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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# ==========================================================================
2# Building
3# ==========================================================================
4
5src := $(obj)
6
7PHONY := __build
8__build:
9
10# Init all relevant variables used in kbuild files so
11# 1) they have correct type
12# 2) they do not inherit any value from the environment
13obj-y :=
14obj-m :=
15lib-y :=
16lib-m :=
17always :=
18targets :=
19subdir-y :=
20subdir-m :=
21EXTRA_AFLAGS :=
22EXTRA_CFLAGS :=
23EXTRA_CPPFLAGS :=
24EXTRA_LDFLAGS :=
25asflags-y :=
26ccflags-y :=
27cppflags-y :=
28ldflags-y :=
29
30subdir-asflags-y :=
31subdir-ccflags-y :=
32
33# Read auto.conf if it exists, otherwise ignore
34-include include/config/auto.conf
35
36include scripts/Kbuild.include
37
38# For backward compatibility check that these variables do not change
39save-cflags := $(CFLAGS)
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 $(kbuild-file)
45
46# If the save-* variables changed error out
47ifeq ($(KBUILD_NOPEDANTIC),)
48 ifneq ("$(save-cflags)","$(CFLAGS)")
49 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
50 endif
51endif
52
53include scripts/Makefile.lib
54
55ifdef host-progs
56ifneq ($(hostprogs-y),$(host-progs))
57$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
58hostprogs-y += $(host-progs)
59endif
60endif
61
62# Do not include host rules unless needed
63ifneq ($(hostprogs-y)$(hostprogs-m),)
64include scripts/Makefile.host
65endif
66
67ifneq ($(KBUILD_SRC),)
68# Create output directory if not already present
69_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
70
71# Create directories for object files if directory does not exist
72# Needed when obj-y := dir/file.o syntax is used
73_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
74endif
75
76ifndef obj
77$(warning kbuild: Makefile.build is included improperly)
78endif
79
80# ===========================================================================
81
82ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
83lib-target := $(obj)/lib.a
84endif
85
86ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
87builtin-target := $(obj)/built-in.o
88endif
89
90modorder-target := $(obj)/modules.order
91
92# We keep a list of all modules in $(MODVERDIR)
93
94__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
95 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
96 $(subdir-ym) $(always)
97 @:
98
99# Linus' kernel sanity checking tool
100ifneq ($(KBUILD_CHECKSRC),0)
101 ifeq ($(KBUILD_CHECKSRC),2)
102 quiet_cmd_force_checksrc = CHECK $<
103 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
104 else
105 quiet_cmd_checksrc = CHECK $<
106 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
107 endif
108endif
109
110# Do section mismatch analysis for each module/built-in.o
111ifdef CONFIG_DEBUG_SECTION_MISMATCH
112 cmd_secanalysis = ; scripts/mod/modpost $@
113endif
114
115# Compile C sources (.c)
116# ---------------------------------------------------------------------------
117
118# Default is built-in, unless we know otherwise
119modkern_cflags = \
120 $(if $(part-of-module), \
121 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
122 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
123quiet_modtag := $(empty) $(empty)
124
125$(real-objs-m) : part-of-module := y
126$(real-objs-m:.o=.i) : part-of-module := y
127$(real-objs-m:.o=.s) : part-of-module := y
128$(real-objs-m:.o=.lst): part-of-module := y
129
130$(real-objs-m) : quiet_modtag := [M]
131$(real-objs-m:.o=.i) : quiet_modtag := [M]
132$(real-objs-m:.o=.s) : quiet_modtag := [M]
133$(real-objs-m:.o=.lst): quiet_modtag := [M]
134
135$(obj-m) : quiet_modtag := [M]
136
137# Default for not multi-part modules
138modname = $(basetarget)
139
140$(multi-objs-m) : modname = $(modname-multi)
141$(multi-objs-m:.o=.i) : modname = $(modname-multi)
142$(multi-objs-m:.o=.s) : modname = $(modname-multi)
143$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
144$(multi-objs-y) : modname = $(modname-multi)
145$(multi-objs-y:.o=.i) : modname = $(modname-multi)
146$(multi-objs-y:.o=.s) : modname = $(modname-multi)
147$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
148
149quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
150cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
151
152$(obj)/%.s: $(src)/%.c FORCE
153 $(call if_changed_dep,cc_s_c)
154
155quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
156cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
157
158$(obj)/%.i: $(src)/%.c FORCE
159 $(call if_changed_dep,cc_i_c)
160
161cmd_gensymtypes = \
162 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
163 $(GENKSYMS) $(if $(1), -T $(2)) \
164 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
165 $(if $(KBUILD_PRESERVE),-p) \
166 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
167
168quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
169cmd_cc_symtypes_c = \
170 set -e; \
171 $(call cmd_gensymtypes,true,$@) >/dev/null; \
172 test -s $@ || rm -f $@
173
174$(obj)/%.symtypes : $(src)/%.c FORCE
175 $(call cmd,cc_symtypes_c)
176
177# C (.c) files
178# The C file is compiled and updated dependency information is generated.
179# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
180
181quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
182
183ifndef CONFIG_MODVERSIONS
184cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
185
186else
187# When module versioning is enabled the following steps are executed:
188# o compile a .tmp_<file>.o from <file>.c
189# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
190# not export symbols, we just rename .tmp_<file>.o to <file>.o and
191# are done.
192# o otherwise, we calculate symbol versions using the good old
193# genksyms on the preprocessed source and postprocess them in a way
194# that they are usable as a linker script
195# o generate <file>.o from .tmp_<file>.o using the linker to
196# replace the unresolved symbols __crc_exported_symbol with
197# the actual value of the checksum generated by genksyms
198
199cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
200cmd_modversions = \
201 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
202 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
203 > $(@D)/.tmp_$(@F:.o=.ver); \
204 \
205 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
206 -T $(@D)/.tmp_$(@F:.o=.ver); \
207 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
208 else \
209 mv -f $(@D)/.tmp_$(@F) $@; \
210 fi;
211endif
212
213ifdef CONFIG_FTRACE_MCOUNT_RECORD
214ifdef BUILD_C_RECORDMCOUNT
215ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
216 RECORDMCOUNT_FLAGS = -w
217endif
218# Due to recursion, we must skip empty.o.
219# The empty.o file is created in the make process in order to determine
220# the target endianness and word size. It is made before all other C
221# files, including recordmcount.
222sub_cmd_record_mcount = \
223 if [ $(@) != "scripts/mod/empty.o" ]; then \
224 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
225 fi;
226recordmcount_source := $(srctree)/scripts/recordmcount.c \
227 $(srctree)/scripts/recordmcount.h
228else
229sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
230 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
231 "$(if $(CONFIG_64BIT),64,32)" \
232 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
233 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
234 "$(if $(part-of-module),1,0)" "$(@)";
235recordmcount_source := $(srctree)/scripts/recordmcount.pl
236endif
237cmd_record_mcount = \
238 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
239 "$(CC_FLAGS_FTRACE)" ]; then \
240 $(sub_cmd_record_mcount) \
241 fi;
242endif
243
244ifdef CONFIG_STACK_VALIDATION
245ifneq ($(SKIP_STACK_VALIDATION),1)
246
247__objtool_obj := $(objtree)/tools/objtool/objtool
248
249objtool_args = check
250ifndef CONFIG_FRAME_POINTER
251objtool_args += --no-fp
252endif
253
254# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
255# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
256# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
257cmd_objtool = $(if $(patsubst y%,, \
258 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
259 $(__objtool_obj) $(objtool_args) "$(@)";)
260objtool_obj = $(if $(patsubst y%,, \
261 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
262 $(__objtool_obj))
263
264endif # SKIP_STACK_VALIDATION
265endif # CONFIG_STACK_VALIDATION
266
267define rule_cc_o_c
268 $(call echo-cmd,checksrc) $(cmd_checksrc) \
269 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
270 $(cmd_modversions) \
271 $(cmd_objtool) \
272 $(call echo-cmd,record_mcount) \
273 $(cmd_record_mcount) \
274 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
275 $(dot-target).tmp; \
276 rm -f $(depfile); \
277 mv -f $(dot-target).tmp $(dot-target).cmd
278endef
279
280define rule_as_o_S
281 $(call echo-cmd,as_o_S) $(cmd_as_o_S); \
282 $(cmd_objtool) \
283 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,as_o_S)' > \
284 $(dot-target).tmp; \
285 rm -f $(depfile); \
286 mv -f $(dot-target).tmp $(dot-target).cmd
287endef
288
289# Built-in and composite module parts
290$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
291 $(call cmd,force_checksrc)
292 $(call if_changed_rule,cc_o_c)
293
294# Single-part modules are special since we need to mark them in $(MODVERDIR)
295
296$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
297 $(call cmd,force_checksrc)
298 $(call if_changed_rule,cc_o_c)
299 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
300
301quiet_cmd_cc_lst_c = MKLST $@
302 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
303 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
304 System.map $(OBJDUMP) > $@
305
306$(obj)/%.lst: $(src)/%.c FORCE
307 $(call if_changed_dep,cc_lst_c)
308
309# Compile assembler sources (.S)
310# ---------------------------------------------------------------------------
311
312modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
313
314$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
