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   1# SPDX-License-Identifier: GPL-2.0
   2VERSION = 5
   3PATCHLEVEL = 13
   4SUBLEVEL = 11
   5EXTRAVERSION =
   6NAME = Opossums on Parade
   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 --%,$(MAKEFLAGS))),)
  98  quiet=silent_
  99  KBUILD_VERBOSE = 0
 100endif
 101
 102export quiet Q KBUILD_VERBOSE
 103
 104# Call a source code checker (by default, "sparse") as part of the
 105# C compilation.
 106#
 107# Use 'make C=1' to enable checking of only re-compiled files.
 108# Use 'make C=2' to enable checking of *all* source files, regardless
 109# of whether they are re-compiled or not.
 110#
 111# See the file "Documentation/dev-tools/sparse.rst" for more details,
 112# including where to get the "sparse" utility.
 113
 114ifeq ("$(origin C)", "command line")
 115  KBUILD_CHECKSRC = $(C)
 116endif
 117ifndef KBUILD_CHECKSRC
 118  KBUILD_CHECKSRC = 0
 119endif
 120
 121export KBUILD_CHECKSRC
 122
 123# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
 124# directory of external module to build. Setting M= takes precedence.
 125ifeq ("$(origin M)", "command line")
 126  KBUILD_EXTMOD := $(M)
 127endif
 128
 129$(if $(word 2, $(KBUILD_EXTMOD)), \
 130        $(error building multiple external modules is not supported))
 131
 132# Remove trailing slashes
 133ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
 134KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
 135endif
 136
 137export KBUILD_EXTMOD
 138
 139# Kbuild will save output files in the current working directory.
 140# This does not need to match to the root of the kernel source tree.
 141#
 142# For example, you can do this:
 143#
 144#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
 145#
 146# If you want to save output files in a different location, there are
 147# two syntaxes to specify it.
 148#
 149# 1) O=
 150# Use "make O=dir/to/store/output/files/"
 151#
 152# 2) Set KBUILD_OUTPUT
 153# Set the environment variable KBUILD_OUTPUT to point to the output directory.
 154# export KBUILD_OUTPUT=dir/to/store/output/files/; make
 155#
 156# The O= assignment takes precedence over the KBUILD_OUTPUT environment
 157# variable.
 158
 159# Do we want to change the working directory?
 160ifeq ("$(origin O)", "command line")
 161  KBUILD_OUTPUT := $(O)
 162endif
 163
 164ifneq ($(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.
 167abs_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
 172abs_objtree := $(realpath $(abs_objtree))
 173else
 174abs_objtree := $(CURDIR)
 175endif # ifneq ($(KBUILD_OUTPUT),)
 176
 177ifeq ($(abs_objtree),$(CURDIR))
 178# Suppress "Entering directory ..." unless we are changing the work directory.
 179MAKEFLAGS += --no-print-directory
 180else
 181need-sub-make := 1
 182endif
 183
 184this-makefile := $(lastword $(MAKEFILE_LIST))
 185abs_srctree := $(realpath $(dir $(this-makefile)))
 186
 187ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
 188$(error source directory cannot contain spaces or colons)
 189endif
 190
 191ifneq ($(abs_srctree),$(abs_objtree))
 192# Look for make include files relative to root of kernel src
 193#
 194# This does not become effective immediately because MAKEFLAGS is re-parsed
 195# once after the Makefile is read. We need to invoke sub-make.
 196MAKEFLAGS += --include-dir=$(abs_srctree)
 197need-sub-make := 1
 198endif
 199
 200ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 201# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
 202# We need to invoke sub-make to avoid implicit rules in the top Makefile.
 203need-sub-make := 1
 204# Cancel implicit rules for this Makefile.
 205$(this-makefile): ;
 206endif
 207
 208export abs_srctree abs_objtree
 209export sub_make_done := 1
 210
 211ifeq ($(need-sub-make),1)
 212
 213PHONY += $(MAKECMDGOALS) __sub-make
 214
 215$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 216        @:
 217
 218# Invoke a second make in the output directory, passing relevant variables
 219__sub-make:
 220        $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 221
 222endif # need-sub-make
 223endif # sub_make_done
 224
 225# We process the rest of the Makefile if this is the final invocation of make
 226ifeq ($(need-sub-make),)
 227
 228# Do not print "Entering directory ...",
 229# but we want to display it when entering to the output directory
 230# so that IDEs/editors are able to understand relative filenames.
 231MAKEFLAGS += --no-print-directory
 232
 233ifeq ($(abs_srctree),$(abs_objtree))
 234        # building in the source tree
 235        srctree := .
 236        building_out_of_srctree :=
 237else
 238        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
 239                # building in a subdirectory of the source tree
 240                srctree := ..
 241        else
 242                srctree := $(abs_srctree)
 243        endif
 244        building_out_of_srctree := 1
 245endif
 246
 247ifneq ($(KBUILD_ABS_SRCTREE),)
 248srctree := $(abs_srctree)
 249endif
 250
 251objtree         := .
 252VPATH           := $(srctree)
 253
 254export building_out_of_srctree srctree objtree VPATH
 255
 256# To make sure we do not include .config for any of the *config targets
 257# catch them early, and hand them over to scripts/kconfig/Makefile
 258# It is allowed to specify more targets when calling make, including
 259# mixing *config targets and build targets.
 260# For example 'make oldconfig all'.
 261# Detect when mixed targets is specified, and make a second invocation
 262# of make so .config is not included in this case either (for *config).
 263
 264version_h := include/generated/uapi/linux/version.h
 265
 266clean-targets := %clean mrproper cleandocs
 267no-dot-config-targets := $(clean-targets) \
 268                         cscope gtags TAGS tags help% %docs check% coccicheck \
 269                         $(version_h) headers headers_% archheaders archscripts \
 270                         %asm-generic kernelversion %src-pkg dt_binding_check \
 271                         outputmakefile
 272# Installation targets should not require compiler. Unfortunately, vdso_install
 273# is an exception where build artifacts may be updated. This must be fixed.
 274no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
 275                        headers_install modules_install kernelrelease image_name
 276no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
 277                          image_name
 278single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
 279
 280config-build    :=
 281mixed-build     :=
 282need-config     := 1
 283need-compiler   := 1
 284may-sync-config := 1
 285single-build    :=
 286
 287ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 288        ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 289                need-config :=
 290        endif
 291endif
 292
 293ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
 294        ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
 295                need-compiler :=
 296        endif
 297endif
 298
 299ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 300        ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 301                may-sync-config :=
 302        endif
 303endif
 304
 305ifneq ($(KBUILD_EXTMOD),)
 306        may-sync-config :=
 307endif
 308
 309ifeq ($(KBUILD_EXTMOD),)
 310        ifneq ($(filter %config,$(MAKECMDGOALS)),)
 311                config-build := 1
 312                ifneq ($(words $(MAKECMDGOALS)),1)
 313                        mixed-build := 1
 314                endif
 315        endif
 316endif
 317
 318# We cannot build single targets and the others at the same time
 319ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 320        single-build := 1
 321        ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 322                mixed-build := 1
 323        endif
 324endif
 325
 326# For "make -j clean all", "make -j mrproper defconfig all", etc.
 327ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 328        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 329                mixed-build := 1
 330        endif
 331endif
 332
 333# install and modules_install need also be processed one by one
 334ifneq ($(filter install,$(MAKECMDGOALS)),)
 335        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 336                mixed-build := 1
 337        endif
 338endif
 339
 340ifdef mixed-build
 341# ===========================================================================
 342# We're called with mixed targets (*config and build targets).
