composite object> is a module
517 $(filter $(addprefix $(obj)/, \
518 $($(subst $(obj)/,,$(@:.o=-objs))) \
519 $($(subst $(obj)/,,$(@:.o=-y))) \
520 $($(subst $(obj)/,,$(@:.o=-m)))), $^)
522 cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
524 ifdef CONFIG_THIN_ARCHIVES
525 quiet_cmd_link_multi-y = AR $@
526 cmd_link_multi-y = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
528 quiet_cmd_link_multi-y = LD $@
529 cmd_link_multi-y = $(cmd_link_multi-link)
532 quiet_cmd_link_multi-m = LD [M] $@
533 cmd_link_multi-m = $(cmd_link_multi-link)
535 $(multi-used-y): FORCE
536 $(call if_changed,link_multi-y)
537 $(call multi_depend, $(multi-used-y), .o, -objs -y)
539 $(multi-used-m): FORCE
540 $(call if_changed,link_multi-m)
541 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \
542 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
543 $(call multi_depend, $(multi-used-m), .o, -objs -y -m)
545 targets += $(multi-used-y) $(multi-used-m)
549 # ---------------------------------------------------------------------------
551 PHONY += $(subdir-ym)
553 $(Q)$(MAKE) $(build)=$@
555 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
556 # ---------------------------------------------------------------------------
562 # Read all saved command lines and dependencies for the $(targets) we
563 # may be building above, using $(if_changed{,_dep}). As an
564 # optimization, we don't need to read them if the target does not
565 # exist, we will rebuild anyway in that case.
567 targets := $(wildcard $(sort $(targets)))
568 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
570 ifneq ($(cmd_files),)
574 # Declare the contents of the .PHONY variable as phony. We keep that
575 # information in a variable se we can use it in if_changed and friends.