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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)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
64include scripts/Makefile.host
65endif
66
67ifneq ($(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
84obj-y += $(obj)/lib-ksyms.o
85endif
86
87ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),)
88builtin-target := $(obj)/built-in.o
89endif
90
91modorder-target := $(obj)/modules.order
92
93# We keep a list of all modules in $(MODVERDIR)
94
95__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
96 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
97 $(subdir-ym) $(always)
98 @:
99
100# Linus' kernel sanity checking tool
101ifneq ($(KBUILD_CHECKSRC),0)
102 ifeq ($(KBUILD_CHECKSRC),2)
103 quiet_cmd_force_checksrc = CHECK $<
104 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
105 else
106 quiet_cmd_checksrc = CHECK $<
107 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
108 endif
109endif
110
111# Do section mismatch analysis for each module/built-in.o
112ifdef CONFIG_DEBUG_SECTION_MISMATCH
113 cmd_secanalysis = ; scripts/mod/modpost $@
114endif
115
116# Compile C sources (.c)
117# ---------------------------------------------------------------------------
118
119# Default is built-in, unless we know otherwise
120modkern_cflags = \
121 $(if $(part-of-module), \
122 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
123 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
124quiet_modtag := $(empty) $(empty)
125
126$(real-objs-m) : part-of-module := y
127$(real-objs-m:.o=.i) : part-of-module := y
128$(real-objs-m:.o=.s) : part-of-module := y
129$(real-objs-m:.o=.lst): part-of-module := y
130
131$(real-objs-m) : quiet_modtag := [M]
132$(real-objs-m:.o=.i) : quiet_modtag := [M]
133$(real-objs-m:.o=.s) : quiet_modtag := [M]
134$(real-objs-m:.o=.lst): quiet_modtag := [M]
135
136$(obj-m) : quiet_modtag := [M]
137
138# Default for not multi-part modules
139modname = $(basetarget)
140
141$(multi-objs-m) : modname = $(modname-multi)
142$(multi-objs-m:.o=.i) : modname = $(modname-multi)
143$(multi-objs-m:.o=.s) : modname = $(modname-multi)
144$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
145$(multi-objs-y) : modname = $(modname-multi)
146$(multi-objs-y:.o=.i) : modname = $(modname-multi)
147$(multi-objs-y:.o=.s) : modname = $(modname-multi)
148$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
149
150quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
151cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
152
153$(obj)/%.s: $(src)/%.c FORCE
154 $(call if_changed_dep,cc_s_c)
155
156quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
157cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
158
159$(obj)/%.i: $(src)/%.c FORCE
160 $(call if_changed_dep,cpp_i_c)
161
162# These mirror gensymtypes_S and co below, keep them in synch.
163cmd_gensymtypes_c = \
164 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
165 $(GENKSYMS) $(if $(1), -T $(2)) \
166 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
167 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
168 $(if $(KBUILD_PRESERVE),-p) \
169 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
170
171quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
172cmd_cc_symtypes_c = \
173 set -e; \
174 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
175 test -s $@ || rm -f $@
176
177$(obj)/%.symtypes : $(src)/%.c FORCE
178 $(call cmd,cc_symtypes_c)
179
180# C (.c) files
181# The C file is compiled and updated dependency information is generated.
182# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
183
184quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
185
186ifndef CONFIG_MODVERSIONS
187cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
188
189else
190# When module versioning is enabled the following steps are executed:
191# o compile a .tmp_<file>.o from <file>.c
192# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
193# not export symbols, we just rename .tmp_<file>.o to <file>.o and
194# are done.
195# o otherwise, we calculate symbol versions using the good old
196# genksyms on the preprocessed source and postprocess them in a way
197# that they are usable as a linker script
198# o generate <file>.o from .tmp_<file>.o using the linker to
199# replace the unresolved symbols __crc_exported_symbol with
200# the actual value of the checksum generated by genksyms
201
202cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
203
204cmd_modversions_c = \
205 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
206 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
207 > $(@D)/.tmp_$(@F:.o=.ver); \
208 \
209 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
210 -T $(@D)/.tmp_$(@F:.o=.ver); \
211 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
212 else \
213 mv -f $(@D)/.tmp_$(@F) $@; \
214 fi;
215endif
216
217ifdef CONFIG_FTRACE_MCOUNT_RECORD
218ifdef BUILD_C_RECORDMCOUNT
219ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
220 RECORDMCOUNT_FLAGS = -w
221endif
222# Due to recursion, we must skip empty.o.
