1 # SPDX-License-Identifier: GPL-2.0
2 # ==========================================================================
4 # ==========================================================================
8 src := $(patsubst $(prefix)/%,%,$(obj))
11 src := $(patsubst $(prefix)/%,%,$(obj))
20 # Init all relevant variables used in kbuild files so
21 # 1) they have correct type
22 # 2) they do not inherit any value from the environment
43 # Read auto.conf if it exists, otherwise ignore
45 -include include/config/auto.conf
46 -include $(prefix)/include/autoconf.mk
47 include scripts/Makefile.uncmd_spl
49 include scripts/Kbuild.include
51 # For backward compatibility check that these variables do not change
52 save-cflags := $(CFLAGS)
54 # The filename Kbuild has precedence over Makefile
55 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
56 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
57 include $(kbuild-file)
60 asflags-y += $(PLATFORM_CPPFLAGS)
61 ccflags-y += $(PLATFORM_CPPFLAGS)
62 cppflags-y += $(PLATFORM_CPPFLAGS)
64 # If the save-* variables changed error out
65 ifeq ($(KBUILD_NOPEDANTIC),)
66 ifneq ("$(save-cflags)","$(CFLAGS)")
67 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
71 include scripts/Makefile.lib
73 # Do not include host rules unless needed
74 ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
75 include scripts/Makefile.host
79 $(warning kbuild: Makefile.build is included improperly)
82 # ===========================================================================
84 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
85 lib-target := $(obj)/lib.a
88 ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
89 builtin-target := $(obj)/built-in.o
92 modorder-target := $(obj)/modules.order
94 # We keep a list of all modules in $(MODVERDIR)
96 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
97 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
98 $(subdir-ym) $(always)
101 # Linus' kernel sanity checking tool
102 ifneq ($(KBUILD_CHECKSRC),0)
103 ifeq ($(KBUILD_CHECKSRC),2)
104 quiet_cmd_force_checksrc = CHECK $<
105 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
107 quiet_cmd_checksrc = CHECK $<
108 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
112 # Do section mismatch analysis for each module/built-in.o
113 ifdef CONFIG_DEBUG_SECTION_MISMATCH
114 cmd_secanalysis = ; scripts/mod/modpost $@
117 # Compile C sources (.c)
118 # ---------------------------------------------------------------------------
120 # Default is built-in, unless we know otherwise
122 $(if $(part-of-module), \
123 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
124 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
125 quiet_modtag := $(empty) $(empty)
127 $(real-objs-m) : part-of-module := y
128 $(real-objs-m:.o=.i) : part-of-module := y
129 $(real-objs-m:.o=.s) : part-of-module := y
130 $(real-objs-m:.o=.lst): part-of-module := y
132 $(real-objs-m) : quiet_modtag := [M]
133 $(real-objs-m:.o=.i) : quiet_modtag := [M]
134 $(real-objs-m:.o=.s) : quiet_modtag := [M]
135 $(real-objs-m:.o=.lst): quiet_modtag := [M]
137 $(obj-m) : quiet_modtag := [M]
139 # Default for not multi-part modules
140 modname = $(basetarget)
142 $(multi-objs-m) : modname = $(modname-multi)
143 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
144 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
145 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
146 $(multi-objs-y) : modname = $(modname-multi)
147 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
148 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
149 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
151 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
152 cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
154 $(obj)/%.s: $(src)/%.c FORCE
155 $(call if_changed_dep,cc_s_c)
157 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
158 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
160 $(obj)/%.i: $(src)/%.c FORCE
161 $(call if_changed_dep,cc_i_c)
164 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
165 $(GENKSYMS) $(if $(1), -T $(2)) \
166 $(if $(KBUILD_PRESERVE),-p) \
167 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
169 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
170 cmd_cc_symtypes_c = \
172 $(call cmd_gensymtypes,true,$@) >/dev/null; \
173 test -s $@ || rm -f $@
175 $(obj)/%.symtypes : $(src)/%.c FORCE
176 $(call cmd,cc_symtypes_c)
179 # The C file is compiled and updated dependency information is generated.
180 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
182 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
184 ifndef CONFIG_MODVERSIONS
185 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
188 # When module versioning is enabled the following steps are executed:
189 # o compile a .tmp_<file>.o from <file>.c
190 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
191 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
193 # o otherwise, we calculate symbol versions using the good old
194 # genksyms on the preprocessed source and postprocess them in a way
195 # that they are usable as a linker script
196 # o generate <file>.o from .tmp_<file>.o using the linker to
197 # replace the unresolved symbols __crc_exported_symbol with
198 # the actual value of the checksum generated by genksyms
200 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
202 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
203 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
204 > $(@D)/.tmp_$(@F:.o=.ver); \
206 $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
207 -T $(@D)/.tmp_$(@F:.o=.ver); \
208 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
210 mv -f $(@D)/.tmp_$(@F) $@; \
214 ifdef CONFIG_FTRACE_MCOUNT_RECORD
215 # gcc 5 supports generating the mcount tables directly
216 ifneq ($(call cc-option,-mrecord-mcount,y),y)
217 KBUILD_CFLAGS += -mrecord-mcount
219 # else do it all manually
220 ifdef BUILD_C_RECORDMCOUNT
221 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
222 RECORDMCOUNT_FLAGS = -w
224 # Due to recursion, we must skip empty.o.
225 # The empty.o file is created in the make process in order to determine
226 # the target endianness and word size. It is made before all other C
227 # files, including recordmcount.
