1 # SPDX-License-Identifier: GPL-2.0
2 # ==========================================================================
4 # ==========================================================================
8 src := $(patsubst $(prefix)/%,%,$(obj))
11 src := $(patsubst $(prefix)/%,%,$(obj))
14 src := $(patsubst $(prefix)/%,%,$(obj))
24 # Init all relevant variables used in kbuild files so
25 # 1) they have correct type
26 # 2) they do not inherit any value from the environment
47 # Read auto.conf if it exists, otherwise ignore
49 -include include/config/auto.conf
50 -include $(prefix)/include/autoconf.mk
52 include scripts/Kbuild.include
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 += $(PLATFORM_CPPFLAGS)
64 include scripts/Makefile.lib
66 # Do not include host rules unless needed
67 ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
68 include scripts/Makefile.host
72 $(warning kbuild: Makefile.build is included improperly)
75 # ===========================================================================
77 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
78 lib-target := $(obj)/lib.a
81 ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
82 builtin-target := $(obj)/built-in.o
85 modorder-target := $(obj)/modules.order
87 # We keep a list of all modules in $(MODVERDIR)
89 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
90 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
91 $(subdir-ym) $(always)
94 # Linus' kernel sanity checking tool
95 ifeq ($(KBUILD_CHECKSRC),1)
96 quiet_cmd_checksrc = CHECK $<
97 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
98 else ifeq ($(KBUILD_CHECKSRC),2)
99 quiet_cmd_force_checksrc = CHECK $<
100 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
103 # Do section mismatch analysis for each module/built-in.o
104 ifdef CONFIG_DEBUG_SECTION_MISMATCH
105 cmd_secanalysis = ; scripts/mod/modpost $@
108 # Compile C sources (.c)
109 # ---------------------------------------------------------------------------
111 # Default is built-in, unless we know otherwise
113 $(if $(part-of-module), \
114 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
115 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
116 quiet_modtag := $(empty) $(empty)
118 $(real-objs-m) : part-of-module := y
119 $(real-objs-m:.o=.i) : part-of-module := y
120 $(real-objs-m:.o=.s) : part-of-module := y
121 $(real-objs-m:.o=.lst): part-of-module := y
123 $(real-objs-m) : quiet_modtag := [M]
124 $(real-objs-m:.o=.i) : quiet_modtag := [M]
125 $(real-objs-m:.o=.s) : quiet_modtag := [M]
126 $(real-objs-m:.o=.lst): quiet_modtag := [M]
128 $(obj-m) : quiet_modtag := [M]
130 # Default for not multi-part modules
131 modname = $(basetarget)
133 $(multi-objs-m) : modname = $(modname-multi)
134 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
135 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
136 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
137 $(multi-objs-y) : modname = $(modname-multi)
138 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
139 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
140 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
142 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
143 cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
145 $(obj)/%.s: $(src)/%.c FORCE
146 $(call if_changed_dep,cc_s_c)
148 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
149 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
151 $(obj)/%.i: $(src)/%.c FORCE
152 $(call if_changed_dep,cc_i_c)
155 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
156 $(GENKSYMS) $(if $(1), -T $(2)) \
157 $(if $(KBUILD_PRESERVE),-p) \
158 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
160 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
161 cmd_cc_symtypes_c = \
163 $(call cmd_gensymtypes,true,$@) >/dev/null; \
164 test -s $@ || rm -f $@
166 $(obj)/%.symtypes : $(src)/%.c FORCE
167 $(call cmd,cc_symtypes_c)
170 # The C file is compiled and updated dependency information is generated.
171 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
173 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
175 ifndef CONFIG_MODVERSIONS
176 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
179 # When module versioning is enabled the following steps are executed:
180 # o compile a .tmp_<file>.o from <file>.c
181 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
182 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
184 # o otherwise, we calculate symbol versions using the good old
185 # genksyms on the preprocessed source and postprocess them in a way
186 # that they are usable as a linker script
187 # o generate <file>.o from .tmp_<file>.o using the linker to
188 # replace the unresolved symbols __crc_exported_symbol with
189 # the actual value of the checksum generated by genksyms
191 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
193 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
194 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
195 > $(@D)/.tmp_$(@F:.o=.ver); \
197 $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
198 -T $(@D)/.tmp_$(@F:.o=.ver); \
199 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
201 mv -f $(@D)/.tmp_$(@F) $@; \
205 ifdef CONFIG_FTRACE_MCOUNT_RECORD
206 # gcc 5 supports generating the mcount tables directly
207 ifneq ($(call cc-option,-mrecord-mcount,y),y)
208 KBUILD_CFLAGS += -mrecord-mcount
210 # else do it all manually
211 ifdef BUILD_C_RECORDMCOUNT
212 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
213 RECORDMCOUNT_FLAGS = -w
215 # Due to recursion, we must skip empty.o.
216 # The empty.o file is created in the make process in order to determine
217 # the target endianness and word size. It is made before all other C
218 # files, including recordmcount.
