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1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# Building
4# ==========================================================================
5
6src := $(obj)
7
8PHONY := __build
9__build:
10
11# Init all relevant variables used in kbuild files so
12# 1) they have correct type
13# 2) they do not inherit any value from the environment
14obj-y :=
15obj-m :=
16lib-y :=
17lib-m :=
18always :=
19always-y :=
20always-m :=
21targets :=
22subdir-y :=
23subdir-m :=
24EXTRA_AFLAGS :=
25EXTRA_CFLAGS :=
26EXTRA_CPPFLAGS :=
27EXTRA_LDFLAGS :=
28asflags-y :=
29ccflags-y :=
30cppflags-y :=
31ldflags-y :=
32
33subdir-asflags-y :=
34subdir-ccflags-y :=
35
36# Read auto.conf if it exists, otherwise ignore
37-include include/config/auto.conf
38
39include scripts/Kbuild.include
40
41# The filename Kbuild has precedence over Makefile
42kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
43kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
44include $(kbuild-file)
45
46include scripts/Makefile.lib
47
48# Do not include hostprogs rules unless needed.
49# $(sort ...) is used here to remove duplicated words and excessive spaces.
50hostprogs := $(sort $(hostprogs))
51ifneq ($(hostprogs),)
52include scripts/Makefile.host
53endif
54
55# Do not include userprogs rules unless needed.
56# $(sort ...) is used here to remove duplicated words and excessive spaces.
57userprogs := $(sort $(userprogs))
58ifneq ($(userprogs),)
59include scripts/Makefile.userprogs
60endif
61
62ifndef obj
63$(warning kbuild: Makefile.build is included improperly)
64endif
65
66ifeq ($(need-modorder),)
67ifneq ($(obj-m),)
68$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
69$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
70endif
71endif
72
73# ===========================================================================
74
75# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
76subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
77subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
78
79targets-for-builtin := $(extra-y)
80
81ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
82targets-for-builtin += $(obj)/lib.a
83endif
84
85ifdef need-builtin
86targets-for-builtin += $(obj)/built-in.a
87endif
88
89targets-for-modules := $(patsubst %.o, %.mod, $(filter %.o, $(obj-m)))
90
91ifdef need-modorder
92targets-for-modules += $(obj)/modules.order
93endif
94
95targets += $(targets-for-builtin) $(targets-for-modules)
96
97# Linus' kernel sanity checking tool
98ifeq ($(KBUILD_CHECKSRC),1)
99 quiet_cmd_checksrc = CHECK $<
100 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
101else ifeq ($(KBUILD_CHECKSRC),2)
102 quiet_cmd_force_checksrc = CHECK $<
103 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
104endif
105
106ifneq ($(KBUILD_EXTRA_WARN),)
107 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $<
108endif
109
110# Compile C sources (.c)
111# ---------------------------------------------------------------------------
112
113quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
114 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
115
116$(obj)/%.s: $(src)/%.c FORCE
117 $(call if_changed_dep,cc_s_c)
118
119quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
120cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
121
122$(obj)/%.i: $(src)/%.c FORCE
123 $(call if_changed_dep,cpp_i_c)
124
125# These mirror gensymtypes_S and co below, keep them in synch.
126cmd_gensymtypes_c = \
127 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
128 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
129 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
130 $(if $(KBUILD_PRESERVE),-p) \
131 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
132
133quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
134cmd_cc_symtypes_c = \
135 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
136 test -s $@ || rm -f $@
137
138$(obj)/%.symtypes : $(src)/%.c FORCE
139 $(call cmd,cc_symtypes_c)
140
141# LLVM assembly
142# Generate .ll files from .c
143quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
144 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
145
146$(obj)/%.ll: $(src)/%.c FORCE
147 $(call if_changed_dep,cc_ll_c)
148
149# C (.c) files
150# The C file is compiled and updated dependency information is generated.
151# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
152
153quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
154 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
155
156ifdef CONFIG_MODVERSIONS
157# When module versioning is enabled the following steps are executed:
158# o compile a <file>.o from <file>.c
159# o if <file>.o doesn't contain a __ksymtab version, i.e. does
160# not export symbols, it's done.
161# o otherwise, we calculate symbol versions using the good old
162# genksyms on the preprocessed source and postprocess them in a way
163# that they are usable as a linker script
164# o generate .tmp_<file>.o from <file>.o using the linker to
165# replace the unresolved symbols __crc_exported_symbol with
166# the actual value of the checksum generated by genksyms
167# o remove .tmp_<file>.o to <file>.o
168
169cmd_modversions_c = \
170 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
171 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
172 > $(@D)/.tmp_$(@F:.o=.ver); \
173 \
174 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
175 -T $(@D)/.tmp_$(@F:.o=.ver); \
176 mv -f $(@D)/.tmp_$(@F) $@; \
177 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
178 fi
179endif
180
181ifdef CONFIG_FTRACE_MCOUNT_RECORD
182ifndef CC_USING_RECORD_MCOUNT
183# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
184ifdef BUILD_C_RECORDMCOUNT
185ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
186 RECORDMCOUNT_FLAGS = -w
187endif
188# Due to recursion, we must skip empty.o.
189# The empty.o file is created in the make process in order to determine
190# the target endianness and word size. It is made before all other C
191# files, including recordmcount.
192sub_cmd_record_mcount = \
193 if [ $(@) != "scripts/mod/empty.o" ]; then \
194 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
195 fi;
196recordmcount_source := $(srctree)/scripts/recordmcount.c \
197 $(srctree)/scripts/recordmcount.h
198else
199sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
200 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
201 "$(if $(CONFIG_64BIT),64,32)" \
202 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
203 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
204 "$(if $(part-of-module),1,0)" "$(@)";
205recordmcount_source := $(srctree)/scripts/recordmcount.pl
206endif # BUILD_C_RECORDMCOUNT
207cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
208 $(sub_cmd_record_mcount))
209endif # CC_USING_RECORD_MCOUNT
210endif # CONFIG_FTRACE_MCOUNT_RECORD
211
212ifdef CONFIG_STACK_VALIDATION
213ifneq ($(SKIP_STACK_VALIDATION),1)
214
215__objtool_obj := $(objtree)/tools/objtool/objtool
216
217objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
218
219objtool_args += $(if $(part-of-module), --module,)
220
221ifndef CONFIG_FRAME_POINTER
222objtool_args += --no-fp
223endif
224ifdef CONFIG_GCOV_KERNEL
225objtool_args += --no-unreachable
226endif
227ifdef CONFIG_RETPOLINE
228 objtool_args += --retpoline
229endif
230ifdef CONFIG_X86_SMAP
231 objtool_args += --uaccess
232endif
233
234# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
235# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
236# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
237cmd_objtool = $(if $(patsubst y%,, \
238 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
239 $(__objtool_obj) $(objtool_args) $@)
240objtool_obj = $(if $(patsubst y%,, \
241 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
242 $(__objtool_obj))
243
244endif # SKIP_STACK_VALIDATION
245endif # CONFIG_STACK_VALIDATION
246
247# Rebuild all objects when objtool changes, or is enabled/disabled.
