Makefile

   1 VERSION = 2
   2 PATCHLEVEL = 6
   3 SUBLEVEL = 39
   4 EXTRAVERSION =
   5 NAME = Flesh-Eating Bats with Fangs
   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 # We are using a recursive build, so we need to do a little thinking
  26 # to get the ordering right.
  27 #
  28 # Most importantly: sub-Makefiles should only ever modify files in
  29 # their own directory. If in some directory we have a dependency on
  30 # a file in another dir (which doesn't happen often, but it's often
  31 # unavoidable when linking the built-in.o targets which finally
  32 # turn into vmlinux), we will call a sub make in that other dir, and
  33 # after that we are sure that everything which is in that other dir
  34 # is now up to date.
  35 #
  36 # The only cases where we need to modify files which have global
  37 # effects are thus separated out and done before the recursive
  38 # descending is started. They are now explicitly listed as the
  39 # prepare rule.
  40
  41 # To put more focus on warnings, be less verbose as default
  42 # Use 'make V=1' to see the full commands
  43
  44 ifeq ("$(origin V)", "command line")
  45   KBUILD_VERBOSE = $(V)
  46 endif
  47 ifndef KBUILD_VERBOSE
  48   KBUILD_VERBOSE = 0
  49 endif
  50
  51 # Call a source code checker (by default, "sparse") as part of the
  52 # C compilation.
  53 #
  54 # Use 'make C=1' to enable checking of only re-compiled files.
  55 # Use 'make C=2' to enable checking of *all* source files, regardless
  56 # of whether they are re-compiled or not.
  57 #
  58 # See the file "Documentation/sparse.txt" for more details, including
  59 # where to get the "sparse" utility.
  60
  61 ifeq ("$(origin C)", "command line")
  62   KBUILD_CHECKSRC = $(C)
  63 endif
  64 ifndef KBUILD_CHECKSRC
  65   KBUILD_CHECKSRC = 0
  66 endif
  67
  68 # Use make M=dir to specify directory of external module to build
  69 # Old syntax make ... SUBDIRS=$PWD is still supported
  70 # Setting the environment variable KBUILD_EXTMOD take precedence
  71 ifdef SUBDIRS
  72   KBUILD_EXTMOD ?= $(SUBDIRS)
  73 endif
  74
  75 ifeq ("$(origin M)", "command line")
  76   KBUILD_EXTMOD := $(M)
  77 endif
  78
  79 # kbuild supports saving output files in a separate directory.
  80 # To locate output files in a separate directory two syntaxes are supported.
  81 # In both cases the working directory must be the root of the kernel src.
  82 # 1) O=
  83 # Use "make O=dir/to/store/output/files/"
  84 #
  85 # 2) Set KBUILD_OUTPUT
  86 # Set the environment variable KBUILD_OUTPUT to point to the directory
  87 # where the output files shall be placed.
  88 # export KBUILD_OUTPUT=dir/to/store/output/files/
  89 # make
  90 #
  91 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
  92 # variable.
  93
  94
  95 # KBUILD_SRC is set on invocation of make in OBJ directory
  96 # KBUILD_SRC is not intended to be used by the regular user (for now)
  97 ifeq ($(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 ifeq ("$(origin O)", "command line")
 102   KBUILD_OUTPUT := $(O)
 103 endif
 104
 105 ifeq ("$(origin W)", "command line")
 106   export KBUILD_ENABLE_EXTRA_GCC_CHECKS := $(W)
 107 endif
 108
 109 # That's our default target when none is given on the command line
 110 PHONY := _all
 111 _all:
 112
 113 # Cancel implicit rules on top Makefile
 114 $(CURDIR)/Makefile Makefile: ;
 115
 116 ifneq ($(KBUILD_OUTPUT),)
 117 # Invoke a second make in the output directory, passing relevant variables
 118 # check that the output directory actually exists
 119 saved-output := $(KBUILD_OUTPUT)
 120 KBUILD_OUTPUT := $(shell cd $(KBUILD_OUTPUT) && /bin/pwd)
 121 $(if $(KBUILD_OUTPUT),, \
 122      $(error output directory "$(saved-output)" does not exist))
 123
 124 PHONY += $(MAKECMDGOALS) sub-make
 125
 126 $(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
 127         $(Q)@:
 128
 129 sub-make: FORCE
 130         $(if $(KBUILD_VERBOSE:1=),@)$(MAKE) -C $(KBUILD_OUTPUT) \
 131         KBUILD_SRC=$(CURDIR) \
 132         KBUILD_EXTMOD="$(KBUILD_EXTMOD)" -f $(CURDIR)/Makefile \
 133         $(filter-out _all sub-make,$(MAKECMDGOALS))
 134
 135 # Leave processing to above invocation of make
 136 skip-makefile := 1
 137 endif # ifneq ($(KBUILD_OUTPUT),)
 138 endif # ifeq ($(KBUILD_SRC),)
 139
 140 # We process the rest of the Makefile if this is the final invocation of make
 141 ifeq ($(skip-makefile),)
 142
 143 # If building an external module we do not care about the all: rule
 144 # but instead _all depend on modules
 145 PHONY += all
 146 ifeq ($(KBUILD_EXTMOD),)
 147 _all: all
 148 else
 149 _all: modules
 150 endif
 151
 152 srctree         := $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR))
 153 objtree         := $(CURDIR)
 154 src             := $(srctree)
 155 obj             := $(objtree)
 156
 157 VPATH           := $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
 158
 159 export srctree objtree VPATH
 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[234].*/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 # A third alternative is to store a setting in .config so that plain
 191 # "make" in the configured kernel build directory always uses that.
 192 # Default value for CROSS_COMPILE is not to prefix executables
 193 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 194 export KBUILD_BUILDHOST := $(SUBARCH)
 195 ARCH            ?= $(SUBARCH)
 196 CROSS_COMPILE   ?= $(CONFIG_CROSS_COMPILE:"%"=%)
 197
 198 # Architecture as present in compile.h
 199 UTS_MACHINE     := $(ARCH)
 200 SRCARCH         := $(ARCH)
 201
 202 # Additional ARCH settings for x86
 203 ifeq ($(ARCH),i386)
 204         SRCARCH := x86
 205 endif
 206 ifeq ($(ARCH),x86_64)
 207         SRCARCH := x86
 208 endif
 209
 210 # Additional ARCH settings for sparc
 211 ifeq ($(ARCH),sparc32)
 212        SRCARCH := sparc
 213 endif
 214 ifeq ($(ARCH),sparc64)
 215        SRCARCH := sparc
 216 endif
 217
 218 # Additional ARCH settings for sh
 219 ifeq ($(ARCH),sh64)
 220        SRCARCH := sh
 221 endif
 222
 223 # Where to locate arch specific headers
 224 hdr-arch  := $(SRCARCH)
 225
 226 ifeq ($(ARCH),m68knommu)
 227        hdr-arch  := m68k
 228 endif
 229
 230 KCONFIG_CONFIG  ?= .config
 231 export KCONFIG_CONFIG
 232
 233 # SHELL used by kbuild
 234 CONFIG_SHELL := $(shell if [ -x "$$BASH" ]; then echo $$BASH; \
 235           else if [ -x /bin/bash ]; then echo /bin/bash; \
 236           else echo sh; fi ; fi)
 237
 238 HOSTCC       = gcc
 239 HOSTCXX      = g++
 240 HOSTCFLAGS   = -Wall -Wmissing-prototypes -Wstrict-prototypes -O2 -fomit-frame-pointer
 241 HOSTCXXFLAGS = -O2
 242
 243 # Decide whether to build built-in, modular, or both.
 244 # Normally, just do built-in.
 245
 246 KBUILD_MODULES :=
 247 KBUILD_BUILTIN := 1
 248
 249 #       If we have only "make modules", don't compile built-in objects.
