Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 VERSION = 5
   3 PATCHLEVEL = 11
   4 SUBLEVEL = 0
   5 EXTRAVERSION =
   6 NAME = 💕 Valentine's Day Edition 💕
   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 := $(no-dot-config-targets) %install kernelrelease
 269 single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
 270
 271 config-build    :=
 272 mixed-build     :=
 273 need-config     := 1
 274 may-sync-config := 1
 275 single-build    :=
 276
 277 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 278         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 279                 need-config :=
 280         endif
 281 endif
 282
 283 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 284         ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 285                 may-sync-config :=
 286         endif
 287 endif
 288
 289 ifneq ($(KBUILD_EXTMOD),)
 290         may-sync-config :=
 291 endif
 292
 293 ifeq ($(KBUILD_EXTMOD),)
 294         ifneq ($(filter %config,$(MAKECMDGOALS)),)
 295                 config-build := 1
 296                 ifneq ($(words $(MAKECMDGOALS)),1)
 297                         mixed-build := 1
 298                 endif
 299         endif
 300 endif
 301
 302 # We cannot build single targets and the others at the same time
 303 ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 304         single-build := 1
 305         ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 306                 mixed-build := 1
 307         endif
 308 endif
 309
 310 # For "make -j clean all", "make -j mrproper defconfig all", etc.
 311 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 312         ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 313                 mixed-build := 1
 314         endif
 315 endif
 316
 317 # install and modules_install need also be processed one by one
 318 ifneq ($(filter install,$(MAKECMDGOALS)),)
 319         ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 320                 mixed-build := 1
 321         endif
 322 endif
 323
 324 ifdef mixed-build
 325 # ===========================================================================
 326 # We're called with mixed targets (*config and build targets).
 327 # Handle them one by one.
 328
 329 PHONY += $(MAKECMDGOALS) __build_one_by_one
 330
 331 $(MAKECMDGOALS): __build_one_by_one
 332         @:
 333
 334 __build_one_by_one:
 335         $(Q)set -e; \
 336         for i in $(MAKECMDGOALS); do \
 337                 $(MAKE) -f $(srctree)/Makefile $$i; \
 338         done
 339
 340 else # !mixed-build
 341
 342 include scripts/Kbuild.include
 343
 344 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 345 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 346 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 347 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 348
 349 include scripts/subarch.include
 350
 351 # Cross compiling and selecting different set of gcc/bin-utils
 352 # ---------------------------------------------------------------------------
 353 #
 354 # When performing cross compilation for other architectures ARCH shall be set
 355 # to the target architecture. (See arch/* for the possibilities).
 356 # ARCH can be set during invocation of make:
 357 # make ARCH=ia64
 358 # Another way is to have ARCH set in the environment.
 359 # The default ARCH is the host where make is executed.
 360
 361 # CROSS_COMPILE specify the prefix used for all executables used
 362 # during compilation. Only gcc and related bin-utils executables
 363 # are prefixed with $(CROSS_COMPILE).
 364 # CROSS_COMPILE can be set on the command line
 365 # make CROSS_COMPILE=ia64-linux-
 366 # Alternatively CROSS_COMPILE can be set in the environment.
 367 # Default value for CROSS_COMPILE is not to prefix executables
 368 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 369 ARCH            ?= $(SUBARCH)
 370
 371 # Architecture as present in compile.h
 372 UTS_MACHINE     := $(ARCH)
 373 SRCARCH         := $(ARCH)
 374
 375 # Additional ARCH settings for x86
 376 ifeq ($(ARCH),i386)
 377         SRCARCH := x86
 378 endif
 379 ifeq ($(ARCH),x86_64)
 380         SRCARCH := x86
 381 endif
 382
 383 # Additional ARCH settings for sparc
 384 ifeq ($(ARCH),sparc32)
 385        SRCARCH := sparc
 386 endif
 387 ifeq ($(ARCH),sparc64)
 388        SRCARCH := sparc
 389 endif
 390
 391 # Additional ARCH settings for sh
 392 ifeq ($(ARCH),sh64)
 393        SRCARCH := sh
 394 endif
 395
 396 KCONFIG_CONFIG  ?= .config
 397 export KCONFIG_CONFIG
 398
 399 # Default file for 'make defconfig'. This may be overridden by arch-Makefile.
 400 export KBUILD_DEFCONFIG := defconfig
 401
 402 # SHELL used by kbuild
 403 CONFIG_SHELL := sh
 404
 405 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 406 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 407 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 408
 409 ifneq ($(LLVM),)
 410 HOSTCC  = clang
 411 HOSTCXX = clang++
 412 else
 413 HOSTCC  = gcc
 414 HOSTCXX = g++
 415 endif
 416
 417 export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 418                               -O2 -fomit-frame-pointer -std=gnu89
 419 export KBUILD_USERLDFLAGS :=
 420
 421 KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 422 KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 423 KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 424 KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 425
 426 # Make variables (CC, etc...)
 427 CPP             = $(CC) -E
 428 ifneq ($(LLVM),)
 429 CC              = clang
 430 LD              = ld.lld
 431 AR              = llvm-ar
 432 NM              = llvm-nm
 433 OBJCOPY         = llvm-objcopy
 434 OBJDUMP         = llvm-objdump
 435 READELF         = llvm-readelf
 436 STRIP           = llvm-strip
 437 else
 438 CC              = $(CROSS_COMPILE)gcc
 439 LD              = $(CROSS_COMPILE)ld
 440 AR              = $(CROSS_COMPILE)ar
 441 NM              = $(CROSS_COMPILE)nm
 442 OBJCOPY         = $(CROSS_COMPILE)objcopy
 443 OBJDUMP         = $(CROSS_COMPILE)objdump
 444 READELF         = $(CROSS_COMPILE)readelf
 445 STRIP           = $(CROSS_COMPILE)strip
 446 endif
 447 PAHOLE          = pahole
 448 RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 449 LEX             = flex
 450 YACC            = bison
 451 AWK             = awk
 452 INSTALLKERNEL  := installkernel
 453 DEPMOD          = depmod
 454 PERL            = perl
 455 PYTHON3         = python3
 456 CHECK           = sparse
 457 BASH            = bash
 458 KGZIP           = gzip
 459 KBZIP2          = bzip2
 460 KLZOP           = lzop
 461 LZMA            = lzma
 462 LZ4             = lz4c
 463 XZ              = xz
 464 ZSTD            = zstd
 465
 466 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 467                   -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 468 NOSTDINC_FLAGS :=
 469 CFLAGS_MODULE   =
 470 AFLAGS_MODULE   =
 471 LDFLAGS_MODULE  =
 472 CFLAGS_KERNEL   =
 473 AFLAGS_KERNEL   =
 474 LDFLAGS_vmlinux =
 475
 476 # Use USERINCLUDE when you must reference the UAPI directories only.
 477 USERINCLUDE    := \
 478                 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 479                 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 480                 -I$(srctree)/include/uapi \
 481                 -I$(objtree)/include/generated/uapi \
 482                 -include $(srctree)/include/linux/kconfig.h
 483
 484 # Use LINUXINCLUDE when you must reference the include/ directory.
