Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 VERSION = 6
   3 PATCHLEVEL = 0
   4 SUBLEVEL = 0
   5 EXTRAVERSION = -rc6
   6 NAME = Hurr durr I'ma ninja sloth
   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 --%,$(MAKEFLAGS))),)
  98   quiet=silent_
  99   KBUILD_VERBOSE = 0
 100 endif
 101
 102 export quiet Q KBUILD_VERBOSE
 103
 104 # Call a source code checker (by default, "sparse") as part of the
 105 # C compilation.
 106 #
 107 # Use 'make C=1' to enable checking of only re-compiled files.
 108 # Use 'make C=2' to enable checking of *all* source files, regardless
 109 # of whether they are re-compiled or not.
 110 #
 111 # See the file "Documentation/dev-tools/sparse.rst" for more details,
 112 # including where to get the "sparse" utility.
 113
 114 ifeq ("$(origin C)", "command line")
 115   KBUILD_CHECKSRC = $(C)
 116 endif
 117 ifndef KBUILD_CHECKSRC
 118   KBUILD_CHECKSRC = 0
 119 endif
 120
 121 export KBUILD_CHECKSRC
 122
 123 # Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
 124 # directory of external module to build. Setting M= takes precedence.
 125 ifeq ("$(origin M)", "command line")
 126   KBUILD_EXTMOD := $(M)
 127 endif
 128
 129 $(if $(word 2, $(KBUILD_EXTMOD)), \
 130         $(error building multiple external modules is not supported))
 131
 132 $(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
 133         $(error module directory path cannot contain '$x')))
 134
 135 # Remove trailing slashes
 136 ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
 137 KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
 138 endif
 139
 140 export KBUILD_EXTMOD
 141
 142 # Kbuild will save output files in the current working directory.
 143 # This does not need to match to the root of the kernel source tree.
 144 #
 145 # For example, you can do this:
 146 #
 147 #  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
 148 #
 149 # If you want to save output files in a different location, there are
 150 # two syntaxes to specify it.
 151 #
 152 # 1) O=
 153 # Use "make O=dir/to/store/output/files/"
 154 #
 155 # 2) Set KBUILD_OUTPUT
 156 # Set the environment variable KBUILD_OUTPUT to point to the output directory.
 157 # export KBUILD_OUTPUT=dir/to/store/output/files/; make
 158 #
 159 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
 160 # variable.
 161
 162 # Do we want to change the working directory?
 163 ifeq ("$(origin O)", "command line")
 164   KBUILD_OUTPUT := $(O)
 165 endif
 166
 167 ifneq ($(KBUILD_OUTPUT),)
 168 # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
 169 # expand a shell special character '~'. We use a somewhat tedious way here.
 170 abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
 171 $(if $(abs_objtree),, \
 172      $(error failed to create output directory "$(KBUILD_OUTPUT)"))
 173
 174 # $(realpath ...) resolves symlinks
 175 abs_objtree := $(realpath $(abs_objtree))
 176 else
 177 abs_objtree := $(CURDIR)
 178 endif # ifneq ($(KBUILD_OUTPUT),)
 179
 180 ifeq ($(abs_objtree),$(CURDIR))
 181 # Suppress "Entering directory ..." unless we are changing the work directory.
 182 MAKEFLAGS += --no-print-directory
 183 else
 184 need-sub-make := 1
 185 endif
 186
 187 this-makefile := $(lastword $(MAKEFILE_LIST))
 188 abs_srctree := $(realpath $(dir $(this-makefile)))
 189
 190 ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
 191 $(error source directory cannot contain spaces or colons)
 192 endif
 193
 194 ifneq ($(abs_srctree),$(abs_objtree))
 195 # Look for make include files relative to root of kernel src
 196 #
 197 # --included-dir is added for backward compatibility, but you should not rely on
 198 # it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
 199 MAKEFLAGS += --include-dir=$(abs_srctree)
 200 endif
 201
 202 ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 203 # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
 204 # We need to invoke sub-make to avoid implicit rules in the top Makefile.
 205 need-sub-make := 1
 206 # Cancel implicit rules for this Makefile.
 207 $(this-makefile): ;
 208 endif
 209
 210 export abs_srctree abs_objtree
 211 export sub_make_done := 1
 212
 213 ifeq ($(need-sub-make),1)
 214
 215 PHONY += $(MAKECMDGOALS) __sub-make
 216
 217 $(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 218         @:
 219
 220 # Invoke a second make in the output directory, passing relevant variables
 221 __sub-make:
 222         $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 223
 224 endif # need-sub-make
 225 endif # sub_make_done
 226
 227 # We process the rest of the Makefile if this is the final invocation of make
 228 ifeq ($(need-sub-make),)
 229
 230 # Do not print "Entering directory ...",
 231 # but we want to display it when entering to the output directory
 232 # so that IDEs/editors are able to understand relative filenames.
 233 MAKEFLAGS += --no-print-directory
 234
 235 ifeq ($(abs_srctree),$(abs_objtree))
 236         # building in the source tree
 237         srctree := .
 238         building_out_of_srctree :=
 239 else
 240         ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
 241                 # building in a subdirectory of the source tree
 242                 srctree := ..
 243         else
 244                 srctree := $(abs_srctree)
 245         endif
 246         building_out_of_srctree := 1
 247 endif
 248
 249 ifneq ($(KBUILD_ABS_SRCTREE),)
 250 srctree := $(abs_srctree)
 251 endif
 252
 253 objtree         := .
 254 VPATH           := $(srctree)
 255
 256 export building_out_of_srctree srctree objtree VPATH
 257
 258 # To make sure we do not include .config for any of the *config targets
 259 # catch them early, and hand them over to scripts/kconfig/Makefile
 260 # It is allowed to specify more targets when calling make, including
 261 # mixing *config targets and build targets.
 262 # For example 'make oldconfig all'.
 263 # Detect when mixed targets is specified, and make a second invocation
 264 # of make so .config is not included in this case either (for *config).
 265
 266 version_h := include/generated/uapi/linux/version.h
 267
 268 clean-targets := %clean mrproper cleandocs
 269 no-dot-config-targets := $(clean-targets) \
 270                          cscope gtags TAGS tags help% %docs check% coccicheck \
 271                          $(version_h) headers headers_% archheaders archscripts \
 272                          %asm-generic kernelversion %src-pkg dt_binding_check \
 273                          outputmakefile
 274 # Installation targets should not require compiler. Unfortunately, vdso_install
 275 # is an exception where build artifacts may be updated. This must be fixed.
 276 no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
 277                         headers_install modules_install kernelrelease image_name
 278 no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
 279                           image_name
 280 single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
 281
 282 config-build    :=
 283 mixed-build     :=
 284 need-config     := 1
 285 need-compiler   := 1
 286 may-sync-config := 1
 287 single-build    :=
 288
 289 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 290         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 291                 need-config :=
 292         endif
 293 endif
 294
 295 ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
 296         ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
 297                 need-compiler :=
 298         endif
 299 endif
 300
 301 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 302         ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 303                 may-sync-config :=
 304         endif
 305 endif
 306
 307 ifneq ($(KBUILD_EXTMOD),)
 308         may-sync-config :=
 309 endif
 310
 311 ifeq ($(KBUILD_EXTMOD),)
 312         ifneq ($(filter %config,$(MAKECMDGOALS)),)
 313                 config-build := 1
 314                 ifneq ($(words $(MAKECMDGOALS)),1)
 315                         mixed-build := 1
 316                 endif
 317         endif
 318 endif
 319
 320 # We cannot build single targets and the others at the same time
 321 ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 322         single-build := 1
 323         ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 324                 mixed-build := 1
 325         endif
 326 endif
 327
 328 # For "make -j clean all", "make -j mrproper defconfig all", etc.
