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1# SPDX-License-Identifier: GPL-2.0
2# ==========================================================================
3# Building
4# ==========================================================================
5
6src := $(obj)
7
8PHONY := __build
9__build:
10
11# Init all relevant variables used in kbuild files so
12# 1) they have correct type
13# 2) they do not inherit any value from the environment
14obj-y :=
15obj-m :=
16lib-y :=
17lib-m :=
18always :=
19targets :=
20subdir-y :=
21subdir-m :=
22EXTRA_AFLAGS :=
23EXTRA_CFLAGS :=
24EXTRA_CPPFLAGS :=
25EXTRA_LDFLAGS :=
26asflags-y :=
27ccflags-y :=
28cppflags-y :=
29ldflags-y :=
30
31subdir-asflags-y :=
32subdir-ccflags-y :=
33
34# Read auto.conf if it exists, otherwise ignore
35-include include/config/auto.conf
36
37include scripts/Kbuild.include
38
39# For backward compatibility check that these variables do not change
40save-cflags := $(CFLAGS)
41
42# The filename Kbuild has precedence over Makefile
43kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
44kbuild-file := $(if $(wildcard $(kbuild-dir)/Kbuild),$(kbuild-dir)/Kbuild,$(kbuild-dir)/Makefile)
45include $(kbuild-file)
46
47# If the save-* variables changed error out
48ifeq ($(KBUILD_NOPEDANTIC),)
49 ifneq ("$(save-cflags)","$(CFLAGS)")
50 $(error CFLAGS was changed in "$(kbuild-file)". Fix it to use ccflags-y)
51 endif
52endif
53
54include scripts/Makefile.lib
55
56ifdef host-progs
57ifneq ($(hostprogs-y),$(host-progs))
58$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
59hostprogs-y += $(host-progs)
60endif
61endif
62
63# Do not include host rules unless needed
64ifneq ($(hostprogs-y)$(hostprogs-m)$(hostlibs-y)$(hostlibs-m)$(hostcxxlibs-y)$(hostcxxlibs-m),)
65include scripts/Makefile.host
66endif
67
68ifndef obj
69$(warning kbuild: Makefile.build is included improperly)
70endif
71
72# ===========================================================================
73
74ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),)
75lib-target := $(obj)/lib.a
76real-obj-y += $(obj)/lib-ksyms.o
77endif
78
79ifneq ($(strip $(real-obj-y) $(need-builtin)),)
80builtin-target := $(obj)/built-in.a
81endif
82
83modorder-target := $(obj)/modules.order
84
85# We keep a list of all modules in $(MODVERDIR)
86
87__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
88 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
89 $(subdir-ym) $(always)
90 @:
91
92# Linus' kernel sanity checking tool
93ifneq ($(KBUILD_CHECKSRC),0)
94 ifeq ($(KBUILD_CHECKSRC),2)
95 quiet_cmd_force_checksrc = CHECK $<
96 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
97 else
98 quiet_cmd_checksrc = CHECK $<
99 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
100 endif
101endif
102
103ifneq ($(KBUILD_ENABLE_EXTRA_GCC_CHECKS),)
104 cmd_checkdoc = $(srctree)/scripts/kernel-doc -none $< ;
105endif
106
107# Do section mismatch analysis for each module/built-in.a
108ifdef CONFIG_DEBUG_SECTION_MISMATCH
109 cmd_secanalysis = ; scripts/mod/modpost $@
110endif
111
112# Compile C sources (.c)
113# ---------------------------------------------------------------------------
114
115# Default is built-in, unless we know otherwise
116modkern_cflags = \
117 $(if $(part-of-module), \
118 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
119 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
120quiet_modtag := $(empty) $(empty)
121
122$(real-obj-m) : part-of-module := y
123$(real-obj-m:.o=.i) : part-of-module := y
124$(real-obj-m:.o=.s) : part-of-module := y
125$(real-obj-m:.o=.lst): part-of-module := y
126
127$(real-obj-m) : quiet_modtag := [M]
128$(real-obj-m:.o=.i) : quiet_modtag := [M]
129$(real-obj-m:.o=.s) : quiet_modtag := [M]
130$(real-obj-m:.o=.lst): quiet_modtag := [M]
131
132$(obj-m) : quiet_modtag := [M]
133
134quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
135cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
136
137$(obj)/%.s: $(src)/%.c FORCE
138 $(call if_changed_dep,cc_s_c)
139
140quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@
141cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $<
142
143$(obj)/%.i: $(src)/%.c FORCE
144 $(call if_changed_dep,cpp_i_c)
145
146# These mirror gensymtypes_S and co below, keep them in synch.
