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 # The filename Kbuild has precedence over Makefile
52 kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
53 kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
54 include $(kbuild-file)
57 asflags-y += $(PLATFORM_CPPFLAGS)
58 ccflags-y += $(PLATFORM_CPPFLAGS)
59 cppflags-y += $(PLATFORM_CPPFLAGS)
61 include scripts/Makefile.lib
63 # Do not include host rules unless needed
64 ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
65 include scripts/Makefile.host
69 $(warning kbuild: Makefile.build is included improperly)
72 # ===========================================================================
74 ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
75 lib-target := $(obj)/lib.a
78 ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
79 builtin-target := $(obj)/built-in.o
82 modorder-target := $(obj)/modules.order
84 # We keep a list of all modules in $(MODVERDIR)
86 __build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
87 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
88 $(subdir-ym) $(always)
91 # Linus' kernel sanity checking tool
92 ifeq ($(KBUILD_CHECKSRC),1)
93 quiet_cmd_checksrc = CHECK $<
94 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
95 else ifeq ($(KBUILD_CHECKSRC),2)
96 quiet_cmd_force_checksrc = CHECK $<
97 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
100 # Do section mismatch analysis for each module/built-in.o
101 ifdef CONFIG_DEBUG_SECTION_MISMATCH
102 cmd_secanalysis = ; scripts/mod/modpost $@
105 # Compile C sources (.c)
106 # ---------------------------------------------------------------------------
108 # Default is built-in, unless we know otherwise
110 $(if $(part-of-module), \
111 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
112 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
113 quiet_modtag := $(empty) $(empty)
115 $(real-objs-m) : part-of-module := y
116 $(real-objs-m:.o=.i) : part-of-module := y
117 $(real-objs-m:.o=.s) : part-of-module := y
118 $(real-objs-m:.o=.lst): part-of-module := y
120 $(real-objs-m) : quiet_modtag := [M]
121 $(real-objs-m:.o=.i) : quiet_modtag := [M]
122 $(real-objs-m:.o=.s) : quiet_modtag := [M]
123 $(real-objs-m:.o=.lst): quiet_modtag := [M]
125 $(obj-m) : quiet_modtag := [M]
127 # Default for not multi-part modules
128 modname = $(basetarget)
130 $(multi-objs-m) : modname = $(modname-multi)
131 $(multi-objs-m:.o=.i) : modname = $(modname-multi)
132 $(multi-objs-m:.o=.s) : modname = $(modname-multi)
133 $(multi-objs-m:.o=.lst) : modname = $(modname-multi)
134 $(multi-objs-y) : modname = $(modname-multi)
135 $(multi-objs-y:.o=.i) : modname = $(modname-multi)
136 $(multi-objs-y:.o=.s) : modname = $(modname-multi)
137 $(multi-objs-y:.o=.lst) : modname = $(modname-multi)
139 quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
140 cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
142 $(obj)/%.s: $(src)/%.c FORCE
143 $(call if_changed_dep,cc_s_c)
145 quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
146 cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
148 $(obj)/%.i: $(src)/%.c FORCE
149 $(call if_changed_dep,cc_i_c)
152 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
153 $(GENKSYMS) $(if $(1), -T $(2)) \
154 $(if $(KBUILD_PRESERVE),-p) \
155 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
157 quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
158 cmd_cc_symtypes_c = \
160 $(call cmd_gensymtypes,true,$@) >/dev/null; \
161 test -s $@ || rm -f $@
163 $(obj)/%.symtypes : $(src)/%.c FORCE
164 $(call cmd,cc_symtypes_c)
167 # The C file is compiled and updated dependency information is generated.
168 # (See cmd_cc_o_c + relevant part of rule_cc_o_c)
170 quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
172 ifndef CONFIG_MODVERSIONS
173 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
176 # When module versioning is enabled the following steps are executed:
177 # o compile a .tmp_<file>.o from <file>.c
178 # o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
179 # not export symbols, we just rename .tmp_<file>.o to <file>.o and
181 # o otherwise, we calculate symbol versions using the good old
182 # genksyms on the preprocessed source and postprocess them in a way
183 # that they are usable as a linker script
184 # o generate <file>.o from .tmp_<file>.o using the linker to
185 # replace the unresolved symbols __crc_exported_symbol with
186 # the actual value of the checksum generated by genksyms
188 cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
190 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
191 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
192 > $(@D)/.tmp_$(@F:.o=.ver); \
194 $(LD) $(KBUILD_LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
195 -T $(@D)/.tmp_$(@F:.o=.ver); \
196 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
198 mv -f $(@D)/.tmp_$(@F) $@; \
202 ifdef CONFIG_FTRACE_MCOUNT_RECORD
203 # gcc 5 supports generating the mcount tables directly
204 ifneq ($(call cc-option,-mrecord-mcount,y),y)
205 KBUILD_CFLAGS += -mrecord-mcount
207 # else do it all manually
208 ifdef BUILD_C_RECORDMCOUNT
209 ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
210 RECORDMCOUNT_FLAGS = -w
212 # Due to recursion, we must skip empty.o.
213 # The empty.o file is created in the make process in order to determine
214 # the target endianness and word size. It is made before all other C
215 # files, including recordmcount.