 250 #       When we're building modules with modversions, we need to consider
 251 #       the built-in objects during the descend as well, in order to
 252 #       make sure the checksums are up to date before we record them.
 253
 254 ifeq ($(MAKECMDGOALS),modules)
 255   KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
 256 endif
 257
 258 #       If we have "make <whatever> modules", compile modules
 259 #       in addition to whatever we do anyway.
 260 #       Just "make" or "make all" shall build modules as well
 261
 262 ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
 263   KBUILD_MODULES := 1
 264 endif
 265
 266 ifeq ($(MAKECMDGOALS),)
 267   KBUILD_MODULES := 1
 268 endif
 269
 270 export KBUILD_MODULES KBUILD_BUILTIN
 271 export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
 272
 273 # Beautify output
 274 # ---------------------------------------------------------------------------
 275 #
 276 # Normally, we echo the whole command before executing it. By making
 277 # that echo $($(quiet)$(cmd)), we now have the possibility to set
 278 # $(quiet) to choose other forms of output instead, e.g.
 279 #
 280 #         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
 281 #         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
 282 #
 283 # If $(quiet) is empty, the whole command will be printed.
 284 # If it is set to "quiet_", only the short version will be printed.
 285 # If it is set to "silent_", nothing will be printed at all, since
 286 # the variable $(silent_cmd_cc_o_c) doesn't exist.
 287 #
 288 # A simple variant is to prefix commands with $(Q) - that's useful
 289 # for commands that shall be hidden in non-verbose mode.
 290 #
 291 #       $(Q)ln $@ :<
 292 #
 293 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
 294 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
 295
 296 ifeq ($(KBUILD_VERBOSE),1)
 297   quiet =
 298   Q =
 299 else
 300   quiet=quiet_
 301   Q = @
 302 endif
 303
 304 # If the user is running make -s (silent mode), suppress echoing of
 305 # commands
 306
 307 ifneq ($(findstring s,$(MAKEFLAGS)),)
 308   quiet=silent_
 309 endif
 310
 311 export quiet Q KBUILD_VERBOSE
 312
 313
 314 # Look for make include files relative to root of kernel src
 315 MAKEFLAGS += --include-dir=$(srctree)
 316
 317 # We need some generic definitions (do not try to remake the file).
 318 $(srctree)/scripts/Kbuild.include: ;
 319 include $(srctree)/scripts/Kbuild.include
 320
 321 # Make variables (CC, etc...)
 322
 323 AS              = $(CROSS_COMPILE)as
 324 LD              = $(CROSS_COMPILE)ld
 325 CC              = $(CROSS_COMPILE)gcc
 326 CPP             = $(CC) -E
 327 AR              = $(CROSS_COMPILE)ar
 328 NM              = $(CROSS_COMPILE)nm
 329 STRIP           = $(CROSS_COMPILE)strip
 330 OBJCOPY         = $(CROSS_COMPILE)objcopy
 331 OBJDUMP         = $(CROSS_COMPILE)objdump
 332 AWK             = awk
 333 GENKSYMS        = scripts/genksyms/genksyms
 334 INSTALLKERNEL  := installkernel
 335 DEPMOD          = /sbin/depmod
 336 KALLSYMS        = scripts/kallsyms
 337 PERL            = perl
 338 CHECK           = sparse
 339
 340 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 341                   -Wbitwise -Wno-return-void $(CF)
 342 CFLAGS_MODULE   =
 343 AFLAGS_MODULE   =
 344 LDFLAGS_MODULE  =
 345 CFLAGS_KERNEL   =
 346 AFLAGS_KERNEL   =
 347 CFLAGS_GCOV     = -fprofile-arcs -ftest-coverage
 348
 349
 350 # Use LINUXINCLUDE when you must reference the include/ directory.
 351 # Needed to be compatible with the O= option
 352 LINUXINCLUDE    := -I$(srctree)/arch/$(hdr-arch)/include \
 353                    -Iarch/$(hdr-arch)/include/generated -Iinclude \
 354                    $(if $(KBUILD_SRC), -I$(srctree)/include) \
 355                    -include include/generated/autoconf.h
 356
 357 KBUILD_CPPFLAGS := -D__KERNEL__
 358
 359 KBUILD_CFLAGS   := -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs \
 360                    -fno-strict-aliasing -fno-common \
 361                    -Werror-implicit-function-declaration \
 362                    -Wno-format-security \
 363                    -fno-delete-null-pointer-checks
 364 KBUILD_AFLAGS_KERNEL :=
 365 KBUILD_CFLAGS_KERNEL :=
 366 KBUILD_AFLAGS   := -D__ASSEMBLY__
 367 KBUILD_AFLAGS_MODULE  := -DMODULE
 368 KBUILD_CFLAGS_MODULE  := -DMODULE
 369 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds
 370
 371 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 372 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 373 KERNELVERSION = $(VERSION).$(PATCHLEVEL).$(SUBLEVEL)$(EXTRAVERSION)
 374
 375 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 376 export ARCH SRCARCH CONFIG_SHELL HOSTCC HOSTCFLAGS CROSS_COMPILE AS LD CC
 377 export CPP AR NM STRIP OBJCOPY OBJDUMP
 378 export MAKE AWK GENKSYMS INSTALLKERNEL PERL UTS_MACHINE
 379 export HOSTCXX HOSTCXXFLAGS LDFLAGS_MODULE CHECK CHECKFLAGS
 380
 381 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS LDFLAGS
 382 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE CFLAGS_GCOV
 383 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 384 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 385 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 386 export KBUILD_ARFLAGS
 387
 388 # When compiling out-of-tree modules, put MODVERDIR in the module
 389 # tree rather than in the kernel tree. The kernel tree might
 390 # even be read-only.
 391 export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
 392
 393 # Files to ignore in find ... statements
 394
 395 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
 396 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn --exclude CVS --exclude .pc --exclude .hg --exclude .git
 397
 398 # ===========================================================================
 399 # Rules shared between *config targets and build targets
 400
 401 # Basic helpers built in scripts/
 402 PHONY += scripts_basic
 403 scripts_basic:
 404         $(Q)$(MAKE) $(build)=scripts/basic
 405         $(Q)rm -f .tmp_quiet_recordmcount
 406
 407 # To avoid any implicit rule to kick in, define an empty command.
 408 scripts/basic/%: scripts_basic ;
 409
 410 PHONY += outputmakefile
 411 # outputmakefile generates a Makefile in the output directory, if using a
 412 # separate output directory. This allows convenient use of make in the
 413 # output directory.
 414 outputmakefile:
 415 ifneq ($(KBUILD_SRC),)
 416         $(Q)ln -fsn $(srctree) source
 417         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile \
 418             $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
 419 endif
 420
 421 # Support for using generic headers in asm-generic
 422 PHONY += asm-generic
 423 asm-generic:
 424         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
 425                     obj=arch/$(SRCARCH)/include/generated/asm
 426
 427 # To make sure we do not include .config for any of the *config targets
 428 # catch them early, and hand them over to scripts/kconfig/Makefile
 429 # It is allowed to specify more targets when calling make, including
 430 # mixing *config targets and build targets.
 431 # For example 'make oldconfig all'.
 432 # Detect when mixed targets is specified, and make a second invocation
 433 # of make so .config is not included in this case either (for *config).