147cmd_gensymtypes_c = \
148 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
149 $(GENKSYMS) $(if $(1), -T $(2)) \
150 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
151 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
152 $(if $(KBUILD_PRESERVE),-p) \
153 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
154
155quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
156cmd_cc_symtypes_c = \
157 set -e; \
158 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \
159 test -s $@ || rm -f $@
160
161$(obj)/%.symtypes : $(src)/%.c FORCE
162 $(call cmd,cc_symtypes_c)
163
164# LLVM assembly
165# Generate .ll files from .c
166quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@
167 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $<
168
169$(obj)/%.ll: $(src)/%.c FORCE
170 $(call if_changed_dep,cc_ll_c)
171
172# C (.c) files
173# The C file is compiled and updated dependency information is generated.
174# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
175
176quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
177
178ifndef CONFIG_MODVERSIONS
179cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
180
181else
182# When module versioning is enabled the following steps are executed:
183# o compile a .tmp_<file>.o from <file>.c
184# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
185# not export symbols, we just rename .tmp_<file>.o to <file>.o and
186# are done.
187# o otherwise, we calculate symbol versions using the good old
188# genksyms on the preprocessed source and postprocess them in a way
189# that they are usable as a linker script
190# o generate <file>.o from .tmp_<file>.o using the linker to
191# replace the unresolved symbols __crc_exported_symbol with
192# the actual value of the checksum generated by genksyms
193
194cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
195
196cmd_modversions_c = \
197 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
198 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
199 > $(@D)/.tmp_$(@F:.o=.ver); \
200 \
201 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
202 -T $(@D)/.tmp_$(@F:.o=.ver); \
203 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
204 else \
205 mv -f $(@D)/.tmp_$(@F) $@; \
206 fi;
207endif
208
209ifdef CONFIG_FTRACE_MCOUNT_RECORD
210ifdef BUILD_C_RECORDMCOUNT
211ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
212 RECORDMCOUNT_FLAGS = -w
213endif
214# Due to recursion, we must skip empty.o.
215# The empty.o file is created in the make process in order to determine
216# the target endianness and word size. It is made before all other C
217# files, including recordmcount.
218sub_cmd_record_mcount = \
219 if [ $(@) != "scripts/mod/empty.o" ]; then \
220 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
221 fi;
222recordmcount_source := $(srctree)/scripts/recordmcount.c \
223 $(srctree)/scripts/recordmcount.h
224else
225sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
226 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
227 "$(if $(CONFIG_64BIT),64,32)" \
228 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
229 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
230 "$(if $(part-of-module),1,0)" "$(@)";
231recordmcount_source := $(srctree)/scripts/recordmcount.pl
232endif # BUILD_C_RECORDMCOUNT
233cmd_record_mcount = \
234 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \
235 "$(CC_FLAGS_FTRACE)" ]; then \
236 $(sub_cmd_record_mcount) \
237 fi;
238endif # CONFIG_FTRACE_MCOUNT_RECORD
239
240ifdef CONFIG_STACK_VALIDATION
241ifneq ($(SKIP_STACK_VALIDATION),1)
242
243__objtool_obj := $(objtree)/tools/objtool/objtool
244
245objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check)
246
247objtool_args += $(if $(part-of-module), --module,)
248
249ifndef CONFIG_FRAME_POINTER
250objtool_args += --no-fp
251endif
252ifdef CONFIG_GCOV_KERNEL
253objtool_args += --no-unreachable
254else
255objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable)
256endif
257ifdef CONFIG_RETPOLINE
258ifneq ($(RETPOLINE_CFLAGS),)
259 objtool_args += --retpoline
260endif
261endif
262
263
264ifdef CONFIG_MODVERSIONS
265objtool_o = $(@D)/.tmp_$(@F)
266else
267objtool_o = $(@)
268endif
269
270# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory
271# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file
272# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file
273cmd_objtool = $(if $(patsubst y%,, \
274 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
275 $(__objtool_obj) $(objtool_args) "$(objtool_o)";)
276objtool_obj = $(if $(patsubst y%,, \
277 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \
278 $(__objtool_obj))
279
280endif # SKIP_STACK_VALIDATION
281endif # CONFIG_STACK_VALIDATION
282
283# Rebuild all objects when objtool changes, or is enabled/disabled.