 485 # Needed to be compatible with the O= option
 486 LINUXINCLUDE    := \
 487                 -I$(srctree)/arch/$(SRCARCH)/include \
 488                 -I$(objtree)/arch/$(SRCARCH)/include/generated \
 489                 $(if $(building_out_of_srctree),-I$(srctree)/include) \
 490                 -I$(objtree)/include \
 491                 $(USERINCLUDE)
 492
 493 KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 494 KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 495                    -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 496                    -Werror=implicit-function-declaration -Werror=implicit-int \
 497                    -Werror=return-type -Wno-format-security \
 498                    -std=gnu89
 499 KBUILD_CPPFLAGS := -D__KERNEL__
 500 KBUILD_AFLAGS_KERNEL :=
 501 KBUILD_CFLAGS_KERNEL :=
 502 KBUILD_AFLAGS_MODULE  := -DMODULE
 503 KBUILD_CFLAGS_MODULE  := -DMODULE
 504 KBUILD_LDFLAGS_MODULE :=
 505 KBUILD_LDFLAGS :=
 506 CLANG_FLAGS :=
 507
 508 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
 509 export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 510 export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 511 export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 512 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 513
 514 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 515 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 516 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 517 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 518 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 519
 520 # Files to ignore in find ... statements
 521
 522 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 523                           -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 524                           -prune -o
 525 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 526                          --exclude CVS --exclude .pc --exclude .hg --exclude .git
 527
 528 # ===========================================================================
 529 # Rules shared between *config targets and build targets
 530
 531 # Basic helpers built in scripts/basic/
 532 PHONY += scripts_basic
 533 scripts_basic:
 534         $(Q)$(MAKE) $(build)=scripts/basic
 535         $(Q)rm -f .tmp_quiet_recordmcount
 536
 537 PHONY += outputmakefile
 538 # Before starting out-of-tree build, make sure the source tree is clean.
 539 # outputmakefile generates a Makefile in the output directory, if using a
 540 # separate output directory. This allows convenient use of make in the
 541 # output directory.
 542 # At the same time when output Makefile generated, generate .gitignore to
 543 # ignore whole output directory
 544 outputmakefile:
 545 ifdef building_out_of_srctree
 546         $(Q)if [ -f $(srctree)/.config -o \
 547                  -d $(srctree)/include/config -o \
 548                  -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 549                 echo >&2 "***"; \
 550                 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 551                 echo >&2 "*** in $(abs_srctree)";\
 552                 echo >&2 "***"; \
 553                 false; \
 554         fi
 555         $(Q)ln -fsn $(srctree) source
 556         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
 557         $(Q)test -e .gitignore || \
 558         { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 559 endif
 560
 561 ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),)
 562 ifneq ($(CROSS_COMPILE),)
 563 CLANG_FLAGS     += --target=$(notdir $(CROSS_COMPILE:%-=%))
 564 GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
 565 CLANG_FLAGS     += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
 566 GCC_TOOLCHAIN   := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
 567 endif
 568 ifneq ($(GCC_TOOLCHAIN),)
 569 CLANG_FLAGS     += --gcc-toolchain=$(GCC_TOOLCHAIN)
 570 endif
 571 ifneq ($(LLVM_IAS),1)
 572 CLANG_FLAGS     += -no-integrated-as
 573 endif
 574 CLANG_FLAGS     += -Werror=unknown-warning-option
 575 KBUILD_CFLAGS   += $(CLANG_FLAGS)
 576 KBUILD_AFLAGS   += $(CLANG_FLAGS)
 577 export CLANG_FLAGS
 578 endif
 579
 580 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 581 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 582 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 583 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
 584 CC_VERSION_TEXT = $(shell $(CC) --version 2>/dev/null | head -n 1)
 585
 586 ifdef config-build
 587 # ===========================================================================
 588 # *config targets only - make sure prerequisites are updated, and descend
 589 # in scripts/kconfig to make the *config target
 590
 591 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 592 # KBUILD_DEFCONFIG may point out an alternative default configuration
 593 # used for 'make defconfig'
 594 include arch/$(SRCARCH)/Makefile
 595 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 596
 597 config: outputmakefile scripts_basic FORCE
 598         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 599
 600 %config: outputmakefile scripts_basic FORCE
 601         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 602
 603 else #!config-build
 604 # ===========================================================================
 605 # Build targets only - this includes vmlinux, arch specific targets, clean
 606 # targets and others. In general all targets except *config targets.
 607
 608 # If building an external module we do not care about the all: rule
 609 # but instead __all depend on modules
 610 PHONY += all
 611 ifeq ($(KBUILD_EXTMOD),)
 612 __all: all
 613 else
 614 __all: modules
 615 endif
 616
 617 # Decide whether to build built-in, modular, or both.
 618 # Normally, just do built-in.
 619
 620 KBUILD_MODULES :=
 621 KBUILD_BUILTIN := 1
 622
 623 # If we have only "make modules", don't compile built-in objects.
 624 ifeq ($(MAKECMDGOALS),modules)
 625   KBUILD_BUILTIN :=
 626 endif
 627
 628 # If we have "make <whatever> modules", compile modules
 629 # in addition to whatever we do anyway.
 630 # Just "make" or "make all" shall build modules as well
 631
 632 ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 633   KBUILD_MODULES := 1
 634 endif
 635
 636 ifeq ($(MAKECMDGOALS),)
 637   KBUILD_MODULES := 1
 638 endif
 639
 640 export KBUILD_MODULES KBUILD_BUILTIN
 641
 642 ifdef need-config
 643 include include/config/auto.conf
 644 endif
 645
 646 ifeq ($(KBUILD_EXTMOD),)
 647 # Objects we will link into vmlinux / subdirs we need to visit
 648 core-y          := init/ usr/
 649 drivers-y       := drivers/ sound/
 650 drivers-$(CONFIG_SAMPLES) += samples/
 651 drivers-$(CONFIG_NET) += net/
 652 drivers-y       += virt/
 653 libs-y          := lib/
 654 endif # KBUILD_EXTMOD
 655
 656 # The all: target is the default when no target is given on the
 657 # command line.
 658 # This allow a user to issue only 'make' to build a kernel including modules
 659 # Defaults to vmlinux, but the arch makefile usually adds further targets
 660 all: vmlinux
 661
 662 CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage \
 663         $(call cc-option,-fno-tree-loop-im) \
 664         $(call cc-disable-warning,maybe-uninitialized,)
 665 export CFLAGS_GCOV
 666
 667 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 668 ifdef CONFIG_FUNCTION_TRACER
 669   CC_FLAGS_FTRACE := -pg
 670 endif
 671
 672 RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
 673 RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
 674 RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
 675 RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
 676 RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
 677 RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
 678 export RETPOLINE_CFLAGS
 679 export RETPOLINE_VDSO_CFLAGS
 680
 681 include arch/$(SRCARCH)/Makefile
 682
 683 ifdef need-config
 684 ifdef may-sync-config
 685 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 686 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 687 # because some architectures define CROSS_COMPILE there.
 688 include include/config/auto.conf.cmd
 689
 690 $(KCONFIG_CONFIG):
 691         @echo >&2 '***'
 692         @echo >&2 '*** Configuration file "$@" not found!'