219 sub_cmd_record_mcount = \
220 if [ $(@) != "scripts/mod/empty.o" ]; then \
221 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
223 recordmcount_source := $(srctree)/scripts/recordmcount.c \
224 $(srctree)/scripts/recordmcount.h
226 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
227 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
228 "$(if $(CONFIG_64BIT),64,32)" \
229 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
230 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
231 "$(if $(part-of-module),1,0)" "$(@)";
232 recordmcount_source := $(srctree)/scripts/recordmcount.pl
234 cmd_record_mcount = \
235 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
236 "$(CC_FLAGS_FTRACE)" ]; then \
237 $(sub_cmd_record_mcount) \
239 endif # -record-mcount
243 $(call echo-cmd,checksrc) $(cmd_checksrc) \
244 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
246 $(call echo-cmd,record_mcount) \
247 $(cmd_record_mcount) \
248 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
251 mv -f $(dot-target).tmp $(dot-target).cmd
254 # Built-in and composite module parts
255 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
256 $(call cmd,force_checksrc)
257 $(call if_changed_rule,cc_o_c)
259 # Single-part modules are special since we need to mark them in $(MODVERDIR)
261 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
262 $(call cmd,force_checksrc)
263 $(call if_changed_rule,cc_o_c)
264 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
266 quiet_cmd_cc_lst_c = MKLST $@
267 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
268 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
269 System.map $(OBJDUMP) > $@
271 $(obj)/%.lst: $(src)/%.c FORCE
272 $(call if_changed_dep,cc_lst_c)
274 # Compile assembler sources (.S)
275 # ---------------------------------------------------------------------------
277 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
279 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
280 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
282 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
283 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
285 $(obj)/%.s: $(src)/%.S FORCE
286 $(call if_changed_dep,as_s_S)
288 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
289 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
291 $(obj)/%.o: $(src)/%.S FORCE
292 $(call if_changed_dep,as_o_S)
294 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
295 targets += $(extra-y) $(MAKECMDGOALS) $(always)
297 # Linker scripts preprocessor (.lds.S -> .lds)
298 # ---------------------------------------------------------------------------
299 quiet_cmd_cpp_lds_S = LDS $@
300 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
301 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
303 $(obj)/%.lds: $(src)/%.lds.S FORCE
304 $(call if_changed_dep,cpp_lds_S)
307 # ---------------------------------------------------------------------------
308 quiet_cmd_asn1_compiler = ASN.1 $@
309 cmd_asn1_compiler = $(objtree)/tools/asn1_compiler $< \
310 $(subst .h,.c,$@) $(subst .c,.h,$@)
312 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/tools/asn1_compiler
313 $(call cmd,asn1_compiler)
315 # Build the compiled-in targets
316 # ---------------------------------------------------------------------------
318 # To build objects in subdirs, we need to descend into the directories
319 $(sort $(subdir-obj-y)): $(subdir-ym) ;
322 # Rule to compile a set of .o files into one .o file
325 quiet_cmd_link_o_target = AR $@
326 # If the list of objects to link is empty, just create an empty built-in.o
327 cmd_link_o_target = $(if $(strip $(obj-y)),\
328 rm -f $@; $(AR) cDPrsT $@ $(filter $(obj-y), $^), \
329 rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@)
331 $(builtin-target): $(obj-y) FORCE
332 $(call if_changed,link_o_target)
334 targets += $(builtin-target)
335 endif # builtin-target
338 # Rule to create modules.order file
340 # Create commands to either record .ko file or cat modules.order from
343 $(foreach m, $(modorder), \
344 $(if $(filter %/modules.order, $m), \
345 cat $m;, echo kernel/$m;))
347 $(modorder-target): $(subdir-ym) FORCE
348 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
351 # Rule to compile a set of .o files into one .a file
354 quiet_cmd_link_l_target = AR $@
355 cmd_link_l_target = rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@ $(lib-y)
357 $(lib-target): $(lib-y) FORCE
358 $(call if_changed,link_l_target)
360 targets += $(lib-target)
363 quiet_cmd_link_multi-y = AR $@
364 cmd_link_multi-y = rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@ $(filter %.o,$^)
366 quiet_cmd_link_multi-m = AR [M] $@
367 cmd_link_multi-m = $(cmd_link_multi-y)
369 $(multi-used-y): FORCE
370 $(call if_changed,link_multi-y)
371 $(call multi_depend, $(multi-used-y), .o, -objs -y)
373 $(multi-used-m): FORCE
374 $(call if_changed,link_multi-m)
375 @{ echo $(@:.o=.ko); echo $(filter %.o,$^); } > $(MODVERDIR)/$(@F:.o=.mod)
376 $(call multi_depend, $(multi-used-m), .o, -objs -y)
378 targets += $(multi-used-y) $(multi-used-m)
381 # Add intermediate targets:
382 # When building objects with specific suffix patterns, add intermediate
383 # targets that the final targets are derived from.
384 intermediate_targets = $(foreach sfx, $(2), \
385 $(patsubst %$(strip $(1)),%$(sfx), \
386 $(filter %$(strip $(1)), $(targets))))
387 # %.lex.o <- %.lex.c <- %.l
388 # %.tab.o <- %.tab.[ch] <- %.y
389 targets += $(call intermediate_targets, .lex.o, .lex.c) \
390 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
393 # ---------------------------------------------------------------------------
395 PHONY += $(subdir-ym)
397 $(Q)$(MAKE) $(build)=$@
399 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
400 # ---------------------------------------------------------------------------
406 # Read all saved command lines and dependencies for the $(targets) we
407 # may be building above, using $(if_changed{,_dep}). As an
408 # optimization, we don't need to read them if the target does not
409 # exist, we will rebuild anyway in that case.
411 cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
413 ifneq ($(cmd_files),)
417 # Create directories for object files if they do not exist
418 obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
419 $(shell mkdir -p $(obj-dirs))