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)$(hostcxxlibs-m),) 65include scripts/Makefile.host 66endif 67 68ifneq ($(KBUILD_SRC),) 69# Create output directory if not already present 70_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj)) 71 72# Create directories for object files if directory does not exist 73# Needed when obj-y := dir/file.o syntax is used 74_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d))) 75endif 76 77ifndef obj 78$(warning kbuild: Makefile.build is included improperly) 79endif 80 81# =========================================================================== 82 83ifneq ($(strip $(lib-y) $(lib-m) $(lib-)),) 84lib-target := $(obj)/lib.a 85obj-y += $(obj)/lib-ksyms.o 86endif 87 88ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),) 89builtin-target := $(obj)/built-in.o 90endif 91 92modorder-target := $(obj)/modules.order 93 94# We keep a list of all modules in $(MODVERDIR) 95 96__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \ 97 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \ 98 $(subdir-ym) $(always) 99 @: 100 101# Linus' kernel sanity checking tool 102ifneq ($(KBUILD_CHECKSRC),0) 103 ifeq ($(KBUILD_CHECKSRC),2) 104 quiet_cmd_force_checksrc = CHECK $< 105 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 106 else 107 quiet_cmd_checksrc = CHECK $< 108 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 109 endif 110endif 111 112# Do section mismatch analysis for each module/built-in.o 113ifdef CONFIG_DEBUG_SECTION_MISMATCH 114 cmd_secanalysis = ; scripts/mod/modpost $@ 115endif 116 117# Compile C sources (.c) 118# --------------------------------------------------------------------------- 119 120# Default is built-in, unless we know otherwise 121modkern_cflags = \ 122 $(if $(part-of-module), \ 123 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 124 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL)) 125quiet_modtag := $(empty) $(empty) 126 127$(real-objs-m) : part-of-module := y 128$(real-objs-m:.o=.i) : part-of-module := y 129$(real-objs-m:.o=.s) : part-of-module := y 130$(real-objs-m:.o=.lst): part-of-module := y 131 132$(real-objs-m) : quiet_modtag := [M] 133$(real-objs-m:.o=.i) : quiet_modtag := [M] 134$(real-objs-m:.o=.s) : quiet_modtag := [M] 135$(real-objs-m:.o=.lst): quiet_modtag := [M] 136 137$(obj-m) : quiet_modtag := [M] 138 139# Default for not multi-part modules 140modname = $(basetarget) 141 142$(multi-objs-m) : modname = $(modname-multi) 143$(multi-objs-m:.o=.i) : modname = $(modname-multi) 144$(multi-objs-m:.o=.s) : modname = $(modname-multi) 145$(multi-objs-m:.o=.lst) : modname = $(modname-multi) 146$(multi-objs-y) : modname = $(modname-multi) 147$(multi-objs-y:.o=.i) : modname = $(modname-multi) 148$(multi-objs-y:.o=.s) : modname = $(modname-multi) 149$(multi-objs-y:.o=.lst) : modname = $(modname-multi) 150 151quiet_cmd_cc_s_c = CC $(quiet_modtag) $@ 152cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $< 153 154$(obj)/%.s: $(src)/%.c FORCE 155 $(call if_changed_dep,cc_s_c) 156 157quiet_cmd_cpp_i_c = CPP $(quiet_modtag) $@ 158cmd_cpp_i_c = $(CPP) $(c_flags) -o $@ $< 159 160$(obj)/%.i: $(src)/%.c FORCE 161 $(call if_changed_dep,cpp_i_c) 162 163# These mirror gensymtypes_S and co below, keep them in synch. 164cmd_gensymtypes_c = \ 165 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ 166 $(GENKSYMS) $(if $(1), -T $(2)) \ 167 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 168 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \ 169 $(if $(KBUILD_PRESERVE),-p) \ 170 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 171 172quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ 173cmd_cc_symtypes_c = \ 174 set -e; \ 175 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \ 176 test -s $@ || rm -f $@ 177 178$(obj)/%.symtypes : $(src)/%.c FORCE 179 $(call cmd,cc_symtypes_c) 180 181# LLVM assembly 182# Generate .ll files from .c 183quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@ 184 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $< 185 186$(obj)/%.ll: $(src)/%.c FORCE 187 $(call if_changed_dep,cc_ll_c) 188 189# C (.c) files 190# The C file is compiled and updated dependency information is generated. 