248objtool_dep = $(objtool_obj) \
249 $(wildcard include/config/orc/unwinder.h \
250 include/config/stack/validation.h)
251
252ifdef CONFIG_TRIM_UNUSED_KSYMS
253cmd_gen_ksymdeps = \
254 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
255endif
256
257define rule_cc_o_c
258 $(call cmd_and_fixdep,cc_o_c)
259 $(call cmd,gen_ksymdeps)
260 $(call cmd,checksrc)
261 $(call cmd,checkdoc)
262 $(call cmd,objtool)
263 $(call cmd,modversions_c)
264 $(call cmd,record_mcount)
265endef
266
267define rule_as_o_S
268 $(call cmd_and_fixdep,as_o_S)
269 $(call cmd,gen_ksymdeps)
270 $(call cmd,objtool)
271 $(call cmd,modversions_S)
272endef
273
274# List module undefined symbols (or empty line if not enabled)
275ifdef CONFIG_TRIM_UNUSED_KSYMS
276cmd_undef_syms = $(NM) $< | sed -n 's/^ *U //p' | xargs echo
277else
278cmd_undef_syms = echo
279endif
280
281# Built-in and composite module parts
282$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
283 $(call if_changed_rule,cc_o_c)
284 $(call cmd,force_checksrc)
285
286cmd_mod = { \
287 echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
288 $(cmd_undef_syms); \
289 } > $@
290
291$(obj)/%.mod: $(obj)/%.o FORCE
292 $(call if_changed,mod)
293
294quiet_cmd_cc_lst_c = MKLST $@
295 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
296 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
297 System.map $(OBJDUMP) > $@
298
299$(obj)/%.lst: $(src)/%.c FORCE
300 $(call if_changed_dep,cc_lst_c)
301
302# Compile assembler sources (.S)
303# ---------------------------------------------------------------------------
304
305# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
306# or a file that it includes, in order to get versioned symbols. We build a
307# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
308# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
309#
310# This is convoluted. The .S file must first be preprocessed to run guards and
311# expand names, then the resulting exports must be constructed into plain
312# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
313# to make the genksyms input.
314#
315# These mirror gensymtypes_c and co above, keep them in synch.
316cmd_gensymtypes_S = \
317 { echo "\#include <linux/kernel.h>" ; \
318 echo "\#include <asm/asm-prototypes.h>" ; \
319 $(CPP) $(a_flags) $< | \
320 grep "\<___EXPORT_SYMBOL\>" | \
321 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
322 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
323 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
324 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
325 $(if $(KBUILD_PRESERVE),-p) \
326 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
327
328quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
329cmd_cc_symtypes_S = \
330 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
331 test -s $@ || rm -f $@
332
333$(obj)/%.symtypes : $(src)/%.S FORCE
334 $(call cmd,cc_symtypes_S)
335
336
337quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
338cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
339
340$(obj)/%.s: $(src)/%.S FORCE
341 $(call if_changed_dep,cpp_s_S)
342
343quiet_cmd_as_o_S = AS $(quiet_modtag) $@
344 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
345
346ifdef CONFIG_ASM_MODVERSIONS
347
348# versioning matches the C process described above, with difference that
349# we parse asm-prototypes.h C header to get function definitions.
350
351cmd_modversions_S = \
352 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
353 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
354 > $(@D)/.tmp_$(@F:.o=.ver); \
355 \
356 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
357 -T $(@D)/.tmp_$(@F:.o=.ver); \
358 mv -f $(@D)/.tmp_$(@F) $@; \
359 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
360 fi
361endif
362
363$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
364 $(call if_changed_rule,as_o_S)
365
366targets += $(filter-out $(subdir-builtin), $(real-obj-y))
367targets += $(filter-out $(subdir-modorder), $(real-obj-m))
368targets += $(lib-y) $(always-y) $(MAKECMDGOALS)
369
370# Linker scripts preprocessor (.lds.S -> .lds)
371# ---------------------------------------------------------------------------
372quiet_cmd_cpp_lds_S = LDS $@
373 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
374 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
375
376$(obj)/%.lds: $(src)/%.lds.S FORCE
377 $(call if_changed_dep,cpp_lds_S)
378
379# ASN.1 grammar
380# ---------------------------------------------------------------------------
381quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
382 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
383 $(basename $@).c $(basename $@).h
384
385$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
386 $(call cmd,asn1_compiler)
387
388# Build the compiled-in targets
389# ---------------------------------------------------------------------------
390
391# To build objects in subdirs, we need to descend into the directories
392$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
393$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
394
395#
396# Rule to compile a set of .o files into one .a file (without symbol table)
397#
398
399quiet_cmd_ar_builtin = AR $@
400 cmd_ar_builtin = rm -f $@; $(AR) cDPrST $@ $(real-prereqs)
401
402$(obj)/built-in.a: $(real-obj-y) FORCE
403 $(call if_changed,ar_builtin)
404
405#
406# Rule to create modules.order file
407#
408# Create commands to either record .ko file or cat modules.order from
409# a subdirectory
410# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
411# modules.order unless contained modules are updated.
