Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 VERSION = 5
   3 PATCHLEVEL = 15
   4 SUBLEVEL = 35
   5 EXTRAVERSION =
   6 NAME = Trick or Treat
   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         $(error building multiple external modules is not supported))
 131
 132 # Remove trailing slashes
 133 ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
 134 KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
 135 endif
 136
 137 export KBUILD_EXTMOD
 138
 139 # Kbuild will save output files in the current working directory.
 140 # This does not need to match to the root of the kernel source tree.
 141 #
 142 # For example, you can do this:
 143 #
 144 #  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
 145 #
 146 # If you want to save output files in a different location, there are
 147 # two syntaxes to specify it.
 148 #
 149 # 1) O=
 150 # Use "make O=dir/to/store/output/files/"
 151 #
 152 # 2) Set KBUILD_OUTPUT
 153 # Set the environment variable KBUILD_OUTPUT to point to the output directory.
 154 # export KBUILD_OUTPUT=dir/to/store/output/files/; make
 155 #
 156 # The O= assignment takes precedence over the KBUILD_OUTPUT environment
 157 # variable.
 158
 159 # Do we want to change the working directory?
 160 ifeq ("$(origin O)", "command line")
 161   KBUILD_OUTPUT := $(O)
 162 endif
 163
 164 ifneq ($(KBUILD_OUTPUT),)
 165 # Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
 166 # expand a shell special character '~'. We use a somewhat tedious way here.
 167 abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
 168 $(if $(abs_objtree),, \
 169      $(error failed to create output directory "$(KBUILD_OUTPUT)"))
 170
 171 # $(realpath ...) resolves symlinks
 172 abs_objtree := $(realpath $(abs_objtree))
 173 else
 174 abs_objtree := $(CURDIR)
 175 endif # ifneq ($(KBUILD_OUTPUT),)
 176
 177 ifeq ($(abs_objtree),$(CURDIR))
 178 # Suppress "Entering directory ..." unless we are changing the work directory.
 179 MAKEFLAGS += --no-print-directory
 180 else
 181 need-sub-make := 1
 182 endif
 183
 184 this-makefile := $(lastword $(MAKEFILE_LIST))
 185 abs_srctree := $(realpath $(dir $(this-makefile)))
 186
 187 ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
 188 $(error source directory cannot contain spaces or colons)
 189 endif
 190
 191 ifneq ($(abs_srctree),$(abs_objtree))
 192 # Look for make include files relative to root of kernel src
 193 #
 194 # --included-dir is added for backward compatibility, but you should not rely on
 195 # it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
 196 MAKEFLAGS += --include-dir=$(abs_srctree)
 197 endif
 198
 199 ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 200 # 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
 201 # We need to invoke sub-make to avoid implicit rules in the top Makefile.
 202 need-sub-make := 1
 203 # Cancel implicit rules for this Makefile.
 204 $(this-makefile): ;
 205 endif
 206
 207 export abs_srctree abs_objtree
 208 export sub_make_done := 1
 209
 210 ifeq ($(need-sub-make),1)
 211
 212 PHONY += $(MAKECMDGOALS) __sub-make
 213
 214 $(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 215         @:
 216
 217 # Invoke a second make in the output directory, passing relevant variables
 218 __sub-make:
 219         $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 220
 221 endif # need-sub-make
 222 endif # sub_make_done
 223
 224 # We process the rest of the Makefile if this is the final invocation of make
 225 ifeq ($(need-sub-make),)
 226
 227 # Do not print "Entering directory ...",
 228 # but we want to display it when entering to the output directory
 229 # so that IDEs/editors are able to understand relative filenames.
 230 MAKEFLAGS += --no-print-directory
 231
 232 ifeq ($(abs_srctree),$(abs_objtree))
 233         # building in the source tree
 234         srctree := .
 235         building_out_of_srctree :=
 236 else
 237         ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
 238                 # building in a subdirectory of the source tree
 239                 srctree := ..
 240         else
 241                 srctree := $(abs_srctree)
 242         endif
 243         building_out_of_srctree := 1
 244 endif
 245
 246 ifneq ($(KBUILD_ABS_SRCTREE),)
 247 srctree := $(abs_srctree)
 248 endif
 249
 250 objtree         := .
 251 VPATH           := $(srctree)
 252
 253 export building_out_of_srctree srctree objtree VPATH
 254
 255 # To make sure we do not include .config for any of the *config targets
 256 # catch them early, and hand them over to scripts/kconfig/Makefile
 257 # It is allowed to specify more targets when calling make, including
 258 # mixing *config targets and build targets.
 259 # For example 'make oldconfig all'.
 260 # Detect when mixed targets is specified, and make a second invocation
 261 # of make so .config is not included in this case either (for *config).
 262
 263 version_h := include/generated/uapi/linux/version.h
 264
 265 clean-targets := %clean mrproper cleandocs
 266 no-dot-config-targets := $(clean-targets) \
 267                          cscope gtags TAGS tags help% %docs check% coccicheck \
 268                          $(version_h) headers headers_% archheaders archscripts \
 269                          %asm-generic kernelversion %src-pkg dt_binding_check \
 270                          outputmakefile
 271 # Installation targets should not require compiler. Unfortunately, vdso_install
 272 # is an exception where build artifacts may be updated. This must be fixed.
 273 no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
 274                         headers_install modules_install kernelrelease image_name
 275 no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
 276                           image_name
 277 single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
 278
 279 config-build    :=
 280 mixed-build     :=
 281 need-config     := 1
 282 need-compiler   := 1
 283 may-sync-config := 1
 284 single-build    :=
 285
 286 ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 287         ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 288                 need-config :=
 289         endif
 290 endif
 291
 292 ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
 293         ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
 294                 need-compiler :=
 295         endif
 296 endif
 297
 298 ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 299         ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 300                 may-sync-config :=
 301         endif
 302 endif
 303
 304 ifneq ($(KBUILD_EXTMOD),)
 305         may-sync-config :=
 306 endif
 307
 308 ifeq ($(KBUILD_EXTMOD),)
 309         ifneq ($(filter %config,$(MAKECMDGOALS)),)
 310                 config-build := 1
 311                 ifneq ($(words $(MAKECMDGOALS)),1)
 312                         mixed-build := 1
 313                 endif
 314         endif
 315 endif
 316
 317 # We cannot build single targets and the others at the same time
 318 ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 319         single-build := 1
 320         ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 321                 mixed-build := 1
 322         endif
 323 endif
 324
 325 # For "make -j clean all", "make -j mrproper defconfig all", etc.
 326 ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 327         ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 328                 mixed-build := 1
 329         endif
 330 endif
 331
 332 # install and modules_install need also be processed one by one
 333 ifneq ($(filter install,$(MAKECMDGOALS)),)
 334         ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 335                 mixed-build := 1
 336         endif
 337 endif
 338
 339 ifdef mixed-build
 340 # ===========================================================================
 341 # We're called with mixed targets (*config and build targets).
 342 # Handle them one by one.
 343
 344 PHONY += $(MAKECMDGOALS) __build_one_by_one
 345
 346 $(MAKECMDGOALS): __build_one_by_one
 347         @:
 348
 349 __build_one_by_one:
 350         $(Q)set -e; \
 351         for i in $(MAKECMDGOALS); do \
 352                 $(MAKE) -f $(srctree)/Makefile $$i; \
 353         done
 354
 355 else # !mixed-build
 356
 357 include $(srctree)/scripts/Kbuild.include
 358
 359 # Read KERNELRELEASE from include/config/kernel.release (if it exists)
 360 KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 361 KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 362 export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 363
 364 include $(srctree)/scripts/subarch.include
 365
 366 # Cross compiling and selecting different set of gcc/bin-utils
 367 # ---------------------------------------------------------------------------
 368 #
 369 # When performing cross compilation for other architectures ARCH shall be set
 370 # to the target architecture. (See arch/* for the possibilities).