191# (See cmd_cc_o_c + relevant part of rule_cc_o_c) 192 193quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ 194 195ifndef CONFIG_MODVERSIONS 196cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 197 198else 199# When module versioning is enabled the following steps are executed: 200# o compile a .tmp_<file>.o from <file>.c 201# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does 202# not export symbols, we just rename .tmp_<file>.o to <file>.o and 203# are done. 204# o otherwise, we calculate symbol versions using the good old 205# genksyms on the preprocessed source and postprocess them in a way 206# that they are usable as a linker script 207# o generate <file>.o from .tmp_<file>.o using the linker to 208# replace the unresolved symbols __crc_exported_symbol with 209# the actual value of the checksum generated by genksyms 210 211cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $< 212 213ifdef CONFIG_LTO_CLANG 214# Generate .o.symversions files for each .o with exported symbols, and link these 215# to the kernel and/or modules at the end. 216cmd_modversions_c = \ 217 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) >/dev/null 2>/dev/null; then \ 218 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 219 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 220 > $(@D)/$(@F).symversions; \ 221 fi; \ 222 else \ 223 if $(LLVM_DIS) -o=- $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 224 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 225 > $(@D)/$(@F).symversions; \ 226 fi; \ 227 fi; \ 228 mv -f $(@D)/.tmp_$(@F) $@; 229else 230cmd_modversions_c = \ 231 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 232 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 233 > $(@D)/.tmp_$(@F:.o=.ver); \ 234 \ 235 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 236 -T $(@D)/.tmp_$(@F:.o=.ver); \ 237 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 238 else \ 239 mv -f $(@D)/.tmp_$(@F) $@; \ 240 fi; 241endif 242endif 243 244ifdef CONFIG_FTRACE_MCOUNT_RECORD 245ifdef BUILD_C_RECORDMCOUNT 246ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") 247 RECORDMCOUNT_FLAGS = -w 248endif 249 250ifdef CONFIG_LTO_CLANG 251# With LTO, we postpone running recordmcount until after the LTO link step, so 252# let's export the parameters for the link script. 253export RECORDMCOUNT_FLAGS 254else 255# Due to recursion, we must skip empty.o. 256# The empty.o file is created in the make process in order to determine 257# the target endianness and word size. It is made before all other C 258# files, including recordmcount. 259sub_cmd_record_mcount = \ 260 if [ $(@) != "scripts/mod/empty.o" ]; then \ 261 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \ 262 fi; 263endif 264 265recordmcount_source := $(srctree)/scripts/recordmcount.c \ 266 $(srctree)/scripts/recordmcount.h 267else # !BUILD_C_RECORDMCOUNT 268sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \ 269 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \ 270 "$(if $(CONFIG_64BIT),64,32)" \ 271 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)" \ 272 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \ 273 "$(if $(part-of-module),1,0)" "$(@)"; 274 275recordmcount_source := $(srctree)/scripts/recordmcount.pl 276endif # BUILD_C_RECORDMCOUNT 277 278ifndef CONFIG_LTO_CLANG 279cmd_record_mcount = \ 280 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \ 281 "$(CC_FLAGS_FTRACE)" ]; then \ 282 $(sub_cmd_record_mcount) \ 283 fi; 284endif 285endif # CONFIG_FTRACE_MCOUNT_RECORD 286 287ifdef CONFIG_STACK_VALIDATION 288ifneq ($(SKIP_STACK_VALIDATION),1) 289 290__objtool_obj := $(objtree)/tools/objtool/objtool 291 292objtool_args = $(if $(CONFIG_UNWINDER_ORC),orc generate,check) 293 294objtool_args += $(if $(part-of-module), --module,) 295 296ifndef CONFIG_FRAME_POINTER 297objtool_args += --no-fp 298endif 299ifdef CONFIG_GCOV_KERNEL 300objtool_args += --no-unreachable 301else 302objtool_args += $(call cc-ifversion, -lt, 0405, --no-unreachable) 303endif 304ifdef CONFIG_RETPOLINE 305 objtool_args += --retpoline 306endif 307 308 