 329 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 330         ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 331                 mixed-build := 1
 332         endif
 333 endif
 334
 335 # install and modules_install need also be processed one by one
 336 ifneq ($(filter install,$(MAKECMDGOALS)),)
 337         ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 338                 mixed-build := 1
 339         endif
 340 endif
 341
 342 ifdef mixed-build
 343 # ===========================================================================
 344 # We're called with mixed targets (*config and build targets).
 345 # Handle them one by one.
 346
 347 PHONY += $(MAKECMDGOALS) __build_one_by_one
 348
 349 $(MAKECMDGOALS): __build_one_by_one
 350         @:
 351
 352 __build_one_by_one:
 353         $(Q)set -e; \
 354         for i in $(MAKECMDGOALS); do \
 355                 $(MAKE) -f $(srctree)/Makefile $$i; \
 356         done
 357
 358 else # !mixed-build
 359
 360 include $(srctree)/scripts/Kbuild.include
 361
 362 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 363 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 364 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 365 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 366
 367 include $(srctree)/scripts/subarch.include
 368
 369 # Cross compiling and selecting different set of gcc/bin-utils
 370 # ---------------------------------------------------------------------------
 371 #
 372 # When performing cross compilation for other architectures ARCH shall be set
 373 # to the target architecture. (See arch/* for the possibilities).
 374 # ARCH can be set during invocation of make:
 375 # make ARCH=ia64
 376 # Another way is to have ARCH set in the environment.
 377 # The default ARCH is the host where make is executed.
 378
 379 # CROSS_COMPILE specify the prefix used for all executables used
 380 # during compilation. Only gcc and related bin-utils executables
 381 # are prefixed with $(CROSS_COMPILE).
 382 # CROSS_COMPILE can be set on the command line
 383 # make CROSS_COMPILE=ia64-linux-
 384 # Alternatively CROSS_COMPILE can be set in the environment.
 385 # Default value for CROSS_COMPILE is not to prefix executables
 386 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 387 ARCH            ?= $(SUBARCH)
 388
 389 # Architecture as present in compile.h
 390 UTS_MACHINE     := $(ARCH)
 391 SRCARCH         := $(ARCH)
 392
 393 # Additional ARCH settings for x86
 394 ifeq ($(ARCH),i386)
 395         SRCARCH := x86
 396 endif
 397 ifeq ($(ARCH),x86_64)
 398         SRCARCH := x86
 399 endif
 400
 401 # Additional ARCH settings for sparc
 402 ifeq ($(ARCH),sparc32)
 403        SRCARCH := sparc
 404 endif
 405 ifeq ($(ARCH),sparc64)
 406        SRCARCH := sparc
 407 endif
 408
 409 # Additional ARCH settings for parisc
 410 ifeq ($(ARCH),parisc64)
 411        SRCARCH := parisc
 412 endif
 413
 414 export cross_compiling :=
 415 ifneq ($(SRCARCH),$(SUBARCH))
 416 cross_compiling := 1
 417 endif
 418
 419 KCONFIG_CONFIG  ?= .config
 420 export KCONFIG_CONFIG
 421
 422 # SHELL used by kbuild
 423 CONFIG_SHELL := sh
 424
 425 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 426 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 427 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 428
 429 ifneq ($(LLVM),)
 430 ifneq ($(filter %/,$(LLVM)),)
 431 LLVM_PREFIX := $(LLVM)
 432 else ifneq ($(filter -%,$(LLVM)),)
 433 LLVM_SUFFIX := $(LLVM)
 434 endif
 435
 436 HOSTCC  = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
 437 HOSTCXX = $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
 438 else
 439 HOSTCC  = gcc
 440 HOSTCXX = g++
 441 endif
 442 HOSTPKG_CONFIG  = pkg-config
 443
 444 KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 445                          -O2 -fomit-frame-pointer -std=gnu11 \
 446                          -Wdeclaration-after-statement
 447 KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
 448 KBUILD_USERLDFLAGS := $(USERLDFLAGS)
 449
 450 KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 451 KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 452 KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 453 KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 454
 455 # Make variables (CC, etc...)
 456 CPP             = $(CC) -E
 457 ifneq ($(LLVM),)
 458 CC              = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
 459 LD              = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
 460 AR              = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
 461 NM              = $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
 462 OBJCOPY         = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
 463 OBJDUMP         = $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
 464 READELF         = $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
 465 STRIP           = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
 466 else
 467 CC              = $(CROSS_COMPILE)gcc
 468 LD              = $(CROSS_COMPILE)ld
 469 AR              = $(CROSS_COMPILE)ar
 470 NM              = $(CROSS_COMPILE)nm
 471 OBJCOPY         = $(CROSS_COMPILE)objcopy
 472 OBJDUMP         = $(CROSS_COMPILE)objdump
 473 READELF         = $(CROSS_COMPILE)readelf
 474 STRIP           = $(CROSS_COMPILE)strip
 475 endif
 476 PAHOLE          = pahole
 477 RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 478 LEX             = flex
 479 YACC            = bison
 480 AWK             = awk
 481 INSTALLKERNEL  := installkernel
 482 DEPMOD          = depmod
 483 PERL            = perl
 484 PYTHON3         = python3
 485 CHECK           = sparse
 486 BASH            = bash
 487 KGZIP           = gzip
 488 KBZIP2          = bzip2
 489 KLZOP           = lzop
 490 LZMA            = lzma
 491 LZ4             = lz4c
 492 XZ              = xz
 493 ZSTD            = zstd
 494
 495 PAHOLE_FLAGS    = $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
 496
 497 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 498                   -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 499 NOSTDINC_FLAGS :=
 500 CFLAGS_MODULE   =
 501 AFLAGS_MODULE   =
 502 LDFLAGS_MODULE  =
 503 CFLAGS_KERNEL   =
 504 AFLAGS_KERNEL   =
 505 LDFLAGS_vmlinux =
 506
 507 # Use USERINCLUDE when you must reference the UAPI directories only.
 508 USERINCLUDE    := \
 509                 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 510                 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 511                 -I$(srctree)/include/uapi \
 512                 -I$(objtree)/include/generated/uapi \
 513                 -include $(srctree)/include/linux/compiler-version.h \
 514                 -include $(srctree)/include/linux/kconfig.h
 515
 516 # Use LINUXINCLUDE when you must reference the include/ directory.
 517 # Needed to be compatible with the O= option
 518 LINUXINCLUDE    := \
 519                 -I$(srctree)/arch/$(SRCARCH)/include \
 520                 -I$(objtree)/arch/$(SRCARCH)/include/generated \
 521                 $(if $(building_out_of_srctree),-I$(srctree)/include) \
 522                 -I$(objtree)/include \
 523                 $(USERINCLUDE)
 524
 525 KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 526 KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 527                    -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 528                    -Werror=implicit-function-declaration -Werror=implicit-int \
 529                    -Werror=return-type -Wno-format-security \
 530                    -std=gnu11
 531 KBUILD_CPPFLAGS := -D__KERNEL__
 532 KBUILD_AFLAGS_KERNEL :=
 533 KBUILD_CFLAGS_KERNEL :=
 534 KBUILD_AFLAGS_MODULE  := -DMODULE
 535 KBUILD_CFLAGS_MODULE  := -DMODULE
 536 KBUILD_LDFLAGS_MODULE :=
 537 KBUILD_LDFLAGS :=
 538 CLANG_FLAGS :=
 539
 540 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
 541 export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 542 export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 543 export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 544 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 545 export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
 546
 547 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 548 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 549 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 550 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 551 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 552 export PAHOLE_FLAGS
 553
 554 # Files to ignore in find ... statements
 555
 556 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 557                           -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 558                           -prune -o
 559 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 560                          --exclude CVS --exclude .pc --exclude .hg --exclude .git
 561
 562 # ===========================================================================
 563 # Rules shared between *config targets and build targets
 564
 565 # Basic helpers built in scripts/basic/
 566 PHONY += scripts_basic
 567 scripts_basic:
 568         $(Q)$(MAKE) $(build)=scripts/basic
 569
 570 PHONY += outputmakefile
 571 ifdef building_out_of_srctree
 572 # Before starting out-of-tree build, make sure the source tree is clean.
