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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)))
74
75targets-for-builtin := $(extra-y)
76
77ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
78targets-for-builtin += $(obj)/lib.a
79endif
80
81ifdef need-builtin
82targets-for-builtin += $(obj)/built-in.a
83endif
84
85targets-for-modules := $(foreach x, o mod, \
86 $(patsubst %.o, %.$x, $(filter %.o, $(obj-m))))
87
88ifdef need-modorder
89targets-for-modules += $(obj)/modules.order
90endif
91
92targets += $(targets-for-builtin) $(targets-for-modules)
93
94# Linus' kernel sanity checking tool
95ifeq ($(KBUILD_CHECKSRC),1)
96 quiet_cmd_checksrc = CHECK $<
97 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
98else ifeq ($(KBUILD_CHECKSRC),2)
99 quiet_cmd_force_checksrc = CHECK $<
100 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $<
101endif
102
103ifneq ($(KBUILD_EXTRA_WARN),)
104 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $(KDOCFLAGS) \
105 $(if $(findstring 2, $(KBUILD_EXTRA_WARN)), -Wall) \
106 $<
107endif
108
109# Compile C sources (.c)
110# ---------------------------------------------------------------------------
111
112quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
113 cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS) $(CC_FLAGS_LTO), $(c_flags)) -fverbose-asm -S -o $@ $<
114
115$(obj)/%.s: $(src)/%.c FORCE
116 $(call if_changed_dep,cc_s_c)
117
118quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
119cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
120
121$(obj)/%.i: $(src)/%.c FORCE
122 $(call if_changed_dep,cpp_i_c)
123
124genksyms = scripts/genksyms/genksyms \
125 $(if $(1), -T $(2)) \
126 $(if $(KBUILD_PRESERVE), -p) \
127 -r $(or $(wildcard $(2:.symtypes=.symref)), /dev/null)
128
129# These mirror gensymtypes_S and co below, keep them in synch.
130cmd_gensymtypes_c = $(CPP) -D__GENKSYMS__ $(c_flags) $< | $(genksyms)
131
132quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
133 cmd_cc_symtypes_c = $(call cmd_gensymtypes_c,true,$@) >/dev/null
134
135$(obj)/%.symtypes : $(src)/%.c FORCE
136 $(call cmd,cc_symtypes_c)
137
138# LLVM assembly
139# Generate .ll files from .c
140quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
141 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -fno-discard-value-names -o $@ $<
142
143$(obj)/%.ll: $(src)/%.c FORCE
144 $(call if_changed_dep,cc_ll_c)
145
146# C (.c) files
147# The C file is compiled and updated dependency information is generated.
148# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
149
150is-single-obj-m = $(and $(part-of-module),$(filter $@, $(obj-m)),y)
151
152# When a module consists of a single object, there is no reason to keep LLVM IR.
153# Make $(LD) covert LLVM IR to ELF here.
154ifdef CONFIG_LTO_CLANG
155cmd_ld_single_m = $(if $(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
156endif
157
158quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
159 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
160 $(cmd_ld_single_m) \
161 $(cmd_objtool)
162
163ifdef CONFIG_MODVERSIONS
164# When module versioning is enabled the following steps are executed:
165# o compile a <file>.o from <file>.c
166# o if <file>.o doesn't contain a __export_symbol_*, i.e. does
167# not export symbols, it's done.
168# o otherwise, we calculate symbol versions using the good old
169# genksyms on the preprocessed source and dump them into the .cmd file.
170# o modpost will extract versions from that file and create *.c files that will
171# be compiled and linked to the kernel and/or modules.
172
173gen_symversions = \
174 if $(NM) $@ 2>/dev/null | grep -q ' __export_symbol_'; then \
175 $(call cmd_gensymtypes_$(1),$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
176 >> $(dot-target).cmd; \
177 fi
178
179cmd_gen_symversions_c = $(call gen_symversions,c)
180
181endif
182
183ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
184# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
185ifdef BUILD_C_RECORDMCOUNT
186ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
187 RECORDMCOUNT_FLAGS = -w
188endif
189# Due to recursion, we must skip empty.o.
