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   1# SPDX-License-Identifier: GPL-2.0
   2VERSION = 5
   3PATCHLEVEL = 14
   4SUBLEVEL = 6
   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 ($(ARCH),sparc64)
 404       SRCARCH := sparc
 405endif
 406
 407# Additional ARCH settings for parisc
 408ifeq ($(ARCH),parisc64)
 409       SRCARCH := parisc
 410endif
 411
 412export cross_compiling :=
 413ifneq ($(SRCARCH),$(SUBARCH))
 414cross_compiling := 1
 415endif
 416
 417KCONFIG_CONFIG  ?= .config
 418export KCONFIG_CONFIG
 419
 420# SHELL used by kbuild
 421CONFIG_SHELL := sh
 422
 423HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 424HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 425HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 426
 427ifneq ($(LLVM),)
 428HOSTCC  = clang
 429HOSTCXX = clang++
 430else
 431HOSTCC  = gcc
 432HOSTCXX = g++
 433endif
 434
 435export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 436                              -O2 -fomit-frame-pointer -std=gnu89
 437export KBUILD_USERLDFLAGS :=
 438
 439KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 440KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 441KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 442KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 443
 444# Make variables (CC, etc...)
 445CPP             = $(CC) -E
 446ifneq ($(LLVM),)
 447CC              = clang
 448LD              = ld.lld
 449AR              = llvm-ar
 450NM              = llvm-nm
 451OBJCOPY         = llvm-objcopy
 452OBJDUMP         = llvm-objdump
 453READELF         = llvm-readelf
 454STRIP           = llvm-strip
 455else
 456CC              = $(CROSS_COMPILE)gcc
 457LD              = $(CROSS_COMPILE)ld
 458AR              = $(CROSS_COMPILE)ar
 459NM              = $(CROSS_COMPILE)nm
 460OBJCOPY         = $(CROSS_COMPILE)objcopy
 461OBJDUMP         = $(CROSS_COMPILE)objdump
 462READELF         = $(CROSS_COMPILE)readelf
 463STRIP           = $(CROSS_COMPILE)strip
 464endif
 465PAHOLE          = pahole
 466RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 467LEX             = flex
 468YACC            = bison
 469AWK             = awk
 470INSTALLKERNEL  := installkernel
 471DEPMOD          = depmod
 472PERL            = perl
 473PYTHON3         = python3
 474CHECK           = sparse
 475BASH            = bash
 476KGZIP           = gzip
 477KBZIP2          = bzip2
 478KLZOP           = lzop
 479LZMA            = lzma
 480LZ4             = lz4c
 481XZ              = xz
 482ZSTD            = zstd
 483
 484CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 485                  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 486NOSTDINC_FLAGS :=
 487CFLAGS_MODULE   =
 488AFLAGS_MODULE   =
 489LDFLAGS_MODULE  =
 490CFLAGS_KERNEL   =
 491AFLAGS_KERNEL   =
 492LDFLAGS_vmlinux =
 493
 494# Use USERINCLUDE when you must reference the UAPI directories only.
 495USERINCLUDE    := \
 496                -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 497                -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 498                -I$(srctree)/include/uapi \
 499                -I$(objtree)/include/generated/uapi \
 500                -include $(srctree)/include/linux/compiler-version.h \
 501                -include $(srctree)/include/linux/kconfig.h
 502
 503# Use LINUXINCLUDE when you must reference the include/ directory.
 504# Needed to be compatible with the O= option
 505LINUXINCLUDE    := \
 506                -I$(srctree)/arch/$(SRCARCH)/include \
 507                -I$(objtree)/arch/$(SRCARCH)/include/generated \
 508                $(if $(building_out_of_srctree),-I$(srctree)/include) \
 509                -I$(objtree)/include \
 510                $(USERINCLUDE)
 511
 512KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 513KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 514                   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 515                   -Werror=implicit-function-declaration -Werror=implicit-int \
 516                   -Werror=return-type -Wno-format-security \
 517                   -std=gnu89
 518KBUILD_CPPFLAGS := -D__KERNEL__
 519KBUILD_AFLAGS_KERNEL :=
 520KBUILD_CFLAGS_KERNEL :=
 521KBUILD_AFLAGS_MODULE  := -DMODULE
 522KBUILD_CFLAGS_MODULE  := -DMODULE
 523KBUILD_LDFLAGS_MODULE :=
 524KBUILD_LDFLAGS :=
 525CLANG_FLAGS :=
 526
 527export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
 528export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 529export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 530export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 531export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 532
 533export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 534export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 535export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 536export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 537export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 538
 539# Files to ignore in find ... statements
 540
 541export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 542                          -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 543                          -prune -o
 544export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 545                         --exclude CVS --exclude .pc --exclude .hg --exclude .git
 546
 547# ===========================================================================
 548# Rules shared between *config targets and build targets
 549
 550# Basic helpers built in scripts/basic/
 551PHONY += scripts_basic
 552scripts_basic:
 553        $(Q)$(MAKE) $(build)=scripts/basic
 554
 555PHONY += outputmakefile
 556ifdef building_out_of_srctree
 557# Before starting out-of-tree build, make sure the source tree is clean.