 573 # outputmakefile generates a Makefile in the output directory, if using a
 574 # separate output directory. This allows convenient use of make in the
 575 # output directory.
 576 # At the same time when output Makefile generated, generate .gitignore to
 577 # ignore whole output directory
 578
 579 quiet_cmd_makefile = GEN     Makefile
 580       cmd_makefile = { \
 581         echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
 582         echo "include $(srctree)/Makefile"; \
 583         } > Makefile
 584
 585 outputmakefile:
 586         $(Q)if [ -f $(srctree)/.config -o \
 587                  -d $(srctree)/include/config -o \
 588                  -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 589                 echo >&2 "***"; \
 590                 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 591                 echo >&2 "*** in $(abs_srctree)";\
 592                 echo >&2 "***"; \
 593                 false; \
 594         fi
 595         $(Q)ln -fsn $(srctree) source
 596         $(call cmd,makefile)
 597         $(Q)test -e .gitignore || \
 598         { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 599 endif
 600
 601 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 602 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 603 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 604 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
 605 CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
 606
 607 ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 608 include $(srctree)/scripts/Makefile.clang
 609 endif
 610
 611 # Include this also for config targets because some architectures need
 612 # cc-cross-prefix to determine CROSS_COMPILE.
 613 ifdef need-compiler
 614 include $(srctree)/scripts/Makefile.compiler
 615 endif
 616
 617 ifdef config-build
 618 # ===========================================================================
 619 # *config targets only - make sure prerequisites are updated, and descend
 620 # in scripts/kconfig to make the *config target
 621
 622 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 623 # KBUILD_DEFCONFIG may point out an alternative default configuration
 624 # used for 'make defconfig'
 625 include $(srctree)/arch/$(SRCARCH)/Makefile
 626 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 627
 628 config: outputmakefile scripts_basic FORCE
 629         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 630
 631 %config: outputmakefile scripts_basic FORCE
 632         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 633
 634 else #!config-build
 635 # ===========================================================================
 636 # Build targets only - this includes vmlinux, arch specific targets, clean
 637 # targets and others. In general all targets except *config targets.
 638
 639 # If building an external module we do not care about the all: rule
 640 # but instead __all depend on modules
 641 PHONY += all
 642 ifeq ($(KBUILD_EXTMOD),)
 643 __all: all
 644 else
 645 __all: modules
 646 endif
 647
 648 # Decide whether to build built-in, modular, or both.
 649 # Normally, just do built-in.
 650
 651 KBUILD_MODULES :=
 652 KBUILD_BUILTIN := 1
 653
 654 # If we have only "make modules", don't compile built-in objects.
 655 ifeq ($(MAKECMDGOALS),modules)
 656   KBUILD_BUILTIN :=
 657 endif
 658
 659 # If we have "make <whatever> modules", compile modules
 660 # in addition to whatever we do anyway.
 661 # Just "make" or "make all" shall build modules as well
 662
 663 ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 664   KBUILD_MODULES := 1
 665 endif
 666
 667 ifeq ($(MAKECMDGOALS),)
 668   KBUILD_MODULES := 1
 669 endif
 670
 671 export KBUILD_MODULES KBUILD_BUILTIN
 672
 673 ifdef need-config
 674 include include/config/auto.conf
 675 endif
 676
 677 ifeq ($(KBUILD_EXTMOD),)
 678 # Objects we will link into vmlinux / subdirs we need to visit
 679 core-y          := init/ usr/ arch/$(SRCARCH)/
 680 drivers-y       := drivers/ sound/
 681 drivers-$(CONFIG_SAMPLES) += samples/
 682 drivers-$(CONFIG_NET) += net/
 683 drivers-y       += virt/
 684 libs-y          := lib/
 685 endif # KBUILD_EXTMOD
 686
 687 # The all: target is the default when no target is given on the
 688 # command line.
 689 # This allow a user to issue only 'make' to build a kernel including modules
 690 # Defaults to vmlinux, but the arch makefile usually adds further targets
 691 all: vmlinux
 692
 693 CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage
 694 ifdef CONFIG_CC_IS_GCC
 695 CFLAGS_GCOV     += -fno-tree-loop-im
 696 endif
 697 export CFLAGS_GCOV
 698
 699 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 700 ifdef CONFIG_FUNCTION_TRACER
 701   CC_FLAGS_FTRACE := -pg
 702 endif
 703
 704 include $(srctree)/arch/$(SRCARCH)/Makefile
 705
 706 ifdef need-config
 707 ifdef may-sync-config
 708 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 709 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 710 # because some architectures define CROSS_COMPILE there.
 711 include include/config/auto.conf.cmd
 712
 713 $(KCONFIG_CONFIG):
 714         @echo >&2 '***'
 715         @echo >&2 '*** Configuration file "$@" not found!'
 716         @echo >&2 '***'
 717         @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 718         @echo >&2 '*** "make menuconfig" or "make xconfig").'
 719         @echo >&2 '***'
 720         @/bin/false
 721
 722 # The actual configuration files used during the build are stored in
 723 # include/generated/ and include/config/. Update them if .config is newer than
 724 # include/config/auto.conf (which mirrors .config).
 725 #
 726 # This exploits the 'multi-target pattern rule' trick.
 727 # The syncconfig should be executed only once to make all the targets.
 728 # (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 729 #
 730 # Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
 731 # so you cannot notice that Kconfig is waiting for the user input.
 732 %/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 733         $(Q)$(kecho) "  SYNC    $@"
 734         $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
 735 else # !may-sync-config
 736 # External modules and some install targets need include/generated/autoconf.h
 737 # and include/config/auto.conf but do not care if they are up-to-date.
 738 # Use auto.conf to trigger the test
 739 PHONY += include/config/auto.conf
 740
 741 include/config/auto.conf:
 742         $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 743         echo >&2;                                                       \
 744         echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 745         echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 746         echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 747         echo >&2 ;                                                      \
 748         /bin/false)
 749
 750 endif # may-sync-config
 751 endif # need-config
 752
 753 KBUILD_CFLAGS   += -fno-delete-null-pointer-checks
 754 KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 755 KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 756 KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 757 KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 758
 759 ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 760 KBUILD_CFLAGS += -O2
 761 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 762 KBUILD_CFLAGS += -Os
 763 endif
 764
 765 # Tell gcc to never replace conditional load with a non-conditional one
 766 ifdef CONFIG_CC_IS_GCC
 767 # gcc-10 renamed --param=allow-store-data-races=0 to
 768 # -fno-allow-store-data-races.
 769 KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 770 KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 771 endif
 772
 773 ifdef CONFIG_READABLE_ASM
 774 # Disable optimizations that make assembler listings hard to read.
 775 # reorder blocks reorders the control in the function
 776 # ipa clone creates specialized cloned functions
 777 # partial inlining inlines only parts of functions
 778 KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
 779 endif
 780
 781 ifneq ($(CONFIG_FRAME_WARN),0)
 782 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 783 endif
 784
 785 stackp-flags-y                                    := -fno-stack-protector
 786 stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 787 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 788
 789 KBUILD_CFLAGS += $(stackp-flags-y)
 790
 791 KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
 792 KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
 793 KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
 794
 795 ifdef CONFIG_CC_IS_CLANG
 796 KBUILD_CPPFLAGS += -Qunused-arguments
 797 # The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
 798 KBUILD_CFLAGS += -Wno-gnu
 799 else
 800
 801 # gcc inanely warns about local variables called 'main'
 802 KBUILD_CFLAGS += -Wno-main
 803 endif
 804
 805 # These warnings generated too much noise in a regular build.