309ifdef CONFIG_MODVERSIONS 310objtool_o = $(@D)/.tmp_$(@F) 311else 312objtool_o = $(@) 313endif 314 315# 'OBJECT_FILES_NON_STANDARD := y': skip objtool checking for a directory 316# 'OBJECT_FILES_NON_STANDARD_foo.o := 'y': skip objtool checking for a file 317# 'OBJECT_FILES_NON_STANDARD_foo.o := 'n': override directory skip for a file 318cmd_objtool = $(if $(patsubst y%,, \ 319 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 320 $(__objtool_obj) $(objtool_args) "$(objtool_o)";) 321objtool_obj = $(if $(patsubst y%,, \ 322 $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ 323 $(__objtool_obj)) 324 325endif # SKIP_STACK_VALIDATION 326endif # CONFIG_STACK_VALIDATION 327 328# Rebuild all objects when objtool changes, or is enabled/disabled. 329objtool_dep = $(objtool_obj) \ 330 $(wildcard include/config/orc/unwinder.h \ 331 include/config/stack/validation.h) 332 333define rule_cc_o_c 334 $(call echo-cmd,checksrc) $(cmd_checksrc) \ 335 $(call cmd_and_fixdep,cc_o_c) \ 336 $(call echo-cmd,objtool) $(cmd_objtool) \ 337 $(cmd_modversions_c) \ 338 $(call echo-cmd,record_mcount) $(cmd_record_mcount) 339endef 340 341define rule_as_o_S 342 $(call cmd_and_fixdep,as_o_S) \ 343 $(call echo-cmd,objtool) $(cmd_objtool) \ 344 $(cmd_modversions_S) 345endef 346 347# List module undefined symbols (or empty line if not enabled) 348ifdef CONFIG_TRIM_UNUSED_KSYMS 349cmd_undef_syms = $(NM) $@ | sed -n 's/^ \+U //p' | xargs echo 350else 351cmd_undef_syms = echo 352endif 353 354# Built-in and composite module parts 355$(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE 356 $(call cmd,force_checksrc) 357 $(call if_changed_rule,cc_o_c) 358 359# Single-part modules are special since we need to mark them in $(MODVERDIR) 360 361$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) $(objtool_dep) FORCE 362 $(call cmd,force_checksrc) 363 $(call if_changed_rule,cc_o_c) 364 @{ echo $(@:.o=.ko); echo $@; \ 365 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 366 367quiet_cmd_cc_lst_c = MKLST $@ 368 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \ 369 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \ 370 System.map $(OBJDUMP) > $@ 371 372$(obj)/%.lst: $(src)/%.c FORCE 373 $(call if_changed_dep,cc_lst_c) 374 375# Compile assembler sources (.S) 376# --------------------------------------------------------------------------- 377 378modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) 379 380$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 381$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 382 383# .S file exports must have their C prototypes defined in asm/asm-prototypes.h 384# or a file that it includes, in order to get versioned symbols. We build a 385# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from 386# the .S file (with trailing ';'), and run genksyms on that, to extract vers. 387# 388# This is convoluted. The .S file must first be preprocessed to run guards and 389# expand names, then the resulting exports must be constructed into plain 390# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed 391# to make the genksyms input. 392# 393# These mirror gensymtypes_c and co above, keep them in synch. 394cmd_gensymtypes_S = \ 395 (echo "\#include <linux/kernel.h>" ; \ 396 echo "\#include <asm/asm-prototypes.h>" ; \ 397 $(CPP) $(a_flags) $< | \ 398 grep "\<___EXPORT_SYMBOL\>" | \ 399 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \ 400 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ 401 $(GENKSYMS) $(if $(1), -T $(2)) \ 402 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 403 $(patsubst y,-R,$(CONFIG_MODULE_REL_CRCS)) \ 404 $(if $(KBUILD_PRESERVE),-p) \ 405 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 406 407quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@ 408cmd_cc_symtypes_S = \ 409 set -e; \ 410 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \ 411 test -s $@ || rm -f $@ 412 413$(obj)/%.symtypes : $(src)/%.S FORCE 414 $(call cmd,cc_symtypes_S) 415 416 417quiet_cmd_cpp_s_S = CPP $(quiet_modtag) $@ 418cmd_cpp_s_S = $(CPP) $(a_flags) -o $@ $< 419 420$(obj)/%.s: $(src)/%.S FORCE 421 $(call if_changed_dep,cpp_s_S) 422 423quiet_cmd_as_o_S = AS $(quiet_modtag) $@ 424 425ifndef CONFIG_MODVERSIONS 426cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 427 428else 429 430ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h) 431 432ifeq ($(ASM_PROTOTYPES),) 433cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 434 435else 436 437# versioning matches the C process described above, with difference that 438# we parse asm-prototypes.h C header to get function definitions. 