 371 # ARCH can be set during invocation of make:
 372 # make ARCH=ia64
 373 # Another way is to have ARCH set in the environment.
 374 # The default ARCH is the host where make is executed.
 375
 376 # CROSS_COMPILE specify the prefix used for all executables used
 377 # during compilation. Only gcc and related bin-utils executables
 378 # are prefixed with $(CROSS_COMPILE).
 379 # CROSS_COMPILE can be set on the command line
 380 # make CROSS_COMPILE=ia64-linux-
 381 # Alternatively CROSS_COMPILE can be set in the environment.
 382 # Default value for CROSS_COMPILE is not to prefix executables
 383 # Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 384 ARCH            ?= $(SUBARCH)
 385
 386 # Architecture as present in compile.h
 387 UTS_MACHINE     := $(ARCH)
 388 SRCARCH         := $(ARCH)
 389
 390 # Additional ARCH settings for x86
 391 ifeq ($(ARCH),i386)
 392         SRCARCH := x86
 393 endif
 394 ifeq ($(ARCH),x86_64)
 395         SRCARCH := x86
 396 endif
 397
 398 # Additional ARCH settings for sparc
 399 ifeq ($(ARCH),sparc32)
 400        SRCARCH := sparc
 401 endif
 402 ifeq ($(ARCH),sparc64)
 403        SRCARCH := sparc
 404 endif
 405
 406 # Additional ARCH settings for parisc
 407 ifeq ($(ARCH),parisc64)
 408        SRCARCH := parisc
 409 endif
 410
 411 export cross_compiling :=
 412 ifneq ($(SRCARCH),$(SUBARCH))
 413 cross_compiling := 1
 414 endif
 415
 416 KCONFIG_CONFIG  ?= .config
 417 export KCONFIG_CONFIG
 418
 419 # SHELL used by kbuild
 420 CONFIG_SHELL := sh
 421
 422 HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 423 HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 424 HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 425
 426 ifneq ($(LLVM),)
 427 HOSTCC  = clang
 428 HOSTCXX = clang++
 429 else
 430 HOSTCC  = gcc
 431 HOSTCXX = g++
 432 endif
 433
 434 export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 435                               -O2 -fomit-frame-pointer -std=gnu89
 436 export KBUILD_USERLDFLAGS :=
 437
 438 KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 439 KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 440 KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 441 KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 442
 443 # Make variables (CC, etc...)
 444 CPP             = $(CC) -E
 445 ifneq ($(LLVM),)
 446 CC              = clang
 447 LD              = ld.lld
 448 AR              = llvm-ar
 449 NM              = llvm-nm
 450 OBJCOPY         = llvm-objcopy
 451 OBJDUMP         = llvm-objdump
 452 READELF         = llvm-readelf
 453 STRIP           = llvm-strip
 454 else
 455 CC              = $(CROSS_COMPILE)gcc
 456 LD              = $(CROSS_COMPILE)ld
 457 AR              = $(CROSS_COMPILE)ar
 458 NM              = $(CROSS_COMPILE)nm
 459 OBJCOPY         = $(CROSS_COMPILE)objcopy
 460 OBJDUMP         = $(CROSS_COMPILE)objdump
 461 READELF         = $(CROSS_COMPILE)readelf
 462 STRIP           = $(CROSS_COMPILE)strip
 463 endif
 464 PAHOLE          = pahole
 465 RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 466 LEX             = flex
 467 YACC            = bison
 468 AWK             = awk
 469 INSTALLKERNEL  := installkernel
 470 DEPMOD          = depmod
 471 PERL            = perl
 472 PYTHON3         = python3
 473 CHECK           = sparse
 474 BASH            = bash
 475 KGZIP           = gzip
 476 KBZIP2          = bzip2
 477 KLZOP           = lzop
 478 LZMA            = lzma
 479 LZ4             = lz4c
 480 XZ              = xz
 481 ZSTD            = zstd
 482
 483 PAHOLE_FLAGS    = $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
 484
 485 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 486                   -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 487 NOSTDINC_FLAGS :=
 488 CFLAGS_MODULE   =
 489 AFLAGS_MODULE   =
 490 LDFLAGS_MODULE  =
 491 CFLAGS_KERNEL   =
 492 AFLAGS_KERNEL   =
 493 LDFLAGS_vmlinux =
 494
 495 # Use USERINCLUDE when you must reference the UAPI directories only.
 496 USERINCLUDE    := \
 497                 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 498                 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 499                 -I$(srctree)/include/uapi \
 500                 -I$(objtree)/include/generated/uapi \
 501                 -include $(srctree)/include/linux/compiler-version.h \
 502                 -include $(srctree)/include/linux/kconfig.h
 503
 504 # Use LINUXINCLUDE when you must reference the include/ directory.
 505 # Needed to be compatible with the O= option
 506 LINUXINCLUDE    := \
 507                 -I$(srctree)/arch/$(SRCARCH)/include \
 508                 -I$(objtree)/arch/$(SRCARCH)/include/generated \
 509                 $(if $(building_out_of_srctree),-I$(srctree)/include) \
 510                 -I$(objtree)/include \
 511                 $(USERINCLUDE)
 512
 513 # UBUNTU: Include our third party driver stuff too
 514 LINUXINCLUDE   += -I$(srctree)/ubuntu/include
 515
 516 KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 517 KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 518                    -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 519                    -Werror=implicit-function-declaration -Werror=implicit-int \
 520                    -Werror=return-type -Wno-format-security \
 521                    -std=gnu89
 522 KBUILD_CPPFLAGS := -D__KERNEL__
 523 KBUILD_AFLAGS_KERNEL :=
 524 KBUILD_CFLAGS_KERNEL :=
 525 KBUILD_AFLAGS_MODULE  := -DMODULE
 526 KBUILD_CFLAGS_MODULE  := -DMODULE
 527 KBUILD_LDFLAGS_MODULE :=
 528 KBUILD_LDFLAGS :=
 529 CLANG_FLAGS :=
 530
 531 export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
 532 export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 533 export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 534 export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 535 export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 536
 537 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 538 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 539 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 540 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 541 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 542 export PAHOLE_FLAGS
 543
 544 # Files to ignore in find ... statements
 545
 546 export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 547                           -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 548                           -prune -o
 549 export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 550                          --exclude CVS --exclude .pc --exclude .hg --exclude .git
 551
 552 # ===========================================================================
 553 # Rules shared between *config targets and build targets
 554
 555 # Basic helpers built in scripts/basic/
 556 PHONY += scripts_basic
 557 scripts_basic:
 558         $(Q)$(MAKE) $(build)=scripts/basic
 559
 560 PHONY += outputmakefile
 561 ifdef building_out_of_srctree
 562 # Before starting out-of-tree build, make sure the source tree is clean.
 563 # outputmakefile generates a Makefile in the output directory, if using a
 564 # separate output directory. This allows convenient use of make in the
 565 # output directory.
 566 # At the same time when output Makefile generated, generate .gitignore to
 567 # ignore whole output directory
 568
 569 quiet_cmd_makefile = GEN     Makefile
 570       cmd_makefile = { \
 571         echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
 572         echo "include $(srctree)/Makefile"; \
 573         } > Makefile
 574
 575 outputmakefile:
 576         $(Q)if [ -f $(srctree)/.config -o \
 577                  -d $(srctree)/include/config -o \
 578                  -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 579                 echo >&2 "***"; \
 580                 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 581                 echo >&2 "*** in $(abs_srctree)";\
 582                 echo >&2 "***"; \
 583                 false; \
 584         fi
 585         $(Q)ln -fsn $(srctree) source
 586         $(call cmd,makefile)
 587         $(Q)test -e .gitignore || \
 588         { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 589 endif
 590
 591 # The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 592 # Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 593 # CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 594 # and from include/config/auto.conf.cmd to detect the compiler upgrade.