 343# Handle them one by one.
 344
 345PHONY += $(MAKECMDGOALS) __build_one_by_one
 346
 347$(MAKECMDGOALS): __build_one_by_one
 348        @:
 349
 350__build_one_by_one:
 351        $(Q)set -e; \
 352        for i in $(MAKECMDGOALS); do \
 353                $(MAKE) -f $(srctree)/Makefile $$i; \
 354        done
 355
 356else # !mixed-build
 357
 358include $(srctree)/scripts/Kbuild.include
 359
 360# Read KERNELRELEASE from include/config/kernel.release (if it exists)
 361KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 362KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 363export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 364
 365include $(srctree)/scripts/subarch.include
 366
 367# Cross compiling and selecting different set of gcc/bin-utils
 368# ---------------------------------------------------------------------------
 369#
 370# When performing cross compilation for other architectures ARCH shall be set
 371# to the target architecture. (See arch/* for the possibilities).
 372# ARCH can be set during invocation of make:
 373# make ARCH=ia64
 374# Another way is to have ARCH set in the environment.
 375# The default ARCH is the host where make is executed.
 376
 377# CROSS_COMPILE specify the prefix used for all executables used
 378# during compilation. Only gcc and related bin-utils executables
 379# are prefixed with $(CROSS_COMPILE).
 380# CROSS_COMPILE can be set on the command line
 381# make CROSS_COMPILE=ia64-linux-
 382# Alternatively CROSS_COMPILE can be set in the environment.
 383# Default value for CROSS_COMPILE is not to prefix executables
 384# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 385ARCH            ?= $(SUBARCH)
 386
 387# Architecture as present in compile.h
 388UTS_MACHINE     := $(ARCH)
 389SRCARCH         := $(ARCH)
 390
 391# Additional ARCH settings for x86
 392ifeq ($(ARCH),i386)
 393        SRCARCH := x86
 394endif
 395ifeq ($(ARCH),x86_64)
 396        SRCARCH := x86
 397endif
 398
 399# Additional ARCH settings for sparc
 400ifeq ($(ARCH),sparc32)
 401       SRCARCH := sparc
 402endif
 403ifeq ($(ARCH),sparc64)
 404       SRCARCH := sparc
 405endif
 406
 407export cross_compiling :=
 408ifneq ($(SRCARCH),$(SUBARCH))
 409cross_compiling := 1
 410endif
 411
 412KCONFIG_CONFIG  ?= .config
 413export KCONFIG_CONFIG
 414
 415# SHELL used by kbuild
 416CONFIG_SHELL := sh
 417
 418HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 419HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 420HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 421
 422ifneq ($(LLVM),)
 423HOSTCC  = clang
 424HOSTCXX = clang++
 425else
 426HOSTCC  = gcc
 427HOSTCXX = g++
 428endif
 429
 430export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 431                              -O2 -fomit-frame-pointer -std=gnu89
 432export KBUILD_USERLDFLAGS :=
 433
 434KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 435KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 436KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 437KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 438
 439# Make variables (CC, etc...)
 440CPP             = $(CC) -E
 441ifneq ($(LLVM),)
 442CC              = clang
 443LD              = ld.lld
 444AR              = llvm-ar
 445NM              = llvm-nm
 446OBJCOPY         = llvm-objcopy
 447OBJDUMP         = llvm-objdump
 448READELF         = llvm-readelf
 449STRIP           = llvm-strip
 450else
 451CC              = $(CROSS_COMPILE)gcc
 452LD              = $(CROSS_COMPILE)ld
 453AR              = $(CROSS_COMPILE)ar
 454NM              = $(CROSS_COMPILE)nm
 455OBJCOPY         = $(CROSS_COMPILE)objcopy
 456OBJDUMP         = $(CROSS_COMPILE)objdump
 457READELF         = $(CROSS_COMPILE)readelf
 458STRIP           = $(CROSS_COMPILE)strip
 459endif
 460PAHOLE          = pahole
 461RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 462LEX             = flex
 463YACC            = bison
 464AWK             = awk
 465INSTALLKERNEL  := installkernel
 466DEPMOD          = depmod
 467PERL            = perl
 468PYTHON3         = python3
 469CHECK           = sparse
 470BASH            = bash
 471KGZIP           = gzip
 472KBZIP2          = bzip2
 473KLZOP           = lzop
 474LZMA            = lzma
 475LZ4             = lz4c
 476XZ              = xz
 477ZSTD            = zstd
 478
 479CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 480                  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 481NOSTDINC_FLAGS :=
 482CFLAGS_MODULE   =
 483AFLAGS_MODULE   =
 484LDFLAGS_MODULE  =
 485CFLAGS_KERNEL   =
 486AFLAGS_KERNEL   =
 487LDFLAGS_vmlinux =
 488
 489# Use USERINCLUDE when you must reference the UAPI directories only.
 490USERINCLUDE    := \
 491                -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 492                -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 493                -I$(srctree)/include/uapi \
 494                -I$(objtree)/include/generated/uapi \
 495                -include $(srctree)/include/linux/compiler-version.h \
 496                -include $(srctree)/include/linux/kconfig.h
 497
 498# Use LINUXINCLUDE when you must reference the include/ directory.
 499# Needed to be compatible with the O= option
 500LINUXINCLUDE    := \
 501                -I$(srctree)/arch/$(SRCARCH)/include \
 502                -I$(objtree)/arch/$(SRCARCH)/include/generated \
 503                $(if $(building_out_of_srctree),-I$(srctree)/include) \
 504                -I$(objtree)/include \
 505                $(USERINCLUDE)
 506
 507KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 508KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 509                   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 510                   -Werror=implicit-function-declaration -Werror=implicit-int \
 511                   -Werror=return-type -Wno-format-security \
 512                   -std=gnu89
 513KBUILD_CPPFLAGS := -D__KERNEL__
 514KBUILD_AFLAGS_KERNEL :=
 515KBUILD_CFLAGS_KERNEL :=
 516KBUILD_AFLAGS_MODULE  := -DMODULE
 517KBUILD_CFLAGS_MODULE  := -DMODULE
 518KBUILD_LDFLAGS_MODULE :=
 519KBUILD_LDFLAGS :=
 520CLANG_FLAGS :=
 521
 522export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
 523export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 524export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 525export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 526export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 527
 528export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 529export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 530export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 531export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 532export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 533
 534# Files to ignore in find ... statements
 535
 536export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 537                          -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 538                          -prune -o
 539export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 540                         --exclude CVS --exclude .pc --exclude .hg --exclude .git
 541
 542# ===========================================================================
 543# Rules shared between *config targets and build targets
 544
 545# Basic helpers built in scripts/basic/
 546PHONY += scripts_basic
 547scripts_basic:
 548        $(Q)$(MAKE) $(build)=scripts/basic
 549        $(Q)rm -f .tmp_quiet_recordmcount
 550
 551PHONY += outputmakefile
 552# Before starting out-of-tree build, make sure the source tree is clean.
 553# outputmakefile generates a Makefile in the output directory, if using a
 554# separate output directory. This allows convenient use of make in the
 555# output directory.
 556# At the same time when output Makefile generated, generate .gitignore to
 557# ignore whole output directory
 558outputmakefile:
 559ifdef building_out_of_srctree
 560        $(Q)if [ -f $(srctree)/.config -o \
 561                 -d $(srctree)/include/config -o \
 562                 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 563                echo >&2 "***"; \
 564                echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 565                echo >&2 "*** in $(abs_srctree)";\
 566                echo >&2 "***"; \
 567                false; \
 568        fi
 569        $(Q)ln -fsn $(srctree) source
 570        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
 571        $(Q)test -e .gitignore || \
 572        { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 573endif
 574
 575# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 576# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 577# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 578# and from include/config/auto.conf.cmd to detect the compiler upgrade.
