Makefile

   1 VERSION = 3
   2 PATCHLEVEL = 16
   3 SUBLEVEL = 0
   4 EXTRAVERSION =
   5 NAME = Shuffling Zombie Juror
   6
   7 # *DOCUMENTATION*
   8 # To see a list of typical targets execute "make help"
   9 # More info can be located in ./README
  10 # Comments in this file are targeted only to the developer, do not
  11 # expect to learn how to build the kernel reading this file.
  12
  13 # Do not:
  14 # o  use make's built-in rules and variables
  15 #    (this increases performance and avoids hard-to-debug behaviour);
  16 # o  print "Entering directory ...";
  17 MAKEFLAGS += -rR --no-print-directory
  18
  19 # Avoid funny character set dependencies
  20 unexport LC_ALL
  21 LC_COLLATE=C
  22 LC_NUMERIC=C
  23 export LC_COLLATE LC_NUMERIC
  24
  25 # Avoid interference with shell env settings
  26 unexport GREP_OPTIONS
  27
  28 # We are using a recursive build, so we need to do a little thinking
  29 # to get the ordering right.
  30 #
  31 # Most importantly: sub-Makefiles should only ever modify files in
  32 # their own directory. If in some directory we have a dependency on
  33 # a file in another dir (which doesn't happen often, but it's often
  34 # unavoidable when linking the built-in.o targets which finally
  35 # turn into vmlinux), we will call a sub make in that other dir, and
  36 # after that we are sure that everything which is in that other dir
  37 # is now up to date.
  38 #
  39 # The only cases where we need to modify files which have global
  40 # effects are thus separated out and done before the recursive
  41 # descending is started. They are now explicitly listed as the
  42 # prepare rule.
  43
  44 # Beautify output
  45 # ---------------------------------------------------------------------------
  46 #
  47 # Normally, we echo the whole command before executing it. By making
  48 # that echo $($(quiet)$(cmd)), we now have the possibility to set
  49 # $(quiet) to choose other forms of output instead, e.g.
  50 #
  51 #         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
  52 #         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
  53 #
  54 # If $(quiet) is empty, the whole command will be printed.
  55 # If it is set to "quiet_", only the short version will be printed.
  56 # If it is set to "silent_", nothing will be printed at all, since
  57 # the variable $(silent_cmd_cc_o_c) doesn't exist.
  58 #
  59 # A simple variant is to prefix commands with $(Q) - that's useful
  60 # for commands that shall be hidden in non-verbose mode.
  61 #
  62 #       $(Q)ln $@ :<
  63 #
  64 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
  65 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
  66 #
  67 # To put more focus on warnings, be less verbose as default
  68 # Use 'make V=1' to see the full commands
  69
  70 ifeq ("$(origin V)", "command line")
  71   KBUILD_VERBOSE = $(V)
  72 endif
  73 ifndef KBUILD_VERBOSE
  74   KBUILD_VERBOSE = 0
  75 endif
  76
  77 ifeq ($(KBUILD_VERBOSE),1)
  78   quiet =
  79   Q =
  80 else
  81   quiet=quiet_
  82   Q = @
  83 endif
  84
  85 # If the user is running make -s (silent mode), suppress echoing of
  86 # commands
  87
  88 ifneq ($(filter 4.%,$(MAKE_VERSION)),)  # make-4
  89 ifneq ($(filter %s ,$(firstword x$(MAKEFLAGS))),)
  90   quiet=silent_
  91 endif
  92 else                                    # make-3.8x
  93 ifneq ($(filter s% -s%,$(MAKEFLAGS)),)
  94   quiet=silent_
  95 endif
  96 endif
  97
  98 export quiet Q KBUILD_VERBOSE
  99
 100 # Call a source code checker (by default, "sparse") as part of the
 101 # C compilation.
 102 #
 103 # Use 'make C=1' to enable checking of only re-compiled files.
 104 # Use 'make C=2' to enable checking of *all* source files, regardless
 105 # of whether they are re-compiled or not.
 106 #
 107 # See the file "Documentation/sparse.txt" for more details, including
 108 # where to get the "sparse" utility.
 109
 110 ifeq ("$(origin C)", "command line")
 111   KBUILD_CHECKSRC = $(C)
 112 endif
 113 ifndef KBUILD_CHECKSRC
 114   KBUILD_CHECKSRC = 0
 115 endif
 116
 117 # Use make M=dir to specify directory of external module to build
 118 # Old syntax make ... SUBDIRS=$PWD is still supported
 119 # Setting the environment variable KBUILD_EXTMOD take precedence
 120 ifdef SUBDIRS
 121   KBUILD_EXTMOD ?= $(SUBDIRS)
 122 endif
 123
 124 ifeq ("$(origin M)", "command line")
 125   KBUILD_EXTMOD := $(M)
 126 endif
 127
 128 # kbuild supports saving output files in a separate directory.
 129 # To locate output files in a separate directory two syntaxes are supported.
 130 # In both cases the working directory must be the root of the kernel src.
 131 # 1) O=
 132 # Use "make O=dir/to/store/output/files/"
 133 #
 134 # 2) Set KBUILD_OUTPUT
 135 # Set the environment variable KBUILD_OUTPUT to point to the directory
 136 # where the output files shall be placed.
 137 # export KBUILD_OUTPUT=dir/to/store/output/files/
 138 # make
 139 #
 140 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
 141 # variable.
 142
 143
 144 # KBUILD_SRC is set on invocation of make in OBJ directory
 145 # KBUILD_SRC is not intended to be used by the regular user (for now)
 146 ifeq ($(KBUILD_SRC),)
 147
 148 # OK, Make called in directory where kernel src resides
 149 # Do we want to locate output files in a separate directory?
 150 ifeq ("$(origin O)", "command line")
 151   KBUILD_OUTPUT := $(O)
 152 endif
 153
 154 # That's our default target when none is given on the command line
 155 PHONY := _all
 156 _all:
 157
 158 # Cancel implicit rules on top Makefile
 159 $(CURDIR)/Makefile Makefile: ;
 160
 161 ifneq ($(KBUILD_OUTPUT),)
 162 # Invoke a second make in the output directory, passing relevant variables
 163 # check that the output directory actually exists
 164 saved-output := $(KBUILD_OUTPUT)
 165 KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
 166                                                                 && /bin/pwd)
 167 $(if $(KBUILD_OUTPUT),, \
 168      $(error failed to create output directory "$(saved-output)"))
 169
 170 PHONY += $(MAKECMDGOALS) sub-make
 171
 172 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
 173         @:
 174
 175 # Fake the "Entering directory" message once, so that IDEs/editors are
 176 # able to understand relative filenames.
 177        echodir := @echo
 178  quiet_echodir := @echo
 179 silent_echodir := @:
 180 sub-make: FORCE
 181         $($(quiet)echodir) "make[1]: Entering directory \`$(KBUILD_OUTPUT)'"
 182         $(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT) \
 183         KBUILD_SRC=$(CURDIR) \
 184         KBUILD_EXTMOD="$(KBUILD_EXTMOD)" -f $(CURDIR)/Makefile \
 185         $(filter-out _all sub-make,$(MAKECMDGOALS))
 186
 187 # Leave processing to above invocation of make
 188 skip-makefile := 1
 189 endif # ifneq ($(KBUILD_OUTPUT),)
 190 endif # ifeq ($(KBUILD_SRC),)
 191
 192 # We process the rest of the Makefile if this is the final invocation of make
 193 ifeq ($(skip-makefile),)
 194
 195 # If building an external module we do not care about the all: rule
 196 # but instead _all depend on modules
 197 PHONY += all
 198 ifeq ($(KBUILD_EXTMOD),)
 199 _all: all
 200 else
 201 _all: modules
 202 endif
 203
 204 ifeq ($(KBUILD_SRC),)
 205         # building in the source tree
 206         srctree := .