223# The empty.o file is created in the make process in order to determine
224# the target endianness and word size. It is made before all other C
225# files, including recordmcount.
226sub_cmd_record_mcount = \
227 if [ $(@) != "scripts/mod/empty.o" ]; then \
228 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
229 fi;
230recordmcount_source := $(srctree)/scripts/recordmcount.c \
231 $(srctree)/scripts/recordmcount.h
232else
233sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
234 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
235 "$(if $(CONFIG_64BIT),64,32)" \
236 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
237 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
238 "$(if $(part-of-module),1,0)" "$(@)";
239recordmcount_source := $(srctree)/scripts/recordmcount.pl
240endif
241cmd_record_mcount = \
242 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
243 "$(CC_FLAGS_FTRACE)" ]; then \
244 $(sub_cmd_record_mcount) \
245 fi;
246endif
247
248ifdef CONFIG_STACK_VALIDATION
249ifneq ($(SKIP_STACK_VALIDATION),1)
250
251__objtool_obj := $(objtree)/tools/objtool/objtool
252
253objtool_args = check
254ifndef CONFIG_FRAME_POINTER
255objtool_args += --no-fp
256endif
257
258# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
259# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
260# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
261cmd_objtool = $(if $(patsubst y%,, \
262 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
263 $(__objtool_obj) $(objtool_args) "$(@)";)
264objtool_obj = $(if $(patsubst y%,, \
265 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
266 $(__objtool_obj))
267
268endif # SKIP_STACK_VALIDATION
269endif # CONFIG_STACK_VALIDATION
270
271define rule_cc_o_c
272 $(call echo-cmd,checksrc) $(cmd_checksrc) \
273 $(call cmd_and_fixdep,cc_o_c) \
274 $(cmd_modversions_c) \
275 $(cmd_objtool) \
276 $(call echo-cmd,record_mcount) $(cmd_record_mcount)
277endef
278
279define rule_as_o_S
280 $(call cmd_and_fixdep,as_o_S) \
281 $(cmd_modversions_S) \
282 $(cmd_objtool)
283endef
284
285# List module undefined symbols (or empty line if not enabled)
286ifdef CONFIG_TRIM_UNUSED_KSYMS
287cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo
288else
289cmd_undef_syms = echo
290endif
291
292# Built-in and composite module parts
293$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
294 $(call cmd,force_checksrc)
295 $(call if_changed_rule,cc_o_c)
296
297# Single-part modules are special since we need to mark them in $(MODVERDIR)
298
299$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE
300 $(call cmd,force_checksrc)
301 $(call if_changed_rule,cc_o_c)
302 @{ echo $(@:.o=.ko); echo $@; \
303 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
304
305quiet_cmd_cc_lst_c = MKLST $@
306 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
307 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
308 System.map $(OBJDUMP) > $@
309
310$(obj)/%.lst: $(src)/%.c FORCE
311 $(call if_changed_dep,cc_lst_c)
312
313# Compile assembler sources (.S)
314# ---------------------------------------------------------------------------
315
316modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
317
318$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
319$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
320
321# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
322# or a file that it includes, in order to get versioned symbols. We build a
323# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
324# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
325#
326# This is convoluted. The .S file must first be preprocessed to run guards and
327# expand names, then the resulting exports must be constructed into plain
328# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
329# to make the genksyms input.
330#
331# These mirror gensymtypes_c and co above, keep them in synch.
