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)
70 warning-2 := -Waggregate-return
71 warning-2 += -Wcast-align
72 warning-2 += -Wdisabled-optimization
73 warning-2 += -Wnested-externs
75 warning-2 += $(call cc-option, -Wlogical-op)
77 warning-3 := -Wbad-function-cast
78 warning-3 += -Wcast-qual
79 warning-3 += -Wconversion
82 warning-3 += -Wpointer-arith
83 warning-3 += -Wredundant-decls
84 warning-3 += -Wswitch-default
85 warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
86 warning-3 += $(call cc-option, -Wvla)
88 warning := $(warning-$(KBUILD_ENABLE_EXTRA_GCC_CHECKS))
90 ifeq ("$(warning)","")
91 $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
94 KBUILD_CFLAGS += $(warning)
97 include scripts/Makefile.lib
100 ifneq ($(hostprogs-y),$(host-progs))
101 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
102 hostprogs-y += $(host-progs)
106 # Do not include host rules unless needed
107 ifneq ($(hostprogs-y)$(hostprogs-m),)
108 include scripts/Makefile.host
111 ifneq ($(KBUILD_SRC),)
112 # Create output directory if not already present
113 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
115 # Create directories for object files if directory does not exist
116 # Needed when obj-y := dir/file.o syntax is used
117 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
121 $(warning kbuild: Makefile.build is included improperly)
124 # ===========================================================================
126 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
127 lib-target := $(obj)/lib.a
130 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
131 builtin-target := $(obj)/built-in.o
134 modorder-target := $(obj)/modules.order
136 # We keep a list of all modules in $(MODVERDIR)
138 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
139 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
140 $(subdir-ym) $(always)
143 # Linus' kernel sanity checking tool
144 ifneq ($(KBUILD_CHECKSRC),0)
145 ifeq ($(KBUILD_CHECKSRC),2)
146 quiet_cmd_force_checksrc = CHECK $<
147 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
149 quiet_cmd_checksrc = CHECK $<
150 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
154 # Do section mismatch analysis for each module/built-in.o
155 ifdef CONFIG_DEBUG_SECTION_MISMATCH
156 cmd_secanalysis = ; scripts/mod/modpost $@
159 # Compile C sources (.c)
160 # ---------------------------------------------------------------------------
162 # Default is built-in, unless we know otherwise
164 $(if $(part-of-module), \
165 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
166 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
167 quiet_modtag := $(empty) $(empty)
169 $(real-objs-m) : part-of-module := y
170 $(real-objs-m:.o=.i) : part-of-module := y
171 $(real-objs-m:.o=.s) : part-of-module := y
172 $(real-objs-m:.o=.lst): part-of-module := y
174 $(real-objs-m) : quiet_modtag := [M]
175 $(real-objs-m:.o=.i) : quiet_modtag := [M]
176 $(real-objs-m:.o=.s) : quiet_modtag := [M]
177 $(real-objs-m:.o=.lst): quiet_modtag := [M]
179 $(obj-m) : quiet_modtag := [M]
181 # Default for not multi-part modules
182 modname = $(basetarget)
184 $(multi-objs-m) : modname = $(modname-multi)
185 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
186 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
187 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
188 $(multi-objs-y) : modname = $(modname-multi)
189 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
190 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
191 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
193 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
194 cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
196 $(obj)/%.s: $(src)/%.c FORCE
197 $(call if_changed_dep,cc_s_c)
199 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
200 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
202 $(obj)/%.i: $(src)/%.c FORCE
203 $(call if_changed_dep,cc_i_c)
206 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
207 $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
208 $(if $(KBUILD_PRESERVE),-p) \
209 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
211 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
212 cmd_cc_symtypes_c = \
214 $(call cmd_gensymtypes,true,$@) >/dev/null; \
215 test -s $@ || rm -f $@
217 $(obj)/%.symtypes : $(src)/%.c FORCE
218 $(call cmd,cc_symtypes_c)
221 # The C file is compiled and updated dependency information is generated.
222 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
224 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
226 ifndef CONFIG_MODVERSIONS
227 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
230 # When module versioning is enabled the following steps are executed:
231 # o compile a .tmp_<file>.o from <file>.c
232 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
233 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
235 # o otherwise, we calculate symbol versions using the good old
236 # genksyms on the preprocessed source and postprocess them in a way
237 # that they are usable as a linker script
238 # o generate <file>.o from .tmp_<file>.o using the linker to
239 # replace the unresolved symbols __crc_exported_symbol with
240 # the actual value of the checksum generated by genksyms
242 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
244 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
245 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
246 > $(@D)/.tmp_$(@F:.o=.ver); \
248 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
249 -T $(@D)/.tmp_$(@F:.o=.ver); \
250 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
252 mv -f $(@D)/.tmp_$(@F) $@; \
256 ifdef CONFIG_FTRACE_MCOUNT_RECORD
257 ifdef BUILD_C_RECORDMCOUNT
258 # Due to recursion, we must skip empty.o.
