Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 VERSION = 5
   3 PATCHLEVEL = 10
   4 SUBLEVEL = 35
   5 EXTRAVERSION =
   6 NAME = Dare mighty things
   7
   8 # *DOCUMENTATION*
   9 # To see a list of typical targets execute "make help"
  10 # More info can be located in ./README
  11 # Comments in this file are targeted only to the developer, do not
  12 # expect to learn how to build the kernel reading this file.
  13
  14 $(if $(filter __%, $(MAKECMDGOALS)), \
  15         $(error targets prefixed with '__' are only for internal use))
  16
  17 # That's our default target when none is given on the command line
  18 PHONY := __all
  19 __all:
  20
  21 # We are using a recursive build, so we need to do a little thinking
  22 # to get the ordering right.
  23 #
  24 # Most importantly: sub-Makefiles should only ever modify files in
  25 # their own directory. If in some directory we have a dependency on
  26 # a file in another dir (which doesn't happen often, but it's often
  27 # unavoidable when linking the built-in.a targets which finally
  28 # turn into vmlinux), we will call a sub make in that other dir, and
  29 # after that we are sure that everything which is in that other dir
  30 # is now up to date.
  31 #
  32 # The only cases where we need to modify files which have global
  33 # effects are thus separated out and done before the recursive
  34 # descending is started. They are now explicitly listed as the
  35 # prepare rule.
  36
  37 ifneq ($(sub_make_done),1)
  38
  39 # Do not use make's built-in rules and variables
  40 # (this increases performance and avoids hard-to-debug behaviour)
  41 MAKEFLAGS += -rR
  42
  43 # Avoid funny character set dependencies
  44 unexport LC_ALL
  45 LC_COLLATE=C
  46 LC_NUMERIC=C
  47 export LC_COLLATE LC_NUMERIC
  48
  49 # Avoid interference with shell env settings
  50 unexport GREP_OPTIONS
  51
  52 # Beautify output
  53 # ---------------------------------------------------------------------------
  54 #
  55 # Normally, we echo the whole command before executing it. By making
  56 # that echo $($(quiet)$(cmd)), we now have the possibility to set
  57 # $(quiet) to choose other forms of output instead, e.g.
  58 #
  59 #         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
  60 #         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
  61 #
  62 # If $(quiet) is empty, the whole command will be printed.
  63 # If it is set to "quiet_", only the short version will be printed.
  64 # If it is set to "silent_", nothing will be printed at all, since
  65 # the variable $(silent_cmd_cc_o_c) doesn't exist.
  66 #
  67 # A simple variant is to prefix commands with $(Q) - that's useful
  68 # for commands that shall be hidden in non-verbose mode.
  69 #
  70 #       $(Q)ln $@ :<
  71 #
  72 # If KBUILD_VERBOSE equals 0 then the above command will be hidden.
  73 # If KBUILD_VERBOSE equals 1 then the above command is displayed.
  74 # If KBUILD_VERBOSE equals 2 then give the reason why each target is rebuilt.
  75 #
  76 # To put more focus on warnings, be less verbose as default
  77 # Use 'make V=1' to see the full commands
  78
  79 ifeq ("$(origin V)", "command line")
  80   KBUILD_VERBOSE = $(V)
  81 endif
  82 ifndef KBUILD_VERBOSE
  83   KBUILD_VERBOSE = 0
  84 endif
  85
  86 ifeq ($(KBUILD_VERBOSE),1)
  87   quiet =
  88   Q =
  89 else
  90   quiet=quiet_
  91   Q = @
  92 endif
  93
  94 # If the user is running make -s (silent mode), suppress echoing of
  95 # commands
  96
  97 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
  98   quiet=silent_
  99 endif
 100
 101 export quiet Q KBUILD_VERBOSE
 102
 103 # Kbuild will save output files in the current working directory.
 104 # This does not need to match to the root of the kernel source tree.
 105 #
 106 # For example, you can do this:
 107 #
 108 #  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
 109 #
 110 # If you want to save output files in a different location, there are
 111 # two syntaxes to specify it.
 112 #
 113 # 1) O=
 114 # Use "make O=dir/to/store/output/files/"
 115 #
 116 # 2) Set KBUILD_OUTPUT
 117 # Set the environment variable KBUILD_OUTPUT to point to the output directory.
 118 # export KBUILD_OUTPUT=dir/to/store/output/files/; make
 119 #
 120 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
 121 # variable.
 122
 123 # Do we want to change the working directory?
 124 ifeq ("$(origin O)", "command line")
 125   KBUILD_OUTPUT := $(O)
 126 endif
 127
 128 ifneq ($(KBUILD_OUTPUT),)
 129 # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
 130 # expand a shell special character '~'. We use a somewhat tedious way here.
 131 abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
 132 $(if $(abs_objtree),, \
 133      $(error failed to create output directory "$(KBUILD_OUTPUT)"))
 134
 135 # $(realpath ...) resolves symlinks
 136 abs_objtree := $(realpath $(abs_objtree))
 137 else
 138 abs_objtree := $(CURDIR)
 139 endif # ifneq ($(KBUILD_OUTPUT),)
 140
 141 ifeq ($(abs_objtree),$(CURDIR))
 142 # Suppress "Entering directory ..." unless we are changing the work directory.
 143 MAKEFLAGS += --no-print-directory
 144 else
 145 need-sub-make := 1
 146 endif
 147
 148 abs_srctree := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
 149
 150 ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
 151 $(error source directory cannot contain spaces or colons)
 152 endif
 153
 154 ifneq ($(abs_srctree),$(abs_objtree))
 155 # Look for make include files relative to root of kernel src
 156 #
 157 # This does not become effective immediately because MAKEFLAGS is re-parsed
 158 # once after the Makefile is read. We need to invoke sub-make.
 159 MAKEFLAGS += --include-dir=$(abs_srctree)
 160 need-sub-make := 1
 161 endif
 162
 163 this-makefile := $(lastword $(MAKEFILE_LIST))
 164
 165 ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 166 # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
 167 # We need to invoke sub-make to avoid implicit rules in the top Makefile.
 168 need-sub-make := 1
 169 # Cancel implicit rules for this Makefile.
 170 $(this-makefile): ;
 171 endif
 172
 173 export abs_srctree abs_objtree
 174 export sub_make_done := 1
 175
 176 ifeq ($(need-sub-make),1)
 177
 178 PHONY += $(MAKECMDGOALS) __sub-make
 179
 180 $(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 181         @:
 182
 183 # Invoke a second make in the output directory, passing relevant variables
 184 __sub-make:
 185         $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 186
 187 endif # need-sub-make
 188 endif # sub_make_done
 189
 190 # We process the rest of the Makefile if this is the final invocation of make
 191 ifeq ($(need-sub-make),)
 192
 193 # Do not print "Entering directory ...",
 194 # but we want to display it when entering to the output directory
 195 # so that IDEs/editors are able to understand relative filenames.
 196 MAKEFLAGS += --no-print-directory
 197
 198 # Call a source code checker (by default, "sparse") as part of the
 199 # C compilation.
 200 #
 201 # Use 'make C=1' to enable checking of only re-compiled files.
 202 # Use 'make C=2' to enable checking of *all* source files, regardless
 203 # of whether they are re-compiled or not.
 204 #
 205 # See the file "Documentation/dev-tools/sparse.rst" for more details,
 206 # including where to get the "sparse" utility.
 207
 208 ifeq ("$(origin C)", "command line")
 209   KBUILD_CHECKSRC = $(C)
 210 endif
 211 ifndef KBUILD_CHECKSRC
 212   KBUILD_CHECKSRC = 0
 213 endif
 214
 215 # Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
 216 # directory of external module to build. Setting M= takes precedence.
 217 ifeq ("$(origin M)", "command line")
 218   KBUILD_EXTMOD := $(M)
 219 endif
 220
 221 $(if $(word 2, $(KBUILD_EXTMOD)), \
 222         $(error building multiple external modules is not supported))
 223
 224 export KBUILD_CHECKSRC KBUILD_EXTMOD
 225
 226 extmod-prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
 227
 228 ifeq ($(abs_srctree),$(abs_objtree))
 229         # building in the source tree
 230         srctree := .
