Makefile

   1 VERSION = 2
   2 PATCHLEVEL = 6
   3 SUBLEVEL = 25
   4 EXTRAVERSION =
   5 NAME = Funky Weasel is Jiggy wit it
   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 # We are using a recursive build, so we need to do a little thinking
  20 # to get the ordering right.
  21 #
  22 # Most importantly: sub-Makefiles should only ever modify files in
  23 # their own directory. If in some directory we have a dependency on
  24 # a file in another dir (which doesn't happen often, but it's often
  25 # unavoidable when linking the built-in.o targets which finally
  26 # turn into vmlinux), we will call a sub make in that other dir, and
  27 # after that we are sure that everything which is in that other dir
  28 # is now up to date.
  29 #
  30 # The only cases where we need to modify files which have global
  31 # effects are thus separated out and done before the recursive
  32 # descending is started. They are now explicitly listed as the
  33 # prepare rule.
  34
  35 # To put more focus on warnings, be less verbose as default
  36 # Use 'make V=1' to see the full commands
  37
  38 ifdef V
  39   ifeq ("$(origin V)", "command line")
  40     KBUILD_VERBOSE = $(V)
  41   endif
  42 endif
  43 ifndef KBUILD_VERBOSE
  44   KBUILD_VERBOSE = 0
  45 endif
  46
  47 # Call a source code checker (by default, "sparse") as part of the
  48 # C compilation.
  49 #
  50 # Use 'make C=1' to enable checking of only re-compiled files.
  51 # Use 'make C=2' to enable checking of *all* source files, regardless
  52 # of whether they are re-compiled or not.
  53 #
  54 # See the file "Documentation/sparse.txt" for more details, including
  55 # where to get the "sparse" utility.
  56
  57 ifdef C
  58   ifeq ("$(origin C)", "command line")
  59     KBUILD_CHECKSRC = $(C)
  60   endif
  61 endif
  62 ifndef KBUILD_CHECKSRC
  63   KBUILD_CHECKSRC = 0
  64 endif
  65
  66 # Use make M=dir to specify directory of external module to build
  67 # Old syntax make ... SUBDIRS=$PWD is still supported
  68 # Setting the environment variable KBUILD_EXTMOD take precedence
  69 ifdef SUBDIRS
  70   KBUILD_EXTMOD ?= $(SUBDIRS)
  71 endif
  72 ifdef M
  73   ifeq ("$(origin M)", "command line")
  74     KBUILD_EXTMOD := $(M)
  75   endif
  76 endif
  77
  78
  79 # kbuild supports saving output files in a separate directory.
  80 # To locate output files in a separate directory two syntaxes are supported.
  81 # In both cases the working directory must be the root of the kernel src.
  82 # 1) O=
  83 # Use "make O=dir/to/store/output/files/"
  84 #
  85 # 2) Set KBUILD_OUTPUT
  86 # Set the environment variable KBUILD_OUTPUT to point to the directory
  87 # where the output files shall be placed.
  88 # export KBUILD_OUTPUT=dir/to/store/output/files/
  89 # make
  90 #
  91 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
  92 # variable.
  93
  94
  95 # KBUILD_SRC is set on invocation of make in OBJ directory
  96 # KBUILD_SRC is not intended to be used by the regular user (for now)
  97 ifeq ($(KBUILD_SRC),)
  98
  99 # OK, Make called in directory where kernel src resides
 100 # Do we want to locate output files in a separate directory?
 101 ifdef O
 102   ifeq ("$(origin O)", "command line")
 103     KBUILD_OUTPUT := $(O)
 104   endif
 105 endif
 106
 107 # That's our default target when none is given on the command line
 108 PHONY := _all
 109 _all:
 110
 111 # Cancel implicit rules on top Makefile
 112 $(CURDIR)/Makefile Makefile: ;
 113
 114 ifneq ($(KBUILD_OUTPUT),)
 115 # Invoke a second make in the output directory, passing relevant variables
 116 # check that the output directory actually exists
 117 saved-output := $(KBUILD_OUTPUT)
 118 KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)
 119 $(if $(KBUILD_OUTPUT),, \
 120      $(error output directory "$(saved-output)" does not exist))
 121
 122 PHONY += $(MAKECMDGOALS) sub-make
 123
 124 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
 125         $(Q)@:
 126
 127 sub-make: FORCE
 128         $(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT) \
 129         KBUILD_SRC=$(CURDIR) \
 130         KBUILD_EXTMOD="$(KBUILD_EXTMOD)" -f $(CURDIR)/Makefile \
 131         $(filter-out _all sub-make,$(MAKECMDGOALS))
 132
 133 # Leave processing to above invocation of make
 134 skip-makefile := 1
 135 endif # ifneq ($(KBUILD_OUTPUT),)
 136 endif # ifeq ($(KBUILD_SRC),)
 137
 138 # We process the rest of the Makefile if this is the final invocation of make
 139 ifeq ($(skip-makefile),)
 140
 141 # If building an external module we do not care about the all: rule
 142 # but instead _all depend on modules
 143 PHONY += all
 144 ifeq ($(KBUILD_EXTMOD),)
 145 _all: all
 146 else
 147 _all: modules
 148 endif
 149
 150 srctree         := $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR))
 151 TOPDIR          := $(srctree)
 152 # FIXME - TOPDIR is obsolete, use srctree/objtree
 153 objtree         := $(CURDIR)
 154 src             := $(srctree)
 155 obj             := $(objtree)
 156
 157 VPATH           := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
 158
 159 export srctree objtree VPATH TOPDIR
 160
 161
 162 # SUBARCH tells the usermode build what the underlying arch is.  That is set
 163 # first, and if a usermode build is happening, the "ARCH=um" on the command
 164 # line overrides the setting of ARCH below.  If a native build is happening,
 165 # then ARCH is assigned, getting whatever value it gets normally, and
 166 # SUBARCH is subsequently ignored.
 167
 168 SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
 169                                   -e s/arm.*/arm/ -e s/sa110/arm/ \
 170                                   -e s/s390x/s390/ -e s/parisc64/parisc/ \
 171                                   -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
 172                                   -e s/sh.*/sh/ )
 173
 174 # Cross compiling and selecting different set of gcc/bin-utils
 175 # ---------------------------------------------------------------------------
 176 #
 177 # When performing cross compilation for other architectures ARCH shall be set
 178 # to the target architecture. (See arch/* for the possibilities).
 179 # ARCH can be set during invocation of make:
 180 # make ARCH=ia64
 181 # Another way is to have ARCH set in the environment.
 182 # The default ARCH is the host where make is executed.
 183
 184 # CROSS_COMPILE specify the prefix used for all executables used
 185 # during compilation. Only gcc and related bin-utils executables
 186 # are prefixed with $(CROSS_COMPILE).
 187 # CROSS_COMPILE can be set on the command line
 188 # make CROSS_COMPILE=ia64-linux-
 189 # Alternatively CROSS_COMPILE can be set in the environment.
 190 # Default value for CROSS_COMPILE is not to prefix executables
 191 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 192 export KBUILD_BUILDHOST := $(SUBARCH)
 193 ARCH            ?= $(SUBARCH)
 194 CROSS_COMPILE   ?=
 195
 196 # Architecture as present in compile.h
 197 UTS_MACHINE     := $(ARCH)
 198 SRCARCH         := $(ARCH)
 199
 200 # Additional ARCH settings for x86
 201 ifeq ($(ARCH),i386)
 202         SRCARCH := x86
 203 endif
 204 ifeq ($(ARCH),x86_64)
 205         SRCARCH := x86
 206 endif
 207
 208 KCONFIG_CONFIG  ?= .config
 209
 210 # SHELL used by kbuild
 211 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 212           else if [ -x /bin/bash ]; then echo /bin/bash; \
 213           else echo sh; fi ; fi)
 214
 215 HOSTCC       = gcc
 216 HOSTCXX      = g++
 217 HOSTCFLAGS   = -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer
 218 HOSTCXXFLAGS = -O2
 219
 220 # Decide whether to build built-in, modular, or both.