 595 CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
 596
 597 ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 598 include $(srctree)/scripts/Makefile.clang
 599 endif
 600
 601 # Include this also for config targets because some architectures need
 602 # cc-cross-prefix to determine CROSS_COMPILE.
 603 ifdef need-compiler
 604 include $(srctree)/scripts/Makefile.compiler
 605 endif
 606
 607 ifdef config-build
 608 # ===========================================================================
 609 # *config targets only - make sure prerequisites are updated, and descend
 610 # in scripts/kconfig to make the *config target
 611
 612 # Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 613 # KBUILD_DEFCONFIG may point out an alternative default configuration
 614 # used for 'make defconfig'
 615 include $(srctree)/arch/$(SRCARCH)/Makefile
 616 export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 617
 618 config: outputmakefile scripts_basic FORCE
 619         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 620
 621 %config: outputmakefile scripts_basic FORCE
 622         $(Q)$(MAKE) $(build)=scripts/kconfig $@
 623
 624 else #!config-build
 625 # ===========================================================================
 626 # Build targets only - this includes vmlinux, arch specific targets, clean
 627 # targets and others. In general all targets except *config targets.
 628
 629 # If building an external module we do not care about the all: rule
 630 # but instead __all depend on modules
 631 PHONY += all
 632 ifeq ($(KBUILD_EXTMOD),)
 633 __all: all
 634 else
 635 __all: modules
 636 endif
 637
 638 # Decide whether to build built-in, modular, or both.
 639 # Normally, just do built-in.
 640
 641 KBUILD_MODULES :=
 642 KBUILD_BUILTIN := 1
 643
 644 # If we have only "make modules", don't compile built-in objects.
 645 ifeq ($(MAKECMDGOALS),modules)
 646   KBUILD_BUILTIN :=
 647 endif
 648
 649 # If we have "make <whatever> modules", compile modules
 650 # in addition to whatever we do anyway.
 651 # Just "make" or "make all" shall build modules as well
 652
 653 ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 654   KBUILD_MODULES := 1
 655 endif
 656
 657 ifeq ($(MAKECMDGOALS),)
 658   KBUILD_MODULES := 1
 659 endif
 660
 661 export KBUILD_MODULES KBUILD_BUILTIN
 662
 663 ifdef need-config
 664 include include/config/auto.conf
 665 endif
 666
 667 ifeq ($(KBUILD_EXTMOD),)
 668 # Objects we will link into vmlinux / subdirs we need to visit
 669 core-y          := init/ usr/ arch/$(SRCARCH)/
 670 drivers-y       := drivers/ sound/ ubuntu/
 671 drivers-$(CONFIG_SAMPLES) += samples/
 672 drivers-$(CONFIG_NET) += net/
 673 drivers-y       += virt/
 674 libs-y          := lib/
 675 endif # KBUILD_EXTMOD
 676
 677 # The all: target is the default when no target is given on the
 678 # command line.
 679 # This allow a user to issue only 'make' to build a kernel including modules
 680 # Defaults to vmlinux, but the arch makefile usually adds further targets
 681 all: vmlinux
 682
 683 CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage
 684 ifdef CONFIG_CC_IS_GCC
 685 CFLAGS_GCOV     += -fno-tree-loop-im
 686 endif
 687 export CFLAGS_GCOV
 688
 689 # The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 690 ifdef CONFIG_FUNCTION_TRACER
 691   CC_FLAGS_FTRACE := -pg
 692 endif
 693
 694 ifdef CONFIG_CC_IS_GCC
 695 RETPOLINE_CFLAGS        := $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
 696 RETPOLINE_VDSO_CFLAGS   := $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
 697 endif
 698 ifdef CONFIG_CC_IS_CLANG
 699 RETPOLINE_CFLAGS        := -mretpoline-external-thunk
 700 RETPOLINE_VDSO_CFLAGS   := -mretpoline
 701 endif
 702 export RETPOLINE_CFLAGS
 703 export RETPOLINE_VDSO_CFLAGS
 704
 705 include $(srctree)/arch/$(SRCARCH)/Makefile
 706
 707 ifdef need-config
 708 ifdef may-sync-config
 709 # Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 710 # changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 711 # because some architectures define CROSS_COMPILE there.
 712 include include/config/auto.conf.cmd
 713
 714 $(KCONFIG_CONFIG):
 715         @echo >&2 '***'
 716         @echo >&2 '*** Configuration file "$@" not found!'
 717         @echo >&2 '***'
 718         @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 719         @echo >&2 '*** "make menuconfig" or "make xconfig").'
 720         @echo >&2 '***'
 721         @/bin/false
 722
 723 # The actual configuration files used during the build are stored in
 724 # include/generated/ and include/config/. Update them if .config is newer than
 725 # include/config/auto.conf (which mirrors .config).
 726 #
 727 # This exploits the 'multi-target pattern rule' trick.
 728 # The syncconfig should be executed only once to make all the targets.
 729 # (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 730 #
 731 # Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
 732 # so you cannot notice that Kconfig is waiting for the user input.
 733 %/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 734         $(Q)$(kecho) "  SYNC    $@"
 735         $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
 736 else # !may-sync-config
 737 # External modules and some install targets need include/generated/autoconf.h
 738 # and include/config/auto.conf but do not care if they are up-to-date.
 739 # Use auto.conf to trigger the test
 740 PHONY += include/config/auto.conf
 741
 742 include/config/auto.conf:
 743         $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 744         echo >&2;                                                       \
 745         echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 746         echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 747         echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 748         echo >&2 ;                                                      \
 749         /bin/false)
 750
 751 endif # may-sync-config
 752 endif # need-config
 753
 754 KBUILD_CFLAGS   += -fno-delete-null-pointer-checks
 755 KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 756 KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 757 KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 758 KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 759
 760 ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 761 KBUILD_CFLAGS += -O2
 762 else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
 763 KBUILD_CFLAGS += -O3
 764 else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 765 KBUILD_CFLAGS += -Os
 766 endif
 767
 768 # Tell gcc to never replace conditional load with a non-conditional one
 769 ifdef CONFIG_CC_IS_GCC
 770 # gcc-10 renamed --param=allow-store-data-races=0 to
 771 # -fno-allow-store-data-races.
 772 KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 773 KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 774 endif
 775
 776 ifdef CONFIG_READABLE_ASM
 777 # Disable optimizations that make assembler listings hard to read.
 778 # reorder blocks reorders the control in the function
 779 # ipa clone creates specialized cloned functions
 780 # partial inlining inlines only parts of functions
 781 KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
 782 endif
 783
 784 ifneq ($(CONFIG_FRAME_WARN),0)
 785 KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 786 endif
 787
 788 stackp-flags-y                                    := -fno-stack-protector
 789 stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 790 stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 791
 792 KBUILD_CFLAGS += $(stackp-flags-y)
 793
 794 KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
 795 KBUILD_CFLAGS += $(KBUILD_CFLAGS-y)
 796
 797 ifdef CONFIG_CC_IS_CLANG
 798 KBUILD_CPPFLAGS += -Qunused-arguments
 799 # The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable.
 800 KBUILD_CFLAGS += -Wno-gnu
 801 # CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 802 # source of a reference will be _MergedGlobals and not on of the whitelisted names.
 803 # See modpost pattern 2
 804 KBUILD_CFLAGS += -mno-global-merge
 805 else
 806
 807 # Warn about unmarked fall-throughs in switch statement.
 808 # Disabled for clang while comment to attribute conversion happens and
 809 # https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
 810 KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,)
 811 # gcc inanely warns about local variables called 'main'
 812 KBUILD_CFLAGS += -Wno-main
 813 endif
 814
 815 # These warnings generated too much noise in a regular build.
