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