332cmd_gensymtypes_S = \
333 (echo "\#include <linux/kernel.h>" ; \
334 echo "\#include <asm/asm-prototypes.h>" ; \
335 $(CPP) $(a_flags) $< | \
336 grep "\<___EXPORT_SYMBOL\>" | \
337 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
338 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
339 $(GENKSYMS) $(if $(1), -T $(2)) \
340 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
341 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
342 $(if $(KBUILD_PRESERVE),-p) \
343 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
344
345quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
346cmd_cc_symtypes_S = \
347 set -e; \
348 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
349 test -s $@ || rm -f $@
350
351$(obj)/%.symtypes : $(src)/%.S FORCE
352 $(call cmd,cc_symtypes_S)
353
354
355quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
356cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
357
358$(obj)/%.s: $(src)/%.S FORCE
359 $(call if_changed_dep,cpp_s_S)
360
361quiet_cmd_as_o_S = AS $(quiet_modtag) $@
362
363ifndef CONFIG_MODVERSIONS
364cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
365
366else
367
368ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
369
370ifeq ($(ASM_PROTOTYPES),)
371cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
372
373else
374
375# versioning matches the C process described above, with difference that
376# we parse asm-prototypes.h C header to get function definitions.
377
378cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
379
380cmd_modversions_S = \
381 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
382 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
383 > $(@D)/.tmp_$(@F:.o=.ver); \
384 \
385 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
386 -T $(@D)/.tmp_$(@F:.o=.ver); \
387 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
388 else \
389 mv -f $(@D)/.tmp_$(@F) $@; \
390 fi;
391endif
392endif
393
394$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE
395 $(call if_changed_rule,as_o_S)
396
397targets += $(real-objs-y) $(real-objs-m) $(lib-y)
398targets += $(extra-y) $(MAKECMDGOALS) $(always)
399
400# Linker scripts preprocessor (.lds.S -> .lds)
401# ---------------------------------------------------------------------------
402quiet_cmd_cpp_lds_S = LDS $@
403 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
404 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
405
406$(obj)/%.lds: $(src)/%.lds.S FORCE
407 $(call if_changed_dep,cpp_lds_S)
408
409# ASN.1 grammar
410# ---------------------------------------------------------------------------
411quiet_cmd_asn1_compiler = ASN.1 $@
412 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
413 $(subst .h,.c,$@) $(subst .c,.h,$@)
414
415.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
416
417$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
418 $(call cmd,asn1_compiler)
419
420# Build the compiled-in targets
421# ---------------------------------------------------------------------------
422
423# To build objects in subdirs, we need to descend into the directories
424$(sort $(subdir-obj-y)): $(subdir-ym) ;
425
426#
427# Rule to compile a set of .o files into one .o file
428#
429ifdef builtin-target
430
431ifdef CONFIG_THIN_ARCHIVES
432 cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
433 cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS)
434 quiet_cmd_link_o_target = AR $@
435else
436 cmd_make_builtin = $(LD) $(ld_flags) -r -o
437 cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS)
438 quiet_cmd_link_o_target = LD $@
439endif
440
441# If the list of objects to link is empty, just create an empty built-in.o
442cmd_link_o_target = $(if $(strip $(obj-y)),\
443 $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \
444 $(cmd_secanalysis),\
445 $(cmd_make_empty_builtin) $@)
446
447$(builtin-target): $(obj-y) FORCE
448 $(call if_changed,link_o_target)
449
450targets += $(builtin-target)
451endif # builtin-target
452
453#
454# Rule to create modules.order file
455#
456# Create commands to either record .ko file or cat modules.order from
457# a subdirectory
458modorder-cmds = \
459 $(foreach m, $(modorder), \
460 $(if $(filter %/modules.order, $m), \
461 cat $m;, echo kernel/$m;))
462
463$(modorder-target): $(subdir-ym) FORCE
464 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
465
466#
467# Rule to compile a set of .o files into one .a file
468#
469ifdef lib-target
470quiet_cmd_link_l_target = AR $@
471
472ifdef CONFIG_THIN_ARCHIVES
473 cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y)
474else
475 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
476endif
477
478$(lib-target): $(lib-y) FORCE
479 $(call if_changed,link_l_target)