 806 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 807 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 808 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 809
 810 # These result in bogus false positives
 811 KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
 812
 813 ifdef CONFIG_FRAME_POINTER
 814 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 815 else
 816 # Some targets (ARM with Thumb2, for example), can't be built with frame
 817 # pointers.  For those, we don't have FUNCTION_TRACER automatically
 818 # select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 819 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
 820 # -fomit-frame-pointer with FUNCTION_TRACER.
 821 ifndef CONFIG_FUNCTION_TRACER
 822 KBUILD_CFLAGS   += -fomit-frame-pointer
 823 endif
 824 endif
 825
 826 # Initialize all stack variables with a 0xAA pattern.
 827 ifdef CONFIG_INIT_STACK_ALL_PATTERN
 828 KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 829 endif
 830
 831 # Initialize all stack variables with a zero value.
 832 ifdef CONFIG_INIT_STACK_ALL_ZERO
 833 KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 834 ifdef CONFIG_CC_IS_CLANG
 835 # https://bugs.llvm.org/show_bug.cgi?id=45497
 836 KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 837 endif
 838 endif
 839
 840 # While VLAs have been removed, GCC produces unreachable stack probes
 841 # for the randomize_kstack_offset feature. Disable it for all compilers.
 842 KBUILD_CFLAGS   += $(call cc-option, -fno-stack-clash-protection)
 843
 844 # Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
 845 ifdef CONFIG_ZERO_CALL_USED_REGS
 846 KBUILD_CFLAGS   += -fzero-call-used-regs=used-gpr
 847 endif
 848
 849 ifdef CONFIG_FUNCTION_TRACER
 850 ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 851   CC_FLAGS_FTRACE       += -mrecord-mcount
 852   ifdef CONFIG_HAVE_NOP_MCOUNT
 853     ifeq ($(call cc-option-yn, -mnop-mcount),y)
 854       CC_FLAGS_FTRACE   += -mnop-mcount
 855       CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 856     endif
 857   endif
 858 endif
 859 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 860   CC_FLAGS_USING        += -DCC_USING_NOP_MCOUNT
 861 endif
 862 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 863   ifdef CONFIG_HAVE_C_RECORDMCOUNT
 864     BUILD_C_RECORDMCOUNT := y
 865     export BUILD_C_RECORDMCOUNT
 866   endif
 867 endif
 868 ifdef CONFIG_HAVE_FENTRY
 869   # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
 870   ifeq ($(call cc-option-yn, -mfentry),y)
 871     CC_FLAGS_FTRACE     += -mfentry
 872     CC_FLAGS_USING      += -DCC_USING_FENTRY
 873   endif
 874 endif
 875 export CC_FLAGS_FTRACE
 876 KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 877 KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 878 endif
 879
 880 # We trigger additional mismatches with less inlining
 881 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 882 KBUILD_CFLAGS += -fno-inline-functions-called-once
 883 endif
 884
 885 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 886 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 887 LDFLAGS_vmlinux += --gc-sections
 888 endif
 889
 890 ifdef CONFIG_SHADOW_CALL_STACK
 891 CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 892 KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 893 export CC_FLAGS_SCS
 894 endif
 895
 896 ifdef CONFIG_LTO_CLANG
 897 ifdef CONFIG_LTO_CLANG_THIN
 898 CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 899 KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
 900 else
 901 CC_FLAGS_LTO    := -flto
 902 endif
 903 CC_FLAGS_LTO    += -fvisibility=hidden
 904
 905 # Limit inlining across translation units to reduce binary size
 906 KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 907
 908 # Check for frame size exceeding threshold during prolog/epilog insertion
 909 # when using lld < 13.0.0.
 910 ifneq ($(CONFIG_FRAME_WARN),0)
 911 ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
 912 KBUILD_LDFLAGS  += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 913 endif
 914 endif
 915 endif
 916
 917 ifdef CONFIG_LTO
 918 KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 919 KBUILD_AFLAGS   += -fno-lto
 920 export CC_FLAGS_LTO
 921 endif
 922
 923 ifdef CONFIG_CFI_CLANG
 924 CC_FLAGS_CFI    := -fsanitize=cfi \
 925                    -fsanitize-cfi-cross-dso \
 926                    -fno-sanitize-cfi-canonical-jump-tables \
 927                    -fno-sanitize-trap=cfi \
 928                    -fno-sanitize-blacklist
 929
 930 ifdef CONFIG_CFI_PERMISSIVE
 931 CC_FLAGS_CFI    += -fsanitize-recover=cfi
 932 endif
 933
 934 # If LTO flags are filtered out, we must also filter out CFI.
 935 CC_FLAGS_LTO    += $(CC_FLAGS_CFI)
 936 KBUILD_CFLAGS   += $(CC_FLAGS_CFI)
 937 export CC_FLAGS_CFI
 938 endif
 939
 940 ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
 941 KBUILD_CFLAGS += -falign-functions=64
 942 endif
 943
 944 # arch Makefile may override CC so keep this after arch Makefile is included
 945 NOSTDINC_FLAGS += -nostdinc
 946
 947 # warn about C99 declaration after statement
 948 KBUILD_CFLAGS += -Wdeclaration-after-statement
 949
 950 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 951 KBUILD_CFLAGS += -Wvla
 952
 953 # disable pointer signed / unsigned warnings in gcc 4.0
 954 KBUILD_CFLAGS += -Wno-pointer-sign
 955
 956 # In order to make sure new function cast mismatches are not introduced
 957 # in the kernel (to avoid tripping CFI checking), the kernel should be
 958 # globally built with -Wcast-function-type.
 959 KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
 960
 961 # disable stringop warnings in gcc 8+
 962 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 963
 964 # We'll want to enable this eventually, but it's not going away for 5.7 at least
 965 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
 966
 967 # Another good warning that we'll want to enable eventually
 968 KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 969
 970 # Enabled with W=2, disabled by default as noisy
 971 ifdef CONFIG_CC_IS_GCC
 972 KBUILD_CFLAGS += -Wno-maybe-uninitialized
 973 endif
 974
 975 ifdef CONFIG_CC_IS_GCC
 976 # The allocators already balk at large sizes, so silence the compiler
 977 # warnings for bounds checks involving those possible values. While
 978 # -Wno-alloc-size-larger-than would normally be used here, earlier versions
 979 # of gcc (<9.1) weirdly don't handle the option correctly when _other_
 980 # warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
 981 # doesn't work (as it is documented to), silently resolving to "0" prior to
 982 # version 9.1 (and producing an error more recently). Numeric values larger
 983 # than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
 984 # ignored, continuing to default to PTRDIFF_MAX. So, left with no other
 985 # choice, we must perform a versioned check to disable this warning.
