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 76obj-y += $(obj)/lib-ksyms.o 77endif 78 79ifneq ($(strip $(obj-y) $(need-builtin)),) 80builtin-target := $(obj)/built-in.o 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 102 103# Do section mismatch analysis for each module/built-in.o 104ifdef CONFIG_DEBUG_SECTION_MISMATCH 105 cmd_secanalysis = ; scripts/mod/modpost $@ 106endif 107 108# Compile C sources (.c) 109# --------------------------------------------------------------------------- 110 111# Default is built-in, unless we know otherwise 112modkern_cflags = \ 113 $(if $(part-of-module), \ 114 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 115 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL)) 116quiet_modtag := $(empty) $(empty) 117 118$(real-objs-m) : part-of-module := y 119$(real-objs-m:.o=.i) : part-of-module := y 120$(real-objs-m:.o=.s) : part-of-module := y 121$(real-objs-m:.o=.lst): part-of-module := y 122 123$(real-objs-m) : quiet_modtag := [M] 124$(real-objs-m:.o=.i) : quiet_modtag := [M] 125$(real-objs-m:.o=.s) : quiet_modtag := [M] 126$(real-objs-m:.o=.lst): quiet_modtag := [M] 127 128$(obj-m) : quiet_modtag := [M] 129 130# Default for not multi-part modules 131modname = $(basetarget) 132 133$(multi-objs-m) : modname = $(modname-multi) 134$(multi-objs-m:.o=.i) : modname = $(modname-multi) 135$(multi-objs-m:.o=.s) : modname = $(modname-multi) 136$(multi-objs-m:.o=.lst) : modname = $(modname-multi) 137$(multi-objs-y) : modname = $(modname-multi) 138$(multi-objs-y:.o=.i) : modname = $(modname-multi) 139$(multi-objs-y:.o=.s) : modname = $(modname-multi) 140$(multi-objs-y:.o=.lst) : modname = $(modname-multi) 141 142quiet_cmd_cc_s_c = CC $(quiet_modtag) $@ 143cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $< 144 145$(obj)/%.s: $(src)/%.c FORCE 146 $(call if_changed_dep,cc_s_c) 147 148quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@ 149cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $< 150 151$(obj)/%.i: $(src)/%.c FORCE 152 $(call if_changed_dep,cpp_i_c) 153 154# These mirror gensymtypes_S and co below, keep them in synch. 155cmd_gensymtypes_c = \ 156 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ 157 $(GENKSYMS) $(if $(1), -T $(2)) \ 158 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 159 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \ 160 $(if $(KBUILD_PRESERVE),-p) \ 161 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 162 163quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ 164cmd_cc_symtypes_c = \ 165 set -e; \ 166 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \ 167 test -s $@ || rm -f $@ 168 169$(obj)/%.symtypes : $(src)/%.c FORCE 170 $(call cmd,cc_symtypes_c) 171 172# LLVM assembly 173# Generate .ll files from .c 174quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@ 175 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $< 176 177$(obj)/%.ll: $(src)/%.c FORCE 178 $(call if_changed_dep,cc_ll_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 := $(srctree)/scripts/recordmcount.pl 240endif # BUILD_C_RECORDMCOUNT 241cmd_record_mcount = \ 242 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \ 243 "$(CC_FLAGS_FTRACE)" ]; then \ 244 $(sub_cmd_record_mcount) \ 245 fi; 246endif # CONFIG_FTRACE_MCOUNT_RECORD 247 248ifdef CONFIG_STACK_VALIDATION 249ifneq ($(SKIP_STACK_VALIDATION),1) 250 251__objtool_obj := $(objtree)/tools/objtool/objtool 252 253objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check) 254 255ifndef CONFIG_FRAME_POINTER 256objtool_args += --no-fp 257endif 258ifdef CONFIG_GCOV_KERNEL 259objtool_args += --no-unreachable 260else 261objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable) 262endif 263 264# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory 265# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file 266# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file 267cmd_objtool = $(if $(patsubst y%,, \ 268 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 269 $(__objtool_obj) $(objtool_args) "$(@)";) 270objtool_obj = $(if $(patsubst y%,, \ 271 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 272 $(__objtool_obj)) 273 274endif # SKIP_STACK_VALIDATION 275endif # CONFIG_STACK_VALIDATION 276 277# Rebuild all objects when objtool changes, or is enabled/disabled. 