 231         building_out_of_srctree :=
 232 else
 233         ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
 234                 # building in a subdirectory of the source tree
 235                 srctree := ..
 236         else
 237                 srctree := $(abs_srctree)
 238         endif
 239         building_out_of_srctree := 1
 240 endif
 241
 242 ifneq ($(KBUILD_ABS_SRCTREE),)
 243 srctree := $(abs_srctree)
 244 endif
 245
 246 objtree         := .
 247 VPATH           := $(srctree)
 248
 249 export building_out_of_srctree srctree objtree VPATH
 250
 251 # To make sure we do not include .config for any of the *config targets
 252 # catch them early, and hand them over to scripts/kconfig/Makefile
 253 # It is allowed to specify more targets when calling make, including
 254 # mixing *config targets and build targets.
 255 # For example 'make oldconfig all'.
 256 # Detect when mixed targets is specified, and make a second invocation
 257 # of make so .config is not included in this case either (for *config).
 258
 259 version_h := include/generated/uapi/linux/version.h
 260 old_version_h := include/linux/version.h
 261
 262 clean-targets := %clean mrproper cleandocs
 263 no-dot-config-targets := $(clean-targets) \
 264                          cscope gtags TAGS tags help% %docs check% coccicheck \
 265                          $(version_h) headers headers_% archheaders archscripts \
 266                          %asm-generic kernelversion %src-pkg dt_binding_check \
 267                          outputmakefile
 268 no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
 269                           image_name
 270 single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
 271
 272 config-build    :=
 273 mixed-build     :=
 274 need-config     := 1
 275 may-sync-config := 1
 276 single-build    :=
 277
 278 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 279         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 280                 need-config :=
 281         endif
 282 endif
 283
 284 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 285         ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 286                 may-sync-config :=
 287         endif
 288 endif
 289
 290 ifneq ($(KBUILD_EXTMOD),)
 291         may-sync-config :=
 292 endif
 293
 294 ifeq ($(KBUILD_EXTMOD),)
 295         ifneq ($(filter %config,$(MAKECMDGOALS)),)
 296                 config-build := 1
 297                 ifneq ($(words $(MAKECMDGOALS)),1)
 298                         mixed-build := 1
 299                 endif
 300         endif
 301 endif
 302
 303 # We cannot build single targets and the others at the same time
 304 ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 305         single-build := 1
 306         ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 307                 mixed-build := 1
 308         endif
 309 endif
 310
 311 # For "make -j clean all", "make -j mrproper defconfig all", etc.
 312 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 313         ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 314                 mixed-build := 1
 315         endif
 316 endif
 317
 318 # install and modules_install need also be processed one by one
 319 ifneq ($(filter install,$(MAKECMDGOALS)),)
 320         ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 321                 mixed-build := 1
 322         endif
 323 endif
 324
 325 ifdef mixed-build
 326 # ===========================================================================
 327 # We're called with mixed targets (*config and build targets).
 328 # Handle them one by one.
 329
 330 PHONY += $(MAKECMDGOALS) __build_one_by_one
 331
 332 $(MAKECMDGOALS): __build_one_by_one
 333         @:
 334
 335 __build_one_by_one:
 336         $(Q)set -e; \
 337         for i in $(MAKECMDGOALS); do \
 338                 $(MAKE) -f $(srctree)/Makefile $$i; \
 339         done
 340
 341 else # !mixed-build
 342
 343 include scripts/Kbuild.include
 344
 345 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 346 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 347 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 348 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 349
 350 include scripts/subarch.include
 351
 352 # Cross compiling and selecting different set of gcc/bin-utils
 353 # ---------------------------------------------------------------------------
 354 #
 355 # When performing cross compilation for other architectures ARCH shall be set
 356 # to the target architecture. (See arch/* for the possibilities).
 357 # ARCH can be set during invocation of make:
 358 # make ARCH=ia64
 359 # Another way is to have ARCH set in the environment.
 360 # The default ARCH is the host where make is executed.
 361
 362 # CROSS_COMPILE specify the prefix used for all executables used
 363 # during compilation. Only gcc and related bin-utils executables
 364 # are prefixed with $(CROSS_COMPILE).
 365 # CROSS_COMPILE can be set on the command line
 366 # make CROSS_COMPILE=ia64-linux-
 367 # Alternatively CROSS_COMPILE can be set in the environment.
 368 # Default value for CROSS_COMPILE is not to prefix executables
 369 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 370 ARCH            ?= $(SUBARCH)
 371
 372 # Architecture as present in compile.h
 373 UTS_MACHINE     := $(ARCH)
 374 SRCARCH         := $(ARCH)
 375
 376 # Additional ARCH settings for x86
 377 ifeq ($(ARCH),i386)
 378         SRCARCH := x86
 379 endif
 380 ifeq ($(ARCH),x86_64)
 381         SRCARCH := x86
 382 endif
 383
 384 # Additional ARCH settings for sparc
 385 ifeq ($(ARCH),sparc32)
 386        SRCARCH := sparc
 387 endif
 388 ifeq ($(ARCH),sparc64)
 389        SRCARCH := sparc
 390 endif
 391
 392 # Additional ARCH settings for sh
 393 ifeq ($(ARCH),sh64)
 394        SRCARCH := sh
 395 endif
 396
 397 KCONFIG_CONFIG  ?= .config
 398 export KCONFIG_CONFIG
 399
 400 # Default file for 'make defconfig'. This may be overridden by arch-Makefile.
 401 export KBUILD_DEFCONFIG := defconfig
 402
 403 # SHELL used by kbuild
 404 CONFIG_SHELL := sh
 405
 406 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 407 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 408 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 409
 410 ifneq ($(LLVM),)
 411 HOSTCC  = clang
 412 HOSTCXX = clang++
 413 else
 414 HOSTCC  = gcc
 415 HOSTCXX = g++
 416 endif
 417
 418 export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 419                               -O2 -fomit-frame-pointer -std=gnu89
 420 export KBUILD_USERLDFLAGS :=
 421
 422 KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 423 KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 424 KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 425 KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 426
 427 # Make variables (CC, etc...)
 428 CPP             = $(CC) -E
 429 ifneq ($(LLVM),)
 430 CC              = clang
 431 LD              = ld.lld
 432 AR              = llvm-ar
 433 NM              = llvm-nm
 434 OBJCOPY         = llvm-objcopy
 435 OBJDUMP         = llvm-objdump
 436 READELF         = llvm-readelf
 437 STRIP           = llvm-strip
 438 else
 439 CC              = $(CROSS_COMPILE)gcc
 440 LD              = $(CROSS_COMPILE)ld
 441 AR              = $(CROSS_COMPILE)ar
 442 NM              = $(CROSS_COMPILE)nm
 443 OBJCOPY         = $(CROSS_COMPILE)objcopy
 444 OBJDUMP         = $(CROSS_COMPILE)objdump
 445 READELF         = $(CROSS_COMPILE)readelf
 446 STRIP           = $(CROSS_COMPILE)strip
 447 endif
 448 PAHOLE          = pahole
 449 RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 450 LEX             = flex
 451 YACC            = bison
 452 AWK             = awk
 453 INSTALLKERNEL  := installkernel
 454 DEPMOD          = depmod
 455 PERL            = perl
 456 PYTHON          = python
 457 PYTHON3         = python3
 458 CHECK           = sparse
 459 BASH            = bash
 460 KGZIP           = gzip
 461 KBZIP2          = bzip2
 462 KLZOP           = lzop
 463 LZMA            = lzma
 464 LZ4             = lz4c
 465 XZ              = xz
 466 ZSTD            = zstd
 467
 468 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 469                   -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 470 NOSTDINC_FLAGS :=
 471 CFLAGS_MODULE   =
 472 AFLAGS_MODULE   =
 473 LDFLAGS_MODULE  =
 474 CFLAGS_KERNEL   =
 475 AFLAGS_KERNEL   =
 476 LDFLAGS_vmlinux =
 477
 478 # Use USERINCLUDE when you must reference the UAPI directories only.
 479 USERINCLUDE    := \
 480                 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 481                 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 482                 -I$(srctree)/include/uapi \
 483                 -I$(objtree)/include/generated/uapi \
 484                 -include $(srctree)/include/linux/kconfig.h
 485
 486 # Use LINUXINCLUDE when you must reference the include/ directory.
