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 $(warning kbuild: Makefile.build is included improperly)
129 # ===========================================================================
131 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
132 lib-target := $(obj)/lib.a
135 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
136 builtin-target := $(obj)/built-in.o
139 modorder-target := $(obj)/modules.order
141 # We keep a list of all modules in $(MODVERDIR)
143 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
144 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
145 $(subdir-ym) $(always)
148 # Linus' kernel sanity checking tool
149 ifneq ($(KBUILD_CHECKSRC),0)
150 ifeq ($(KBUILD_CHECKSRC),2)
151 quiet_cmd_force_checksrc = CHECK $<
152 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
154 quiet_cmd_checksrc = CHECK $<
155 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
159 # Do section mismatch analysis for each module/built-in.o
160 ifdef CONFIG_DEBUG_SECTION_MISMATCH
161 cmd_secanalysis = ; scripts/mod/modpost $@
164 # Compile C sources (.c)
165 # ---------------------------------------------------------------------------
167 # Default is built-in, unless we know otherwise
169 $(if $(part-of-module), \
170 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
171 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
172 quiet_modtag := $(empty) $(empty)
174 $(real-objs-m) : part-of-module := y
175 $(real-objs-m:.o=.i) : part-of-module := y
176 $(real-objs-m:.o=.s) : part-of-module := y
177 $(real-objs-m:.o=.lst): part-of-module := y
179 $(real-objs-m) : quiet_modtag := [M]
180 $(real-objs-m:.o=.i) : quiet_modtag := [M]
181 $(real-objs-m:.o=.s) : quiet_modtag := [M]
182 $(real-objs-m:.o=.lst): quiet_modtag := [M]
184 $(obj-m) : quiet_modtag := [M]
186 # Default for not multi-part modules
187 modname = $(basetarget)
189 $(multi-objs-m) : modname = $(modname-multi)
190 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
191 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
192 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
193 $(multi-objs-y) : modname = $(modname-multi)
194 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
195 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
196 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
198 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
199 cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
201 $(obj)/%.s: $(src)/%.c FORCE
202 $(call if_changed_dep,cc_s_c)
204 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
205 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
207 $(obj)/%.i: $(src)/%.c FORCE
208 $(call if_changed_dep,cc_i_c)
211 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
212 $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
213 $(if $(KBUILD_PRESERVE),-p) \
214 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
216 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
217 cmd_cc_symtypes_c = \
219 $(call cmd_gensymtypes,true,$@) >/dev/null; \
220 test -s $@ || rm -f $@
222 $(obj)/%.symtypes : $(src)/%.c FORCE
223 $(call cmd,cc_symtypes_c)
226 # The C file is compiled and updated dependency information is generated.
227 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
229 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
231 ifndef CONFIG_MODVERSIONS
232 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
235 # When module versioning is enabled the following steps are executed:
236 # o compile a .tmp_<file>.o from <file>.c
237 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
238 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
240 # o otherwise, we calculate symbol versions using the good old
241 # genksyms on the preprocessed source and postprocess them in a way
242 # that they are usable as a linker script
243 # o generate <file>.o from .tmp_<file>.o using the linker to
244 # replace the unresolved symbols __crc_exported_symbol with
245 # the actual value of the checksum generated by genksyms
247 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
249 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
250 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
251 > $(@D)/.tmp_$(@F:.o=.ver); \
253 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
254 -T $(@D)/.tmp_$(@F:.o=.ver); \
255 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
257 mv -f $(@D)/.tmp_$(@F) $@; \
261 ifdef CONFIG_FTRACE_MCOUNT_RECORD
262 ifdef BUILD_C_RECORDMCOUNT
263 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
264 RECORDMCOUNT_FLAGS = -w
266 # Due to recursion, we must skip empty.o.
267 # The empty.o file is created in the make process in order to determine
268 # the target endianness and word size. It is made before all other C
269 # files, including recordmcount.