216 sub_cmd_record_mcount = \
217 if [ $(@) != "scripts/mod/empty.o" ]; then \
218 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
220 recordmcount_source := $(srctree)/scripts/recordmcount.c \
221 $(srctree)/scripts/recordmcount.h
223 sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
224 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
225 "$(if $(CONFIG_64BIT),64,32)" \
226 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
227 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
228 "$(if $(part-of-module),1,0)" "$(@)";
229 recordmcount_source := $(srctree)/scripts/recordmcount.pl
231 cmd_record_mcount = \
232 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
233 "$(CC_FLAGS_FTRACE)" ]; then \
234 $(sub_cmd_record_mcount) \
236 endif # -record-mcount
240 $(call echo-cmd,checksrc) $(cmd_checksrc) \
241 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
243 $(call echo-cmd,record_mcount) \
244 $(cmd_record_mcount) \
245 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
248 mv -f $(dot-target).tmp $(dot-target).cmd
251 # Built-in and composite module parts
252 $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
253 $(call cmd,force_checksrc)
254 $(call if_changed_rule,cc_o_c)
256 # Single-part modules are special since we need to mark them in $(MODVERDIR)
258 $(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
259 $(call cmd,force_checksrc)
260 $(call if_changed_rule,cc_o_c)
261 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
263 quiet_cmd_cc_lst_c = MKLST $@
264 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
265 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
266 System.map $(OBJDUMP) > $@
268 $(obj)/%.lst: $(src)/%.c FORCE
269 $(call if_changed_dep,cc_lst_c)
271 # Compile assembler sources (.S)
272 # ---------------------------------------------------------------------------
274 modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
276 $(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
277 $(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
279 quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
280 cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
282 $(obj)/%.s: $(src)/%.S FORCE
283 $(call if_changed_dep,as_s_S)
285 quiet_cmd_as_o_S = AS $(quiet_modtag) $@
286 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
288 $(obj)/%.o: $(src)/%.S FORCE
289 $(call if_changed_dep,as_o_S)
291 targets += $(real-objs-y) $(real-objs-m) $(lib-y)
292 targets += $(extra-y) $(MAKECMDGOALS) $(always)
294 # Linker scripts preprocessor (.lds.S -> .lds)
295 # ---------------------------------------------------------------------------
296 quiet_cmd_cpp_lds_S = LDS $@
297 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
298 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
300 $(obj)/%.lds: $(src)/%.lds.S FORCE
301 $(call if_changed_dep,cpp_lds_S)
304 # ---------------------------------------------------------------------------
305 quiet_cmd_asn1_compiler = ASN.1 $@
306 cmd_asn1_compiler = $(objtree)/tools/asn1_compiler $< \
307 $(subst .h,.c,$@) $(subst .c,.h,$@)
309 $(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/tools/asn1_compiler
310 $(call cmd,asn1_compiler)
312 # Build the compiled-in targets
313 # ---------------------------------------------------------------------------
315 # To build objects in subdirs, we need to descend into the directories
316 $(sort $(subdir-obj-y)): $(subdir-ym) ;
319 # Rule to compile a set of .o files into one .o file
322 quiet_cmd_link_o_target = AR $@
323 # If the list of objects to link is empty, just create an empty built-in.o
324 cmd_link_o_target = $(if $(strip $(obj-y)),\
325 rm -f $@; $(AR) cDPrsT $@ $(filter $(obj-y), $^), \
326 rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@)
328 $(builtin-target): $(obj-y) FORCE
329 $(call if_changed,link_o_target)
331 targets += $(builtin-target)
332 endif # builtin-target
335 # Rule to create modules.order file
337 # Create commands to either record .ko file or cat modules.order from
340 $(foreach m, $(modorder), \
341 $(if $(filter %/modules.order, $m), \
342 cat $m;, echo kernel/$m;))
344 $(modorder-target): $(subdir-ym) FORCE
345 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
348 # Rule to compile a set of .o files into one .a file
351 quiet_cmd_link_l_target = AR $@
352 cmd_link_l_target = rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@ $(lib-y)
354 $(lib-target): $(lib-y) FORCE
355 $(call if_changed,link_l_target)
357 targets += $(lib-target)
360 quiet_cmd_link_multi-y = AR $@
361 cmd_link_multi-y = rm -f $@; $(AR) cDPrsT$(KBUILD_ARFLAGS) $@ $(filter %.o,$^)
363 quiet_cmd_link_multi-m = AR [M] $@
364 cmd_link_multi-m = $(cmd_link_multi-y)
366 $(multi-used-y): FORCE
367 $(call if_changed,link_multi-y)
368 $(call multi_depend, $(multi-used-y), .o, -objs -y)
370 $(multi-used-m): FORCE
371 $(call if_changed,link_multi-m)
372 @{ echo $(@:.o=.ko); echo $(filter %.o,$^); } > $(MODVERDIR)/$(@F:.o=.mod)
373 $(call multi_depend, $(multi-used-m), .o, -objs -y)
375 targets += $(multi-used-y) $(multi-used-m)
378 # Add intermediate targets:
379 # When building objects with specific suffix patterns, add intermediate
380 # targets that the final targets are derived from.
381 intermediate_targets = $(foreach sfx, $(2), \
382 $(patsubst %$(strip $(1)),%$(sfx), \
383 $(filter %$(strip $(1)), $(targets))))
384 # %.lex.o <- %.lex.c <- %.l
385 # %.tab.o <- %.tab.[ch] <- %.y
386 targets += $(call intermediate_targets, .lex.o, .lex.c) \
387 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
390 # ---------------------------------------------------------------------------
392 PHONY += $(subdir-ym)
394 $(Q)$(MAKE) $(build)=$@
396 # Add FORCE to the prequisites of a target to force it to be always rebuilt.
397 # ---------------------------------------------------------------------------
403 # Read all saved command lines and dependencies for the $(targets) we
404 # may be building above, using $(if_changed{,_dep}). As an
405 # optimization, we don't need to read them if the target does not
406 # exist, we will rebuild anyway in that case.
408 cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
410 ifneq ($(cmd_files),)
414 # Create directories for object files if they do not exist
415 obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
416 $(shell mkdir -p $(obj-dirs))