480
481targets += $(lib-target)
482
483dummy-object = $(obj)/.lib_exports.o
484ksyms-lds = $(dot-target).lds
485ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
486ref_prefix = EXTERN(_
487else
488ref_prefix = EXTERN(
489endif
490
491quiet_cmd_export_list = EXPORTS $@
492cmd_export_list = $(OBJDUMP) -h $< | \
493 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
494 rm -f $(dummy-object);\
495 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
496 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
497 rm $(dummy-object) $(ksyms-lds)
498
499$(obj)/lib-ksyms.o: $(lib-target) FORCE
500 $(call if_changed,export_list)
501
502targets += $(obj)/lib-ksyms.o
503
504endif
505
506#
507# Rule to link composite objects
508#
509# Composite objects are specified in kbuild makefile as follows:
510# <composite-object>-objs := <list of .o files>
511# or
512# <composite-object>-y := <list of .o files>
513# or
514# <composite-object>-m := <list of .o files>
515# The -m syntax only works if <composite object> is a module
516link_multi_deps = \
517$(filter $(addprefix $(obj)/, \
518$($(subst $(obj)/,,$(@:.o=-objs))) \
519$($(subst $(obj)/,,$(@:.o=-y))) \
520$($(subst $(obj)/,,$(@:.o=-m)))), $^)
521
522cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
523
524ifdef CONFIG_THIN_ARCHIVES
525 quiet_cmd_link_multi-y = AR $@
526 cmd_link_multi-y = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) $@ $(link_multi_deps)
527else
528 quiet_cmd_link_multi-y = LD $@
529 cmd_link_multi-y = $(cmd_link_multi-link)
530endif
531
532quiet_cmd_link_multi-m = LD [M] $@
533cmd_link_multi-m = $(cmd_link_multi-link)
534
535$(multi-used-y): FORCE
536 $(call if_changed,link_multi-y)
537$(call multi_depend, $(multi-used-y), .o, -objs -y)
538
539$(multi-used-m): FORCE
540 $(call if_changed,link_multi-m)
541 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \
542 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
543$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
544
545targets += $(multi-used-y) $(multi-used-m)
546
547
548# Descending
549# ---------------------------------------------------------------------------
550
551PHONY += $(subdir-ym)
552$(subdir-ym):
553 $(Q)$(MAKE) $(build)=$@
554
555# Add FORCE to the prequisites of a target to force it to be always rebuilt.
556# ---------------------------------------------------------------------------
557
558PHONY += FORCE
559
560FORCE:
561
562# Read all saved command lines and dependencies for the $(targets) we
563# may be building above, using $(if_changed{,_dep}). As an
564# optimization, we don't need to read them if the target does not
565# exist, we will rebuild anyway in that case.
566
567targets := $(wildcard $(sort $(targets)))
568cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
569
570ifneq ($(cmd_files),)
571 include $(cmd_files)
572endif
573
574# Declare the contents of the .PHONY variable as phony. We keep that
575# information in a variable se we can use it in if_changed and friends.
576
577.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
53#
54# make W=... settings
55#
56# W=1 - warnings that may be relevant and does not occur too often
57# W=2 - warnings that occur quite often but may still be relevant
58# W=3 - the more obscure warnings, can most likely be ignored
59#
60# $(call cc-option, -W...) handles gcc -W.. options which
61# are not supported by all versions of the compiler
62ifdef KBUILD_ENABLE_EXTRA_GCC_CHECKS
63warning- := $(empty)
64
65warning-1 := -Wextra -Wunused -Wno-unused-parameter
66warning-1 += -Wmissing-declarations
67warning-1 += -Wmissing-format-attribute
68warning-1 += $(call cc-option, -Wmissing-prototypes)
69warning-1 += -Wold-style-definition
70warning-1 += $(call cc-option, -Wmissing-include-dirs)
71warning-1 += $(call cc-option, -Wunused-but-set-variable)
72warning-1 += $(call cc-disable-warning, missing-field-initializers)
73
74# Clang
75warning-1 += $(call cc-disable-warning, initializer-overrides)
76warning-1 += $(call cc-disable-warning, unused-value)
77warning-1 += $(call cc-disable-warning, format)
78warning-1 += $(call cc-disable-warning, unknown-warning-option)
79warning-1 += $(call cc-disable-warning, sign-compare)
80warning-1 += $(call cc-disable-warning, format-zero-length)
81warning-1 += $(call cc-disable-warning, uninitialized)
82warning-1 += $(call cc-option, -fcatch-undefined-behavior)
83
84warning-2 := -Waggregate-return
85warning-2 += -Wcast-align
86warning-2 += -Wdisabled-optimization
87warning-2 += -Wnested-externs
88warning-2 += -Wshadow
89warning-2 += $(call cc-option, -Wlogical-op)
90warning-2 += $(call cc-option, -Wmissing-field-initializers)
91
92warning-3 := -Wbad-function-cast
93warning-3 += -Wcast-qual