 487 # Needed to be compatible with the O= option
 488 LINUXINCLUDE    := \
 489                 -I$(srctree)/arch/$(SRCARCH)/include \
 490                 -I$(objtree)/arch/$(SRCARCH)/include/generated \
 491                 $(if $(building_out_of_srctree),-I$(srctree)/include) \
 492                 -I$(objtree)/include \
 493                 $(USERINCLUDE)
 494
 495 KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 496 KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 497                    -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 498                    -Werror=implicit-function-declaration -Werror=implicit-int \
 499                    -Werror=return-type -Wno-format-security \
 500                    -std=gnu89
 501 KBUILD_CPPFLAGS := -D__KERNEL__
 502 KBUILD_AFLAGS_KERNEL :=
 503 KBUILD_CFLAGS_KERNEL :=
 504 KBUILD_AFLAGS_MODULE  := -DMODULE
 505 KBUILD_CFLAGS_MODULE  := -DMODULE
 506 KBUILD_LDFLAGS_MODULE :=
 507 KBUILD_LDFLAGS :=
 508 CLANG_FLAGS :=
 509
 510 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
 511 export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 512 export PERL PYTHON PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 513 export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 514 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 515
 516 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 517 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 518 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 519 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 520 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 521
 522 # Files to ignore in find ... statements
 523
 524 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 525                           -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 526                           -prune -o
 527 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 528                          --exclude CVS --exclude .pc --exclude .hg --exclude .git
 529
 530 # ===========================================================================
 531 # Rules shared between *config targets and build targets
 532
 533 # Basic helpers built in scripts/basic/
 534 PHONY += scripts_basic
 535 scripts_basic:
 536         $(Q)$(MAKE) $(build)=scripts/basic
 537         $(Q)rm -f .tmp_quiet_recordmcount
 538
 539 PHONY += outputmakefile
 540 # Before starting out-of-tree build, make sure the source tree is clean.
 541 # outputmakefile generates a Makefile in the output directory, if using a
 542 # separate output directory. This allows convenient use of make in the
 543 # output directory.
 544 # At the same time when output Makefile generated, generate .gitignore to
 545 # ignore whole output directory
 546 outputmakefile:
 547 ifdef building_out_of_srctree
 548         $(Q)if [ -f $(srctree)/.config -o \
 549                  -d $(srctree)/include/config -o \
 550                  -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 551                 echo >&2 "***"; \
 552                 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 553                 echo >&2 "*** in $(abs_srctree)";\
 554                 echo >&2 "***"; \
 555                 false; \
 556         fi
 557         $(Q)ln -fsn $(srctree) source
 558         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
 559         $(Q)test -e .gitignore || \
 560         { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 561 endif
 562
 563 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
 564 ifneq ($(CROSS_COMPILE),)
 565 CLANG_FLAGS     += --target=$(notdir $(CROSS_COMPILE:%-=%))
 566 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
 567 CLANG_FLAGS     += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
 568 GCC_TOOLCHAIN   := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
 569 endif
 570 ifneq ($(GCC_TOOLCHAIN),)
 571 CLANG_FLAGS     += --gcc-toolchain=$(GCC_TOOLCHAIN)
 572 endif
 573 ifneq ($(LLVM_IAS),1)
 574 CLANG_FLAGS     += -no-integrated-as
 575 endif
 576 CLANG_FLAGS     += -Werror=unknown-warning-option
 577 KBUILD_CFLAGS   += $(CLANG_FLAGS)
 578 KBUILD_AFLAGS   += $(CLANG_FLAGS)
 579 export CLANG_FLAGS
 580 endif
 581
 582 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 583 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 584 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 585 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
 586 CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)
 587
 588 ifdef config-build
 589 # ===========================================================================
 590 # *config targets only - make sure prerequisites are updated, and descend
 591 # in scripts/kconfig to make the *config target
 592
 593 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 594 # KBUILD_DEFCONFIG may point out an alternative default configuration
 595 # used for 'make defconfig'
 596 include arch/$(SRCARCH)/Makefile
 597 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 598
 599 config: outputmakefile scripts_basic FORCE
 600         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 601
 602 %config: outputmakefile scripts_basic FORCE
 603         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 604
 605 else #!config-build
 606 # ===========================================================================
 607 # Build targets only - this includes vmlinux, arch specific targets, clean
 608 # targets and others. In general all targets except *config targets.
 609
 610 # If building an external module we do not care about the all: rule
 611 # but instead __all depend on modules
 612 PHONY += all
 613 ifeq ($(KBUILD_EXTMOD),)
 614 __all: all
 615 else
 616 __all: modules
 617 endif
 618
 619 # Decide whether to build built-in, modular, or both.
 620 # Normally, just do built-in.
 621
 622 KBUILD_MODULES :=
 623 KBUILD_BUILTIN := 1
 624
 625 # If we have only "make modules", don't compile built-in objects.
 626 ifeq ($(MAKECMDGOALS),modules)
 627   KBUILD_BUILTIN :=
 628 endif
 629
 630 # If we have "make <whatever> modules", compile modules
 631 # in addition to whatever we do anyway.
 632 # Just "make" or "make all" shall build modules as well
 633
 634 ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 635   KBUILD_MODULES := 1
 636 endif
 637
 638 ifeq ($(MAKECMDGOALS),)
 639   KBUILD_MODULES := 1
 640 endif
 641
 642 export KBUILD_MODULES KBUILD_BUILTIN
 643
 644 ifdef need-config
 645 include include/config/auto.conf
 646 endif
 647
 648 ifeq ($(KBUILD_EXTMOD),)
 649 # Objects we will link into vmlinux / subdirs we need to visit
 650 core-y          := init/ usr/
 651 drivers-y       := drivers/ sound/
 652 drivers-$(CONFIG_SAMPLES) += samples/
 653 drivers-y       += net/ virt/
 654 libs-y          := lib/
 655 endif # KBUILD_EXTMOD
 656
 657 # The all: target is the default when no target is given on the
 658 # command line.
 659 # This allow a user to issue only 'make' to build a kernel including modules
 660 # Defaults to vmlinux, but the arch makefile usually adds further targets
 661 all: vmlinux
 662
 663 CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage \
 664         $(call cc-option,-fno-tree-loop-im) \
 665         $(call cc-disable-warning,maybe-uninitialized,)
 666 export CFLAGS_GCOV
 667
 668 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 669 ifdef CONFIG_FUNCTION_TRACER
 670   CC_FLAGS_FTRACE := -pg
 671 endif
 672
 673 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
 674 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
 675 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
 676 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
 677 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
 678 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
 679 export RETPOLINE_CFLAGS
 680 export RETPOLINE_VDSO_CFLAGS
 681
 682 include arch/$(SRCARCH)/Makefile
 683
 684 ifdef need-config
 685 ifdef may-sync-config
 686 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 687 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 688 # because some architectures define CROSS_COMPILE there.
 689 include include/config/auto.conf.cmd
 690
 691 $(KCONFIG_CONFIG):
 692         @echo >&2 '***'
 693         @echo >&2 '*** Configuration file "$@" not found!'
 694         @echo >&2 '***'
 695         @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 696         @echo >&2 '*** "make menuconfig" or "make xconfig").'
 697         @echo >&2 '***'
 698         @/bin/false
 699
 700 # The actual configuration files used during the build are stored in
 701 # include/generated/ and include/config/. Update them if .config is newer than
 702 # include/config/auto.conf (which mirrors .config).
 703 #
 704 # This exploits the 'multi-target pattern rule' trick.
 705 # The syncconfig should be executed only once to make all the targets.
 706 # (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 707 quiet_cmd_syncconfig = SYNC    $@
 708       cmd_syncconfig = $(MAKE) -f $(srctree)/Makefile syncconfig
 709
 710 %/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 711         +$(call cmd,syncconfig)
 712 else # !may-sync-config
 713 # External modules and some install targets need include/generated/autoconf.h
 714 # and include/config/auto.conf but do not care if they are up-to-date.
