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)
72 warning-1 += $(call cc-disable-warning, missing-field-initializers)
74 warning-2 := -Waggregate-return
75 warning-2 += -Wcast-align
76 warning-2 += -Wdisabled-optimization
77 warning-2 += -Wnested-externs
79 warning-2 += $(call cc-option, -Wlogical-op)
80 warning-2 += $(call cc-option, -Wmissing-field-initializers)
82 warning-3 := -Wbad-function-cast
83 warning-3 += -Wcast-qual
84 warning-3 += -Wconversion
87 warning-3 += -Wpointer-arith
88 warning-3 += -Wredundant-decls
89 warning-3 += -Wswitch-default
90 warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
91 warning-3 += $(call cc-option, -Wvla)
93 warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
94 warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
95 warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
97 ifeq ("$(strip $(warning))","")
98 $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
101 KBUILD_CFLAGS += $(warning)
104 include scripts/Makefile.lib
107 ifneq ($(hostprogs-y),$(host-progs))
108 $(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
109 hostprogs-y += $(host-progs)
113 # Do not include host rules unless needed
114 ifneq ($(hostprogs-y)$(hostprogs-m),)
115 include scripts/Makefile.host
118 ifneq ($(KBUILD_SRC),)
119 # Create output directory if not already present
120 _dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
122 # Create directories for object files if directory does not exist
123 # Needed when obj-y := dir/file.o syntax is used
124 _dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
128 $(warning kbuild: Makefile.build is included improperly)
131 ifeq ($(CONFIG_XEN),y)
132 Makefile.xen := $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD),$(objtree)/scripts)/Makefile.xen
133 $(Makefile.xen): $(srctree)/scripts/Makefile.xen.awk $(srctree)/scripts/Makefile.build
135 $(if $(shell echo a | $(AWK) '{ print gensub(/a/, "AA", "g"); }'),\
136 ,$(error 'Your awk program does not define gensub. Use gawk or another awk with gensub'))
137 @$(AWK) -f $< $(filter-out $<,$^) >$@
139 xen-src-single-used-m := $(patsubst $(srctree)/%,%,$(wildcard $(addprefix $(srctree)/,$(single-used-m:.o=-xen.c))))
140 xen-single-used-m := $(xen-src-single-used-m:-xen.c=.o)
141 single-used-m := $(filter-out $(xen-single-used-m),$(single-used-m))
143 -include $(Makefile.xen)
146 # ===========================================================================
148 ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
149 lib-target := $(obj)/lib.a
152 ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
153 builtin-target := $(obj)/built-in.o
156 modorder-target := $(obj)/modules.order
158 # We keep a list of all modules in $(MODVERDIR)
160 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
161 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
162 $(subdir-ym) $(always)
165 # Linus' kernel sanity checking tool
166 ifneq ($(KBUILD_CHECKSRC),0)
167 ifeq ($(KBUILD_CHECKSRC),2)
168 quiet_cmd_force_checksrc = CHECK $<
169 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
171 quiet_cmd_checksrc = CHECK $<
172 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
176 # Do section mismatch analysis for each module/built-in.o
177 ifdef CONFIG_DEBUG_SECTION_MISMATCH
178 cmd_secanalysis = ; scripts/mod/modpost $@
181 # Compile C sources (.c)
182 # ---------------------------------------------------------------------------
184 # Default is built-in, unless we know otherwise
186 $(if $(part-of-module), \
187 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
188 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
189 quiet_modtag := $(empty) $(empty)
191 $(real-objs-m) : part-of-module := y
192 $(real-objs-m:.o=.i) : part-of-module := y
193 $(real-objs-m:.o=.s) : part-of-module := y
194 $(real-objs-m:.o=.lst): part-of-module := y
196 $(real-objs-m) : quiet_modtag := [M]
197 $(real-objs-m:.o=.i) : quiet_modtag := [M]
198 $(real-objs-m:.o=.s) : quiet_modtag := [M]
199 $(real-objs-m:.o=.lst): quiet_modtag := [M]
201 $(obj-m) : quiet_modtag := [M]
203 # Default for not multi-part modules
204 modname = $(basetarget)
206 $(multi-objs-m) : modname = $(modname-multi)
207 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
208 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
209 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
210 $(multi-objs-y) : modname = $(modname-multi)
211 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
212 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
213 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
215 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
216 cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
218 $(obj)/%.s: $(src)/%.c FORCE
219 $(call if_changed_dep,cc_s_c)
221 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
222 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
224 $(obj)/%.i: $(src)/%.c FORCE
225 $(call if_changed_dep,cc_i_c)
228 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
229 $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
230 $(if $(KBUILD_PRESERVE),-p) \
231 $(if $(KBUILD_OVERRIDE),-o) \
232 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
234 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
235 cmd_cc_symtypes_c = \
237 $(call cmd_gensymtypes,true,$@) >/dev/null; \
238 test -s $@ || rm -f $@
240 $(obj)/%.symtypes : $(src)/%.c FORCE
241 $(call cmd,cc_symtypes_c)
244 # The C file is compiled and updated dependency information is generated.