94warning-3 += -Wconversion
95warning-3 += -Wpacked
96warning-3 += -Wpadded
97warning-3 += -Wpointer-arith
98warning-3 += -Wredundant-decls
99warning-3 += -Wswitch-default
100warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
101warning-3 += $(call cc-option, -Wvla)
102
103warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
104warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
105warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
106
107ifeq ("$(strip $(warning))","")
108 $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
109endif
110
111KBUILD_CFLAGS += $(warning)
112endif
113
114include scripts/Makefile.lib
115
116ifdef host-progs
117ifneq ($(hostprogs-y),$(host-progs))
118$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
119hostprogs-y += $(host-progs)
120endif
121endif
122
123# Do not include host rules unless needed
124ifneq ($(hostprogs-y)$(hostprogs-m),)
125include scripts/Makefile.host
126endif
127
128ifneq ($(KBUILD_SRC),)
129# Create output directory if not already present
130_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
131
132# Create directories for object files if directory does not exist
133# Needed when obj-y := dir/file.o syntax is used
134_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
135endif
136
137ifndef obj
138$(warning kbuild: Makefile.build is included improperly)
139endif
140
141# ===========================================================================
142
143ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
144lib-target := $(obj)/lib.a
145endif
146
147ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
148builtin-target := $(obj)/built-in.o
149endif
150
151modorder-target := $(obj)/modules.order
152
153# We keep a list of all modules in $(MODVERDIR)
154
155__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
156 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
157 $(subdir-ym) $(always)
158 @:
159
160# Linus' kernel sanity checking tool
161ifneq ($(KBUILD_CHECKSRC),0)
162 ifeq ($(KBUILD_CHECKSRC),2)
163 quiet_cmd_force_checksrc = CHECK $<
164 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
165 else
166 quiet_cmd_checksrc = CHECK $<
167 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
168 endif
169endif
170
171# Do section mismatch analysis for each module/built-in.o
172ifdef CONFIG_DEBUG_SECTION_MISMATCH
173 cmd_secanalysis = ; scripts/mod/modpost $@
174endif
175
176# Compile C sources (.c)
177# ---------------------------------------------------------------------------
178
179# Default is built-in, unless we know otherwise
180modkern_cflags = \
181 $(if $(part-of-module), \
182 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
183 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
184quiet_modtag := $(empty) $(empty)
185
186$(real-objs-m) : part-of-module := y
187$(real-objs-m:.o=.i) : part-of-module := y
188$(real-objs-m:.o=.s) : part-of-module := y
189$(real-objs-m:.o=.lst): part-of-module := y
190
191$(real-objs-m) : quiet_modtag := [M]
192$(real-objs-m:.o=.i) : quiet_modtag := [M]
193$(real-objs-m:.o=.s) : quiet_modtag := [M]
194$(real-objs-m:.o=.lst): quiet_modtag := [M]
195
196$(obj-m) : quiet_modtag := [M]
197
198# Default for not multi-part modules
199modname = $(basetarget)
200
201$(multi-objs-m) : modname = $(modname-multi)
202$(multi-objs-m:.o=.i) : modname = $(modname-multi)
203$(multi-objs-m:.o=.s) : modname = $(modname-multi)
204$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
205$(multi-objs-y) : modname = $(modname-multi)
206$(multi-objs-y:.o=.i) : modname = $(modname-multi)
207$(multi-objs-y:.o=.s) : modname = $(modname-multi)
208$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
209
210quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
211cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
212
213$(obj)/%.s: $(src)/%.c FORCE
214 $(call if_changed_dep,cc_s_c)
215
216quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
217cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
218
219$(obj)/%.i: $(src)/%.c FORCE
220 $(call if_changed_dep,cc_i_c)
221
222cmd_gensymtypes = \
223 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
224 $(GENKSYMS) $(if $(1), -T $(2)) \
225 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
226 $(if $(KBUILD_PRESERVE),-p) \
227 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
228
229quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
230cmd_cc_symtypes_c = \
231 set -e; \
232 $(call cmd_gensymtypes,true,$@) >/dev/null; \
233 test -s $@ || rm -f $@
234
235$(obj)/%.symtypes : $(src)/%.c FORCE
236 $(call cmd,cc_symtypes_c)
237
238# C (.c) files
239# The C file is compiled and updated dependency information is generated.
240# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
241
242quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
243
244ifndef CONFIG_MODVERSIONS
245cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
246
247else
248# When module versioning is enabled the following steps are executed:
249# o compile a .tmp_<file>.o from <file>.c
250# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
251# not export symbols, we just rename .tmp_<file>.o to <file>.o and
252# are done.
253# o otherwise, we calculate symbol versions using the good old
254# genksyms on the preprocessed source and postprocess them in a way
255# that they are usable as a linker script
256# o generate <file>.o from .tmp_<file>.o using the linker to
257# replace the unresolved symbols __crc_exported_symbol with
258# the actual value of the checksum generated by genksyms
259
260cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
261cmd_modversions = \
262 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
263 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
264 > $(@D)/.tmp_$(@F:.o=.ver); \
265 \
266 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
267 -T $(@D)/.tmp_$(@F:.o=.ver); \
268 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
269 else \
270 mv -f $(@D)/.tmp_$(@F) $@; \
271 fi;
272endif
273
274ifdef CONFIG_FTRACE_MCOUNT_RECORD
275ifdef BUILD_C_RECORDMCOUNT
276ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
277 RECORDMCOUNT_FLAGS = -w
278endif
279# Due to recursion, we must skip empty.o.
280# The empty.o file is created in the make process in order to determine
281# the target endianness and word size. It is made before all other C
282# files, including recordmcount.
283sub_cmd_record_mcount = \
284 if [ $(@) != "scripts/mod/empty.o" ]; then \
285 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
286 fi;
287recordmcount_source := $(srctree)/scripts/recordmcount.c \
288 $(srctree)/scripts/recordmcount.h
289else
290sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
291 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
292 "$(if $(CONFIG_64BIT),64,32)" \
293 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
294 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
295 "$(if $(part-of-module),1,0)" "$(@)";
296recordmcount_source := $(srctree)/scripts/recordmcount.pl
297endif
298cmd_record_mcount = \
299 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
300 $(sub_cmd_record_mcount) \
301 fi;
302endif
303
304define rule_cc_o_c
305 $(call echo-cmd,checksrc) $(cmd_checksrc) \
306 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
307 $(cmd_modversions) \
308 $(call echo-cmd,record_mcount) \
309 $(cmd_record_mcount) \
310 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
311 $(dot-target).tmp; \
312 rm -f $(depfile); \
313 mv -f $(dot-target).tmp $(dot-target).cmd
314endef
315
316# Built-in and composite module parts
317$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
318 $(call cmd,force_checksrc)
319 $(call if_changed_rule,cc_o_c)
320
321# Single-part modules are special since we need to mark them in $(MODVERDIR)
322
323$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
324 $(call cmd,force_checksrc)
325 $(call if_changed_rule,cc_o_c)
326 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
327
328quiet_cmd_cc_lst_c = MKLST $@
329 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
330 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
331 System.map $(OBJDUMP) > $@
332
333$(obj)/%.lst: $(src)/%.c FORCE
334 $(call if_changed_dep,cc_lst_c)
335
336# Compile assembler sources (.S)
337# ---------------------------------------------------------------------------
338
339modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
340
341$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
342$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
343
344quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
345cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
346
347$(obj)/%.s: $(src)/%.S FORCE
348 $(call if_changed_dep,as_s_S)
349
350quiet_cmd_as_o_S = AS $(quiet_modtag) $@
351cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
352
353$(obj)/%.o: $(src)/%.S FORCE
354 $(call if_changed_dep,as_o_S)
355
356targets += $(real-objs-y) $(real-objs-m) $(lib-y)