 207 else
 208         ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
 209                 # building in a subdirectory of the source tree
 210                 srctree := ..
 211         else
 212                 srctree := $(KBUILD_SRC)
 213         endif
 214 endif
 215 objtree         := .
 216 src             := $(srctree)
 217 obj             := $(objtree)
 218
 219 VPATH           := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
 220
 221 export srctree objtree VPATH
 222
 223
 224 # SUBARCH tells the usermode build what the underlying arch is.  That is set
 225 # first, and if a usermode build is happening, the "ARCH=um" on the command
 226 # line overrides the setting of ARCH below.  If a native build is happening,
 227 # then ARCH is assigned, getting whatever value it gets normally, and
 228 # SUBARCH is subsequently ignored.
 229
 230 SUBARCH := $(shell uname -m | sed -e s/i.86/x86/ -e s/x86_64/x86/ \
 231                                   -e s/sun4u/sparc64/ \
 232                                   -e s/arm.*/arm/ -e s/sa110/arm/ \
 233                                   -e s/s390x/s390/ -e s/parisc64/parisc/ \
 234                                   -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
 235                                   -e s/sh[234].*/sh/ -e s/aarch64.*/arm64/ )
 236
 237 # Cross compiling and selecting different set of gcc/bin-utils
 238 # ---------------------------------------------------------------------------
 239 #
 240 # When performing cross compilation for other architectures ARCH shall be set
 241 # to the target architecture. (See arch/* for the possibilities).
 242 # ARCH can be set during invocation of make:
 243 # make ARCH=ia64
 244 # Another way is to have ARCH set in the environment.
 245 # The default ARCH is the host where make is executed.
 246
 247 # CROSS_COMPILE specify the prefix used for all executables used
 248 # during compilation. Only gcc and related bin-utils executables
 249 # are prefixed with $(CROSS_COMPILE).
 250 # CROSS_COMPILE can be set on the command line
 251 # make CROSS_COMPILE=ia64-linux-
 252 # Alternatively CROSS_COMPILE can be set in the environment.
 253 # A third alternative is to store a setting in .config so that plain
 254 # "make" in the configured kernel build directory always uses that.
 255 # Default value for CROSS_COMPILE is not to prefix executables
 256 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 257 ARCH            ?= $(SUBARCH)
 258 CROSS_COMPILE   ?= $(CONFIG_CROSS_COMPILE:"%"=%)
 259
 260 # Architecture as present in compile.h
 261 UTS_MACHINE     := $(ARCH)
 262 SRCARCH         := $(ARCH)
 263
 264 # Additional ARCH settings for x86
 265 ifeq ($(ARCH),i386)
 266         SRCARCH := x86
 267 endif
 268 ifeq ($(ARCH),x86_64)
 269         SRCARCH := x86
 270 endif
 271
 272 # Additional ARCH settings for sparc
 273 ifeq ($(ARCH),sparc32)
 274        SRCARCH := sparc
 275 endif
 276 ifeq ($(ARCH),sparc64)
 277        SRCARCH := sparc
 278 endif
 279
 280 # Additional ARCH settings for sh
 281 ifeq ($(ARCH),sh64)
 282        SRCARCH := sh
 283 endif
 284
 285 # Additional ARCH settings for tile
 286 ifeq ($(ARCH),tilepro)
 287        SRCARCH := tile
 288 endif
 289 ifeq ($(ARCH),tilegx)
 290        SRCARCH := tile
 291 endif
 292
 293 # Where to locate arch specific headers
 294 hdr-arch  := $(SRCARCH)
 295
 296 KCONFIG_CONFIG  ?= .config
 297 export KCONFIG_CONFIG
 298
 299 # SHELL used by kbuild
 300 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 301           else if [ -x /bin/bash ]; then echo /bin/bash; \
 302           else echo sh; fi ; fi)
 303
 304 HOSTCC       = gcc
 305 HOSTCXX      = g++
 306 HOSTCFLAGS   = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer
 307 HOSTCXXFLAGS = -O2
 308
 309 ifeq ($(shell $(HOSTCC) -v 2>&1 | grep -c "clang version"), 1)
 310 HOSTCFLAGS  += -Wno-unused-value -Wno-unused-parameter \
 311                 -Wno-missing-field-initializers -fno-delete-null-pointer-checks
 312 endif
 313
 314 # Decide whether to build built-in, modular, or both.
 315 # Normally, just do built-in.
 316
 317 KBUILD_MODULES :=
 318 KBUILD_BUILTIN := 1
 319
 320 # If we have only "make modules", don't compile built-in objects.
 321 # When we're building modules with modversions, we need to consider
 322 # the built-in objects during the descend as well, in order to
 323 # make sure the checksums are up to date before we record them.
 324
 325 ifeq ($(MAKECMDGOALS),modules)
 326   KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
 327 endif
 328
 329 # If we have "make <whatever> modules", compile modules
 330 # in addition to whatever we do anyway.
 331 # Just "make" or "make all" shall build modules as well
 332
 333 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
 334   KBUILD_MODULES := 1
 335 endif
 336
 337 ifeq ($(MAKECMDGOALS),)
 338   KBUILD_MODULES := 1
 339 endif
 340
 341 export KBUILD_MODULES KBUILD_BUILTIN
 342 export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
 343
 344 ifneq ($(CC),)
 345 ifeq ($(shell $(CC) -v 2>&1 | grep -c "clang version"), 1)
 346 COMPILER := clang
 347 else
 348 COMPILER := gcc
 349 endif
 350 export COMPILER
 351 endif
 352
 353 # Look for make include files relative to root of kernel src
 354 MAKEFLAGS += --include-dir=$(srctree)
 355
 356 # We need some generic definitions (do not try to remake the file).
 357 $(srctree)/scripts/Kbuild.include: ;
 358 include $(srctree)/scripts/Kbuild.include
 359
 360 # Make variables (CC, etc...)
 361 AS              = $(CROSS_COMPILE)as
 362 LD              = $(CROSS_COMPILE)ld
 363 CC              = $(CROSS_COMPILE)gcc
 364 CPP             = $(CC) -E
 365 AR              = $(CROSS_COMPILE)ar
 366 NM              = $(CROSS_COMPILE)nm
 367 STRIP           = $(CROSS_COMPILE)strip
 368 OBJCOPY         = $(CROSS_COMPILE)objcopy
 369 OBJDUMP         = $(CROSS_COMPILE)objdump
 370 AWK             = awk
 371 GENKSYMS        = scripts/genksyms/genksyms
 372 INSTALLKERNEL  := installkernel
 373 DEPMOD          = /sbin/depmod
 374 PERL            = perl
 375 CHECK           = sparse
 376
 377 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 378                   -Wbitwise -Wno-return-void $(CF)
 379 CFLAGS_MODULE   =
 380 AFLAGS_MODULE   =
 381 LDFLAGS_MODULE  =
 382 CFLAGS_KERNEL   =
 383 AFLAGS_KERNEL   =
 384 CFLAGS_GCOV     = -fprofile-arcs -ftest-coverage
 385
 386
 387 # Use USERINCLUDE when you must reference the UAPI directories only.