 579CC_VERSION_TEXT = $(subst $(pound),,$(shell $(CC) --version 2>/dev/null | head -n 1))
 580
 581ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 582ifneq ($(CROSS_COMPILE),)
 583CLANG_FLAGS     += --target=$(notdir $(CROSS_COMPILE:%-=%))
 584endif
 585ifeq ($(LLVM_IAS),1)
 586CLANG_FLAGS     += -integrated-as
 587else
 588CLANG_FLAGS     += -no-integrated-as
 589GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
 590CLANG_FLAGS     += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
 591endif
 592CLANG_FLAGS     += -Werror=unknown-warning-option
 593KBUILD_CFLAGS   += $(CLANG_FLAGS)
 594KBUILD_AFLAGS   += $(CLANG_FLAGS)
 595export CLANG_FLAGS
 596endif
 597
 598# Include this also for config targets because some architectures need
 599# cc-cross-prefix to determine CROSS_COMPILE.
 600ifdef need-compiler
 601include $(srctree)/scripts/Makefile.compiler
 602endif
 603
 604ifdef config-build
 605# ===========================================================================
 606# *config targets only - make sure prerequisites are updated, and descend
 607# in scripts/kconfig to make the *config target
 608
 609# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 610# KBUILD_DEFCONFIG may point out an alternative default configuration
 611# used for 'make defconfig'
 612include $(srctree)/arch/$(SRCARCH)/Makefile
 613export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 614
 615config: outputmakefile scripts_basic FORCE
 616        $(Q)$(MAKE) $(build)=scripts/kconfig $@
 617
 618%config: outputmakefile scripts_basic FORCE
 619        $(Q)$(MAKE) $(build)=scripts/kconfig $@
 620
 621else #!config-build
 622# ===========================================================================
 623# Build targets only - this includes vmlinux, arch specific targets, clean
 624# targets and others. In general all targets except *config targets.
 625
 626# If building an external module we do not care about the all: rule
 627# but instead __all depend on modules
 628PHONY += all
 629ifeq ($(KBUILD_EXTMOD),)
 630__all: all
 631else
 632__all: modules
 633endif
 634
 635# Decide whether to build built-in, modular, or both.
 636# Normally, just do built-in.
 637
 638KBUILD_MODULES :=
 639KBUILD_BUILTIN := 1
 640
 641# If we have only "make modules", don't compile built-in objects.
 642ifeq ($(MAKECMDGOALS),modules)
 643  KBUILD_BUILTIN :=
 644endif
 645
 646# If we have "make <whatever> modules", compile modules
 647# in addition to whatever we do anyway.
 648# Just "make" or "make all" shall build modules as well
 649
 650ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 651  KBUILD_MODULES := 1
 652endif
 653
 654ifeq ($(MAKECMDGOALS),)
 655  KBUILD_MODULES := 1
 656endif
 657
 658export KBUILD_MODULES KBUILD_BUILTIN
 659
 660ifdef need-config
 661include include/config/auto.conf
 662endif
 663
 664ifeq ($(KBUILD_EXTMOD),)
 665# Objects we will link into vmlinux / subdirs we need to visit
 666core-y          := init/ usr/
 667drivers-y       := drivers/ sound/
 668drivers-$(CONFIG_SAMPLES) += samples/
 669drivers-$(CONFIG_NET) += net/
 670drivers-y       += virt/
 671libs-y          := lib/
 672endif # KBUILD_EXTMOD
 673
 674# The all: target is the default when no target is given on the
 675# command line.
 676# This allow a user to issue only 'make' to build a kernel including modules
 677# Defaults to vmlinux, but the arch makefile usually adds further targets
 678all: vmlinux
 679
 680CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage \
 681        $(call cc-option,-fno-tree-loop-im) \
 682        $(call cc-disable-warning,maybe-uninitialized,)
 683export CFLAGS_GCOV
 684
 685# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 686ifdef CONFIG_FUNCTION_TRACER
 687  CC_FLAGS_FTRACE := -pg
 688endif
 689
 690RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
 691RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
 692RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
 693RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
 694RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
 695RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
 696export RETPOLINE_CFLAGS
 697export RETPOLINE_VDSO_CFLAGS
 698
 699include $(srctree)/arch/$(SRCARCH)/Makefile
 700
 701ifdef need-config
 702ifdef may-sync-config
 703# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 704# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 705# because some architectures define CROSS_COMPILE there.
 706include include/config/auto.conf.cmd
 707
 708$(KCONFIG_CONFIG):
 709        @echo >&2 '***'
 710        @echo >&2 '*** Configuration file "$@" not found!'
 711        @echo >&2 '***'
 712        @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 713        @echo >&2 '*** "make menuconfig" or "make xconfig").'
 714        @echo >&2 '***'
 715        @/bin/false
 716
 717# The actual configuration files used during the build are stored in
 718# include/generated/ and include/config/. Update them if .config is newer than
 719# include/config/auto.conf (which mirrors .config).
 720#
 721# This exploits the 'multi-target pattern rule' trick.
 722# The syncconfig should be executed only once to make all the targets.
 723# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 724#
 725# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
 726# so you cannot notice that Kconfig is waiting for the user input.
 727%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 728        $(Q)$(kecho) "  SYNC    $@"
 729        $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
 730else # !may-sync-config
 731# External modules and some install targets need include/generated/autoconf.h
 732# and include/config/auto.conf but do not care if they are up-to-date.
 733# Use auto.conf to trigger the test
 734PHONY += include/config/auto.conf
 735
 736include/config/auto.conf:
 737        $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 738        echo >&2;                                                       \
 739        echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 740        echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 741        echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 742        echo >&2 ;                                                      \
 743        /bin/false)
 744
 745endif # may-sync-config
 746endif # need-config
 747
 748KBUILD_CFLAGS   += $(call cc-option,-fno-delete-null-pointer-checks,)
 749KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 750KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 751KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 752KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 753
 754ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 755KBUILD_CFLAGS += -O2
 756else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
 757KBUILD_CFLAGS += -O3
 758else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 759KBUILD_CFLAGS += -Os
 760endif
 761
 762# Tell gcc to never replace conditional load with a non-conditional one
 763KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 764KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 765
 766ifdef CONFIG_READABLE_ASM
 767# Disable optimizations that make assembler listings hard to read.
 768# reorder blocks reorders the control in the function
 769# ipa clone creates specialized cloned functions
 770# partial inlining inlines only parts of functions
 771KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
 772                 $(call cc-option,-fno-ipa-cp-clone,) \
 773                 $(call cc-option,-fno-partial-inlining)
 774endif
 775
 776ifneq ($(CONFIG_FRAME_WARN),0)
 777KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 778endif
 779
 780stackp-flags-y                                    := -fno-stack-protector
 781stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 782stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 783
 784KBUILD_CFLAGS += $(stackp-flags-y)
 785
 786ifdef CONFIG_CC_IS_CLANG
 787KBUILD_CPPFLAGS += -Qunused-arguments
 788KBUILD_CFLAGS += -Wno-format-invalid-specifier
 789KBUILD_CFLAGS += -Wno-gnu
 790# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 791# source of a reference will be _MergedGlobals and not on of the whitelisted names.
 792# See modpost pattern 2
 793KBUILD_CFLAGS += -mno-global-merge
 794else
 795
 796# Warn about unmarked fall-throughs in switch statement.