284objtool_dep = $(objtool_obj) \
285 $(wildcard include/config/orc/unwinder.h \
286 include/config/stack/validation.h)
287
288define rule_cc_o_c
289 $(call echo-cmd,checksrc) $(cmd_checksrc) \
290 $(call cmd_and_fixdep,cc_o_c) \
291 $(cmd_checkdoc) \
292 $(call echo-cmd,objtool) $(cmd_objtool) \
293 $(cmd_modversions_c) \
294 $(call echo-cmd,record_mcount) $(cmd_record_mcount)
295endef
296
297define rule_as_o_S
298 $(call cmd_and_fixdep,as_o_S) \
299 $(call echo-cmd,objtool) $(cmd_objtool) \
300 $(cmd_modversions_S)
301endef
302
303# List module undefined symbols (or empty line if not enabled)
304ifdef CONFIG_TRIM_UNUSED_KSYMS
305cmd_undef_syms = $(NM) $@ | sed -n 's/^ *U //p' | xargs echo
306else
307cmd_undef_syms = echo
308endif
309
310# Built-in and composite module parts
311$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
312 $(call cmd,force_checksrc)
313 $(call if_changed_rule,cc_o_c)
314
315# Single-part modules are special since we need to mark them in $(MODVERDIR)
316
317$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE
318 $(call cmd,force_checksrc)
319 $(call if_changed_rule,cc_o_c)
320 @{ echo $(@:.o=.ko); echo $@; \
321 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
322
323quiet_cmd_cc_lst_c = MKLST $@
324 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
325 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
326 System.map $(OBJDUMP) > $@
327
328$(obj)/%.lst: $(src)/%.c FORCE
329 $(call if_changed_dep,cc_lst_c)
330
331# Compile assembler sources (.S)
332# ---------------------------------------------------------------------------
333
334modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
335
336$(real-obj-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
337$(real-obj-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
338
339# .S file exports must have their C prototypes defined in asm/asm-prototypes.h
340# or a file that it includes, in order to get versioned symbols. We build a
341# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from
342# the .S file (with trailing ';'), and run genksyms on that, to extract vers.
343#
344# This is convoluted. The .S file must first be preprocessed to run guards and
345# expand names, then the resulting exports must be constructed into plain
346# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed
347# to make the genksyms input.
348#
349# These mirror gensymtypes_c and co above, keep them in synch.
350cmd_gensymtypes_S = \
351 (echo "\#include <linux/kernel.h>" ; \
352 echo "\#include <asm/asm-prototypes.h>" ; \
353 $(CPP) $(a_flags) $< | \
354 grep "\<___EXPORT_SYMBOL\>" | \
355 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \
356 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \
357 $(GENKSYMS) $(if $(1), -T $(2)) \
358 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \
359 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \
360 $(if $(KBUILD_PRESERVE),-p) \
361 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
362
363quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@
364cmd_cc_symtypes_S = \
365 set -e; \
366 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \
367 test -s $@ || rm -f $@
368
369$(obj)/%.symtypes : $(src)/%.S FORCE
370 $(call cmd,cc_symtypes_S)
371
372
373quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@
374cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $<
375
376$(obj)/%.s: $(src)/%.S FORCE
377 $(call if_changed_dep,cpp_s_S)
378
379quiet_cmd_as_o_S = AS $(quiet_modtag) $@
380
381ifndef CONFIG_MODVERSIONS
382cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
383
384else
385
386ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h)
387
388ifeq ($(ASM_PROTOTYPES),)
389cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
390
391else
392
393# versioning matches the C process described above, with difference that
394# we parse asm-prototypes.h C header to get function definitions.