 434
 435 no-dot-config-targets := clean mrproper distclean \
 436                          cscope gtags TAGS tags help %docs check% coccicheck \
 437                          include/linux/version.h headers_% \
 438                          kernelversion %src-pkg
 439
 440 config-targets := 0
 441 mixed-targets  := 0
 442 dot-config     := 1
 443
 444 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 445         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 446                 dot-config := 0
 447         endif
 448 endif
 449
 450 ifeq ($(KBUILD_EXTMOD),)
 451         ifneq ($(filter config %config,$(MAKECMDGOALS)),)
 452                 config-targets := 1
 453                 ifneq ($(filter-out config %config,$(MAKECMDGOALS)),)
 454                         mixed-targets := 1
 455                 endif
 456         endif
 457 endif
 458
 459 ifeq ($(mixed-targets),1)
 460 # ===========================================================================
 461 # We're called with mixed targets (*config and build targets).
 462 # Handle them one by one.
 463
 464 %:: FORCE
 465         $(Q)$(MAKE) -C $(srctree) KBUILD_SRC= $@
 466
 467 else
 468 ifeq ($(config-targets),1)
 469 # ===========================================================================
 470 # *config targets only - make sure prerequisites are updated, and descend
 471 # in scripts/kconfig to make the *config target
 472
 473 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 474 # KBUILD_DEFCONFIG may point out an alternative default configuration
 475 # used for 'make defconfig'
 476 include $(srctree)/arch/$(SRCARCH)/Makefile
 477 export KBUILD_DEFCONFIG KBUILD_KCONFIG
 478
 479 config: scripts_basic outputmakefile FORCE
 480         $(Q)mkdir -p include/linux include/config
 481         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 482
 483 %config: scripts_basic outputmakefile FORCE
 484         $(Q)mkdir -p include/linux include/config
 485         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 486
 487 else
 488 # ===========================================================================
 489 # Build targets only - this includes vmlinux, arch specific targets, clean
 490 # targets and others. In general all targets except *config targets.
 491
 492 ifeq ($(KBUILD_EXTMOD),)
 493 # Additional helpers built in scripts/
 494 # Carefully list dependencies so we do not try to build scripts twice
 495 # in parallel
 496 PHONY += scripts
 497 scripts: scripts_basic include/config/auto.conf include/config/tristate.conf
 498         $(Q)$(MAKE) $(build)=$(@)
 499
 500 # Objects we will link into vmlinux / subdirs we need to visit
 501 init-y          := init/
 502 drivers-y       := drivers/ sound/ firmware/
 503 net-y           := net/
 504 libs-y          := lib/
 505 core-y          := usr/
 506 endif # KBUILD_EXTMOD
 507
 508 ifeq ($(dot-config),1)
 509 # Read in config
 510 -include include/config/auto.conf
 511
 512 ifeq ($(KBUILD_EXTMOD),)
 513 # Read in dependencies to all Kconfig* files, make sure to run
 514 # oldconfig if changes are detected.
 515 -include include/config/auto.conf.cmd
 516
 517 # To avoid any implicit rule to kick in, define an empty command
 518 $(KCONFIG_CONFIG) include/config/auto.conf.cmd: ;
 519
 520 # If .config is newer than include/config/auto.conf, someone tinkered
 521 # with it and forgot to run make oldconfig.
 522 # if auto.conf.cmd is missing then we are probably in a cleaned tree so
 523 # we execute the config step to be sure to catch updated Kconfig files
 524 include/config/%.conf: $(KCONFIG_CONFIG) include/config/auto.conf.cmd
 525         $(Q)$(MAKE) -f $(srctree)/Makefile silentoldconfig
 526 else
 527 # external modules needs include/generated/autoconf.h and include/config/auto.conf
 528 # but do not care if they are up-to-date. Use auto.conf to trigger the test
 529 PHONY += include/config/auto.conf
 530
 531 include/config/auto.conf:
 532         $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 533         echo;                                                           \
 534         echo "  ERROR: Kernel configuration is invalid.";               \
 535         echo "         include/generated/autoconf.h or $@ are missing.";\
 536         echo "         Run 'make oldconfig && make prepare' on kernel src to fix it.";  \
 537         echo;                                                           \
 538         /bin/false)
 539
 540 endif # KBUILD_EXTMOD
 541
 542 else
 543 # Dummy target needed, because used as prerequisite
 544 include/config/auto.conf: ;
 545 endif # $(dot-config)
 546
 547 # The all: target is the default when no target is given on the
 548 # command line.
 549 # This allow a user to issue only 'make' to build a kernel including modules
 550 # Defaults to vmlinux, but the arch makefile usually adds further targets
 551 all: vmlinux
 552
 553 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 554 KBUILD_CFLAGS   += -Os
 555 else
 556 KBUILD_CFLAGS   += -O2
 557 endif
 558
 559 include $(srctree)/arch/$(SRCARCH)/Makefile
 560
 561 ifneq ($(CONFIG_FRAME_WARN),0)
 562 KBUILD_CFLAGS += $(call cc-option,-Wframe-larger-than=${CONFIG_FRAME_WARN})
 563 endif
 564
 565 # Force gcc to behave correct even for buggy distributions
 566 ifndef CONFIG_CC_STACKPROTECTOR
 567 KBUILD_CFLAGS += $(call cc-option, -fno-stack-protector)
 568 endif
 569
 570 # This warning generated too much noise in a regular build.
 571 # Use make W=1 to enable this warning (see scripts/Makefile.build)
 572 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 573
 574 ifdef CONFIG_FRAME_POINTER
 575 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 576 else
 577 # Some targets (ARM with Thumb2, for example), can't be built with frame
 578 # pointers.  For those, we don't have FUNCTION_TRACER automatically
 579 # select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 580 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
 581 # -fomit-frame-pointer with FUNCTION_TRACER.
 582 ifndef CONFIG_FUNCTION_TRACER
 583 KBUILD_CFLAGS   += -fomit-frame-pointer
 584 endif
 585 endif
 586
 587 ifdef CONFIG_DEBUG_INFO
 588 KBUILD_CFLAGS   += -g
 589 KBUILD_AFLAGS   += -gdwarf-2
 590 endif
 591
 592 ifdef CONFIG_DEBUG_INFO_REDUCED
 593 KBUILD_CFLAGS   += $(call cc-option, -femit-struct-debug-baseonly)
 594 endif
 595
 596 ifdef CONFIG_FUNCTION_TRACER
 597 KBUILD_CFLAGS   += -pg
 598 ifdef CONFIG_DYNAMIC_FTRACE
 599         ifdef CONFIG_HAVE_C_RECORDMCOUNT
 600                 BUILD_C_RECORDMCOUNT := y
 601                 export BUILD_C_RECORDMCOUNT
 602         endif
 603 endif
 604 endif
 605
 606 # We trigger additional mismatches with less inlining
 607 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 608 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 609 endif
 610
 611 # arch Makefile may override CC so keep this after arch Makefile is included
 612 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 613 CHECKFLAGS     += $(NOSTDINC_FLAGS)
 614
 615 # warn about C99 declaration after statement
 616 KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)
 617
 618 # disable pointer signed / unsigned warnings in gcc 4.0
 619 KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)
 620
 621 # disable invalid "can't wrap" optimizations for signed / pointers
 622 KBUILD_CFLAGS   += $(call cc-option,-fno-strict-overflow)
 623
 624 # conserve stack if available
 625 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
 626
 627 # use the deterministic mode of AR if available
 628 KBUILD_ARFLAGS := $(call ar-option,D)
 629
 630 # check for 'asm goto'
 631 ifeq ($(shell $(CONFIG_SHELL) $(srctree)/scripts/gcc-goto.sh $(CC)), y)
 632         KBUILD_CFLAGS += -DCC_HAVE_ASM_GOTO
 633 endif
 634
 635 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 636 # But warn user when we do so
 637 warn-assign = \
 638 $(warning "WARNING: Appending $$K$(1) ($(K$(1))) from $(origin K$(1)) to kernel $$$(1)")
 639
 640 ifneq ($(KCPPFLAGS),)
 641         $(call warn-assign,CPPFLAGS)
 642         KBUILD_CPPFLAGS += $(KCPPFLAGS)
 643 endif
 644 ifneq ($(KAFLAGS),)
 645         $(call warn-assign,AFLAGS)
 646         KBUILD_AFLAGS += $(KAFLAGS)
 647 endif
 648 ifneq ($(KCFLAGS),)
 649         $(call warn-assign,CFLAGS)
 650         KBUILD_CFLAGS += $(KCFLAGS)
 651 endif
 652
 653 # Use --build-id when available.