190# The empty.o file is created in the make process in order to determine
191# the target endianness and word size. It is made before all other C
192# files, including recordmcount.
193sub_cmd_record_mcount = \
194 if [ $(@) != "scripts/mod/empty.o" ]; then \
195 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
196 fi;
197recordmcount_source := $(srctree)/scripts/recordmcount.c \
198 $(srctree)/scripts/recordmcount.h
199else
200sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
201 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
202 "$(if $(CONFIG_64BIT),64,32)" \
203 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
204 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
205 "$(if $(part-of-module),1,0)" "$(@)";
206recordmcount_source := $(srctree)/scripts/recordmcount.pl
207endif # BUILD_C_RECORDMCOUNT
208cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
209 $(sub_cmd_record_mcount))
210endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
211
212# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
213# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
214# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
215
216is-standard-object = $(if $(filter-out y%, $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n),y)
217
218$(obj)/%.o: objtool-enabled = $(if $(is-standard-object),$(if $(delay-objtool),$(is-single-obj-m),y))
219
220ifneq ($(findstring 1, $(KBUILD_EXTRA_WARN)),)
221cmd_warn_shared_object = $(if $(word 2, $(modname-multi)),$(warning $(kbuild-file): $*.o is added to multiple modules: $(modname-multi)))
222endif
223
224define rule_cc_o_c
225 $(call cmd_and_fixdep,cc_o_c)
226 $(call cmd,checksrc)
227 $(call cmd,checkdoc)
228 $(call cmd,gen_objtooldep)
229 $(call cmd,gen_symversions_c)
230 $(call cmd,record_mcount)
231 $(call cmd,warn_shared_object)
232endef
233
234define rule_as_o_S
235 $(call cmd_and_fixdep,as_o_S)
236 $(call cmd,gen_objtooldep)
237 $(call cmd,gen_symversions_S)
238 $(call cmd,warn_shared_object)
239endef
240
241# Built-in and composite module parts
242$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
243 $(call if_changed_rule,cc_o_c)
244 $(call cmd,force_checksrc)
245
246# To make this rule robust against "Argument list too long" error,
247# ensure to add $(obj)/ prefix by a shell command.
248cmd_mod = printf '%s\n' $(call real-search, $*.o, .o, -objs -y -m) | \
249 $(AWK) '!x[$$0]++ { print("$(obj)/"$$0) }' > $@
250
251$(obj)/%.mod: FORCE
252 $(call if_changed,mod)
253
254quiet_cmd_cc_lst_c = MKLST $@
255 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
256 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
257 System.map $(OBJDUMP) > $@
258
259$(obj)/%.lst: $(src)/%.c FORCE
260 $(call if_changed_dep,cc_lst_c)
261
262# Compile Rust sources (.rs)
263# ---------------------------------------------------------------------------
264
265rust_allowed_features := new_uninit,offset_of
266
267# `--out-dir` is required to avoid temporaries being created by `rustc` in the
268# current working directory, which may be not accessible in the out-of-tree
269# modules case.
270rust_common_cmd = \
271 RUST_MODFILE=$(modfile) $(RUSTC_OR_CLIPPY) $(rust_flags) \
272 -Zallow-features=$(rust_allowed_features) \
273 -Zcrate-attr=no_std \
274 -Zcrate-attr='feature($(rust_allowed_features))' \
275 --extern alloc --extern kernel \
276 --crate-type rlib -L $(objtree)/rust/ \
277 --crate-name $(basename $(notdir $@)) \
278 --sysroot=/dev/null \
279 --out-dir $(dir $@) --emit=dep-info=$(depfile)
280
281# `--emit=obj`, `--emit=asm` and `--emit=llvm-ir` imply a single codegen unit
282# will be used. We explicitly request `-Ccodegen-units=1` in any case, and
283# the compiler shows a warning if it is not 1. However, if we ever stop
284# requesting it explicitly and we start using some other `--emit` that does not
285# imply it (and for which codegen is performed), then we would be out of sync,
286# i.e. the outputs we would get for the different single targets (e.g. `.ll`)
287# would not match each other.