 986 # https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
 987 KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
 988 endif
 989
 990 # disable invalid "can't wrap" optimizations for signed / pointers
 991 KBUILD_CFLAGS   += -fno-strict-overflow
 992
 993 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
 994 KBUILD_CFLAGS  += -fno-stack-check
 995
 996 # conserve stack if available
 997 ifdef CONFIG_CC_IS_GCC
 998 KBUILD_CFLAGS   += -fconserve-stack
 999 endif
1000
1001 # Prohibit date/time macros, which would make the build non-deterministic
1002 KBUILD_CFLAGS   += -Werror=date-time
1003
1004 # enforce correct pointer usage
1005 KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1006
1007 # Require designated initializers for all marked structures
1008 KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1009
1010 # change __FILE__ to the relative path from the srctree
1011 KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1012
1013 # include additional Makefiles when needed
1014 include-y                       := scripts/Makefile.extrawarn
1015 include-$(CONFIG_DEBUG_INFO)    += scripts/Makefile.debug
1016 include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
1017 include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
1018 include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
1019 include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
1020 include-$(CONFIG_RANDSTRUCT)    += scripts/Makefile.randstruct
1021 include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
1022
1023 include $(addprefix $(srctree)/, $(include-y))
1024
1025 # scripts/Makefile.gcc-plugins is intentionally included last.
1026 # Do not add $(call cc-option,...) below this line. When you build the kernel
1027 # from the clean source tree, the GCC plugins do not exist at this point.
1028
1029 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1030 KBUILD_CPPFLAGS += $(KCPPFLAGS)
1031 KBUILD_AFLAGS   += $(KAFLAGS)
1032 KBUILD_CFLAGS   += $(KCFLAGS)
1033
1034 KBUILD_LDFLAGS_MODULE += --build-id=sha1
1035 LDFLAGS_vmlinux += --build-id=sha1
1036
1037 KBUILD_LDFLAGS  += -z noexecstack
1038 ifeq ($(CONFIG_LD_IS_BFD),y)
1039 KBUILD_LDFLAGS  += $(call ld-option,--no-warn-rwx-segments)
1040 endif
1041
1042 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1043 LDFLAGS_vmlinux += $(call ld-option, -X,)
1044 endif
1045
1046 ifeq ($(CONFIG_RELR),y)
1047 LDFLAGS_vmlinux += --pack-dyn-relocs=relr --use-android-relr-tags
1048 endif
1049
1050 # We never want expected sections to be placed heuristically by the
1051 # linker. All sections should be explicitly named in the linker script.
1052 ifdef CONFIG_LD_ORPHAN_WARN
1053 LDFLAGS_vmlinux += --orphan-handling=warn
1054 endif
1055
1056 # Align the bit size of userspace programs with the kernel
1057 KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1058 KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1059
1060 # make the checker run with the right architecture
1061 CHECKFLAGS += --arch=$(ARCH)
1062
1063 # insure the checker run with the right endianness
1064 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1065
1066 # the checker needs the correct machine size
1067 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1068
1069 # Default kernel image to build when no specific target is given.
1070 # KBUILD_IMAGE may be overruled on the command line or
1071 # set in the environment
1072 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
1073 # this default value
1074 export KBUILD_IMAGE ?= vmlinux
1075
1076 #
1077 # INSTALL_PATH specifies where to place the updated kernel and system map
1078 # images. Default is /boot, but you can set it to other values
1079 export  INSTALL_PATH ?= /boot
1080
1081 #
1082 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1083 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1084 # an argument if needed. Otherwise it defaults to the kernel install path
1085 #
1086 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1087
1088 #
1089 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1090 # relocations required by build roots.  This is not defined in the
1091 # makefile but the argument can be passed to make if needed.
1092 #
1093
1094 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1095 export MODLIB
1096
1097 PHONY += prepare0
1098
1099 export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1100 export MODORDER := $(extmod_prefix)modules.order
1101 export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1102
1103 ifeq ($(KBUILD_EXTMOD),)
1104 core-y                  += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
1105 core-$(CONFIG_BLOCK)    += block/
1106 core-$(CONFIG_IO_URING) += io_uring/
1107
1108 vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1109                      $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1110                      $(libs-y) $(libs-m)))
1111
1112 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1113                      $(patsubst %/,%,$(filter %/, $(core-) \
1114                         $(drivers-) $(libs-))))
1115
1116 build-dirs      := $(vmlinux-dirs)
1117 clean-dirs      := $(vmlinux-alldirs)
1118
1119 subdir-modorder := $(addsuffix /modules.order, $(build-dirs))
1120
1121 # Externally visible symbols (used by link-vmlinux.sh)
1122 KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1123 KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1124 ifdef CONFIG_MODULES
1125 KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1126 KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1127 else
1128 KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1129 endif
1130 KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1131
1132 export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1133 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1134 # used by scripts/Makefile.package
1135 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1136
1137 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1138
1139 # Recurse until adjust_autoksyms.sh is satisfied
1140 PHONY += autoksyms_recursive
1141 ifdef CONFIG_TRIM_UNUSED_KSYMS
1142 # For the kernel to actually contain only the needed exported symbols,
1143 # we have to build modules as well to determine what those symbols are.
1144 # (this can be evaluated only once include/config/auto.conf has been included)
1145 KBUILD_MODULES := 1
1146
1147 autoksyms_recursive: descend modules.order
1148         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1149           "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
1150 endif
1151
1152 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1153
1154 quiet_cmd_autoksyms_h = GEN     $@
1155       cmd_autoksyms_h = mkdir -p $(dir $@); \
1156                         $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1157
1158 $(autoksyms_h):
1159         $(call cmd,autoksyms_h)
1160
1161 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1162
1163 # Final link of vmlinux with optional arch pass after final link
1164 cmd_link-vmlinux =                                                 \
1165         $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1166         $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1167
1168 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1169         +$(call if_changed_dep,link-vmlinux)
1170
1171 targets := vmlinux
1172
1173 # The actual objects are generated when descending,
1174 # make sure no implicit rule kicks in
1175 $(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1176
1177 filechk_kernel.release = \
1178         echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1179
1180 # Store (new) KERNELRELEASE string in include/config/kernel.release
1181 include/config/kernel.release: FORCE
1182         $(call filechk,kernel.release)
1183
1184 # Additional helpers built in scripts/
1185 # Carefully list dependencies so we do not try to build scripts twice
1186 # in parallel
1187 PHONY += scripts
1188 scripts: scripts_basic scripts_dtc
1189         $(Q)$(MAKE) $(build)=$(@)
1190
1191 # Things we need to do before we recursively start building the kernel
1192 # or the modules are listed in "prepare".
1193 # A multi level approach is used. prepareN is processed before prepareN-1.
1194 # archprepare is used in arch Makefiles and when processed asm symlink,
1195 # version.h and scripts_basic is processed / created.
1196
1197 PHONY += prepare archprepare
1198
1199 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1200         asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1201         include/generated/autoconf.h remove-stale-files
1202
1203 prepare0: archprepare
1204         $(Q)$(MAKE) $(build)=scripts/mod
1205         $(Q)$(MAKE) $(build)=.
1206
1207 # All the preparing..