412
413cmd_modules_order = { $(foreach m, $(real-prereqs), \
414 $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
415 | $(AWK) '!x[$$0]++' - > $@
416
417$(obj)/modules.order: $(obj-m) FORCE
418 $(call if_changed,modules_order)
419
420#
421# Rule to compile a set of .o files into one .a file (with symbol table)
422#
423$(obj)/lib.a: $(lib-y) FORCE
424 $(call if_changed,ar)
425
426# NOTE:
427# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
428# module is turned into a multi object module, $^ will contain header file
429# dependencies recorded in the .*.cmd file.
430quiet_cmd_link_multi-m = LD [M] $@
431 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
432
433$(multi-used-m): FORCE
434 $(call if_changed,link_multi-m)
435$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
436
437targets += $(multi-used-m)
438targets := $(filter-out $(PHONY), $(targets))
439
440# Add intermediate targets:
441# When building objects with specific suffix patterns, add intermediate
442# targets that the final targets are derived from.
443intermediate_targets = $(foreach sfx, $(2), \
444 $(patsubst %$(strip $(1)),%$(sfx), \
445 $(filter %$(strip $(1)), $(targets))))
446# %.asn1.o <- %.asn1.[ch] <- %.asn1
447# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
448# %.lex.o <- %.lex.c <- %.l
449# %.tab.o <- %.tab.[ch] <- %.y
450targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
451 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
452 $(call intermediate_targets, .lex.o, .lex.c) \
453 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
454
455# Build
456# ---------------------------------------------------------------------------
457
458ifdef single-build
459
460KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
461
462curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
463 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
464
465# Handle single targets without any rule: show "Nothing to be done for ..." or
466# "No rule to make target ..." depending on whether the target exists.
467unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
468 $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
469
470single-subdirs := $(foreach d, $(subdir-ym), \
471 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
472
473__build: $(curdir-single) $(single-subdirs)
474ifneq ($(unknown-single),)
475 $(Q)$(MAKE) -f /dev/null $(unknown-single)
476endif
477 @:
478
479ifeq ($(curdir-single),)
480# Nothing to do in this directory. Do not include any .*.cmd file for speed-up
481targets :=
482else
483targets += $(curdir-single)
484endif
485
486else
487
488__build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
489 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
490 $(subdir-ym) $(always-y)
491 @:
492
493endif
494
495# Descending
496# ---------------------------------------------------------------------------
497
498PHONY += $(subdir-ym)
499$(subdir-ym):
500 $(Q)$(MAKE) $(build)=$@ \
501 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
502 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
503 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
504
505# Add FORCE to the prequisites of a target to force it to be always rebuilt.
506# ---------------------------------------------------------------------------
507
508PHONY += FORCE
509
510FORCE:
511
512# Read all saved command lines and dependencies for the $(targets) we
513# may be building above, using $(if_changed{,_dep}). As an
514# optimization, we don't need to read them if the target does not
515# exist, we will rebuild anyway in that case.
516
517existing-targets := $(wildcard $(sort $(targets)))
518
519-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
520
521# Create directories for object files if they do not exist
522obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
523# If targets exist, their directories apparently exist. Skip mkdir.
524existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
525obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
526ifneq ($(obj-dirs),)
527$(shell mkdir -p $(obj-dirs))
528endif
529
530.PHONY: $(PHONY)
1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# Building
4# ==========================================================================
5
6src := $(obj)
7
8PHONY := $(obj)/
9$(obj)/:
10
11# Init all relevant variables used in kbuild files so
12# 1) they have correct type
13# 2) they do not inherit any value from the environment
14obj-y :=
15obj-m :=
16lib-y :=
17lib-m :=
18always-y :=
19always-m :=
20targets :=
21subdir-y :=
22subdir-m :=
23EXTRA_AFLAGS :=
24EXTRA_CFLAGS :=
25EXTRA_CPPFLAGS :=
26EXTRA_LDFLAGS :=
27asflags-y :=
28ccflags-y :=
29rustflags-y :=
30cppflags-y :=
31ldflags-y :=
32
33subdir-asflags-y :=
34subdir-ccflags-y :=
35
36# Read auto.conf if it exists, otherwise ignore
37-include include/config/auto.conf
38
39include $(srctree)/scripts/Kbuild.include
40include $(srctree)/scripts/Makefile.compiler
41include $(kbuild-file)
42include $(srctree)/scripts/Makefile.lib
43
44# Do not include hostprogs rules unless needed.
45# $(sort ...) is used here to remove duplicated words and excessive spaces.
46hostprogs := $(sort $(hostprogs))
47ifneq ($(hostprogs),)
48include $(srctree)/scripts/Makefile.host
49endif
50
51# Do not include userprogs rules unless needed.
52# $(sort ...) is used here to remove duplicated words and excessive spaces.
53userprogs := $(sort $(userprogs))
54ifneq ($(userprogs),)
55include $(srctree)/scripts/Makefile.userprogs
56endif
57
58ifndef obj
59$(warning kbuild: Makefile.build is included improperly)
60endif
61
62ifeq ($(need-modorder),)
63ifneq ($(obj-m),)
64$(warning $(patsubst %.o,'%.ko',$(obj-m)) will not be built even though obj-m is specified.)
65$(warning You cannot use subdir-y/m to visit a module Makefile. Use obj-y/m instead.)
66endif
67endif
68
69# ===========================================================================
70
71# subdir-builtin and subdir-modorder may contain duplications. Use $(sort ...)
72subdir-builtin := $(sort $(filter %/built-in.a, $(real-obj-y)))
73subdir-modorder := $(sort $(filter %/modules.order, $(obj-m)))
74subdir-dtbslist := $(sort $(filter %/dtbs-list, $(dtb-y)))
75
76targets-for-builtin := $(extra-y)
77
78ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
79targets-for-builtin += $(obj)/lib.a
80endif
81
82ifdef need-builtin
83targets-for-builtin += $(obj)/built-in.a
84endif
85
86targets-for-modules := $(foreach x, o mod, \
87 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
88
89ifdef need-modorder
90targets-for-modules += $(obj)/modules.order
91endif
92
93targets += $(targets-for-builtin) $(targets-for-modules)
94
95# Linus' kernel sanity checking tool
96ifeq ($(KBUILD_CHECKSRC),1)
97 quiet_cmd_checksrc = CHECK $<
98 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
99else ifeq ($(KBUILD_CHECKSRC),2)
100 quiet_cmd_force_checksrc = CHECK $<
101 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
102endif
103
104ifneq ($(KBUILD_EXTRA_WARN),)
105 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $(KDOCFLAGS) \
106 $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \
107 $<
108endif
109
110# Compile C sources (.c)
111# ---------------------------------------------------------------------------
112
113quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
114 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
115
116$(obj)/%.s: $(src)/%.c FORCE
117 $(call if_changed_dep,cc_s_c)
118
119quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
120cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
121
122$(obj)/%.i: $(src)/%.c FORCE
123 $(call if_changed_dep,cpp_i_c)
124
125genksyms = scripts/genksyms/genksyms \
126 $(if $(1), -T $(2)) \
127 $(if $(KBUILD_PRESERVE), -p) \
128 -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
129
130# These mirror gensymtypes_S and co below, keep them in synch.
131cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
132
133quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
134 cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
135
136$(obj)/%.symtypes : $(src)/%.c FORCE
137 $(call cmd,cc_symtypes_c)
138
139# LLVM assembly
140# Generate .ll files from .c
141quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
142 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
143
144$(obj)/%.ll: $(src)/%.c FORCE
145 $(call if_changed_dep,cc_ll_c)
146
147# C (.c) files
148# The C file is compiled and updated dependency information is generated.
149# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
150
151is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
152
153# When a module consists of a single object, there is no reason to keep LLVM IR.
154# Make $(LD) covert LLVM IR to ELF here.
155ifdef CONFIG_LTO_CLANG
156cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
157endif
158
159quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
160 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
161 $(cmd_ld_single_m) \
162 $(cmd_objtool)
163
164ifdef CONFIG_MODVERSIONS
165# When module versioning is enabled the following steps are executed:
166# o compile a <file>.o from <file>.c
167# o if <file>.o doesn't contain a __export_symbol_*, i.e. does
168# not export symbols, it's done.
169# o otherwise, we calculate symbol versions using the good old
170# genksyms on the preprocessed source and dump them into the .cmd file.
171# o modpost will extract versions from that file and create *.c files that will
172# be compiled and linked to the kernel and/or modules.
173
174gen_symversions = \
175 if $(NM) $@ 2>/dev/null | grep -q ' __export_symbol_'; then \
176 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
177 >> $(dot-target).cmd; \
178 fi
179
180cmd_gen_symversions_c = $(call gen_symversions,c)
181
182endif
183
184ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
185# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
186ifdef BUILD_C_RECORDMCOUNT
187ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
188 RECORDMCOUNT_FLAGS = -w
189endif
190# Due to recursion, we must skip empty.o.
191# The empty.o file is created in the make process in order to determine
192# the target endianness and word size. It is made before all other C
193# files, including recordmcount.
194sub_cmd_record_mcount = \
195 if [ $(@) != "scripts/mod/empty.o" ]; then \
196 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
197 fi;
198recordmcount_source := $(srctree)/scripts/recordmcount.c \
199 $(srctree)/scripts/recordmcount.h
200else
201sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
202 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
203 "$(if $(CONFIG_64BIT),64,32)" \
204 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
205 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
206 "$(if $(part-of-module),1,0)" "$(@)";
207recordmcount_source := $(srctree)/scripts/recordmcount.pl
208endif # BUILD_C_RECORDMCOUNT
209cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
210 $(sub_cmd_record_mcount))
211endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
212
213# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
214# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
215# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
216
217is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(target-stem).o)$(OBJECT_FILES_NON_STANDARD)n),y)
218
219$(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
220
221ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
222cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
223endif
224
225define rule_cc_o_c
226 $(call cmd_and_fixdep,cc_o_c)
227 $(call cmd,checksrc)
228 $(call cmd,checkdoc)
229 $(call cmd,gen_objtooldep)
230 $(call cmd,gen_symversions_c)
231 $(call cmd,record_mcount)
232 $(call cmd,warn_shared_object)
233endef
234
235define rule_as_o_S
236 $(call cmd_and_fixdep,as_o_S)
237 $(call cmd,gen_objtooldep)
238 $(call cmd,gen_symversions_S)
239 $(call cmd,warn_shared_object)
240endef
241
242# Built-in and composite module parts
243$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
244 $(call if_changed_rule,cc_o_c)
245 $(call cmd,force_checksrc)
246
247# To make this rule robust against "Argument list too long" error,
248# ensure to add $(obj)/ prefix by a shell command.
249cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
250 $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
251
252$(obj)/%.mod: FORCE
253 $(call if_changed,mod)
254
255quiet_cmd_cc_lst_c = MKLST $@
256 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
257 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
258 System.map $(OBJDUMP) > $@
259
260$(obj)/%.lst: $(src)/%.c FORCE
261 $(call if_changed_dep,cc_lst_c)
262
263# Compile Rust sources (.rs)
264# ---------------------------------------------------------------------------
265
266rust_allowed_features := new_uninit,offset_of
267
268# `--out-dir` is required to avoid temporaries being created by `rustc` in the
269# current working directory, which may be not accessible in the out-of-tree
270# modules case.
