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# LLVM assembly 181# Generate .ll files from .c 182quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@ 183 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $< 184 185$(obj)/%.ll: $(src)/%.c FORCE 186 $(call if_changed_dep,cc_ll_c) 187 188# C (.c) files 189# The C file is compiled and updated dependency information is generated. 190# (See cmd_cc_o_c + relevant part of rule_cc_o_c) 191 192quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ 193 194ifndef CONFIG_MODVERSIONS 195cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 196 197else 198# When module versioning is enabled the following steps are executed: 199# o compile a .tmp_<file>.o from <file>.c 200# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does 201# not export symbols, we just rename .tmp_<file>.o to <file>.o and 202# are done. 203# o otherwise, we calculate symbol versions using the good old 204# genksyms on the preprocessed source and postprocess them in a way 205# that they are usable as a linker script 206# o generate <file>.o from .tmp_<file>.o using the linker to 207# replace the unresolved symbols __crc_exported_symbol with 208# the actual value of the checksum generated by genksyms 209 210cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $< 211 212cmd_modversions_c = \ 213 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 214 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 215 > $(@D)/.tmp_$(@F:.o=.ver); \ 216 \ 217 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 218 -T $(@D)/.tmp_$(@F:.o=.ver); \ 219 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 220 else \ 221 mv -f $(@D)/.tmp_$(@F) $@; \ 222 fi; 223endif 224 225ifdef CONFIG_FTRACE_MCOUNT_RECORD 226ifdef BUILD_C_RECORDMCOUNT 227ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") 228 RECORDMCOUNT_FLAGS = -w 229endif 230# Due to recursion, we must skip empty.o. 231# The empty.o file is created in the make process in order to determine 232# the target endianness and word size. It is made before all other C 233# files, including recordmcount. 234sub_cmd_record_mcount = \ 235 if [ $(@) != "scripts/mod/empty.o" ]; then \ 236 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \ 237 fi; 238recordmcount_source := $(srctree)/scripts/recordmcount.c \ 239 $(srctree)/scripts/recordmcount.h 240else 241sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \ 242 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \ 243 "$(if $(CONFIG_64BIT),64,32)" \ 244 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \ 245 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \ 246 "$(if $(part-of-module),1,0)" "$(@)"; 247recordmcount_source := $(srctree)/scripts/recordmcount.pl 248endif 249cmd_record_mcount = \ 250 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \ 251 "$(CC_FLAGS_FTRACE)" ]; then \ 252 $(sub_cmd_record_mcount) \ 253 fi; 254endif 255 256ifdef CONFIG_STACK_VALIDATION 257ifneq ($(SKIP_STACK_VALIDATION),1) 258 259__objtool_obj := $(objtree)/tools/objtool/objtool 260 261objtool_args = check 262ifndef CONFIG_FRAME_POINTER 263objtool_args += --no-fp 264endif 265 266# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory 267# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file 268# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file 269cmd_objtool = $(if $(patsubst y%,, \ 270 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 271 $(__objtool_obj) $(objtool_args) "$(@)";) 272objtool_obj = $(if $(patsubst y%,, \ 273 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 274 $(__objtool_obj)) 275 276endif # SKIP_STACK_VALIDATION 277endif # CONFIG_STACK_VALIDATION 278 279define rule_cc_o_c 280 $(call echo-cmd,checksrc) $(cmd_checksrc) \ 281 $(call cmd_and_fixdep,cc_o_c) \ 282 $(cmd_modversions_c) \ 283 $(call echo-cmd,objtool) $(cmd_objtool) \ 284 $(call echo-cmd,record_mcount) $(cmd_record_mcount) 285endef 286 287define rule_as_o_S 288 $(call cmd_and_fixdep,as_o_S) \ 289 $(cmd_modversions_S) \ 290 $(call echo-cmd,objtool) $(cmd_objtool) 291endef 292 293# List module undefined symbols (or empty line if not enabled) 294ifdef CONFIG_TRIM_UNUSED_KSYMS 295cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo 296else 297cmd_undef_syms = echo 298endif 299 300# Built-in and composite module parts 301$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE 302 $(call cmd,force_checksrc) 303 $(call