395
396cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $<
397
398cmd_modversions_S = \
399 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
400 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
401 > $(@D)/.tmp_$(@F:.o=.ver); \
402 \
403 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
404 -T $(@D)/.tmp_$(@F:.o=.ver); \
405 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
406 else \
407 mv -f $(@D)/.tmp_$(@F) $@; \
408 fi;
409endif
410endif
411
412$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE
413 $(call if_changed_rule,as_o_S)
414
415targets += $(filter-out $(subdir-obj-y), $(real-obj-y)) $(real-obj-m) $(lib-y)
416targets += $(extra-y) $(MAKECMDGOALS) $(always)
417
418# Linker scripts preprocessor (.lds.S -> .lds)
419# ---------------------------------------------------------------------------
420quiet_cmd_cpp_lds_S = LDS $@
421 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
422 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
423
424$(obj)/%.lds: $(src)/%.lds.S FORCE
425 $(call if_changed_dep,cpp_lds_S)
426
427# ASN.1 grammar
428# ---------------------------------------------------------------------------
429quiet_cmd_asn1_compiler = ASN.1 $@
430 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \
431 $(subst .h,.c,$@) $(subst .c,.h,$@)
432
433$(obj)/%.asn1.c $(obj)/%.asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler
434 $(call cmd,asn1_compiler)
435
436# Build the compiled-in targets
437# ---------------------------------------------------------------------------
438
439# To build objects in subdirs, we need to descend into the directories
440$(sort $(subdir-obj-y)): $(subdir-ym) ;
441
442#
443# Rule to compile a set of .o files into one .o file
444#
445ifdef builtin-target
446
447# built-in.a archives are made with no symbol table or index which
448# makes them small and fast, but unable to be used by the linker.
449# scripts/link-vmlinux.sh builds an aggregate built-in.a with a symbol
450# table and index.
451quiet_cmd_ar_builtin = AR $@
452 cmd_ar_builtin = rm -f $@; \
453 $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(filter $(real-obj-y), $^)
454
455$(builtin-target): $(real-obj-y) FORCE
456 $(call if_changed,ar_builtin)
457
458targets += $(builtin-target)
459endif # builtin-target
460
461#
462# Rule to create modules.order file
463#
464# Create commands to either record .ko file or cat modules.order from
465# a subdirectory
466modorder-cmds = \
467 $(foreach m, $(modorder), \
468 $(if $(filter %/modules.order, $m), \
469 cat $m;, echo kernel/$m;))
470
471$(modorder-target): $(subdir-ym) FORCE
472 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
473
474#
475# Rule to compile a set of .o files into one .a file
476#
477ifdef lib-target
478quiet_cmd_link_l_target = AR $@
479
480# lib target archives do get a symbol table and index
481cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y)
482
483$(lib-target): $(lib-y) FORCE
484 $(call if_changed,link_l_target)
485
486targets += $(lib-target)
487
488dummy-object = $(obj)/.lib_exports.o
489ksyms-lds = $(dot-target).lds
490ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
491ref_prefix = EXTERN(_
492else
493ref_prefix = EXTERN(
494endif
495
496quiet_cmd_export_list = EXPORTS $@
497cmd_export_list = $(OBJDUMP) -h $< | \
498 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\
499 rm -f $(dummy-object);\
500 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\
501 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\
502 rm $(dummy-object) $(ksyms-lds)
503
504$(obj)/lib-ksyms.o: $(lib-target) FORCE
505 $(call if_changed,export_list)
506
507targets += $(obj)/lib-ksyms.o
508
509endif
510
511#
512# Rule to link composite objects
513#
514# Composite objects are specified in kbuild makefile as follows:
515# <composite-object>-objs := <list of .o files>
516# or
517# <composite-object>-y := <list of .o files>
518# or
519# <composite-object>-m := <list of .o files>
520# The -m syntax only works if <composite object> is a module
521link_multi_deps = \
522$(filter $(addprefix $(obj)/, \
523$($(subst $(obj)/,,$(@:.o=-objs))) \
524$($(subst $(obj)/,,$(@:.o=-y))) \
525$($(subst $(obj)/,,$(@:.o=-m)))), $^)
526
527quiet_cmd_link_multi-m = LD [M] $@
528cmd_link_multi-m = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
529
530$(multi-used-m): FORCE
531 $(call if_changed,link_multi-m)
532 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \
533 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod)
534$(call multi_depend, $(multi-used-m), .o, -objs -y -m)
535
536targets += $(multi-used-m)
537targets := $(filter-out $(PHONY), $(targets))
538
539# Add intermediate targets:
540# When building objects with specific suffix patterns, add intermediate
541# targets that the final targets are derived from.
