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 EXTRA_CFLAGS)
56 # $(call cc-option... ) handles gcc -W.. options which
57 # are not supported by all versions of the compiler
58 ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS
59 KBUILD_EXTRA_WARNINGS := -Wextra
60 KBUILD_EXTRA_WARNINGS += -Wunused -Wno-unused-parameter
61 KBUILD_EXTRA_WARNINGS += -Waggregate-return
62 KBUILD_EXTRA_WARNINGS += -Wbad-function-cast
63 KBUILD_EXTRA_WARNINGS += -Wcast-qual
64 KBUILD_EXTRA_WARNINGS += -Wcast-align
65 KBUILD_EXTRA_WARNINGS += -Wconversion
66 KBUILD_EXTRA_WARNINGS += -Wdisabled-optimization
67 KBUILD_EXTRA_WARNINGS += -Wlogical-op
68 KBUILD_EXTRA_WARNINGS += -Wmissing-declarations
69 KBUILD_EXTRA_WARNINGS += -Wmissing-format-attribute
70 KBUILD_EXTRA_WARNINGS += $(call cc-option, -Wmissing-include-dirs,)
71 KBUILD_EXTRA_WARNINGS += -Wmissing-prototypes
72 KBUILD_EXTRA_WARNINGS += -Wnested-externs
73 KBUILD_EXTRA_WARNINGS += -Wold-style-definition
74 KBUILD_EXTRA_WARNINGS += $(call cc-option, -Woverlength-strings,)
75 KBUILD_EXTRA_WARNINGS += -Wpacked
76 KBUILD_EXTRA_WARNINGS += -Wpacked-bitfield-compat
77 KBUILD_EXTRA_WARNINGS += -Wpadded
78 KBUILD_EXTRA_WARNINGS += -Wpointer-arith
79 KBUILD_EXTRA_WARNINGS += -Wredundant-decls
80 KBUILD_EXTRA_WARNINGS += -Wshadow
81 KBUILD_EXTRA_WARNINGS += -Wswitch-default
82 KBUILD_EXTRA_WARNINGS += $(call cc-option, -Wvla,)
83 KBUILD_CFLAGS += $(KBUILD_EXTRA_WARNINGS)
86 include scripts/Makefile.lib
89 ifneq ($(hostprogs-y),$(host-progs))
90 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
91 hostprogs-y += $(host-progs)
95 # Do not include host rules unless needed
96 ifneq ($(hostprogs-y)$(hostprogs-m),)
97 include scripts/Makefile.host
100 ifneq ($(KBUILD_SRC),)
101 # Create output directory if not already present
102 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
104 # Create directories for object files if directory does not exist
105 # Needed when obj-y := dir/file.o syntax is used
106 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
110 $(warning kbuild: Makefile.build is included improperly)
113 # ===========================================================================
115 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
116 lib-target := $(obj)/lib.a
119 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
120 builtin-target := $(obj)/built-in.o
123 modorder-target := $(obj)/modules.order
125 # We keep a list of all modules in $(MODVERDIR)
127 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
128 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
129 $(subdir-ym) $(always)
132 # Linus' kernel sanity checking tool
133 ifneq ($(KBUILD_CHECKSRC),0)
134 ifeq ($(KBUILD_CHECKSRC),2)
135 quiet_cmd_force_checksrc = CHECK $<
136 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
138 quiet_cmd_checksrc = CHECK $<
139 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
143 # Do section mismatch analysis for each module/built-in.o
144 ifdef CONFIG_DEBUG_SECTION_MISMATCH
145 cmd_secanalysis = ; scripts/mod/modpost $@
148 # Compile C sources (.c)
149 # ---------------------------------------------------------------------------
151 # Default is built-in, unless we know otherwise
153 $(if $(part-of-module), \
154 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
155 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
156 quiet_modtag := $(empty) $(empty)
158 $(real-objs-m) : part-of-module := y
159 $(real-objs-m:.o=.i) : part-of-module := y
160 $(real-objs-m:.o=.s) : part-of-module := y
161 $(real-objs-m:.o=.lst): part-of-module := y
163 $(real-objs-m) : quiet_modtag := [M]
164 $(real-objs-m:.o=.i) : quiet_modtag := [M]
165 $(real-objs-m:.o=.s) : quiet_modtag := [M]
166 $(real-objs-m:.o=.lst): quiet_modtag := [M]
168 $(obj-m) : quiet_modtag := [M]
170 # Default for not multi-part modules
171 modname = $(basetarget)
173 $(multi-objs-m) : modname = $(modname-multi)
174 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
175 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
176 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
177 $(multi-objs-y) : modname = $(modname-multi)
178 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
179 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
180 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
182 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
183 cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
185 $(obj)/%.s: $(src)/%.c FORCE
186 $(call if_changed_dep,cc_s_c)
188 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
189 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
191 $(obj)/%.i: $(src)/%.c FORCE
192 $(call if_changed_dep,cc_i_c)
195 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
196 $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
197 $(if $(KBUILD_PRESERVE),-p) \
198 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
200 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
201 cmd_cc_symtypes_c = \
203 $(call cmd_gensymtypes,true,$@) >/dev/null; \
204 test -s $@ || rm -f $@
206 $(obj)/%.symtypes : $(src)/%.c FORCE
207 $(call cmd,cc_symtypes_c)
210 # The C file is compiled and updated dependency information is generated.