 221 # Normally, just do built-in.
 222
 223 KBUILD_MODULES :=
 224 KBUILD_BUILTIN := 1
 225
 226 #       If we have only "make modules", don't compile built-in objects.
 227 #       When we're building modules with modversions, we need to consider
 228 #       the built-in objects during the descend as well, in order to
 229 #       make sure the checksums are up to date before we record them.
 230
 231 ifeq ($(MAKECMDGOALS),modules)
 232   KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
 233 endif
 234
 235 #       If we have "make <whatever> modules", compile modules
 236 #       in addition to whatever we do anyway.
 237 #       Just "make" or "make all" shall build modules as well
 238
 239 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
 240   KBUILD_MODULES := 1
 241 endif
 242
 243 ifeq ($(MAKECMDGOALS),)
 244   KBUILD_MODULES := 1
 245 endif
 246
 247 export KBUILD_MODULES KBUILD_BUILTIN
 248 export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
 249
 250 # Beautify output
 251 # ---------------------------------------------------------------------------
 252 #
 253 # Normally, we echo the whole command before executing it. By making
 254 # that echo $($(quiet)$(cmd)), we now have the possibility to set
 255 # $(quiet) to choose other forms of output instead, e.g.
 256 #
 257 #         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
 258 #         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
 259 #
 260 # If $(quiet) is empty, the whole command will be printed.
 261 # If it is set to "quiet_", only the short version will be printed.
 262 # If it is set to "silent_", nothing will be printed at all, since
 263 # the variable $(silent_cmd_cc_o_c) doesn't exist.
 264 #
 265 # A simple variant is to prefix commands with $(Q) - that's useful
 266 # for commands that shall be hidden in non-verbose mode.
 267 #
 268 #       $(Q)ln $@ :<
 269 #
 270 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
 271 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
 272
 273 ifeq ($(KBUILD_VERBOSE),1)
 274   quiet =
 275   Q =
 276 else
 277   quiet=quiet_
 278   Q = @
 279 endif
 280
 281 # If the user is running make -s (silent mode), suppress echoing of
 282 # commands
 283
 284 ifneq ($(findstring s,$(MAKEFLAGS)),)
 285   quiet=silent_
 286 endif
 287
 288 export quiet Q KBUILD_VERBOSE
 289
 290
 291 # Look for make include files relative to root of kernel src
 292 MAKEFLAGS += --include-dir=$(srctree)
 293
 294 # We need some generic definitions (do not try to remake the file).
 295 $(srctree)/scripts/Kbuild.include: ;
 296 include $(srctree)/scripts/Kbuild.include
 297
 298 # Make variables (CC, etc...)
 299
 300 AS              = $(CROSS_COMPILE)as
 301 LD              = $(CROSS_COMPILE)ld
 302 CC              = $(CROSS_COMPILE)gcc
 303 CPP             = $(CC) -E
 304 AR              = $(CROSS_COMPILE)ar
 305 NM              = $(CROSS_COMPILE)nm
 306 STRIP           = $(CROSS_COMPILE)strip
 307 OBJCOPY         = $(CROSS_COMPILE)objcopy
 308 OBJDUMP         = $(CROSS_COMPILE)objdump
 309 AWK             = awk
 310 GENKSYMS        = scripts/genksyms/genksyms
 311 DEPMOD          = /sbin/depmod
 312 KALLSYMS        = scripts/kallsyms
 313 PERL            = perl
 314 CHECK           = sparse
 315
 316 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ -Wbitwise $(CF)
 317 MODFLAGS        = -DMODULE
 318 CFLAGS_MODULE   = $(MODFLAGS)
 319 AFLAGS_MODULE   = $(MODFLAGS)
 320 LDFLAGS_MODULE  =
 321 CFLAGS_KERNEL   =
 322 AFLAGS_KERNEL   =
 323
 324
 325 # Use LINUXINCLUDE when you must reference the include/ directory.
 326 # Needed to be compatible with the O= option
 327 LINUXINCLUDE    := -Iinclude \
 328                    $(if $(KBUILD_SRC),-Iinclude2 -I$(srctree)/include) \
 329                    -include include/linux/autoconf.h
 330
 331 KBUILD_CPPFLAGS := -D__KERNEL__ $(LINUXINCLUDE)
 332
 333 KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 334                    -fno-strict-aliasing -fno-common \
 335                    -Werror-implicit-function-declaration
 336 KBUILD_AFLAGS   := -D__ASSEMBLY__
 337
 338 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 339 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 340 KERNELVERSION = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
 341
 342 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 343 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
 344 export CPP AR NM STRIP OBJCOPY OBJDUMP MAKE AWK GENKSYMS PERL UTS_MACHINE
 345 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
 346
 347 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
 348 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 349 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 350
 351 # When compiling out-of-tree modules, put MODVERDIR in the module
 352 # tree rather than in the kernel tree. The kernel tree might
 353 # even be read-only.
 354 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
 355
 356 # Files to ignore in find ... statements
 357
 358 RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS -o -name .pc -o -name .hg -o -name .git \) -prune -o
 359 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn --exclude CVS --exclude .pc --exclude .hg --exclude .git
 360
 361 # ===========================================================================
 362 # Rules shared between *config targets and build targets
 363
 364 # Basic helpers built in scripts/
 365 PHONY += scripts_basic
 366 scripts_basic:
 367         $(Q)$(MAKE) $(build)=scripts/basic
 368
 369 # To avoid any implicit rule to kick in, define an empty command.
 370 scripts/basic/%: scripts_basic ;
 371
 372 PHONY += outputmakefile
 373 # outputmakefile generates a Makefile in the output directory, if using a
 374 # separate output directory. This allows convenient use of make in the
 375 # output directory.
 376 outputmakefile:
 377 ifneq ($(KBUILD_SRC),)
 378         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
 379             $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
 380 endif
 381
 382 # To make sure we do not include .config for any of the *config targets
 383 # catch them early, and hand them over to scripts/kconfig/Makefile
 384 # It is allowed to specify more targets when calling make, including
 385 # mixing *config targets and build targets.
 386 # For example 'make oldconfig all'.
 387 # Detect when mixed targets is specified, and make a second invocation
 388 # of make so .config is not included in this case either (for *config).
 389
 390 no-dot-config-targets := clean mrproper distclean \
 391                          cscope TAGS tags help %docs check% \
 392                          include/linux/version.h headers_% \
 393                          kernelrelease kernelversion
 394
 395 config-targets := 0
 396 mixed-targets  := 0
 397 dot-config     := 1
 398
 399 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 400         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 401                 dot-config := 0
 402         endif
 403 endif
 404
 405 ifeq ($(KBUILD_EXTMOD),)
 406         ifneq ($(filter config %config,$(MAKECMDGOALS)),)
 407                 config-targets := 1
 408                 ifneq ($(filter-out config %config,$(MAKECMDGOALS)),)
 409                         mixed-targets := 1
 410                 endif
 411         endif
 412 endif
 413
 414 ifeq ($(mixed-targets),1)
 415 # ===========================================================================
 416 # We're called with mixed targets (*config and build targets).
 417 # Handle them one by one.
 418
 419 %:: FORCE
 420         $(Q)$(MAKE) -C $(srctree) KBUILD_SRC= $@
 421
 422 else
 423 ifeq ($(config-targets),1)
 424 # ===========================================================================
 425 # *config targets only - make sure prerequisites are updated, and descend
 426 # in scripts/kconfig to make the *config target
 427
 428 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 429 # KBUILD_DEFCONFIG may point out an alternative default configuration
 430 # used for 'make defconfig'
 431 include $(srctree)/arch/$(SRCARCH)/Makefile
 432 export KBUILD_DEFCONFIG
 433
 434 config %config: scripts_basic outputmakefile FORCE
 435         $(Q)mkdir -p include/linux include/config
 436         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 437
 438 else
 439 # ===========================================================================
 440 # Build targets only - this includes vmlinux, arch specific targets, clean
 441 # targets and others. In general all targets except *config targets.