288
289quiet_cmd_rustc_o_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
290 cmd_rustc_o_rs = $(rust_common_cmd) --emit=obj=$@ $<
291
292$(obj)/%.o: $(src)/%.rs FORCE
293 $(call if_changed_dep,rustc_o_rs)
294
295quiet_cmd_rustc_rsi_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
296 cmd_rustc_rsi_rs = \
297 $(rust_common_cmd) -Zunpretty=expanded $< >$@; \
298 command -v $(RUSTFMT) >/dev/null && $(RUSTFMT) $@
299
300$(obj)/%.rsi: $(src)/%.rs FORCE
301 $(call if_changed_dep,rustc_rsi_rs)
302
303quiet_cmd_rustc_s_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
304 cmd_rustc_s_rs = $(rust_common_cmd) --emit=asm=$@ $<
305
306$(obj)/%.s: $(src)/%.rs FORCE
307 $(call if_changed_dep,rustc_s_rs)
308
309quiet_cmd_rustc_ll_rs = $(RUSTC_OR_CLIPPY_QUIET) $(quiet_modtag) $@
310 cmd_rustc_ll_rs = $(rust_common_cmd) --emit=llvm-ir=$@ $<
311
312$(obj)/%.ll: $(src)/%.rs FORCE
313 $(call if_changed_dep,rustc_ll_rs)
314
315# Compile assembler sources (.S)
316# ---------------------------------------------------------------------------
317
318# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
319# or a file that it includes, in order to get versioned symbols. We build a
320# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
321# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
322#
323# This is convoluted. The .S file must first be preprocessed to run guards and
324# expand names, then the resulting exports must be constructed into plain
325# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
326# to make the genksyms input.
327#
328# These mirror gensymtypes_c and co above, keep them in synch.
329cmd_gensymtypes_S = \
330 { echo "\#include <linux/kernel.h>" ; \
331 echo "\#include <asm/asm-prototypes.h>" ; \
332 $(NM) $@ | sed -n 's/.* __export_symbol_\(.*\)/EXPORT_SYMBOL(\1);/p' ; } | \
333 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | $(genksyms)
334
335quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
336 cmd_cc_symtypes_S = $(call cmd_gensymtypes_S,true,$@) >/dev/null
337
338$(obj)/%.symtypes : $(src)/%.S FORCE
339 $(call cmd,cc_symtypes_S)
340
341
342quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
343cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
344
345$(obj)/%.s: $(src)/%.S FORCE
346 $(call if_changed_dep,cpp_s_S)
347
348quiet_cmd_as_o_S = AS $(quiet_modtag) $@
349 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
350
351ifdef CONFIG_ASM_MODVERSIONS
352
353# versioning matches the C process described above, with difference that
354# we parse asm-prototypes.h C header to get function definitions.
355
356cmd_gen_symversions_S = $(call gen_symversions,S)
357
358endif
359
360$(obj)/%.o: $(src)/%.S FORCE
361 $(call if_changed_rule,as_o_S)
362
363targets += $(filter-out $(subdir-builtin), $(real-obj-y))
364targets += $(filter-out $(subdir-modorder), $(real-obj-m))
365targets += $(real-dtb-y) $(lib-y) $(always-y)
366
367# Linker scripts preprocessor (.lds.S -> .lds)
368# ---------------------------------------------------------------------------
369quiet_cmd_cpp_lds_S = LDS $@
370 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
371 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
372
373$(obj)/%.lds: $(src)/%.lds.S FORCE
374 $(call if_changed_dep,cpp_lds_S)
375
376# ASN.1 grammar
377# ---------------------------------------------------------------------------
378quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
379 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
380 $(basename $@).c $(basename $@).h
381
382$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
383 $(call cmd,asn1_compiler)
384
385# Build the compiled-in targets
386# ---------------------------------------------------------------------------
387
388# To build objects in subdirs, we need to descend into the directories
389$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
390$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
391
392#
393# Rule to compile a set of .o files into one .a file (without symbol table)
394#
395# To make this rule robust against "Argument list too long" error,
396# remove $(obj)/ prefix, and restore it by a shell command.