 715 # Use auto.conf to trigger the test
 716 PHONY += include/config/auto.conf
 717
 718 include/config/auto.conf:
 719         $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 720         echo >&2;                                                       \
 721         echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 722         echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 723         echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 724         echo >&2 ;                                                      \
 725         /bin/false)
 726
 727 endif # may-sync-config
 728 endif # need-config
 729
 730 KBUILD_CFLAGS   += $(call cc-option,-fno-delete-null-pointer-checks,)
 731 KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 732 KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 733 KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 734 KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 735
 736 ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 737 KBUILD_CFLAGS += -O2
 738 else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
 739 KBUILD_CFLAGS += -O3
 740 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 741 KBUILD_CFLAGS += -Os
 742 endif
 743
 744 # Tell gcc to never replace conditional load with a non-conditional one
 745 KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 746 KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 747
 748 ifdef CONFIG_READABLE_ASM
 749 # Disable optimizations that make assembler listings hard to read.
 750 # reorder blocks reorders the control in the function
 751 # ipa clone creates specialized cloned functions
 752 # partial inlining inlines only parts of functions
 753 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
 754                  $(call cc-option,-fno-ipa-cp-clone,) \
 755                  $(call cc-option,-fno-partial-inlining)
 756 endif
 757
 758 ifneq ($(CONFIG_FRAME_WARN),0)
 759 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 760 endif
 761
 762 stackp-flags-y                                    := -fno-stack-protector
 763 stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 764 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 765
 766 KBUILD_CFLAGS += $(stackp-flags-y)
 767
 768 ifdef CONFIG_CC_IS_CLANG
 769 KBUILD_CPPFLAGS += -Qunused-arguments
 770 KBUILD_CFLAGS += -Wno-format-invalid-specifier
 771 KBUILD_CFLAGS += -Wno-gnu
 772 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 773 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 774 # See modpost pattern 2
 775 KBUILD_CFLAGS += -mno-global-merge
 776 else
 777
 778 # These warnings generated too much noise in a regular build.
 779 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 780 KBUILD_CFLAGS += -Wno-unused-but-set-variable
 781
 782 # Warn about unmarked fall-throughs in switch statement.
 783 # Disabled for clang while comment to attribute conversion happens and
 784 # https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
 785 KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
 786 endif
 787
 788 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 789 ifdef CONFIG_FRAME_POINTER
 790 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 791 else
 792 # Some targets (ARM with Thumb2, for example), can't be built with frame
 793 # pointers.  For those, we don't have FUNCTION_TRACER automatically
 794 # select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 795 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
 796 # -fomit-frame-pointer with FUNCTION_TRACER.
 797 ifndef CONFIG_FUNCTION_TRACER
 798 KBUILD_CFLAGS   += -fomit-frame-pointer
 799 endif
 800 endif
 801
 802 # Initialize all stack variables with a 0xAA pattern.
 803 ifdef CONFIG_INIT_STACK_ALL_PATTERN
 804 KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 805 endif
 806
 807 # Initialize all stack variables with a zero value.
 808 ifdef CONFIG_INIT_STACK_ALL_ZERO
 809 # Future support for zero initialization is still being debated, see
 810 # https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
 811 # renamed or dropped.
 812 KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 813 KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 814 endif
 815
 816 DEBUG_CFLAGS    :=
 817
 818 # Workaround for GCC versions < 5.0
 819 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
 820 ifdef CONFIG_CC_IS_GCC
 821 DEBUG_CFLAGS    += $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
 822 endif
 823
 824 ifdef CONFIG_DEBUG_INFO
 825
 826 ifdef CONFIG_DEBUG_INFO_SPLIT
 827 DEBUG_CFLAGS    += -gsplit-dwarf
 828 else
 829 DEBUG_CFLAGS    += -g
 830 endif
 831
 832 ifneq ($(LLVM_IAS),1)
 833 KBUILD_AFLAGS   += -Wa,-gdwarf-2
 834 endif
 835
 836 ifdef CONFIG_DEBUG_INFO_DWARF4
 837 DEBUG_CFLAGS    += -gdwarf-4
 838 endif
 839
 840 ifdef CONFIG_DEBUG_INFO_REDUCED
 841 DEBUG_CFLAGS    += $(call cc-option, -femit-struct-debug-baseonly) \
 842                    $(call cc-option,-fno-var-tracking)
 843 endif
 844
 845 ifdef CONFIG_DEBUG_INFO_COMPRESSED
 846 DEBUG_CFLAGS    += -gz=zlib
 847 KBUILD_AFLAGS   += -gz=zlib
 848 KBUILD_LDFLAGS  += --compress-debug-sections=zlib
 849 endif
 850
 851 endif # CONFIG_DEBUG_INFO
 852
 853 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 854 export DEBUG_CFLAGS
 855
 856 ifdef CONFIG_FUNCTION_TRACER
 857 ifdef CONFIG_FTRACE_MCOUNT_RECORD
 858   # gcc 5 supports generating the mcount tables directly
 859   ifeq ($(call cc-option-yn,-mrecord-mcount),y)
 860     CC_FLAGS_FTRACE     += -mrecord-mcount
 861     export CC_USING_RECORD_MCOUNT := 1
 862   endif
 863   ifdef CONFIG_HAVE_NOP_MCOUNT
 864     ifeq ($(call cc-option-yn, -mnop-mcount),y)
 865       CC_FLAGS_FTRACE   += -mnop-mcount
 866       CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 867     endif
 868   endif
 869 endif
 870 ifdef CONFIG_HAVE_FENTRY
 871   ifeq ($(call cc-option-yn, -mfentry),y)
 872     CC_FLAGS_FTRACE     += -mfentry
 873     CC_FLAGS_USING      += -DCC_USING_FENTRY
 874   endif
 875 endif
 876 export CC_FLAGS_FTRACE
 877 KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 878 KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 879 ifdef CONFIG_DYNAMIC_FTRACE
 880         ifdef CONFIG_HAVE_C_RECORDMCOUNT
 881                 BUILD_C_RECORDMCOUNT := y
 882                 export BUILD_C_RECORDMCOUNT
 883         endif
 884 endif
 885 endif
 886
 887 # We trigger additional mismatches with less inlining
 888 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 889 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 890 endif
 891
 892 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 893 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 894 LDFLAGS_vmlinux += --gc-sections
 895 endif
 896
 897 ifdef CONFIG_SHADOW_CALL_STACK
 898 CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 899 KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 900 export CC_FLAGS_SCS
 901 endif
 902
 903 ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_32B
 904 KBUILD_CFLAGS += -falign-functions=32
 905 endif
 906
 907 # arch Makefile may override CC so keep this after arch Makefile is included
 908 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 909
 910 # warn about C99 declaration after statement
 911 KBUILD_CFLAGS += -Wdeclaration-after-statement
 912
 913 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 914 KBUILD_CFLAGS += -Wvla
 915
 916 # disable pointer signed / unsigned warnings in gcc 4.0
 917 KBUILD_CFLAGS += -Wno-pointer-sign
 918
 919 # disable stringop warnings in gcc 8+
 920 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 921
 922 # We'll want to enable this eventually, but it's not going away for 5.7 at least
 923 KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
 924 KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
 925 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
 926
 927 # Another good warning that we'll want to enable eventually
 928 KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 929
 930 # Enabled with W=2, disabled by default as noisy
 931 KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
 932
 933 # disable invalid "can't wrap" optimizations for signed / pointers
 934 KBUILD_CFLAGS   += -fno-strict-overflow
 935
 936 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
 937 KBUILD_CFLAGS  += -fno-stack-check
 938
 939 # conserve stack if available
 940 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
 941
 942 # Prohibit date/time macros, which would make the build non-deterministic
 943 KBUILD_CFLAGS   += -Werror=date-time
 944
 945 # enforce correct pointer usage
 946 KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
 947
 948 # Require designated initializers for all marked structures
 949 KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
 950
 951 # change __FILE__ to the relative path from the srctree
 952 KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
 953
 954 # include additional Makefiles when needed
 955 include-y                       := scripts/Makefile.extrawarn
 956 include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
 957 include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
 958 include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
 959 include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
 960 include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
 961
 962 include $(addprefix $(srctree)/, $(include-y))
 963
 964 # scripts/Makefile.gcc-plugins is intentionally included last.