357targets += $(extra-y) $(MAKECMDGOALS) $(always)
358
359# Linker scripts preprocessor (.lds.S -> .lds)
360# ---------------------------------------------------------------------------
361quiet_cmd_cpp_lds_S = LDS $@
362 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
363 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
364
365$(obj)/%.lds: $(src)/%.lds.S FORCE
366 $(call if_changed_dep,cpp_lds_S)
367
368# ASN.1 grammar
369# ---------------------------------------------------------------------------
370quiet_cmd_asn1_compiler = ASN.1 $@
371 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
372 $(subst .h,.c,$@) $(subst .c,.h,$@)
373
374.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h
375
376$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
377 $(call cmd,asn1_compiler)
378
379# Build the compiled-in targets
380# ---------------------------------------------------------------------------
381
382# To build objects in subdirs, we need to descend into the directories
383$(sort $(subdir-obj-y)): $(subdir-ym) ;
384
385#
386# Rule to compile a set of .o files into one .o file
387#
388ifdef builtin-target
389quiet_cmd_link_o_target = LD $@
390# If the list of objects to link is empty, just create an empty built-in.o
391cmd_link_o_target = $(if $(strip $(obj-y)),\
392 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
393 $(cmd_secanalysis),\
394 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
395
396$(builtin-target): $(obj-y) FORCE
397 $(call if_changed,link_o_target)
398
399targets += $(builtin-target)
400endif # builtin-target
401
402#
403# Rule to create modules.order file
404#
405# Create commands to either record .ko file or cat modules.order from
406# a subdirectory
407modorder-cmds = \
408 $(foreach m, $(modorder), \
409 $(if $(filter %/modules.order, $m), \
410 cat $m;, echo kernel/$m;))
411
412$(modorder-target): $(subdir-ym) FORCE
413 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
414
415#
416# Rule to compile a set of .o files into one .a file
417#
418ifdef lib-target
419quiet_cmd_link_l_target = AR $@
420cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
421
422$(lib-target): $(lib-y) FORCE
423 $(call if_changed,link_l_target)
424
425targets += $(lib-target)
426endif
427
428#
429# Rule to link composite objects
430#
431# Composite objects are specified in kbuild makefile as follows:
432# <composite-object>-objs := <list of .o files>
433# or
434# <composite-object>-y := <list of .o files>
435link_multi_deps = \
436$(filter $(addprefix $(obj)/, \
437$($(subst $(obj)/,,$(@:.o=-objs))) \
438$($(subst $(obj)/,,$(@:.o=-y)))), $^)
439
440quiet_cmd_link_multi-y = LD $@
441cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
442
443quiet_cmd_link_multi-m = LD [M] $@
444cmd_link_multi-m = $(cmd_link_multi-y)
445
446# We would rather have a list of rules like
447# foo.o: $(foo-objs)
448# but that's not so easy, so we rather make all composite objects depend
449# on the set of all their parts
450$(multi-used-y) : %.o: $(multi-objs-y) FORCE
451 $(call if_changed,link_multi-y)
452
453$(multi-used-m) : %.o: $(multi-objs-m) FORCE
454 $(call if_changed,link_multi-m)
455 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
456
457targets += $(multi-used-y) $(multi-used-m)
458
459
460# Descending
461# ---------------------------------------------------------------------------
462
463PHONY += $(subdir-ym)
464$(subdir-ym):
465 $(Q)$(MAKE) $(build)=$@
466
467# Add FORCE to the prequisites of a target to force it to be always rebuilt.
468# ---------------------------------------------------------------------------
469
470PHONY += FORCE
471
472FORCE:
473
474# Read all saved command lines and dependencies for the $(targets) we
475# may be building above, using $(if_changed{,_dep}). As an
476# optimization, we don't need to read them if the target does not
477# exist, we will rebuild anyway in that case.
478
479targets := $(wildcard $(sort $(targets)))
480cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
481
482ifneq ($(cmd_files),)
483 include $(cmd_files)
484endif
485
486# Declare the contents of the .PHONY variable as phony. We keep that
487# information in a variable se we can use it in if_changed and friends.
488
489.PHONY: $(PHONY)