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 # 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
63 warning-1 := -Wextra -Wunused -Wno-unused-parameter
64 warning-1 += -Wmissing-declarations
65 warning-1 += -Wmissing-format-attribute
66 warning-1 += -Wmissing-prototypes
67 warning-1 += -Wold-style-definition
68 warning-1 += $(call cc-option, -Wmissing-include-dirs)
69 warning-1 += $(call cc-option, -Wunused-but-set-variable)
71 warning-2 := -Waggregate-return
72 warning-2 += -Wcast-align
73 warning-2 += -Wdisabled-optimization
74 warning-2 += -Wnested-externs
76 warning-2 += $(call cc-option, -Wlogical-op)
78 warning-3 := -Wbad-function-cast
79 warning-3 += -Wcast-qual
80 warning-3 += -Wconversion
83 warning-3 += -Wpointer-arith
84 warning-3 += -Wredundant-decls
85 warning-3 += -Wswitch-default
86 warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
87 warning-3 += $(call cc-option, -Wvla)
89 warning := $(warning-$(KBUILD_ENABLE_EXTRA_GCC_CHECKS))
91 ifeq ("$(warning)","")
92 $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
95 KBUILD_CFLAGS += $(warning)
98 include scripts/Makefile.lib
101 ifneq ($(hostprogs-y),$(host-progs))
102 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
103 hostprogs-y += $(host-progs)
107 # Do not include host rules unless needed
108 ifneq ($(hostprogs-y)$(hostprogs-m),)
109 include scripts/Makefile.host
112 ifneq ($(KBUILD_SRC),)
113 # Create output directory if not already present
114 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
116 # Create directories for object files if directory does not exist
117 # Needed when obj-y := dir/file.o syntax is used
118 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
122 $(warning kbuild: Makefile.build is included improperly)
125 # ===========================================================================
127 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
128 lib-target := $(obj)/lib.a
131 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
132 builtin-target := $(obj)/built-in.o
135 modorder-target := $(obj)/modules.order
137 # We keep a list of all modules in $(MODVERDIR)
139 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
140 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
141 $(subdir-ym) $(always)
144 # Linus' kernel sanity checking tool
145 ifneq ($(KBUILD_CHECKSRC),0)
146 ifeq ($(KBUILD_CHECKSRC),2)
147 quiet_cmd_force_checksrc = CHECK $<
148 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
150 quiet_cmd_checksrc = CHECK $<
151 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
155 # Do section mismatch analysis for each module/built-in.o
156 ifdef CONFIG_DEBUG_SECTION_MISMATCH
157 cmd_secanalysis = ; scripts/mod/modpost $@
160 # Compile C sources (.c)
161 # ---------------------------------------------------------------------------
163 # Default is built-in, unless we know otherwise
165 $(if $(part-of-module), \
166 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
167 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
168 quiet_modtag := $(empty) $(empty)
170 $(real-objs-m) : part-of-module := y
171 $(real-objs-m:.o=.i) : part-of-module := y
172 $(real-objs-m:.o=.s) : part-of-module := y
173 $(real-objs-m:.o=.lst): part-of-module := y
175 $(real-objs-m) : quiet_modtag := [M]
176 $(real-objs-m:.o=.i) : quiet_modtag := [M]
177 $(real-objs-m:.o=.s) : quiet_modtag := [M]
178 $(real-objs-m:.o=.lst): quiet_modtag := [M]
180 $(obj-m) : quiet_modtag := [M]
182 # Default for not multi-part modules
183 modname = $(basetarget)
185 $(multi-objs-m) : modname = $(modname-multi)
186 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
187 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
188 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
189 $(multi-objs-y) : modname = $(modname-multi)
190 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
191 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
192 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
194 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
195 cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
197 $(obj)/%.s: $(src)/%.c FORCE
198 $(call if_changed_dep,cc_s_c)
200 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
201 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
203 $(obj)/%.i: $(src)/%.c FORCE
204 $(call if_changed_dep,cc_i_c)
207 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
208 $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
209 $(if $(KBUILD_PRESERVE),-p) \
210 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
212 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
213 cmd_cc_symtypes_c = \
215 $(call cmd_gensymtypes,true,$@) >/dev/null; \
216 test -s $@ || rm -f $@
218 $(obj)/%.symtypes : $(src)/%.c FORCE
219 $(call cmd,cc_symtypes_c)
222 # The C file is compiled and updated dependency information is generated.
223 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
225 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
227 ifndef CONFIG_MODVERSIONS
228 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
231 # When module versioning is enabled the following steps are executed:
232 # o compile a .tmp_<file>.o from <file>.c
233 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
234 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
236 # o otherwise, we calculate symbol versions using the good old
237 # genksyms on the preprocessed source and postprocess them in a way
238 # that they are usable as a linker script
239 # o generate <file>.o from .tmp_<file>.o using the linker to
240 # replace the unresolved symbols __crc_exported_symbol with
241 # the actual value of the checksum generated by genksyms
243 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
245 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
246 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
247 > $(@D)/.tmp_$(@F:.o=.ver); \
249 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
250 -T $(@D)/.tmp_$(@F:.o=.ver); \
251 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
253 mv -f $(@D)/.tmp_$(@F) $@; \
257 ifdef CONFIG_FTRACE_MCOUNT_RECORD
258 ifdef BUILD_C_RECORDMCOUNT
259 # Due to recursion, we must skip empty.o.