 965 # Do not add $(call cc-option,...) below this line. When you build the kernel
 966 # from the clean source tree, the GCC plugins do not exist at this point.
 967
 968 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 969 KBUILD_CPPFLAGS += $(KCPPFLAGS)
 970 KBUILD_AFLAGS   += $(KAFLAGS)
 971 KBUILD_CFLAGS   += $(KCFLAGS)
 972
 973 KBUILD_LDFLAGS_MODULE += --build-id=sha1
 974 LDFLAGS_vmlinux += --build-id=sha1
 975
 976 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
 977 LDFLAGS_vmlinux += $(call ld-option, -X,)
 978 endif
 979
 980 ifeq ($(CONFIG_RELR),y)
 981 LDFLAGS_vmlinux += --pack-dyn-relocs=relr
 982 endif
 983
 984 # We never want expected sections to be placed heuristically by the
 985 # linker. All sections should be explicitly named in the linker script.
 986 ifdef CONFIG_LD_ORPHAN_WARN
 987 LDFLAGS_vmlinux += --orphan-handling=warn
 988 endif
 989
 990 # Align the bit size of userspace programs with the kernel
 991 KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
 992 KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
 993
 994 # make the checker run with the right architecture
 995 CHECKFLAGS += --arch=$(ARCH)
 996
 997 # insure the checker run with the right endianness
 998 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
 999
1000 # the checker needs the correct machine size
1001 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1002
1003 # Default kernel image to build when no specific target is given.
1004 # KBUILD_IMAGE may be overruled on the command line or
1005 # set in the environment
1006 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
1007 # this default value
1008 export KBUILD_IMAGE ?= vmlinux
1009
1010 #
1011 # INSTALL_PATH specifies where to place the updated kernel and system map
1012 # images. Default is /boot, but you can set it to other values
1013 export  INSTALL_PATH ?= /boot
1014
1015 #
1016 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1017 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1018 # an argument if needed. Otherwise it defaults to the kernel install path
1019 #
1020 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1021
1022 #
1023 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1024 # relocations required by build roots.  This is not defined in the
1025 # makefile but the argument can be passed to make if needed.
1026 #
1027
1028 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1029 export MODLIB
1030
1031 #
1032 # INSTALL_MOD_STRIP, if defined, will cause modules to be
1033 # stripped after they are installed.  If INSTALL_MOD_STRIP is '1', then
1034 # the default option --strip-debug will be used.  Otherwise,
1035 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
1036
1037 ifdef INSTALL_MOD_STRIP
1038 ifeq ($(INSTALL_MOD_STRIP),1)
1039 mod_strip_cmd = $(STRIP) --strip-debug
1040 else
1041 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
1042 endif # INSTALL_MOD_STRIP=1
1043 else
1044 mod_strip_cmd = true
1045 endif # INSTALL_MOD_STRIP
1046 export mod_strip_cmd
1047
1048 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
1049 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
1050 # or CONFIG_MODULE_COMPRESS_XZ.
1051
1052 mod_compress_cmd = true
1053 ifdef CONFIG_MODULE_COMPRESS
1054   ifdef CONFIG_MODULE_COMPRESS_GZIP
1055     mod_compress_cmd = $(KGZIP) -n -f
1056   endif # CONFIG_MODULE_COMPRESS_GZIP
1057   ifdef CONFIG_MODULE_COMPRESS_XZ
1058     mod_compress_cmd = $(XZ) -f
1059   endif # CONFIG_MODULE_COMPRESS_XZ
1060 endif # CONFIG_MODULE_COMPRESS
1061 export mod_compress_cmd
1062
1063 ifdef CONFIG_MODULE_SIG_ALL
1064 $(eval $(call config_filename,MODULE_SIG_KEY))
1065
1066 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
1067 else
1068 mod_sign_cmd = true
1069 endif
1070 export mod_sign_cmd
1071
1072 HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
1073
1074 has_libelf = $(call try-run,\
1075                echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1076
1077 ifdef CONFIG_STACK_VALIDATION
1078   ifeq ($(has_libelf),1)
1079     objtool_target := tools/objtool FORCE
1080   else
1081     SKIP_STACK_VALIDATION := 1
1082     export SKIP_STACK_VALIDATION
1083   endif
1084 endif
1085
1086 PHONY += resolve_btfids_clean
1087
1088 resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1089
1090 # tools/bpf/resolve_btfids directory might not exist
1091 # in output directory, skip its clean in that case
1092 resolve_btfids_clean:
1093 ifneq ($(wildcard $(resolve_btfids_O)),)
1094         $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1095 endif
1096
1097 ifdef CONFIG_BPF
1098 ifdef CONFIG_DEBUG_INFO_BTF
1099   ifeq ($(has_libelf),1)
1100     resolve_btfids_target := tools/bpf/resolve_btfids FORCE
1101   else
1102     ERROR_RESOLVE_BTFIDS := 1
1103   endif
1104 endif # CONFIG_DEBUG_INFO_BTF
1105 endif # CONFIG_BPF
1106
1107 PHONY += prepare0
1108
1109 export MODORDER := $(extmod-prefix)modules.order
1110 export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps
1111
1112 ifeq ($(KBUILD_EXTMOD),)
1113 core-y          += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1114
1115 vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1116                      $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1117                      $(libs-y) $(libs-m)))
1118
1119 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1120                      $(patsubst %/,%,$(filter %/, $(core-) \
1121                         $(drivers-) $(libs-))))
1122
1123 subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1124                         $(core-y) $(core-m) $(libs-y) $(libs-m) \
1125                         $(drivers-y) $(drivers-m)))
1126
1127 build-dirs      := $(vmlinux-dirs)
1128 clean-dirs      := $(vmlinux-alldirs)
1129
1130 # Externally visible symbols (used by link-vmlinux.sh)
1131 KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1132 KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1133 ifdef CONFIG_MODULES
1134 KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1135 KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1136 else
1137 KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1138 endif
1139 KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1140
1141 export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1142 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1143 # used by scripts/Makefile.package
1144 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1145
1146 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1147
1148 # Recurse until adjust_autoksyms.sh is satisfied
1149 PHONY += autoksyms_recursive
1150 ifdef CONFIG_TRIM_UNUSED_KSYMS
1151 # For the kernel to actually contain only the needed exported symbols,
1152 # we have to build modules as well to determine what those symbols are.
1153 # (this can be evaluated only once include/config/auto.conf has been included)
1154 KBUILD_MODULES := 1
1155
1156 autoksyms_recursive: descend modules.order
1157         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1158           "$(MAKE) -f $(srctree)/Makefile vmlinux"
1159 endif
1160
1161 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1162
1163 quiet_cmd_autoksyms_h = GEN     $@
1164       cmd_autoksyms_h = mkdir -p $(dir $@); \
1165                         $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1166
1167 $(autoksyms_h):
1168         $(call cmd,autoksyms_h)
1169
1170 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1171
1172 # Final link of vmlinux with optional arch pass after final link
1173 cmd_link-vmlinux =                                                 \
1174         $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1175         $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1176
1177 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1178         +$(call if_changed,link-vmlinux)
1179
1180 targets := vmlinux
1181
1182 # The actual objects are generated when descending,
1183 # make sure no implicit rule kicks in
1184 $(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1185
1186 filechk_kernel.release = \
1187         echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1188
1189 # Store (new) KERNELRELEASE string in include/config/kernel.release
1190 include/config/kernel.release: FORCE
1191         $(call filechk,kernel.release)
1192
1193 # Additional helpers built in scripts/
1194 # Carefully list dependencies so we do not try to build scripts twice
1195 # in parallel
1196 PHONY += scripts
1197 scripts: scripts_basic scripts_dtc
1198         $(Q)$(MAKE) $(build)=$(@)
1199
1200 # Things we need to do before we recursively start building the kernel
1201 # or the modules are listed in "prepare".
1202 # A multi level approach is used. prepareN is processed before prepareN-1.
1203 # archprepare is used in arch Makefiles and when processed asm symlink,
1204 # version.h and scripts_basic is processed / created.
1205
1206 PHONY += prepare archprepare
1207
1208 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1209         asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1210         include/generated/autoconf.h
1211
1212 prepare0: archprepare
1213         $(Q)$(MAKE) $(build)=scripts/mod
1214         $(Q)$(MAKE) $(build)=.