397
398quiet_cmd_ar_builtin = AR $@
399 cmd_ar_builtin = rm -f $@; \
400 $(if $(real-prereqs), printf "$(obj)/%s " $(patsubst $(obj)/%,%,$(real-prereqs)) | xargs) \
401 $(AR) cDPrST $@
402
403$(obj)/built-in.a: $(real-obj-y) FORCE
404 $(call if_changed,ar_builtin)
405
406#
407# Rule to create modules.order file
408#
409# Create commands to either record .ko file or cat modules.order from
410# a subdirectory
411# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
412# modules.order unless contained modules are updated.
413
414cmd_modules_order = { $(foreach m, $(real-prereqs), \
415 $(if $(filter %/modules.order, $m), cat $m, echo $m);) :; } \
416 > $@
417
418$(obj)/modules.order: $(obj-m) FORCE
419 $(call if_changed,modules_order)
420
421#
422# Rule to compile a set of .o files into one .a file (with symbol table)
423#
424
425$(obj)/lib.a: $(lib-y) FORCE
426 $(call if_changed,ar)
427
428quiet_cmd_ld_multi_m = LD [M] $@
429 cmd_ld_multi_m = $(LD) $(ld_flags) -r -o $@ @$< $(cmd_objtool)
430
431define rule_ld_multi_m
432 $(call cmd_and_savecmd,ld_multi_m)
433 $(call cmd,gen_objtooldep)
434endef
435
436$(multi-obj-m): objtool-enabled := $(delay-objtool)
437$(multi-obj-m): part-of-module := y
438$(multi-obj-m): %.o: %.mod FORCE
439 $(call if_changed_rule,ld_multi_m)
440$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
441
442# Add intermediate targets:
443# When building objects with specific suffix patterns, add intermediate
444# targets that the final targets are derived from.
445intermediate_targets = $(foreach sfx, $(2), \
446 $(patsubst %$(strip $(1)),%$(sfx), \
447 $(filter %$(strip $(1)), $(targets))))
448# %.asn1.o <- %.asn1.[ch] <- %.asn1
449# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
450# %.dtbo.o <- %.dtbo.S <- %.dtbo <- %.dtso
451# %.lex.o <- %.lex.c <- %.l
452# %.tab.o <- %.tab.[ch] <- %.y
453targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
454 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
455 $(call intermediate_targets, .dtbo.o, .dtbo.S .dtbo) \
456 $(call intermediate_targets, .lex.o, .lex.c) \
457 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
458
459# Build
460# ---------------------------------------------------------------------------
461
462$(obj)/: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
463 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
464 $(subdir-ym) $(always-y)
465 @:
466
467# Single targets
468# ---------------------------------------------------------------------------
469
470single-subdirs := $(foreach d, $(subdir-ym), $(if $(filter $d/%, $(MAKECMDGOALS)), $d))
471single-subdir-goals := $(filter $(addsuffix /%, $(single-subdirs)), $(MAKECMDGOALS))
472
473$(single-subdir-goals): $(single-subdirs)
474 @:
475
476# Descending
477# ---------------------------------------------------------------------------
478
479PHONY += $(subdir-ym)
480$(subdir-ym):
481 $(Q)$(MAKE) $(build)=$@ \
482 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
483 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1) \
484 $(filter $@/%, $(single-subdir-goals))
485
486# Add FORCE to the prequisites of a target to force it to be always rebuilt.