542intermediate_targets = $(foreach sfx, $(2), \
543 $(patsubst %$(strip $(1)),%$(sfx), \
544 $(filter %$(strip $(1)), $(targets))))
545# %.asn1.o <- %.asn1.[ch] <- %.asn1
546# %.dtb.o <- %.dtb.S <- %.dtb <- %.dts
547# %.lex.o <- %.lex.c <- %.l
548# %.tab.o <- %.tab.[ch] <- %.y
549targets += $(call intermediate_targets, .asn1.o, .asn1.c .asn1.h) \
550 $(call intermediate_targets, .dtb.o, .dtb.S .dtb) \
551 $(call intermediate_targets, .lex.o, .lex.c) \
552 $(call intermediate_targets, .tab.o, .tab.c .tab.h)
553
554# Descending
555# ---------------------------------------------------------------------------
556
557PHONY += $(subdir-ym)
558$(subdir-ym):
559 $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1)
560
561# Add FORCE to the prequisites of a target to force it to be always rebuilt.
562# ---------------------------------------------------------------------------
563
564PHONY += FORCE
565
566FORCE:
567
568# Read all saved command lines and dependencies for the $(targets) we
569# may be building above, using $(if_changed{,_dep}). As an
570# optimization, we don't need to read them if the target does not
571# exist, we will rebuild anyway in that case.
572
573cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd))
574
575ifneq ($(cmd_files),)
576 include $(cmd_files)
577endif
578
579ifneq ($(KBUILD_SRC),)
580# Create directories for object files if they do not exist
581obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets))))
582# If cmd_files exist, their directories apparently exist. Skip mkdir.
583exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files))))
584obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs)))
585ifneq ($(obj-dirs),)
586$(shell mkdir -p $(obj-dirs))
587endif
588endif
589
590# Some files contained in $(targets) are intermediate artifacts.
591# We never want them to be removed automatically.
592.SECONDARY: $(targets)
593
594# Declare the contents of the .PHONY variable as phony. We keep that
595# information in a variable se we can use it in if_changed and friends.