 693         @echo >&2 '***'
 694         @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 695         @echo >&2 '*** "make menuconfig" or "make xconfig").'
 696         @echo >&2 '***'
 697         @/bin/false
 698
 699 # The actual configuration files used during the build are stored in
 700 # include/generated/ and include/config/. Update them if .config is newer than
 701 # include/config/auto.conf (which mirrors .config).
 702 #
 703 # This exploits the 'multi-target pattern rule' trick.
 704 # The syncconfig should be executed only once to make all the targets.
 705 # (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 706 quiet_cmd_syncconfig = SYNC    $@
 707       cmd_syncconfig = $(MAKE) -f $(srctree)/Makefile syncconfig
 708
 709 %/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 710         +$(call cmd,syncconfig)
 711 else # !may-sync-config
 712 # External modules and some install targets need include/generated/autoconf.h
 713 # and include/config/auto.conf but do not care if they are up-to-date.
 714 # Use auto.conf to trigger the test
 715 PHONY += include/config/auto.conf
 716
 717 include/config/auto.conf:
 718         $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 719         echo >&2;                                                       \
 720         echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 721         echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 722         echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 723         echo >&2 ;                                                      \
 724         /bin/false)
 725
 726 endif # may-sync-config
 727 endif # need-config
 728
 729 KBUILD_CFLAGS   += $(call cc-option,-fno-delete-null-pointer-checks,)
 730 KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 731 KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 732 KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 733 KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 734
 735 ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 736 KBUILD_CFLAGS += -O2
 737 else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
 738 KBUILD_CFLAGS += -O3
 739 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 740 KBUILD_CFLAGS += -Os
 741 endif
 742
 743 # Tell gcc to never replace conditional load with a non-conditional one
 744 KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 745 KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 746
 747 ifdef CONFIG_READABLE_ASM
 748 # Disable optimizations that make assembler listings hard to read.
 749 # reorder blocks reorders the control in the function
 750 # ipa clone creates specialized cloned functions
 751 # partial inlining inlines only parts of functions
 752 KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
 753                  $(call cc-option,-fno-ipa-cp-clone,) \
 754                  $(call cc-option,-fno-partial-inlining)
 755 endif
 756
 757 ifneq ($(CONFIG_FRAME_WARN),0)
 758 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 759 endif
 760
 761 stackp-flags-y                                    := -fno-stack-protector
 762 stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 763 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 764
 765 KBUILD_CFLAGS += $(stackp-flags-y)
 766
 767 ifdef CONFIG_CC_IS_CLANG
 768 KBUILD_CPPFLAGS += -Qunused-arguments
 769 KBUILD_CFLAGS += -Wno-format-invalid-specifier
 770 KBUILD_CFLAGS += -Wno-gnu
 771 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 772 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 773 # See modpost pattern 2
 774 KBUILD_CFLAGS += -mno-global-merge
 775 else
 776
 777 # These warnings generated too much noise in a regular build.
 778 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 779 KBUILD_CFLAGS += -Wno-unused-but-set-variable
 780
 781 # Warn about unmarked fall-throughs in switch statement.
 782 # Disabled for clang while comment to attribute conversion happens and
 783 # https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
 784 KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
 785 endif
 786
 787 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 788 ifdef CONFIG_FRAME_POINTER
 789 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 790 else
 791 # Some targets (ARM with Thumb2, for example), can't be built with frame
 792 # pointers.  For those, we don't have FUNCTION_TRACER automatically
 793 # select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 794 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
 795 # -fomit-frame-pointer with FUNCTION_TRACER.
 796 ifndef CONFIG_FUNCTION_TRACER
 797 KBUILD_CFLAGS   += -fomit-frame-pointer
 798 endif
 799 endif
 800
 801 # Initialize all stack variables with a 0xAA pattern.
 802 ifdef CONFIG_INIT_STACK_ALL_PATTERN
 803 KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 804 endif
 805
 806 # Initialize all stack variables with a zero value.
 807 ifdef CONFIG_INIT_STACK_ALL_ZERO
 808 # Future support for zero initialization is still being debated, see
 809 # https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
 810 # renamed or dropped.
 811 KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 812 KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 813 endif
 814
 815 DEBUG_CFLAGS    :=
 816
 817 # Workaround for GCC versions < 5.0
 818 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
 819 ifdef CONFIG_CC_IS_GCC
 820 DEBUG_CFLAGS    += $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
 821 endif
 822
 823 ifdef CONFIG_DEBUG_INFO
 824
 825 ifdef CONFIG_DEBUG_INFO_SPLIT
 826 DEBUG_CFLAGS    += -gsplit-dwarf
 827 else
 828 DEBUG_CFLAGS    += -g
 829 endif
 830
 831 ifneq ($(LLVM_IAS),1)
 832 KBUILD_AFLAGS   += -Wa,-gdwarf-2
 833 endif
 834
 835 ifdef CONFIG_DEBUG_INFO_DWARF4
 836 DEBUG_CFLAGS    += -gdwarf-4
 837 endif
 838
 839 ifdef CONFIG_DEBUG_INFO_REDUCED
 840 DEBUG_CFLAGS    += $(call cc-option, -femit-struct-debug-baseonly) \
 841                    $(call cc-option,-fno-var-tracking)
 842 endif
 843
 844 ifdef CONFIG_DEBUG_INFO_COMPRESSED
 845 DEBUG_CFLAGS    += -gz=zlib
 846 KBUILD_AFLAGS   += -gz=zlib
 847 KBUILD_LDFLAGS  += --compress-debug-sections=zlib
 848 endif
 849
 850 endif # CONFIG_DEBUG_INFO
 851
 852 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 853 export DEBUG_CFLAGS
 854
 855 ifdef CONFIG_FUNCTION_TRACER
 856 ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 857   CC_FLAGS_FTRACE       += -mrecord-mcount
 858   ifdef CONFIG_HAVE_NOP_MCOUNT
 859     ifeq ($(call cc-option-yn, -mnop-mcount),y)
 860       CC_FLAGS_FTRACE   += -mnop-mcount
 861       CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 862     endif
 863   endif
 864 endif
 865 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 866   CC_FLAGS_USING        += -DCC_USING_NOP_MCOUNT
 867 endif
 868 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 869   ifdef CONFIG_HAVE_C_RECORDMCOUNT
 870     BUILD_C_RECORDMCOUNT := y
 871     export BUILD_C_RECORDMCOUNT
 872   endif
 873 endif
 874 ifdef CONFIG_HAVE_FENTRY
 875   ifeq ($(call cc-option-yn, -mfentry),y)
 876     CC_FLAGS_FTRACE     += -mfentry
 877     CC_FLAGS_USING      += -DCC_USING_FENTRY