 797# Disabled for clang while comment to attribute conversion happens and
 798# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
 799KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
 800endif
 801
 802# These warnings generated too much noise in a regular build.
 803# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 804KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 805
 806KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 807ifdef CONFIG_FRAME_POINTER
 808KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 809else
 810# Some targets (ARM with Thumb2, for example), can't be built with frame
 811# pointers.  For those, we don't have FUNCTION_TRACER automatically
 812# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 813# incompatible with -fomit-frame-pointer with current GCC, so we don't use
 814# -fomit-frame-pointer with FUNCTION_TRACER.
 815ifndef CONFIG_FUNCTION_TRACER
 816KBUILD_CFLAGS   += -fomit-frame-pointer
 817endif
 818endif
 819
 820# Initialize all stack variables with a 0xAA pattern.
 821ifdef CONFIG_INIT_STACK_ALL_PATTERN
 822KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 823endif
 824
 825# Initialize all stack variables with a zero value.
 826ifdef CONFIG_INIT_STACK_ALL_ZERO
 827# Future support for zero initialization is still being debated, see
 828# https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
 829# renamed or dropped.
 830KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 831KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 832endif
 833
 834# While VLAs have been removed, GCC produces unreachable stack probes
 835# for the randomize_kstack_offset feature. Disable it for all compilers.
 836KBUILD_CFLAGS   += $(call cc-option, -fno-stack-clash-protection)
 837
 838DEBUG_CFLAGS    :=
 839
 840# Workaround for GCC versions < 5.0
 841# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
 842ifdef CONFIG_CC_IS_GCC
 843DEBUG_CFLAGS    += $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
 844endif
 845
 846ifdef CONFIG_DEBUG_INFO
 847
 848ifdef CONFIG_DEBUG_INFO_SPLIT
 849DEBUG_CFLAGS    += -gsplit-dwarf
 850else
 851DEBUG_CFLAGS    += -g
 852endif
 853
 854ifneq ($(LLVM_IAS),1)
 855KBUILD_AFLAGS   += -Wa,-gdwarf-2
 856endif
 857
 858ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
 859dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
 860dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
 861DEBUG_CFLAGS    += -gdwarf-$(dwarf-version-y)
 862endif
 863
 864ifdef CONFIG_DEBUG_INFO_REDUCED
 865DEBUG_CFLAGS    += $(call cc-option, -femit-struct-debug-baseonly) \
 866                   $(call cc-option,-fno-var-tracking)
 867endif
 868
 869ifdef CONFIG_DEBUG_INFO_COMPRESSED
 870DEBUG_CFLAGS    += -gz=zlib
 871KBUILD_AFLAGS   += -gz=zlib
 872KBUILD_LDFLAGS  += --compress-debug-sections=zlib
 873endif
 874
 875endif # CONFIG_DEBUG_INFO
 876
 877KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 878export DEBUG_CFLAGS
 879
 880ifdef CONFIG_FUNCTION_TRACER
 881ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 882  CC_FLAGS_FTRACE       += -mrecord-mcount
 883  ifdef CONFIG_HAVE_NOP_MCOUNT
 884    ifeq ($(call cc-option-yn, -mnop-mcount),y)
 885      CC_FLAGS_FTRACE   += -mnop-mcount
 886      CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 887    endif
 888  endif
 889endif
 890ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 891  CC_FLAGS_USING        += -DCC_USING_NOP_MCOUNT
 892endif
 893ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 894  ifdef CONFIG_HAVE_C_RECORDMCOUNT
 895    BUILD_C_RECORDMCOUNT := y
 896    export BUILD_C_RECORDMCOUNT
 897  endif
 898endif
 899ifdef CONFIG_HAVE_FENTRY
 900  ifeq ($(call cc-option-yn, -mfentry),y)
 901    CC_FLAGS_FTRACE     += -mfentry
 902    CC_FLAGS_USING      += -DCC_USING_FENTRY
 903  endif
 904endif
 905export CC_FLAGS_FTRACE
 906KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 907KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 908endif
 909
 910# We trigger additional mismatches with less inlining
 911ifdef CONFIG_DEBUG_SECTION_MISMATCH
 912KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 913endif
 914
 915ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 916KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 917LDFLAGS_vmlinux += --gc-sections
 918endif
 919
 920ifdef CONFIG_SHADOW_CALL_STACK
 921CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 922KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 923export CC_FLAGS_SCS
 924endif
 925
 926ifdef CONFIG_LTO_CLANG
 927ifdef CONFIG_LTO_CLANG_THIN
 928CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 929KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
 930else
 931CC_FLAGS_LTO    := -flto
 932endif
 933CC_FLAGS_LTO    += -fvisibility=hidden
 934
 935# Limit inlining across translation units to reduce binary size
 936KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 937
 938# Check for frame size exceeding threshold during prolog/epilog insertion
 939# when using lld < 13.0.0.
 940ifneq ($(CONFIG_FRAME_WARN),0)
 941ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
 942KBUILD_LDFLAGS  += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 943endif
 944endif
 945endif
 946
 947ifdef CONFIG_LTO
 948KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 949KBUILD_AFLAGS   += -fno-lto
 950export CC_FLAGS_LTO
 951endif
 952
 953ifdef CONFIG_CFI_CLANG
 954CC_FLAGS_CFI    := -fsanitize=cfi \
 955                   -fsanitize-cfi-cross-dso \
 956                   -fno-sanitize-cfi-canonical-jump-tables \
 957                   -fno-sanitize-trap=cfi \
 958                   -fno-sanitize-blacklist
 959
 960ifdef CONFIG_CFI_PERMISSIVE
 961CC_FLAGS_CFI    += -fsanitize-recover=cfi
 962endif
 963
 964# If LTO flags are filtered out, we must also filter out CFI.
 965CC_FLAGS_LTO    += $(CC_FLAGS_CFI)
 966KBUILD_CFLAGS   += $(CC_FLAGS_CFI)
 967export CC_FLAGS_CFI
 968endif
 969
 970ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_32B
 971KBUILD_CFLAGS += -falign-functions=32
 972endif
 973
 974# arch Makefile may override CC so keep this after arch Makefile is included
 975NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 976
 977# warn about C99 declaration after statement
 978KBUILD_CFLAGS += -Wdeclaration-after-statement
 979
 980# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 981KBUILD_CFLAGS += -Wvla
 982
 983# disable pointer signed / unsigned warnings in gcc 4.0
 984KBUILD_CFLAGS += -Wno-pointer-sign
 985
 986# disable stringop warnings in gcc 8+
 987KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 988
 989# We'll want to enable this eventually, but it's not going away for 5.7 at least
 990KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
 991KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
 992KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
 993
 994# Another good warning that we'll want to enable eventually
 995KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 996
 997# Enabled with W=2, disabled by default as noisy
 998KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
 999
1000# disable invalid "can't wrap" optimizations for signed / pointers
1001KBUILD_CFLAGS   += -fno-strict-overflow
1002
1003# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1004KBUILD_CFLAGS  += -fno-stack-check
1005
1006# conserve stack if available
1007KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
1008
1009# Prohibit date/time macros, which would make the build non-deterministic
1010KBUILD_CFLAGS   += -Werror=date-time
1011
1012# enforce correct pointer usage
1013KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1014
1015# Require designated initializers for all marked structures
1016KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1017
1018# change __FILE__ to the relative path from the srctree
1019KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1020
1021# include additional Makefiles when needed
1022include-y                       := scripts/Makefile.extrawarn
1023include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
1024include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
1025include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
1026include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
1027include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
1028
1029include $(addprefix $(srctree)/, $(include-y))
1030
1031# scripts/Makefile.gcc-plugins is intentionally included last.
