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)$(hostprogs-m),) 64include scripts/Makefile.host 65endif 66 67ifneq ($(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 := $(obj)/lib.a 84endif 85 86ifneq ($(strip $(obj-y) $(obj-m) $(obj-) $(subdir-m) $(lib-target)),) 87builtin-target := $(obj)/built-in.o 88endif 89 90modorder-target := $(obj)/modules.order 91 92# We keep a list of all modules in $(MODVERDIR) 93 94__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \ 95 $(if $(KBUILD_MODULES),$(obj-m) $(modorder-target)) \ 96 $(subdir-ym) $(always) 97 @: 98 99# Linus' kernel sanity checking tool 100ifneq ($(KBUILD_CHECKSRC),0) 101 ifeq ($(KBUILD_CHECKSRC),2) 102 quiet_cmd_force_checksrc = CHECK $< 103 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 104 else 105 quiet_cmd_checksrc = CHECK $< 106 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ; 107 endif 108endif 109 110# Do section mismatch analysis for each module/built-in.o 111ifdef CONFIG_DEBUG_SECTION_MISMATCH 112 cmd_secanalysis = ; scripts/mod/modpost $@ 113endif 114 115# Compile C sources (.c) 116# --------------------------------------------------------------------------- 117 118# Default is built-in, unless we know otherwise 119modkern_cflags = \ 120 $(if $(part-of-module), \ 121 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 122 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL)) 123quiet_modtag := $(empty) $(empty) 124 125$(real-objs-m) : part-of-module := y 126$(real-objs-m:.o=.i) : part-of-module := y 127$(real-objs-m:.o=.s) : part-of-module := y 128$(real-objs-m:.o=.lst): part-of-module := y 129 130$(real-objs-m) : quiet_modtag := [M] 131$(real-objs-m:.o=.i) : quiet_modtag := [M] 132$(real-objs-m:.o=.s) : quiet_modtag := [M] 133$(real-objs-m:.o=.lst): quiet_modtag := [M] 134 135$(obj-m) : quiet_modtag := [M] 136 137# Default for not multi-part modules 138modname = $(basetarget) 139 140$(multi-objs-m) : modname = $(modname-multi) 141$(multi-objs-m:.o=.i) : modname = $(modname-multi) 142$(multi-objs-m:.o=.s) : modname = $(modname-multi) 143$(multi-objs-m:.o=.lst) : modname = $(modname-multi) 144$(multi-objs-y) : modname = $(modname-multi) 145$(multi-objs-y:.o=.i) : modname = $(modname-multi) 146$(multi-objs-y:.o=.s) : modname = $(modname-multi) 147$(multi-objs-y:.o=.lst) : modname = $(modname-multi) 148 149quiet_cmd_cc_s_c = CC $(quiet_modtag) $@ 150cmd_cc_s_c = $(CC) $(c_flags) $(DISABLE_LTO) -fverbose-asm -S -o $@ $< 151 152$(obj)/%.s: $(src)/%.c FORCE 153 $(call if_changed_dep,cc_s_c) 154 155quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@ 156cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $< 157 158$(obj)/%.i: $(src)/%.c FORCE 159 $(call if_changed_dep,cc_i_c) 160 161# These mirror gensymtypes_S and co below, keep them in synch. 162cmd_gensymtypes_c = \ 163 $(CPP) -D__GENKSYMS__ $(c_flags) $< | \ 164 $(GENKSYMS) $(if $(1), -T $(2)) \ 165 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 166 $(if $(KBUILD_PRESERVE),-p) \ 167 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 168 169quiet_cmd_cc_symtypes_c = SYM $(quiet_modtag) $@ 170cmd_cc_symtypes_c = \ 171 set -e; \ 172 $(call cmd_gensymtypes_c,true,$@) >/dev/null; \ 173 test -s $@ || rm -f $@ 174 175$(obj)/%.symtypes : $(src)/%.c FORCE 176 $(call cmd,cc_symtypes_c) 177 178# LLVM assembly 179# Generate .ll files from .c 180quiet_cmd_cc_ll_c = CC $(quiet_modtag) $@ 181 cmd_cc_ll_c = $(CC) $(c_flags) -emit-llvm -S -o $@ $< 182 183$(obj)/%.ll: $(src)/%.c FORCE 184 $(call if_changed_dep,cc_ll_c) 185 186# C (.c) files 187# The C file is compiled and updated dependency information is generated. 