596
597.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 += -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
74warning-2 := -Waggregate-return
75warning-2 += -Wcast-align
76warning-2 += -Wdisabled-optimization
77warning-2 += -Wnested-externs
78warning-2 += -Wshadow
79warning-2 += $(call cc-option, -Wlogical-op)
80warning-2 += $(call cc-option, -Wmissing-field-initializers)
81
82warning-3 := -Wbad-function-cast
83warning-3 += -Wcast-qual
84warning-3 += -Wconversion
85warning-3 += -Wpacked
86warning-3 += -Wpadded
87warning-3 += -Wpointer-arith
88warning-3 += -Wredundant-decls
89warning-3 += -Wswitch-default
90warning-3 += $(call cc-option, -Wpacked-bitfield-compat)
91warning-3 += $(call cc-option, -Wvla)
92
93warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
94warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
95warning += $(warning-$(findstring 3, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))
96
97ifeq ("$(strip $(warning))","")
98 $(error W=$(KBUILD_ENABLE_EXTRA_GCC_CHECKS) is unknown)
99endif
100
101KBUILD_CFLAGS += $(warning)
102endif
103
104include scripts/Makefile.lib
105
106ifdef host-progs
107ifneq ($(hostprogs-y),$(host-progs))
108$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
109hostprogs-y += $(host-progs)
110endif
111endif
112
113# Do not include host rules unless needed
114ifneq ($(hostprogs-y)$(hostprogs-m),)
115include scripts/Makefile.host
116endif
117
118ifneq ($(KBUILD_SRC),)
119# Create output directory if not already present
120_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
121
122# Create directories for object files if directory does not exist
123# Needed when obj-y := dir/file.o syntax is used
124_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
125endif
126
127ifndef obj
128$(warning kbuild: Makefile.build is included improperly)
129endif
130
131# ===========================================================================
132
133ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
134lib-target := $(obj)/lib.a
135endif
136
137ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(subdir-m) $(lib-target)),)
138builtin-target := $(obj)/built-in.o
139endif
140
141modorder-target := $(obj)/modules.order
142
143# We keep a list of all modules in $(MODVERDIR)
144
145__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
146 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \
147 $(subdir-ym) $(always)
148 @:
149
150# Linus' kernel sanity checking tool
151ifneq ($(KBUILD_CHECKSRC),0)
152 ifeq ($(KBUILD_CHECKSRC),2)
153 quiet_cmd_force_checksrc = CHECK $<
154 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
155 else
156 quiet_cmd_checksrc = CHECK $<
157 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
158 endif
159endif
160
161# Do section mismatch analysis for each module/built-in.o
162ifdef CONFIG_DEBUG_SECTION_MISMATCH
163 cmd_secanalysis = ; scripts/mod/modpost $@
164endif
165
166# Compile C sources (.c)
167# ---------------------------------------------------------------------------
168
169# Default is built-in, unless we know otherwise
170modkern_cflags = \
171 $(if $(part-of-module), \
172 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
173 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL))
174quiet_modtag := $(empty) $(empty)
175
176$(real-objs-m) : part-of-module := y
177$(real-objs-m:.o=.i) : part-of-module := y
178$(real-objs-m:.o=.s) : part-of-module := y
179$(real-objs-m:.o=.lst): part-of-module := y
180
181$(real-objs-m) : quiet_modtag := [M]
182$(real-objs-m:.o=.i) : quiet_modtag := [M]
183$(real-objs-m:.o=.s) : quiet_modtag := [M]
184$(real-objs-m:.o=.lst): quiet_modtag := [M]
185
186$(obj-m) : quiet_modtag := [M]
187
188# Default for not multi-part modules
189modname = $(basetarget)
190
191$(multi-objs-m) : modname = $(modname-multi)
192$(multi-objs-m:.o=.i) : modname = $(modname-multi)
193$(multi-objs-m:.o=.s) : modname = $(modname-multi)
194$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
195$(multi-objs-y) : modname = $(modname-multi)
196$(multi-objs-y:.o=.i) : modname = $(modname-multi)
197$(multi-objs-y:.o=.s) : modname = $(modname-multi)
198$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
199
200quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
201cmd_cc_s_c = $(CC) $(c_flags) -fverbose-asm -S -o $@ $<
202
203$(obj)/%.s: $(src)/%.c FORCE
204 $(call if_changed_dep,cc_s_c)
205
206quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
207cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
208
209$(obj)/%.i: $(src)/%.c FORCE
210 $(call if_changed_dep,cc_i_c)
211
212cmd_gensymtypes = \
213 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \
214 $(GENKSYMS) $(if $(1), -T $(2)) -a $(ARCH) \
215 $(if $(KBUILD_PRESERVE),-p) \
216 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null))
217
218quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@
219cmd_cc_symtypes_c = \
220 set -e; \
221 $(call cmd_gensymtypes,true,$@) >/dev/null; \
222 test -s $@ || rm -f $@
223
224$(obj)/%.symtypes : $(src)/%.c FORCE
225 $(call cmd,cc_symtypes_c)
226
227# C (.c) files
228# The C file is compiled and updated dependency information is generated.
229# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
230
231quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
232
233ifndef CONFIG_MODVERSIONS
234cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
235
236else
237# When module versioning is enabled the following steps are executed:
238# o compile a .tmp_<file>.o from <file>.c
239# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
240# not export symbols, we just rename .tmp_<file>.o to <file>.o and
241# are done.
242# o otherwise, we calculate symbol versions using the good old
243# genksyms on the preprocessed source and postprocess them in a way
244# that they are usable as a linker script
245# o generate <file>.o from .tmp_<file>.o using the linker to
246# replace the unresolved symbols __crc_exported_symbol with
247# the actual value of the checksum generated by genksyms
248
249cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
250cmd_modversions = \
251 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
252 $(call cmd_gensymtypes,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \
253 > $(@D)/.tmp_$(@F:.o=.ver); \
254 \
255 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
256 -T $(@D)/.tmp_$(@F:.o=.ver); \
257 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
258 else \
259 mv -f $(@D)/.tmp_$(@F) $@; \
260 fi;
261endif
262
263ifdef CONFIG_FTRACE_MCOUNT_RECORD
264ifdef BUILD_C_RECORDMCOUNT
265ifeq ("$(origin RECORDMCOUNT_WARN)", "command line")
266 RECORDMCOUNT_FLAGS = -w
267endif
268# Due to recursion, we must skip empty.o.
269# The empty.o file is created in the make process in order to determine
270# the target endianness and word size. It is made before all other C
271# files, including recordmcount.
272sub_cmd_record_mcount = \
273 if [ $(@) != "scripts/mod/empty.o" ]; then \
274 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \
275 fi;
276recordmcount_source := $(srctree)/scripts/recordmcount.c \
277 $(srctree)/scripts/recordmcount.h
278else
279sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \
280 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \
281 "$(if $(CONFIG_64BIT),64,32)" \
282 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \
283 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \
284 "$(if $(part-of-module),1,0)" "$(@)";
285recordmcount_source := $(srctree)/scripts/recordmcount.pl
286endif
287cmd_record_mcount = \
288 if [ "$(findstring -pg,$(_c_flags))" = "-pg" ]; then \
289 $(sub_cmd_record_mcount) \
290 fi;
291endif
292
293define rule_cc_o_c
294 $(call echo-cmd,checksrc) $(cmd_checksrc) \
295 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \
296 $(cmd_modversions) \
297 $(call echo-cmd,record_mcount) \
298 $(cmd_record_mcount) \
299 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \
300 $(dot-target).tmp; \
301 rm -f $(depfile); \
302 mv -f $(dot-target).tmp $(dot-target).cmd
303endef
304
305# Built-in and composite module parts
306$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
307 $(call cmd,force_checksrc)
308 $(call if_changed_rule,cc_o_c)
309
310# Single-part modules are special since we need to mark them in $(MODVERDIR)
311
312$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE
313 $(call cmd,force_checksrc)
314 $(call if_changed_rule,cc_o_c)
315 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
316
317quiet_cmd_cc_lst_c = MKLST $@
318 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
319 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
320 System.map $(OBJDUMP) > $@
321
322$(obj)/%.lst: $(src)/%.c FORCE
323 $(call if_changed_dep,cc_lst_c)
324
325# Compile assembler sources (.S)
326# ---------------------------------------------------------------------------
327
328modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL)
329
330$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
331$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE)
332
333quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
334cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
335
336$(obj)/%.s: $(src)/%.S FORCE
337 $(call if_changed_dep,as_s_S)
338