1032# Do not add $(call cc-option,...) below this line. When you build the kernel
1033# from the clean source tree, the GCC plugins do not exist at this point.
1034
1035# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1036KBUILD_CPPFLAGS += $(KCPPFLAGS)
1037KBUILD_AFLAGS   += $(KAFLAGS)
1038KBUILD_CFLAGS   += $(KCFLAGS)
1039
1040KBUILD_LDFLAGS_MODULE += --build-id=sha1
1041LDFLAGS_vmlinux += --build-id=sha1
1042
1043ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1044LDFLAGS_vmlinux += $(call ld-option, -X,)
1045endif
1046
1047ifeq ($(CONFIG_RELR),y)
1048LDFLAGS_vmlinux += --pack-dyn-relocs=relr --use-android-relr-tags
1049endif
1050
1051# We never want expected sections to be placed heuristically by the
1052# linker. All sections should be explicitly named in the linker script.
1053ifdef CONFIG_LD_ORPHAN_WARN
1054LDFLAGS_vmlinux += --orphan-handling=warn
1055endif
1056
1057# Align the bit size of userspace programs with the kernel
1058KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1059KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1060
1061# make the checker run with the right architecture
1062CHECKFLAGS += --arch=$(ARCH)
1063
1064# insure the checker run with the right endianness
1065CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1066
1067# the checker needs the correct machine size
1068CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1069
1070# Default kernel image to build when no specific target is given.
1071# KBUILD_IMAGE may be overruled on the command line or
1072# set in the environment
1073# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1074# this default value
1075export KBUILD_IMAGE ?= vmlinux
1076
1077#
1078# INSTALL_PATH specifies where to place the updated kernel and system map
1079# images. Default is /boot, but you can set it to other values
1080export  INSTALL_PATH ?= /boot
1081
1082#
1083# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1084# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1085# an argument if needed. Otherwise it defaults to the kernel install path
1086#
1087export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1088
1089#
1090# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1091# relocations required by build roots.  This is not defined in the
1092# makefile but the argument can be passed to make if needed.
1093#
1094
1095MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1096export MODLIB
1097
1098HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
1099
1100has_libelf = $(call try-run,\
1101               echo "int main() {}" | $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1102
1103ifdef CONFIG_STACK_VALIDATION
1104  ifeq ($(has_libelf),1)
1105    objtool_target := tools/objtool FORCE
1106  else
1107    SKIP_STACK_VALIDATION := 1
1108    export SKIP_STACK_VALIDATION
1109  endif
1110endif
1111
1112PHONY += resolve_btfids_clean
1113
1114resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1115
1116# tools/bpf/resolve_btfids directory might not exist
1117# in output directory, skip its clean in that case
1118resolve_btfids_clean:
1119ifneq ($(wildcard $(resolve_btfids_O)),)
1120        $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1121endif
1122
1123ifdef CONFIG_BPF
1124ifdef CONFIG_DEBUG_INFO_BTF
1125  ifeq ($(has_libelf),1)
1126    resolve_btfids_target := tools/bpf/resolve_btfids FORCE
1127  else
1128    ERROR_RESOLVE_BTFIDS := 1
1129  endif
1130endif # CONFIG_DEBUG_INFO_BTF
1131endif # CONFIG_BPF
1132
1133PHONY += prepare0
1134
1135export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1136export MODORDER := $(extmod_prefix)modules.order
1137export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1138
1139ifeq ($(KBUILD_EXTMOD),)
1140core-y          += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1141
1142vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1143                     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1144                     $(libs-y) $(libs-m)))
1145
1146vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1147                     $(patsubst %/,%,$(filter %/, $(core-) \
1148                        $(drivers-) $(libs-))))
1149
1150subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1151                        $(core-y) $(core-m) $(libs-y) $(libs-m) \
1152                        $(drivers-y) $(drivers-m)))
1153
1154build-dirs      := $(vmlinux-dirs)
1155clean-dirs      := $(vmlinux-alldirs)
1156
1157# Externally visible symbols (used by link-vmlinux.sh)
1158KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1159KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1160ifdef CONFIG_MODULES
1161KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1162KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1163else
1164KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1165endif
1166KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1167
1168export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1169export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1170# used by scripts/Makefile.package
1171export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1172
1173vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1174
1175# Recurse until adjust_autoksyms.sh is satisfied
1176PHONY += autoksyms_recursive
1177ifdef CONFIG_TRIM_UNUSED_KSYMS
1178# For the kernel to actually contain only the needed exported symbols,
1179# we have to build modules as well to determine what those symbols are.
1180# (this can be evaluated only once include/config/auto.conf has been included)
1181KBUILD_MODULES := 1
1182
1183autoksyms_recursive: descend modules.order
1184        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1185          "$(MAKE) -f $(srctree)/Makefile vmlinux"
1186endif
1187
1188autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1189
1190quiet_cmd_autoksyms_h = GEN     $@
1191      cmd_autoksyms_h = mkdir -p $(dir $@); \
1192                        $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1193
1194$(autoksyms_h):
1195        $(call cmd,autoksyms_h)
1196
1197ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1198
1199# Final link of vmlinux with optional arch pass after final link
1200cmd_link-vmlinux =                                                 \
1201        $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1202        $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1203
1204vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1205        +$(call if_changed_dep,link-vmlinux)
1206
1207targets := vmlinux
1208
1209# The actual objects are generated when descending,
1210# make sure no implicit rule kicks in
1211$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1212
1213filechk_kernel.release = \
1214        echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1215
1216# Store (new) KERNELRELEASE string in include/config/kernel.release
1217include/config/kernel.release: FORCE
1218        $(call filechk,kernel.release)
1219
1220# Additional helpers built in scripts/
1221# Carefully list dependencies so we do not try to build scripts twice
1222# in parallel
1223PHONY += scripts
1224scripts: scripts_basic scripts_dtc
1225        $(Q)$(MAKE) $(build)=$(@)
1226
1227# Things we need to do before we recursively start building the kernel
1228# or the modules are listed in "prepare".
1229# A multi level approach is used. prepareN is processed before prepareN-1.
1230# archprepare is used in arch Makefiles and when processed asm symlink,
1231# version.h and scripts_basic is processed / created.
1232
1233PHONY += prepare archprepare
1234
1235archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1236        asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1237        include/generated/autoconf.h remove-stale-files
1238
1239prepare0: archprepare
1240        $(Q)$(MAKE) $(build)=scripts/mod
1241        $(Q)$(MAKE) $(build)=.
1242
1243# All the preparing..