 388 USERINCLUDE    := \
 389                 -I$(srctree)/arch/$(hdr-arch)/include/uapi \
 390                 -Iarch/$(hdr-arch)/include/generated/uapi \
 391                 -I$(srctree)/include/uapi \
 392                 -Iinclude/generated/uapi \
 393                 -include $(srctree)/include/linux/kconfig.h
 394
 395 # Use LINUXINCLUDE when you must reference the include/ directory.
 396 # Needed to be compatible with the O= option
 397 LINUXINCLUDE    := \
 398                 -I$(srctree)/arch/$(hdr-arch)/include \
 399                 -Iarch/$(hdr-arch)/include/generated \
 400                 $(if $(KBUILD_SRC), -I$(srctree)/include) \
 401                 -Iinclude \
 402                 $(USERINCLUDE)
 403
 404 KBUILD_CPPFLAGS := -D__KERNEL__
 405
 406 KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 407                    -fno-strict-aliasing -fno-common \
 408                    -Werror-implicit-function-declaration \
 409                    -Wno-format-security
 410
 411 KBUILD_AFLAGS_KERNEL :=
 412 KBUILD_CFLAGS_KERNEL :=
 413 KBUILD_AFLAGS   := -D__ASSEMBLY__
 414 KBUILD_AFLAGS_MODULE  := -DMODULE
 415 KBUILD_CFLAGS_MODULE  := -DMODULE
 416 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
 417
 418 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 419 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 420 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 421
 422 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 423 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
 424 export CPP AR NM STRIP OBJCOPY OBJDUMP
 425 export MAKE AWK GENKSYMS INSTALLKERNEL PERL UTS_MACHINE
 426 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
 427
 428 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
 429 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV
 430 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 431 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 432 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 433 export KBUILD_ARFLAGS
 434
 435 # When compiling out-of-tree modules, put MODVERDIR in the module
 436 # tree rather than in the kernel tree. The kernel tree might
 437 # even be read-only.
 438 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
 439
 440 # Files to ignore in find ... statements
 441
 442 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 443                           -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 444                           -prune -o
 445 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 446                          --exclude CVS --exclude .pc --exclude .hg --exclude .git
 447
 448 # ===========================================================================
 449 # Rules shared between *config targets and build targets
 450
 451 # Basic helpers built in scripts/
 452 PHONY += scripts_basic
 453 scripts_basic:
 454         $(Q)$(MAKE) $(build)=scripts/basic
 455         $(Q)rm -f .tmp_quiet_recordmcount
 456
 457 # To avoid any implicit rule to kick in, define an empty command.
 458 scripts/basic/%: scripts_basic ;
 459
 460 PHONY += outputmakefile
 461 # outputmakefile generates a Makefile in the output directory, if using a
 462 # separate output directory. This allows convenient use of make in the
 463 # output directory.
 464 outputmakefile:
 465 ifneq ($(KBUILD_SRC),)
 466         $(Q)ln -fsn $(srctree) source
 467         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
 468             $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
 469 endif
 470
 471 # Support for using generic headers in asm-generic
 472 PHONY += asm-generic
 473 asm-generic:
 474         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
 475                     src=asm obj=arch/$(SRCARCH)/include/generated/asm
 476         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
 477                     src=uapi/asm obj=arch/$(SRCARCH)/include/generated/uapi/asm
 478
 479 # To make sure we do not include .config for any of the *config targets
 480 # catch them early, and hand them over to scripts/kconfig/Makefile
 481 # It is allowed to specify more targets when calling make, including
 482 # mixing *config targets and build targets.
 483 # For example 'make oldconfig all'.
 484 # Detect when mixed targets is specified, and make a second invocation
 485 # of make so .config is not included in this case either (for *config).
 486
 487 version_h := include/generated/uapi/linux/version.h
 488
 489 no-dot-config-targets := clean mrproper distclean \
 490                          cscope gtags TAGS tags help %docs check% coccicheck \
 491                          $(version_h) headers_% archheaders archscripts \
 492                          kernelversion %src-pkg
 493
 494 config-targets := 0
 495 mixed-targets  := 0
 496 dot-config     := 1
 497
 498 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 499         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 500                 dot-config := 0
 501         endif
 502 endif
 503
 504 ifeq ($(KBUILD_EXTMOD),)
 505         ifneq ($(filter config %config,$(MAKECMDGOALS)),)
 506                 config-targets := 1
 507                 ifneq ($(filter-out config %config,$(MAKECMDGOALS)),)
 508                         mixed-targets := 1
 509                 endif
 510         endif
 511 endif
 512
 513 ifeq ($(mixed-targets),1)
 514 # ===========================================================================
 515 # We're called with mixed targets (*config and build targets).
 516 # Handle them one by one.
 517
 518 PHONY += $(MAKECMDGOALS) __build_one_by_one
 519
 520 $(filter-out __build_one_by_one, $(MAKECMDGOALS)): __build_one_by_one
 521         @:
 522
 523 __build_one_by_one:
 524         $(Q)set -e; \
 525         for i in $(MAKECMDGOALS); do \
 526                 $(MAKE) -f $(srctree)/Makefile $$i; \
 527         done
 528
 529 else
 530 ifeq ($(config-targets),1)
 531 # ===========================================================================
 532 # *config targets only - make sure prerequisites are updated, and descend
 533 # in scripts/kconfig to make the *config target
 534
 535 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 536 # KBUILD_DEFCONFIG may point out an alternative default configuration
 537 # used for 'make defconfig'
 538 include $(srctree)/arch/$(SRCARCH)/Makefile
 539 export KBUILD_DEFCONFIG KBUILD_KCONFIG
 540
 541 config: scripts_basic outputmakefile FORCE
 542         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 543
 544 %config: scripts_basic outputmakefile FORCE
 545         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 546
 547 else
 548 # ===========================================================================
 549 # Build targets only - this includes vmlinux, arch specific targets, clean
 550 # targets and others. In general all targets except *config targets.
 551
 552 ifeq ($(KBUILD_EXTMOD),)
 553 # Additional helpers built in scripts/
 554 # Carefully list dependencies so we do not try to build scripts twice
 555 # in parallel
 556 PHONY += scripts
 557 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \
 558          asm-generic
 559         $(Q)$(MAKE) $(build)=$(@)
 560
 561 # Objects we will link into vmlinux / subdirs we need to visit
 562 init-y          := init/
 563 drivers-y       := drivers/ sound/ firmware/
 564 net-y           := net/
 565 libs-y          := lib/
 566 core-y          := usr/
 567 endif # KBUILD_EXTMOD
 568
 569 ifeq ($(dot-config),1)
 570 # Read in config
 571 -include include/config/auto.conf
 572
 573 ifeq ($(KBUILD_EXTMOD),)
 574 # Read in dependencies to all Kconfig* files, make sure to run
 575 # oldconfig if changes are detected.