439 440cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $< 441 442cmd_modversions_S = \ 443 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 444 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 445 > $(@D)/.tmp_$(@F:.o=.ver); \ 446 \ 447 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 448 -T $(@D)/.tmp_$(@F:.o=.ver); \ 449 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 450 else \ 451 mv -f $(@D)/.tmp_$(@F) $@; \ 452 fi; 453endif 454endif 455 456$(obj)/%.o: $(src)/%.S $(objtool_dep) FORCE 457 $(call if_changed_rule,as_o_S) 458 459targets += $(real-objs-y) $(real-objs-m) $(lib-y) 460targets += $(extra-y) $(MAKECMDGOALS) $(always) 461 462# Linker scripts preprocessor (.lds.S -> .lds) 463# --------------------------------------------------------------------------- 464quiet_cmd_cpp_lds_S = LDS $@ 465 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \ 466 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $< 467 468$(obj)/%.lds: $(src)/%.lds.S FORCE 469 $(call if_changed_dep,cpp_lds_S) 470 471# ASN.1 grammar 472# --------------------------------------------------------------------------- 473quiet_cmd_asn1_compiler = ASN.1 $@ 474 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \ 475 $(subst .h,.c,$@) $(subst .c,.h,$@) 476 477.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h 478 479$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler 480 $(call cmd,asn1_compiler) 481 482# Build the compiled-in targets 483# --------------------------------------------------------------------------- 484 485# To build objects in subdirs, we need to descend into the directories 486$(sort $(subdir-obj-y)): $(subdir-ym) ; 487 488# 489# Rule to compile a set of .o files into one .o file 490# 491ifdef builtin-target 492 493ifdef CONFIG_LTO_CLANG 494 ifdef CONFIG_MODVERSIONS 495 # combine symversions for later processing 496 update_lto_symversions = \ 497 rm -f $@.symversions; \ 498 for i in $(filter-out FORCE,$^); do \ 499 if [ -f $$i.symversions ]; then \ 500 cat $$i.symversions \ 501 >> $@.symversions; \ 502 fi; \ 503 done; 504 endif 505 # rebuild the symbol table with llvm-ar to include IR files 506 update_lto_symtable = ; \ 507 mv -f $@ $@.tmp; \ 508 $(LLVM_AR) rcsT$(KBUILD_ARFLAGS) $@ \ 509 $$($(AR) t $@.tmp); \ 510 rm -f $@.tmp 511endif 512 513ifdef CONFIG_THIN_ARCHIVES 514 cmd_make_builtin = $(update_lto_symversions) \ 515 rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) 516 cmd_make_empty_builtin = rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) 517 quiet_cmd_link_o_target = AR $@ 518else 519 cmd_make_builtin = $(LD) $(ld_flags) -r -o 520 cmd_make_empty_builtin = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) 521 quiet_cmd_link_o_target = LD $@ 522endif 523 524# If the list of objects to link is empty, just create an empty built-in.o 525cmd_link_o_target = $(if $(strip $(obj-y)),\ 526 $(cmd_make_builtin) $@ $(filter $(obj-y), $^) \ 527 $(cmd_secanalysis),\ 528 $(cmd_make_empty_builtin) $@) 529 530$(builtin-target): $(obj-y) FORCE 531 $(call if_changed,link_o_target) 532 533targets += $(builtin-target) 534endif # builtin-target 535 536# 537# Rule to create modules.order file 538# 539# Create commands to either record .ko file or cat modules.order from 540# a subdirectory 541modorder-cmds = \ 542 $(foreach m, $(modorder), \ 543 $(if $(filter %/modules.order, $m), \ 544 cat $m;, echo kernel/$m;)) 545 546$(modorder-target): $(subdir-ym) FORCE 547 $(Q)(cat /dev/null; $(modorder-cmds)) > $@ 548 549# 550# Rule to compile a set of .o files into one .a file 551# 552ifdef lib-target 553quiet_cmd_link_l_target = AR $@ 554 555ifdef CONFIG_THIN_ARCHIVES 556 cmd_link_l_target = \ 557 $(update_lto_symversions) \ 558 rm -f $@; \ 559 $(AR) rcsTP$(KBUILD_ARFLAGS) $@ $(lib-y) \ 560 $(update_lto_symtable) 561else 562 cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y) 563endif 564 565$(lib-target): $(lib-y) FORCE 566 $(call if_changed,link_l_target) 567 568targets += $(lib-target) 569 570dummy-object = $(obj)/.lib_exports.o 571ksyms-lds = $(dot-target).lds 572ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX 573ref_prefix = EXTERN(_ 574else 575ref_prefix = EXTERN( 576endif 577 578filter_export_list = sed -ne '/___ksymtab/s/.