 878   endif
 879 endif
 880 export CC_FLAGS_FTRACE
 881 KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 882 KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 883 endif
 884
 885 # We trigger additional mismatches with less inlining
 886 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 887 KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 888 endif
 889
 890 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 891 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 892 LDFLAGS_vmlinux += --gc-sections
 893 endif
 894
 895 ifdef CONFIG_SHADOW_CALL_STACK
 896 CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 897 KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 898 export CC_FLAGS_SCS
 899 endif
 900
 901 ifdef CONFIG_LTO_CLANG
 902 ifdef CONFIG_LTO_CLANG_THIN
 903 CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 904 KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod-prefix).thinlto-cache
 905 else
 906 CC_FLAGS_LTO    := -flto
 907 endif
 908 CC_FLAGS_LTO    += -fvisibility=hidden
 909
 910 # Limit inlining across translation units to reduce binary size
 911 KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 912 endif
 913
 914 ifdef CONFIG_LTO
 915 KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 916 KBUILD_AFLAGS   += -fno-lto
 917 export CC_FLAGS_LTO
 918 endif
 919
 920 ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_32B
 921 KBUILD_CFLAGS += -falign-functions=32
 922 endif
 923
 924 # arch Makefile may override CC so keep this after arch Makefile is included
 925 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 926
 927 # warn about C99 declaration after statement
 928 KBUILD_CFLAGS += -Wdeclaration-after-statement
 929
 930 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 931 KBUILD_CFLAGS += -Wvla
 932
 933 # disable pointer signed / unsigned warnings in gcc 4.0
 934 KBUILD_CFLAGS += -Wno-pointer-sign
 935
 936 # disable stringop warnings in gcc 8+
 937 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 938
 939 # We'll want to enable this eventually, but it's not going away for 5.7 at least
 940 KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
 941 KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
 942 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
 943
 944 # Another good warning that we'll want to enable eventually
 945 KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 946
 947 # Enabled with W=2, disabled by default as noisy
 948 KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
 949
 950 # disable invalid "can't wrap" optimizations for signed / pointers
 951 KBUILD_CFLAGS   += -fno-strict-overflow
 952
 953 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
 954 KBUILD_CFLAGS  += -fno-stack-check
 955
 956 # conserve stack if available
 957 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
 958
 959 # Prohibit date/time macros, which would make the build non-deterministic
 960 KBUILD_CFLAGS   += -Werror=date-time
 961
 962 # enforce correct pointer usage
 963 KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
 964
 965 # Require designated initializers for all marked structures
 966 KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
 967
 968 # change __FILE__ to the relative path from the srctree
 969 KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
 970
 971 # include additional Makefiles when needed
 972 include-y                       := scripts/Makefile.extrawarn
 973 include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
 974 include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
 975 include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
 976 include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
 977 include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
 978
 979 include $(addprefix $(srctree)/, $(include-y))
 980
 981 # scripts/Makefile.gcc-plugins is intentionally included last.
 982 # Do not add $(call cc-option,...) below this line. When you build the kernel
 983 # from the clean source tree, the GCC plugins do not exist at this point.
 984
 985 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
 986 KBUILD_CPPFLAGS += $(KCPPFLAGS)
 987 KBUILD_AFLAGS   += $(KAFLAGS)
 988 KBUILD_CFLAGS   += $(KCFLAGS)
 989
 990 KBUILD_LDFLAGS_MODULE += --build-id=sha1
 991 LDFLAGS_vmlinux += --build-id=sha1
 992
 993 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
 994 LDFLAGS_vmlinux += $(call ld-option, -X,)
 995 endif
 996
 997 ifeq ($(CONFIG_RELR),y)
 998 LDFLAGS_vmlinux += --pack-dyn-relocs=relr
 999 endif
1000
1001 # We never want expected sections to be placed heuristically by the
1002 # linker. All sections should be explicitly named in the linker script.
1003 ifdef CONFIG_LD_ORPHAN_WARN
1004 LDFLAGS_vmlinux += --orphan-handling=warn
1005 endif
1006
1007 # Align the bit size of userspace programs with the kernel
1008 KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1009 KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1010
1011 # make the checker run with the right architecture
1012 CHECKFLAGS += --arch=$(ARCH)
1013
1014 # insure the checker run with the right endianness
1015 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1016
1017 # the checker needs the correct machine size
1018 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1019
1020 # Default kernel image to build when no specific target is given.
1021 # KBUILD_IMAGE may be overruled on the command line or
1022 # set in the environment
1023 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
1024 # this default value
1025 export KBUILD_IMAGE ?= vmlinux
1026
1027 #
1028 # INSTALL_PATH specifies where to place the updated kernel and system map
1029 # images. Default is /boot, but you can set it to other values
1030 export  INSTALL_PATH ?= /boot
1031
1032 #
1033 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1034 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1035 # an argument if needed. Otherwise it defaults to the kernel install path
1036 #
1037 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1038
1039 #
1040 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1041 # relocations required by build roots.  This is not defined in the
1042 # makefile but the argument can be passed to make if needed.
1043 #
1044
1045 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1046 export MODLIB
1047
1048 #
1049 # INSTALL_MOD_STRIP, if defined, will cause modules to be
1050 # stripped after they are installed.  If INSTALL_MOD_STRIP is '1', then
1051 # the default option --strip-debug will be used.  Otherwise,
1052 # INSTALL_MOD_STRIP value will be used as the options to the strip command.
1053
1054 ifdef INSTALL_MOD_STRIP
1055 ifeq ($(INSTALL_MOD_STRIP),1)
1056 mod_strip_cmd = $(STRIP) --strip-debug
1057 else
1058 mod_strip_cmd = $(STRIP) $(INSTALL_MOD_STRIP)
1059 endif # INSTALL_MOD_STRIP=1
1060 else
1061 mod_strip_cmd = true
1062 endif # INSTALL_MOD_STRIP
1063 export mod_strip_cmd
1064
1065 # CONFIG_MODULE_COMPRESS, if defined, will cause module to be compressed
1066 # after they are installed in agreement with CONFIG_MODULE_COMPRESS_GZIP
1067 # or CONFIG_MODULE_COMPRESS_XZ.