 576 -include include/config/auto.conf.cmd
 577
 578 # To avoid any implicit rule to kick in, define an empty command
 579 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
 580
 581 # If .config is newer than include/config/auto.conf, someone tinkered
 582 # with it and forgot to run make oldconfig.
 583 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
 584 # we execute the config step to be sure to catch updated Kconfig files
 585 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
 586         $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
 587 else
 588 # external modules needs include/generated/autoconf.h and include/config/auto.conf
 589 # but do not care if they are up-to-date. Use auto.conf to trigger the test
 590 PHONY += include/config/auto.conf
 591
 592 include/config/auto.conf:
 593         $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 594         echo >&2;                                                       \
 595         echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 596         echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 597         echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 598         echo >&2 ;                                                      \
 599         /bin/false)
 600
 601 endif # KBUILD_EXTMOD
 602
 603 else
 604 # Dummy target needed, because used as prerequisite
 605 include/config/auto.conf: ;
 606 endif # $(dot-config)
 607
 608 # The all: target is the default when no target is given on the
 609 # command line.
 610 # This allow a user to issue only 'make' to build a kernel including modules
 611 # Defaults to vmlinux, but the arch makefile usually adds further targets
 612 all: vmlinux
 613
 614 include $(srctree)/arch/$(SRCARCH)/Makefile
 615
 616 KBUILD_CFLAGS   += $(call cc-option,-fno-delete-null-pointer-checks,)
 617
 618 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 619 KBUILD_CFLAGS   += -Os $(call cc-disable-warning,maybe-uninitialized,)
 620 else
 621 KBUILD_CFLAGS   += -O2
 622 endif
 623
 624 # Tell gcc to never replace conditional load with a non-conditional one
 625 KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 626
 627 ifdef CONFIG_READABLE_ASM
 628 # Disable optimizations that make assembler listings hard to read.
 629 # reorder blocks reorders the control in the function
 630 # ipa clone creates specialized cloned functions
 631 # partial inlining inlines only parts of functions
 632 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
 633                  $(call cc-option,-fno-ipa-cp-clone,) \
 634                  $(call cc-option,-fno-partial-inlining)
 635 endif
 636
 637 ifneq ($(CONFIG_FRAME_WARN),0)
 638 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
 639 endif
 640
 641 # Handle stack protector mode.
 642 #
 643 # Since kbuild can potentially perform two passes (first with the old
 644 # .config values and then with updated .config values), we cannot error out
 645 # if a desired compiler option is unsupported. If we were to error, kbuild
 646 # could never get to the second pass and actually notice that we changed
 647 # the option to something that was supported.
 648 #
 649 # Additionally, we don't want to fallback and/or silently change which compiler
 650 # flags will be used, since that leads to producing kernels with different
 651 # security feature characteristics depending on the compiler used. ("But I
 652 # selected CC_STACKPROTECTOR_STRONG! Why did it build with _REGULAR?!")
 653 #
 654 # The middle ground is to warn here so that the failed option is obvious, but
 655 # to let the build fail with bad compiler flags so that we can't produce a
 656 # kernel when there is a CONFIG and compiler mismatch.
 657 #
 658 ifdef CONFIG_CC_STACKPROTECTOR_REGULAR
 659   stackp-flag := -fstack-protector
 660   ifeq ($(call cc-option, $(stackp-flag)),)
 661     $(warning Cannot use CONFIG_CC_STACKPROTECTOR_REGULAR: \
 662              -fstack-protector not supported by compiler)
 663   endif
 664 else
 665 ifdef CONFIG_CC_STACKPROTECTOR_STRONG
 666   stackp-flag := -fstack-protector-strong
 667   ifeq ($(call cc-option, $(stackp-flag)),)
 668     $(warning Cannot use CONFIG_CC_STACKPROTECTOR_STRONG: \
 669               -fstack-protector-strong not supported by compiler)
 670   endif
 671 else
 672   # Force off for distro compilers that enable stack protector by default.
 673   stackp-flag := $(call cc-option, -fno-stack-protector)
 674 endif
 675 endif
 676 KBUILD_CFLAGS += $(stackp-flag)
 677
 678 ifeq ($(COMPILER),clang)
 679 KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
 680 KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,)
 681 KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
 682 KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
 683 KBUILD_CFLAGS += $(call cc-disable-warning, gnu)
 684 # Quiet clang warning: comparison of unsigned expression < 0 is always false
 685 KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 686 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 687 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 688 # See modpost pattern 2
 689 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
 690 else
 691
 692 # This warning generated too much noise in a regular build.
 693 # Use make W=1 to enable this warning (see scripts/Makefile.build)
 694 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 695 endif
 696
 697 ifdef CONFIG_FRAME_POINTER
 698 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 699 else
 700 # Some targets (ARM with Thumb2, for example), can't be built with frame
 701 # pointers.  For those, we don't have FUNCTION_TRACER automatically
 702 # select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 703 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
 704 # -fomit-frame-pointer with FUNCTION_TRACER.
 705 ifndef CONFIG_FUNCTION_TRACER
 706 KBUILD_CFLAGS   += -fomit-frame-pointer
 707 endif
 708 endif
 709
 710 KBUILD_CFLAGS   += $(call cc-option, -fno-var-tracking-assignments)
 711
 712 ifdef CONFIG_DEBUG_INFO
 713 KBUILD_CFLAGS   += -g
 714 KBUILD_AFLAGS   += -Wa,-gdwarf-2
 715 endif
 716
 717 ifdef CONFIG_DEBUG_INFO_REDUCED
 718 KBUILD_CFLAGS   += $(call cc-option, -femit-struct-debug-baseonly) \
 719                    $(call cc-option,-fno-var-tracking)
 720 endif
 721
 722 ifdef CONFIG_FUNCTION_TRACER
 723 ifdef CONFIG_HAVE_FENTRY
 724 CC_USING_FENTRY := $(call cc-option, -mfentry -DCC_USING_FENTRY)
 725 endif
 726 KBUILD_CFLAGS   += -pg $(CC_USING_FENTRY)
 727 KBUILD_AFLAGS   += $(CC_USING_FENTRY)
 728 ifdef CONFIG_DYNAMIC_FTRACE
 729         ifdef CONFIG_HAVE_C_RECORDMCOUNT
 730                 BUILD_C_RECORDMCOUNT := y
 731                 export BUILD_C_RECORDMCOUNT
 732         endif
 733 endif
 734 endif
 735
 736 # We trigger additional mismatches with less inlining
 737 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 738 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 739 endif
 740
 741 # arch Makefile may override CC so keep this after arch Makefile is included
 742 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 743 CHECKFLAGS     += $(NOSTDINC_FLAGS)
 744
 745 # warn about C99 declaration after statement
 746 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
 747
 748 # disable pointer signed / unsigned warnings in gcc 4.0
 749 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
 750
 751 # disable invalid "can't wrap" optimizations for signed / pointers
 752 KBUILD_CFLAGS   += $(call cc-option,-fno-strict-overflow)
 753
 754 # conserve stack if available
 755 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
 756
 757 # disallow errors like 'EXPORT_GPL(foo);' with missing header
 758 KBUILD_CFLAGS   += $(call cc-option,-Werror=implicit-int)
 759
 760 # require functions to have arguments in prototypes, not empty 'int foo()'
 761 KBUILD_CFLAGS   += $(call cc-option,-Werror=strict-prototypes)
 762
 763 # Prohibit date/time macros, which would make the build non-deterministic
 764 KBUILD_CFLAGS   += $(call cc-option,-Werror=date-time)
 765
 766 # use the deterministic mode of AR if available
 767 KBUILD_ARFLAGS := $(call ar-option,D)
 768
 769 # check for 'asm goto'
 770 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
 771         KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
 772 endif
 773
 774 include $(srctree)/scripts/Makefile.extrawarn
 775
 776 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 777 KBUILD_CPPFLAGS += $(KCPPFLAGS)
 778 KBUILD_AFLAGS += $(KAFLAGS)
 779 KBUILD_CFLAGS += $(KCFLAGS)
 780
 781 # Use --build-id when available.