if_changed_rule,cc_o_c) 304 305# Single-part modules are special since we need to mark them in $(MODVERDIR) 306 307$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_obj) FORCE 308 $(call cmd,force_checksrc) 309 $(call if_changed_rule,cc_o_c) 310 @{ echo $(@:.o=.ko); echo $@; \ 311 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 312 313quiet_cmd_cc_lst_c = MKLST $@ 314 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \ 315 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \ 316 System.map $(OBJDUMP) > $@ 317 318$(obj)/%.lst: $(src)/%.c FORCE 319 $(call if_changed_dep,cc_lst_c) 320 321# Compile assembler sources (.S) 322# --------------------------------------------------------------------------- 323 324modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) 325 326$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 327$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 328 329# .S file exports must have their C prototypes defined in asm/asm-prototypes.h 330# or a file that it includes, in order to get versioned symbols. We build a 331# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from 332# the .S file (with trailing ';'), and run genksyms on that, to extract vers. 333# 334# This is convoluted. The .S file must first be preprocessed to run guards and 335# expand names, then the resulting exports must be constructed into plain 336# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed 337# to make the genksyms input. 338# 339# These mirror gensymtypes_c and co above, keep them in synch. 340cmd_gensymtypes_S = \ 341 (echo "\#include <linux/kernel.h>" ; \ 342 echo "\#include <asm/asm-prototypes.h>" ; \ 343 $(CPP) $(a_flags) $< | \ 344 grep "\<___EXPORT_SYMBOL\>" | \ 345 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \ 346 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ 347 $(GENKSYMS) $(if $(1), -T $(2)) \ 348 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 349 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \ 350 $(if $(KBUILD_PRESERVE),-p) \ 351 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 352 353quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@ 354cmd_cc_symtypes_S = \ 355 set -e; \ 356 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \ 357 test -s $@ || rm -f $@ 358 359$(obj)/%.symtypes : $(src)/%.S FORCE 360 $(call cmd,cc_symtypes_S) 361 362 363quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@ 364cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $< 365 366$(obj)/%.s: $(src)/%.S FORCE 367 $(call if_changed_dep,cpp_s_S) 368 369quiet_cmd_as_o_S = AS $(quiet_modtag) $@ 370 371ifndef CONFIG_MODVERSIONS 372cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 373 374else 375 376ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h) 377 378ifeq ($(ASM_PROTOTYPES),) 379cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 380 381else 382 383# versioning matches the C process described above, with difference that 384# we parse asm-prototypes.h C header to get function definitions. 385 386cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $< 387 388cmd_modversions_S = \ 389 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 390 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 391 > $(@D)/.tmp_$(@F:.o=.ver); \ 392 \ 393 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 394 -T $(@D)/.tmp_$(@F:.o=.ver); \ 395 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 396 else \ 397 mv -f $(@D)/.tmp_$(@F) $@; \ 398 fi; 399endif 400endif 401 402$(obj)/%.o: $(src)/%.S $(objtool_obj) FORCE 403 $(call if_changed_rule,as_o_S) 404 405targets += $(real-objs-y) $(real-objs-m) $(lib-y) 406targets += $(extra-y) $(MAKECMDGOALS) $(always) 407 408# Linker scripts preprocessor (.lds.S -> .lds) 409# --------------------------------------------------------------------------- 410quiet_cmd_cpp_lds_S = LDS $@ 411 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \ 412 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $< 413 414$(obj)/%.lds: $(src)/%.lds.S FORCE 415 $(call if_changed_dep,cpp_lds_S) 416 417# ASN.1 grammar 418# --------------------------------------------------------------------------- 419quiet_cmd_asn1_compiler = ASN.1 $@ 420 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \ 421 $(subst .h,.c,$@) $(subst .c,.h,$@) 422 423.