487# ---------------------------------------------------------------------------
488
489PHONY += FORCE
490
491FORCE:
492
493targets += $(filter-out $(single-subdir-goals), $(MAKECMDGOALS))
494targets := $(filter-out $(PHONY), $(targets))
495
496# Read all saved command lines and dependencies for the $(targets) we
497# may be building above, using $(if_changed{,_dep}). As an
498# optimization, we don't need to read them if the target does not
499# exist, we will rebuild anyway in that case.
500
501existing-targets := $(wildcard $(sort $(targets)))
502
503-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
504
505# Create directories for object files if they do not exist
506obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
507# If targets exist, their directories apparently exist. Skip mkdir.
508existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
509obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
510ifneq ($(obj-dirs),)
511$(shell mkdir -p $(obj-dirs))
512endif
513
514.PHONY: $(PHONY)
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-y :=
19always-m :=
20targets :=
21subdir-y :=
22subdir-m :=
23EXTRA_AFLAGS :=
24EXTRA_CFLAGS :=
25EXTRA_CPPFLAGS :=
26EXTRA_LDFLAGS :=
27asflags-y :=
28ccflags-y :=
29cppflags-y :=
30ldflags-y :=
31
32subdir-asflags-y :=
33subdir-ccflags-y :=
34
35# Read auto.conf if it exists, otherwise ignore
36-include include/config/auto.conf
37
38include $(srctree)/scripts/Kbuild.include
39include $(srctree)/scripts/Makefile.compiler
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 $(srctree)/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 $(srctree)/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 $(srctree)/scripts/Makefile.userprogs
60endif
61
62ifndef obj
63$(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) $(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
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
169ifdef CONFIG_LTO_CLANG
170# Generate .o.symversions files for each .o with exported symbols, and link these
171# to the kernel and/or modules at the end.
172cmd_modversions_c = \
173 if $(NM) $@ 2>/dev/null | grep -q __ksymtab; then \
174 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
175 > $@.symversions; \
176 fi;
177else
178cmd_modversions_c = \
179 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
180 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
181 > $(@D)/.tmp_$(@F:.o=.ver); \
182 \
183 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
184 -T $(@D)/.tmp_$(@F:.o=.ver); \
185 mv -f $(@D)/.tmp_$(@F) $@; \
186 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
187 fi
188endif
189endif
190
191ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
192# compiler will not generate __mcount_loc use recordmcount or recordmcount.pl
193ifdef BUILD_C_RECORDMCOUNT
194ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
195 RECORDMCOUNT_FLAGS = -w
196endif
197# Due to recursion, we must skip empty.o.
198# The empty.o file is created in the make process in order to determine
199# the target endianness and word size. It is made before all other C
200# files, including recordmcount.
201sub_cmd_record_mcount = \
202 if [ $(@) != "scripts/mod/empty.o" ]; then \
203 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
204 fi;
205recordmcount_source := $(srctree)/scripts/recordmcount.c \
206 $(srctree)/scripts/recordmcount.h
207else
208sub_cmd_record_mcount = perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
209 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
210 "$(if $(CONFIG_64BIT),64,32)" \
211 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \
212 "$(LD) $(KBUILD_LDFLAGS)" "$(NM)" "$(RM)" "$(MV)" \
213 "$(if $(part-of-module),1,0)" "$(@)";
214recordmcount_source := $(srctree)/scripts/recordmcount.pl
215endif # BUILD_C_RECORDMCOUNT
216cmd_record_mcount = $(if $(findstring $(strip $(CC_FLAGS_FTRACE)),$(_c_flags)), \
217 $(sub_cmd_record_mcount))
218endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
219
220ifdef CONFIG_STACK_VALIDATION
221ifndef CONFIG_LTO_CLANG
222
223__objtool_obj := $(objtree)/tools/objtool/objtool
224
225# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
226# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
227# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
228cmd_objtool = $(if $(patsubst y%,, \
229 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
230 $(__objtool_obj) $(objtool_args) $@)
231objtool_obj = $(if $(patsubst y%,, \
232 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
233 $(__objtool_obj))
234
235endif # CONFIG_LTO_CLANG
236endif # CONFIG_STACK_VALIDATION
237
238# Rebuild all objects when objtool changes, or is enabled/disabled.
