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)
56 # W=1 - warnings that may be relevant and does not occur too often
57 # W=2 - warnings that occur quite often but may still be relevant
58 # W=3 - the more obscure warnings, can most likely be ignored
60 # $(call cc-option, -W...) handles gcc -W.. options which
61 # are not supported by all versions of the compiler
62 ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS
65 warning-1 := -Wextra -Wunused -Wno-unused-parameter
66 warning-1 += -Wmissing-declarations
67 warning-1 += -Wmissing-format-attribute
68 warning-1 += -Wmissing-prototypes
69 warning-1 += -Wold-style-definition
70 warning-1 += $(call cc-option, -Wmissing-include-dirs)
71 warning-1 += $(call cc-option, -Wunused-but-set-variable)
73 warning-2 := -Waggregate-return
74 warning-2 += -Wcast-align
75 warning-2 += -Wdisabled-optimization
76 warning-2 += -Wnested-externs
78 warning-2 += $(call cc-option, -Wlogical-op)
80 warning-3 := -Wbad-function-cast
81 warning-3 += -Wcast-qual
82 warning-3 += -Wconversion
85 warning-3 += -Wpointer-arith
86 warning-3 += -Wredundant-decls
87 warning-3 += -Wswitch-default
88 warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
89 warning-3 += $(call cc-option, -Wvla)
91 warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
92 warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
93 warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
95 ifeq ("$(strip $(warning))","")
96 $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
99 KBUILD_CFLAGS += $(warning)
102 include scripts/Makefile.lib
105 ifneq ($(hostprogs-y),$(host-progs))
106 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
107 hostprogs-y += $(host-progs)
111 # Do not include host rules unless needed
112 ifneq ($(hostprogs-y)$(hostprogs-m),)
113 include scripts/Makefile.host
116 ifneq ($(KBUILD_SRC),)
117 # Create output directory if not already present
118 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
120 # Create directories for object files if directory does not exist
121 # Needed when obj-y := dir/file.o syntax is used
122 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
126 $(warning kbuild: Makefile.build is included improperly)
129 ifeq ($(CONFIG_XEN),y)
130 Makefile.xen := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD),$(objtree)/scripts)/Makefile.xen
131 $(Makefile.xen): $(srctree)/scripts/Makefile.xen.awk $(srctree)/scripts/Makefile.build
133 $(if $(shell echo a | $(AWK) '{ print gensub(/a/, "AA", "g"); }'),\
134 ,$(error 'Your awk program does not define gensub. Use gawk or another awk with gensub'))
135 @$(AWK) -f $< $(filter-out $<,$^) >$@
137 xen-src-single-used-m := $(patsubst $(srctree)/%,%,$(wildcard $(addprefix $(srctree)/,$(single-used-m:.o=-xen.c))))
138 xen-single-used-m := $(xen-src-single-used-m:-xen.c=.o)
139 single-used-m := $(filter-out $(xen-single-used-m),$(single-used-m))
141 -include $(Makefile.xen)
144 # ===========================================================================
146 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
147 lib-target := $(obj)/lib.a
150 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
151 builtin-target := $(obj)/built-in.o
154 modorder-target := $(obj)/modules.order
156 # We keep a list of all modules in $(MODVERDIR)
158 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
159 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
160 $(subdir-ym) $(always)
163 # Linus' kernel sanity checking tool
164 ifneq ($(KBUILD_CHECKSRC),0)
165 ifeq ($(KBUILD_CHECKSRC),2)
166 quiet_cmd_force_checksrc = CHECK $<
167 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
169 quiet_cmd_checksrc = CHECK $<
170 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
174 # Do section mismatch analysis for each module/built-in.o
175 ifdef CONFIG_DEBUG_SECTION_MISMATCH
176 cmd_secanalysis = ; scripts/mod/modpost $@
179 # Compile C sources (.c)
180 # ---------------------------------------------------------------------------
182 # Default is built-in, unless we know otherwise
184 $(if $(part-of-module), \
185 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
186 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
187 quiet_modtag := $(empty) $(empty)
189 $(real-objs-m) : part-of-module := y
190 $(real-objs-m:.o=.i) : part-of-module := y
191 $(real-objs-m:.o=.s) : part-of-module := y
192 $(real-objs-m:.o=.lst): part-of-module := y
194 $(real-objs-m) : quiet_modtag := [M]
195 $(real-objs-m:.o=.i) : quiet_modtag := [M]
196 $(real-objs-m:.o=.s) : quiet_modtag := [M]
197 $(real-objs-m:.o=.lst): quiet_modtag := [M]
199 $(obj-m) : quiet_modtag := [M]