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h 424 425$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler 426 $(call cmd,asn1_compiler) 427 428# Build the compiled-in targets 429# --------------------------------------------------------------------------- 430 431# To build objects in subdirs, we need to descend into the directories 432$(sort $(subdir-obj-y)): $(subdir-ym) ; 433 434# 435# Rule to compile a set of .o files into one .o file 436# 437ifdef builtin-target 438 439ifdef CONFIG_THIN_ARCHIVES 440 cmd_make_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) 441 cmd_make_empty_builtin = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) 442 quiet_cmd_link_o_target = AR $@ 443else 444 cmd_make_builtin = $(LD) $(ld_flags) -r -o 445 cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) 446 quiet_cmd_link_o_target = LD $@ 447endif 448 449# If the list of objects to link is empty, just create an empty built-in.o 450cmd_link_o_target = $(if $(strip $(obj-y)),\ 451 $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \ 452 $(cmd_secanalysis),\ 453 $(cmd_make_empty_builtin) $@) 454 455$(builtin-target): $(obj-y) FORCE 456 $(call if_changed,link_o_target) 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 480ifdef CONFIG_THIN_ARCHIVES 481 cmd_link_l_target = rm -f $@; $(AR) rcsT$(KBUILD_ARFLAGS) $@ $(lib-y) 482else 483 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y) 484endif 485 486$(lib-target): $(lib-y) FORCE 487 $(call if_changed,link_l_target) 488 489targets += $(lib-target) 490 491dummy-object = $(obj)/.lib_exports.o 492ksyms-lds = $(dot-target).lds 493ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX 494ref_prefix = EXTERN(_ 495else 496ref_prefix = EXTERN( 497endif 498 499quiet_cmd_export_list = EXPORTS $@ 500cmd_export_list = $(OBJDUMP) -h $< | \ 501 sed -ne '/___ksymtab/s/.*+\([^ ]*\).*/$(ref_prefix)\1)/p' >$(ksyms-lds);\ 502 rm -f $(dummy-object);\ 503 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\ 504 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\ 505 rm $(dummy-object) $(ksyms-lds) 506 507$(obj)/lib-ksyms.o: $(lib-target) FORCE 508 $(call if_changed,export_list) 509 510targets += $(obj)/lib-ksyms.o 511 512endif 513 514# 515# Rule to link composite objects 516# 517# Composite objects are specified in kbuild makefile as follows: 518# <composite-object>-objs := <list of .o files> 519# or 520# <composite-object>-y := <list of .o files> 521# or 522# <composite-object>-m := <list of .o files> 523# The -m syntax only works if <composite object> is a module 524link_multi_deps = \ 525$(filter $(addprefix $(obj)/, \ 526$($(subst $(obj)/,,$(@:.o=-objs))) \ 527$($(subst $(obj)/,,$(@:.o=-y))) \ 528$($(subst $(obj)/,,$(@:.o=-m)))), $^) 529 530cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis) 531 532ifdef CONFIG_THIN_ARCHIVES 533 quiet_cmd_link_multi-y = AR $@ 534 cmd_link_multi-y = rm -f $@; $(AR) rcST$(KBUILD_ARFLAGS) $@ $(link_multi_deps) 535else 536 quiet_cmd_link_multi-y = LD $@ 537 cmd_link_multi-y = $(cmd_link_multi-link) 538endif 539 540quiet_cmd_link_multi-m = LD [M] $@ 541cmd_link_multi-m = $(cmd_link_multi-link) 542 543$(multi-used-y): FORCE 544 $(call if_changed,link_multi-y) 545$(call multi_depend, $(multi-used-y), .o, -objs -y) 546 547$(multi-used-m): FORCE 548 $(call if_changed,link_multi-m) 549 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \ 550 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 551$(call multi_depend, $(multi-used-m), .o, -objs -y -m) 552 553targets += $(multi-used-y) $(multi-used-m) 554 555 556# Descending 557# --------------------------------------------------------------------------- 558 559PHONY += $(subdir-ym) 560$(subdir-ym): 561 $(Q)$(MAKE) $(build)=$@ 562 563# Add FORCE to the prequisites of a target to force it to be always rebuilt. 564# --------------------------------------------------------------------------- 565 566PHONY += FORCE 567 568FORCE: 569 570# Read all saved command lines and dependencies for the $(targets) we 571# may be building above, using $(if_changed{,_dep}). As an 572# optimization, we don't need to read them if the target does not 573# exist, we will rebuild anyway in that case. 574 575targets := $(wildcard $(sort $(targets))) 576cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 577 578ifneq ($(cmd_files),) 579 include $(cmd_files) 580endif 581 582# Declare the contents of the .PHONY variable as phony. We keep that 583# information in a variable se we can use it in if_changed and friends. 584 585.PHONY: $(PHONY) 586