 442
 443 ifeq ($(KBUILD_EXTMOD),)
 444 # Additional helpers built in scripts/
 445 # Carefully list dependencies so we do not try to build scripts twice
 446 # in parallel
 447 PHONY += scripts
 448 scripts: scripts_basic include/config/auto.conf
 449         $(Q)$(MAKE) $(build)=$(@)
 450
 451 # Objects we will link into vmlinux / subdirs we need to visit
 452 init-y          := init/
 453 drivers-y       := drivers/ sound/
 454 net-y           := net/
 455 libs-y          := lib/
 456 core-y          := usr/
 457 endif # KBUILD_EXTMOD
 458
 459 ifeq ($(dot-config),1)
 460 # Read in config
 461 -include include/config/auto.conf
 462
 463 ifeq ($(KBUILD_EXTMOD),)
 464 # Read in dependencies to all Kconfig* files, make sure to run
 465 # oldconfig if changes are detected.
 466 -include include/config/auto.conf.cmd
 467
 468 # To avoid any implicit rule to kick in, define an empty command
 469 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
 470
 471 # If .config is newer than include/config/auto.conf, someone tinkered
 472 # with it and forgot to run make oldconfig.
 473 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
 474 # we execute the config step to be sure to catch updated Kconfig files
 475 include/config/auto.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
 476         $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
 477 else
 478 # external modules needs include/linux/autoconf.h and include/config/auto.conf
 479 # but do not care if they are up-to-date. Use auto.conf to trigger the test
 480 PHONY += include/config/auto.conf
 481
 482 include/config/auto.conf:
 483         $(Q)test -e include/linux/autoconf.h -a -e $@ || (              \
 484         echo;                                                           \
 485         echo "  ERROR: Kernel configuration is invalid.";               \
 486         echo "         include/linux/autoconf.h or $@ are missing.";    \
 487         echo "         Run 'make oldconfig && make prepare' on kernel src to fix it.";  \
 488         echo;                                                           \
 489         /bin/false)
 490
 491 endif # KBUILD_EXTMOD
 492
 493 else
 494 # Dummy target needed, because used as prerequisite
 495 include/config/auto.conf: ;
 496 endif # $(dot-config)
 497
 498 # The all: target is the default when no target is given on the
 499 # command line.
 500 # This allow a user to issue only 'make' to build a kernel including modules
 501 # Defaults vmlinux but it is usually overridden in the arch makefile
 502 all: vmlinux
 503
 504 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 505 KBUILD_CFLAGS   += -Os
 506 else
 507 KBUILD_CFLAGS   += -O2
 508 endif
 509
 510 # Force gcc to behave correct even for buggy distributions
 511 # Arch Makefiles may override this setting
 512 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
 513
 514 include $(srctree)/arch/$(SRCARCH)/Makefile
 515
 516 ifdef CONFIG_FRAME_POINTER
 517 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 518 else
 519 KBUILD_CFLAGS   += -fomit-frame-pointer
 520 endif
 521
 522 ifdef CONFIG_DEBUG_INFO
 523 KBUILD_CFLAGS   += -g
 524 KBUILD_AFLAGS   += -gdwarf-2
 525 endif
 526
 527 # We trigger additional mismatches with less inlining
 528 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 529 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 530 endif
 531
 532 # arch Makefile may override CC so keep this after arch Makefile is included
 533 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 534 CHECKFLAGS     += $(NOSTDINC_FLAGS)
 535
 536 # warn about C99 declaration after statement
 537 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
 538
 539 # disable pointer signed / unsigned warnings in gcc 4.0
 540 KBUILD_CFLAGS += $(call cc-option,-Wno-pointer-sign,)
 541
 542 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 543 # But warn user when we do so
 544 warn-assign = \
 545 $(warning "WARNING: Appending $$K$(1) ($(K$(1))) from $(origin K$(1)) to kernel $$$(1)")
 546
 547 ifneq ($(KCPPFLAGS),)
 548         $(call warn-assign,CPPFLAGS)
 549         KBUILD_CPPFLAGS += $(KCPPFLAGS)
 550 endif
 551 ifneq ($(KAFLAGS),)
 552         $(call warn-assign,AFLAGS)
 553         KBUILD_AFLAGS += $(KAFLAGS)
 554 endif
 555 ifneq ($(KCFLAGS),)
 556         $(call warn-assign,CFLAGS)
 557         KBUILD_CFLAGS += $(KCFLAGS)
 558 endif
 559
 560 # Use --build-id when available.
 561 LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
 562                               $(call ld-option, -Wl$(comma)--build-id,))
 563 LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
 564 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
 565
 566 # Default kernel image to build when no specific target is given.
 567 # KBUILD_IMAGE may be overruled on the command line or
 568 # set in the environment
 569 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
 570 # this default value
 571 export KBUILD_IMAGE ?= vmlinux
 572
 573 #
 574 # INSTALL_PATH specifies where to place the updated kernel and system map
 575 # images. Default is /boot, but you can set it to other values
 576 export  INSTALL_PATH ?= /boot
 577
 578 #
 579 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
 580 # relocations required by build roots.  This is not defined in the
 581 # makefile but the argument can be passed to make if needed.
 582 #
 583
 584 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
 585 export MODLIB
 586
 587 #
 588 #  INSTALL_MOD_STRIP, if defined, will cause modules to be
 589 #  stripped after they are installed.  If INSTALL_MOD_STRIP is '1', then
 590 #  the default option --strip-debug will be used.  Otherwise,
 591 #  INSTALL_MOD_STRIP will used as the options to the strip command.
 592
 593 ifdef INSTALL_MOD_STRIP
 594 ifeq ($(INSTALL_MOD_STRIP),1)
 595 mod_strip_cmd = $(STRIP) --strip-debug
 596 else
 597 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
 598 endif # INSTALL_MOD_STRIP=1
 599 else
 600 mod_strip_cmd = true
 601 endif # INSTALL_MOD_STRIP
 602 export mod_strip_cmd
 603
 604
 605 ifeq ($(KBUILD_EXTMOD),)
 606 core-y          += kernel/ mm/ fs/ ipc/ security/ crypto/ block/
 607
 608 vmlinux-dirs    := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
 609                      $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
 610                      $(net-y) $(net-m) $(libs-y) $(libs-m)))
 611
 612 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
 613                      $(init-n) $(init-) \
 614                      $(core-n) $(core-) $(drivers-n) $(drivers-) \
 615                      $(net-n)  $(net-)  $(libs-n)    $(libs-))))
 616
 617 init-y          := $(patsubst %/, %/built-in.o, $(init-y))
 618 core-y          := $(patsubst %/, %/built-in.o, $(core-y))
 619 drivers-y       := $(patsubst %/, %/built-in.o, $(drivers-y))
 620 net-y           := $(patsubst %/, %/built-in.o, $(net-y))
 621 libs-y1         := $(patsubst %/, %/lib.a, $(libs-y))
 622 libs-y2         := $(patsubst %/, %/built-in.o, $(libs-y))
 623 libs-y          := $(libs-y1) $(libs-y2)
 624
 625 # Build vmlinux
 626 # ---------------------------------------------------------------------------
 627 # vmlinux is built from the objects selected by $(vmlinux-init) and
 628 # $(vmlinux-main). Most are built-in.o files from top-level directories
 629 # in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
 630 # Ordering when linking is important, and $(vmlinux-init) must be first.
 631 #
 632 # vmlinux
 633 #   ^
 634 #   |
 635 #   +-< $(vmlinux-init)
 636 #   |   +--< init/version.o + more
 637 #   |
 638 #   +--< $(vmlinux-main)
 639 #   |    +--< driver/built-in.o mm/built-in.o + more
 640 #   |
 641 #   +-< kallsyms.o (see description in CONFIG_KALLSYMS section)
 642 #
 643 # vmlinux version (uname -v) cannot be updated during normal
 644 # descending-into-subdirs phase since we do not yet know if we need to
 645 # update vmlinux.