1215
1216 # All the preparing..
1217 prepare: prepare0 prepare-objtool prepare-resolve_btfids
1218
1219 # Support for using generic headers in asm-generic
1220 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1221
1222 PHONY += asm-generic uapi-asm-generic
1223 asm-generic: uapi-asm-generic
1224         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1225         generic=include/asm-generic
1226 uapi-asm-generic:
1227         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1228         generic=include/uapi/asm-generic
1229
1230 PHONY += prepare-objtool prepare-resolve_btfids
1231 prepare-objtool: $(objtool_target)
1232 ifeq ($(SKIP_STACK_VALIDATION),1)
1233 ifdef CONFIG_UNWINDER_ORC
1234         @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1235         @false
1236 else
1237         @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1238 endif
1239 endif
1240
1241 prepare-resolve_btfids: $(resolve_btfids_target)
1242 ifeq ($(ERROR_RESOLVE_BTFIDS),1)
1243         @echo "error: Cannot resolve BTF IDs for CONFIG_DEBUG_INFO_BTF, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1244         @false
1245 endif
1246 # Generate some files
1247 # ---------------------------------------------------------------------------
1248
1249 # KERNELRELEASE can change from a few different places, meaning version.h
1250 # needs to be updated, so this check is forced on all builds
1251
1252 uts_len := 64
1253 define filechk_utsrelease.h
1254         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1255           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1256           exit 1;                                                         \
1257         fi;                                                               \
1258         echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1259 endef
1260
1261 define filechk_version.h
1262         if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1263                 echo \#define LINUX_VERSION_CODE $(shell                 \
1264                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1265         else                                                             \
1266                 echo \#define LINUX_VERSION_CODE $(shell                 \
1267                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1268         fi;                                                              \
1269         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1270         ((c) > 255 ? 255 : (c)))'
1271 endef
1272
1273 $(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1274 $(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1275 $(version_h): FORCE
1276         $(call filechk,version.h)
1277         $(Q)rm -f $(old_version_h)
1278
1279 include/generated/utsrelease.h: include/config/kernel.release FORCE
1280         $(call filechk,utsrelease.h)
1281
1282 PHONY += headerdep
1283 headerdep:
1284         $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1285         $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1286
1287 # ---------------------------------------------------------------------------
1288 # Kernel headers
1289
1290 #Default location for installed headers
1291 export INSTALL_HDR_PATH = $(objtree)/usr
1292
1293 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1294       cmd_headers_install = \
1295         mkdir -p $(INSTALL_HDR_PATH); \
1296         rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1297         usr/include $(INSTALL_HDR_PATH)
1298
1299 PHONY += headers_install
1300 headers_install: headers
1301         $(call cmd,headers_install)
1302
1303 PHONY += archheaders archscripts
1304
1305 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1306
1307 PHONY += headers
1308 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1309         $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1310           $(error Headers not exportable for the $(SRCARCH) architecture))
1311         $(Q)$(MAKE) $(hdr-inst)=include/uapi
1312         $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1313
1314 # Deprecated. It is no-op now.
1315 PHONY += headers_check
1316 headers_check:
1317         @:
1318
1319 ifdef CONFIG_HEADERS_INSTALL
1320 prepare: headers
1321 endif
1322
1323 PHONY += scripts_unifdef
1324 scripts_unifdef: scripts_basic
1325         $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1326
1327 # ---------------------------------------------------------------------------
1328 # Kernel selftest
1329
1330 PHONY += kselftest
1331 kselftest:
1332         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1333
1334 kselftest-%: FORCE
1335         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1336
1337 PHONY += kselftest-merge
1338 kselftest-merge:
1339         $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1340         $(Q)find $(srctree)/tools/testing/selftests -name config | \
1341                 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1342         $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1343
1344 # ---------------------------------------------------------------------------
1345 # Devicetree files
1346
1347 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1348 dtstree := arch/$(SRCARCH)/boot/dts
1349 endif
1350
1351 ifneq ($(dtstree),)
1352
1353 %.dtb: include/config/kernel.release scripts_dtc
1354         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1355
1356 PHONY += dtbs dtbs_install dtbs_check
1357 dtbs: include/config/kernel.release scripts_dtc
1358         $(Q)$(MAKE) $(build)=$(dtstree)
1359
1360 ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1361 export CHECK_DTBS=y
1362 dtbs: dt_binding_check
1363 endif
1364
1365 dtbs_check: dtbs
1366
1367 dtbs_install:
1368         $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1369
1370 ifdef CONFIG_OF_EARLY_FLATTREE
1371 all: dtbs
1372 endif
1373
1374 endif
1375
1376 PHONY += scripts_dtc
1377 scripts_dtc: scripts_basic
1378         $(Q)$(MAKE) $(build)=scripts/dtc
1379
1380 ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1381 export CHECK_DT_BINDING=y
1382 endif
1383
1384 PHONY += dt_binding_check
1385 dt_binding_check: scripts_dtc
1386         $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1387
1388 # ---------------------------------------------------------------------------
1389 # Modules
1390
1391 ifdef CONFIG_MODULES
1392
1393 # By default, build modules as well
1394
1395 all: modules
1396
1397 # When we're building modules with modversions, we need to consider
1398 # the built-in objects during the descend as well, in order to
1399 # make sure the checksums are up to date before we record them.
1400 ifdef CONFIG_MODVERSIONS
1401   KBUILD_BUILTIN := 1
1402 endif
1403
1404 # Build modules
1405 #
1406 # A module can be listed more than once in obj-m resulting in
1407 # duplicate lines in modules.order files.  Those are removed
1408 # using awk while concatenating to the final file.
1409
1410 PHONY += modules
1411 modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1412         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1413
1414 PHONY += modules_check
1415 modules_check: modules.order
1416         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1417
1418 cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1419
1420 modules.order: $(subdir-modorder) FORCE
1421         $(call if_changed,modules_order)
1422
1423 targets += modules.order
1424
1425 # Target to prepare building external modules
1426 PHONY += modules_prepare
1427 modules_prepare: prepare
1428         $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1429
1430 # Target to install modules
1431 PHONY += modules_install
1432 modules_install: _modinst_ _modinst_post
1433
1434 PHONY += _modinst_
1435 _modinst_:
1436         @rm -rf $(MODLIB)/kernel
1437         @rm -f $(MODLIB)/source
1438         @mkdir -p $(MODLIB)/kernel
1439         @ln -s $(abspath $(srctree)) $(MODLIB)/source
1440         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1441                 rm -f $(MODLIB)/build ; \
1442                 ln -s $(CURDIR) $(MODLIB)/build ; \
1443         fi
1444         @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1445         @cp -f modules.builtin $(MODLIB)/
1446         @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1447         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1448
1449 # This depmod is only for convenience to give the initial
1450 # boot a modules.dep even before / is mounted read-write.  However the
1451 # boot script depmod is the master version.
1452 PHONY += _modinst_post
1453 _modinst_post: _modinst_
1454         $(call cmd,depmod)
1455
1456 ifeq ($(CONFIG_MODULE_SIG), y)
1457 PHONY += modules_sign
1458 modules_sign:
1459         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1460 endif
1461
1462 else # CONFIG_MODULES
1463
1464 # Modules not configured
1465 # ---------------------------------------------------------------------------
1466
1467 PHONY += modules modules_install
1468 modules modules_install:
1469         @echo >&2
1470         @echo >&2 "The present kernel configuration has modules disabled."
1471         @echo >&2 "Type 'make config' and enable loadable module support."
1472         @echo >&2 "Then build a kernel with module support enabled."
1473         @echo >&2
1474         @exit 1
1475
1476 endif # CONFIG_MODULES
1477
1478 ###
1479 # Cleaning is done on three levels.