 782 LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
 783                               $(call cc-ldoption, -Wl$(comma)--build-id,))
 784 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
 785 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
 786
 787 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
 788 LDFLAGS_vmlinux += $(call ld-option, -X,)
 789 endif
 790
 791 # Default kernel image to build when no specific target is given.
 792 # KBUILD_IMAGE may be overruled on the command line or
 793 # set in the environment
 794 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
 795 # this default value
 796 export KBUILD_IMAGE ?= vmlinux
 797
 798 #
 799 # INSTALL_PATH specifies where to place the updated kernel and system map
 800 # images. Default is /boot, but you can set it to other values
 801 export  INSTALL_PATH ?= /boot
 802
 803 #
 804 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
 805 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
 806 # an argument if needed. Otherwise it defaults to the kernel install path
 807 #
 808 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
 809
 810 #
 811 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
 812 # relocations required by build roots.  This is not defined in the
 813 # makefile but the argument can be passed to make if needed.
 814 #
 815
 816 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
 817 export MODLIB
 818
 819 #
 820 # INSTALL_MOD_STRIP, if defined, will cause modules to be
 821 # stripped after they are installed.  If INSTALL_MOD_STRIP is '1', then
 822 # the default option --strip-debug will be used.  Otherwise,
 823 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
 824
 825 ifdef INSTALL_MOD_STRIP
 826 ifeq ($(INSTALL_MOD_STRIP),1)
 827 mod_strip_cmd = $(STRIP) --strip-debug
 828 else
 829 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
 830 endif # INSTALL_MOD_STRIP=1
 831 else
 832 mod_strip_cmd = true
 833 endif # INSTALL_MOD_STRIP
 834 export mod_strip_cmd
 835
 836 # Select initial ramdisk compression format, default is gzip(1).
 837 # This shall be used by the dracut(8) tool while creating an initramfs image.
 838 #
 839 INITRD_COMPRESS-y                  := gzip
 840 INITRD_COMPRESS-$(CONFIG_RD_BZIP2) := bzip2
 841 INITRD_COMPRESS-$(CONFIG_RD_LZMA)  := lzma
 842 INITRD_COMPRESS-$(CONFIG_RD_XZ)    := xz
 843 INITRD_COMPRESS-$(CONFIG_RD_LZO)   := lzo
 844 INITRD_COMPRESS-$(CONFIG_RD_LZ4)   := lz4
 845 # do not export INITRD_COMPRESS, since we didn't actually
 846 # choose a sane default compression above.
 847 # export INITRD_COMPRESS := $(INITRD_COMPRESS-y)
 848
 849 ifdef CONFIG_MODULE_SIG_ALL
 850 MODSECKEY = ./signing_key.priv
 851 MODPUBKEY = ./signing_key.x509
 852 export MODPUBKEY
 853 mod_sign_cmd = perl $(srctree)/scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODSECKEY) $(MODPUBKEY)
 854 else
 855 mod_sign_cmd = true
 856 endif
 857 export mod_sign_cmd
 858
 859
 860 ifeq ($(KBUILD_EXTMOD),)
 861 core-y          += kernel/ mm/ fs/ ipc/ security/ crypto/ block/
 862
 863 vmlinux-dirs    := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
 864                      $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
 865                      $(net-y) $(net-m) $(libs-y) $(libs-m)))
 866
 867 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
 868                      $(init-n) $(init-) \
 869                      $(core-n) $(core-) $(drivers-n) $(drivers-) \
 870                      $(net-n)  $(net-)  $(libs-n)    $(libs-))))
 871
 872 init-y          := $(patsubst %/, %/built-in.o, $(init-y))
 873 core-y          := $(patsubst %/, %/built-in.o, $(core-y))
 874 drivers-y       := $(patsubst %/, %/built-in.o, $(drivers-y))
 875 net-y           := $(patsubst %/, %/built-in.o, $(net-y))
 876 libs-y1         := $(patsubst %/, %/lib.a, $(libs-y))
 877 libs-y2         := $(patsubst %/, %/built-in.o, $(libs-y))
 878 libs-y          := $(libs-y1) $(libs-y2)
 879
 880 # Externally visible symbols (used by link-vmlinux.sh)
 881 export KBUILD_VMLINUX_INIT := $(head-y) $(init-y)
 882 export KBUILD_VMLINUX_MAIN := $(core-y) $(libs-y) $(drivers-y) $(net-y)
 883 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
 884 export LDFLAGS_vmlinux
 885 # used by scripts/pacmage/Makefile
 886 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools virt)
 887
 888 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_INIT) $(KBUILD_VMLINUX_MAIN)
 889
 890 # Final link of vmlinux
 891       cmd_link-vmlinux = $(CONFIG_SHELL) $< $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux)
 892 quiet_cmd_link-vmlinux = LINK    $@
 893
 894 # Include targets which we want to
 895 # execute if the rest of the kernel build went well.
 896 vmlinux: scripts/link-vmlinux.sh $(vmlinux-deps) FORCE
 897 ifdef CONFIG_HEADERS_CHECK
 898         $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
 899 endif
 900 ifdef CONFIG_SAMPLES
 901         $(Q)$(MAKE) $(build)=samples
 902 endif
 903 ifdef CONFIG_BUILD_DOCSRC
 904         $(Q)$(MAKE) $(build)=Documentation
 905 endif
 906         +$(call if_changed,link-vmlinux)
 907
 908 # The actual objects are generated when descending,
 909 # make sure no implicit rule kicks in
 910 $(sort $(vmlinux-deps)): $(vmlinux-dirs) ;
 911
 912 # Handle descending into subdirectories listed in $(vmlinux-dirs)
 913 # Preset locale variables to speed up the build process. Limit locale
 914 # tweaks to this spot to avoid wrong language settings when running
 915 # make menuconfig etc.
 916 # Error messages still appears in the original language
 917
 918 PHONY += $(vmlinux-dirs)
 919 $(vmlinux-dirs): prepare scripts
 920         $(Q)$(MAKE) $(build)=$@
 921
 922 define filechk_kernel.release
 923         echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
 924 endef
 925
 926 # Store (new) KERNELRELEASE string in include/config/kernel.release
 927 include/config/kernel.release: include/config/auto.conf FORCE
 928         $(call filechk,kernel.release)
 929
 930
 931 # Things we need to do before we recursively start building the kernel
 932 # or the modules are listed in "prepare".
 933 # A multi level approach is used. prepareN is processed before prepareN-1.
 934 # archprepare is used in arch Makefiles and when processed asm symlink,
 935 # version.h and scripts_basic is processed / created.