 646 # Therefore this step is delayed until just before final link of vmlinux -
 647 # except in the kallsyms case where it is done just before adding the
 648 # symbols to the kernel.
 649 #
 650 # System.map is generated to document addresses of all kernel symbols
 651
 652 vmlinux-init := $(head-y) $(init-y)
 653 vmlinux-main := $(core-y) $(libs-y) $(drivers-y) $(net-y)
 654 vmlinux-all  := $(vmlinux-init) $(vmlinux-main)
 655 vmlinux-lds  := arch/$(SRCARCH)/kernel/vmlinux.lds
 656 export KBUILD_VMLINUX_OBJS := $(vmlinux-all)
 657
 658 # Rule to link vmlinux - also used during CONFIG_KALLSYMS
 659 # May be overridden by arch/$(ARCH)/Makefile
 660 quiet_cmd_vmlinux__ ?= LD      $@
 661       cmd_vmlinux__ ?= $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) -o $@ \
 662       -T $(vmlinux-lds) $(vmlinux-init)                          \
 663       --start-group $(vmlinux-main) --end-group                  \
 664       $(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o FORCE ,$^)
 665
 666 # Generate new vmlinux version
 667 quiet_cmd_vmlinux_version = GEN     .version
 668       cmd_vmlinux_version = set -e;                     \
 669         if [ ! -r .version ]; then                      \
 670           rm -f .version;                               \
 671           echo 1 >.version;                             \
 672         else                                            \
 673           mv .version .old_version;                     \
 674           expr 0$$(cat .old_version) + 1 >.version;     \
 675         fi;                                             \
 676         $(MAKE) $(build)=init
 677
 678 # Generate System.map
 679 quiet_cmd_sysmap = SYSMAP
 680       cmd_sysmap = $(CONFIG_SHELL) $(srctree)/scripts/mksysmap
 681
 682 # Link of vmlinux
 683 # If CONFIG_KALLSYMS is set .version is already updated
 684 # Generate System.map and verify that the content is consistent
 685 # Use + in front of the vmlinux_version rule to silent warning with make -j2
 686 # First command is ':' to allow us to use + in front of the rule
 687 define rule_vmlinux__
 688         :
 689         $(if $(CONFIG_KALLSYMS),,+$(call cmd,vmlinux_version))
 690
 691         $(call cmd,vmlinux__)
 692         $(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
 693
 694         $(Q)$(if $($(quiet)cmd_sysmap),                                      \
 695           echo '  $($(quiet)cmd_sysmap)  System.map' &&)                     \
 696         $(cmd_sysmap) $@ System.map;                                         \
 697         if [ $$? -ne 0 ]; then                                               \
 698                 rm -f $@;                                                    \
 699                 /bin/false;                                                  \
 700         fi;
 701         $(verify_kallsyms)
 702 endef
 703
 704
 705 ifdef CONFIG_KALLSYMS
 706 # Generate section listing all symbols and add it into vmlinux $(kallsyms.o)
 707 # It's a three stage process:
 708 # o .tmp_vmlinux1 has all symbols and sections, but __kallsyms is
 709 #   empty
 710 #   Running kallsyms on that gives us .tmp_kallsyms1.o with
 711 #   the right size - vmlinux version (uname -v) is updated during this step
 712 # o .tmp_vmlinux2 now has a __kallsyms section of the right size,
 713 #   but due to the added section, some addresses have shifted.
 714 #   From here, we generate a correct .tmp_kallsyms2.o
 715 # o The correct .tmp_kallsyms2.o is linked into the final vmlinux.
 716 # o Verify that the System.map from vmlinux matches the map from
 717 #   .tmp_vmlinux2, just in case we did not generate kallsyms correctly.
 718 # o If CONFIG_KALLSYMS_EXTRA_PASS is set, do an extra pass using
 719 #   .tmp_vmlinux3 and .tmp_kallsyms3.o.  This is only meant as a
 720 #   temporary bypass to allow the kernel to be built while the
 721 #   maintainers work out what went wrong with kallsyms.
 722
 723 ifdef CONFIG_KALLSYMS_EXTRA_PASS
 724 last_kallsyms := 3
 725 else
 726 last_kallsyms := 2
 727 endif
 728
 729 kallsyms.o := .tmp_kallsyms$(last_kallsyms).o
 730
 731 define verify_kallsyms
 732         $(Q)$(if $($(quiet)cmd_sysmap),                                      \
 733           echo '  $($(quiet)cmd_sysmap)  .tmp_System.map' &&)                \
 734           $(cmd_sysmap) .tmp_vmlinux$(last_kallsyms) .tmp_System.map
 735         $(Q)cmp -s System.map .tmp_System.map ||                             \
 736                 (echo Inconsistent kallsyms data;                            \
 737                  echo Try setting CONFIG_KALLSYMS_EXTRA_PASS;                \
 738                  rm .tmp_kallsyms* ; /bin/false )
 739 endef
 740
 741 # Update vmlinux version before link
 742 # Use + in front of this rule to silent warning about make -j1
 743 # First command is ':' to allow us to use + in front of this rule
 744 cmd_ksym_ld = $(cmd_vmlinux__)
 745 define rule_ksym_ld
 746         :
 747         +$(call cmd,vmlinux_version)
 748         $(call cmd,vmlinux__)
 749         $(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
 750 endef
 751
 752 # Generate .S file with all kernel symbols
 753 quiet_cmd_kallsyms = KSYM    $@
 754       cmd_kallsyms = $(NM) -n $< | $(KALLSYMS) \
 755                      $(if $(CONFIG_KALLSYMS_ALL),--all-symbols) > $@
 756
 757 .tmp_kallsyms1.o .tmp_kallsyms2.o .tmp_kallsyms3.o: %.o: %.S scripts FORCE
 758         $(call if_changed_dep,as_o_S)
 759
 760 .tmp_kallsyms%.S: .tmp_vmlinux% $(KALLSYMS)
 761         $(call cmd,kallsyms)
 762
 763 # .tmp_vmlinux1 must be complete except kallsyms, so update vmlinux version
 764 .tmp_vmlinux1: $(vmlinux-lds) $(vmlinux-all) FORCE
 765         $(call if_changed_rule,ksym_ld)
 766
 767 .tmp_vmlinux2: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms1.o FORCE
 768         $(call if_changed,vmlinux__)
 769
 770 .tmp_vmlinux3: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms2.o FORCE
 771         $(call if_changed,vmlinux__)
 772
 773 # Needs to visit scripts/ before $(KALLSYMS) can be used.
 774 $(KALLSYMS): scripts ;
 775
 776 # Generate some data for debugging strange kallsyms problems
 777 debug_kallsyms: .tmp_map$(last_kallsyms)
 778
 779 .tmp_map%: .tmp_vmlinux% FORCE
 780         ($(OBJDUMP) -h $< | $(AWK) '/^ +[0-9]/{print $$4 " 0 " $$2}'; $(NM) $<) | sort > $@
 781
 782 .tmp_map3: .tmp_map2
 783
 784 .tmp_map2: .tmp_map1
 785
 786 endif # ifdef CONFIG_KALLSYMS
 787
 788 # Do modpost on a prelinked vmlinux. The finally linked vmlinux has
 789 # relevant sections renamed as per the linker script.