1244prepare: prepare0 prepare-objtool prepare-resolve_btfids
1245
1246PHONY += remove-stale-files
1247remove-stale-files:
1248        $(Q)$(srctree)/scripts/remove-stale-files
1249
1250# Support for using generic headers in asm-generic
1251asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1252
1253PHONY += asm-generic uapi-asm-generic
1254asm-generic: uapi-asm-generic
1255        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1256        generic=include/asm-generic
1257uapi-asm-generic:
1258        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1259        generic=include/uapi/asm-generic
1260
1261PHONY += prepare-objtool prepare-resolve_btfids
1262prepare-objtool: $(objtool_target)
1263ifeq ($(SKIP_STACK_VALIDATION),1)
1264ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
1265        @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1266        @false
1267endif
1268ifdef CONFIG_UNWINDER_ORC
1269        @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1270        @false
1271else
1272        @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1273endif
1274endif
1275
1276prepare-resolve_btfids: $(resolve_btfids_target)
1277ifeq ($(ERROR_RESOLVE_BTFIDS),1)
1278        @echo "error: Cannot resolve BTF IDs for CONFIG_DEBUG_INFO_BTF, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1279        @false
1280endif
1281# Generate some files
1282# ---------------------------------------------------------------------------
1283
1284# KERNELRELEASE can change from a few different places, meaning version.h
1285# needs to be updated, so this check is forced on all builds
1286
1287uts_len := 64
1288define filechk_utsrelease.h
1289        if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1290          echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1291          exit 1;                                                         \
1292        fi;                                                               \
1293        echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1294endef
1295
1296define filechk_version.h
1297        if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1298                echo \#define LINUX_VERSION_CODE $(shell                 \
1299                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1300        else                                                             \
1301                echo \#define LINUX_VERSION_CODE $(shell                 \
1302                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1303        fi;                                                              \
1304        echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1305        ((c) > 255 ? 255 : (c)))';                                       \
1306        echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1307        echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1308        echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1309endef
1310
1311$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1312$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1313$(version_h): FORCE
1314        $(call filechk,version.h)
1315
1316include/generated/utsrelease.h: include/config/kernel.release FORCE
1317        $(call filechk,utsrelease.h)
1318
1319PHONY += headerdep
1320headerdep:
1321        $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1322        $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1323
1324# ---------------------------------------------------------------------------
1325# Kernel headers
1326
1327#Default location for installed headers
1328export INSTALL_HDR_PATH = $(objtree)/usr
1329
1330quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1331      cmd_headers_install = \
1332        mkdir -p $(INSTALL_HDR_PATH); \
1333        rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1334        usr/include $(INSTALL_HDR_PATH)
1335
1336PHONY += headers_install
1337headers_install: headers
1338        $(call cmd,headers_install)
1339
1340PHONY += archheaders archscripts
1341
1342hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1343
1344PHONY += headers
1345headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1346        $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1347          $(error Headers not exportable for the $(SRCARCH) architecture))
1348        $(Q)$(MAKE) $(hdr-inst)=include/uapi
1349        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1350
1351# Deprecated. It is no-op now.
1352PHONY += headers_check
1353headers_check:
1354        @echo >&2 "=================== WARNING ==================="
1355        @echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1356        @echo >&2 "and will be removed after Linux 5.15 release."
1357        @echo >&2 "Please remove headers_check from your scripts."
1358        @echo >&2 "==============================================="
1359
1360ifdef CONFIG_HEADERS_INSTALL
1361prepare: headers
1362endif
1363
1364PHONY += scripts_unifdef
1365scripts_unifdef: scripts_basic
1366        $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1367
1368# ---------------------------------------------------------------------------
1369# Install
1370
1371# Many distributions have the custom install script, /sbin/installkernel.
1372# If DKMS is installed, 'make install' will eventually recuses back
1373# to the this Makefile to build and install external modules.
1374# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1375
1376install: sub_make_done :=
1377
1378# Kernel selftest
1379
1380PHONY += kselftest
1381kselftest:
1382        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1383
1384kselftest-%: FORCE
1385        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1386
1387PHONY += kselftest-merge
1388kselftest-merge:
1389        $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1390        $(Q)find $(srctree)/tools/testing/selftests -name config | \
1391                xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1392        $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1393
1394# ---------------------------------------------------------------------------
1395# Devicetree files
1396
1397ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1398dtstree := arch/$(SRCARCH)/boot/dts
1399endif
1400
1401ifneq ($(dtstree),)
1402
1403%.dtb: include/config/kernel.release scripts_dtc
1404        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1405
1406%.dtbo: include/config/kernel.release scripts_dtc
1407        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1408
1409PHONY += dtbs dtbs_install dtbs_check
1410dtbs: include/config/kernel.release scripts_dtc
1411        $(Q)$(MAKE) $(build)=$(dtstree)
1412
1413ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1414export CHECK_DTBS=y
1415dtbs: dt_binding_check
1416endif
1417
1418dtbs_check: dtbs
1419
1420dtbs_install:
1421        $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1422
1423ifdef CONFIG_OF_EARLY_FLATTREE
1424all: dtbs
1425endif
1426
1427endif
1428
1429PHONY += scripts_dtc
1430scripts_dtc: scripts_basic
1431        $(Q)$(MAKE) $(build)=scripts/dtc
1432
1433ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1434export CHECK_DT_BINDING=y
1435endif
1436
1437PHONY += dt_binding_check
1438dt_binding_check: scripts_dtc
1439        $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1440
1441# ---------------------------------------------------------------------------
1442# Modules
1443
1444ifdef CONFIG_MODULES
1445
1446# By default, build modules as well
1447
1448all: modules
1449
1450# When we're building modules with modversions, we need to consider
1451# the built-in objects during the descend as well, in order to
1452# make sure the checksums are up to date before we record them.
1453ifdef CONFIG_MODVERSIONS
1454  KBUILD_BUILTIN := 1
1455endif
1456
1457# Build modules
1458#
1459# A module can be listed more than once in obj-m resulting in
1460# duplicate lines in modules.order files.  Those are removed
1461# using awk while concatenating to the final file.
1462
1463PHONY += modules
1464modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1465
1466cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1467
1468modules.order: $(subdir-modorder) FORCE
1469        $(call if_changed,modules_order)
1470
1471targets += modules.order
1472
1473# Target to prepare building external modules
1474PHONY += modules_prepare
1475modules_prepare: prepare
1476        $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1477
1478export modules_sign_only :=
1479
1480ifeq ($(CONFIG_MODULE_SIG),y)
1481PHONY += modules_sign
1482modules_sign: modules_install
1483        @:
1484
1485# modules_sign is a subset of modules_install.
1486# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1487ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1488modules_sign_only := y
1489endif
1490endif
1491
1492modinst_pre :=
1493ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1494modinst_pre := __modinst_pre
1495endif
1496
1497modules_install: $(modinst_pre)
1498PHONY += __modinst_pre
1499__modinst_pre:
1500        @rm -rf $(MODLIB)/kernel
1501        @rm -f $(MODLIB)/source
1502        @mkdir -p $(MODLIB)/kernel
1503        @ln -s $(abspath $(srctree)) $(MODLIB)/source
1504        @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1505                rm -f $(MODLIB)/build ; \
1506                ln -s $(CURDIR) $(MODLIB)/build ; \
1507        fi
1508        @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1509        @cp -f modules.builtin $(MODLIB)/
1510        @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1511
1512endif # CONFIG_MODULES
1513
1514###
1515# Cleaning is done on three levels.