239objtool_dep = $(objtool_obj) \
240 $(wildcard include/config/ORC_UNWINDER \
241 include/config/STACK_VALIDATION)
242
243ifdef CONFIG_TRIM_UNUSED_KSYMS
244cmd_gen_ksymdeps = \
245 $(CONFIG_SHELL) $(srctree)/scripts/gen_ksymdeps.sh $@ >> $(dot-target).cmd
246
247# List module undefined symbols
248undefined_syms = $(NM) $< | $(AWK) '$$1 == "U" { printf("%s%s", x++ ? " " : "", $$2) }';
249endif
250
251define rule_cc_o_c
252 $(call cmd_and_fixdep,cc_o_c)
253 $(call cmd,gen_ksymdeps)
254 $(call cmd,checksrc)
255 $(call cmd,checkdoc)
256 $(call cmd,objtool)
257 $(call cmd,modversions_c)
258 $(call cmd,record_mcount)
259endef
260
261define rule_as_o_S
262 $(call cmd_and_fixdep,as_o_S)
263 $(call cmd,gen_ksymdeps)
264 $(call cmd,objtool)
265 $(call cmd,modversions_S)
266endef
267
268# Built-in and composite module parts
269.SECONDEXPANSION:
270$(obj)/%.o: $(src)/%.c $(recordmcount_source) $$(objtool_dep) FORCE
271 $(call if_changed_rule,cc_o_c)
272 $(call cmd,force_checksrc)
273
274cmd_mod = { \
275 echo $(if $($*-objs)$($*-y)$($*-m), $(addprefix $(obj)/, $($*-objs) $($*-y) $($*-m)), $(@:.mod=.o)); \
276 $(undefined_syms) echo; \
277 } > $@
278
279$(obj)/%.mod: $(obj)/%.o FORCE
280 $(call if_changed,mod)
281
282quiet_cmd_cc_lst_c = MKLST $@
283 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
284 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
285 System.map $(OBJDUMP) > $@
286
287$(obj)/%.lst: $(src)/%.c FORCE
288 $(call if_changed_dep,cc_lst_c)
289
290# Compile assembler sources (.S)
291# ---------------------------------------------------------------------------
292
293# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
294# or a file that it includes, in order to get versioned symbols. We build a
295# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
296# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
297#
298# This is convoluted. The .S file must first be preprocessed to run guards and
299# expand names, then the resulting exports must be constructed into plain
300# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
301# to make the genksyms input.
302#
303# These mirror gensymtypes_c and co above, keep them in synch.
304cmd_gensymtypes_S = \
305 { echo "\#include <linux/kernel.h>" ; \
306 echo "\#include <asm/asm-prototypes.h>" ; \
307 $(CPP) $(a_flags) $< | \
308 grep "\<___EXPORT_SYMBOL\>" | \
309 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ; } | \
310 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
311 scripts/genksyms/genksyms $(if $(1), -T $(2)) \
312 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
313 $(if $(KBUILD_PRESERVE),-p) \
314 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
315
316quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
317cmd_cc_symtypes_S = \
318 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
319 test -s $@ || rm -f $@
320
321$(obj)/%.symtypes : $(src)/%.S FORCE
322 $(call cmd,cc_symtypes_S)
323
324
325quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
326cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
327
328$(obj)/%.s: $(src)/%.S FORCE
329 $(call if_changed_dep,cpp_s_S)
330
331quiet_cmd_as_o_S = AS $(quiet_modtag) $@
332 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
333
334ifdef CONFIG_ASM_MODVERSIONS
335
336# versioning matches the C process described above, with difference that
337# we parse asm-prototypes.h C header to get function definitions.