245 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
247 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
249 ifndef CONFIG_MODVERSIONS
250 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
253 # When module versioning is enabled the following steps are executed:
254 # o compile a .tmp_<file>.o from <file>.c
255 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
256 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
258 # o otherwise, we calculate symbol versions using the good old
259 # genksyms on the preprocessed source and postprocess them in a way
260 # that they are usable as a linker script
261 # o generate <file>.o from .tmp_<file>.o using the linker to
262 # replace the unresolved symbols __crc_exported_symbol with
263 # the actual value of the checksum generated by genksyms
265 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
267 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
268 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
269 > $(@D)/.tmp_$(@F:.o=.ver); \
271 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
272 -T $(@D)/.tmp_$(@F:.o=.ver); \
273 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
275 mv -f $(@D)/.tmp_$(@F) $@; \
279 ifdef CONFIG_FTRACE_MCOUNT_RECORD
280 ifdef BUILD_C_RECORDMCOUNT
281 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
282 RECORDMCOUNT_FLAGS = -w
284 # Due to recursion, we must skip empty.o.
285 # The empty.o file is created in the make process in order to determine
286 # the target endianness and word size. It is made before all other C
287 # files, including recordmcount.
288 sub_cmd_record_mcount = \
289 if [ $(@) != "scripts/mod/empty.o" ]; then \
290 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
292 recordmcount_source := $(srctree)/scripts/recordmcount.c \
293 $(srctree)/scripts/recordmcount.h
295 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
296 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
297 "$(if $(CONFIG_64BIT),64,32)" \
298 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
299 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
300 "$(if $(part-of-module),1,0)" "$(@)";
301 recordmcount_source := $(srctree)/scripts/recordmcount.pl
303 cmd_record_mcount = \
304 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
305 $(sub_cmd_record_mcount) \
310 $(call echo-cmd,checksrc) $(cmd_checksrc) \
311 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
313 $(call echo-cmd,record_mcount) \
314 $(cmd_record_mcount) \
315 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
318 mv -f $(dot-target).tmp $(dot-target).cmd
321 # Built-in and composite module parts
322 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
323 $(call cmd,force_checksrc)
324 $(call cmd,force_check_kmsg)
325 $(call if_changed_rule,cc_o_c)
327 # Single-part modules are special since we need to mark them in $(MODVERDIR)
329 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
330 $(call cmd,force_checksrc)
331 $(call cmd,force_check_kmsg)
332 $(call if_changed_rule,cc_o_c)
333 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
335 quiet_cmd_cc_lst_c = MKLST $@
336 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
337 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
338 System.map $(OBJDUMP) > $@
340 $(obj)/%.lst: $(src)/%.c FORCE
341 $(call if_changed_dep,cc_lst_c)
343 # Compile assembler sources (.S)
344 # ---------------------------------------------------------------------------
346 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
348 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
349 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
351 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
352 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
354 $(obj)/%.s: $(src)/%.S FORCE
355 $(call if_changed_dep,as_s_S)
357 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
358 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