 654 LDFLAGS_BUILD_ID = $(patsubst -Wl$(comma)%,%,\
 655                               $(call cc-ldoption, -Wl$(comma)--build-id,))
 656 KBUILD_LDFLAGS_MODULE += $(LDFLAGS_BUILD_ID)
 657 LDFLAGS_vmlinux += $(LDFLAGS_BUILD_ID)
 658
 659 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
 660 LDFLAGS_vmlinux += $(call ld-option, -X,)
 661 endif
 662
 663 # Default kernel image to build when no specific target is given.
 664 # KBUILD_IMAGE may be overruled on the command line or
 665 # set in the environment
 666 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
 667 # this default value
 668 export KBUILD_IMAGE ?= vmlinux
 669
 670 #
 671 # INSTALL_PATH specifies where to place the updated kernel and system map
 672 # images. Default is /boot, but you can set it to other values
 673 export  INSTALL_PATH ?= /boot
 674
 675 #
 676 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
 677 # relocations required by build roots.  This is not defined in the
 678 # makefile but the argument can be passed to make if needed.
 679 #
 680
 681 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
 682 export MODLIB
 683
 684 #
 685 #  INSTALL_MOD_STRIP, if defined, will cause modules to be
 686 #  stripped after they are installed.  If INSTALL_MOD_STRIP is '1', then
 687 #  the default option --strip-debug will be used.  Otherwise,
 688 #  INSTALL_MOD_STRIP value will be used as the options to the strip command.
 689
 690 ifdef INSTALL_MOD_STRIP
 691 ifeq ($(INSTALL_MOD_STRIP),1)
 692 mod_strip_cmd = $(STRIP) --strip-debug
 693 else
 694 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
 695 endif # INSTALL_MOD_STRIP=1
 696 else
 697 mod_strip_cmd = true
 698 endif # INSTALL_MOD_STRIP
 699 export mod_strip_cmd
 700
 701
 702 ifeq ($(KBUILD_EXTMOD),)
 703 core-y          += kernel/ mm/ fs/ ipc/ security/ crypto/ block/
 704
 705 vmlinux-dirs    := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
 706                      $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
 707                      $(net-y) $(net-m) $(libs-y) $(libs-m)))
 708
 709 vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
 710                      $(init-n) $(init-) \
 711                      $(core-n) $(core-) $(drivers-n) $(drivers-) \
 712                      $(net-n)  $(net-)  $(libs-n)    $(libs-))))
 713
 714 init-y          := $(patsubst %/, %/built-in.o, $(init-y))
 715 core-y          := $(patsubst %/, %/built-in.o, $(core-y))
 716 drivers-y       := $(patsubst %/, %/built-in.o, $(drivers-y))
 717 net-y           := $(patsubst %/, %/built-in.o, $(net-y))
 718 libs-y1         := $(patsubst %/, %/lib.a, $(libs-y))
 719 libs-y2         := $(patsubst %/, %/built-in.o, $(libs-y))
 720 libs-y          := $(libs-y1) $(libs-y2)
 721
 722 # Build vmlinux
 723 # ---------------------------------------------------------------------------
 724 # vmlinux is built from the objects selected by $(vmlinux-init) and
 725 # $(vmlinux-main). Most are built-in.o files from top-level directories
 726 # in the kernel tree, others are specified in arch/$(ARCH)/Makefile.
 727 # Ordering when linking is important, and $(vmlinux-init) must be first.
 728 #
 729 # vmlinux
 730 #   ^
 731 #   |
 732 #   +-< $(vmlinux-init)
 733 #   |   +--< init/version.o + more
 734 #   |
 735 #   +--< $(vmlinux-main)
 736 #   |    +--< driver/built-in.o mm/built-in.o + more
 737 #   |
 738 #   +-< kallsyms.o (see description in CONFIG_KALLSYMS section)
 739 #
 740 # vmlinux version (uname -v) cannot be updated during normal
 741 # descending-into-subdirs phase since we do not yet know if we need to
 742 # update vmlinux.
 743 # Therefore this step is delayed until just before final link of vmlinux -
 744 # except in the kallsyms case where it is done just before adding the
 745 # symbols to the kernel.
 746 #
 747 # System.map is generated to document addresses of all kernel symbols
 748
 749 vmlinux-init := $(head-y) $(init-y)
 750 vmlinux-main := $(core-y) $(libs-y) $(drivers-y) $(net-y)
 751 vmlinux-all  := $(vmlinux-init) $(vmlinux-main)
 752 vmlinux-lds  := arch/$(SRCARCH)/kernel/vmlinux.lds
 753 export KBUILD_VMLINUX_OBJS := $(vmlinux-all)
 754
 755 # Rule to link vmlinux - also used during CONFIG_KALLSYMS
 756 # May be overridden by arch/$(ARCH)/Makefile
 757 quiet_cmd_vmlinux__ ?= LD      $@
 758       cmd_vmlinux__ ?= $(LD) $(LDFLAGS) $(LDFLAGS_vmlinux) -o $@ \
 759       -T $(vmlinux-lds) $(vmlinux-init)                          \
 760       --start-group $(vmlinux-main) --end-group                  \
 761       $(filter-out $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o FORCE ,$^)
 762
 763 # Generate new vmlinux version
 764 quiet_cmd_vmlinux_version = GEN     .version
 765       cmd_vmlinux_version = set -e;                     \
 766         if [ ! -r .version ]; then                      \
 767           rm -f .version;                               \
 768           echo 1 >.version;                             \
 769         else                                            \
 770           mv .version .old_version;                     \
 771           expr 0$$(cat .old_version) + 1 >.version;     \
 772         fi;                                             \
 773         $(MAKE) $(build)=init
 774
 775 # Generate System.map
 776 quiet_cmd_sysmap = SYSMAP
 777       cmd_sysmap = $(CONFIG_SHELL) $(srctree)/scripts/mksysmap
 778
 779 # Link of vmlinux
 780 # If CONFIG_KALLSYMS is set .version is already updated
 781 # Generate System.map and verify that the content is consistent
 782 # Use + in front of the vmlinux_version rule to silent warning with make -j2
 783 # First command is ':' to allow us to use + in front of the rule
 784 define rule_vmlinux__
 785         :
 786         $(if $(CONFIG_KALLSYMS),,+$(call cmd,vmlinux_version))
 787
 788         $(call cmd,vmlinux__)
 789         $(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
 790
 791         $(Q)$(if $($(quiet)cmd_sysmap),                                      \
 792           echo '  $($(quiet)cmd_sysmap)  System.map' &&)                     \
 793         $(cmd_sysmap) $@ System.map;                                         \
 794         if [ $$? -ne 0 ]; then                                               \
 795                 rm -f $@;                                                    \
 796                 /bin/false;                                                  \
 797         fi;
 798         $(verify_kallsyms)
 799 endef
 800
 801
 802 ifdef CONFIG_KALLSYMS
 803 # Generate section listing all symbols and add it into vmlinux $(kallsyms.o)
 804 # It's a three stage process:
 805 # o .tmp_vmlinux1 has all symbols and sections, but __kallsyms is
 806 #   empty
 807 #   Running kallsyms on that gives us .tmp_kallsyms1.o with
 808 #   the right size - vmlinux version (uname -v) is updated during this step
 809 # o .tmp_vmlinux2 now has a __kallsyms section of the right size,
 810 #   but due to the added section, some addresses have shifted.