188# (See cmd_cc_o_c + relevant part of rule_cc_o_c) 189 190quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ 191 192ifndef CONFIG_MODVERSIONS 193cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< 194 195else 196# When module versioning is enabled the following steps are executed: 197# o compile a .tmp_<file>.o from <file>.c 198# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does 199# not export symbols, we just rename .tmp_<file>.o to <file>.o and 200# are done. 201# o otherwise, we calculate symbol versions using the good old 202# genksyms on the preprocessed source and postprocess them in a way 203# that they are usable as a linker script 204# o generate <file>.o from .tmp_<file>.o using the linker to 205# replace the unresolved symbols __crc_exported_symbol with 206# the actual value of the checksum generated by genksyms 207 208cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $< 209 210cmd_modversions_c = \ 211 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 212 $(call cmd_gensymtypes_c,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 213 > $(@D)/.tmp_$(@F:.o=.ver); \ 214 \ 215 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 216 -T $(@D)/.tmp_$(@F:.o=.ver); \ 217 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 218 else \ 219 mv -f $(@D)/.tmp_$(@F) $@; \ 220 fi; 221endif 222 223ifdef CONFIG_FTRACE_MCOUNT_RECORD 224ifdef BUILD_C_RECORDMCOUNT 225ifeq ("$(origin RECORDMCOUNT_WARN)", "command line") 226 RECORDMCOUNT_FLAGS = -w 227endif 228# Due to recursion, we must skip empty.o. 229# The empty.o file is created in the make process in order to determine 230# the target endianness and word size. It is made before all other C 231# files, including recordmcount. 232sub_cmd_record_mcount = \ 233 if [ $(@) != "scripts/mod/empty.o" ]; then \ 234 $(objtree)/scripts/recordmcount $(RECORDMCOUNT_FLAGS) "$(@)"; \ 235 fi; 236recordmcount_source := $(srctree)/scripts/recordmcount.c \ 237 $(srctree)/scripts/recordmcount.h 238else 239sub_cmd_record_mcount = set -e ; perl $(srctree)/scripts/recordmcount.pl "$(ARCH)" \ 240 "$(if $(CONFIG_CPU_BIG_ENDIAN),big,little)" \ 241 "$(if $(CONFIG_64BIT),64,32)" \ 242 "$(OBJDUMP)" "$(OBJCOPY)" "$(CC) $(KBUILD_CFLAGS)" \ 243 "$(LD)" "$(NM)" "$(RM)" "$(MV)" \ 244 "$(if $(part-of-module),1,0)" "$(@)"; 245recordmcount_source := $(srctree)/scripts/recordmcount.pl 246endif 247cmd_record_mcount = \ 248 if [ "$(findstring $(CC_FLAGS_FTRACE),$(_c_flags))" = \ 249 "$(CC_FLAGS_FTRACE)" ]; then \ 250 $(sub_cmd_record_mcount) \ 251 fi; 252endif 253 254define rule_cc_o_c 255 $(call echo-cmd,checksrc) $(cmd_checksrc) \ 256 $(call echo-cmd,cc_o_c) $(cmd_cc_o_c); \ 257 $(cmd_modversions_c) \ 258 $(call echo-cmd,record_mcount) \ 259 $(cmd_record_mcount) \ 260 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,cc_o_c)' > \ 261 $(dot-target).tmp; \ 262 rm -f $(depfile); \ 263 mv -f $(dot-target).tmp $(dot-target).cmd 264endef 265 266define rule_as_o_S 267 $(call echo-cmd,as_o_S) $(cmd_as_o_S); \ 268 scripts/basic/fixdep $(depfile) $@ '$(call make-cmd,as_o_S)' > \ 269 $(dot-target).tmp; \ 270 $(cmd_modversions_S) \ 271 rm -f $(depfile); \ 272 mv -f $(dot-target).tmp $(dot-target).cmd 273endef 274 275# Built-in and composite module parts 276$(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE 277 $(call cmd,force_checksrc) 278 $(call if_changed_rule,cc_o_c) 279 280# Single-part modules are special since we need to mark them in $(MODVERDIR) 281 282$(single-used-m): $(obj)/%.o: $(src)/%.c $(recordmcount_source) FORCE 283 $(call cmd,force_checksrc) 284 $(call if_changed_rule,cc_o_c) 285 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod) 286 287quiet_cmd_cc_lst_c = MKLST $@ 288 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \ 289 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \ 290 System.map $(OBJDUMP) > $@ 291 292$(obj)/%.lst: $(src)/%.c FORCE 293 $(call if_changed_dep,cc_lst_c) 294 295# Compile assembler sources (.S) 296# --------------------------------------------------------------------------- 297 298modkern_aflags := $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) 299 300$(real-objs-m) : modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 301$(real-objs-m:.o=.s): modkern_aflags := $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE) 302 303# .S file exports must have their C prototypes defined in asm/asm-prototypes.h 304# or a file that it includes, in order to get versioned symbols. We build a 305# dummy C file that includes asm-prototypes and the EXPORT_SYMBOL lines from 306# the .S file (with trailing ';'), and run genksyms on that, to extract vers. 307# 308# This is convoluted. The .S file must first be preprocessed to run guards and 309# expand names, then the resulting exports must be constructed into plain 310# EXPORT_SYMBOL(symbol); to build our dummy C file, and that gets preprocessed 311# to make the genksyms input. 312# 313# These mirror gensymtypes_c and co above, keep them in synch. 314cmd_gensymtypes_S = \ 315 (echo "\#include <linux/kernel.h>" ; \ 316 echo "\#include <asm/asm-prototypes.h>" ; \ 317 $(CPP) $(a_flags) $< | \ 318 grep "\<___EXPORT_SYMBOL\>" | \ 319 sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL(\1);/' ) | \ 320 $(CPP) -D__GENKSYMS__ $(c_flags) -xc - | \ 321 $(GENKSYMS) $(if $(1), -T $(2)) \ 322 $(patsubst y,-s _,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX)) \ 323 $(if $(KBUILD_PRESERVE),-p) \ 324 -r $(firstword $(wildcard $(2:.symtypes=.symref) /dev/null)) 325 326quiet_cmd_cc_symtypes_S = SYM $(quiet_modtag) $@ 327cmd_cc_symtypes_S = \ 328 set -e; \ 329 $(call cmd_gensymtypes_S,true,$@) >/dev/null; \ 330 test -s $@ || rm -f $@ 331 332$(obj)/%.symtypes : $(src)/%.S FORCE 333 $(call cmd,cc_symtypes_S) 334 335quiet_cmd_as_s_S = CPP $(quiet_modtag) $@ 336cmd_as_s_S = $(CPP) $(a_flags) -o $@ $< 337 338$(obj)/%.s: $(src)/%.S FORCE 339 $(call if_changed_dep,as_s_S) 340 341quiet_cmd_as_o_S = AS $(quiet_modtag) $@ 342 343ifndef CONFIG_MODVERSIONS 344cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 345 346else 347 348ASM_PROTOTYPES := $(wildcard $(srctree)/arch/$(SRCARCH)/include/asm/asm-prototypes.h) 349 350ifeq ($(ASM_PROTOTYPES),) 351cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< 352 353else 354 355# versioning matches the C process described above, with difference that 356# we parse asm-prototypes.h C header to get function definitions. 357 358cmd_as_o_S = $(CC) $(a_flags) -c -o $(@D)/.tmp_$(@F) $< 359 360cmd_modversions_S = \ 361 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \ 362 $(call cmd_gensymtypes_S,$(KBUILD_SYMTYPES),$(@:.o=.symtypes)) \ 363 > $(@D)/.tmp_$(@F:.o=.ver); \ 364 \ 365 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \ 366 -T $(@D)/.tmp_$(@F:.o=.ver); \ 367 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \ 368 else \ 369 mv -f $(@D)/.tmp_$(@F) $@; \ 370 fi; 371endif 372endif 373 374$(obj)/%.o: $(src)/%.S FORCE 375 $(call if_changed_rule,as_o_S) 376 377targets += $(real-objs-y) $(real-objs-m) $(lib-y) 378targets += $(extra-y) $(MAKECMDGOALS) $(always) 379 380# Linker scripts preprocessor (.lds.S -> .lds) 381# --------------------------------------------------------------------------- 382quiet_cmd_cpp_lds_S = LDS $@ 383 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -C -U$(ARCH) \ 384 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $< 385 386$(obj)/%.lds: $(src)/%.lds.S FORCE 387 $(call if_changed_dep,cpp_lds_S) 388 389# ASN.1 grammar 390# --------------------------------------------------------------------------- 