 816 # Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 817 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 818 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 819
 820 ifdef CONFIG_FRAME_POINTER
 821 KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 822 else
 823 # Some targets (ARM with Thumb2, for example), can't be built with frame
 824 # pointers.  For those, we don't have FUNCTION_TRACER automatically
 825 # select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 826 # incompatible with -fomit-frame-pointer with current GCC, so we don't use
 827 # -fomit-frame-pointer with FUNCTION_TRACER.
 828 ifndef CONFIG_FUNCTION_TRACER
 829 KBUILD_CFLAGS   += -fomit-frame-pointer
 830 endif
 831 endif
 832
 833 # Initialize all stack variables with a 0xAA pattern.
 834 ifdef CONFIG_INIT_STACK_ALL_PATTERN
 835 KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 836 endif
 837
 838 # Initialize all stack variables with a zero value.
 839 ifdef CONFIG_INIT_STACK_ALL_ZERO
 840 # Future support for zero initialization is still being debated, see
 841 # https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
 842 # renamed or dropped.
 843 KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 844 KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 845 endif
 846
 847 # While VLAs have been removed, GCC produces unreachable stack probes
 848 # for the randomize_kstack_offset feature. Disable it for all compilers.
 849 KBUILD_CFLAGS   += $(call cc-option, -fno-stack-clash-protection)
 850
 851 # Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
 852 ifdef CONFIG_ZERO_CALL_USED_REGS
 853 KBUILD_CFLAGS   += -fzero-call-used-regs=used-gpr
 854 endif
 855
 856 DEBUG_CFLAGS    :=
 857
 858 ifdef CONFIG_DEBUG_INFO
 859
 860 ifdef CONFIG_DEBUG_INFO_SPLIT
 861 DEBUG_CFLAGS    += -gsplit-dwarf
 862 else
 863 DEBUG_CFLAGS    += -g
 864 endif
 865
 866 ifndef CONFIG_AS_IS_LLVM
 867 KBUILD_AFLAGS   += -Wa,-gdwarf-2
 868 endif
 869
 870 ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
 871 dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
 872 dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
 873 DEBUG_CFLAGS    += -gdwarf-$(dwarf-version-y)
 874 endif
 875
 876 ifdef CONFIG_DEBUG_INFO_REDUCED
 877 DEBUG_CFLAGS    += -fno-var-tracking
 878 ifdef CONFIG_CC_IS_GCC
 879 DEBUG_CFLAGS    += -femit-struct-debug-baseonly
 880 endif
 881 endif
 882
 883 ifdef CONFIG_DEBUG_INFO_COMPRESSED
 884 DEBUG_CFLAGS    += -gz=zlib
 885 KBUILD_AFLAGS   += -gz=zlib
 886 KBUILD_LDFLAGS  += --compress-debug-sections=zlib
 887 endif
 888
 889 endif # CONFIG_DEBUG_INFO
 890
 891 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 892 export DEBUG_CFLAGS
 893
 894 ifdef CONFIG_FUNCTION_TRACER
 895 ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 896   CC_FLAGS_FTRACE       += -mrecord-mcount
 897   ifdef CONFIG_HAVE_NOP_MCOUNT
 898     ifeq ($(call cc-option-yn, -mnop-mcount),y)
 899       CC_FLAGS_FTRACE   += -mnop-mcount
 900       CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 901     endif
 902   endif
 903 endif
 904 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 905   CC_FLAGS_USING        += -DCC_USING_NOP_MCOUNT
 906 endif
 907 ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 908   ifdef CONFIG_HAVE_C_RECORDMCOUNT
 909     BUILD_C_RECORDMCOUNT := y
 910     export BUILD_C_RECORDMCOUNT
 911   endif
 912 endif
 913 ifdef CONFIG_HAVE_FENTRY
 914   # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
 915   ifeq ($(call cc-option-yn, -mfentry),y)
 916     CC_FLAGS_FTRACE     += -mfentry
 917     CC_FLAGS_USING      += -DCC_USING_FENTRY
 918   endif
 919 endif
 920 export CC_FLAGS_FTRACE
 921 KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 922 KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 923 endif
 924
 925 # We trigger additional mismatches with less inlining
 926 ifdef CONFIG_DEBUG_SECTION_MISMATCH
 927 KBUILD_CFLAGS += -fno-inline-functions-called-once
 928 endif
 929
 930 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 931 KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 932 LDFLAGS_vmlinux += --gc-sections
 933 endif
 934
 935 ifdef CONFIG_SHADOW_CALL_STACK
 936 CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 937 KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 938 export CC_FLAGS_SCS
 939 endif
 940
 941 ifdef CONFIG_LTO_CLANG
 942 ifdef CONFIG_LTO_CLANG_THIN
 943 CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 944 KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
 945 else
 946 CC_FLAGS_LTO    := -flto
 947 endif
 948 CC_FLAGS_LTO    += -fvisibility=hidden
 949
 950 # Limit inlining across translation units to reduce binary size
 951 KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 952
 953 # Check for frame size exceeding threshold during prolog/epilog insertion
 954 # when using lld < 13.0.0.
 955 ifneq ($(CONFIG_FRAME_WARN),0)
 956 ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
 957 KBUILD_LDFLAGS  += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 958 endif
 959 endif
 960 endif
 961
 962 ifdef CONFIG_LTO
 963 KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 964 KBUILD_AFLAGS   += -fno-lto
 965 export CC_FLAGS_LTO
 966 endif
 967
 968 ifdef CONFIG_CFI_CLANG
 969 CC_FLAGS_CFI    := -fsanitize=cfi \
 970                    -fsanitize-cfi-cross-dso \
 971                    -fno-sanitize-cfi-canonical-jump-tables \
 972                    -fno-sanitize-trap=cfi \
 973                    -fno-sanitize-blacklist
 974
 975 ifdef CONFIG_CFI_PERMISSIVE
 976 CC_FLAGS_CFI    += -fsanitize-recover=cfi
 977 endif
 978
 979 # If LTO flags are filtered out, we must also filter out CFI.
 980 CC_FLAGS_LTO    += $(CC_FLAGS_CFI)
 981 KBUILD_CFLAGS   += $(CC_FLAGS_CFI)
 982 export CC_FLAGS_CFI
 983 endif
 984
 985 ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
 986 KBUILD_CFLAGS += -falign-functions=64
 987 endif
 988
 989 # arch Makefile may override CC so keep this after arch Makefile is included
 990 NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 991
 992 # warn about C99 declaration after statement
 993 KBUILD_CFLAGS += -Wdeclaration-after-statement
 994
 995 # Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 996 KBUILD_CFLAGS += -Wvla
 997
 998 # disable pointer signed / unsigned warnings in gcc 4.0
 999 KBUILD_CFLAGS += -Wno-pointer-sign
1000
1001 # disable stringop warnings in gcc 8+
1002 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1003
1004 # We'll want to enable this eventually, but it's not going away for 5.7 at least
1005 KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
1006 KBUILD_CFLAGS += -Wno-array-bounds
1007 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1008
1009 # Another good warning that we'll want to enable eventually
1010 KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1011
1012 # Enabled with W=2, disabled by default as noisy
1013 ifdef CONFIG_CC_IS_GCC
1014 KBUILD_CFLAGS += -Wno-maybe-uninitialized
1015 endif
1016
1017 # disable invalid "can't wrap" optimizations for signed / pointers
1018 KBUILD_CFLAGS   += -fno-strict-overflow
1019
1020 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
1021 KBUILD_CFLAGS  += -fno-stack-check
1022
1023 # conserve stack if available
1024 ifdef CONFIG_CC_IS_GCC
1025 KBUILD_CFLAGS   += -fconserve-stack
1026 endif
1027
1028 # Prohibit date/time macros, which would make the build non-deterministic
1029 KBUILD_CFLAGS   += -Werror=date-time
1030
1031 # enforce correct pointer usage
1032 KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1033
1034 # Require designated initializers for all marked structures
1035 KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1036
1037 # change __FILE__ to the relative path from the srctree
1038 KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1039
1040 # include additional Makefiles when needed
1041 include-y                       := scripts/Makefile.extrawarn
1042 include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
1043 include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
1044 include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
1045 include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
1046 include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
1047
1048 include $(addprefix $(srctree)/, $(include-y))
1049
1050 # scripts/Makefile.gcc-plugins is intentionally included last.