 811 #   From here, we generate a correct .tmp_kallsyms2.o
 812 # o The correct .tmp_kallsyms2.o is linked into the final vmlinux.
 813 # o Verify that the System.map from vmlinux matches the map from
 814 #   .tmp_vmlinux2, just in case we did not generate kallsyms correctly.
 815 # o If 'make KALLSYMS_EXTRA_PASS=1" was used, do an extra pass using
 816 #   .tmp_vmlinux3 and .tmp_kallsyms3.o.  This is only meant as a
 817 #   temporary bypass to allow the kernel to be built while the
 818 #   maintainers work out what went wrong with kallsyms.
 819
 820 last_kallsyms := 2
 821
 822 ifdef KALLSYMS_EXTRA_PASS
 823 ifneq ($(KALLSYMS_EXTRA_PASS),0)
 824 last_kallsyms := 3
 825 endif
 826 endif
 827
 828 kallsyms.o := .tmp_kallsyms$(last_kallsyms).o
 829
 830 define verify_kallsyms
 831         $(Q)$(if $($(quiet)cmd_sysmap),                                      \
 832           echo '  $($(quiet)cmd_sysmap)  .tmp_System.map' &&)                \
 833           $(cmd_sysmap) .tmp_vmlinux$(last_kallsyms) .tmp_System.map
 834         $(Q)cmp -s System.map .tmp_System.map ||                             \
 835                 (echo Inconsistent kallsyms data;                            \
 836                  echo This is a bug - please report about it;                \
 837                  echo Try "make KALLSYMS_EXTRA_PASS=1" as a workaround;      \
 838                  rm .tmp_kallsyms* ; /bin/false )
 839 endef
 840
 841 # Update vmlinux version before link
 842 # Use + in front of this rule to silent warning about make -j1
 843 # First command is ':' to allow us to use + in front of this rule
 844 cmd_ksym_ld = $(cmd_vmlinux__)
 845 define rule_ksym_ld
 846         :
 847         +$(call cmd,vmlinux_version)
 848         $(call cmd,vmlinux__)
 849         $(Q)echo 'cmd_$@ := $(cmd_vmlinux__)' > $(@D)/.$(@F).cmd
 850 endef
 851
 852 # Generate .S file with all kernel symbols
 853 quiet_cmd_kallsyms = KSYM    $@
 854       cmd_kallsyms = $(NM) -n $< | $(KALLSYMS) \
 855                      $(if $(CONFIG_KALLSYMS_ALL),--all-symbols) > $@
 856
 857 .tmp_kallsyms1.o .tmp_kallsyms2.o .tmp_kallsyms3.o: %.o: %.S scripts FORCE
 858         $(call if_changed_dep,as_o_S)
 859
 860 .tmp_kallsyms%.S: .tmp_vmlinux% $(KALLSYMS)
 861         $(call cmd,kallsyms)
 862
 863 # .tmp_vmlinux1 must be complete except kallsyms, so update vmlinux version
 864 .tmp_vmlinux1: $(vmlinux-lds) $(vmlinux-all) FORCE
 865         $(call if_changed_rule,ksym_ld)
 866
 867 .tmp_vmlinux2: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms1.o FORCE
 868         $(call if_changed,vmlinux__)
 869
 870 .tmp_vmlinux3: $(vmlinux-lds) $(vmlinux-all) .tmp_kallsyms2.o FORCE
 871         $(call if_changed,vmlinux__)
 872
 873 # Needs to visit scripts/ before $(KALLSYMS) can be used.
 874 $(KALLSYMS): scripts ;
 875
 876 # Generate some data for debugging strange kallsyms problems
 877 debug_kallsyms: .tmp_map$(last_kallsyms)
 878
 879 .tmp_map%: .tmp_vmlinux% FORCE
 880         ($(OBJDUMP) -h $< | $(AWK) '/^ +[0-9]/{print $$4 " 0 " $$2}'; $(NM) $<) | sort > $@
 881
 882 .tmp_map3: .tmp_map2
 883
 884 .tmp_map2: .tmp_map1
 885
 886 endif # ifdef CONFIG_KALLSYMS
 887
 888 # Do modpost on a prelinked vmlinux. The finally linked vmlinux has
 889 # relevant sections renamed as per the linker script.
 890 quiet_cmd_vmlinux-modpost = LD      $@
 891       cmd_vmlinux-modpost = $(LD) $(LDFLAGS) -r -o $@                          \
 892          $(vmlinux-init) --start-group $(vmlinux-main) --end-group             \
 893          $(filter-out $(vmlinux-init) $(vmlinux-main) FORCE ,$^)
 894 define rule_vmlinux-modpost
 895         :
 896         +$(call cmd,vmlinux-modpost)
 897         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost $@
 898         $(Q)echo 'cmd_$@ := $(cmd_vmlinux-modpost)' > $(dot-target).cmd
 899 endef
 900
 901 # vmlinux image - including updated kernel symbols
 902 vmlinux: $(vmlinux-lds) $(vmlinux-init) $(vmlinux-main) vmlinux.o $(kallsyms.o) FORCE
 903 ifdef CONFIG_HEADERS_CHECK
 904         $(Q)$(MAKE) -f $(srctree)/Makefile headers_check
 905 endif
 906 ifdef CONFIG_SAMPLES
 907         $(Q)$(MAKE) $(build)=samples
 908 endif
 909 ifdef CONFIG_BUILD_DOCSRC
 910         $(Q)$(MAKE) $(build)=Documentation
 911 endif
 912         $(call vmlinux-modpost)
 913         $(call if_changed_rule,vmlinux__)
 914         $(Q)rm -f .old_version
 915
 916 # build vmlinux.o first to catch section mismatch errors early
 917 ifdef CONFIG_KALLSYMS
 918 .tmp_vmlinux1: vmlinux.o
 919 endif
 920
 921 modpost-init := $(filter-out init/built-in.o, $(vmlinux-init))
 922 vmlinux.o: $(modpost-init) $(vmlinux-main) FORCE
 923         $(call if_changed_rule,vmlinux-modpost)
 924
 925 # The actual objects are generated when descending,
 926 # make sure no implicit rule kicks in
 927 $(sort $(vmlinux-init) $(vmlinux-main)) $(vmlinux-lds): $(vmlinux-dirs) ;
 928
 929 # Handle descending into subdirectories listed in $(vmlinux-dirs)
 930 # Preset locale variables to speed up the build process. Limit locale
 931 # tweaks to this spot to avoid wrong language settings when running
 932 # make menuconfig etc.
 933 # Error messages still appears in the original language
 934
 935 PHONY += $(vmlinux-dirs)
 936 $(vmlinux-dirs): prepare scripts
 937         $(Q)$(MAKE) $(build)=$@
 938
 939 # Store (new) KERNELRELASE string in include/config/kernel.release
 940 include/config/kernel.release: include/config/auto.conf FORCE
 941         $(Q)rm -f $@
 942         $(Q)echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))" > $@
 943
 944
 945 # Things we need to do before we recursively start building the kernel
 946 # or the modules are listed in "prepare".
 947 # A multi level approach is used. prepareN is processed before prepareN-1.
 948 # archprepare is used in arch Makefiles and when processed asm symlink,
 949 # version.h and scripts_basic is processed / created.