*+\([^ "]*\).*/$(ref_prefix)\1)/p' 579link_export_list = rm -f $(dummy-object);\ 580 echo | $(CC) $(a_flags) -c -o $(dummy-object) -x assembler -;\ 581 $(LD) $(ld_flags) -r -o $@ -T $(ksyms-lds) $(dummy-object);\ 582 rm $(dummy-object) $(ksyms-lds) 583 584quiet_cmd_export_list = EXPORTS $@ 585 586ifdef CONFIG_LTO_CLANG 587# objdump doesn't understand IR files and llvm-dis doesn't support archives, 588# so we'll walk through each file in the archive separately 589cmd_export_list = \ 590 rm -f $(ksyms-lds); \ 591 for o in $$($(AR) t $<); do \ 592 if $(OBJDUMP) -h $$o >/dev/null 2>/dev/null; then \ 593 $(OBJDUMP) -h $$o | \ 594 $(filter_export_list) \ 595 >>$(ksyms-lds); \ 596 else \ 597 $(LLVM_DIS) -o=- $$o | \ 598 $(filter_export_list) \ 599 >>$(ksyms-lds); \ 600 fi; \ 601 done; \ 602 $(link_export_list) 603else 604cmd_export_list = $(OBJDUMP) -h $< | $(filter_export_list) >$(ksyms-lds); \ 605 $(link_export_list) 606endif 607 608$(obj)/lib-ksyms.o: $(lib-target) FORCE 609 $(call if_changed,export_list) 610 611targets += $(obj)/lib-ksyms.o 612 613endif 614 615# 616# Rule to link composite objects 617# 618# Composite objects are specified in kbuild makefile as follows: 619# <composite-object>-objs := <list of .o files> 620# or 621# <composite-object>-y := <list of .o files> 622# or 623# <composite-object>-m := <list of .o files> 624# The -m syntax only works if <composite object> is a module 625link_multi_deps = \ 626$(filter $(addprefix $(obj)/, \ 627$($(subst $(obj)/,,$(@:.o=-objs))) \ 628$($(subst $(obj)/,,$(@:.o=-y))) \ 629$($(subst $(obj)/,,$(@:.o=-m)))), $^) 630 631cmd_link_multi-link = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis) 632 633ifdef CONFIG_THIN_ARCHIVES 634 quiet_cmd_link_multi-y = AR $@ 635 cmd_link_multi-y = $(update_lto_symversions) \ 636 rm -f $@; $(AR) rcSTP$(KBUILD_ARFLAGS) $@ $(link_multi_deps) \ 637 $(update_lto_symtable) 638else 639 quiet_cmd_link_multi-y = LD $@ 640 cmd_link_multi-y = $(cmd_link_multi-link) 641endif 642 643quiet_cmd_link_multi-m = LD [M] $@ 644 645ifdef CONFIG_LTO_CLANG 646 # don't compile IR until needed 647 cmd_link_multi-m = $(cmd_link_multi-y) 648else 649 cmd_link_multi-m = $(cmd_link_multi-link) 650endif 651 652$(multi-used-y): FORCE 653 $(call if_changed,link_multi-y) 654 655$(multi-used-m): FORCE 656 $(call if_changed,link_multi-m) 657 @{ echo $(@:.o=.ko); echo $(link_multi_deps); \ 658 $(cmd_undef_syms); } > $(MODVERDIR)/$(@F:.o=.mod) 659 660$(call multi_depend, $(multi-used-y), .o, -objs -y) 661$(call multi_depend, $(multi-used-m), .o, -objs -y -m) 662 663targets += $(multi-used-y) $(multi-used-m) 664 665 666# Descending 667# --------------------------------------------------------------------------- 668 669PHONY += $(subdir-ym) 670$(subdir-ym): 671 $(Q)$(MAKE) $(build)=$@ 672 673# Add FORCE to the prequisites of a target to force it to be always rebuilt. 674# --------------------------------------------------------------------------- 675 676PHONY += FORCE 677 678FORCE: 679 680# Read all saved command lines and dependencies for the $(targets) we 681# may be building above, using $(if_changed{,_dep}). As an 682# optimization, we don't need to read them if the target does not 683# exist, we will rebuild anyway in that case. 684 685targets := $(wildcard $(sort $(targets))) 686cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 687 688ifneq ($(cmd_files),) 689 include $(cmd_files) 690endif 691 692# Declare the contents of the .PHONY variable as phony. We keep that 693# information in a variable se we can use it in if_changed and friends. 694 695.PHONY: $(PHONY) 696