271rust_common_cmd = \
272 RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
273 -Zallow-features=$(rust_allowed_features) \
274 -Zcrate-attr=no_std \
275 -Zcrate-attr='feature($(rust_allowed_features))' \
276 -Zunstable-options --extern force:alloc --extern kernel \
277 --crate-type rlib -L $(objtree)/rust/ \
278 --crate-name $(basename $(notdir $@)) \
279 --sysroot=/dev/null \
280 --out-dir $(dir $@) --emit=dep-info=$(depfile)
281
282# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
283# will be used. We explicitly request `-Ccodegen-units=1` in any case, and
284# the compiler shows a warning if it is not 1. However, if we ever stop
285# requesting it explicitly and we start using some other `--emit` that does not
286# imply it (and for which codegen is performed), then we would be out of sync,
287# i.e. the outputs we would get for the different single targets (e.g. `.ll`)
288# would not match each other.
289
290quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
291 cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $<
292
293$(obj)/%.o: $(src)/%.rs FORCE
294 +$(call if_changed_dep,rustc_o_rs)
295
296quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
297 cmd_rustc_rsi_rs = \
298 $(rust_common_cmd) -Zunpretty=expanded $< >$@; \
299 command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@
300
301$(obj)/%.rsi: $(src)/%.rs FORCE
302 +$(call if_changed_dep,rustc_rsi_rs)
303
304quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
305 cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
306
307$(obj)/%.s: $(src)/%.rs FORCE
308 +$(call if_changed_dep,rustc_s_rs)
309
310quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
311 cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
312
313$(obj)/%.ll: $(src)/%.rs FORCE
314 +$(call if_changed_dep,rustc_ll_rs)
315
316# Compile assembler sources (.S)
317# ---------------------------------------------------------------------------
318
319# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
320# or a file that it includes, in order to get versioned symbols. We build a
321# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
322# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
323#
324# This is convoluted. The .S file must first be preprocessed to run guards and
325# expand names, then the resulting exports must be constructed into plain
326# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
327# to make the genksyms input.
328#
329# These mirror gensymtypes_c and co above, keep them in synch.
330cmd_gensymtypes_S = \
331 { echo "\#include <linux/kernel.h>" ; \
332 echo "\#include <asm/asm-prototypes.h>" ; \
333 $(NM) $@ | sed -n 's/.* __export_symbol_\(.*\)/EXPORT_SYMBOL(\1);/p' ; } | \
334 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
335
336quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
337 cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
338
339$(obj)/%.symtypes : $(src)/%.S FORCE
340 $(call cmd,cc_symtypes_S)
341
342
343quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
344cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
345
346$(obj)/%.s: $(src)/%.S FORCE
347 $(call if_changed_dep,cpp_s_S)
348
349quiet_cmd_as_o_S = AS $(quiet_modtag) $@
350 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
351
352ifdef CONFIG_ASM_MODVERSIONS
353
354# versioning matches the C process described above, with difference that
355# we parse asm-prototypes.h C header to get function definitions.
356
357cmd_gen_symversions_S = $(call gen_symversions,S)
358
359endif
360
361$(obj)/%.o: $(src)/%.S FORCE
362 $(call if_changed_rule,as_o_S)
363
364targets += $(filter-out $(subdir-builtin), $(real-obj-y))
365targets += $(filter-out $(subdir-modorder), $(real-obj-m))
366targets += $(real-dtb-y) $(lib-y) $(always-y)
367
368# Linker scripts preprocessor (.lds.S -> .lds)
369# ---------------------------------------------------------------------------
370quiet_cmd_cpp_lds_S = LDS $@
371 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
372 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
373
374$(obj)/%.lds: $(src)/%.lds.S FORCE
375 $(call if_changed_dep,cpp_lds_S)
376
377# ASN.1 grammar
378# ---------------------------------------------------------------------------
379quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
380 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
381 $(basename $@).c $(basename $@).h
382
383$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
384 $(call cmd,asn1_compiler)
385
386# Build the compiled-in targets
387# ---------------------------------------------------------------------------
388
389# To build objects in subdirs, we need to descend into the directories
390$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
391$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
392$(subdir-dtbslist): $(obj)/%/dtbs-list: $(obj)/% ;
393
394#
395# Rule to compile a set of .o files into one .a file (without symbol table)
396#
397# To make this rule robust against "Argument list too long" error,
398# remove $(obj)/ prefix, and restore it by a shell command.