259 # The empty.o file is created in the make process in order to determine
260 # the target endianness and word size. It is made before all other C
261 # files, including recordmcount.
262 sub_cmd_record_mcount = \
263 if [ $(@) != "scripts/mod/empty.o" ]; then \
264 $(objtree)/scripts/recordmcount "$(@)"; \
267 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
268 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
269 "$(if $(CONFIG_64BIT),64,32)" \
270 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
271 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
272 "$(if $(part-of-module),1,0)" "$(@)";
274 cmd_record_mcount = \
275 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
276 $(sub_cmd_record_mcount) \
281 $(call echo-cmd,checksrc) $(cmd_checksrc) \
282 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
284 $(call echo-cmd,record_mcount) \
285 $(cmd_record_mcount) \
286 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
289 mv -f $(dot-target).tmp $(dot-target).cmd
292 # Built-in and composite module parts
293 $(obj)/%.o: $(src)/%.c 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 FORCE
300 $(call cmd,force_checksrc)
301 $(call if_changed_rule,cc_o_c)
302 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
304 quiet_cmd_cc_lst_c = MKLST $@
305 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
306 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
307 System.map $(OBJDUMP) > $@
309 $(obj)/%.lst: $(src)/%.c FORCE
310 $(call if_changed_dep,cc_lst_c)
312 # Compile assembler sources (.S)
313 # ---------------------------------------------------------------------------
315 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
317 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
318 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
320 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
321 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
323 $(obj)/%.s: $(src)/%.S FORCE
324 $(call if_changed_dep,as_s_S)
326 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
327 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
329 $(obj)/%.o: $(src)/%.S FORCE
330 $(call if_changed_dep,as_o_S)
332 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
333 targets += $(extra-y) $(MAKECMDGOALS) $(always)
335 # Linker scripts preprocessor (.lds.S -> .lds)
336 # ---------------------------------------------------------------------------
337 quiet_cmd_cpp_lds_S = LDS $@
338 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
339 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
341 $(obj)/%.lds: $(src)/%.lds.S FORCE
342 $(call if_changed_dep,cpp_lds_S)
344 # Build the compiled-in targets
345 # ---------------------------------------------------------------------------
347 # To build objects in subdirs, we need to descend into the directories
348 $(sort $(subdir-obj-y)): $(subdir-ym) ;
351 # Rule to compile a set of .o files into one .o file
354 quiet_cmd_link_o_target = LD $@
355 # If the list of objects to link is empty, just create an empty built-in.o
356 cmd_link_o_target = $(if $(strip $(obj-y)),\
357 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
359 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
361 $(builtin-target): $(obj-y) FORCE
362 $(call if_changed,link_o_target)
364 targets += $(builtin-target)
365 endif # builtin-target
368 # Rule to create modules.order file
370 # Create commands to either record .ko file or cat modules.order from
373 $(foreach m, $(modorder), \
374 $(if $(filter %/modules.order, $m), \
375 cat $m;, echo kernel/$m;))
377 $(modorder-target): $(subdir-ym) FORCE
378 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
381 # Rule to compile a set of .o files into one .a file
384 quiet_cmd_link_l_target = AR $@
385 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
387 $(lib-target): $(lib-y) FORCE
388 $(call if_changed,link_l_target)
390 targets += $(lib-target)
394 # Rule to link composite objects
396 # Composite objects are specified in kbuild makefile as follows:
397 # <composite-object>-objs := <list of .o files>
399 # <composite-object>-y := <list of .o files>
401 $(filter $(addprefix $(obj)/, \
402 $($(subst $(obj)/,,$(@:.o=-objs))) \
403 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
405 quiet_cmd_link_multi-y = LD $@
406 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
408 quiet_cmd_link_multi-m = LD [M] $@
409 cmd_link_multi-m = $(cmd_link_multi-y)
411 # We would rather have a list of rules like
413 # but that's not so easy, so we rather make all composite objects depend
414 # on the set of all their parts
415 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
416 $(call if_changed,link_multi-y)
418 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
419 $(call if_changed,link_multi-m)
420 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
422 targets += $(multi-used-y) $(multi-used-m)
426 # ---------------------------------------------------------------------------
428 PHONY += $(subdir-ym)
430 $(Q)$(MAKE) $(build)=$@
432 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
433 # ---------------------------------------------------------------------------
439 # Read all saved command lines and dependencies for the $(targets) we
440 # may be building above, using $(if_changed{,_dep}). As an
441 # optimization, we don't need to read them if the target does not
442 # exist, we will rebuild anyway in that case.
444 targets := $(wildcard $(sort $(targets)))
445 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
447 ifneq ($(cmd_files),)
451 # Declare the contents of the .PHONY variable as phony. We keep that
452 # information in a variable se we can use it in if_changed and friends.