1208 prepare: prepare0
1209
1210 PHONY += remove-stale-files
1211 remove-stale-files:
1212         $(Q)$(srctree)/scripts/remove-stale-files
1213
1214 # Support for using generic headers in asm-generic
1215 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1216
1217 PHONY += asm-generic uapi-asm-generic
1218 asm-generic: uapi-asm-generic
1219         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1220         generic=include/asm-generic
1221 uapi-asm-generic:
1222         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1223         generic=include/uapi/asm-generic
1224
1225 # Generate some files
1226 # ---------------------------------------------------------------------------
1227
1228 # KERNELRELEASE can change from a few different places, meaning version.h
1229 # needs to be updated, so this check is forced on all builds
1230
1231 uts_len := 64
1232 define filechk_utsrelease.h
1233         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1234           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1235           exit 1;                                                         \
1236         fi;                                                               \
1237         echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1238 endef
1239
1240 define filechk_version.h
1241         if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1242                 echo \#define LINUX_VERSION_CODE $(shell                 \
1243                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1244         else                                                             \
1245                 echo \#define LINUX_VERSION_CODE $(shell                 \
1246                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1247         fi;                                                              \
1248         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1249         ((c) > 255 ? 255 : (c)))';                                       \
1250         echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1251         echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1252         echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1253 endef
1254
1255 $(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1256 $(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1257 $(version_h): FORCE
1258         $(call filechk,version.h)
1259
1260 include/generated/utsrelease.h: include/config/kernel.release FORCE
1261         $(call filechk,utsrelease.h)
1262
1263 PHONY += headerdep
1264 headerdep:
1265         $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1266         $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1267
1268 # ---------------------------------------------------------------------------
1269 # Kernel headers
1270
1271 #Default location for installed headers
1272 export INSTALL_HDR_PATH = $(objtree)/usr
1273
1274 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1275       cmd_headers_install = \
1276         mkdir -p $(INSTALL_HDR_PATH); \
1277         rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1278         usr/include $(INSTALL_HDR_PATH)
1279
1280 PHONY += headers_install
1281 headers_install: headers
1282         $(call cmd,headers_install)
1283
1284 PHONY += archheaders archscripts
1285
1286 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1287
1288 PHONY += headers
1289 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1290         $(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1291         $(Q)$(MAKE) $(hdr-inst)=include/uapi
1292         $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1293
1294 ifdef CONFIG_HEADERS_INSTALL
1295 prepare: headers
1296 endif
1297
1298 PHONY += scripts_unifdef
1299 scripts_unifdef: scripts_basic
1300         $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1301
1302 # ---------------------------------------------------------------------------
1303 # Install
1304
1305 # Many distributions have the custom install script, /sbin/installkernel.
1306 # If DKMS is installed, 'make install' will eventually recurse back
1307 # to this Makefile to build and install external modules.
1308 # Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1309
1310 quiet_cmd_install = INSTALL $(INSTALL_PATH)
1311       cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1312
1313 # ---------------------------------------------------------------------------
1314 # Tools
1315
1316 ifdef CONFIG_OBJTOOL
1317 prepare: tools/objtool
1318 endif
1319
1320 ifdef CONFIG_BPF
1321 ifdef CONFIG_DEBUG_INFO_BTF
1322 prepare: tools/bpf/resolve_btfids
1323 endif
1324 endif
1325
1326 PHONY += resolve_btfids_clean
1327
1328 resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1329
1330 # tools/bpf/resolve_btfids directory might not exist
1331 # in output directory, skip its clean in that case
1332 resolve_btfids_clean:
1333 ifneq ($(wildcard $(resolve_btfids_O)),)
1334         $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1335 endif
1336
1337 # Clear a bunch of variables before executing the submake
1338 ifeq ($(quiet),silent_)
1339 tools_silent=s
1340 endif
1341
1342 tools/: FORCE
1343         $(Q)mkdir -p $(objtree)/tools
1344         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1345
1346 tools/%: FORCE
1347         $(Q)mkdir -p $(objtree)/tools
1348         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1349
1350 # ---------------------------------------------------------------------------
1351 # Kernel selftest
1352
1353 PHONY += kselftest
1354 kselftest: headers
1355         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1356
1357 kselftest-%: headers FORCE
1358         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1359
1360 PHONY += kselftest-merge
1361 kselftest-merge:
1362         $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1363         $(Q)find $(srctree)/tools/testing/selftests -name config | \
1364                 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1365         $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1366
1367 # ---------------------------------------------------------------------------
1368 # Devicetree files
1369
1370 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1371 dtstree := arch/$(SRCARCH)/boot/dts
1372 endif
1373
1374 ifneq ($(dtstree),)
1375
1376 %.dtb: dtbs_prepare
1377         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1378
1379 %.dtbo: dtbs_prepare
1380         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1381
1382 PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1383 dtbs: dtbs_prepare
1384         $(Q)$(MAKE) $(build)=$(dtstree)
1385
1386 # include/config/kernel.release is actually needed when installing DTBs because
1387 # INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1388 # dtbs_install depend on it as dtbs_install may run as root.
1389 dtbs_prepare: include/config/kernel.release scripts_dtc
1390
1391 ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1392 export CHECK_DTBS=y
1393 dtbs: dt_binding_check
1394 endif
1395
1396 dtbs_check: dtbs
1397
1398 dtbs_install:
1399         $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1400
1401 ifdef CONFIG_OF_EARLY_FLATTREE
1402 all: dtbs
1403 endif
1404
1405 endif
1406
1407 PHONY += scripts_dtc
1408 scripts_dtc: scripts_basic
1409         $(Q)$(MAKE) $(build)=scripts/dtc
1410
1411 ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1412 export CHECK_DT_BINDING=y
1413 endif
1414
1415 PHONY += dt_binding_check
1416 dt_binding_check: scripts_dtc
1417         $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1418
1419 # ---------------------------------------------------------------------------
1420 # Modules
1421
1422 ifdef CONFIG_MODULES
1423
1424 # By default, build modules as well
1425
1426 all: modules
1427
1428 # When we're building modules with modversions, we need to consider
1429 # the built-in objects during the descend as well, in order to
1430 # make sure the checksums are up to date before we record them.
1431 ifdef CONFIG_MODVERSIONS
1432   KBUILD_BUILTIN := 1
1433 endif
1434
1435 # Build modules
1436 #
1437 # A module can be listed more than once in obj-m resulting in
1438 # duplicate lines in modules.order files.  Those are removed
1439 # using awk while concatenating to the final file.
1440
1441 PHONY += modules
1442 modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1443
1444 cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1445
1446 modules.order: $(subdir-modorder) FORCE
1447         $(call if_changed,modules_order)
1448
1449 targets += modules.order
1450
1451 # Target to prepare building external modules
1452 PHONY += modules_prepare
1453 modules_prepare: prepare
1454         $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1455
1456 export modules_sign_only :=
1457
1458 ifeq ($(CONFIG_MODULE_SIG),y)
1459 PHONY += modules_sign
1460 modules_sign: modules_install
1461         @:
1462
1463 # modules_sign is a subset of modules_install.
1464 # 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1465 ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1466 modules_sign_only := y
1467 endif
1468 endif
1469
1470 modinst_pre :=
1471 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1472 modinst_pre := __modinst_pre
1473 endif
1474
1475 modules_install: $(modinst_pre)
1476 PHONY += __modinst_pre
1477 __modinst_pre:
1478         @rm -rf $(MODLIB)/kernel
1479         @rm -f $(MODLIB)/source
1480         @mkdir -p $(MODLIB)/kernel
1481         @ln -s $(abspath $(srctree)) $(MODLIB)/source
1482         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1483                 rm -f $(MODLIB)/build ; \
1484                 ln -s $(CURDIR) $(MODLIB)/build ; \
1485         fi
1486         @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1487         @cp -f modules.builtin $(MODLIB)/
1488         @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1489
1490 endif # CONFIG_MODULES
1491
1492 ###
1493 # Cleaning is done on three levels.