1068
1069 mod_compress_cmd = true
1070 ifdef CONFIG_MODULE_COMPRESS
1071   ifdef CONFIG_MODULE_COMPRESS_GZIP
1072     mod_compress_cmd = $(KGZIP) -n -f
1073   endif # CONFIG_MODULE_COMPRESS_GZIP
1074   ifdef CONFIG_MODULE_COMPRESS_XZ
1075     mod_compress_cmd = $(XZ) -f
1076   endif # CONFIG_MODULE_COMPRESS_XZ
1077 endif # CONFIG_MODULE_COMPRESS
1078 export mod_compress_cmd
1079
1080 ifdef CONFIG_MODULE_SIG_ALL
1081 $(eval $(call config_filename,MODULE_SIG_KEY))
1082
1083 mod_sign_cmd = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY) certs/signing_key.x509
1084 else
1085 mod_sign_cmd = true
1086 endif
1087 export mod_sign_cmd
1088
1089 HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
1090
1091 has_libelf = $(call try-run,\
1092                echo "int main() {}" | $(HOSTCC) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1093
1094 ifdef CONFIG_STACK_VALIDATION
1095   ifeq ($(has_libelf),1)
1096     objtool_target := tools/objtool FORCE
1097   else
1098     SKIP_STACK_VALIDATION := 1
1099     export SKIP_STACK_VALIDATION
1100   endif
1101 endif
1102
1103 PHONY += resolve_btfids_clean
1104
1105 resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1106
1107 # tools/bpf/resolve_btfids directory might not exist
1108 # in output directory, skip its clean in that case
1109 resolve_btfids_clean:
1110 ifneq ($(wildcard $(resolve_btfids_O)),)
1111         $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1112 endif
1113
1114 ifdef CONFIG_BPF
1115 ifdef CONFIG_DEBUG_INFO_BTF
1116   ifeq ($(has_libelf),1)
1117     resolve_btfids_target := tools/bpf/resolve_btfids FORCE
1118   else
1119     ERROR_RESOLVE_BTFIDS := 1
1120   endif
1121 endif # CONFIG_DEBUG_INFO_BTF
1122 endif # CONFIG_BPF
1123
1124 PHONY += prepare0
1125
1126 export MODORDER := $(extmod-prefix)modules.order
1127 export MODULES_NSDEPS := $(extmod-prefix)modules.nsdeps
1128
1129 ifeq ($(KBUILD_EXTMOD),)
1130 core-y          += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1131
1132 vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1133                      $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1134                      $(libs-y) $(libs-m)))
1135
1136 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1137                      $(patsubst %/,%,$(filter %/, $(core-) \
1138                         $(drivers-) $(libs-))))
1139
1140 subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1141                         $(core-y) $(core-m) $(libs-y) $(libs-m) \
1142                         $(drivers-y) $(drivers-m)))
1143
1144 build-dirs      := $(vmlinux-dirs)
1145 clean-dirs      := $(vmlinux-alldirs)
1146
1147 # Externally visible symbols (used by link-vmlinux.sh)
1148 KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1149 KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1150 ifdef CONFIG_MODULES
1151 KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1152 KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1153 else
1154 KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1155 endif
1156 KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1157
1158 export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1159 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1160 # used by scripts/Makefile.package
1161 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1162
1163 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1164
1165 # Recurse until adjust_autoksyms.sh is satisfied
1166 PHONY += autoksyms_recursive
1167 ifdef CONFIG_TRIM_UNUSED_KSYMS
1168 # For the kernel to actually contain only the needed exported symbols,
1169 # we have to build modules as well to determine what those symbols are.
1170 # (this can be evaluated only once include/config/auto.conf has been included)
1171 KBUILD_MODULES := 1
1172
1173 autoksyms_recursive: descend modules.order
1174         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1175           "$(MAKE) -f $(srctree)/Makefile vmlinux"
1176 endif
1177
1178 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1179
1180 quiet_cmd_autoksyms_h = GEN     $@
1181       cmd_autoksyms_h = mkdir -p $(dir $@); \
1182                         $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1183
1184 $(autoksyms_h):
1185         $(call cmd,autoksyms_h)
1186
1187 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1188
1189 # Final link of vmlinux with optional arch pass after final link
1190 cmd_link-vmlinux =                                                 \
1191         $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1192         $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1193
1194 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1195         +$(call if_changed,link-vmlinux)
1196
1197 targets := vmlinux
1198
1199 # The actual objects are generated when descending,
1200 # make sure no implicit rule kicks in
1201 $(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1202
1203 filechk_kernel.release = \
1204         echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1205
1206 # Store (new) KERNELRELEASE string in include/config/kernel.release
1207 include/config/kernel.release: FORCE
1208         $(call filechk,kernel.release)
1209
1210 # Additional helpers built in scripts/
1211 # Carefully list dependencies so we do not try to build scripts twice
1212 # in parallel
1213 PHONY += scripts
1214 scripts: scripts_basic scripts_dtc
1215         $(Q)$(MAKE) $(build)=$(@)
1216
1217 # Things we need to do before we recursively start building the kernel
1218 # or the modules are listed in "prepare".
1219 # A multi level approach is used. prepareN is processed before prepareN-1.
1220 # archprepare is used in arch Makefiles and when processed asm symlink,
1221 # version.h and scripts_basic is processed / created.
1222
1223 PHONY += prepare archprepare
1224
1225 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1226         asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1227         include/generated/autoconf.h
1228
1229 prepare0: archprepare
1230         $(Q)$(MAKE) $(build)=scripts/mod
1231         $(Q)$(MAKE) $(build)=.
1232
1233 # All the preparing..
1234 prepare: prepare0 prepare-objtool prepare-resolve_btfids
1235
1236 # Support for using generic headers in asm-generic
1237 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1238
1239 PHONY += asm-generic uapi-asm-generic
1240 asm-generic: uapi-asm-generic
1241         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1242         generic=include/asm-generic
1243 uapi-asm-generic:
1244         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1245         generic=include/uapi/asm-generic
1246
1247 PHONY += prepare-objtool prepare-resolve_btfids
1248 prepare-objtool: $(objtool_target)
1249 ifeq ($(SKIP_STACK_VALIDATION),1)
1250 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
1251         @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1252         @false
1253 endif
1254 ifdef CONFIG_UNWINDER_ORC
1255         @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1256         @false
1257 else
1258         @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1259 endif
1260 endif
1261
1262 prepare-resolve_btfids: $(resolve_btfids_target)
1263 ifeq ($(ERROR_RESOLVE_BTFIDS),1)
1264         @echo "error: Cannot resolve BTF IDs for CONFIG_DEBUG_INFO_BTF, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1265         @false
1266 endif
1267 # Generate some files
1268 # ---------------------------------------------------------------------------
1269
1270 # KERNELRELEASE can change from a few different places, meaning version.h
1271 # needs to be updated, so this check is forced on all builds
1272
1273 uts_len := 64
1274 define filechk_utsrelease.h
1275         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1276           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1277           exit 1;                                                         \
1278         fi;                                                               \
1279         echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1280 endef
1281
1282 define filechk_version.h
1283         echo \#define LINUX_VERSION_CODE $(shell                         \
1284         expr $(VERSION) \* 65536 + 0$(PATCHLEVEL) \* 256 + 0$(SUBLEVEL)); \
1285         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))'
1286 endef
1287
1288 $(version_h): FORCE
1289         $(call filechk,version.h)
1290         $(Q)rm -f $(old_version_h)
1291
1292 include/generated/utsrelease.h: include/config/kernel.release FORCE
1293         $(call filechk,utsrelease.h)
1294
1295 PHONY += headerdep
1296 headerdep:
1297         $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1298         $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1299
1300 # ---------------------------------------------------------------------------
1301 # Kernel headers
1302
1303 #Default location for installed headers
1304 export INSTALL_HDR_PATH = $(objtree)/usr
1305
1306 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1307       cmd_headers_install = \
1308         mkdir -p $(INSTALL_HDR_PATH); \
1309         rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1310         usr/include $(INSTALL_HDR_PATH)
1311
1312 PHONY += headers_install
1313 headers_install: headers
1314         $(call cmd,headers_install)
1315
1316 PHONY += archheaders archscripts
1317
1318 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1319
1320 PHONY += headers
1321 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1322         $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1323           $(error Headers not exportable for the $(SRCARCH) architecture))
1324         $(Q)$(MAKE) $(hdr-inst)=include/uapi
1325         $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1326
1327 # Deprecated. It is no-op now.