 790 quiet_cmd_vmlinux-modpost = LD      $@
 791       cmd_vmlinux-modpost = $(LD) $(LDFLAGS) -r -o $@                          \
 792          $(vmlinux-init) --start-group $(vmlinux-main) --end-group             \
 793          $(filter-out $(vmlinux-init) $(vmlinux-main) $(vmlinux-lds) FORCE ,$^)
 794 define rule_vmlinux-modpost
 795         :
 796         +$(call cmd,vmlinux-modpost)
 797         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost $@
 798         $(Q)echo 'cmd_$@ := $(cmd_vmlinux-modpost)' > $(dot-target).cmd
 799 endef
 800
 801 # vmlinux image - including updated kernel symbols
 802 vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o $(kallsyms.o) FORCE
 803 ifdef CONFIG_HEADERS_CHECK
 804         $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
 805 endif
 806 ifdef CONFIG_SAMPLES
 807         $(Q)$(MAKE) $(build)=samples
 808 endif
 809         $(call vmlinux-modpost)
 810         $(call if_changed_rule,vmlinux__)
 811         $(Q)rm -f .old_version
 812
 813 # build vmlinux.o first to catch section mismatch errors early
 814 ifdef CONFIG_KALLSYMS
 815 .tmp_vmlinux1: vmlinux.o
 816 endif
 817 vmlinux.o: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) FORCE
 818         $(call if_changed_rule,vmlinux-modpost)
 819
 820 # The actual objects are generated when descending,
 821 # make sure no implicit rule kicks in
 822 $(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ;
 823
 824 # Handle descending into subdirectories listed in $(vmlinux-dirs)
 825 # Preset locale variables to speed up the build process. Limit locale
 826 # tweaks to this spot to avoid wrong language settings when running
 827 # make menuconfig etc.
 828 # Error messages still appears in the original language
 829
 830 PHONY += $(vmlinux-dirs)
 831 $(vmlinux-dirs): prepare scripts
 832         $(Q)$(MAKE) $(build)=$@
 833
 834 # Build the kernel release string
 835 #
 836 # The KERNELRELEASE value built here is stored in the file
 837 # include/config/kernel.release, and is used when executing several
 838 # make targets, such as "make install" or "make modules_install."
 839 #
 840 # The eventual kernel release string consists of the following fields,
 841 # shown in a hierarchical format to show how smaller parts are concatenated
 842 # to form the larger and final value, with values coming from places like
 843 # the Makefile, kernel config options, make command line options and/or
 844 # SCM tag information.
 845 #
 846 #       $(KERNELVERSION)
 847 #         $(VERSION)                    eg, 2
 848 #         $(PATCHLEVEL)                 eg, 6
 849 #         $(SUBLEVEL)                   eg, 18
 850 #         $(EXTRAVERSION)               eg, -rc6
 851 #       $(localver-full)
 852 #         $(localver)
 853 #           localversion*               (files without backups, containing '~')
 854 #           $(CONFIG_LOCALVERSION)      (from kernel config setting)
 855 #         $(localver-auto)              (only if CONFIG_LOCALVERSION_AUTO is set)
 856 #           ./scripts/setlocalversion   (SCM tag, if one exists)
 857 #           $(LOCALVERSION)             (from make command line if provided)
 858 #
 859 #  Note how the final $(localver-auto) string is included *only* if the
 860 # kernel config option CONFIG_LOCALVERSION_AUTO is selected.  Also, at the
 861 # moment, only git is supported but other SCMs can edit the script
 862 # scripts/setlocalversion and add the appropriate checks as needed.
 863
 864 pattern = ".*/localversion[^~]*"
 865 string  = $(shell cat /dev/null \
 866            `find $(objtree) $(srctree) -maxdepth 1 -regex $(pattern) | sort -u`)
 867
 868 localver = $(subst $(space),, $(string) \
 869                               $(patsubst "%",%,$(CONFIG_LOCALVERSION)))
 870
 871 # If CONFIG_LOCALVERSION_AUTO is set scripts/setlocalversion is called
 872 # and if the SCM is know a tag from the SCM is appended.
 873 # The appended tag is determined by the SCM used.
 874 #
 875 # Currently, only git is supported.
 876 # Other SCMs can edit scripts/setlocalversion and add the appropriate
 877 # checks as needed.
 878 ifdef CONFIG_LOCALVERSION_AUTO
 879         _localver-auto = $(shell $(CONFIG_SHELL) \
 880                           $(srctree)/scripts/setlocalversion $(srctree))
 881         localver-auto  = $(LOCALVERSION)$(_localver-auto)
 882 endif
 883
 884 localver-full = $(localver)$(localver-auto)
 885
 886 # Store (new) KERNELRELASE string in include/config/kernel.release
 887 kernelrelease = $(KERNELVERSION)$(localver-full)
 888 include/config/kernel.release: include/config/auto.conf FORCE
 889         $(Q)rm -f $@
 890         $(Q)echo $(kernelrelease) > $@
 891
 892
 893 # Things we need to do before we recursively start building the kernel
 894 # or the modules are listed in "prepare".
 895 # A multi level approach is used. prepareN is processed before prepareN-1.
 896 # archprepare is used in arch Makefiles and when processed asm symlink,
 897 # version.h and scripts_basic is processed / created.
 898
 899 # Listed in dependency order
 900 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
 901
 902 # prepare3 is used to check if we are building in a separate output directory,
 903 # and if so do:
 904 # 1) Check that make has not been executed in the kernel src $(srctree)
 905 # 2) Create the include2 directory, used for the second asm symlink
 906 prepare3: include/config/kernel.release
 907 ifneq ($(KBUILD_SRC),)
 908         @echo '  Using $(srctree) as source for kernel'
 909         $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
 910                 echo "  $(srctree) is not clean, please run 'make mrproper'";\
 911                 echo "  in the '$(srctree)' directory.";\
 912                 /bin/false; \
 913         fi;
 914         $(Q)if [ ! -d include2 ]; then mkdir -p include2; fi;
 915         $(Q)ln -fsn $(srctree)/include/asm-$(SRCARCH) include2/asm
 916 endif
 917
 918 # prepare2 creates a makefile if using a separate output directory
 919 prepare2: prepare3 outputmakefile
 920
 921 prepare1: prepare2 include/linux/version.h include/linux/utsrelease.h \
 922                    include/asm include/config/auto.conf
 923         $(cmd_crmodverdir)
 924
 925 archprepare: prepare1 scripts_basic
 926
 927 prepare0: archprepare FORCE
 928         $(Q)$(MAKE) $(build)=.
 929         $(Q)$(MAKE) $(build)=. missing-syscalls
 930
 931 # All the preparing..
 932 prepare: prepare0
 933
 934 # Leave this as default for preprocessing vmlinux.lds.S, which is now
 935 # done in arch/$(ARCH)/kernel/Makefile
 936
 937 export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH)
 938
 939 # The asm symlink changes when $(ARCH) changes.
 940 # Detect this and ask user to run make mrproper
 941
 942 include/asm: FORCE
 943         $(Q)set -e; asmlink=`readlink include/asm | cut -d '-' -f 2`;   \
 944         if [ -L include/asm ]; then                                     \
 945                 if [ "$$asmlink" != "$(SRCARCH)" ]; then                \
 946                         echo "ERROR: the symlink $@ points to asm-$$asmlink but asm-$(SRCARCH) was expected"; \
 947                         echo "       set ARCH or save .config and run 'make mrproper' to fix it";             \
 948                         exit 1;                                         \
 949                 fi;                                                     \
 950         else                                                            \
 951                 echo '  SYMLINK $@ -> include/asm-$(SRCARCH)';          \
 952                 if [ ! -d include ]; then                               \
 953                         mkdir -p include;                               \
 954                 fi;                                                     \
 955                 ln -fsn asm-$(SRCARCH) $@;                              \
 956         fi
 957
 958 # Generate some files
 959 # ---------------------------------------------------------------------------
 960
 961 # KERNELRELEASE can change from a few different places, meaning version.h
 962 # needs to be updated, so this check is forced on all builds
 963
 964 uts_len := 64
 965 define filechk_utsrelease.h
 966         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
 967           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
 968           exit 1;                                                         \
 969         fi;                                                               \
 970         (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
 971 endef
 972
 973 define filechk_version.h
 974         (echo \#define LINUX_VERSION_CODE $(shell                             \
 975         expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL));     \
 976         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
 977 endef
 978
 979 include/linux/version.h: $(srctree)/Makefile FORCE
 980         $(call filechk,version.h)
 981
 982 include/linux/utsrelease.h: include/config/kernel.release FORCE
 983         $(call filechk,utsrelease.h)
 984
 985 # ---------------------------------------------------------------------------
 986
 987 PHONY += depend dep
 988 depend dep:
 989         @echo '*** Warning: make $@ is unnecessary now.'