1494 # make clean     Delete most generated files
1495 #                Leave enough to build external modules
1496 # make mrproper  Delete the current configuration, and all generated files
1497 # make distclean Remove editor backup files, patch leftover files and the like
1498
1499 # Directories & files removed with 'make clean'
1500 CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1501                modules.builtin modules.builtin.modinfo modules.nsdeps \
1502                compile_commands.json .thinlto-cache
1503
1504 # Directories & files removed with 'make mrproper'
1505 MRPROPER_FILES += include/config include/generated          \
1506                   arch/$(SRCARCH)/include/generated .objdiff \
1507                   debian snap tar-install \
1508                   .config .config.old .version \
1509                   Module.symvers \
1510                   certs/signing_key.pem \
1511                   certs/x509.genkey \
1512                   vmlinux-gdb.py \
1513                   *.spec
1514
1515 # clean - Delete most, but leave enough to build external modules
1516 #
1517 clean: rm-files := $(CLEAN_FILES)
1518
1519 PHONY += archclean vmlinuxclean
1520
1521 vmlinuxclean:
1522         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1523         $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1524
1525 clean: archclean vmlinuxclean resolve_btfids_clean
1526
1527 # mrproper - Delete all generated files, including .config
1528 #
1529 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1530 mrproper-dirs      := $(addprefix _mrproper_,scripts)
1531
1532 PHONY += $(mrproper-dirs) mrproper
1533 $(mrproper-dirs):
1534         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1535
1536 mrproper: clean $(mrproper-dirs)
1537         $(call cmd,rmfiles)
1538
1539 # distclean
1540 #
1541 PHONY += distclean
1542
1543 distclean: mrproper
1544         @find . $(RCS_FIND_IGNORE) \
1545                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1546                 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1547                 -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1548                 -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1549                 -type f -print | xargs rm -f
1550
1551
1552 # Packaging of the kernel to various formats
1553 # ---------------------------------------------------------------------------
1554
1555 %src-pkg: FORCE
1556         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1557 %pkg: include/config/kernel.release FORCE
1558         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1559
1560 # Brief documentation of the typical targets used
1561 # ---------------------------------------------------------------------------
1562
1563 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1564 boards := $(sort $(notdir $(boards)))
1565 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1566 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1567
1568 PHONY += help
1569 help:
1570         @echo  'Cleaning targets:'
1571         @echo  '  clean           - Remove most generated files but keep the config and'
1572         @echo  '                    enough build support to build external modules'
1573         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1574         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1575         @echo  ''
1576         @echo  'Configuration targets:'
1577         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1578         @echo  ''
1579         @echo  'Other generic targets:'
1580         @echo  '  all             - Build all targets marked with [*]'
1581         @echo  '* vmlinux         - Build the bare kernel'
1582         @echo  '* modules         - Build all modules'
1583         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1584         @echo  '  dir/            - Build all files in dir and below'
1585         @echo  '  dir/file.[ois]  - Build specified target only'
1586         @echo  '  dir/file.ll     - Build the LLVM assembly file'
1587         @echo  '                    (requires compiler support for LLVM assembly generation)'
1588         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1589         @echo  '                    (requires a recent binutils and recent build (System.map))'
1590         @echo  '  dir/file.ko     - Build module including final link'
1591         @echo  '  modules_prepare - Set up for building external modules'
1592         @echo  '  tags/TAGS       - Generate tags file for editors'
1593         @echo  '  cscope          - Generate cscope index'
1594         @echo  '  gtags           - Generate GNU GLOBAL index'
1595         @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1596         @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1597         @echo  '  image_name      - Output the image name (use with make -s)'
1598         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1599          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1600          echo  ''
1601         @echo  'Static analysers:'
1602         @echo  '  checkstack      - Generate a list of stack hogs'
1603         @echo  '  versioncheck    - Sanity check on version.h usage'
1604         @echo  '  includecheck    - Check for duplicate included header files'
1605         @echo  '  export_report   - List the usages of all exported symbols'
1606         @echo  '  headerdep       - Detect inclusion cycles in headers'
1607         @echo  '  coccicheck      - Check with Coccinelle'
1608         @echo  '  clang-analyzer  - Check with clang static analyzer'
1609         @echo  '  clang-tidy      - Check with clang-tidy'
1610         @echo  ''
1611         @echo  'Tools:'
1612         @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1613         @echo  ''
1614         @echo  'Kernel selftest:'
1615         @echo  '  kselftest         - Build and run kernel selftest'
1616         @echo  '                      Build, install, and boot kernel before'
1617         @echo  '                      running kselftest on it'
1618         @echo  '                      Run as root for full coverage'
1619         @echo  '  kselftest-all     - Build kernel selftest'
1620         @echo  '  kselftest-install - Build and install kernel selftest'
1621         @echo  '  kselftest-clean   - Remove all generated kselftest files'
1622         @echo  '  kselftest-merge   - Merge all the config dependencies of'
1623         @echo  '                      kselftest to existing .config.'
1624         @echo  ''
1625         @$(if $(dtstree), \
1626                 echo 'Devicetree:'; \
1627                 echo '* dtbs             - Build device tree blobs for enabled boards'; \
1628                 echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1629                 echo '  dt_binding_check - Validate device tree binding documents'; \
1630                 echo '  dtbs_check       - Validate device tree source files';\
1631                 echo '')
1632
1633         @echo 'Userspace tools targets:'
1634         @echo '  use "make tools/help"'
1635         @echo '  or  "cd tools; make help"'
1636         @echo  ''
1637         @echo  'Kernel packaging:'
1638         @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1639         @echo  ''
1640         @echo  'Documentation targets:'
1641         @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1642         @echo  ''
1643         @echo  'Architecture specific targets ($(SRCARCH)):'
1644         @$(or $(archhelp),\
1645                 echo '  No architecture specific help defined for $(SRCARCH)')
1646         @echo  ''
1647         @$(if $(boards), \
1648                 $(foreach b, $(boards), \
1649                 printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1650                 echo '')
1651         @$(if $(board-dirs), \
1652                 $(foreach b, $(board-dirs), \
1653                 printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1654                 printf "  %-16s - Show all of the above\\n" help-boards; \
1655                 echo '')
1656
1657         @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1658         @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1659         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1660         @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1661         @echo  '                       (sparse by default)'
1662         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1663         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1664         @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1665         @echo  '                1: warnings which may be relevant and do not occur too often'
1666         @echo  '                2: warnings which occur quite often but may still be relevant'
1667         @echo  '                3: more obscure warnings, can most likely be ignored'
1668         @echo  '                e: warnings are being treated as errors'
1669         @echo  '                Multiple levels can be combined with W=12 or W=123'
1670         @echo  ''
1671         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1672         @echo  'For further info see the ./README file'
1673
1674
1675 help-board-dirs := $(addprefix help-,$(board-dirs))
1676
1677 help-boards: $(help-board-dirs)
1678
1679 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1680
1681 $(help-board-dirs): help-%:
1682         @echo  'Architecture specific targets ($(SRCARCH) $*):'
1683         @$(if $(boards-per-dir), \
1684                 $(foreach b, $(boards-per-dir), \
1685                 printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1686                 echo '')
1687
1688
1689 # Documentation targets
1690 # ---------------------------------------------------------------------------
1691 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1692                linkcheckdocs dochelp refcheckdocs
1693 PHONY += $(DOC_TARGETS)
1694 $(DOC_TARGETS):
1695         $(Q)$(MAKE) $(build)=Documentation $@
1696
1697 # Misc
1698 # ---------------------------------------------------------------------------
1699
1700 PHONY += scripts_gdb
1701 scripts_gdb: prepare0
1702         $(Q)$(MAKE) $(build)=scripts/gdb
1703         $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1704
1705 ifdef CONFIG_GDB_SCRIPTS
1706 all: scripts_gdb
1707 endif
1708
1709 else # KBUILD_EXTMOD
1710
1711 ###
1712 # External module support.
1713 # When building external modules the kernel used as basis is considered
1714 # read-only, and no consistency checks are made and the make
1715 # system is not used on the basis kernel. If updates are required
1716 # in the basis kernel ordinary make commands (without M=...) must be used.
1717
1718 # We are always building only modules.