278objtool_dep = $(objtool_obj) \ 279 $(wildcard include/config/orc/unwinder.h \ 280 include/config/stack/validation.h) 281 282define rule_cc_o_c 283 $(call echo-cmd,checksrc) $(cmd_checksrc) \ 284 $(call cmd_and_fixdep,cc_o_c) \ 285 $(cmd_modversions_c) \ 286 $(call echo-cmd,objtool) $(cmd_objtool) \ 287 $(call echo-cmd,record_mcount) $(cmd_record_mcount) 288endef 289 290define rule_as_o_S 291 $(call cmd_and_fixdep,as_o_S) \ 292 $(cmd_modversions_S) \ 293 $(call echo-cmd,objtool) $(cmd_objtool) 294endef 295 296# List module undefined symbols (or empty line if not enabled) 297ifdef CONFIG_TRIM_UNUSED_KSYMS 298cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo 299else 300cmd_undef_syms = echo 301endif 302 303# Built-in and composite module parts 304$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE 305 $(call cmd,force_checksrc) 306 $(call if_changed_rule,cc_o_c) 307 308# Single-part modules are special since we need to mark them in $(MODVERDIR) 309 310$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE 311 $(call cmd,force_checksrc) 312 $(call if_changed_rule,cc_o_c) 313 @{ echo $(@:.o=.ko); echo $@; \ 314 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 315 316quiet_cmd_cc_lst_c = MKLST $@ 317 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \ 318 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \ 319 System.map $(OBJDUMP) > $@ 320 321$(obj)/%.lst: $(src)/%.c FORCE 322 $(call if_changed_dep,cc_lst_c) 323 324# Compile assembler sources (.S) 325# --------------------------------------------------------------------------- 326 327modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) 328 329$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 330$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 331 332# .S file exports must have their C prototypes defined in asm/asm-prototypes.h 333# or a file that it includes, in order to get versioned symbols. We build a 334# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from 335# the .S file (with trailing ';'), and run genksyms on that, to extract vers. 336# 337# This is convoluted. The .S file must first be preprocessed to run guards and 338# expand names, then the resulting exports must be constructed into plain 339# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed 340# to make the genksyms input. 341# 342# These mirror gensymtypes_c and co above, keep them in synch. 343cmd_gensymtypes_S = \ 344 (echo "\#include <linux/kernel.h>" ; \ 345 echo "\#include <asm/asm-prototypes.h>" ; \ 346 $(CPP) $(a_flags) $< | \ 347 grep "\<___EXPORT_SYMBOL\>" | \ 348 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \ 349 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ 350 $(GENKSYMS) $(if $(1), -T $(2)) \ 351 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 352 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \ 353 $(if $(KBUILD_PRESERVE),-p) \ 354 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 355 356quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@ 357cmd_cc_symtypes_S = \ 358 set -e; \ 359 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \ 360 test -s $@ || rm -f $@ 361 362$(obj)/%.symtypes : $(src)/%.S FORCE 363 $(call cmd,cc_symtypes_S) 364 365 366quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@ 367cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $< 368 369$(obj)/%.s: $(src)/%.S FORCE 370 $(call if_changed_dep,cpp_s_S) 371 372quiet_cmd_as_o_S = AS $(quiet_modtag) $@ 373 374ifndef CONFIG_MODVERSIONS 375cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 376 377else 378 379ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h) 380 381ifeq ($(ASM_PROTOTYPES),) 382cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 383 384else 385 386# versioning matches the C process described above, with difference that 387# we parse asm-prototypes.h C header to get function definitions. 388 389cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $< 390 391cmd_modversions_S = \ 392 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 393 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 394 > $(@D)/.tmp_$(@F:.o=.ver); \ 395 \ 396 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 397 -T $(@D)/.tmp_$(@F:.o=.ver); \ 398 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 399 else \ 400 mv -f $(@D)/.tmp_$(@F) $@; \ 401 fi; 402endif 403endif 404 405$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE 406 $(call if_changed_rule,as_o_S) 407 408targets += $(real-objs-y) $(real-objs-m) $(lib-y) 409targets += $(extra-y) $(MAKECMDGOALS) $(always) 410 411# Linker scripts preprocessor (.lds.S -> .lds) 412# --------------------------------------------------------------------------- 413quiet_cmd_cpp_lds_S = LDS $@ 414 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \ 415 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $< 416 417$(obj)/%.lds: $(src)/%.lds.S FORCE 418 $(call if_changed_dep,cpp_lds_S) 419 420# ASN.1 grammar 421# --------------------------------------------------------------------------- 422quiet_cmd_asn1_compiler = ASN.1 $@ 423 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \ 424 $(subst .h,.c,$@) $(subst .c,.h,$@) 425 426.