 950
 951 # Listed in dependency order
 952 PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
 953
 954 # prepare3 is used to check if we are building in a separate output directory,
 955 # and if so do:
 956 # 1) Check that make has not been executed in the kernel src $(srctree)
 957 prepare3: include/config/kernel.release
 958 ifneq ($(KBUILD_SRC),)
 959         @$(kecho) '  Using $(srctree) as source for kernel'
 960         $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
 961                 echo "  $(srctree) is not clean, please run 'make mrproper'";\
 962                 echo "  in the '$(srctree)' directory.";\
 963                 /bin/false; \
 964         fi;
 965 endif
 966
 967 # prepare2 creates a makefile if using a separate output directory
 968 prepare2: prepare3 outputmakefile asm-generic
 969
 970 prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \
 971                    include/config/auto.conf
 972         $(cmd_crmodverdir)
 973
 974 archprepare: prepare1 scripts_basic
 975
 976 prepare0: archprepare FORCE
 977         $(Q)$(MAKE) $(build)=.
 978         $(Q)$(MAKE) $(build)=. missing-syscalls
 979
 980 # All the preparing..
 981 prepare: prepare0
 982
 983 # Generate some files
 984 # ---------------------------------------------------------------------------
 985
 986 # KERNELRELEASE can change from a few different places, meaning version.h
 987 # needs to be updated, so this check is forced on all builds
 988
 989 uts_len := 64
 990 define filechk_utsrelease.h
 991         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
 992           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
 993           exit 1;                                                         \
 994         fi;                                                               \
 995         (echo \#define UTS_RELEASE \"$(KERNELRELEASE)\";)
 996 endef
 997
 998 define filechk_version.h
 999         (echo \#define LINUX_VERSION_CODE $(shell                             \
1000         expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL));     \
1001         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';)
1002 endef
1003
1004 include/linux/version.h: $(srctree)/Makefile FORCE
1005         $(call filechk,version.h)
1006
1007 include/generated/utsrelease.h: include/config/kernel.release FORCE
1008         $(call filechk,utsrelease.h)
1009
1010 PHONY += headerdep
1011 headerdep:
1012         $(Q)find include/ -name '*.h' | xargs --max-args 1 scripts/headerdep.pl
1013
1014 # ---------------------------------------------------------------------------
1015
1016 PHONY += depend dep
1017 depend dep:
1018         @echo '*** Warning: make $@ is unnecessary now.'
1019
1020 # ---------------------------------------------------------------------------
1021 # Firmware install
1022 INSTALL_FW_PATH=$(INSTALL_MOD_PATH)/lib/firmware
1023 export INSTALL_FW_PATH
1024
1025 PHONY += firmware_install
1026 firmware_install: FORCE
1027         @mkdir -p $(objtree)/firmware
1028         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_install
1029
1030 # ---------------------------------------------------------------------------
1031 # Kernel headers
1032
1033 #Default location for installed headers
1034 export INSTALL_HDR_PATH = $(objtree)/usr
1035
1036 hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
1037
1038 # If we do an all arch process set dst to asm-$(hdr-arch)
1039 hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
1040
1041 PHONY += __headers
1042 __headers: include/linux/version.h scripts_basic asm-generic FORCE
1043         $(Q)$(MAKE) $(build)=scripts build_unifdef
1044
1045 PHONY += headers_install_all
1046 headers_install_all:
1047         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh install
1048
1049 PHONY += headers_install
1050 headers_install: __headers
1051         $(if $(wildcard $(srctree)/arch/$(hdr-arch)/include/asm/Kbuild),, \
1052         $(error Headers not exportable for the $(SRCARCH) architecture))
1053         $(Q)$(MAKE) $(hdr-inst)=include
1054         $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/asm $(hdr-dst)
1055
1056 PHONY += headers_check_all
1057 headers_check_all: headers_install_all
1058         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/headers.sh check
1059
1060 PHONY += headers_check
1061 headers_check: headers_install
1062         $(Q)$(MAKE) $(hdr-inst)=include HDRCHECK=1
1063         $(Q)$(MAKE) $(hdr-inst)=arch/$(hdr-arch)/include/asm $(hdr-dst) HDRCHECK=1
1064
1065 # ---------------------------------------------------------------------------
1066 # Modules
1067
1068 ifdef CONFIG_MODULES
1069
1070 # By default, build modules as well
1071
1072 all: modules
1073
1074 #       Build modules
1075 #
1076 #       A module can be listed more than once in obj-m resulting in
1077 #       duplicate lines in modules.order files.  Those are removed
1078 #       using awk while concatenating to the final file.
1079
1080 PHONY += modules
1081 modules: $(vmlinux-dirs) $(if $(KBUILD_BUILTIN),vmlinux) modules.builtin
1082         $(Q)$(AWK) '!x[$$0]++' $(vmlinux-dirs:%=$(objtree)/%/modules.order) > $(objtree)/modules.order
1083         @$(kecho) '  Building modules, stage 2.';
1084         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1085         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modbuild
1086
1087 modules.builtin: $(vmlinux-dirs:%=%/modules.builtin)
1088         $(Q)$(AWK) '!x[$$0]++' $^ > $(objtree)/modules.builtin
1089
1090 %/modules.builtin: include/config/auto.conf
1091         $(Q)$(MAKE) $(modbuiltin)=$*
1092
1093
1094 # Target to prepare building external modules
1095 PHONY += modules_prepare
1096 modules_prepare: prepare scripts
1097
1098 # Target to install modules
1099 PHONY += modules_install
1100 modules_install: _modinst_ _modinst_post
1101
1102 PHONY += _modinst_
1103 _modinst_:
1104         @if [ -z "`$(DEPMOD) -V 2>/dev/null | grep module-init-tools`" ]; then \
1105                 echo "Warning: you may need to install module-init-tools"; \
1106                 echo "See http://www.codemonkey.org.uk/docs/post-halloween-2.6.txt";\
1107                 sleep 1; \
1108         fi
1109         @rm -rf $(MODLIB)/kernel
1110         @rm -f $(MODLIB)/source
1111         @mkdir -p $(MODLIB)/kernel
1112         @ln -s $(srctree) $(MODLIB)/source
1113         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1114                 rm -f $(MODLIB)/build ; \
1115                 ln -s $(objtree) $(MODLIB)/build ; \
1116         fi
1117         @cp -f $(objtree)/modules.order $(MODLIB)/
1118         @cp -f $(objtree)/modules.builtin $(MODLIB)/
1119         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1120
1121 # This depmod is only for convenience to give the initial
1122 # boot a modules.dep even before / is mounted read-write.  However the
1123 # boot script depmod is the master version.
1124 PHONY += _modinst_post
1125 _modinst_post: _modinst_
1126         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.fwinst obj=firmware __fw_modinst
1127         $(call cmd,depmod)
1128
1129 else # CONFIG_MODULES
1130
1131 # Modules not configured
1132 # ---------------------------------------------------------------------------
1133
1134 modules modules_install: FORCE
1135         @echo
1136         @echo "The present kernel configuration has modules disabled."
1137         @echo "Type 'make config' and enable loadable module support."
1138         @echo "Then build a kernel with module support enabled."
1139         @echo
1140         @exit 1
1141
1142 endif # CONFIG_MODULES
1143
1144 ###
1145 # Cleaning is done on three levels.