 990
 991 # ---------------------------------------------------------------------------
 992 # Kernel headers
 993 INSTALL_HDR_PATH=$(objtree)/usr
 994 export INSTALL_HDR_PATH
 995
 996 HDRFILTER=generic i386 x86_64
 997 HDRARCHES=$(filter-out $(HDRFILTER),$(patsubst $(srctree)/include/asm-%/Kbuild,%,$(wildcard $(srctree)/include/asm-*/Kbuild)))
 998
 999 PHONY += headers_install_all
1000 headers_install_all: include/linux/version.h scripts_basic FORCE
1001         $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1002         $(Q)for arch in $(HDRARCHES); do \
1003          $(MAKE) ARCH=$$arch -f $(srctree)/scripts/Makefile.headersinst obj=include BIASMDIR=-bi-$$arch ;\
1004          done
1005
1006 PHONY += headers_install
1007 headers_install: include/linux/version.h scripts_basic FORCE
1008         @if [ ! -r $(srctree)/include/asm-$(SRCARCH)/Kbuild ]; then \
1009           echo '*** Error: Headers not exportable for this architecture ($(SRCARCH))'; \
1010           exit 1 ; fi
1011         $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1012         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.headersinst ARCH=$(SRCARCH) obj=include
1013
1014 PHONY += headers_check_all
1015 headers_check_all: headers_install_all
1016         $(Q)for arch in $(HDRARCHES); do \
1017          $(MAKE) ARCH=$$arch -f $(srctree)/scripts/Makefile.headersinst obj=include BIASMDIR=-bi-$$arch HDRCHECK=1 ;\
1018          done
1019
1020 PHONY += headers_check
1021 headers_check: headers_install
1022         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.headersinst ARCH=$(SRCARCH) obj=include HDRCHECK=1
1023
1024 # ---------------------------------------------------------------------------
1025 # Modules
1026
1027 ifdef CONFIG_MODULES
1028
1029 # By default, build modules as well
1030
1031 all: modules
1032
1033 #       Build modules
1034 #
1035 #       A module can be listed more than once in obj-m resulting in
1036 #       duplicate lines in modules.order files.  Those are removed
1037 #       using awk while concatenating to the final file.
1038
1039 PHONY += modules
1040 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux)
1041         $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1042         @echo '  Building modules, stage 2.';
1043         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1044
1045
1046 # Target to prepare building external modules
1047 PHONY += modules_prepare
1048 modules_prepare: prepare scripts
1049
1050 # Target to install modules
1051 PHONY += modules_install
1052 modules_install: _modinst_ _modinst_post
1053
1054 PHONY += _modinst_
1055 _modinst_:
1056         @if [ -z "`$(DEPMOD) -V 2>/dev/null | grep module-init-tools`" ]; then \
1057                 echo "Warning: you may need to install module-init-tools"; \
1058                 echo "See http://www.codemonkey.org.uk/docs/post-halloween-2.6.txt";\
1059                 sleep 1; \
1060         fi
1061         @rm -rf $(MODLIB)/kernel
1062         @rm -f $(MODLIB)/source
1063         @mkdir -p $(MODLIB)/kernel
1064         @ln -s $(srctree) $(MODLIB)/source
1065         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1066                 rm -f $(MODLIB)/build ; \
1067                 ln -s $(objtree) $(MODLIB)/build ; \
1068         fi
1069         @cp -f $(objtree)/modules.order $(MODLIB)/
1070         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1071
1072 # This depmod is only for convenience to give the initial
1073 # boot a modules.dep even before / is mounted read-write.  However the
1074 # boot script depmod is the master version.
1075 PHONY += _modinst_post
1076 _modinst_post: _modinst_
1077         $(call cmd,depmod)
1078
1079 else # CONFIG_MODULES
1080
1081 # Modules not configured
1082 # ---------------------------------------------------------------------------
1083
1084 modules modules_install: FORCE
1085         @echo
1086         @echo "The present kernel configuration has modules disabled."
1087         @echo "Type 'make config' and enable loadable module support."
1088         @echo "Then build a kernel with module support enabled."
1089         @echo
1090         @exit 1
1091
1092 endif # CONFIG_MODULES
1093
1094 ###
1095 # Cleaning is done on three levels.
1096 # make clean     Delete most generated files
1097 #                Leave enough to build external modules
1098 # make mrproper  Delete the current configuration, and all generated files
1099 # make distclean Remove editor backup files, patch leftover files and the like
1100
1101 # Directories & files removed with 'make clean'
1102 CLEAN_DIRS  += $(MODVERDIR)
1103 CLEAN_FILES +=  vmlinux System.map \
1104                 .tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map
1105
1106 # Directories & files removed with 'make mrproper'
1107 MRPROPER_DIRS  += include/config include2 usr/include
1108 MRPROPER_FILES += .config .config.old include/asm .version .old_version \
1109                   include/linux/autoconf.h include/linux/version.h      \
1110                   include/linux/utsrelease.h                            \
1111                   Module.symvers tags TAGS cscope*
1112
1113 # clean - Delete most, but leave enough to build external modules
1114 #
1115 clean: rm-dirs  := $(CLEAN_DIRS)
1116 clean: rm-files := $(CLEAN_FILES)
1117 clean-dirs      := $(addprefix _clean_,$(srctree) $(vmlinux-alldirs))
1118
1119 PHONY += $(clean-dirs) clean archclean
1120 $(clean-dirs):
1121         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1122
1123 clean: archclean $(clean-dirs)
1124         $(call cmd,rmdirs)
1125         $(call cmd,rmfiles)
1126         @find . $(RCS_FIND_IGNORE) \
1127                 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1128                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1129                 -o -name '*.symtypes' -o -name 'modules.order' \) \
1130                 -type f -print | xargs rm -f
1131
1132 # mrproper - Delete all generated files, including .config
1133 #
1134 mrproper: rm-dirs  := $(wildcard $(MRPROPER_DIRS))
1135 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1136 mrproper-dirs      := $(addprefix _mrproper_,Documentation/DocBook scripts)
1137
1138 PHONY += $(mrproper-dirs) mrproper archmrproper
1139 $(mrproper-dirs):
1140         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1141
1142 mrproper: clean archmrproper $(mrproper-dirs)
1143         $(call cmd,rmdirs)
1144         $(call cmd,rmfiles)
1145
1146 # distclean
1147 #
1148 PHONY += distclean
1149
1150 distclean: mrproper
1151         @find $(srctree) $(RCS_FIND_IGNORE) \
1152                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1153                 -o -name '*.bak' -o -name '#*#' -o -name '.*.orig' \
1154                 -o -name '.*.rej' -o -size 0 \
1155                 -o -name '*%' -o -name '.*.cmd' -o -name 'core' \) \
1156                 -type f -print | xargs rm -f
1157
1158
1159 # Packaging of the kernel to various formats
1160 # ---------------------------------------------------------------------------
1161 # rpm target kept for backward compatibility
1162 package-dir     := $(srctree)/scripts/package
1163
1164 %pkg: include/config/kernel.release FORCE
1165         $(Q)$(MAKE) $(build)=$(package-dir) $@
1166 rpm: include/config/kernel.release FORCE
1167         $(Q)$(MAKE) $(build)=$(package-dir) $@
1168
1169
1170 # Brief documentation of the typical targets used
1171 # ---------------------------------------------------------------------------
1172
1173 boards := $(wildcard $(srctree)/arch/$(ARCH)/configs/*_defconfig)
1174 boards := $(notdir $(boards))
1175
1176 help:
1177         @echo  'Cleaning targets:'
1178         @echo  '  clean           - Remove most generated files but keep the config and'
1179         @echo  '                    enough build support to build external modules'
1180         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1181         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1182         @echo  ''
1183         @echo  'Configuration targets:'
1184         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1185         @echo  ''
1186         @echo  'Other generic targets:'
1187         @echo  '  all             - Build all targets marked with [*]'
1188         @echo  '* vmlinux         - Build the bare kernel'
1189         @echo  '* modules         - Build all modules'
1190         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1191         @echo  '  dir/            - Build all files in dir and below'
1192         @echo  '  dir/file.[ois]  - Build specified target only'
1193         @echo  '  dir/file.ko     - Build module including final link'
1194         @echo  '  prepare         - Set up for building external modules'
1195         @echo  '  tags/TAGS       - Generate tags file for editors'
1196         @echo  '  cscope          - Generate cscope index'
1197         @echo  '  kernelrelease   - Output the release version string'
1198         @echo  '  kernelversion   - Output the version stored in Makefile'
1199         @if [ -r $(srctree)/include/asm-$(SRCARCH)/Kbuild ]; then \
1200          echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1201          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1202          fi
1203         @echo  ''
1204         @echo  'Static analysers'
1205         @echo  '  checkstack      - Generate a list of stack hogs'
1206         @echo  '  namespacecheck  - Name space analysis on compiled kernel'
1207         @echo  '  versioncheck    - Sanity check on version.h usage'
1208         @echo  '  includecheck    - Check for duplicate included header files'
1209         @echo  '  export_report   - List the usages of all exported symbols'
1210         @if [ -r $(srctree)/include/asm-$(SRCARCH)/Kbuild ]; then \
1211          echo  '  headers_check   - Sanity check on exported headers'; \
1212          fi
1213         @echo  ''
1214         @echo  'Kernel packaging:'
1215         @$(MAKE) $(build)=$(package-dir) help
1216         @echo  ''
1217         @echo  'Documentation targets:'
1218         @$(MAKE) -f $(srctree)/Documentation/DocBook/Makefile dochelp
1219         @echo  ''
1220         @echo  'Architecture specific targets ($(ARCH)):'
1221         @$(if $(archhelp),$(archhelp),\
1222                 echo '  No architecture specific help defined for $(ARCH)')
1223         @echo  ''
1224         @$(if $(boards), \
1225                 $(foreach b, $(boards), \
1226                 printf "  %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1227                 echo '')
1228
1229         @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1230         @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1231         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1232         @echo  '  make C=1   [targets] Check all c source with $$CHECK (sparse by default)'
1233         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1234         @echo  ''
1235         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1236         @echo  'For further info see the ./README file'
1237
1238
1239 # Documentation targets
1240 # ---------------------------------------------------------------------------
1241 %docs: scripts_basic FORCE
1242         $(Q)$(MAKE) $(build)=Documentation/DocBook $@
1243
1244 else # KBUILD_EXTMOD
1245
1246 ###
1247 # External module support.
1248 # When building external modules the kernel used as basis is considered
1249 # read-only, and no consistency checks are made and the make
1250 # system is not used on the basis kernel. If updates are required
1251 # in the basis kernel ordinary make commands (without M=...) must
1252 # be used.
1253 #
1254 # The following are the only valid targets when building external
1255 # modules.
1256 # make M=dir clean     Delete all automatically generated files
1257 # make M=dir modules   Make all modules in specified dir
1258 # make M=dir           Same as 'make M=dir modules'
1259 # make M=dir modules_install
1260 #                      Install the modules built in the module directory
1261 #                      Assumes install directory is already created
1262
1263 # We are always building modules
1264 KBUILD_MODULES := 1
1265 PHONY += crmodverdir
1266 crmodverdir:
1267         $(cmd_crmodverdir)
1268
1269 PHONY += $(objtree)/Module.symvers
1270 $(objtree)/Module.symvers:
1271         @test -e $(objtree)/Module.symvers || ( \
1272         echo; \
1273         echo "  WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1274         echo "           is missing; modules will have no dependencies and modversions."; \
1275         echo )
1276
1277 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1278 PHONY += $(module-dirs) modules
1279 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1280         $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1281
1282 modules: $(module-dirs)
1283         @echo '  Building modules, stage 2.';
1284         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1285
1286 PHONY += modules_install
1287 modules_install: _emodinst_ _emodinst_post
1288
1289 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1290 PHONY += _emodinst_
1291 _emodinst_:
1292         $(Q)mkdir -p $(MODLIB)/$(install-dir)
1293         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1294
1295 PHONY += _emodinst_post
1296 _emodinst_post: _emodinst_
1297         $(call cmd,depmod)
1298
1299 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1300
1301 PHONY += $(clean-dirs) clean
1302 $(clean-dirs):
1303         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1304
1305 clean:  rm-dirs := $(MODVERDIR)
1306 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1307 clean: $(clean-dirs)
1308         $(call cmd,rmdirs)
1309         $(call cmd,rmfiles)
1310         @find $(KBUILD_EXTMOD) $(RCS_FIND_IGNORE) \
1311                 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1312                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \) \
1313                 -type f -print | xargs rm -f
1314
1315 help:
1316         @echo  '  Building external modules.'
1317         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1318         @echo  ''
1319         @echo  '  modules         - default target, build the module(s)'
1320         @echo  '  modules_install - install the module'
1321         @echo  '  clean           - remove generated files in module directory only'
1322         @echo  ''
1323
1324 # Dummies...
1325 PHONY += prepare scripts
1326 prepare: ;
1327 scripts: ;
1328 endif # KBUILD_EXTMOD
1329
1330 # Generate tags for editors
1331 # ---------------------------------------------------------------------------
1332
1333 #We want __srctree to totally vanish out when KBUILD_OUTPUT is not set
1334 #(which is the most common case IMHO) to avoid unneeded clutter in the big tags file.
1335 #Adding $(srctree) adds about 20M on i386 to the size of the output file!
1336
1337 ifeq ($(src),$(obj))
1338 __srctree =
1339 else
1340 __srctree = $(srctree)/
1341 endif
1342
1343 ifeq ($(ALLSOURCE_ARCHS),)
1344 ifeq ($(ARCH),um)
1345 ALLINCLUDE_ARCHS := $(ARCH) $(SUBARCH)
1346 else
1347 ALLINCLUDE_ARCHS := $(SRCARCH)
1348 endif
1349 else
1350 #Allow user to specify only ALLSOURCE_PATHS on the command line, keeping existing behaviour.