 936
 937 # Listed in dependency order
 938 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
 939
 940 # prepare3 is used to check if we are building in a separate output directory,
 941 # and if so do:
 942 # 1) Check that make has not been executed in the kernel src $(srctree)
 943 prepare3: include/config/kernel.release
 944 ifneq ($(KBUILD_SRC),)
 945         @$(kecho) '  Using $(srctree) as source for kernel'
 946         $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
 947                 echo >&2 "  $(srctree) is not clean, please run 'make mrproper'"; \
 948                 echo >&2 "  in the '$(srctree)' directory.";\
 949                 /bin/false; \
 950         fi;
 951 endif
 952
 953 # prepare2 creates a makefile if using a separate output directory
 954 prepare2: prepare3 outputmakefile asm-generic
 955
 956 prepare1: prepare2 $(version_h) include/generated/utsrelease.h \
 957                    include/config/auto.conf
 958         $(cmd_crmodverdir)
 959
 960 archprepare: archheaders archscripts prepare1 scripts_basic
 961
 962 prepare0: archprepare FORCE
 963         $(Q)$(MAKE) $(build)=.
 964
 965 # All the preparing..
 966 prepare: prepare0
 967
 968 # Generate some files
 969 # ---------------------------------------------------------------------------
 970
 971 # KERNELRELEASE can change from a few different places, meaning version.h
 972 # needs to be updated, so this check is forced on all builds
 973
 974 uts_len := 64
 975 define filechk_utsrelease.h
 976         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
 977           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
 978           exit 1;                                                         \
 979         fi;                                                               \
 980         (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
 981 endef
 982
 983 define filechk_version.h
 984         (echo \#define LINUX_VERSION_CODE $(shell                         \
 985         expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
 986         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
 987 endef
 988
 989 $(version_h): $(srctree)/Makefile FORCE
 990         $(call filechk,version.h)
 991
 992 include/generated/utsrelease.h: include/config/kernel.release FORCE
 993         $(call filechk,utsrelease.h)
 994
 995 PHONY += headerdep
 996 headerdep:
 997         $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
 998         $(srctree)/scripts/headerdep.pl -I$(srctree)/include
 999
1000 # ---------------------------------------------------------------------------
1001
1002 PHONY += depend dep
1003 depend dep:
1004         @echo '*** Warning: make $@ is unnecessary now.'
1005
1006 # ---------------------------------------------------------------------------
1007 # Firmware install
1008 INSTALL_FW_PATH=$(INSTALL_MOD_PATH)/lib/firmware
1009 export INSTALL_FW_PATH
1010
1011 PHONY += firmware_install
1012 firmware_install: FORCE
1013         @mkdir -p $(objtree)/firmware
1014         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_install
1015
1016 # ---------------------------------------------------------------------------
1017 # Kernel headers
1018
1019 #Default location for installed headers
1020 export INSTALL_HDR_PATH = $(objtree)/usr
1021
1022 hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
1023
1024 # If we do an all arch process set dst to asm-$(hdr-arch)
1025 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
1026
1027 PHONY += archheaders
1028 archheaders:
1029
1030 PHONY += archscripts
1031 archscripts:
1032
1033 PHONY += __headers
1034 __headers: $(version_h) scripts_basic asm-generic archheaders archscripts FORCE
1035         $(Q)$(MAKE) $(build)=scripts build_unifdef
1036
1037 PHONY += headers_install_all
1038 headers_install_all:
1039         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1040
1041 PHONY += headers_install
1042 headers_install: __headers
1043         $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/uapi/asm/Kbuild),, \
1044           $(error Headers not exportable for the $(SRCARCH) architecture))
1045         $(Q)$(MAKE) $(hdr-inst)=include/uapi
1046         $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi/asm $(hdr-dst)
1047
1048 PHONY += headers_check_all
1049 headers_check_all: headers_install_all
1050         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1051
1052 PHONY += headers_check
1053 headers_check: headers_install
1054         $(Q)$(MAKE) $(hdr-inst)=include/uapi HDRCHECK=1
1055         $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/uapi/asm $(hdr-dst) HDRCHECK=1
1056
1057 # ---------------------------------------------------------------------------
1058 # Modules
1059
1060 ifdef CONFIG_MODULES
1061
1062 # By default, build modules as well
1063
1064 all: modules
1065
1066 # Build modules
1067 #
1068 # A module can be listed more than once in obj-m resulting in
1069 # duplicate lines in modules.order files.  Those are removed
1070 # using awk while concatenating to the final file.
1071
1072 PHONY += modules
1073 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1074         $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1075         @$(kecho) '  Building modules, stage 2.';
1076         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1077         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modbuild
1078
1079 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1080         $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1081
1082 %/modules.builtin: include/config/auto.conf
1083         $(Q)$(MAKE) $(modbuiltin)=$*
1084
1085
1086 # Target to prepare building external modules
1087 PHONY += modules_prepare
1088 modules_prepare: prepare scripts
1089
1090 # Target to install modules
1091 PHONY += modules_install
1092 modules_install: _modinst_ _modinst_post
1093
1094 PHONY += _modinst_
1095 _modinst_:
1096         @rm -rf $(MODLIB)/kernel
1097         @rm -f $(MODLIB)/source
1098         @mkdir -p $(MODLIB)/kernel
1099         @ln -s `cd $(srctree) && /bin/pwd` $(MODLIB)/source
1100         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1101                 rm -f $(MODLIB)/build ; \
1102                 ln -s $(CURDIR) $(MODLIB)/build ; \
1103         fi
1104         @cp -f $(objtree)/modules.order $(MODLIB)/
1105         @cp -f $(objtree)/modules.builtin $(MODLIB)/
1106         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1107
1108 # This depmod is only for convenience to give the initial
1109 # boot a modules.dep even before / is mounted read-write.  However the
1110 # boot script depmod is the master version.
1111 PHONY += _modinst_post
1112 _modinst_post: _modinst_
1113         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modinst
1114         $(call cmd,depmod)
1115
1116 ifeq ($(CONFIG_MODULE_SIG), y)
1117 PHONY += modules_sign
1118 modules_sign:
1119         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1120 endif
1121
1122 else # CONFIG_MODULES
1123
1124 # Modules not configured
1125 # ---------------------------------------------------------------------------
1126
1127 modules modules_install: FORCE
1128         @echo >&2
1129         @echo >&2 "The present kernel configuration has modules disabled."
1130         @echo >&2 "Type 'make config' and enable loadable module support."
1131         @echo >&2 "Then build a kernel with module support enabled."
1132         @echo >&2
1133         @exit 1
1134
1135 endif # CONFIG_MODULES
1136
1137 ###
1138 # Cleaning is done on three levels.