260 # The empty.o file is created in the make process in order to determine
261 # the target endianness and word size. It is made before all other C
262 # files, including recordmcount.
263 sub_cmd_record_mcount = \
264 if [ $(@) != "scripts/mod/empty.o" ]; then \
265 $(objtree)/scripts/recordmcount "$(@)"; \
268 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
269 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
270 "$(if $(CONFIG_64BIT),64,32)" \
271 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
272 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
273 "$(if $(part-of-module),1,0)" "$(@)";
275 cmd_record_mcount = \
276 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
277 $(sub_cmd_record_mcount) \
282 $(call echo-cmd,checksrc) $(cmd_checksrc) \
283 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
285 $(call echo-cmd,record_mcount) \
286 $(cmd_record_mcount) \
287 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
290 mv -f $(dot-target).tmp $(dot-target).cmd
293 # Built-in and composite module parts
294 $(obj)/%.o: $(src)/%.c FORCE
295 $(call cmd,force_checksrc)
296 $(call if_changed_rule,cc_o_c)
298 # Single-part modules are special since we need to mark them in $(MODVERDIR)
300 $(single-used-m): $(obj)/%.o: $(src)/%.c FORCE
301 $(call cmd,force_checksrc)
302 $(call if_changed_rule,cc_o_c)
303 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@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 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
322 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
324 $(obj)/%.s: $(src)/%.S FORCE
325 $(call if_changed_dep,as_s_S)
327 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
328 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
330 $(obj)/%.o: $(src)/%.S FORCE
331 $(call if_changed_dep,as_o_S)
333 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
334 targets += $(extra-y) $(MAKECMDGOALS) $(always)
336 # Linker scripts preprocessor (.lds.S -> .lds)
337 # ---------------------------------------------------------------------------
338 quiet_cmd_cpp_lds_S = LDS $@
339 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
340 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
342 $(obj)/%.lds: $(src)/%.lds.S FORCE
343 $(call if_changed_dep,cpp_lds_S)
345 # Build the compiled-in targets
346 # ---------------------------------------------------------------------------
348 # To build objects in subdirs, we need to descend into the directories
349 $(sort $(subdir-obj-y)): $(subdir-ym) ;
352 # Rule to compile a set of .o files into one .o file
355 quiet_cmd_link_o_target = LD $@
356 # If the list of objects to link is empty, just create an empty built-in.o
357 cmd_link_o_target = $(if $(strip $(obj-y)),\
358 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
360 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
362 $(builtin-target): $(obj-y) FORCE
363 $(call if_changed,link_o_target)
365 targets += $(builtin-target)
366 endif # builtin-target
369 # Rule to create modules.order file
371 # Create commands to either record .ko file or cat modules.order from
374 $(foreach m, $(modorder), \
375 $(if $(filter %/modules.order, $m), \
376 cat $m;, echo kernel/$m;))
378 $(modorder-target): $(subdir-ym) FORCE
379 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
382 # Rule to compile a set of .o files into one .a file
385 quiet_cmd_link_l_target = AR $@
386 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
388 $(lib-target): $(lib-y) FORCE
389 $(call if_changed,link_l_target)
391 targets += $(lib-target)
395 # Rule to link composite objects
397 # Composite objects are specified in kbuild makefile as follows:
398 # <composite-object>-objs := <list of .o files>
400 # <composite-object>-y := <list of .o files>
402 $(filter $(addprefix $(obj)/, \
403 $($(subst $(obj)/,,$(@:.o=-objs))) \
404 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
406 quiet_cmd_link_multi-y = LD $@
407 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
409 quiet_cmd_link_multi-m = LD [M] $@
410 cmd_link_multi-m = $(cmd_link_multi-y)
412 # We would rather have a list of rules like
414 # but that's not so easy, so we rather make all composite objects depend
415 # on the set of all their parts
416 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
417 $(call if_changed,link_multi-y)
419 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
420 $(call if_changed,link_multi-m)
421 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
423 targets += $(multi-used-y) $(multi-used-m)
427 # ---------------------------------------------------------------------------
429 PHONY += $(subdir-ym)
431 $(Q)$(MAKE) $(build)=$@
433 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
434 # ---------------------------------------------------------------------------
440 # Read all saved command lines and dependencies for the $(targets) we
441 # may be building above, using $(if_changed{,_dep}). As an
442 # optimization, we don't need to read them if the target does not
443 # exist, we will rebuild anyway in that case.
445 targets := $(wildcard $(sort $(targets)))
446 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
448 ifneq ($(cmd_files),)
452 # Declare the contents of the .PHONY variable as phony. We keep that
453 # information in a variable se we can use it in if_changed and friends.