1719 KBUILD_BUILTIN :=
1720 KBUILD_MODULES := 1
1721
1722 build-dirs := $(KBUILD_EXTMOD)
1723 $(MODORDER): descend
1724         @:
1725
1726 compile_commands.json: $(extmod_prefix)compile_commands.json
1727 PHONY += compile_commands.json
1728
1729 clean-dirs := $(KBUILD_EXTMOD)
1730 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1731         $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1732
1733 PHONY += prepare
1734 # now expand this into a simple variable to reduce the cost of shell evaluations
1735 prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1736 prepare:
1737         @if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1738                 echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1739                 echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1740                 echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1741         fi
1742
1743 PHONY += help
1744 help:
1745         @echo  '  Building external modules.'
1746         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1747         @echo  ''
1748         @echo  '  modules         - default target, build the module(s)'
1749         @echo  '  modules_install - install the module'
1750         @echo  '  clean           - remove generated files in module directory only'
1751         @echo  ''
1752
1753 # no-op for external module builds
1754 PHONY += modules_prepare
1755
1756 endif # KBUILD_EXTMOD
1757
1758 # ---------------------------------------------------------------------------
1759 # Modules
1760
1761 PHONY += modules modules_install
1762
1763 ifdef CONFIG_MODULES
1764
1765 modules: modules_check
1766         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1767
1768 PHONY += modules_check
1769 modules_check: $(MODORDER)
1770         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1771
1772 quiet_cmd_depmod = DEPMOD  $(MODLIB)
1773       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1774                    $(KERNELRELEASE)
1775
1776 modules_install:
1777         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1778         $(call cmd,depmod)
1779
1780 else # CONFIG_MODULES
1781
1782 # Modules not configured
1783 # ---------------------------------------------------------------------------
1784
1785 modules modules_install:
1786         @echo >&2 '***'
1787         @echo >&2 '*** The present kernel configuration has modules disabled.'
1788         @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1789         @echo >&2 '*** to enable CONFIG_MODULES.'
1790         @echo >&2 '***'
1791         @exit 1
1792
1793 endif # CONFIG_MODULES
1794
1795 # Single targets
1796 # ---------------------------------------------------------------------------
1797 # To build individual files in subdirectories, you can do like this:
1798 #
1799 #   make foo/bar/baz.s
1800 #
1801 # The supported suffixes for single-target are listed in 'single-targets'
1802 #
1803 # To build only under specific subdirectories, you can do like this:
1804 #
1805 #   make foo/bar/baz/
1806
1807 ifdef single-build
1808
1809 # .ko is special because modpost is needed
1810 single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1811 single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1812                 $(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1813
1814 $(single-ko): single_modpost
1815         @:
1816 $(single-no-ko): descend
1817         @:
1818
1819 ifeq ($(KBUILD_EXTMOD),)
1820 # For the single build of in-tree modules, use a temporary file to avoid
1821 # the situation of modules_install installing an invalid modules.order.
1822 MODORDER := .modules.tmp
1823 endif
1824
1825 PHONY += single_modpost
1826 single_modpost: $(single-no-ko) modules_prepare
1827         $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1828         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1829
1830 KBUILD_MODULES := 1
1831
1832 export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1833
1834 # trim unrelated directories
1835 build-dirs := $(foreach d, $(build-dirs), \
1836                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1837
1838 endif
1839
1840 ifndef CONFIG_MODULES
1841 KBUILD_MODULES :=
1842 endif
1843
1844 # Handle descending into subdirectories listed in $(build-dirs)
1845 # Preset locale variables to speed up the build process. Limit locale
1846 # tweaks to this spot to avoid wrong language settings when running
1847 # make menuconfig etc.
1848 # Error messages still appears in the original language
1849 PHONY += descend $(build-dirs)
1850 descend: $(build-dirs)
1851 $(build-dirs): prepare
1852         $(Q)$(MAKE) $(build)=$@ \
1853         single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1854         need-builtin=1 need-modorder=1
1855
1856 clean-dirs := $(addprefix _clean_, $(clean-dirs))
1857 PHONY += $(clean-dirs) clean
1858 $(clean-dirs):
1859         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1860
1861 clean: $(clean-dirs)
1862         $(call cmd,rmfiles)
1863         @find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1864                 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1865                 -o -name '*.ko.*' \
1866                 -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1867                 -o -name '*.dwo' -o -name '*.lst' \
1868                 -o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
1869                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1870                 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1871                 -o -name '*.asn1.[ch]' \
1872                 -o -name '*.symtypes' -o -name 'modules.order' \
1873                 -o -name '.tmp_*' \
1874                 -o -name '*.c.[012]*.*' \
1875                 -o -name '*.ll' \
1876                 -o -name '*.gcno' \
1877                 -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1878
1879 # Generate tags for editors
1880 # ---------------------------------------------------------------------------
1881 quiet_cmd_tags = GEN     $@
1882       cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1883
1884 tags TAGS cscope gtags: FORCE
1885         $(call cmd,tags)
1886
1887 # Script to generate missing namespace dependencies
1888 # ---------------------------------------------------------------------------
1889
1890 PHONY += nsdeps
1891 nsdeps: export KBUILD_NSDEPS=1
1892 nsdeps: modules
1893         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1894
1895 # Clang Tooling
1896 # ---------------------------------------------------------------------------
1897
1898 quiet_cmd_gen_compile_commands = GEN     $@
1899       cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1900
1901 $(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1902         $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1903         $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1904         $(call if_changed,gen_compile_commands)
1905
1906 targets += $(extmod_prefix)compile_commands.json
1907
1908 PHONY += clang-tidy clang-analyzer
1909
1910 ifdef CONFIG_CC_IS_CLANG
1911 quiet_cmd_clang_tools = CHECK   $<
1912       cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1913
1914 clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1915         $(call cmd,clang_tools)
1916 else
1917 clang-tidy clang-analyzer:
1918         @echo "$@ requires CC=clang" >&2
1919         @false
1920 endif
1921
1922 # Scripts to check various things for consistency
1923 # ---------------------------------------------------------------------------
1924
1925 PHONY += includecheck versioncheck coccicheck export_report
1926
1927 includecheck:
1928         find $(srctree)/* $(RCS_FIND_IGNORE) \
1929                 -name '*.[hcS]' -type f -print | sort \
1930                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1931
1932 versioncheck:
1933         find $(srctree)/* $(RCS_FIND_IGNORE) \
1934                 -name '*.[hcS]' -type f -print | sort \
1935                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1936
1937 coccicheck:
1938         $(Q)$(BASH) $(srctree)/scripts/$@
1939
1940 export_report:
1941         $(PERL) $(srctree)/scripts/export_report.pl
1942
1943 PHONY += checkstack kernelrelease kernelversion image_name
1944
1945 # UML needs a little special treatment here.  It wants to use the host
1946 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1947 # else wants $(ARCH), including people doing cross-builds, which means
1948 # that $(SUBARCH) doesn't work here.
1949 ifeq ($(ARCH), um)
1950 CHECKSTACK_ARCH := $(SUBARCH)
1951 else
1952 CHECKSTACK_ARCH := $(ARCH)
1953 endif
1954 checkstack:
1955         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1956         $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1957
1958 kernelrelease:
1959         @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1960
1961 kernelversion:
1962         @echo $(KERNELVERSION)
1963
1964 image_name:
1965         @echo $(KBUILD_IMAGE)
1966
1967 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1968       cmd_rmfiles = rm -rf $(rm-files)
1969
1970 # read saved command lines for existing targets
1971 existing-targets := $(wildcard $(sort $(targets)))
1972
1973 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1974
1975 endif # config-build
1976 endif # mixed-build
1977 endif # need-sub-make
1978
1979 PHONY += FORCE
1980 FORCE:
1981
1982 # Declare the contents of the PHONY variable as phony.  We keep that
1983 # information in a variable so we can use it in if_changed and friends.
1984 .PHONY: $(PHONY)