1139 # make clean     Delete most generated files
1140 #                Leave enough to build external modules
1141 # make mrproper  Delete the current configuration, and all generated files
1142 # make distclean Remove editor backup files, patch leftover files and the like
1143
1144 # Directories & files removed with 'make clean'
1145 CLEAN_DIRS  += $(MODVERDIR)
1146
1147 # Directories & files removed with 'make mrproper'
1148 MRPROPER_DIRS  += include/config usr/include include/generated          \
1149                   arch/*/include/generated .tmp_objdiff
1150 MRPROPER_FILES += .config .config.old .version .old_version $(version_h) \
1151                   Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
1152                   signing_key.priv signing_key.x509 x509.genkey         \
1153                   extra_certificates signing_key.x509.keyid             \
1154                   signing_key.x509.signer include/linux/version.h
1155
1156 # clean - Delete most, but leave enough to build external modules
1157 #
1158 clean: rm-dirs  := $(CLEAN_DIRS)
1159 clean: rm-files := $(CLEAN_FILES)
1160 clean-dirs      := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
1161
1162 PHONY += $(clean-dirs) clean archclean vmlinuxclean
1163 $(clean-dirs):
1164         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1165
1166 vmlinuxclean:
1167         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1168
1169 clean: archclean vmlinuxclean
1170
1171 # mrproper - Delete all generated files, including .config
1172 #
1173 mrproper: rm-dirs  := $(wildcard $(MRPROPER_DIRS))
1174 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1175 mrproper-dirs      := $(addprefix _mrproper_,Documentation/DocBook scripts)
1176
1177 PHONY += $(mrproper-dirs) mrproper archmrproper
1178 $(mrproper-dirs):
1179         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1180
1181 mrproper: clean archmrproper $(mrproper-dirs)
1182         $(call cmd,rmdirs)
1183         $(call cmd,rmfiles)
1184
1185 # distclean
1186 #
1187 PHONY += distclean
1188
1189 distclean: mrproper
1190         @find $(srctree) $(RCS_FIND_IGNORE) \
1191                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1192                 -o -name '*.bak' -o -name '#*#' -o -name '.*.orig' \
1193                 -o -name '.*.rej' -o -name '*%'  -o -name 'core' \) \
1194                 -type f -print | xargs rm -f
1195
1196
1197 # Packaging of the kernel to various formats
1198 # ---------------------------------------------------------------------------
1199 # rpm target kept for backward compatibility
1200 package-dir     := scripts/package
1201
1202 %src-pkg: FORCE
1203         $(Q)$(MAKE) $(build)=$(package-dir) $@
1204 %pkg: include/config/kernel.release FORCE
1205         $(Q)$(MAKE) $(build)=$(package-dir) $@
1206 rpm: include/config/kernel.release FORCE
1207         $(Q)$(MAKE) $(build)=$(package-dir) $@
1208
1209
1210 # Brief documentation of the typical targets used
1211 # ---------------------------------------------------------------------------
1212
1213 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1214 boards := $(notdir $(boards))
1215 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1216 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1217
1218 help:
1219         @echo  'Cleaning targets:'
1220         @echo  '  clean           - Remove most generated files but keep the config and'
1221         @echo  '                    enough build support to build external modules'
1222         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1223         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1224         @echo  ''
1225         @echo  'Configuration targets:'
1226         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1227         @echo  ''
1228         @echo  'Other generic targets:'
1229         @echo  '  all             - Build all targets marked with [*]'
1230         @echo  '* vmlinux         - Build the bare kernel'
1231         @echo  '* modules         - Build all modules'
1232         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1233         @echo  '  firmware_install- Install all firmware to INSTALL_FW_PATH'
1234         @echo  '                    (default: $$(INSTALL_MOD_PATH)/lib/firmware)'
1235         @echo  '  dir/            - Build all files in dir and below'
1236         @echo  '  dir/file.[oisS] - Build specified target only'
1237         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1238         @echo  '                    (requires a recent binutils and recent build (System.map))'
1239         @echo  '  dir/file.ko     - Build module including final link'
1240         @echo  '  modules_prepare - Set up for building external modules'
1241         @echo  '  tags/TAGS       - Generate tags file for editors'
1242         @echo  '  cscope          - Generate cscope index'
1243         @echo  '  gtags           - Generate GNU GLOBAL index'
1244         @echo  '  kernelrelease   - Output the release version string'
1245         @echo  '  kernelversion   - Output the version stored in Makefile'
1246         @echo  '  image_name      - Output the image name'
1247         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1248          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1249          echo  ''
1250         @echo  'Static analysers'
1251         @echo  '  checkstack      - Generate a list of stack hogs'
1252         @echo  '  namespacecheck  - Name space analysis on compiled kernel'
1253         @echo  '  versioncheck    - Sanity check on version.h usage'
1254         @echo  '  includecheck    - Check for duplicate included header files'
1255         @echo  '  export_report   - List the usages of all exported symbols'
1256         @echo  '  headers_check   - Sanity check on exported headers'
1257         @echo  '  headerdep       - Detect inclusion cycles in headers'
1258         @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1259         @echo  ''
1260         @echo  'Kernel packaging:'
1261         @$(MAKE) $(build)=$(package-dir) help
1262         @echo  ''
1263         @echo  'Documentation targets:'
1264         @$(MAKE) -f $(srctree)/Documentation/DocBook/Makefile dochelp
1265         @echo  ''
1266         @echo  'Architecture specific targets ($(SRCARCH)):'
1267         @$(if $(archhelp),$(archhelp),\
1268                 echo '  No architecture specific help defined for $(SRCARCH)')
1269         @echo  ''
1270         @$(if $(boards), \
1271                 $(foreach b, $(boards), \
1272                 printf "  %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1273                 echo '')
1274         @$(if $(board-dirs), \
1275                 $(foreach b, $(board-dirs), \
1276                 printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1277                 printf "  %-16s - Show all of the above\\n" help-boards; \
1278                 echo '')
1279
1280         @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1281         @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1282         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1283         @echo  '  make C=1   [targets] Check all c source with $$CHECK (sparse by default)'
1284         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1285         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1286         @echo  '  make W=n   [targets] Enable extra gcc checks, n=1,2,3 where'
1287         @echo  '                1: warnings which may be relevant and do not occur too often'
1288         @echo  '                2: warnings which occur quite often but may still be relevant'
1289         @echo  '                3: more obscure warnings, can most likely be ignored'
1290         @echo  '                Multiple levels can be combined with W=12 or W=123'
1291         @echo  ''
1292         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1293         @echo  'For further info see the ./README file'
1294
1295
1296 help-board-dirs := $(addprefix help-,$(board-dirs))
1297
1298 help-boards: $(help-board-dirs)
1299
1300 boards-per-dir = $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig))
1301
1302 $(help-board-dirs): help-%:
1303         @echo  'Architecture specific targets ($(SRCARCH) $*):'
1304         @$(if $(boards-per-dir), \
1305                 $(foreach b, $(boards-per-dir), \
1306                 printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1307                 echo '')
1308
1309
1310 # Documentation targets
1311 # ---------------------------------------------------------------------------
1312 %docs: scripts_basic FORCE
1313         $(Q)$(MAKE) $(build)=scripts build_docproc
1314         $(Q)$(MAKE) $(build)=Documentation/DocBook $@
1315
1316 else # KBUILD_EXTMOD
1317
1318 ###
1319 # External module support.
1320 # When building external modules the kernel used as basis is considered
1321 # read-only, and no consistency checks are made and the make
1322 # system is not used on the basis kernel. If updates are required
1323 # in the basis kernel ordinary make commands (without M=...) must
1324 # be used.
1325 #
1326 # The following are the only valid targets when building external
1327 # modules.