1146 # make clean     Delete most generated files
1147 #                Leave enough to build external modules
1148 # make mrproper  Delete the current configuration, and all generated files
1149 # make distclean Remove editor backup files, patch leftover files and the like
1150
1151 # Directories & files removed with 'make clean'
1152 CLEAN_DIRS  += $(MODVERDIR)
1153 CLEAN_FILES +=  vmlinux System.map \
1154                 .tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map
1155
1156 # Directories & files removed with 'make mrproper'
1157 MRPROPER_DIRS  += include/config usr/include include/generated          \
1158                   arch/*/include/generated
1159 MRPROPER_FILES += .config .config.old .version .old_version             \
1160                   include/linux/version.h                               \
1161                   Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1162
1163 # clean - Delete most, but leave enough to build external modules
1164 #
1165 clean: rm-dirs  := $(CLEAN_DIRS)
1166 clean: rm-files := $(CLEAN_FILES)
1167 clean-dirs      := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation)
1168
1169 PHONY += $(clean-dirs) clean archclean
1170 $(clean-dirs):
1171         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1172
1173 clean: archclean
1174
1175 # mrproper - Delete all generated files, including .config
1176 #
1177 mrproper: rm-dirs  := $(wildcard $(MRPROPER_DIRS))
1178 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1179 mrproper-dirs      := $(addprefix _mrproper_,Documentation/DocBook scripts)
1180
1181 PHONY += $(mrproper-dirs) mrproper archmrproper
1182 $(mrproper-dirs):
1183         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1184
1185 mrproper: clean archmrproper $(mrproper-dirs)
1186         $(call cmd,rmdirs)
1187         $(call cmd,rmfiles)
1188
1189 # distclean
1190 #
1191 PHONY += distclean
1192
1193 distclean: mrproper
1194         @find $(srctree) $(RCS_FIND_IGNORE) \
1195                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1196                 -o -name '*.bak' -o -name '#*#' -o -name '.*.orig' \
1197                 -o -name '.*.rej' -o -size 0 \
1198                 -o -name '*%' -o -name '.*.cmd' -o -name 'core' \) \
1199                 -type f -print | xargs rm -f
1200
1201
1202 # Packaging of the kernel to various formats
1203 # ---------------------------------------------------------------------------
1204 # rpm target kept for backward compatibility
1205 package-dir     := $(srctree)/scripts/package
1206
1207 %src-pkg: FORCE
1208         $(Q)$(MAKE) $(build)=$(package-dir) $@
1209 %pkg: include/config/kernel.release FORCE
1210         $(Q)$(MAKE) $(build)=$(package-dir) $@
1211 rpm: include/config/kernel.release FORCE
1212         $(Q)$(MAKE) $(build)=$(package-dir) $@
1213
1214
1215 # Brief documentation of the typical targets used
1216 # ---------------------------------------------------------------------------
1217
1218 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1219 boards := $(notdir $(boards))
1220 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1221 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1222
1223 help:
1224         @echo  'Cleaning targets:'
1225         @echo  '  clean           - Remove most generated files but keep the config and'
1226         @echo  '                    enough build support to build external modules'
1227         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1228         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1229         @echo  ''
1230         @echo  'Configuration targets:'
1231         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1232         @echo  ''
1233         @echo  'Other generic targets:'
1234         @echo  '  all             - Build all targets marked with [*]'
1235         @echo  '* vmlinux         - Build the bare kernel'
1236         @echo  '* modules         - Build all modules'
1237         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1238         @echo  '  firmware_install- Install all firmware to INSTALL_FW_PATH'
1239         @echo  '                    (default: $$(INSTALL_MOD_PATH)/lib/firmware)'
1240         @echo  '  dir/            - Build all files in dir and below'
1241         @echo  '  dir/file.[oisS] - Build specified target only'
1242         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1243         @echo  '                    (requires a recent binutils and recent build (System.map))'
1244         @echo  '  dir/file.ko     - Build module including final link'
1245         @echo  '  modules_prepare - Set up for building external modules'
1246         @echo  '  tags/TAGS       - Generate tags file for editors'
1247         @echo  '  cscope          - Generate cscope index'
1248         @echo  '  gtags           - Generate GNU GLOBAL index'
1249         @echo  '  kernelrelease   - Output the release version string'
1250         @echo  '  kernelversion   - Output the version stored in Makefile'
1251         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1252          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1253          echo  ''
1254         @echo  'Static analysers'
1255         @echo  '  checkstack      - Generate a list of stack hogs'
1256         @echo  '  namespacecheck  - Name space analysis on compiled kernel'
1257         @echo  '  versioncheck    - Sanity check on version.h usage'
1258         @echo  '  includecheck    - Check for duplicate included header files'
1259         @echo  '  export_report   - List the usages of all exported symbols'
1260         @echo  '  headers_check   - Sanity check on exported headers'
1261         @echo  '  headerdep       - Detect inclusion cycles in headers'
1262         @$(MAKE) -f $(srctree)/scripts/Makefile.help checker-help
1263         @echo  ''
1264         @echo  'Kernel packaging:'
1265         @$(MAKE) $(build)=$(package-dir) help
1266         @echo  ''
1267         @echo  'Documentation targets:'
1268         @$(MAKE) -f $(srctree)/Documentation/DocBook/Makefile dochelp
1269         @echo  ''
1270         @echo  'Architecture specific targets ($(SRCARCH)):'
1271         @$(if $(archhelp),$(archhelp),\
1272                 echo '  No architecture specific help defined for $(SRCARCH)')
1273         @echo  ''
1274         @$(if $(boards), \
1275                 $(foreach b, $(boards), \
1276                 printf "  %-24s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1277                 echo '')
1278         @$(if $(board-dirs), \
1279                 $(foreach b, $(board-dirs), \
1280                 printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1281                 printf "  %-16s - Show all of the above\\n" help-boards; \
1282                 echo '')
1283
1284         @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1285         @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1286         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1287         @echo  '  make C=1   [targets] Check all c source with $$CHECK (sparse by default)'
1288         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1289         @echo  '  make W=n   [targets] Enable extra gcc checks, n=1,2,3 where'
1290         @echo  '                1: warnings which may be relevant and do not occur too often'
1291         @echo  '                2: warnings which occur quite often but may still be relevant'
1292         @echo  '                3: more obscure warnings, can most likely be ignored'
1293         @echo  '                Multiple levels can be combined with W=12 or W=123'
1294         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1295         @echo  ''
1296         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1297         @echo  'For further info see the ./README file'
1298
1299
1300 help-board-dirs := $(addprefix help-,$(board-dirs))
1301
1302 help-boards: $(help-board-dirs)
1303
1304 boards-per-dir = $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig))
1305
1306 $(help-board-dirs): help-%:
1307         @echo  'Architecture specific targets ($(SRCARCH) $*):'
1308         @$(if $(boards-per-dir), \
1309                 $(foreach b, $(boards-per-dir), \
1310                 printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1311                 echo '')
1312
1313
1314 # Documentation targets
1315 # ---------------------------------------------------------------------------
1316 %docs: scripts_basic FORCE
1317         $(Q)$(MAKE) $(build)=scripts build_docproc
1318         $(Q)$(MAKE) $(build)=Documentation/DocBook $@
1319
1320 else # KBUILD_EXTMOD
1321
1322 ###
1323 # External module support.
1324 # When building external modules the kernel used as basis is considered
1325 # read-only, and no consistency checks are made and the make
1326 # system is not used on the basis kernel. If updates are required
1327 # in the basis kernel ordinary make commands (without M=...) must
1328 # be used.
1329 #
1330 # The following are the only valid targets when building external
1331 # modules.
1332 # make M=dir clean     Delete all automatically generated files
1333 # make M=dir modules   Make all modules in specified dir
1334 # make M=dir           Same as 'make M=dir modules'
1335 # make M=dir modules_install
1336 #                      Install the modules built in the module directory
1337 #                      Assumes install directory is already created
1338
1339 # We are always building modules
1340 KBUILD_MODULES := 1
1341 PHONY += crmodverdir
1342 crmodverdir:
1343         $(cmd_crmodverdir)
1344
1345 PHONY += $(objtree)/Module.symvers
1346 $(objtree)/Module.symvers:
1347         @test -e $(objtree)/Module.symvers || ( \
1348         echo; \
1349         echo "  WARNING: Symbol version dump $(objtree)/Module.symvers"; \
1350         echo "           is missing; modules will have no dependencies and modversions."; \
1351         echo )
1352
1353 module-dirs := $(addprefix _module_,$(KBUILD_EXTMOD))
1354 PHONY += $(module-dirs) modules
1355 $(module-dirs): crmodverdir $(objtree)/Module.symvers
1356         $(Q)$(MAKE) $(build)=$(patsubst _module_%,%,$@)
1357
1358 modules: $(module-dirs)
1359         @$(kecho) '  Building modules, stage 2.';
1360         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1361
1362 PHONY += modules_install
1363 modules_install: _emodinst_ _emodinst_post
1364
1365 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1366 PHONY += _emodinst_
1367 _emodinst_:
1368         $(Q)mkdir -p $(MODLIB)/$(install-dir)
1369         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1370
1371 PHONY += _emodinst_post
1372 _emodinst_post: _emodinst_
1373         $(call cmd,depmod)
1374
1375 clean-dirs := $(addprefix _clean_,$(KBUILD_EXTMOD))
1376
1377 PHONY += $(clean-dirs) clean
1378 $(clean-dirs):
1379         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1380
1381 clean:  rm-dirs := $(MODVERDIR)
1382 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers
1383
1384 help:
1385         @echo  '  Building external modules.'