201 # Default for not multi-part modules
202 modname = $(basetarget)
204 $(multi-objs-m) : modname = $(modname-multi)
205 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
206 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
207 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
208 $(multi-objs-y) : modname = $(modname-multi)
209 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
210 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
211 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
213 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
214 cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
216 $(obj)/%.s: $(src)/%.c FORCE
217 $(call if_changed_dep,cc_s_c)
219 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
220 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
222 $(obj)/%.i: $(src)/%.c FORCE
223 $(call if_changed_dep,cc_i_c)
226 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
227 $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
228 $(if $(KBUILD_PRESERVE),-p) \
229 $(if $(KBUILD_OVERRIDE),-o) \
230 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
232 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
233 cmd_cc_symtypes_c = \
235 $(call cmd_gensymtypes,true,$@) >/dev/null; \
236 test -s $@ || rm -f $@
238 $(obj)/%.symtypes : $(src)/%.c FORCE
239 $(call cmd,cc_symtypes_c)
242 # The C file is compiled and updated dependency information is generated.
243 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
245 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
247 ifndef CONFIG_MODVERSIONS
248 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
251 # When module versioning is enabled the following steps are executed:
252 # o compile a .tmp_<file>.o from <file>.c
253 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
254 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
256 # o otherwise, we calculate symbol versions using the good old
257 # genksyms on the preprocessed source and postprocess them in a way
258 # that they are usable as a linker script
259 # o generate <file>.o from .tmp_<file>.o using the linker to
260 # replace the unresolved symbols __crc_exported_symbol with
261 # the actual value of the checksum generated by genksyms
263 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
265 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
266 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
267 > $(@D)/.tmp_$(@F:.o=.ver); \
269 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
270 -T $(@D)/.tmp_$(@F:.o=.ver); \
271 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
273 mv -f $(@D)/.tmp_$(@F) $@; \
277 ifdef CONFIG_FTRACE_MCOUNT_RECORD
278 ifdef BUILD_C_RECORDMCOUNT
279 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
280 RECORDMCOUNT_FLAGS = -w
282 # Due to recursion, we must skip empty.o.
283 # The empty.o file is created in the make process in order to determine
284 # the target endianness and word size. It is made before all other C
285 # files, including recordmcount.
286 sub_cmd_record_mcount = \
287 if [ $(@) != "scripts/mod/empty.o" ]; then \
288 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
290 recordmcount_source := $(srctree)/scripts/recordmcount.c \
291 $(srctree)/scripts/recordmcount.h
293 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
294 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
295 "$(if $(CONFIG_64BIT),64,32)" \
296 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
297 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
298 "$(if $(part-of-module),1,0)" "$(@)";
299 recordmcount_source := $(srctree)/scripts/recordmcount.pl
301 cmd_record_mcount = \
302 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
303 $(sub_cmd_record_mcount) \
308 $(call echo-cmd,checksrc) $(cmd_checksrc) \
309 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
311 $(call echo-cmd,record_mcount) \
312 $(cmd_record_mcount) \
313 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
316 mv -f $(dot-target).tmp $(dot-target).cmd
319 # Built-in and composite module parts
320 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
321 $(call cmd,force_checksrc)
322 $(call cmd,force_check_kmsg)
323 $(call if_changed_rule,cc_o_c)
325 # Single-part modules are special since we need to mark them in $(MODVERDIR)
327 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
328 $(call cmd,force_checksrc)
329 $(call cmd,force_check_kmsg)
330 $(call if_changed_rule,cc_o_c)
331 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
333 quiet_cmd_cc_lst_c = MKLST $@
334 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