338
339cmd_modversions_S = \
340 if $(OBJDUMP) -h $@ | grep -q __ksymtab; then \
341 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
342 > $(@D)/.tmp_$(@F:.o=.ver); \
343 \
344 $(LD) $(KBUILD_LDFLAGS) -r -o $(@D)/.tmp_$(@F) $@ \
345 -T $(@D)/.tmp_$(@F:.o=.ver); \
346 mv -f $(@D)/.tmp_$(@F) $@; \
347 rm -f $(@D)/.tmp_$(@F:.o=.ver); \
348 fi
349endif
350
351$(obj)/%.o: $(src)/%.S $$(objtool_dep) FORCE
352 $(call if_changed_rule,as_o_S)
353
354targets += $(filter-out $(subdir-builtin), $(real-obj-y))
355targets += $(filter-out $(subdir-modorder), $(real-obj-m))
356targets += $(real-dtb-y) $(lib-y) $(always-y) $(MAKECMDGOALS)
357
358# Linker scripts preprocessor (.lds.S -> .lds)
359# ---------------------------------------------------------------------------
360quiet_cmd_cpp_lds_S = LDS $@
361 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
362 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
363
364$(obj)/%.lds: $(src)/%.lds.S FORCE
365 $(call if_changed_dep,cpp_lds_S)
366
367# ASN.1 grammar
368# ---------------------------------------------------------------------------
369quiet_cmd_asn1_compiler = ASN.1 $(basename $@).[ch]
370 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
371 $(basename $@).c $(basename $@).h
372
373$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
374 $(call cmd,asn1_compiler)
375
376# Build the compiled-in targets
377# ---------------------------------------------------------------------------
378
379# To build objects in subdirs, we need to descend into the directories
380$(subdir-builtin): $(obj)/%/built-in.a: $(obj)/% ;
381$(subdir-modorder): $(obj)/%/modules.order: $(obj)/% ;
382
383# combine symversions for later processing
384quiet_cmd_update_lto_symversions = SYMVER $@
385ifeq ($(CONFIG_LTO_CLANG) $(CONFIG_MODVERSIONS),y y)
386 cmd_update_lto_symversions = \
387 rm -f $@.symversions \
388 $(foreach n, $(filter-out FORCE,$^), \
389 $(if $(shell test -s $(n).symversions && echo y), \
390 ; cat $(n).symversions >> $@.symversions))
391else
392 cmd_update_lto_symversions = echo >/dev/null
393endif
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
402quiet_cmd_ar_and_symver = AR $@
403 cmd_ar_and_symver = $(cmd_update_lto_symversions); $(cmd_ar_builtin)
404
405$(obj)/built-in.a: $(real-obj-y) FORCE
406 $(call if_changed,ar_and_symver)
407
408#
409# Rule to create modules.order file
410#
411# Create commands to either record .ko file or cat modules.order from
412# a subdirectory
413# Add $(obj-m) as the prerequisite to avoid updating the timestamp of
414# modules.order unless contained modules are updated.
415
416cmd_modules_order = { $(foreach m, $(real-prereqs), \
417 $(if $(filter %/modules.order, $m), cat $m, echo $(patsubst %.o,%.ko,$m));) :; } \
418 | $(AWK) '!x[$$0]++' - > $@
419
420$(obj)/modules.order: $(obj-m) FORCE
421 $(call if_changed,modules_order)
422
423#
424# Rule to compile a set of .o files into one .a file (with symbol table)
425#
426quiet_cmd_ar_lib = AR $@
427 cmd_ar_lib = $(cmd_update_lto_symversions); $(cmd_ar)
428
429$(obj)/lib.a: $(lib-y) FORCE
430 $(call if_changed,ar_lib)
431
432# NOTE:
433# Do not replace $(filter %.o,^) with $(real-prereqs). When a single object
434# module is turned into a multi object module, $^ will contain header file
435# dependencies recorded in the .*.cmd file.