1051 # Do not add $(call cc-option,...) below this line. When you build the kernel
1052 # from the clean source tree, the GCC plugins do not exist at this point.
1053
1054 # Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1055 KBUILD_CPPFLAGS += $(KCPPFLAGS)
1056 KBUILD_AFLAGS   += $(KAFLAGS)
1057 KBUILD_CFLAGS   += $(KCFLAGS)
1058
1059 KBUILD_LDFLAGS_MODULE += --build-id=sha1
1060 LDFLAGS_vmlinux += --build-id=sha1
1061
1062 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1063 LDFLAGS_vmlinux += $(call ld-option, -X,)
1064 endif
1065
1066 ifeq ($(CONFIG_RELR),y)
1067 LDFLAGS_vmlinux += --pack-dyn-relocs=relr --use-android-relr-tags
1068 endif
1069
1070 # We never want expected sections to be placed heuristically by the
1071 # linker. All sections should be explicitly named in the linker script.
1072 ifdef CONFIG_LD_ORPHAN_WARN
1073 LDFLAGS_vmlinux += --orphan-handling=warn
1074 endif
1075
1076 # Align the bit size of userspace programs with the kernel
1077 KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1078 KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1079
1080 # make the checker run with the right architecture
1081 CHECKFLAGS += --arch=$(ARCH)
1082
1083 # insure the checker run with the right endianness
1084 CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1085
1086 # the checker needs the correct machine size
1087 CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1088
1089 # Default kernel image to build when no specific target is given.
1090 # KBUILD_IMAGE may be overruled on the command line or
1091 # set in the environment
1092 # Also any assignments in arch/$(ARCH)/Makefile take precedence over
1093 # this default value
1094 export KBUILD_IMAGE ?= vmlinux
1095
1096 #
1097 # INSTALL_PATH specifies where to place the updated kernel and system map
1098 # images. Default is /boot, but you can set it to other values
1099 export  INSTALL_PATH ?= /boot
1100
1101 #
1102 # INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1103 # Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1104 # an argument if needed. Otherwise it defaults to the kernel install path
1105 #
1106 export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1107
1108 #
1109 # INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1110 # relocations required by build roots.  This is not defined in the
1111 # makefile but the argument can be passed to make if needed.
1112 #
1113
1114 MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1115 export MODLIB
1116
1117 PHONY += prepare0
1118
1119 export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1120 export MODORDER := $(extmod_prefix)modules.order
1121 export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1122
1123 ifeq ($(KBUILD_EXTMOD),)
1124 core-y          += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1125
1126 vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1127                      $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1128                      $(libs-y) $(libs-m)))
1129
1130 vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1131                      $(patsubst %/,%,$(filter %/, $(core-) \
1132                         $(drivers-) $(libs-))))
1133
1134 subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1135                         $(core-y) $(core-m) $(libs-y) $(libs-m) \
1136                         $(drivers-y) $(drivers-m)))
1137
1138 build-dirs      := $(vmlinux-dirs)
1139 clean-dirs      := $(vmlinux-alldirs)
1140
1141 # Externally visible symbols (used by link-vmlinux.sh)
1142 KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1143 KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1144 ifdef CONFIG_MODULES
1145 KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1146 KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1147 else
1148 KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1149 endif
1150 KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1151
1152 export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1153 export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1154 # used by scripts/Makefile.package
1155 export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1156
1157 vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1158
1159 # Recurse until adjust_autoksyms.sh is satisfied
1160 PHONY += autoksyms_recursive
1161 ifdef CONFIG_TRIM_UNUSED_KSYMS
1162 # For the kernel to actually contain only the needed exported symbols,
1163 # we have to build modules as well to determine what those symbols are.
1164 # (this can be evaluated only once include/config/auto.conf has been included)
1165 KBUILD_MODULES := 1
1166
1167 autoksyms_recursive: descend modules.order
1168         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1169           "$(MAKE) -f $(srctree)/Makefile vmlinux"
1170 endif
1171
1172 autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1173
1174 quiet_cmd_autoksyms_h = GEN     $@
1175       cmd_autoksyms_h = mkdir -p $(dir $@); \
1176                         $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1177
1178 $(autoksyms_h):
1179         $(call cmd,autoksyms_h)
1180
1181 ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1182
1183 # Final link of vmlinux with optional arch pass after final link
1184 cmd_link-vmlinux =                                                 \
1185         $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1186         $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1187
1188 vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1189         +$(call if_changed_dep,link-vmlinux)
1190
1191 targets := vmlinux
1192
1193 # The actual objects are generated when descending,
1194 # make sure no implicit rule kicks in
1195 $(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1196
1197 filechk_kernel.release = \
1198         echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1199
1200 # Store (new) KERNELRELEASE string in include/config/kernel.release
1201 include/config/kernel.release: FORCE
1202         $(call filechk,kernel.release)
1203
1204 # Additional helpers built in scripts/
1205 # Carefully list dependencies so we do not try to build scripts twice
1206 # in parallel
1207 PHONY += scripts
1208 scripts: scripts_basic scripts_dtc
1209         $(Q)$(MAKE) $(build)=$(@)
1210
1211 # Things we need to do before we recursively start building the kernel
1212 # or the modules are listed in "prepare".
1213 # A multi level approach is used. prepareN is processed before prepareN-1.
1214 # archprepare is used in arch Makefiles and when processed asm symlink,
1215 # version.h and scripts_basic is processed / created.
1216
1217 PHONY += prepare archprepare
1218
1219 archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1220         asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1221         include/generated/autoconf.h remove-stale-files
1222
1223 prepare0: archprepare
1224         $(Q)$(MAKE) $(build)=scripts/mod
1225         $(Q)$(MAKE) $(build)=.
1226
1227 # All the preparing..
1228 prepare: prepare0
1229
1230 PHONY += remove-stale-files
1231 remove-stale-files:
1232         $(Q)$(srctree)/scripts/remove-stale-files
1233
1234 # Support for using generic headers in asm-generic
1235 asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1236
1237 PHONY += asm-generic uapi-asm-generic
1238 asm-generic: uapi-asm-generic
1239         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1240         generic=include/asm-generic
1241 uapi-asm-generic:
1242         $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1243         generic=include/uapi/asm-generic
1244
1245 # Generate some files
1246 # ---------------------------------------------------------------------------
1247
1248 # KERNELRELEASE can change from a few different places, meaning version.h
1249 # needs to be updated, so this check is forced on all builds
1250
1251 uts_len := 64
1252 define filechk_utsrelease.h
1253         if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1254           echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1255           exit 1;                                                         \
1256         fi;                                                               \
1257         echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1258 endef
1259
1260 define filechk_version.h
1261         if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1262                 echo \#define LINUX_VERSION_CODE $(shell                 \
1263                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1264         else                                                             \
1265                 echo \#define LINUX_VERSION_CODE $(shell                 \
1266                 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1267         fi;                                                              \
1268         echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1269         ((c) > 255 ? 255 : (c)))';                                       \
1270         echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1271         echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1272         echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1273 endef
1274
1275 $(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1276 $(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1277 $(version_h): FORCE
1278         $(call filechk,version.h)
1279
1280 include/generated/utsrelease.h: include/config/kernel.release FORCE
1281         $(call filechk,utsrelease.h)
1282
1283 PHONY += headerdep
1284 headerdep:
1285         $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1286         $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1287
1288 # ---------------------------------------------------------------------------
1289 # Kernel headers
1290
1291 #Default location for installed headers
1292 export INSTALL_HDR_PATH = $(objtree)/usr
1293
1294 quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1295       cmd_headers_install = \
1296         mkdir -p $(INSTALL_HDR_PATH); \
1297         rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1298         usr/include $(INSTALL_HDR_PATH)
1299
1300 PHONY += headers_install
1301 headers_install: headers
1302         $(call cmd,headers_install)
1303
1304 PHONY += archheaders archscripts
1305
1306 hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1307
1308 PHONY += headers
1309 headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1310         $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1311           $(error Headers not exportable for the $(SRCARCH) architecture))
1312         $(Q)$(MAKE) $(hdr-inst)=include/uapi
1313         $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1314         $(Q)$(MAKE) $(hdr-inst)=ubuntu/include dst=include oldheaders=
1315
1316 # Deprecated. It is no-op now.