1480 # make clean     Delete most generated files
1481 #                Leave enough to build external modules
1482 # make mrproper  Delete the current configuration, and all generated files
1483 # make distclean Remove editor backup files, patch leftover files and the like
1484
1485 # Directories & files removed with 'make clean'
1486 CLEAN_FILES += include/ksym vmlinux.symvers \
1487                modules.builtin modules.builtin.modinfo modules.nsdeps \
1488                compile_commands.json
1489
1490 # Directories & files removed with 'make mrproper'
1491 MRPROPER_FILES += include/config include/generated          \
1492                   arch/$(SRCARCH)/include/generated .tmp_objdiff \
1493                   debian snap tar-install \
1494                   .config .config.old .version \
1495                   Module.symvers \
1496                   signing_key.pem signing_key.priv signing_key.x509     \
1497                   x509.genkey extra_certificates signing_key.x509.keyid \
1498                   signing_key.x509.signer vmlinux-gdb.py \
1499                   *.spec
1500
1501 # Directories & files removed with 'make distclean'
1502 DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1503
1504 # clean - Delete most, but leave enough to build external modules
1505 #
1506 clean: rm-files := $(CLEAN_FILES)
1507
1508 PHONY += archclean vmlinuxclean
1509
1510 vmlinuxclean:
1511         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1512         $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1513
1514 clean: archclean vmlinuxclean resolve_btfids_clean
1515
1516 # mrproper - Delete all generated files, including .config
1517 #
1518 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1519 mrproper-dirs      := $(addprefix _mrproper_,scripts)
1520
1521 PHONY += $(mrproper-dirs) mrproper
1522 $(mrproper-dirs):
1523         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1524
1525 mrproper: clean $(mrproper-dirs)
1526         $(call cmd,rmfiles)
1527
1528 # distclean
1529 #
1530 distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1531
1532 PHONY += distclean
1533
1534 distclean: mrproper
1535         $(call cmd,rmfiles)
1536         @find $(srctree) $(RCS_FIND_IGNORE) \
1537                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1538                 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1539                 -o -name 'core' \) \
1540                 -type f -print | xargs rm -f
1541
1542
1543 # Packaging of the kernel to various formats
1544 # ---------------------------------------------------------------------------
1545
1546 %src-pkg: FORCE
1547         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1548 %pkg: include/config/kernel.release FORCE
1549         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1550
1551 # Brief documentation of the typical targets used
1552 # ---------------------------------------------------------------------------
1553
1554 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1555 boards := $(sort $(notdir $(boards)))
1556 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1557 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1558
1559 PHONY += help
1560 help:
1561         @echo  'Cleaning targets:'
1562         @echo  '  clean           - Remove most generated files but keep the config and'
1563         @echo  '                    enough build support to build external modules'
1564         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1565         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1566         @echo  ''
1567         @echo  'Configuration targets:'
1568         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1569         @echo  ''
1570         @echo  'Other generic targets:'
1571         @echo  '  all             - Build all targets marked with [*]'
1572         @echo  '* vmlinux         - Build the bare kernel'
1573         @echo  '* modules         - Build all modules'
1574         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1575         @echo  '  dir/            - Build all files in dir and below'
1576         @echo  '  dir/file.[ois]  - Build specified target only'
1577         @echo  '  dir/file.ll     - Build the LLVM assembly file'
1578         @echo  '                    (requires compiler support for LLVM assembly generation)'
1579         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1580         @echo  '                    (requires a recent binutils and recent build (System.map))'
1581         @echo  '  dir/file.ko     - Build module including final link'
1582         @echo  '  modules_prepare - Set up for building external modules'
1583         @echo  '  tags/TAGS       - Generate tags file for editors'
1584         @echo  '  cscope          - Generate cscope index'
1585         @echo  '  gtags           - Generate GNU GLOBAL index'
1586         @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1587         @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1588         @echo  '  image_name      - Output the image name (use with make -s)'
1589         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1590          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1591          echo  ''
1592         @echo  'Static analysers:'
1593         @echo  '  checkstack      - Generate a list of stack hogs'
1594         @echo  '  versioncheck    - Sanity check on version.h usage'
1595         @echo  '  includecheck    - Check for duplicate included header files'
1596         @echo  '  export_report   - List the usages of all exported symbols'
1597         @echo  '  headerdep       - Detect inclusion cycles in headers'
1598         @echo  '  coccicheck      - Check with Coccinelle'
1599         @echo  '  clang-analyzer  - Check with clang static analyzer'
1600         @echo  '  clang-tidy      - Check with clang-tidy'
1601         @echo  ''
1602         @echo  'Tools:'
1603         @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1604         @echo  ''
1605         @echo  'Kernel selftest:'
1606         @echo  '  kselftest         - Build and run kernel selftest'
1607         @echo  '                      Build, install, and boot kernel before'
1608         @echo  '                      running kselftest on it'
1609         @echo  '                      Run as root for full coverage'
1610         @echo  '  kselftest-all     - Build kernel selftest'
1611         @echo  '  kselftest-install - Build and install kernel selftest'
1612         @echo  '  kselftest-clean   - Remove all generated kselftest files'
1613         @echo  '  kselftest-merge   - Merge all the config dependencies of'
1614         @echo  '                      kselftest to existing .config.'
1615         @echo  ''
1616         @$(if $(dtstree), \
1617                 echo 'Devicetree:'; \
1618                 echo '* dtbs             - Build device tree blobs for enabled boards'; \
1619                 echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1620                 echo '  dt_binding_check - Validate device tree binding documents'; \
1621                 echo '  dtbs_check       - Validate device tree source files';\
1622                 echo '')
1623
1624         @echo 'Userspace tools targets:'
1625         @echo '  use "make tools/help"'
1626         @echo '  or  "cd tools; make help"'
1627         @echo  ''
1628         @echo  'Kernel packaging:'
1629         @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1630         @echo  ''
1631         @echo  'Documentation targets:'
1632         @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1633         @echo  ''
1634         @echo  'Architecture specific targets ($(SRCARCH)):'
1635         @$(if $(archhelp),$(archhelp),\
1636                 echo '  No architecture specific help defined for $(SRCARCH)')
1637         @echo  ''
1638         @$(if $(boards), \
1639                 $(foreach b, $(boards), \
1640                 printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1641                 echo '')
1642         @$(if $(board-dirs), \
1643                 $(foreach b, $(board-dirs), \
1644                 printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1645                 printf "  %-16s - Show all of the above\\n" help-boards; \
1646                 echo '')
1647
1648         @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1649         @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1650         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1651         @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1652         @echo  '                       (sparse by default)'
1653         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1654         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1655         @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1656         @echo  '                1: warnings which may be relevant and do not occur too often'
1657         @echo  '                2: warnings which occur quite often but may still be relevant'
1658         @echo  '                3: more obscure warnings, can most likely be ignored'
1659         @echo  '                Multiple levels can be combined with W=12 or W=123'
1660         @echo  ''
1661         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1662         @echo  'For further info see the ./README file'
1663
1664
1665 help-board-dirs := $(addprefix help-,$(board-dirs))
1666
1667 help-boards: $(help-board-dirs)
1668
1669 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1670
1671 $(help-board-dirs): help-%:
1672         @echo  'Architecture specific targets ($(SRCARCH) $*):'
1673         @$(if $(boards-per-dir), \
1674                 $(foreach b, $(boards-per-dir), \
1675                 printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1676                 echo '')
1677
1678
1679 # Documentation targets
1680 # ---------------------------------------------------------------------------
1681 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1682                linkcheckdocs dochelp refcheckdocs
1683 PHONY += $(DOC_TARGETS)
1684 $(DOC_TARGETS):
1685         $(Q)$(MAKE) $(build)=Documentation $@
1686
1687 # Misc
1688 # ---------------------------------------------------------------------------
1689
1690 PHONY += scripts_gdb
1691 scripts_gdb: prepare0
1692         $(Q)$(MAKE) $(build)=scripts/gdb
1693         $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1694
1695 ifdef CONFIG_GDB_SCRIPTS
1696 all: scripts_gdb
1697 endif
1698
1699 else # KBUILD_EXTMOD
1700
1701 ###
1702 # External module support.
1703 # When building external modules the kernel used as basis is considered
1704 # read-only, and no consistency checks are made and the make
1705 # system is not used on the basis kernel. If updates are required
1706 # in the basis kernel ordinary make commands (without M=...) must
1707 # be used.
1708 #
1709 # The following are the only valid targets when building external
1710 # modules.