228 sub_cmd_record_mcount = \
229 if [ $(@) != "scripts/mod/empty.o" ]; then \
230 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
232 recordmcount_source := $(srctree)/scripts/recordmcount.c \
233 $(srctree)/scripts/recordmcount.h
235 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
236 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
237 "$(if $(CONFIG_64BIT),64,32)" \
238 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
239 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
240 "$(if $(part-of-module),1,0)" "$(@)";
241 recordmcount_source := $(srctree)/scripts/recordmcount.pl
243 cmd_record_mcount = \
244 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
245 "$(CC_FLAGS_FTRACE)" ]; then \
246 $(sub_cmd_record_mcount) \
248 endif # -record-mcount
252 $(call echo-cmd,checksrc) $(cmd_checksrc) \
253 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
255 $(call echo-cmd,record_mcount) \
256 $(cmd_record_mcount) \
257 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
260 mv -f $(dot-target).tmp $(dot-target).cmd
263 # Built-in and composite module parts
264 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
265 $(call cmd,force_checksrc)
266 $(call if_changed_rule,cc_o_c)
268 # Single-part modules are special since we need to mark them in $(MODVERDIR)
270 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
271 $(call cmd,force_checksrc)
272 $(call if_changed_rule,cc_o_c)
273 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
275 quiet_cmd_cc_lst_c = MKLST $@
276 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
277 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
278 System.map $(OBJDUMP) > $@
280 $(obj)/%.lst: $(src)/%.c FORCE
281 $(call if_changed_dep,cc_lst_c)
283 # Compile assembler sources (.S)
284 # ---------------------------------------------------------------------------
286 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
288 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
289 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
291 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
292 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
294 $(obj)/%.s: $(src)/%.S FORCE
295 $(call if_changed_dep,as_s_S)
297 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
298 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
300 $(obj)/%.o: $(src)/%.S FORCE
301 $(call if_changed_dep,as_o_S)
303 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
304 targets += $(extra-y) $(MAKECMDGOALS) $(always)
306 # Linker scripts preprocessor (.lds.S -> .lds)
307 # ---------------------------------------------------------------------------
308 quiet_cmd_cpp_lds_S = LDS $@
309 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
310 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
312 $(obj)/%.lds: $(src)/%.lds.S FORCE
313 $(call if_changed_dep,cpp_lds_S)
316 # ---------------------------------------------------------------------------
317 quiet_cmd_asn1_compiler = ASN.1 $@
318 cmd_asn1_compiler = $(objtree)/tools/asn1_compiler $< \
319 $(subst .h,.c,$@) $(subst .c,.h,$@)
321 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/tools/asn1_compiler
322 $(call cmd,asn1_compiler)
324 # Build the compiled-in targets
325 # ---------------------------------------------------------------------------
327 # To build objects in subdirs, we need to descend into the directories
328 $(sort $(subdir-obj-y)): $(subdir-ym) ;
331 # Rule to compile a set of .o files into one .o file
334 quiet_cmd_link_o_target = AR $@
335 # If the list of objects to link is empty, just create an empty built-in.o
336 cmd_link_o_target = $(if $(strip $(obj-y)),\
337 rm -f $@; $(AR) cDPrsT $@ $(filter $(obj-y), $^), \
338 rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@)
340 $(builtin-target): $(obj-y) FORCE
341 $(call if_changed,link_o_target)
343 targets += $(builtin-target)
344 endif # builtin-target
347 # Rule to create modules.order file
349 # Create commands to either record .ko file or cat modules.order from
352 $(foreach m, $(modorder), \
353 $(if $(filter %/modules.order, $m), \
354 cat $m;, echo kernel/$m;))
356 $(modorder-target): $(subdir-ym) FORCE
357 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
360 # Rule to compile a set of .o files into one .a file
363 quiet_cmd_link_l_target = AR $@
364 cmd_link_l_target = rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@ $(lib-y)
366 $(lib-target): $(lib-y) FORCE
367 $(call if_changed,link_l_target)
369 targets += $(lib-target)
373 # Rule to link composite objects
375 # Composite objects are specified in kbuild makefile as follows:
376 # <composite-object>-objs := <list of .o files>
378 # <composite-object>-y := <list of .o files>
380 $(filter $(addprefix $(obj)/, \
381 $($(subst $(obj)/,,$(@:.o=-objs))) \
382 $($(subst $(obj)/,,$(@:.o=-y)))), $^)
385 quiet_cmd_link_multi-y = AR $@
386 cmd_link_multi-y = rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
388 quiet_cmd_link_multi-m = AR [M] $@
389 cmd_link_multi-m = $(cmd_link_multi-y)
391 $(multi-used-y): FORCE
392 $(call if_changed,link_multi-y)
393 $(call multi_depend, $(multi-used-y), .o, -objs -y)
395 $(multi-used-m): FORCE
396 $(call if_changed,link_multi-m)
397 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
398 $(call multi_depend, $(multi-used-m), .o, -objs -y)
400 targets += $(multi-used-y) $(multi-used-m)
403 # Add intermediate targets:
404 # When building objects with specific suffix patterns, add intermediate
405 # targets that the final targets are derived from.
406 intermediate_targets = $(foreach sfx, $(2), \
407 $(patsubst %$(strip $(1)),%$(sfx), \
408 $(filter %$(strip $(1)), $(targets))))
409 # %.lex.o <- %.lex.c <- %.l
410 # %.tab.o <- %.tab.[ch] <- %.y
411 targets += $(call intermediate_targets, .lex.o, .lex.c) \
412 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
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 cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
435 ifneq ($(cmd_files),)
439 # Create directories for object files if they do not exist
440 obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
441 $(shell mkdir -p $(obj-dirs))