1328 PHONY += headers_check
1329 headers_check:
1330         @:
1331
1332 ifdef CONFIG_HEADERS_INSTALL
1333 prepare: headers
1334 endif
1335
1336 PHONY += scripts_unifdef
1337 scripts_unifdef: scripts_basic
1338         $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1339
1340 # ---------------------------------------------------------------------------
1341 # Kernel selftest
1342
1343 PHONY += kselftest
1344 kselftest:
1345         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1346
1347 kselftest-%: FORCE
1348         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1349
1350 PHONY += kselftest-merge
1351 kselftest-merge:
1352         $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1353         $(Q)find $(srctree)/tools/testing/selftests -name config | \
1354                 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1355         $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1356
1357 # ---------------------------------------------------------------------------
1358 # Devicetree files
1359
1360 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1361 dtstree := arch/$(SRCARCH)/boot/dts
1362 endif
1363
1364 ifneq ($(dtstree),)
1365
1366 %.dtb: include/config/kernel.release scripts_dtc
1367         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1368
1369 %.dtbo: include/config/kernel.release scripts_dtc
1370         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1371
1372 PHONY += dtbs dtbs_install dtbs_check
1373 dtbs: include/config/kernel.release scripts_dtc
1374         $(Q)$(MAKE) $(build)=$(dtstree)
1375
1376 ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1377 export CHECK_DTBS=y
1378 dtbs: dt_binding_check
1379 endif
1380
1381 dtbs_check: dtbs
1382
1383 dtbs_install:
1384         $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1385
1386 ifdef CONFIG_OF_EARLY_FLATTREE
1387 all: dtbs
1388 endif
1389
1390 endif
1391
1392 PHONY += scripts_dtc
1393 scripts_dtc: scripts_basic
1394         $(Q)$(MAKE) $(build)=scripts/dtc
1395
1396 ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1397 export CHECK_DT_BINDING=y
1398 endif
1399
1400 PHONY += dt_binding_check
1401 dt_binding_check: scripts_dtc
1402         $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1403
1404 # ---------------------------------------------------------------------------
1405 # Modules
1406
1407 ifdef CONFIG_MODULES
1408
1409 # By default, build modules as well
1410
1411 all: modules
1412
1413 # When we're building modules with modversions, we need to consider
1414 # the built-in objects during the descend as well, in order to
1415 # make sure the checksums are up to date before we record them.
1416 ifdef CONFIG_MODVERSIONS
1417   KBUILD_BUILTIN := 1
1418 endif
1419
1420 # Build modules
1421 #
1422 # A module can be listed more than once in obj-m resulting in
1423 # duplicate lines in modules.order files.  Those are removed
1424 # using awk while concatenating to the final file.
1425
1426 PHONY += modules
1427 modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1428         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1429
1430 PHONY += modules_check
1431 modules_check: modules.order
1432         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1433
1434 cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1435
1436 modules.order: $(subdir-modorder) FORCE
1437         $(call if_changed,modules_order)
1438
1439 targets += modules.order
1440
1441 # Target to prepare building external modules
1442 PHONY += modules_prepare
1443 modules_prepare: prepare
1444         $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1445
1446 # Target to install modules
1447 PHONY += modules_install
1448 modules_install: _modinst_ _modinst_post
1449
1450 PHONY += _modinst_
1451 _modinst_:
1452         @rm -rf $(MODLIB)/kernel
1453         @rm -f $(MODLIB)/source
1454         @mkdir -p $(MODLIB)/kernel
1455         @ln -s $(abspath $(srctree)) $(MODLIB)/source
1456         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1457                 rm -f $(MODLIB)/build ; \
1458                 ln -s $(CURDIR) $(MODLIB)/build ; \
1459         fi
1460         @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1461         @cp -f modules.builtin $(MODLIB)/
1462         @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1463         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1464
1465 # This depmod is only for convenience to give the initial
1466 # boot a modules.dep even before / is mounted read-write.  However the
1467 # boot script depmod is the master version.
1468 PHONY += _modinst_post
1469 _modinst_post: _modinst_
1470         $(call cmd,depmod)
1471
1472 ifeq ($(CONFIG_MODULE_SIG), y)
1473 PHONY += modules_sign
1474 modules_sign:
1475         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modsign
1476 endif
1477
1478 else # CONFIG_MODULES
1479
1480 # Modules not configured
1481 # ---------------------------------------------------------------------------
1482
1483 PHONY += modules modules_install
1484 modules modules_install:
1485         @echo >&2
1486         @echo >&2 "The present kernel configuration has modules disabled."
1487         @echo >&2 "Type 'make config' and enable loadable module support."
1488         @echo >&2 "Then build a kernel with module support enabled."
1489         @echo >&2
1490         @exit 1
1491
1492 endif # CONFIG_MODULES
1493
1494 ###
1495 # Cleaning is done on three levels.
1496 # make clean     Delete most generated files
1497 #                Leave enough to build external modules
1498 # make mrproper  Delete the current configuration, and all generated files
1499 # make distclean Remove editor backup files, patch leftover files and the like
1500
1501 # Directories & files removed with 'make clean'
1502 CLEAN_FILES += include/ksym vmlinux.symvers \
1503                modules.builtin modules.builtin.modinfo modules.nsdeps \
1504                compile_commands.json
1505
1506 # Directories & files removed with 'make mrproper'
1507 MRPROPER_FILES += include/config include/generated          \
1508                   arch/$(SRCARCH)/include/generated .tmp_objdiff \
1509                   debian snap tar-install \
1510                   .config .config.old .version \
1511                   Module.symvers \
1512                   signing_key.pem signing_key.priv signing_key.x509     \
1513                   x509.genkey extra_certificates signing_key.x509.keyid \
1514                   signing_key.x509.signer vmlinux-gdb.py \
1515                   *.spec
1516
1517 # Directories & files removed with 'make distclean'
1518 DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS .thinlto-cache
1519
1520 # clean - Delete most, but leave enough to build external modules
1521 #
1522 clean: rm-files := $(CLEAN_FILES)
1523
1524 PHONY += archclean vmlinuxclean
1525
1526 vmlinuxclean:
1527         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1528         $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1529
1530 clean: archclean vmlinuxclean resolve_btfids_clean
1531
1532 # mrproper - Delete all generated files, including .config
1533 #
1534 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1535 mrproper-dirs      := $(addprefix _mrproper_,scripts)
1536
1537 PHONY += $(mrproper-dirs) mrproper
1538 $(mrproper-dirs):
1539         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1540
1541 mrproper: clean $(mrproper-dirs)
1542         $(call cmd,rmfiles)
1543
1544 # distclean
1545 #
1546 distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1547
1548 PHONY += distclean
1549
1550 distclean: mrproper
1551         $(call cmd,rmfiles)
1552         @find $(srctree) $(RCS_FIND_IGNORE) \
1553                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1554                 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1555                 -o -name 'core' \) \
1556                 -type f -print | xargs rm -f
1557
1558
1559 # Packaging of the kernel to various formats
1560 # ---------------------------------------------------------------------------
1561
1562 %src-pkg: FORCE
1563         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1564 %pkg: include/config/kernel.release FORCE
1565         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1566
1567 # Brief documentation of the typical targets used
1568 # ---------------------------------------------------------------------------
1569
1570 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1571 boards := $(sort $(notdir $(boards)))
1572 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1573 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1574
1575 PHONY += help
1576 help:
1577         @echo  'Cleaning targets:'
1578         @echo  '  clean           - Remove most generated files but keep the config and'
1579         @echo  '                    enough build support to build external modules'