391quiet_cmd_asn1_compiler = ASN.1 $@ 392 cmd_asn1_compiler = $(objtree)/scripts/asn1_compiler $< \ 393 $(subst .h,.c,$@) $(subst .c,.h,$@) 394 395.PRECIOUS: $(objtree)/$(obj)/%-asn1.c $(objtree)/$(obj)/%-asn1.h 396 397$(obj)/%-asn1.c $(obj)/%-asn1.h: $(src)/%.asn1 $(objtree)/scripts/asn1_compiler 398 $(call cmd,asn1_compiler) 399 400# Build the compiled-in targets 401# --------------------------------------------------------------------------- 402 403# To build objects in subdirs, we need to descend into the directories 404$(sort $(subdir-obj-y)): $(subdir-ym) ; 405 406# 407# Rule to compile a set of .o files into one .o file 408# 409ifdef builtin-target 410quiet_cmd_link_o_target = LD $@ 411# If the list of objects to link is empty, just create an empty built-in.o 412cmd_link_o_target = $(if $(strip $(obj-y)),\ 413 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^) \ 414 $(cmd_secanalysis),\ 415 rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@) 416 417$(builtin-target): $(obj-y) FORCE 418 $(call if_changed,link_o_target) 419 420targets += $(builtin-target) 421endif # builtin-target 422 423# 424# Rule to create modules.order file 425# 426# Create commands to either record .ko file or cat modules.order from 427# a subdirectory 428modorder-cmds = \ 429 $(foreach m, $(modorder), \ 430 $(if $(filter %/modules.order, $m), \ 431 cat $m;, echo kernel/$m;)) 432 433$(modorder-target): $(subdir-ym) FORCE 434 $(Q)(cat /dev/null; $(modorder-cmds)) > $@ 435 436# 437# Rule to compile a set of .o files into one .a file 438# 439ifdef lib-target 440quiet_cmd_link_l_target = AR $@ 441cmd_link_l_target = rm -f $@; $(AR) rcs$(KBUILD_ARFLAGS) $@ $(lib-y) 442 443$(lib-target): $(lib-y) FORCE 444 $(call if_changed,link_l_target) 445 446targets += $(lib-target) 447endif 448 449# 450# Rule to link composite objects 451# 452# Composite objects are specified in kbuild makefile as follows: 453# <composite-object>-objs := <list of .o files> 454# or 455# <composite-object>-y := <list of .o files> 456link_multi_deps = \ 457$(filter $(addprefix $(obj)/, \ 458$($(subst $(obj)/,,$(@:.o=-objs))) \ 459$($(subst $(obj)/,,$(@:.o=-y)))), $^) 460 461quiet_cmd_link_multi-y = LD $@ 462cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps) $(cmd_secanalysis) 463 464quiet_cmd_link_multi-m = LD [M] $@ 465cmd_link_multi-m = $(cmd_link_multi-y) 466 467$(multi-used-y): FORCE 468 $(call if_changed,link_multi-y) 469$(call multi_depend, $(multi-used-y), .o, -objs -y) 470 471$(multi-used-m): FORCE 472 $(call if_changed,link_multi-m) 473 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod) 474$(call multi_depend, $(multi-used-m), .o, -objs -y) 475 476targets += $(multi-used-y) $(multi-used-m) 477 478 479# Descending 480# --------------------------------------------------------------------------- 481 482PHONY += $(subdir-ym) 483$(subdir-ym): 484 $(Q)$(MAKE) $(build)=$@ 485 486# Add FORCE to the prequisites of a target to force it to be always rebuilt. 487# --------------------------------------------------------------------------- 488 489PHONY += FORCE 490 491FORCE: 492 493# Read all saved command lines and dependencies for the $(targets) we 494# may be building above, using $(if_changed{,_dep}). As an 495# optimization, we don't need to read them if the target does not 496# exist, we will rebuild anyway in that case. 497 498targets := $(wildcard $(sort $(targets))) 499cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd)) 500 501ifneq ($(cmd_files),) 502 include $(cmd_files) 503endif 504 505# Declare the contents of the .PHONY variable as phony. We keep that 506# information in a variable se we can use it in if_changed and friends. 507 508.PHONY: $(PHONY) 509