360 $(obj)/%.o: $(src)/%.S FORCE
361 $(call if_changed_dep,as_o_S)
363 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
364 targets += $(extra-y) $(MAKECMDGOALS) $(always)
366 # Linker scripts preprocessor (.lds.S -> .lds)
367 # ---------------------------------------------------------------------------
368 quiet_cmd_cpp_lds_S = LDS $@
369 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
370 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
372 $(obj)/%.lds: $(src)/%.lds.S FORCE
373 $(call if_changed_dep,cpp_lds_S)
375 # Build the compiled-in targets
376 # ---------------------------------------------------------------------------
378 # To build objects in subdirs, we need to descend into the directories
379 $(sort $(subdir-obj-y)): $(subdir-ym) ;
382 # Rule to compile a set of .o files into one .o file
385 quiet_cmd_link_o_target = LD $@
386 # If the list of objects to link is empty, just create an empty built-in.o
387 cmd_link_o_target = $(if $(strip $(obj-y)),\
388 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
390 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
392 $(builtin-target): $(obj-y) FORCE
393 $(call if_changed,link_o_target)
395 targets += $(builtin-target)
396 endif # builtin-target
399 # Rule to create modules.order file
401 # Create commands to either record .ko file or cat modules.order from
404 $(foreach m, $(modorder), \
405 $(if $(filter %/modules.order, $m), \
406 cat $m;, echo kernel/$m;))
408 $(modorder-target): $(subdir-ym) FORCE
409 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
412 # Rule to compile a set of .o files into one .a file
415 quiet_cmd_link_l_target = AR $@
416 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
418 $(lib-target): $(lib-y) FORCE
419 $(call if_changed,link_l_target)
421 targets += $(lib-target)
425 # Rule to link composite objects
427 # Composite objects are specified in kbuild makefile as follows:
428 # <composite-object>-objs := <list of .o files>
430 # <composite-object>-y := <list of .o files>
432 $(filter $(addprefix $(obj)/, \
433 $($(subst $(obj)/,,$(@:.o=-objs))) \
434 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
436 quiet_cmd_link_multi-y = LD $@
437 cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
439 quiet_cmd_link_multi-m = LD [M] $@
440 cmd_link_multi-m = $(cmd_link_multi-y)
442 # We would rather have a list of rules like
444 # but that's not so easy, so we rather make all composite objects depend
445 # on the set of all their parts
446 $(multi-used-y) : %.o: $(multi-objs-y) FORCE
447 $(call if_changed,link_multi-y)
449 $(multi-used-m) : %.o: $(multi-objs-m) FORCE
450 $(call if_changed,link_multi-m)
451 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
453 targets += $(multi-used-y) $(multi-used-m)
456 ifneq ($(KBUILD_KMSG_CHECK),0)
457 ifeq ($(KBUILD_KMSG_CHECK),2)
459 quiet_cmd_force_check_kmsg = KMSG_PRINT $<
460 $(shell [ -d $(objtree)/man ] || mkdir -p $(objtree)/man)
463 quiet_cmd_force_check_kmsg = KMSG_CHECK $<
465 cmd_force_check_kmsg = $(KMSG_CHECK) $(kmsg_cmd) $(CC) $(c_flags) $< ;
469 # ---------------------------------------------------------------------------
471 PHONY += $(subdir-ym)
473 $(Q)$(MAKE) $(build)=$@
475 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
476 # ---------------------------------------------------------------------------
482 # Read all saved command lines and dependencies for the $(targets) we
483 # may be building above, using $(if_changed{,_dep}). As an
484 # optimization, we don't need to read them if the target does not
485 # exist, we will rebuild anyway in that case.
487 targets := $(wildcard $(sort $(targets)))
488 cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
490 ifneq ($(cmd_files),)
494 # Declare the contents of the .PHONY variable as phony. We keep that
495 # information in a variable se we can use it in if_changed and friends.