1580         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1581         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1582         @echo  ''
1583         @echo  'Configuration targets:'
1584         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1585         @echo  ''
1586         @echo  'Other generic targets:'
1587         @echo  '  all             - Build all targets marked with [*]'
1588         @echo  '* vmlinux         - Build the bare kernel'
1589         @echo  '* modules         - Build all modules'
1590         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1591         @echo  '  dir/            - Build all files in dir and below'
1592         @echo  '  dir/file.[ois]  - Build specified target only'
1593         @echo  '  dir/file.ll     - Build the LLVM assembly file'
1594         @echo  '                    (requires compiler support for LLVM assembly generation)'
1595         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1596         @echo  '                    (requires a recent binutils and recent build (System.map))'
1597         @echo  '  dir/file.ko     - Build module including final link'
1598         @echo  '  modules_prepare - Set up for building external modules'
1599         @echo  '  tags/TAGS       - Generate tags file for editors'
1600         @echo  '  cscope          - Generate cscope index'
1601         @echo  '  gtags           - Generate GNU GLOBAL index'
1602         @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1603         @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1604         @echo  '  image_name      - Output the image name (use with make -s)'
1605         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1606          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1607          echo  ''
1608         @echo  'Static analysers:'
1609         @echo  '  checkstack      - Generate a list of stack hogs'
1610         @echo  '  versioncheck    - Sanity check on version.h usage'
1611         @echo  '  includecheck    - Check for duplicate included header files'
1612         @echo  '  export_report   - List the usages of all exported symbols'
1613         @echo  '  headerdep       - Detect inclusion cycles in headers'
1614         @echo  '  coccicheck      - Check with Coccinelle'
1615         @echo  '  clang-analyzer  - Check with clang static analyzer'
1616         @echo  '  clang-tidy      - Check with clang-tidy'
1617         @echo  ''
1618         @echo  'Tools:'
1619         @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1620         @echo  ''
1621         @echo  'Kernel selftest:'
1622         @echo  '  kselftest         - Build and run kernel selftest'
1623         @echo  '                      Build, install, and boot kernel before'
1624         @echo  '                      running kselftest on it'
1625         @echo  '                      Run as root for full coverage'
1626         @echo  '  kselftest-all     - Build kernel selftest'
1627         @echo  '  kselftest-install - Build and install kernel selftest'
1628         @echo  '  kselftest-clean   - Remove all generated kselftest files'
1629         @echo  '  kselftest-merge   - Merge all the config dependencies of'
1630         @echo  '                      kselftest to existing .config.'
1631         @echo  ''
1632         @$(if $(dtstree), \
1633                 echo 'Devicetree:'; \
1634                 echo '* dtbs             - Build device tree blobs for enabled boards'; \
1635                 echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1636                 echo '  dt_binding_check - Validate device tree binding documents'; \
1637                 echo '  dtbs_check       - Validate device tree source files';\
1638                 echo '')
1639
1640         @echo 'Userspace tools targets:'
1641         @echo '  use "make tools/help"'
1642         @echo '  or  "cd tools; make help"'
1643         @echo  ''
1644         @echo  'Kernel packaging:'
1645         @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1646         @echo  ''
1647         @echo  'Documentation targets:'
1648         @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1649         @echo  ''
1650         @echo  'Architecture specific targets ($(SRCARCH)):'
1651         @$(if $(archhelp),$(archhelp),\
1652                 echo '  No architecture specific help defined for $(SRCARCH)')
1653         @echo  ''
1654         @$(if $(boards), \
1655                 $(foreach b, $(boards), \
1656                 printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1657                 echo '')
1658         @$(if $(board-dirs), \
1659                 $(foreach b, $(board-dirs), \
1660                 printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1661                 printf "  %-16s - Show all of the above\\n" help-boards; \
1662                 echo '')
1663
1664         @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1665         @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1666         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1667         @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1668         @echo  '                       (sparse by default)'
1669         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1670         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1671         @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1672         @echo  '                1: warnings which may be relevant and do not occur too often'
1673         @echo  '                2: warnings which occur quite often but may still be relevant'
1674         @echo  '                3: more obscure warnings, can most likely be ignored'
1675         @echo  '                Multiple levels can be combined with W=12 or W=123'
1676         @echo  ''
1677         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1678         @echo  'For further info see the ./README file'
1679
1680
1681 help-board-dirs := $(addprefix help-,$(board-dirs))
1682
1683 help-boards: $(help-board-dirs)
1684
1685 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1686
1687 $(help-board-dirs): help-%:
1688         @echo  'Architecture specific targets ($(SRCARCH) $*):'
1689         @$(if $(boards-per-dir), \
1690                 $(foreach b, $(boards-per-dir), \
1691                 printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1692                 echo '')
1693
1694
1695 # Documentation targets
1696 # ---------------------------------------------------------------------------
1697 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1698                linkcheckdocs dochelp refcheckdocs
1699 PHONY += $(DOC_TARGETS)
1700 $(DOC_TARGETS):
1701         $(Q)$(MAKE) $(build)=Documentation $@
1702
1703 # Misc
1704 # ---------------------------------------------------------------------------
1705
1706 PHONY += scripts_gdb
1707 scripts_gdb: prepare0
1708         $(Q)$(MAKE) $(build)=scripts/gdb
1709         $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1710
1711 ifdef CONFIG_GDB_SCRIPTS
1712 all: scripts_gdb
1713 endif
1714
1715 else # KBUILD_EXTMOD
1716
1717 ###
1718 # External module support.
1719 # When building external modules the kernel used as basis is considered
1720 # read-only, and no consistency checks are made and the make
1721 # system is not used on the basis kernel. If updates are required
1722 # in the basis kernel ordinary make commands (without M=...) must
1723 # be used.
1724 #
1725 # The following are the only valid targets when building external
1726 # modules.
1727 # make M=dir clean     Delete all automatically generated files
1728 # make M=dir modules   Make all modules in specified dir
1729 # make M=dir           Same as 'make M=dir modules'
1730 # make M=dir modules_install
1731 #                      Install the modules built in the module directory
1732 #                      Assumes install directory is already created
1733
1734 # We are always building only modules.
1735 KBUILD_BUILTIN :=
1736 KBUILD_MODULES := 1
1737
1738 build-dirs := $(KBUILD_EXTMOD)
1739 PHONY += modules
1740 modules: $(MODORDER)
1741         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1742
1743 $(MODORDER): descend
1744         @:
1745
1746 PHONY += modules_install
1747 modules_install: _emodinst_ _emodinst_post
1748
1749 install-dir := $(if $(INSTALL_MOD_DIR),$(INSTALL_MOD_DIR),extra)
1750 PHONY += _emodinst_
1751 _emodinst_:
1752         $(Q)mkdir -p $(MODLIB)/$(install-dir)
1753         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1754
1755 PHONY += _emodinst_post
1756 _emodinst_post: _emodinst_
1757         $(call cmd,depmod)
1758
1759 compile_commands.json: $(extmod-prefix)compile_commands.json
1760 PHONY += compile_commands.json
1761
1762 clean-dirs := $(KBUILD_EXTMOD)
1763 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1764         $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1765
1766 PHONY += help
1767 help:
1768         @echo  '  Building external modules.'