335 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
336 System.map $(OBJDUMP) > $@
338 $(obj)/%.lst: $(src)/%.c FORCE
339 $(call if_changed_dep,cc_lst_c)
341 # Compile assembler sources (.S)
342 # ---------------------------------------------------------------------------
344 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
346 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
347 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
349 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
350 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
352 $(obj)/%.s: $(src)/%.S FORCE
353 $(call if_changed_dep,as_s_S)
355 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
356 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
358 $(obj)/%.o: $(src)/%.S FORCE
359 $(call if_changed_dep,as_o_S)
361 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
362 targets += $(extra-y) $(MAKECMDGOALS) $(always)
364 # Linker scripts preprocessor (.lds.S -> .lds)
365 # ---------------------------------------------------------------------------
366 quiet_cmd_cpp_lds_S = LDS $@
367 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
368 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
370 $(obj)/%.lds: $(src)/%.lds.S FORCE
371 $(call if_changed_dep,cpp_lds_S)
373 # Build the compiled-in targets
374 # ---------------------------------------------------------------------------
376 # To build objects in subdirs, we need to descend into the directories
377 $(sort $(subdir-obj-y)): $(subdir-ym) ;
380 # Rule to compile a set of .o files into one .o file
383 quiet_cmd_link_o_target = LD $@
384 # If the list of objects to link is empty, just create an empty built-in.o
385 cmd_link_o_target = $(if $(strip $(obj-y)),\
386 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
388 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
390 $(builtin-target): $(obj-y) FORCE
391 $(call if_changed,link_o_target)
393 targets += $(builtin-target)
394 endif # builtin-target
397 # Rule to create modules.order file
399 # Create commands to either record .ko file or cat modules.order from
402 $(foreach m, $(modorder), \
403 $(if $(filter %/modules.order, $m), \
404 cat $m;, echo kernel/$m;))
406 $(modorder-target): $(subdir-ym) FORCE
407 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
410 # Rule to compile a set of .o files into one .a file
413 quiet_cmd_link_l_target = AR $@
414 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
416 $(lib-target): $(lib-y) FORCE
417 $(call if_changed,link_l_target)
419 targets += $(lib-target)
423 # Rule to link composite objects
425 # Composite objects are specified in kbuild makefile as follows:
426 # <composite-object>-objs := <list of .o files>
428 # <composite-object>-y := <list of .o files>
430 $(filter $(addprefix $(obj)/, \
431 $($(subst $(obj)/,,$(@:.o=-objs))) \
432 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
434 quiet_cmd_link_multi-y = LD $@
435 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
437 quiet_cmd_link_multi-m = LD [M] $@
438 cmd_link_multi-m = $(cmd_link_multi-y)
440 # We would rather have a list of rules like
442 # but that's not so easy, so we rather make all composite objects depend
443 # on the set of all their parts
444 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
445 $(call if_changed,link_multi-y)
447 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
448 $(call if_changed,link_multi-m)
449 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
451 targets += $(multi-used-y) $(multi-used-m)
454 ifneq ($(KBUILD_KMSG_CHECK),0)
455 ifeq ($(KBUILD_KMSG_CHECK),2)
457 quiet_cmd_force_check_kmsg = KMSG_PRINT $<
458 $(shell [ -d $(objtree)/man ] || mkdir -p $(objtree)/man)
461 quiet_cmd_force_check_kmsg = KMSG_CHECK $<
463 cmd_force_check_kmsg = $(KMSG_CHECK) $(kmsg_cmd) $(CC) $(c_flags) $< ;
467 # ---------------------------------------------------------------------------
469 PHONY += $(subdir-ym)
471 $(Q)$(MAKE) $(build)=$@
473 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
474 # ---------------------------------------------------------------------------
480 # Read all saved command lines and dependencies for the $(targets) we
481 # may be building above, using $(if_changed{,_dep}). As an
482 # optimization, we don't need to read them if the target does not
483 # exist, we will rebuild anyway in that case.
485 targets := $(wildcard $(sort $(targets)))
486 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
488 ifneq ($(cmd_files),)
492 # Declare the contents of the .PHONY variable as phony. We keep that
493 # information in a variable se we can use it in if_changed and friends.