339quiet_cmd_as_o_S = AS $(quiet_modtag) $@
340cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
341
342$(obj)/%.o: $(src)/%.S FORCE
343 $(call if_changed_dep,as_o_S)
344
345targets += $(real-objs-y) $(real-objs-m) $(lib-y)
346targets += $(extra-y) $(MAKECMDGOALS) $(always)
347
348# Linker scripts preprocessor (.lds.S -> .lds)
349# ---------------------------------------------------------------------------
350quiet_cmd_cpp_lds_S = LDS $@
351 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \
352 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
353
354$(obj)/%.lds: $(src)/%.lds.S FORCE
355 $(call if_changed_dep,cpp_lds_S)
356
357# Build the compiled-in targets
358# ---------------------------------------------------------------------------
359
360# To build objects in subdirs, we need to descend into the directories
361$(sort $(subdir-obj-y)): $(subdir-ym) ;
362
363#
364# Rule to compile a set of .o files into one .o file
365#
366ifdef builtin-target
367quiet_cmd_link_o_target = LD $@
368# If the list of objects to link is empty, just create an empty built-in.o
369cmd_link_o_target = $(if $(strip $(obj-y)),\
370 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \
371 $(cmd_secanalysis),\
372 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@)
373
374$(builtin-target): $(obj-y) FORCE
375 $(call if_changed,link_o_target)
376
377targets += $(builtin-target)
378endif # builtin-target
379
380#
381# Rule to create modules.order file
382#
383# Create commands to either record .ko file or cat modules.order from
384# a subdirectory
385modorder-cmds = \
386 $(foreach m, $(modorder), \
387 $(if $(filter %/modules.order, $m), \
388 cat $m;, echo kernel/$m;))
389
390$(modorder-target): $(subdir-ym) FORCE
391 $(Q)(cat /dev/null; $(modorder-cmds)) > $@
392
393#
394# Rule to compile a set of .o files into one .a file
395#
396ifdef lib-target
397quiet_cmd_link_l_target = AR $@
398cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y)
399
400$(lib-target): $(lib-y) FORCE
401 $(call if_changed,link_l_target)
402
403targets += $(lib-target)
404endif
405
406#
407# Rule to link composite objects
408#
409# Composite objects are specified in kbuild makefile as follows:
410# <composite-object>-objs := <list of .o files>
411# or
412# <composite-object>-y := <list of .o files>
413link_multi_deps = \
414$(filter $(addprefix $(obj)/, \
415$($(subst $(obj)/,,$(@:.o=-objs))) \
416$($(subst $(obj)/,,$(@:.o=-y)))), $^)
417
418quiet_cmd_link_multi-y = LD $@
419cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis)
420
421quiet_cmd_link_multi-m = LD [M] $@
422cmd_link_multi-m = $(cmd_link_multi-y)
423
424# We would rather have a list of rules like
425# foo.o: $(foo-objs)
426# but that's not so easy, so we rather make all composite objects depend
427# on the set of all their parts
428$(multi-used-y) : %.o: $(multi-objs-y) FORCE
429 $(call if_changed,link_multi-y)
430
431$(multi-used-m) : %.o: $(multi-objs-m) FORCE
432 $(call if_changed,link_multi-m)
433 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
434
435targets += $(multi-used-y) $(multi-used-m)
436
437
438# Descending
439# ---------------------------------------------------------------------------
440
441PHONY += $(subdir-ym)
442$(subdir-ym):
443 $(Q)$(MAKE) $(build)=$@
444
445# Add FORCE to the prequisites of a target to force it to be always rebuilt.
446# ---------------------------------------------------------------------------
447
448PHONY += FORCE
449
450FORCE:
451
452# Read all saved command lines and dependencies for the $(targets) we
453# may be building above, using $(if_changed{,_dep}). As an
454# optimization, we don't need to read them if the target does not
455# exist, we will rebuild anyway in that case.
456
457targets := $(wildcard $(sort $(targets)))
458cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
459
460ifneq ($(cmd_files),)
461 include $(cmd_files)
462endif
463
464# Declare the contents of the .PHONY variable as phony. We keep that
465# information in a variable se we can use it in if_changed and friends.
466
467.PHONY: $(PHONY)