315$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
316
317quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
318cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
319
320$(obj)/%.s: $(src)/%.S FORCE
321 $(call if_changed_dep,as_s_S)
322
323quiet_cmd_as_o_S = AS $(quiet_modtag) $@
324cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
325
326$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE
327 $(call if_changed_rule,as_o_S)
328
329targets += $(real-objs-y) $(real-objs-m) $(lib-y)
330targets += $(extra-y) $(MAKECMDGOALS) $(always)
331
332# Linker scripts preprocessor (.lds.S -> .lds)
333# ---------------------------------------------------------------------------
334quiet_cmd_cpp_lds_S = LDS $@
335 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
336 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
337
338$(obj)/%.lds: $(src)/%.lds.S FORCE
339 $(call if_changed_dep,cpp_lds_S)
340
341# ASN.1 grammar
342# ---------------------------------------------------------------------------
343quiet_cmd_asn1_compiler = ASN.1 $@
344 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
345 $(subst .h,.c,$@) $(subst .c,.h,$@)
346
347.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
348
349$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
350 $(call cmd,asn1_compiler)
351
352# Build the compiled-in targets
353# ---------------------------------------------------------------------------
354
355# To build objects in subdirs, we need to descend into the directories
356$(sort $(subdir-obj-y)): $(subdir-ym) ;
357
358#
359# Rule to compile a set of .o files into one .o file
360#
361ifdef builtin-target
362quiet_cmd_link_o_target = LD $@
363# If the list of objects to link is empty, just create an empty built-in.o
364cmd_link_o_target = $(if $(strip $(obj-y)),\
365 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
366 $(cmd_secanalysis),\
367 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
368
369$(builtin-target): $(obj-y) FORCE
370 $(call if_changed,link_o_target)
371
372targets += $(builtin-target)
373endif # builtin-target
374
375#
376# Rule to create modules.order file
377#
378# Create commands to either record .ko file or cat modules.order from
379# a subdirectory
380modorder-cmds = \
381 $(foreach m, $(modorder), \
382 $(if $(filter %/modules.order, $m), \
383 cat $m;, echo kernel/$m;))
384
385$(modorder-target): $(subdir-ym) FORCE
386 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
387
388#
389# Rule to compile a set of .o files into one .a file
390#
391ifdef lib-target
392quiet_cmd_link_l_target = AR $@
393cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
394
395$(lib-target): $(lib-y) FORCE
396 $(call if_changed,link_l_target)
397
398targets += $(lib-target)
399endif
400
401#
402# Rule to link composite objects
403#
404# Composite objects are specified in kbuild makefile as follows:
405# <composite-object>-objs := <list of .o files>
406# or
407# <composite-object>-y := <list of .o files>
408# or
409# <composite-object>-m := <list of .o files>
410# The -m syntax only works if <composite object> is a module
411link_multi_deps = \
412$(filter $(addprefix $(obj)/, \
413$($(subst $(obj)/,,$(@:.o=-objs))) \
414$($(subst $(obj)/,,$(@:.o=-y))) \
415$($(subst $(obj)/,,$(@:.o=-m)))), $^)
416
417quiet_cmd_link_multi-y = LD $@
418cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
419
420quiet_cmd_link_multi-m = LD [M] $@
421cmd_link_multi-m = $(cmd_link_multi-y)
422
423$(multi-used-y): FORCE
424 $(call if_changed,link_multi-y)
425$(call multi_depend, $(multi-used-y), .o, -objs -y)
426
427$(multi-used-m): FORCE
428 $(call if_changed,link_multi-m)
429 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
430$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
431
432targets += $(multi-used-y) $(multi-used-m)
433
434
435# Descending
436# ---------------------------------------------------------------------------
437
438PHONY += $(subdir-ym)
439$(subdir-ym):
440 $(Q)$(MAKE) $(build)=$@
441
442# Add FORCE to the prequisites of a target to force it to be always rebuilt.
443# ---------------------------------------------------------------------------
444
445PHONY += FORCE
446
447FORCE:
448
449# Read all saved command lines and dependencies for the $(targets) we
450# may be building above, using $(if_changed{,_dep}). As an
451# optimization, we don't need to read them if the target does not
452# exist, we will rebuild anyway in that case.
453
454targets := $(wildcard $(sort $(targets)))
455cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
456
457ifneq ($(cmd_files),)
458 include $(cmd_files)
459endif
460
461# Declare the contents of the .PHONY variable as phony. We keep that
462# information in a variable se we can use it in if_changed and friends.
463
464.PHONY: $(PHONY)