436ifdef CONFIG_LTO_CLANG
437quiet_cmd_link_multi-m = AR [M] $@
438cmd_link_multi-m = \
439 $(cmd_update_lto_symversions); \
440 rm -f $@; \
441 $(AR) cDPrsT $@ $(filter %.o,$^)
442else
443quiet_cmd_link_multi-m = LD [M] $@
444 cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(filter %.o,$^)
445endif
446
447$(multi-obj-m): FORCE
448 $(call if_changed,link_multi-m)
449$(call multi_depend, $(multi-obj-m), .o, -objs -y -m)
450
451targets += $(multi-obj-m)
452targets := $(filter-out $(PHONY), $(targets))
453
454# Add intermediate targets:
455# When building objects with specific suffix patterns, add intermediate
456# targets that the final targets are derived from.
457intermediate_targets = $(foreach sfx, $(2), \
458 $(patsubst %$(strip $(1)),%$(sfx), \
459 $(filter %$(strip $(1)), $(targets))))
460# %.asn1.o <- %.asn1.[ch] <- %.asn1
461# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
462# %.lex.o <- %.lex.c <- %.l
463# %.tab.o <- %.tab.[ch] <- %.y
464targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
465 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
466 $(call intermediate_targets, .lex.o, .lex.c) \
467 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
468
469# Build
470# ---------------------------------------------------------------------------
471
472ifdef single-build
473
474KBUILD_SINGLE_TARGETS := $(filter $(obj)/%, $(KBUILD_SINGLE_TARGETS))
475
476curdir-single := $(sort $(foreach x, $(KBUILD_SINGLE_TARGETS), \
477 $(if $(filter $(x) $(basename $(x)).o, $(targets)), $(x))))
478
479# Handle single targets without any rule: show "Nothing to be done for ..." or
480# "No rule to make target ..." depending on whether the target exists.
481unknown-single := $(filter-out $(addsuffix /%, $(subdir-ym)), \
482 $(filter-out $(curdir-single), $(KBUILD_SINGLE_TARGETS)))
483
484single-subdirs := $(foreach d, $(subdir-ym), \
485 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
486
487__build: $(curdir-single) $(single-subdirs)
488ifneq ($(unknown-single),)
489 $(Q)$(MAKE) -f /dev/null $(unknown-single)
490endif
491 @:
492
493ifeq ($(curdir-single),)
494# Nothing to do in this directory. Do not include any .*.cmd file for speed-up
495targets :=
496else
497targets += $(curdir-single)
498endif
499
500else
501
502__build: $(if $(KBUILD_BUILTIN), $(targets-for-builtin)) \
503 $(if $(KBUILD_MODULES), $(targets-for-modules)) \
504 $(subdir-ym) $(always-y)
505 @:
506
507endif
508
509# Descending
510# ---------------------------------------------------------------------------
511
512PHONY += $(subdir-ym)
513$(subdir-ym):
514 $(Q)$(MAKE) $(build)=$@ \
515 $(if $(filter $@/, $(KBUILD_SINGLE_TARGETS)),single-build=) \
516 need-builtin=$(if $(filter $@/built-in.a, $(subdir-builtin)),1) \
517 need-modorder=$(if $(filter $@/modules.order, $(subdir-modorder)),1)
518
519# Add FORCE to the prequisites of a target to force it to be always rebuilt.
520# ---------------------------------------------------------------------------
521
522PHONY += FORCE
523
524FORCE:
525
526# Read all saved command lines and dependencies for the $(targets) we
527# may be building above, using $(if_changed{,_dep}). As an
528# optimization, we don't need to read them if the target does not
529# exist, we will rebuild anyway in that case.
530
531existing-targets := $(wildcard $(sort $(targets)))
532
533-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
534
535# Create directories for object files if they do not exist
536obj-dirs := $(sort $(patsubst %/,%, $(dir $(targets))))
537# If targets exist, their directories apparently exist. Skip mkdir.
538existing-dirs := $(sort $(patsubst %/,%, $(dir $(existing-targets))))
539obj-dirs := $(strip $(filter-out $(existing-dirs), $(obj-dirs)))
540ifneq ($(obj-dirs),)
541$(shell mkdir -p $(obj-dirs))
542endif
543
544.PHONY: $(PHONY)