1516# make clean     Delete most generated files
1517#                Leave enough to build external modules
1518# make mrproper  Delete the current configuration, and all generated files
1519# make distclean Remove editor backup files, patch leftover files and the like
1520
1521# Directories & files removed with 'make clean'
1522CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1523               modules.builtin modules.builtin.modinfo modules.nsdeps \
1524               compile_commands.json .thinlto-cache
1525
1526# Directories & files removed with 'make mrproper'
1527MRPROPER_FILES += include/config include/generated          \
1528                  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1529                  debian snap tar-install \
1530                  .config .config.old .version \
1531                  Module.symvers \
1532                  certs/signing_key.pem certs/signing_key.x509 \
1533                  certs/x509.genkey \
1534                  vmlinux-gdb.py \
1535                  *.spec
1536
1537# clean - Delete most, but leave enough to build external modules
1538#
1539clean: rm-files := $(CLEAN_FILES)
1540
1541PHONY += archclean vmlinuxclean
1542
1543vmlinuxclean:
1544        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1545        $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1546
1547clean: archclean vmlinuxclean resolve_btfids_clean
1548
1549# mrproper - Delete all generated files, including .config
1550#
1551mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1552mrproper-dirs      := $(addprefix _mrproper_,scripts)
1553
1554PHONY += $(mrproper-dirs) mrproper
1555$(mrproper-dirs):
1556        $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1557
1558mrproper: clean $(mrproper-dirs)
1559        $(call cmd,rmfiles)
1560
1561# distclean
1562#
1563PHONY += distclean
1564
1565distclean: mrproper
1566        @find . $(RCS_FIND_IGNORE) \
1567                \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1568                -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1569                -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1570                -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1571                -type f -print | xargs rm -f
1572
1573
1574# Packaging of the kernel to various formats
1575# ---------------------------------------------------------------------------
1576
1577%src-pkg: FORCE
1578        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1579%pkg: include/config/kernel.release FORCE
1580        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1581
1582# Brief documentation of the typical targets used
1583# ---------------------------------------------------------------------------
1584
1585boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1586boards := $(sort $(notdir $(boards)))
1587board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1588board-dirs := $(sort $(notdir $(board-dirs:/=)))
1589
1590PHONY += help
1591help:
1592        @echo  'Cleaning targets:'
1593        @echo  '  clean           - Remove most generated files but keep the config and'
1594        @echo  '                    enough build support to build external modules'
1595        @echo  '  mrproper        - Remove all generated files + config + various backup files'
1596        @echo  '  distclean       - mrproper + remove editor backup and patch files'
1597        @echo  ''
1598        @echo  'Configuration targets:'
1599        @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1600        @echo  ''
1601        @echo  'Other generic targets:'
1602        @echo  '  all             - Build all targets marked with [*]'
1603        @echo  '* vmlinux         - Build the bare kernel'
1604        @echo  '* modules         - Build all modules'
1605        @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1606        @echo  '  dir/            - Build all files in dir and below'
1607        @echo  '  dir/file.[ois]  - Build specified target only'
1608        @echo  '  dir/file.ll     - Build the LLVM assembly file'
1609        @echo  '                    (requires compiler support for LLVM assembly generation)'
1610        @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1611        @echo  '                    (requires a recent binutils and recent build (System.map))'
1612        @echo  '  dir/file.ko     - Build module including final link'
1613        @echo  '  modules_prepare - Set up for building external modules'
1614        @echo  '  tags/TAGS       - Generate tags file for editors'
1615        @echo  '  cscope          - Generate cscope index'
1616        @echo  '  gtags           - Generate GNU GLOBAL index'
1617        @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1618        @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1619        @echo  '  image_name      - Output the image name (use with make -s)'
1620        @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1621         echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1622         echo  ''
1623        @echo  'Static analysers:'
1624        @echo  '  checkstack      - Generate a list of stack hogs'
1625        @echo  '  versioncheck    - Sanity check on version.h usage'
1626        @echo  '  includecheck    - Check for duplicate included header files'
1627        @echo  '  export_report   - List the usages of all exported symbols'
1628        @echo  '  headerdep       - Detect inclusion cycles in headers'
1629        @echo  '  coccicheck      - Check with Coccinelle'
1630        @echo  '  clang-analyzer  - Check with clang static analyzer'
1631        @echo  '  clang-tidy      - Check with clang-tidy'
1632        @echo  ''
1633        @echo  'Tools:'
1634        @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1635        @echo  ''
1636        @echo  'Kernel selftest:'
1637        @echo  '  kselftest         - Build and run kernel selftest'
1638        @echo  '                      Build, install, and boot kernel before'
1639        @echo  '                      running kselftest on it'
1640        @echo  '                      Run as root for full coverage'
1641        @echo  '  kselftest-all     - Build kernel selftest'
1642        @echo  '  kselftest-install - Build and install kernel selftest'
1643        @echo  '  kselftest-clean   - Remove all generated kselftest files'
1644        @echo  '  kselftest-merge   - Merge all the config dependencies of'
1645        @echo  '                      kselftest to existing .config.'
1646        @echo  ''
1647        @$(if $(dtstree), \
1648                echo 'Devicetree:'; \
1649                echo '* dtbs             - Build device tree blobs for enabled boards'; \
1650                echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1651                echo '  dt_binding_check - Validate device tree binding documents'; \
1652                echo '  dtbs_check       - Validate device tree source files';\
1653                echo '')
1654
1655        @echo 'Userspace tools targets:'
1656        @echo '  use "make tools/help"'
1657        @echo '  or  "cd tools; make help"'
1658        @echo  ''
1659        @echo  'Kernel packaging:'
1660        @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1661        @echo  ''
1662        @echo  'Documentation targets:'
1663        @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1664        @echo  ''
1665        @echo  'Architecture specific targets ($(SRCARCH)):'
1666        @$(if $(archhelp),$(archhelp),\
1667                echo '  No architecture specific help defined for $(SRCARCH)')
1668        @echo  ''
1669        @$(if $(boards), \
1670                $(foreach b, $(boards), \
1671                printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1672                echo '')
1673        @$(if $(board-dirs), \
1674                $(foreach b, $(board-dirs), \
1675                printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1676                printf "  %-16s - Show all of the above\\n" help-boards; \
1677                echo '')
1678
1679        @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1680        @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1681        @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1682        @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1683        @echo  '                       (sparse by default)'
1684        @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1685        @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1686        @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1687        @echo  '                1: warnings which may be relevant and do not occur too often'
1688        @echo  '                2: warnings which occur quite often but may still be relevant'
1689        @echo  '                3: more obscure warnings, can most likely be ignored'
1690        @echo  '                Multiple levels can be combined with W=12 or W=123'
1691        @echo  ''
1692        @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1693        @echo  'For further info see the ./README file'
1694
1695
1696help-board-dirs := $(addprefix help-,$(board-dirs))
1697
1698help-boards: $(help-board-dirs)
1699
1700boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1701
1702$(help-board-dirs): help-%:
1703        @echo  'Architecture specific targets ($(SRCARCH) $*):'
1704        @$(if $(boards-per-dir), \
1705                $(foreach b, $(boards-per-dir), \
1706                printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1707                echo '')
1708
1709
1710# Documentation targets
1711# ---------------------------------------------------------------------------
1712DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1713               linkcheckdocs dochelp refcheckdocs
1714PHONY += $(DOC_TARGETS)
1715$(DOC_TARGETS):
1716        $(Q)$(MAKE) $(build)=Documentation $@
1717
1718# Misc
1719# ---------------------------------------------------------------------------
1720
1721PHONY += scripts_gdb
1722scripts_gdb: prepare0
1723        $(Q)$(MAKE) $(build)=scripts/gdb
1724        $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1725
1726ifdef CONFIG_GDB_SCRIPTS
1727all: scripts_gdb
1728endif
1729
1730else # KBUILD_EXTMOD
1731
1732###
1733# External module support.
1734# When building external modules the kernel used as basis is considered
1735# read-only, and no consistency checks are made and the make
1736# system is not used on the basis kernel. If updates are required
1737# in the basis kernel ordinary make commands (without M=...) must be used.
1738
1739# We are always building only modules.
1740KBUILD_BUILTIN :=
1741KBUILD_MODULES := 1
1742
1743build-dirs := $(KBUILD_EXTMOD)
1744$(MODORDER): descend
1745        @:
1746
1747compile_commands.json: $(extmod_prefix)compile_commands.json
1748PHONY += compile_commands.json
1749
1750clean-dirs := $(KBUILD_EXTMOD)
1751clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1752        $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1753
1754PHONY += help
1755help:
1756        @echo  '  Building external modules.'