1328 # make M=dir clean     Delete all automatically generated files
1329 # make M=dir modules   Make all modules in specified dir
1330 # make M=dir           Same as 'make M=dir modules'
1331 # make M=dir modules_install
1332 #                      Install the modules built in the module directory
1333 #                      Assumes install directory is already created
1334
1335 # We are always building modules
1336 KBUILD_MODULES := 1
1337 PHONY += crmodverdir
1338 crmodverdir:
1339         $(cmd_crmodverdir)
1340
1341 PHONY += $(objtree)/Module.symvers
1342 $(objtree)/Module.symvers:
1343         @test -e $(objtree)/Module.symvers || ( \
1344         echo; \
1345         echo "  WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1346         echo "           is missing; modules will have no dependencies and modversions."; \
1347         echo )
1348
1349 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1350 PHONY += $(module-dirs) modules
1351 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1352         $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1353
1354 modules: $(module-dirs)
1355         @$(kecho) '  Building modules, stage 2.';
1356         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1357
1358 PHONY += modules_install
1359 modules_install: _emodinst_ _emodinst_post
1360
1361 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1362 PHONY += _emodinst_
1363 _emodinst_:
1364         $(Q)mkdir -p $(MODLIB)/$(install-dir)
1365         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1366
1367 PHONY += _emodinst_post
1368 _emodinst_post: _emodinst_
1369         $(call cmd,depmod)
1370
1371 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1372
1373 PHONY += $(clean-dirs) clean
1374 $(clean-dirs):
1375         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1376
1377 clean:  rm-dirs := $(MODVERDIR)
1378 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1379
1380 help:
1381         @echo  '  Building external modules.'
1382         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1383         @echo  ''
1384         @echo  '  modules         - default target, build the module(s)'
1385         @echo  '  modules_install - install the module'
1386         @echo  '  clean           - remove generated files in module directory only'
1387         @echo  ''
1388
1389 # Dummies...
1390 PHONY += prepare scripts
1391 prepare: ;
1392 scripts: ;
1393 endif # KBUILD_EXTMOD
1394
1395 clean: $(clean-dirs)
1396         $(call cmd,rmdirs)
1397         $(call cmd,rmfiles)
1398         @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1399                 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1400                 -o -name '*.ko.*' \
1401                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1402                 -o -name '*.symtypes' -o -name 'modules.order' \
1403                 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1404                 -o -name '*.gcno' \) -type f -print | xargs rm -f
1405
1406 # Generate tags for editors
1407 # ---------------------------------------------------------------------------
1408 quiet_cmd_tags = GEN     $@
1409       cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1410
1411 tags TAGS cscope gtags: FORCE
1412         $(call cmd,tags)
1413
1414 # Scripts to check various things for consistency
1415 # ---------------------------------------------------------------------------
1416
1417 PHONY += includecheck versioncheck coccicheck namespacecheck export_report
1418
1419 includecheck:
1420         find $(srctree)/* $(RCS_FIND_IGNORE) \
1421                 -name '*.[hcS]' -type f -print | sort \
1422                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1423
1424 versioncheck:
1425         find $(srctree)/* $(RCS_FIND_IGNORE) \
1426                 -name '*.[hcS]' -type f -print | sort \
1427                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1428
1429 coccicheck:
1430         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1431
1432 namespacecheck:
1433         $(PERL) $(srctree)/scripts/namespace.pl
1434
1435 export_report:
1436         $(PERL) $(srctree)/scripts/export_report.pl
1437
1438 endif #ifeq ($(config-targets),1)
1439 endif #ifeq ($(mixed-targets),1)
1440
1441 PHONY += checkstack kernelrelease kernelversion image_name
1442
1443 # UML needs a little special treatment here.  It wants to use the host
1444 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1445 # else wants $(ARCH), including people doing cross-builds, which means
1446 # that $(SUBARCH) doesn't work here.
1447 ifeq ($(ARCH), um)
1448 CHECKSTACK_ARCH := $(SUBARCH)
1449 else
1450 CHECKSTACK_ARCH := $(ARCH)
1451 endif
1452 checkstack:
1453         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1454         $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1455
1456 kernelrelease:
1457         @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1458
1459 kernelversion:
1460         @echo $(KERNELVERSION)
1461
1462 image_name:
1463         @echo $(KBUILD_IMAGE)
1464
1465 # Clear a bunch of variables before executing the submake
1466 tools/: FORCE
1467         $(Q)mkdir -p $(objtree)/tools
1468         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(filter --j% -j,$(MAKEFLAGS))" O=$(objtree) subdir=tools -C $(src)/tools/
1469
1470 tools/%: FORCE
1471         $(Q)mkdir -p $(objtree)/tools
1472         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(filter --j% -j,$(MAKEFLAGS))" O=$(objtree) subdir=tools -C $(src)/tools/ $*
1473
1474 # Single targets
1475 # ---------------------------------------------------------------------------
1476 # Single targets are compatible with:
1477 # - build with mixed source and output
1478 # - build with separate output dir 'make O=...'
1479 # - external modules
1480 #
1481 #  target-dir => where to store outputfile
1482 #  build-dir  => directory in kernel source tree to use
1483
1484 ifeq ($(KBUILD_EXTMOD),)
1485         build-dir  = $(patsubst %/,%,$(dir $@))
1486         target-dir = $(dir $@)
1487 else
1488         zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1489         build-dir  = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1490         target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1491 endif
1492
1493 %.s: %.c prepare scripts FORCE
1494         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1495 %.i: %.c prepare scripts FORCE
1496         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1497 %.o: %.c prepare scripts FORCE
1498         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1499 %.lst: %.c prepare scripts FORCE
1500         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1501 %.s: %.S prepare scripts FORCE
1502         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1503 %.o: %.S prepare scripts FORCE
1504         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1505 %.symtypes: %.c prepare scripts FORCE
1506         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1507
1508 # Modules
1509 /: prepare scripts FORCE
1510         $(cmd_crmodverdir)
1511         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1512         $(build)=$(build-dir)
1513 %/: prepare scripts FORCE
1514         $(cmd_crmodverdir)
1515         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1516         $(build)=$(build-dir)
1517 %.ko: prepare scripts FORCE
1518         $(cmd_crmodverdir)
1519         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)   \
1520         $(build)=$(build-dir) $(@:.ko=.o)
1521         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1522
1523 # FIXME Should go into a make.lib or something
1524 # ===========================================================================
1525
1526 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN   $(wildcard $(rm-dirs)))
1527       cmd_rmdirs = rm -rf $(rm-dirs)
1528
1529 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1530       cmd_rmfiles = rm -f $(rm-files)
1531
1532 # Run depmod only if we have System.map and depmod is executable
1533 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
1534       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1535                    $(KERNELRELEASE) "$(patsubst y,_,$(CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX))"
1536
1537 # Create temporary dir for module support files
1538 # clean it up only when building all modules
1539 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1540                   $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1541
1542 # read all saved command lines
1543
1544 targets := $(wildcard $(sort $(targets)))
1545 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1546
1547 ifneq ($(cmd_files),)
1548   $(cmd_files): ;       # Do not try to update included dependency files
1549   include $(cmd_files)
1550 endif
1551
1552 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=dir
1553 # Usage:
1554 # $(Q)$(MAKE) $(clean)=dir
1555 clean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean obj
1556
1557 endif   # skip-makefile
1558
1559 PHONY += FORCE
1560 FORCE:
1561
1562 # Declare the contents of the .PHONY variable as phony.  We keep that
1563 # information in a variable so we can use it in if_changed and friends.
1564 .PHONY: $(PHONY)