1386         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1387         @echo  ''
1388         @echo  '  modules         - default target, build the module(s)'
1389         @echo  '  modules_install - install the module'
1390         @echo  '  clean           - remove generated files in module directory only'
1391         @echo  ''
1392
1393 # Dummies...
1394 PHONY += prepare scripts
1395 prepare: ;
1396 scripts: ;
1397 endif # KBUILD_EXTMOD
1398
1399 clean: $(clean-dirs)
1400         $(call cmd,rmdirs)
1401         $(call cmd,rmfiles)
1402         @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1403                 \( -name '*.[oas]' -o -name '*.ko' -o -name '.*.cmd' \
1404                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1405                 -o -name '*.symtypes' -o -name 'modules.order' \
1406                 -o -name modules.builtin -o -name '.tmp_*.o.*' \
1407                 -o -name '*.gcno' \) -type f -print | xargs rm -f
1408
1409 # Generate tags for editors
1410 # ---------------------------------------------------------------------------
1411 quiet_cmd_tags = GEN     $@
1412       cmd_tags = $(CONFIG_SHELL) $(srctree)/scripts/tags.sh $@
1413
1414 tags TAGS cscope gtags: FORCE
1415         $(call cmd,tags)
1416
1417 # Scripts to check various things for consistency
1418 # ---------------------------------------------------------------------------
1419
1420 includecheck:
1421         find * $(RCS_FIND_IGNORE) \
1422                 -name '*.[hcS]' -type f -print | sort \
1423                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1424
1425 versioncheck:
1426         find * $(RCS_FIND_IGNORE) \
1427                 -name '*.[hcS]' -type f -print | sort \
1428                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1429
1430 coccicheck:
1431         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/$@
1432
1433 namespacecheck:
1434         $(PERL) $(srctree)/scripts/namespace.pl
1435
1436 export_report:
1437         $(PERL) $(srctree)/scripts/export_report.pl
1438
1439 endif #ifeq ($(config-targets),1)
1440 endif #ifeq ($(mixed-targets),1)
1441
1442 PHONY += checkstack kernelrelease kernelversion
1443
1444 # UML needs a little special treatment here.  It wants to use the host
1445 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1446 # else wants $(ARCH), including people doing cross-builds, which means
1447 # that $(SUBARCH) doesn't work here.
1448 ifeq ($(ARCH), um)
1449 CHECKSTACK_ARCH := $(SUBARCH)
1450 else
1451 CHECKSTACK_ARCH := $(ARCH)
1452 endif
1453 checkstack:
1454         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1455         $(PERL) $(src)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1456
1457 kernelrelease:
1458         @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1459
1460 kernelversion:
1461         @echo $(KERNELVERSION)
1462
1463 # Single targets
1464 # ---------------------------------------------------------------------------
1465 # Single targets are compatible with:
1466 # - build with mixed source and output
1467 # - build with separate output dir 'make O=...'
1468 # - external modules
1469 #
1470 #  target-dir => where to store outputfile
1471 #  build-dir  => directory in kernel source tree to use
1472
1473 ifeq ($(KBUILD_EXTMOD),)
1474         build-dir  = $(patsubst %/,%,$(dir $@))
1475         target-dir = $(dir $@)
1476 else
1477         zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
1478         build-dir  = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
1479         target-dir = $(if $(KBUILD_EXTMOD),$(dir $<),$(dir $@))
1480 endif
1481
1482 %.s: %.c prepare scripts FORCE
1483         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1484 %.i: %.c prepare scripts FORCE
1485         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1486 %.o: %.c prepare scripts FORCE
1487         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1488 %.lst: %.c prepare scripts FORCE
1489         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1490 %.s: %.S prepare scripts FORCE
1491         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1492 %.o: %.S prepare scripts FORCE
1493         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1494 %.symtypes: %.c prepare scripts FORCE
1495         $(Q)$(MAKE) $(build)=$(build-dir) $(target-dir)$(notdir $@)
1496
1497 # Modules
1498 /: prepare scripts FORCE
1499         $(cmd_crmodverdir)
1500         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1501         $(build)=$(build-dir)
1502 %/: prepare scripts FORCE
1503         $(cmd_crmodverdir)
1504         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
1505         $(build)=$(build-dir)
1506 %.ko: prepare scripts FORCE
1507         $(cmd_crmodverdir)
1508         $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1)   \
1509         $(build)=$(build-dir) $(@:.ko=.o)
1510         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1511
1512 # FIXME Should go into a make.lib or something
1513 # ===========================================================================
1514
1515 quiet_cmd_rmdirs = $(if $(wildcard $(rm-dirs)),CLEAN   $(wildcard $(rm-dirs)))
1516       cmd_rmdirs = rm -rf $(rm-dirs)
1517
1518 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1519       cmd_rmfiles = rm -f $(rm-files)
1520
1521 # Run depmod only if we have System.map and depmod is executable
1522 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
1523       cmd_depmod = \
1524         if [ -r System.map -a -x $(DEPMOD) ]; then                              \
1525                 $(DEPMOD) -ae -F System.map                                     \
1526                 $(if $(strip $(INSTALL_MOD_PATH)), -b $(INSTALL_MOD_PATH) )     \
1527                 $(KERNELRELEASE);                                               \
1528         fi
1529
1530 # Create temporary dir for module support files
1531 # clean it up only when building all modules
1532 cmd_crmodverdir = $(Q)mkdir -p $(MODVERDIR) \
1533                   $(if $(KBUILD_MODULES),; rm -f $(MODVERDIR)/*)
1534
1535 a_flags = -Wp,-MD,$(depfile) $(KBUILD_AFLAGS) $(AFLAGS_KERNEL) \
1536           $(KBUILD_AFLAGS_KERNEL)                              \
1537           $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(KBUILD_CPPFLAGS) \
1538           $(modkern_aflags) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o)
1539
1540 quiet_cmd_as_o_S = AS      $@
1541 cmd_as_o_S       = $(CC) $(a_flags) -c -o $@ $<
1542
1543 # read all saved command lines
1544
1545 targets := $(wildcard $(sort $(targets)))
1546 cmd_files := $(wildcard .*.cmd $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
1547
1548 ifneq ($(cmd_files),)
1549   $(cmd_files): ;       # Do not try to update included dependency files
1550   include $(cmd_files)
1551 endif
1552
1553 # Shorthand for $(Q)$(MAKE) -f scripts/Makefile.clean obj=dir
1554 # Usage:
1555 # $(Q)$(MAKE) $(clean)=dir
1556 clean := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.clean obj
1557
1558 endif   # skip-makefile
1559
1560 PHONY += FORCE
1561 FORCE:
1562
1563 # Declare the contents of the .PHONY variable as phony.  We keep that
1564 # information in a variable so we can use it in if_changed and friends.
1565 .PHONY: $(PHONY)