1769         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1770         @echo  ''
1771         @echo  '  modules         - default target, build the module(s)'
1772         @echo  '  modules_install - install the module'
1773         @echo  '  clean           - remove generated files in module directory only'
1774         @echo  ''
1775
1776 # no-op for external module builds
1777 PHONY += prepare modules_prepare
1778
1779 endif # KBUILD_EXTMOD
1780
1781 # Single targets
1782 # ---------------------------------------------------------------------------
1783 # To build individual files in subdirectories, you can do like this:
1784 #
1785 #   make foo/bar/baz.s
1786 #
1787 # The supported suffixes for single-target are listed in 'single-targets'
1788 #
1789 # To build only under specific subdirectories, you can do like this:
1790 #
1791 #   make foo/bar/baz/
1792
1793 ifdef single-build
1794
1795 # .ko is special because modpost is needed
1796 single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1797 single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1798
1799 $(single-ko): single_modpost
1800         @:
1801 $(single-no-ko): descend
1802         @:
1803
1804 ifeq ($(KBUILD_EXTMOD),)
1805 # For the single build of in-tree modules, use a temporary file to avoid
1806 # the situation of modules_install installing an invalid modules.order.
1807 MODORDER := .modules.tmp
1808 endif
1809
1810 PHONY += single_modpost
1811 single_modpost: $(single-no-ko) modules_prepare
1812         $(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
1813         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1814
1815 KBUILD_MODULES := 1
1816
1817 export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod-prefix), $(single-no-ko))
1818
1819 # trim unrelated directories
1820 build-dirs := $(foreach d, $(build-dirs), \
1821                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1822
1823 endif
1824
1825 ifndef CONFIG_MODULES
1826 KBUILD_MODULES :=
1827 endif
1828
1829 # Handle descending into subdirectories listed in $(build-dirs)
1830 # Preset locale variables to speed up the build process. Limit locale
1831 # tweaks to this spot to avoid wrong language settings when running
1832 # make menuconfig etc.
1833 # Error messages still appears in the original language
1834 PHONY += descend $(build-dirs)
1835 descend: $(build-dirs)
1836 $(build-dirs): prepare
1837         $(Q)$(MAKE) $(build)=$@ \
1838         single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1839         need-builtin=1 need-modorder=1
1840
1841 clean-dirs := $(addprefix _clean_, $(clean-dirs))
1842 PHONY += $(clean-dirs) clean
1843 $(clean-dirs):
1844         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1845
1846 clean: $(clean-dirs)
1847         $(call cmd,rmfiles)
1848         @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1849                 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1850                 -o -name '*.ko.*' \
1851                 -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1852                 -o -name '*.dwo' -o -name '*.lst' \
1853                 -o -name '*.su' -o -name '*.mod' \
1854                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1855                 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1856                 -o -name '*.asn1.[ch]' \
1857                 -o -name '*.symtypes' -o -name 'modules.order' \
1858                 -o -name '.tmp_*.o.*' \
1859                 -o -name '*.c.[012]*.*' \
1860                 -o -name '*.ll' \
1861                 -o -name '*.gcno' \
1862                 -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1863
1864 # Generate tags for editors
1865 # ---------------------------------------------------------------------------
1866 quiet_cmd_tags = GEN     $@
1867       cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1868
1869 tags TAGS cscope gtags: FORCE
1870         $(call cmd,tags)
1871
1872 # Script to generate missing namespace dependencies
1873 # ---------------------------------------------------------------------------
1874
1875 PHONY += nsdeps
1876 nsdeps: export KBUILD_NSDEPS=1
1877 nsdeps: modules
1878         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1879
1880 # Clang Tooling
1881 # ---------------------------------------------------------------------------
1882
1883 quiet_cmd_gen_compile_commands = GEN     $@
1884       cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1885
1886 $(extmod-prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1887         $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1888         $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1889         $(call if_changed,gen_compile_commands)
1890
1891 targets += $(extmod-prefix)compile_commands.json
1892
1893 PHONY += clang-tidy clang-analyzer
1894
1895 ifdef CONFIG_CC_IS_CLANG
1896 quiet_cmd_clang_tools = CHECK   $<
1897       cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1898
1899 clang-tidy clang-analyzer: $(extmod-prefix)compile_commands.json
1900         $(call cmd,clang_tools)
1901 else
1902 clang-tidy clang-analyzer:
1903         @echo "$@ requires CC=clang" >&2
1904         @false
1905 endif
1906
1907 # Scripts to check various things for consistency
1908 # ---------------------------------------------------------------------------
1909
1910 PHONY += includecheck versioncheck coccicheck export_report
1911
1912 includecheck:
1913         find $(srctree)/* $(RCS_FIND_IGNORE) \
1914                 -name '*.[hcS]' -type f -print | sort \
1915                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1916
1917 versioncheck:
1918         find $(srctree)/* $(RCS_FIND_IGNORE) \
1919                 -name '*.[hcS]' -type f -print | sort \
1920                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1921
1922 coccicheck:
1923         $(Q)$(BASH) $(srctree)/scripts/$@
1924
1925 export_report:
1926         $(PERL) $(srctree)/scripts/export_report.pl
1927
1928 PHONY += checkstack kernelrelease kernelversion image_name
1929
1930 # UML needs a little special treatment here.  It wants to use the host
1931 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1932 # else wants $(ARCH), including people doing cross-builds, which means
1933 # that $(SUBARCH) doesn't work here.
1934 ifeq ($(ARCH), um)
1935 CHECKSTACK_ARCH := $(SUBARCH)
1936 else
1937 CHECKSTACK_ARCH := $(ARCH)
1938 endif
1939 checkstack:
1940         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1941         $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1942
1943 kernelrelease:
1944         @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1945
1946 kernelversion:
1947         @echo $(KERNELVERSION)
1948
1949 image_name:
1950         @echo $(KBUILD_IMAGE)
1951
1952 # Clear a bunch of variables before executing the submake
1953
1954 ifeq ($(quiet),silent_)
1955 tools_silent=s
1956 endif
1957
1958 tools/: FORCE
1959         $(Q)mkdir -p $(objtree)/tools
1960         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1961
1962 tools/%: FORCE
1963         $(Q)mkdir -p $(objtree)/tools
1964         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1965
1966 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1967       cmd_rmfiles = rm -rf $(rm-files)
1968
1969 # Run depmod only if we have System.map and depmod is executable
1970 quiet_cmd_depmod = DEPMOD  $(KERNELRELEASE)
1971       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1972                    $(KERNELRELEASE)
1973
1974 # read saved command lines for existing targets
1975 existing-targets := $(wildcard $(sort $(targets)))
1976
1977 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1978
1979 endif # config-build
1980 endif # mixed-build
1981 endif # need-sub-make
1982
1983 PHONY += FORCE
1984 FORCE:
1985
1986 # Declare the contents of the PHONY variable as phony.  We keep that
1987 # information in a variable so we can use it in if_changed and friends.
1988 .PHONY: $(PHONY)