211 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
213 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
215 ifndef CONFIG_MODVERSIONS
216 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
219 # When module versioning is enabled the following steps are executed:
220 # o compile a .tmp_<file>.o from <file>.c
221 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
222 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
224 # o otherwise, we calculate symbol versions using the good old
225 # genksyms on the preprocessed source and postprocess them in a way
226 # that they are usable as a linker script
227 # o generate <file>.o from .tmp_<file>.o using the linker to
228 # replace the unresolved symbols __crc_exported_symbol with
229 # the actual value of the checksum generated by genksyms
231 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
233 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
234 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
235 > $(@D)/.tmp_$(@F:.o=.ver); \
237 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
238 -T $(@D)/.tmp_$(@F:.o=.ver); \
239 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
241 mv -f $(@D)/.tmp_$(@F) $@; \
245 ifdef CONFIG_FTRACE_MCOUNT_RECORD
246 ifdef BUILD_C_RECORDMCOUNT
247 # Due to recursion, we must skip empty.o.
248 # The empty.o file is created in the make process in order to determine
249 # the target endianness and word size. It is made before all other C
250 # files, including recordmcount.
251 sub_cmd_record_mcount = \
252 if [ $(@) != "scripts/mod/empty.o" ]; then \
253 $(objtree)/scripts/recordmcount "$(@)"; \
256 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
257 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
258 "$(if $(CONFIG_64BIT),64,32)" \
259 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
260 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
261 "$(if $(part-of-module),1,0)" "$(@)";
263 cmd_record_mcount = \
264 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
265 $(sub_cmd_record_mcount) \
270 $(call echo-cmd,checksrc) $(cmd_checksrc) \
271 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
273 $(call echo-cmd,record_mcount) \
274 $(cmd_record_mcount) \
275 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
278 mv -f $(dot-target).tmp $(dot-target).cmd
281 # Built-in and composite module parts
282 $(obj)/%.o: $(src)/%.c FORCE
283 $(call cmd,force_checksrc)
284 $(call if_changed_rule,cc_o_c)
286 # Single-part modules are special since we need to mark them in $(MODVERDIR)
288 $(single-used-m): $(obj)/%.o: $(src)/%.c FORCE
289 $(call cmd,force_checksrc)
290 $(call if_changed_rule,cc_o_c)
291 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
293 quiet_cmd_cc_lst_c = MKLST $@
294 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
295 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
296 System.map $(OBJDUMP) > $@
298 $(obj)/%.lst: $(src)/%.c FORCE
299 $(call if_changed_dep,cc_lst_c)
301 # Compile assembler sources (.S)
302 # ---------------------------------------------------------------------------
304 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
306 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
307 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
309 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
310 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
312 $(obj)/%.s: $(src)/%.S FORCE
313 $(call if_changed_dep,as_s_S)
315 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
316 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
318 $(obj)/%.o: $(src)/%.S FORCE
319 $(call if_changed_dep,as_o_S)
321 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
322 targets += $(extra-y) $(MAKECMDGOALS) $(always)
324 # Linker scripts preprocessor (.lds.S -> .lds)
325 # ---------------------------------------------------------------------------
326 quiet_cmd_cpp_lds_S = LDS $@
327 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
328 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
330 $(obj)/%.lds: $(src)/%.lds.S FORCE
331 $(call if_changed_dep,cpp_lds_S)
333 # Build the compiled-in targets
334 # ---------------------------------------------------------------------------
336 # To build objects in subdirs, we need to descend into the directories
337 $(sort $(subdir-obj-y)): $(subdir-ym) ;
340 # Rule to compile a set of .o files into one .o file
343 quiet_cmd_link_o_target = LD $@
344 # If the list of objects to link is empty, just create an empty built-in.o
345 cmd_link_o_target = $(if $(strip $(obj-y)),\
346 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
348 rm -f $@; $(AR) rcs $@)
350 $(builtin-target): $(obj-y) FORCE
351 $(call if_changed,link_o_target)
353 targets += $(builtin-target)
354 endif # builtin-target
357 # Rule to create modules.order file
359 # Create commands to either record .ko file or cat modules.order from
362 $(foreach m, $(modorder), \
363 $(if $(filter %/modules.order, $m), \
364 cat $m;, echo kernel/$m;))
366 $(modorder-target): $(subdir-ym) FORCE
367 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
370 # Rule to compile a set of .o files into one .a file
373 quiet_cmd_link_l_target = AR $@
374 cmd_link_l_target = rm -f $@; $(AR) rcs $@ $(lib-y)
376 $(lib-target): $(lib-y) FORCE
377 $(call if_changed,link_l_target)
379 targets += $(lib-target)
383 # Rule to link composite objects
385 # Composite objects are specified in kbuild makefile as follows:
386 # <composite-object>-objs := <list of .o files>
388 # <composite-object>-y := <list of .o files>
390 $(filter $(addprefix $(obj)/, \
391 $($(subst $(obj)/,,$(@:.o=-objs))) \
392 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
394 quiet_cmd_link_multi-y = LD $@
395 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
397 quiet_cmd_link_multi-m = LD [M] $@
398 cmd_link_multi-m = $(cmd_link_multi-y)
400 # We would rather have a list of rules like
402 # but that's not so easy, so we rather make all composite objects depend
403 # on the set of all their parts
404 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
405 $(call if_changed,link_multi-y)
407 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
408 $(call if_changed,link_multi-m)
409 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
411 targets += $(multi-used-y) $(multi-used-m)
415 # ---------------------------------------------------------------------------
417 PHONY += $(subdir-ym)
419 $(Q)$(MAKE) $(build)=$@
421 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
422 # ---------------------------------------------------------------------------
428 # Read all saved command lines and dependencies for the $(targets) we
429 # may be building above, using $(if_changed{,_dep}). As an
430 # optimization, we don't need to read them if the target does not
431 # exist, we will rebuild anyway in that case.
433 targets := $(wildcard $(sort $(targets)))
434 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
436 ifneq ($(cmd_files),)
440 # Declare the contents of the .PHONY variable as phony. We keep that
441 # information in a variable se we can use it in if_changed and friends.