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h 427 428$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler 429 $(call cmd,asn1_compiler) 430 431# Build the compiled-in targets 432# --------------------------------------------------------------------------- 433 434# To build objects in subdirs, we need to descend into the directories 435$(sort $(subdir-obj-y)): $(subdir-ym) ; 436 437# 438# Rule to compile a set of .o files into one .o file 439# 440ifdef builtin-target 441 442ifdef CONFIG_THIN_ARCHIVES 443 cmd_make_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) 444 cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) 445 quiet_cmd_link_o_target = AR $@ 446else 447 cmd_make_builtin = $(LD) $(ld_flags) -r -o 448 cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) 449 quiet_cmd_link_o_target = LD $@ 450endif 451 452# If the list of objects to link is empty, just create an empty built-in.o 453cmd_link_o_target = $(if $(strip $(obj-y)),\ 454 $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \ 455 $(cmd_secanalysis),\ 456 $(cmd_make_empty_builtin) $@) 457 458$(builtin-target): $(obj-y) FORCE 459 $(call if_changed,link_o_target) 460 461targets += $(builtin-target) 462endif # builtin-target 463 464# 465# Rule to create modules.order file 466# 467# Create commands to either record .ko file or cat modules.order from 468# a subdirectory 469modorder-cmds = \ 470 $(foreach m, $(modorder), \ 471 $(if $(filter %/modules.order, $m), \ 472 cat $m;, echo kernel/$m;)) 473 474$(modorder-target): $(subdir-ym) FORCE 475 $(Q)(cat /dev/null; $(modorder-cmds)) > $@ 476 477# 478# Rule to compile a set of .o files into one .a file 479# 480ifdef lib-target 481quiet_cmd_link_l_target = AR $@ 482 483ifdef CONFIG_THIN_ARCHIVES 484 cmd_link_l_target = rm -f $@; $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y) 485else 486 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y) 487endif 488 489$(lib-target): $(lib-y) FORCE 490 $(call if_changed,link_l_target) 491 492targets += $(lib-target) 493 494dummy-object = $(obj)/.lib_exports.o 495ksyms-lds = $(dot-target).lds 496ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX 497ref_prefix = EXTERN(_ 498else 499ref_prefix = EXTERN( 500endif 501 502quiet_cmd_export_list = EXPORTS $@ 503cmd_export_list = $(OBJDUMP) -h $< | \ 504 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\ 505 rm -f $(dummy-object);\ 506 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\ 507 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\ 508 rm $(dummy-object) $(ksyms-lds) 509 510$(obj)/lib-ksyms.o: $(lib-target) FORCE 511 $(call if_changed,export_list) 512 513targets += $(obj)/lib-ksyms.o 514 515endif 516 517# 518# Rule to link composite objects 519# 520# Composite objects are specified in kbuild makefile as follows: 521# <composite-object>-objs := <list of .o files> 522# or 523# <composite-object>-y := <list of .o files> 524# or 525# <composite-object>-m := <list of .o files> 526# The -m syntax only works if <composite object> is a module 527link_multi_deps = \ 528$(filter $(addprefix $(obj)/, \ 529$($(subst $(obj)/,,$(@:.o=-objs))) \ 530$($(subst $(obj)/,,$(@:.o=-y))) \ 531$($(subst $(obj)/,,$(@:.o=-m)))), $^) 532 533cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis) 534 535ifdef CONFIG_THIN_ARCHIVES 536 quiet_cmd_link_multi-y = AR $@ 537 cmd_link_multi-y = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps) 538else 539 quiet_cmd_link_multi-y = LD $@ 540 cmd_link_multi-y = $(cmd_link_multi-link) 541endif 542 543quiet_cmd_link_multi-m = LD [M] $@ 544cmd_link_multi-m = $(cmd_link_multi-link) 545 546$(multi-used-y): FORCE 547 $(call if_changed,link_multi-y) 548$(call multi_depend, $(multi-used-y), .o, -objs -y) 549 550$(multi-used-m): FORCE 551 $(call if_changed,link_multi-m) 552 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \ 553 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 554$(call multi_depend, $(multi-used-m), .o, -objs -y -m) 555 556targets += $(multi-used-y) $(multi-used-m) 557targets := $(filter-out $(PHONY), $(targets)) 558 559# Descending 560# --------------------------------------------------------------------------- 561 562PHONY += $(subdir-ym) 563$(subdir-ym): 564 $(Q)$(MAKE) $(build)=$@ need-builtin=$(if $(findstring $@,$(subdir-obj-y)),1) 565 566# Add FORCE to the prequisites of a target to force it to be always rebuilt. 567# --------------------------------------------------------------------------- 568 569PHONY += FORCE 570 571FORCE: 572 573# Read all saved command lines and dependencies for the $(targets) we 574# may be building above, using $(if_changed{,_dep}). As an 575# optimization, we don't need to read them if the target does not 576# exist, we will rebuild anyway in that case. 577 578cmd_files := $(wildcard $(foreach f,$(sort $(targets)),$(dir $(f)).$(notdir $(f)).cmd)) 579 580ifneq ($(cmd_files),) 581 include $(cmd_files) 582endif 583 584ifneq ($(KBUILD_SRC),) 585# Create directories for object files if they do not exist 586obj-dirs := $(sort $(obj) $(patsubst %/,%, $(dir $(targets)))) 587# If cmd_files exist, their directories apparently exist. Skip mkdir. 588exist-dirs := $(sort $(patsubst %/,%, $(dir $(cmd_files)))) 589obj-dirs := $(strip $(filter-out $(exist-dirs), $(obj-dirs))) 590ifneq ($(obj-dirs),) 591$(shell mkdir -p $(obj-dirs)) 592endif 593endif 594 595# Declare the contents of the .PHONY variable as phony. We keep that 596# information in a variable se we can use it in if_changed and friends. 597 598.PHONY: $(PHONY) 599