1351 ALLINCLUDE_ARCHS := $(ALLSOURCE_ARCHS)
1352 endif
1353
1354 ALLSOURCE_ARCHS := $(SRCARCH)
1355
1356 define find-sources
1357         ( for arch in $(ALLSOURCE_ARCHS) ; do \
1358                find $(__srctree)arch/$${arch} $(RCS_FIND_IGNORE) \
1359                     -name $1 -print; \
1360           done ; \
1361           find $(__srctree)security/selinux/include $(RCS_FIND_IGNORE) \
1362                -name $1 -print; \
1363           find $(__srctree)include $(RCS_FIND_IGNORE) \
1364                \( -name config -o -name 'asm-*' \) -prune \
1365                -o -name $1 -print; \
1366           for arch in $(ALLINCLUDE_ARCHS) ; do \
1367                find $(__srctree)include/asm-$${arch} $(RCS_FIND_IGNORE) \
1368                     -name $1 -print; \
1369           done ; \
1370           find $(__srctree)include/asm-generic $(RCS_FIND_IGNORE) \
1371                -name $1 -print; \
1372           find $(__srctree) $(RCS_FIND_IGNORE) \
1373                \( -name include -o -name arch -o -name '.tmp_*' \) -prune -o \
1374                -name $1 -print; \
1375           )
1376 endef
1377
1378 define all-sources
1379         $(call find-sources,'*.[chS]')
1380 endef
1381 define all-kconfigs
1382         $(call find-sources,'Kconfig*')
1383 endef
1384 define all-defconfigs
1385         $(call find-sources,'defconfig')
1386 endef
1387
1388 define xtags
1389         if $1 --version 2>&1 | grep -iq exuberant; then \
1390             $(all-sources) | xargs $1 -a \
1391                 -I __initdata,__exitdata,__acquires,__releases \
1392                 -I __read_mostly,____cacheline_aligned,____cacheline_aligned_in_smp,____cacheline_internodealigned_in_smp \
1393                 -I EXPORT_SYMBOL,EXPORT_SYMBOL_GPL \
1394                 --extra=+f --c-kinds=+px \
1395                 --regex-asm='/^ENTRY\(([^)]*)\).*/\1/'; \
1396             $(all-kconfigs) | xargs $1 -a \
1397                 --langdef=kconfig \
1398                 --language-force=kconfig \
1399                 --regex-kconfig='/^[[:blank:]]*config[[:blank:]]+([[:alnum:]_]+)/\1/'; \
1400             $(all-defconfigs) | xargs -r $1 -a \
1401                 --langdef=dotconfig \
1402                 --language-force=dotconfig \
1403                 --regex-dotconfig='/^#?[[:blank:]]*(CONFIG_[[:alnum:]_]+)/\1/'; \
1404         elif $1 --version 2>&1 | grep -iq emacs; then \
1405             $(all-sources) | xargs $1 -a; \
1406             $(all-kconfigs) | xargs $1 -a \
1407                 --regex='/^[ \t]*config[ \t]+\([a-zA-Z0-9_]+\)/\1/'; \
1408             $(all-defconfigs) | xargs -r $1 -a \
1409                 --regex='/^#?[ \t]?\(CONFIG_[a-zA-Z0-9_]+\)/\1/'; \
1410         else \
1411             $(all-sources) | xargs $1 -a; \
1412         fi
1413 endef
1414
1415 quiet_cmd_cscope-file = FILELST cscope.files
1416       cmd_cscope-file = (echo \-k; echo \-q; $(all-sources)) > cscope.files
1417
1418 quiet_cmd_cscope = MAKE    cscope.out
1419       cmd_cscope = cscope -b
1420
1421 cscope: FORCE
1422         $(call cmd,cscope-file)
1423         $(call cmd,cscope)
1424
1425 quiet_cmd_TAGS = MAKE   $@
1426 define cmd_TAGS
1427         rm -f $@; \
1428         $(call xtags,etags)
1429 endef
1430
1431 TAGS: FORCE
1432         $(call cmd,TAGS)
1433
1434 quiet_cmd_tags = MAKE   $@
1435 define cmd_tags
1436         rm -f $@; \
1437         $(call xtags,ctags)
1438 endef
1439
1440 tags: FORCE
1441         $(call cmd,tags)
1442
1443
1444 # Scripts to check various things for consistency
1445 # ---------------------------------------------------------------------------
1446
1447 includecheck:
1448         find * $(RCS_FIND_IGNORE) \
1449                 -name '*.[hcS]' -type f -print | sort \
1450                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1451
1452 versioncheck:
1453         find * $(RCS_FIND_IGNORE) \
1454                 -name '*.[hcS]' -type f -print | sort \
1455                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1456
1457 namespacecheck:
1458         $(PERL) $(srctree)/scripts/namespace.pl
1459
1460 export_report:
1461         $(PERL) $(srctree)/scripts/export_report.pl
1462
1463 endif #ifeq ($(config-targets),1)
1464 endif #ifeq ($(mixed-targets),1)
1465
1466 PHONY += checkstack kernelrelease kernelversion
1467
1468 # UML needs a little special treatment here.  It wants to use the host
1469 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1470 # else wants $(ARCH), including people doing cross-builds, which means
1471 # that $(SUBARCH) doesn't work here.
1472 ifeq ($(ARCH), um)
1473 CHECKSTACK_ARCH := $(SUBARCH)
1474 else
1475 CHECKSTACK_ARCH := $(ARCH)
1476 endif
1477 checkstack:
1478         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1479         $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1480
1481 kernelrelease:
1482         $(if $(wildcard include/config/kernel.release), $(Q)echo $(KERNELRELEASE), \
1483         $(error kernelrelease not valid - run 'make prepare' to update it))
1484 kernelversion:
1485         @echo $(KERNELVERSION)
1486
1487 # Single targets
1488 # ---------------------------------------------------------------------------
1489 # Single targets are compatible with:
1490 # - build with mixed source and output
1491 # - build with separate output dir 'make O=...'
1492 # - external modules
1493 #
1494 #  target-dir => where to store outputfile
1495 #  build-dir  => directory in kernel source tree to use
1496
1497 ifeq ($(KBUILD_EXTMOD),)
1498         build-dir  = $(patsubst %/,%,$(dir $@))
1499         target-dir = $(dir $@)
1500 else
1501         zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1502         build-dir  = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1503         target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1504 endif
1505
1506 %.s: %.c prepare scripts FORCE
1507         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1508 %.i: %.c prepare scripts FORCE
1509         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1510 %.o: %.c prepare scripts FORCE
1511         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1512 %.lst: %.c prepare scripts FORCE
1513         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1514 %.s: %.S prepare scripts FORCE
1515         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1516 %.o: %.S prepare scripts FORCE
1517         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1518 %.symtypes: %.c prepare scripts FORCE
1519         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1520
1521 # Modules
1522 / %/: prepare scripts FORCE
1523         $(cmd_crmodverdir)
1524         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1525         $(build)=$(build-dir)
1526 %.ko: prepare scripts FORCE
1527         $(cmd_crmodverdir)
1528         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)   \
1529         $(build)=$(build-dir) $(@:.ko=.o)
1530         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1531
1532 # FIXME Should go into a make.lib or something
1533 # ===========================================================================
1534
1535 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN   $(wildcard $(rm-dirs)))
1536       cmd_rmdirs = rm -rf $(rm-dirs)
1537
1538 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1539       cmd_rmfiles = rm -f $(rm-files)
1540
1541 # Run depmod only is we have System.map and depmod is executable
1542 # and we build for the host arch
1543 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
1544       cmd_depmod = \
1545         if [ -r System.map -a -x $(DEPMOD) ]; then                              \
1546                 $(DEPMOD) -ae -F System.map                                     \
1547                 $(if $(strip $(INSTALL_MOD_PATH)), -b $(INSTALL_MOD_PATH) -r)   \
1548                 $(KERNELRELEASE);                                               \
1549         fi
1550
1551 # Create temporary dir for module support files
1552 # clean it up only when building all modules
1553 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1554                   $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1555
1556 a_flags = -Wp,-MD,$(depfile) $(KBUILD_AFLAGS) $(AFLAGS_KERNEL) \
1557           $(NOSTDINC_FLAGS) $(KBUILD_CPPFLAGS) \
1558           $(modkern_aflags) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o)
1559
1560 quiet_cmd_as_o_S = AS      $@
1561 cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ $<
1562
1563 # read all saved command lines
1564
1565 targets := $(wildcard $(sort $(targets)))
1566 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1567
1568 ifneq ($(cmd_files),)
1569   $(cmd_files): ;       # Do not try to update included dependency files
1570   include $(cmd_files)
1571 endif
1572
1573 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=dir
1574 # Usage:
1575 # $(Q)$(MAKE) $(clean)=dir
1576 clean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean obj
1577
1578 endif   # skip-makefile
1579
1580 PHONY += FORCE
1581 FORCE:
1582
1583 # Declare the contents of the .PHONY variable as phony.  We keep that
1584 # information in a variable se we can use it in if_changed and friends.
1585 .PHONY: $(PHONY)