1317 PHONY += headers_check
1318 headers_check:
1319         @echo >&2 "=================== WARNING ==================="
1320         @echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1321         @echo >&2 "and will be removed after Linux 5.15 release."
1322         @echo >&2 "Please remove headers_check from your scripts."
1323         @echo >&2 "==============================================="
1324
1325 ifdef CONFIG_HEADERS_INSTALL
1326 prepare: headers
1327 endif
1328
1329 PHONY += scripts_unifdef
1330 scripts_unifdef: scripts_basic
1331         $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1332
1333 # ---------------------------------------------------------------------------
1334 # Install
1335
1336 # Many distributions have the custom install script, /sbin/installkernel.
1337 # If DKMS is installed, 'make install' will eventually recuses back
1338 # to the this Makefile to build and install external modules.
1339 # Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1340
1341 install: sub_make_done :=
1342
1343 # ---------------------------------------------------------------------------
1344 # Tools
1345
1346 ifdef CONFIG_STACK_VALIDATION
1347 prepare: tools/objtool
1348 endif
1349
1350 ifdef CONFIG_BPF
1351 ifdef CONFIG_DEBUG_INFO_BTF
1352 prepare: tools/bpf/resolve_btfids
1353 endif
1354 endif
1355
1356 PHONY += resolve_btfids_clean
1357
1358 resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1359
1360 # tools/bpf/resolve_btfids directory might not exist
1361 # in output directory, skip its clean in that case
1362 resolve_btfids_clean:
1363 ifneq ($(wildcard $(resolve_btfids_O)),)
1364         $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1365 endif
1366
1367 # Clear a bunch of variables before executing the submake
1368 ifeq ($(quiet),silent_)
1369 tools_silent=s
1370 endif
1371
1372 tools/: FORCE
1373         $(Q)mkdir -p $(objtree)/tools
1374         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1375
1376 tools/%: FORCE
1377         $(Q)mkdir -p $(objtree)/tools
1378         $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1379
1380 # ---------------------------------------------------------------------------
1381 # Kernel selftest
1382
1383 PHONY += kselftest
1384 kselftest:
1385         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1386
1387 kselftest-%: FORCE
1388         $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1389
1390 PHONY += kselftest-merge
1391 kselftest-merge:
1392         $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1393         $(Q)find $(srctree)/tools/testing/selftests -name config | \
1394                 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1395         $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1396
1397 # ---------------------------------------------------------------------------
1398 # Devicetree files
1399
1400 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1401 dtstree := arch/$(SRCARCH)/boot/dts
1402 endif
1403
1404 ifneq ($(dtstree),)
1405
1406 %.dtb: include/config/kernel.release scripts_dtc
1407         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1408
1409 %.dtbo: include/config/kernel.release scripts_dtc
1410         $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1411
1412 PHONY += dtbs dtbs_install dtbs_check
1413 dtbs: include/config/kernel.release scripts_dtc
1414         $(Q)$(MAKE) $(build)=$(dtstree)
1415
1416 ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1417 export CHECK_DTBS=y
1418 dtbs: dt_binding_check
1419 endif
1420
1421 dtbs_check: dtbs
1422
1423 dtbs_install:
1424         $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1425
1426 ifdef CONFIG_OF_EARLY_FLATTREE
1427 all: dtbs
1428 endif
1429
1430 endif
1431
1432 PHONY += scripts_dtc
1433 scripts_dtc: scripts_basic
1434         $(Q)$(MAKE) $(build)=scripts/dtc
1435
1436 ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1437 export CHECK_DT_BINDING=y
1438 endif
1439
1440 PHONY += dt_binding_check
1441 dt_binding_check: scripts_dtc
1442         $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1443
1444 # ---------------------------------------------------------------------------
1445 # Modules
1446
1447 ifdef CONFIG_MODULES
1448
1449 # By default, build modules as well
1450
1451 all: modules
1452
1453 # When we're building modules with modversions, we need to consider
1454 # the built-in objects during the descend as well, in order to
1455 # make sure the checksums are up to date before we record them.
1456 ifdef CONFIG_MODVERSIONS
1457   KBUILD_BUILTIN := 1
1458 endif
1459
1460 # Build modules
1461 #
1462 # A module can be listed more than once in obj-m resulting in
1463 # duplicate lines in modules.order files.  Those are removed
1464 # using awk while concatenating to the final file.
1465
1466 PHONY += modules
1467 modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1468
1469 cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1470
1471 modules.order: $(subdir-modorder) FORCE
1472         $(call if_changed,modules_order)
1473
1474 targets += modules.order
1475
1476 # Target to prepare building external modules
1477 PHONY += modules_prepare
1478 modules_prepare: prepare
1479         $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1480
1481 export modules_sign_only :=
1482
1483 ifeq ($(CONFIG_MODULE_SIG),y)
1484 PHONY += modules_sign
1485 modules_sign: modules_install
1486         @:
1487
1488 # modules_sign is a subset of modules_install.
1489 # 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1490 ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1491 modules_sign_only := y
1492 endif
1493 endif
1494
1495 modinst_pre :=
1496 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1497 modinst_pre := __modinst_pre
1498 endif
1499
1500 modules_install: $(modinst_pre)
1501 PHONY += __modinst_pre
1502 __modinst_pre:
1503         @rm -rf $(MODLIB)/kernel
1504         @rm -f $(MODLIB)/source
1505         @mkdir -p $(MODLIB)/kernel
1506         @ln -s $(abspath $(srctree)) $(MODLIB)/source
1507         @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1508                 rm -f $(MODLIB)/build ; \
1509                 ln -s $(CURDIR) $(MODLIB)/build ; \
1510         fi
1511         @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1512         @cp -f modules.builtin $(MODLIB)/
1513         @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1514
1515 endif # CONFIG_MODULES
1516
1517 ###
1518 # Cleaning is done on three levels.