1757        @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1758        @echo  ''
1759        @echo  '  modules         - default target, build the module(s)'
1760        @echo  '  modules_install - install the module'
1761        @echo  '  clean           - remove generated files in module directory only'
1762        @echo  ''
1763
1764# no-op for external module builds
1765PHONY += prepare modules_prepare
1766
1767endif # KBUILD_EXTMOD
1768
1769# ---------------------------------------------------------------------------
1770# Modules
1771
1772PHONY += modules modules_install
1773
1774ifdef CONFIG_MODULES
1775
1776modules: modules_check
1777        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1778
1779PHONY += modules_check
1780modules_check: $(MODORDER)
1781        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1782
1783quiet_cmd_depmod = DEPMOD  $(MODLIB)
1784      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1785                   $(KERNELRELEASE)
1786
1787modules_install:
1788        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1789        $(call cmd,depmod)
1790
1791else # CONFIG_MODULES
1792
1793# Modules not configured
1794# ---------------------------------------------------------------------------
1795
1796modules modules_install:
1797        @echo >&2 '***'
1798        @echo >&2 '*** The present kernel configuration has modules disabled.'
1799        @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1800        @echo >&2 '*** to enable CONFIG_MODULES.'
1801        @echo >&2 '***'
1802        @exit 1
1803
1804endif # CONFIG_MODULES
1805
1806# Single targets
1807# ---------------------------------------------------------------------------
1808# To build individual files in subdirectories, you can do like this:
1809#
1810#   make foo/bar/baz.s
1811#
1812# The supported suffixes for single-target are listed in 'single-targets'
1813#
1814# To build only under specific subdirectories, you can do like this:
1815#
1816#   make foo/bar/baz/
1817
1818ifdef single-build
1819
1820# .ko is special because modpost is needed
1821single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1822single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1823
1824$(single-ko): single_modpost
1825        @:
1826$(single-no-ko): descend
1827        @:
1828
1829ifeq ($(KBUILD_EXTMOD),)
1830# For the single build of in-tree modules, use a temporary file to avoid
1831# the situation of modules_install installing an invalid modules.order.
1832MODORDER := .modules.tmp
1833endif
1834
1835PHONY += single_modpost
1836single_modpost: $(single-no-ko) modules_prepare
1837        $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1838        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1839
1840KBUILD_MODULES := 1
1841
1842export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1843
1844# trim unrelated directories
1845build-dirs := $(foreach d, $(build-dirs), \
1846                        $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1847
1848endif
1849
1850ifndef CONFIG_MODULES
1851KBUILD_MODULES :=
1852endif
1853
1854# Handle descending into subdirectories listed in $(build-dirs)
1855# Preset locale variables to speed up the build process. Limit locale
1856# tweaks to this spot to avoid wrong language settings when running
1857# make menuconfig etc.
1858# Error messages still appears in the original language
1859PHONY += descend $(build-dirs)
1860descend: $(build-dirs)
1861$(build-dirs): prepare
1862        $(Q)$(MAKE) $(build)=$@ \
1863        single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1864        need-builtin=1 need-modorder=1
1865
1866clean-dirs := $(addprefix _clean_, $(clean-dirs))
1867PHONY += $(clean-dirs) clean
1868$(clean-dirs):
1869        $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1870
1871clean: $(clean-dirs)
1872        $(call cmd,rmfiles)
1873        @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1874                \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1875                -o -name '*.ko.*' \
1876                -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1877                -o -name '*.dwo' -o -name '*.lst' \
1878                -o -name '*.su' -o -name '*.mod' \
1879                -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1880                -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1881                -o -name '*.asn1.[ch]' \
1882                -o -name '*.symtypes' -o -name 'modules.order' \
1883                -o -name '.tmp_*.o.*' \
1884                -o -name '*.c.[012]*.*' \
1885                -o -name '*.ll' \
1886                -o -name '*.gcno' \
1887                -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1888
1889# Generate tags for editors
1890# ---------------------------------------------------------------------------
1891quiet_cmd_tags = GEN     $@
1892      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1893
1894tags TAGS cscope gtags: FORCE
1895        $(call cmd,tags)
1896
1897# Script to generate missing namespace dependencies
1898# ---------------------------------------------------------------------------
1899
1900PHONY += nsdeps
1901nsdeps: export KBUILD_NSDEPS=1
1902nsdeps: modules
1903        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1904
1905# Clang Tooling
1906# ---------------------------------------------------------------------------
1907
1908quiet_cmd_gen_compile_commands = GEN     $@
1909      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1910
1911$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1912        $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1913        $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1914        $(call if_changed,gen_compile_commands)
1915
1916targets += $(extmod_prefix)compile_commands.json
1917
1918PHONY += clang-tidy clang-analyzer
1919
1920ifdef CONFIG_CC_IS_CLANG
1921quiet_cmd_clang_tools = CHECK   $<
1922      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1923
1924clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1925        $(call cmd,clang_tools)
1926else
1927clang-tidy clang-analyzer:
1928        @echo "$@ requires CC=clang" >&2
1929        @false
1930endif
1931
1932# Scripts to check various things for consistency
1933# ---------------------------------------------------------------------------
1934
1935PHONY += includecheck versioncheck coccicheck export_report
1936
1937includecheck:
1938        find $(srctree)/* $(RCS_FIND_IGNORE) \
1939                -name '*.[hcS]' -type f -print | sort \
1940                | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1941
1942versioncheck:
1943        find $(srctree)/* $(RCS_FIND_IGNORE) \
1944                -name '*.[hcS]' -type f -print | sort \
1945                | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1946
1947coccicheck:
1948        $(Q)$(BASH) $(srctree)/scripts/$@
1949
1950export_report:
1951        $(PERL) $(srctree)/scripts/export_report.pl
1952
1953PHONY += checkstack kernelrelease kernelversion image_name
1954
1955# UML needs a little special treatment here.  It wants to use the host
1956# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1957# else wants $(ARCH), including people doing cross-builds, which means
1958# that $(SUBARCH) doesn't work here.
1959ifeq ($(ARCH), um)
1960CHECKSTACK_ARCH := $(SUBARCH)
1961else
1962CHECKSTACK_ARCH := $(ARCH)
1963endif
1964checkstack:
1965        $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1966        $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1967
1968kernelrelease:
1969        @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1970
1971kernelversion:
1972        @echo $(KERNELVERSION)
1973
1974image_name:
1975        @echo $(KBUILD_IMAGE)
1976
1977# Clear a bunch of variables before executing the submake
1978
1979ifeq ($(quiet),silent_)
1980tools_silent=s
1981endif
1982
1983tools/: FORCE
1984        $(Q)mkdir -p $(objtree)/tools
1985        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1986
1987tools/%: FORCE
1988        $(Q)mkdir -p $(objtree)/tools
1989        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1990
1991quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1992      cmd_rmfiles = rm -rf $(rm-files)
1993
1994# read saved command lines for existing targets
1995existing-targets := $(wildcard $(sort $(targets)))
1996
1997-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1998
1999endif # config-build
2000endif # mixed-build
2001endif # need-sub-make
2002
2003PHONY += FORCE
2004FORCE:
2005
2006# Declare the contents of the PHONY variable as phony.  We keep that
2007# information in a variable so we can use it in if_changed and friends.
2008.PHONY: $(PHONY)
2009