1711 # make M=dir clean     Delete all automatically generated files
1712 # make M=dir modules   Make all modules in specified dir
1713 # make M=dir           Same as 'make M=dir modules'
1714 # make M=dir modules_install
1715 #                      Install the modules built in the module directory
1716 #                      Assumes install directory is already created
1717
1718 # We are always building only modules.
1719 KBUILD_BUILTIN :=
1720 KBUILD_MODULES := 1
1721
1722 build-dirs := $(KBUILD_EXTMOD)
1723 PHONY += modules
1724 modules: $(MODORDER)
1725         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1726
1727 $(MODORDER): descend
1728         @:
1729
1730 PHONY += modules_install
1731 modules_install: _emodinst_ _emodinst_post
1732
1733 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1734 PHONY += _emodinst_
1735 _emodinst_:
1736         $(Q)mkdir -p $(MODLIB)/$(install-dir)
1737         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1738
1739 PHONY += _emodinst_post
1740 _emodinst_post: _emodinst_
1741         $(call cmd,depmod)
1742
1743 compile_commands.json: $(extmod-prefix)compile_commands.json
1744 PHONY += compile_commands.json
1745
1746 clean-dirs := $(KBUILD_EXTMOD)
1747 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1748         $(KBUILD_EXTMOD)/compile_commands.json
1749
1750 PHONY += help
1751 help:
1752         @echo  '  Building external modules.'
1753         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1754         @echo  ''
1755         @echo  '  modules         - default target, build the module(s)'
1756         @echo  '  modules_install - install the module'
1757         @echo  '  clean           - remove generated files in module directory only'
1758         @echo  ''
1759
1760 # no-op for external module builds
1761 PHONY += prepare modules_prepare
1762
1763 endif # KBUILD_EXTMOD
1764
1765 # Single targets
1766 # ---------------------------------------------------------------------------
1767 # To build individual files in subdirectories, you can do like this:
1768 #
1769 #   make foo/bar/baz.s
1770 #
1771 # The supported suffixes for single-target are listed in 'single-targets'
1772 #
1773 # To build only under specific subdirectories, you can do like this:
1774 #
1775 #   make foo/bar/baz/
1776
1777 ifdef single-build
1778
1779 # .ko is special because modpost is needed
1780 single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1781 single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1782
1783 $(single-ko): single_modpost
1784         @:
1785 $(single-no-ko): descend
1786         @:
1787
1788 ifeq ($(KBUILD_EXTMOD),)
1789 # For the single build of in-tree modules, use a temporary file to avoid
1790 # the situation of modules_install installing an invalid modules.order.
1791 MODORDER := .modules.tmp
1792 endif
1793
1794 PHONY += single_modpost
1795 single_modpost: $(single-no-ko) modules_prepare
1796         $(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
1797         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1798
1799 KBUILD_MODULES := 1
1800
1801 export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
1802
1803 # trim unrelated directories
1804 build-dirs := $(foreach d, $(build-dirs), \
1805                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1806
1807 endif
1808
1809 ifndef CONFIG_MODULES
1810 KBUILD_MODULES :=
1811 endif
1812
1813 # Handle descending into subdirectories listed in $(build-dirs)
1814 # Preset locale variables to speed up the build process. Limit locale
1815 # tweaks to this spot to avoid wrong language settings when running
1816 # make menuconfig etc.
1817 # Error messages still appears in the original language
1818 PHONY += descend $(build-dirs)
1819 descend: $(build-dirs)
1820 $(build-dirs): prepare
1821         $(Q)$(MAKE) $(build)=$@ \
1822         single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1823         need-builtin=1 need-modorder=1
1824
1825 clean-dirs := $(addprefix _clean_, $(clean-dirs))
1826 PHONY += $(clean-dirs) clean
1827 $(clean-dirs):
1828         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1829
1830 clean: $(clean-dirs)
1831         $(call cmd,rmfiles)
1832         @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1833                 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1834                 -o -name '*.ko.*' \
1835                 -o -name '*.dtb' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1836                 -o -name '*.dwo' -o -name '*.lst' \
1837                 -o -name '*.su' -o -name '*.mod' \
1838                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1839                 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1840                 -o -name '*.asn1.[ch]' \
1841                 -o -name '*.symtypes' -o -name 'modules.order' \
1842                 -o -name '.tmp_*.o.*' \
1843                 -o -name '*.c.[012]*.*' \
1844                 -o -name '*.ll' \
1845                 -o -name '*.gcno' \) -type f -print | xargs rm -f
1846
1847 # Generate tags for editors
1848 # ---------------------------------------------------------------------------
1849 quiet_cmd_tags = GEN     $@
1850       cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1851
1852 tags TAGS cscope gtags: FORCE
1853         $(call cmd,tags)
1854
1855 # Script to generate missing namespace dependencies
1856 # ---------------------------------------------------------------------------
1857
1858 PHONY += nsdeps
1859 nsdeps: export KBUILD_NSDEPS=1
1860 nsdeps: modules
1861         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1862
1863 # Clang Tooling
1864 # ---------------------------------------------------------------------------
1865
1866 quiet_cmd_gen_compile_commands = GEN     $@
1867       cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1868
1869 $(extmod-prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1870         $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1871         $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1872         $(call if_changed,gen_compile_commands)
1873
1874 targets += $(extmod-prefix)compile_commands.json
1875
1876 PHONY += clang-tidy clang-analyzer
1877
1878 ifdef CONFIG_CC_IS_CLANG
1879 quiet_cmd_clang_tools = CHECK   $<
1880       cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1881
1882 clang-tidy clang-analyzer: $(extmod-prefix)compile_commands.json
1883         $(call cmd,clang_tools)
1884 else
1885 clang-tidy clang-analyzer:
1886         @echo "$@ requires CC=clang" >&2
1887         @false
1888 endif
1889
1890 # Scripts to check various things for consistency
1891 # ---------------------------------------------------------------------------
1892
1893 PHONY += includecheck versioncheck coccicheck export_report
1894
1895 includecheck:
1896         find $(srctree)/* $(RCS_FIND_IGNORE) \
1897                 -name '*.[hcS]' -type f -print | sort \
1898                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1899
1900 versioncheck:
1901         find $(srctree)/* $(RCS_FIND_IGNORE) \
1902                 -name '*.[hcS]' -type f -print | sort \
1903                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1904
1905 coccicheck:
1906         $(Q)$(BASH) $(srctree)/scripts/$@
1907
1908 export_report:
1909         $(PERL) $(srctree)/scripts/export_report.pl
1910
1911 PHONY += checkstack kernelrelease kernelversion image_name
1912
1913 # UML needs a little special treatment here.  It wants to use the host
1914 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1915 # else wants $(ARCH), including people doing cross-builds, which means
1916 # that $(SUBARCH) doesn't work here.
1917 ifeq ($(ARCH), um)
1918 CHECKSTACK_ARCH := $(SUBARCH)
1919 else
1920 CHECKSTACK_ARCH := $(ARCH)
1921 endif
1922 checkstack:
1923         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1924         $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1925
1926 kernelrelease:
1927         @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1928
1929 kernelversion:
1930         @echo $(KERNELVERSION)
1931
1932 image_name:
1933         @echo $(KBUILD_IMAGE)
1934
1935 # Clear a bunch of variables before executing the submake
1936
1937 ifeq ($(quiet),silent_)
1938 tools_silent=s
1939 endif
1940
1941 tools/: FORCE
1942         $(Q)mkdir -p $(objtree)/tools
1943         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1944
1945 tools/%: FORCE
1946         $(Q)mkdir -p $(objtree)/tools
1947         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1948
1949 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1950       cmd_rmfiles = rm -rf $(rm-files)
1951
1952 # Run depmod only if we have System.map and depmod is executable
1953 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
1954       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1955                    $(KERNELRELEASE)
1956
1957 # read saved command lines for existing targets
1958 existing-targets := $(wildcard $(sort $(targets)))
1959
1960 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1961
1962 endif # config-build
1963 endif # mixed-build
1964 endif # need-sub-make
1965
1966 PHONY += FORCE
1967 FORCE:
1968
1969 # Declare the contents of the PHONY variable as phony.  We keep that
1970 # information in a variable so we can use it in if_changed and friends.
1971 .PHONY: $(PHONY)