1519 # make clean     Delete most generated files
1520 #                Leave enough to build external modules
1521 # make mrproper  Delete the current configuration, and all generated files
1522 # make distclean Remove editor backup files, patch leftover files and the like
1523
1524 # Directories & files removed with 'make clean'
1525 CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1526                modules.builtin modules.builtin.modinfo modules.nsdeps \
1527                compile_commands.json .thinlto-cache
1528
1529 # Directories & files removed with 'make mrproper'
1530 MRPROPER_FILES += include/config include/generated          \
1531                   arch/$(SRCARCH)/include/generated .tmp_objdiff \
1532                   debian snap tar-install \
1533                   .config .config.old .version \
1534                   Module.symvers \
1535                   certs/signing_key.pem certs/signing_key.x509 \
1536                   certs/x509.genkey \
1537                   vmlinux-gdb.py \
1538                   *.spec
1539
1540 # clean - Delete most, but leave enough to build external modules
1541 #
1542 clean: rm-files := $(CLEAN_FILES)
1543
1544 PHONY += archclean vmlinuxclean
1545
1546 vmlinuxclean:
1547         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1548         $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1549
1550 clean: archclean vmlinuxclean resolve_btfids_clean
1551
1552 # mrproper - Delete all generated files, including .config
1553 #
1554 mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1555 mrproper-dirs      := $(addprefix _mrproper_,scripts)
1556
1557 PHONY += $(mrproper-dirs) mrproper
1558 $(mrproper-dirs):
1559         $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1560
1561 mrproper: clean $(mrproper-dirs)
1562         $(call cmd,rmfiles)
1563
1564 # distclean
1565 #
1566 PHONY += distclean
1567
1568 distclean: mrproper
1569         @find . $(RCS_FIND_IGNORE) \
1570                 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1571                 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1572                 -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1573                 -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1574                 -type f -print | xargs rm -f
1575
1576
1577 # Packaging of the kernel to various formats
1578 # ---------------------------------------------------------------------------
1579
1580 %src-pkg: FORCE
1581         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1582 %pkg: include/config/kernel.release FORCE
1583         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1584
1585 # Brief documentation of the typical targets used
1586 # ---------------------------------------------------------------------------
1587
1588 boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1589 boards := $(sort $(notdir $(boards)))
1590 board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1591 board-dirs := $(sort $(notdir $(board-dirs:/=)))
1592
1593 PHONY += help
1594 help:
1595         @echo  'Cleaning targets:'
1596         @echo  '  clean           - Remove most generated files but keep the config and'
1597         @echo  '                    enough build support to build external modules'
1598         @echo  '  mrproper        - Remove all generated files + config + various backup files'
1599         @echo  '  distclean       - mrproper + remove editor backup and patch files'
1600         @echo  ''
1601         @echo  'Configuration targets:'
1602         @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1603         @echo  ''
1604         @echo  'Other generic targets:'
1605         @echo  '  all             - Build all targets marked with [*]'
1606         @echo  '* vmlinux         - Build the bare kernel'
1607         @echo  '* modules         - Build all modules'
1608         @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1609         @echo  '  dir/            - Build all files in dir and below'
1610         @echo  '  dir/file.[ois]  - Build specified target only'
1611         @echo  '  dir/file.ll     - Build the LLVM assembly file'
1612         @echo  '                    (requires compiler support for LLVM assembly generation)'
1613         @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1614         @echo  '                    (requires a recent binutils and recent build (System.map))'
1615         @echo  '  dir/file.ko     - Build module including final link'
1616         @echo  '  modules_prepare - Set up for building external modules'
1617         @echo  '  tags/TAGS       - Generate tags file for editors'
1618         @echo  '  cscope          - Generate cscope index'
1619         @echo  '  gtags           - Generate GNU GLOBAL index'
1620         @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1621         @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1622         @echo  '  image_name      - Output the image name (use with make -s)'
1623         @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1624          echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1625          echo  ''
1626         @echo  'Static analysers:'
1627         @echo  '  checkstack      - Generate a list of stack hogs'
1628         @echo  '  versioncheck    - Sanity check on version.h usage'
1629         @echo  '  includecheck    - Check for duplicate included header files'
1630         @echo  '  export_report   - List the usages of all exported symbols'
1631         @echo  '  headerdep       - Detect inclusion cycles in headers'
1632         @echo  '  coccicheck      - Check with Coccinelle'
1633         @echo  '  clang-analyzer  - Check with clang static analyzer'
1634         @echo  '  clang-tidy      - Check with clang-tidy'
1635         @echo  ''
1636         @echo  'Tools:'
1637         @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1638         @echo  ''
1639         @echo  'Kernel selftest:'
1640         @echo  '  kselftest         - Build and run kernel selftest'
1641         @echo  '                      Build, install, and boot kernel before'
1642         @echo  '                      running kselftest on it'
1643         @echo  '                      Run as root for full coverage'
1644         @echo  '  kselftest-all     - Build kernel selftest'
1645         @echo  '  kselftest-install - Build and install kernel selftest'
1646         @echo  '  kselftest-clean   - Remove all generated kselftest files'
1647         @echo  '  kselftest-merge   - Merge all the config dependencies of'
1648         @echo  '                      kselftest to existing .config.'
1649         @echo  ''
1650         @$(if $(dtstree), \
1651                 echo 'Devicetree:'; \
1652                 echo '* dtbs             - Build device tree blobs for enabled boards'; \
1653                 echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1654                 echo '  dt_binding_check - Validate device tree binding documents'; \
1655                 echo '  dtbs_check       - Validate device tree source files';\
1656                 echo '')
1657
1658         @echo 'Userspace tools targets:'
1659         @echo '  use "make tools/help"'
1660         @echo '  or  "cd tools; make help"'
1661         @echo  ''
1662         @echo  'Kernel packaging:'
1663         @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1664         @echo  ''
1665         @echo  'Documentation targets:'
1666         @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1667         @echo  ''
1668         @echo  'Architecture specific targets ($(SRCARCH)):'
1669         @$(if $(archhelp),$(archhelp),\
1670                 echo '  No architecture specific help defined for $(SRCARCH)')
1671         @echo  ''
1672         @$(if $(boards), \
1673                 $(foreach b, $(boards), \
1674                 printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1675                 echo '')
1676         @$(if $(board-dirs), \
1677                 $(foreach b, $(board-dirs), \
1678                 printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1679                 printf "  %-16s - Show all of the above\\n" help-boards; \
1680                 echo '')
1681
1682         @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1683         @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1684         @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1685         @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1686         @echo  '                       (sparse by default)'
1687         @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1688         @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1689         @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1690         @echo  '                1: warnings which may be relevant and do not occur too often'
1691         @echo  '                2: warnings which occur quite often but may still be relevant'
1692         @echo  '                3: more obscure warnings, can most likely be ignored'
1693         @echo  '                Multiple levels can be combined with W=12 or W=123'
1694         @echo  ''
1695         @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1696         @echo  'For further info see the ./README file'
1697
1698
1699 help-board-dirs := $(addprefix help-,$(board-dirs))
1700
1701 help-boards: $(help-board-dirs)
1702
1703 boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1704
1705 $(help-board-dirs): help-%:
1706         @echo  'Architecture specific targets ($(SRCARCH) $*):'
1707         @$(if $(boards-per-dir), \
1708                 $(foreach b, $(boards-per-dir), \
1709                 printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1710                 echo '')
1711
1712
1713 # Documentation targets
1714 # ---------------------------------------------------------------------------
1715 DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1716                linkcheckdocs dochelp refcheckdocs
1717 PHONY += $(DOC_TARGETS)
1718 $(DOC_TARGETS):
1719         $(Q)$(MAKE) $(build)=Documentation $@
1720
1721 # Misc
1722 # ---------------------------------------------------------------------------
1723
1724 PHONY += scripts_gdb
1725 scripts_gdb: prepare0
1726         $(Q)$(MAKE) $(build)=scripts/gdb
1727         $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1728
1729 ifdef CONFIG_GDB_SCRIPTS
1730 all: scripts_gdb
1731 endif
1732
1733 else # KBUILD_EXTMOD
1734
1735 ###
1736 # External module support.
1737 # When building external modules the kernel used as basis is considered
1738 # read-only, and no consistency checks are made and the make
1739 # system is not used on the basis kernel. If updates are required
1740 # in the basis kernel ordinary make commands (without M=...) must be used.
1741
1742 # We are always building only modules.