270 sub_cmd_record_mcount = \
271 if [ $(@) != "scripts/mod/empty.o" ]; then \
272 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
274 recordmcount_source := $(srctree)/scripts/recordmcount.c \
275 $(srctree)/scripts/recordmcount.h
277 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
278 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
279 "$(if $(CONFIG_64BIT),64,32)" \
280 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
281 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
282 "$(if $(part-of-module),1,0)" "$(@)";
283 recordmcount_source := $(srctree)/scripts/recordmcount.pl
285 cmd_record_mcount = \
286 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
287 $(sub_cmd_record_mcount) \
292 $(call echo-cmd,checksrc) $(cmd_checksrc) \
293 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
295 $(call echo-cmd,record_mcount) \
296 $(cmd_record_mcount) \
297 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
300 mv -f $(dot-target).tmp $(dot-target).cmd
303 # Built-in and composite module parts
304 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
305 $(call cmd,force_checksrc)
306 $(call if_changed_rule,cc_o_c)
308 # Single-part modules are special since we need to mark them in $(MODVERDIR)
310 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
311 $(call cmd,force_checksrc)
312 $(call if_changed_rule,cc_o_c)
313 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
315 quiet_cmd_cc_lst_c = MKLST $@
316 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
317 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
318 System.map $(OBJDUMP) > $@
320 $(obj)/%.lst: $(src)/%.c FORCE
321 $(call if_changed_dep,cc_lst_c)
323 # Compile assembler sources (.S)
324 # ---------------------------------------------------------------------------
326 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
328 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
329 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
331 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
332 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
334 $(obj)/%.s: $(src)/%.S FORCE
335 $(call if_changed_dep,as_s_S)
337 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
338 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
340 $(obj)/%.o: $(src)/%.S FORCE
341 $(call if_changed_dep,as_o_S)
343 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
344 targets += $(extra-y) $(MAKECMDGOALS) $(always)
346 # Linker scripts preprocessor (.lds.S -> .lds)
347 # ---------------------------------------------------------------------------
348 quiet_cmd_cpp_lds_S = LDS $@
349 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
350 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
352 $(obj)/%.lds: $(src)/%.lds.S FORCE
353 $(call if_changed_dep,cpp_lds_S)
355 # Build the compiled-in targets
356 # ---------------------------------------------------------------------------
358 # To build objects in subdirs, we need to descend into the directories
359 $(sort $(subdir-obj-y)): $(subdir-ym) ;
362 # Rule to compile a set of .o files into one .o file
365 quiet_cmd_link_o_target = LD $@
366 # If the list of objects to link is empty, just create an empty built-in.o
367 cmd_link_o_target = $(if $(strip $(obj-y)),\
368 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
370 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
372 $(builtin-target): $(obj-y) FORCE
373 $(call if_changed,link_o_target)
375 targets += $(builtin-target)
376 endif # builtin-target
379 # Rule to create modules.order file
381 # Create commands to either record .ko file or cat modules.order from
384 $(foreach m, $(modorder), \
385 $(if $(filter %/modules.order, $m), \
386 cat $m;, echo kernel/$m;))
388 $(modorder-target): $(subdir-ym) FORCE
389 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
392 # Rule to compile a set of .o files into one .a file
395 quiet_cmd_link_l_target = AR $@
396 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
398 $(lib-target): $(lib-y) FORCE
399 $(call if_changed,link_l_target)
401 targets += $(lib-target)
405 # Rule to link composite objects
407 # Composite objects are specified in kbuild makefile as follows:
408 # <composite-object>-objs := <list of .o files>
410 # <composite-object>-y := <list of .o files>
412 $(filter $(addprefix $(obj)/, \
413 $($(subst $(obj)/,,$(@:.o=-objs))) \
414 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
416 quiet_cmd_link_multi-y = LD $@
417 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
419 quiet_cmd_link_multi-m = LD [M] $@
420 cmd_link_multi-m = $(cmd_link_multi-y)
422 # We would rather have a list of rules like
424 # but that's not so easy, so we rather make all composite objects depend
425 # on the set of all their parts
426 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
427 $(call if_changed,link_multi-y)
429 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
430 $(call if_changed,link_multi-m)
431 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
433 targets += $(multi-used-y) $(multi-used-m)
437 # ---------------------------------------------------------------------------
439 PHONY += $(subdir-ym)
441 $(Q)$(MAKE) $(build)=$@
443 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
444 # ---------------------------------------------------------------------------
450 # Read all saved command lines and dependencies for the $(targets) we
451 # may be building above, using $(if_changed{,_dep}). As an
452 # optimization, we don't need to read them if the target does not
453 # exist, we will rebuild anyway in that case.
455 targets := $(wildcard $(sort $(targets)))
456 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
458 ifneq ($(cmd_files),)
462 # Declare the contents of the .PHONY variable as phony. We keep that
463 # information in a variable se we can use it in if_changed and friends.