399
400quiet_cmd_ar_builtin = AR $@
401 cmd_ar_builtin = rm -f $@; \
402 $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
403 $(AR) cDPrST $@
404
405$(obj)/built-in.a: $(real-obj-y) FORCE
406 $(call if_changed,ar_builtin)
407
408#
409# Rule to create modules.order and dtbs-list
410#
411# This is a list of build artifacts (module or dtb) from the current Makefile
412# and its sub-directories. The timestamp should be updated when any of the
413# member files.
414
415cmd_gen_order = { $(foreach m, $(real-prereqs), \
416 $(if $(filter %/$(notdir $@), $m), cat $m, echo $m);) :; } \
417 > $@
418
419$(obj)/modules.order: $(obj-m) FORCE
420 $(call if_changed,gen_order)
421
422$(obj)/dtbs-list: $(dtb-y) FORCE
423 $(call if_changed,gen_order)
424
425#
426# Rule to compile a set of .o files into one .a file (with symbol table)
427#
428
429$(obj)/lib.a: $(lib-y) FORCE
430 $(call if_changed,ar)
431
432quiet_cmd_ld_multi_m = LD [M] $@
433 cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
434
435define rule_ld_multi_m
436 $(call cmd_and_savecmd,ld_multi_m)
437 $(call cmd,gen_objtooldep)
438endef
439
440$(multi-obj-m): objtool-enabled := $(delay-objtool)
441$(multi-obj-m): part-of-module := y
442$(multi-obj-m): %.o: %.mod FORCE
443 $(call if_changed_rule,ld_multi_m)
444$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
445
446# Add intermediate targets:
447# When building objects with specific suffix patterns, add intermediate
448# targets that the final targets are derived from.
449intermediate_targets = $(foreach sfx, $(2), \
450 $(patsubst %$(strip $(1)),%$(sfx), \
451 $(filter %$(strip $(1)), $(targets))))
452# %.asn1.o <- %.asn1.[ch] <- %.asn1
453# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
454# %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
455# %.lex.o <- %.lex.c <- %.l
456# %.tab.o <- %.tab.[ch] <- %.y
457targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
458 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
459 $(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo) \
460 $(call intermediate_targets, .lex.o, .lex.c) \
461 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
462
463# Build
464# ---------------------------------------------------------------------------
465
466$(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
467 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
468 $(subdir-ym) $(always-y)
469 @:
470
471# Single targets
472# ---------------------------------------------------------------------------
473
474single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
475single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
476
477$(single-subdir-goals): $(single-subdirs)
478 @:
479
480# Descending
481# ---------------------------------------------------------------------------
482
483PHONY += $(subdir-ym)
484$(subdir-ym):
485 $(Q)$(MAKE) $(build)=$@ \
486 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
487 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
488 $(filter $@/%, $(single-subdir-goals))
489
490# Add FORCE to the prequisites of a target to force it to be always rebuilt.
491# ---------------------------------------------------------------------------
492
493PHONY += FORCE
494
495FORCE:
496
497targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
498targets := $(filter-out $(PHONY), $(targets))
499
500# Read all saved command lines and dependencies for the $(targets) we
501# may be building above, using $(if_changed{,_dep}). As an
502# optimization, we don't need to read them if the target does not
503# exist, we will rebuild anyway in that case.
504
505existing-targets := $(wildcard $(sort $(targets)))
506
507-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
508
509# Create directories for object files if they do not exist
510obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
511# If targets exist, their directories apparently exist. Skip mkdir.
512existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
513obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
514ifneq ($(obj-dirs),)
515$(shell mkdir -p $(obj-dirs))
516endif
517
518.PHONY: $(PHONY)