1743 KBUILD_BUILTIN :=
1744 KBUILD_MODULES := 1
1745
1746 build-dirs := $(KBUILD_EXTMOD)
1747 $(MODORDER): descend
1748         @:
1749
1750 compile_commands.json: $(extmod_prefix)compile_commands.json
1751 PHONY += compile_commands.json
1752
1753 clean-dirs := $(KBUILD_EXTMOD)
1754 clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1755         $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1756
1757 PHONY += prepare
1758 # now expand this into a simple variable to reduce the cost of shell evaluations
1759 prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1760 prepare:
1761         @if [ "$(CC_VERSION_TEXT)" != $(CONFIG_CC_VERSION_TEXT) ]; then \
1762                 echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1763                 echo >&2 "  The kernel was built by: "$(CONFIG_CC_VERSION_TEXT); \
1764                 echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1765         fi
1766
1767 PHONY += help
1768 help:
1769         @echo  '  Building external modules.'
1770         @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1771         @echo  ''
1772         @echo  '  modules         - default target, build the module(s)'
1773         @echo  '  modules_install - install the module'
1774         @echo  '  clean           - remove generated files in module directory only'
1775         @echo  ''
1776
1777 # no-op for external module builds
1778 PHONY += modules_prepare
1779
1780 endif # KBUILD_EXTMOD
1781
1782 # ---------------------------------------------------------------------------
1783 # Modules
1784
1785 PHONY += modules modules_install
1786
1787 ifdef CONFIG_MODULES
1788
1789 modules: modules_check
1790         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1791
1792 PHONY += modules_check
1793 modules_check: $(MODORDER)
1794         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1795
1796 quiet_cmd_depmod = DEPMOD  $(MODLIB)
1797       cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1798                    $(KERNELRELEASE)
1799
1800 modules_install:
1801         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1802         $(call cmd,depmod)
1803
1804 else # CONFIG_MODULES
1805
1806 # Modules not configured
1807 # ---------------------------------------------------------------------------
1808
1809 modules modules_install:
1810         @echo >&2 '***'
1811         @echo >&2 '*** The present kernel configuration has modules disabled.'
1812         @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1813         @echo >&2 '*** to enable CONFIG_MODULES.'
1814         @echo >&2 '***'
1815         @exit 1
1816
1817 endif # CONFIG_MODULES
1818
1819 # Single targets
1820 # ---------------------------------------------------------------------------
1821 # To build individual files in subdirectories, you can do like this:
1822 #
1823 #   make foo/bar/baz.s
1824 #
1825 # The supported suffixes for single-target are listed in 'single-targets'
1826 #
1827 # To build only under specific subdirectories, you can do like this:
1828 #
1829 #   make foo/bar/baz/
1830
1831 ifdef single-build
1832
1833 # .ko is special because modpost is needed
1834 single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1835 single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1836
1837 $(single-ko): single_modpost
1838         @:
1839 $(single-no-ko): descend
1840         @:
1841
1842 ifeq ($(KBUILD_EXTMOD),)
1843 # For the single build of in-tree modules, use a temporary file to avoid
1844 # the situation of modules_install installing an invalid modules.order.
1845 MODORDER := .modules.tmp
1846 endif
1847
1848 PHONY += single_modpost
1849 single_modpost: $(single-no-ko) modules_prepare
1850         $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1851         $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1852
1853 KBUILD_MODULES := 1
1854
1855 export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1856
1857 # trim unrelated directories
1858 build-dirs := $(foreach d, $(build-dirs), \
1859                         $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1860
1861 endif
1862
1863 ifndef CONFIG_MODULES
1864 KBUILD_MODULES :=
1865 endif
1866
1867 # Handle descending into subdirectories listed in $(build-dirs)
1868 # Preset locale variables to speed up the build process. Limit locale
1869 # tweaks to this spot to avoid wrong language settings when running
1870 # make menuconfig etc.
1871 # Error messages still appears in the original language
1872 PHONY += descend $(build-dirs)
1873 descend: $(build-dirs)
1874 $(build-dirs): prepare
1875         $(Q)$(MAKE) $(build)=$@ \
1876         single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1877         need-builtin=1 need-modorder=1
1878
1879 clean-dirs := $(addprefix _clean_, $(clean-dirs))
1880 PHONY += $(clean-dirs) clean
1881 $(clean-dirs):
1882         $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1883
1884 clean: $(clean-dirs)
1885         $(call cmd,rmfiles)
1886         @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1887                 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1888                 -o -name '*.ko.*' \
1889                 -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1890                 -o -name '*.dwo' -o -name '*.lst' \
1891                 -o -name '*.su' -o -name '*.mod' \
1892                 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1893                 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1894                 -o -name '*.asn1.[ch]' \
1895                 -o -name '*.symtypes' -o -name 'modules.order' \
1896                 -o -name '.tmp_*.o.*' \
1897                 -o -name '*.c.[012]*.*' \
1898                 -o -name '*.ll' \
1899                 -o -name '*.gcno' \
1900                 -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1901
1902 # Generate tags for editors
1903 # ---------------------------------------------------------------------------
1904 quiet_cmd_tags = GEN     $@
1905       cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1906
1907 tags TAGS cscope gtags: FORCE
1908         $(call cmd,tags)
1909
1910 # Script to generate missing namespace dependencies
1911 # ---------------------------------------------------------------------------
1912
1913 PHONY += nsdeps
1914 nsdeps: export KBUILD_NSDEPS=1
1915 nsdeps: modules
1916         $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1917
1918 # Clang Tooling
1919 # ---------------------------------------------------------------------------
1920
1921 quiet_cmd_gen_compile_commands = GEN     $@
1922       cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1923
1924 $(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1925         $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1926         $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1927         $(call if_changed,gen_compile_commands)
1928
1929 targets += $(extmod_prefix)compile_commands.json
1930
1931 PHONY += clang-tidy clang-analyzer
1932
1933 ifdef CONFIG_CC_IS_CLANG
1934 quiet_cmd_clang_tools = CHECK   $<
1935       cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1936
1937 clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1938         $(call cmd,clang_tools)
1939 else
1940 clang-tidy clang-analyzer:
1941         @echo "$@ requires CC=clang" >&2
1942         @false
1943 endif
1944
1945 # Scripts to check various things for consistency
1946 # ---------------------------------------------------------------------------
1947
1948 PHONY += includecheck versioncheck coccicheck export_report
1949
1950 includecheck:
1951         find $(srctree)/* $(RCS_FIND_IGNORE) \
1952                 -name '*.[hcS]' -type f -print | sort \
1953                 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1954
1955 versioncheck:
1956         find $(srctree)/* $(RCS_FIND_IGNORE) \
1957                 -name '*.[hcS]' -type f -print | sort \
1958                 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1959
1960 coccicheck:
1961         $(Q)$(BASH) $(srctree)/scripts/$@
1962
1963 export_report:
1964         $(PERL) $(srctree)/scripts/export_report.pl
1965
1966 PHONY += checkstack kernelrelease kernelversion image_name
1967
1968 # UML needs a little special treatment here.  It wants to use the host
1969 # toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1970 # else wants $(ARCH), including people doing cross-builds, which means
1971 # that $(SUBARCH) doesn't work here.
1972 ifeq ($(ARCH), um)
1973 CHECKSTACK_ARCH := $(SUBARCH)
1974 else
1975 CHECKSTACK_ARCH := $(ARCH)
1976 endif
1977 checkstack:
1978         $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1979         $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1980
1981 kernelrelease:
1982         @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1983
1984 kernelversion:
1985         @echo $(KERNELVERSION)
1986
1987 image_name:
1988         @echo $(KBUILD_IMAGE)
1989
1990 quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1991       cmd_rmfiles = rm -rf $(rm-files)
1992
1993 # read saved command lines for existing targets
1994 existing-targets := $(wildcard $(sort $(targets)))
1995
1996 -include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1997
1998 endif # config-build
1999 endif # mixed-build
2000 endif # need-sub-make
2001
2002 PHONY += FORCE
2003 FORCE:
2004
2005 # Declare the contents of the PHONY variable as phony.  We keep that
2006 # information in a variable so we can use it in if_changed and friends.
2007 .PHONY: $(PHONY)