 558# outputmakefile generates a Makefile in the output directory, if using a
 559# separate output directory. This allows convenient use of make in the
 560# output directory.
 561# At the same time when output Makefile generated, generate .gitignore to
 562# ignore whole output directory
 563
 564quiet_cmd_makefile = GEN     Makefile
 565      cmd_makefile = { \
 566        echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
 567        echo "include $(srctree)/Makefile"; \
 568        } > Makefile
 569
 570outputmakefile:
 571        $(Q)if [ -f $(srctree)/.config -o \
 572                 -d $(srctree)/include/config -o \
 573                 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 574                echo >&2 "***"; \
 575                echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 576                echo >&2 "*** in $(abs_srctree)";\
 577                echo >&2 "***"; \
 578                false; \
 579        fi
 580        $(Q)ln -fsn $(srctree) source
 581        $(call cmd,makefile)
 582        $(Q)test -e .gitignore || \
 583        { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 584endif
 585
 586# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 587# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 588# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 589# and from include/config/auto.conf.cmd to detect the compiler upgrade.
 590CC_VERSION_TEXT = $(subst $(pound),,$(shell $(CC) --version 2>/dev/null | head -n 1))
 591
 592ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 593ifneq ($(CROSS_COMPILE),)
 594CLANG_FLAGS     += --target=$(notdir $(CROSS_COMPILE:%-=%))
 595endif
 596ifeq ($(LLVM_IAS),1)
 597CLANG_FLAGS     += -integrated-as
 598else
 599CLANG_FLAGS     += -no-integrated-as
 600GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
 601CLANG_FLAGS     += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
 602endif
 603CLANG_FLAGS     += -Werror=unknown-warning-option
 604KBUILD_CFLAGS   += $(CLANG_FLAGS)
 605KBUILD_AFLAGS   += $(CLANG_FLAGS)
 606export CLANG_FLAGS
 607endif
 608
 609# Include this also for config targets because some architectures need
 610# cc-cross-prefix to determine CROSS_COMPILE.
 611ifdef need-compiler
 612include $(srctree)/scripts/Makefile.compiler
 613endif
 614
 615ifdef config-build
 616# ===========================================================================
 617# *config targets only - make sure prerequisites are updated, and descend
 618# in scripts/kconfig to make the *config target
 619
 620# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 621# KBUILD_DEFCONFIG may point out an alternative default configuration
 622# used for 'make defconfig'
 623include $(srctree)/arch/$(SRCARCH)/Makefile
 624export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 625
 626config: outputmakefile scripts_basic FORCE
 627        $(Q)$(MAKE) $(build)=scripts/kconfig $@
 628
 629%config: outputmakefile scripts_basic FORCE
 630        $(Q)$(MAKE) $(build)=scripts/kconfig $@
 631
 632else #!config-build
 633# ===========================================================================
 634# Build targets only - this includes vmlinux, arch specific targets, clean
 635# targets and others. In general all targets except *config targets.
 636
 637# If building an external module we do not care about the all: rule
 638# but instead __all depend on modules
 639PHONY += all
 640ifeq ($(KBUILD_EXTMOD),)
 641__all: all
 642else
 643__all: modules
 644endif
 645
 646# Decide whether to build built-in, modular, or both.
 647# Normally, just do built-in.
 648
 649KBUILD_MODULES :=
 650KBUILD_BUILTIN := 1
 651
 652# If we have only "make modules", don't compile built-in objects.
 653ifeq ($(MAKECMDGOALS),modules)
 654  KBUILD_BUILTIN :=
 655endif
 656
 657# If we have "make <whatever> modules", compile modules
 658# in addition to whatever we do anyway.
 659# Just "make" or "make all" shall build modules as well
 660
 661ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 662  KBUILD_MODULES := 1
 663endif
 664
 665ifeq ($(MAKECMDGOALS),)
 666  KBUILD_MODULES := 1
 667endif
 668
 669export KBUILD_MODULES KBUILD_BUILTIN
 670
 671ifdef need-config
 672include include/config/auto.conf
 673endif
 674
 675ifeq ($(KBUILD_EXTMOD),)
 676# Objects we will link into vmlinux / subdirs we need to visit
 677core-y          := init/ usr/ arch/$(SRCARCH)/
 678drivers-y       := drivers/ sound/
 679drivers-$(CONFIG_SAMPLES) += samples/
 680drivers-$(CONFIG_NET) += net/
 681drivers-y       += virt/
 682libs-y          := lib/
 683endif # KBUILD_EXTMOD
 684
 685# The all: target is the default when no target is given on the
 686# command line.
 687# This allow a user to issue only 'make' to build a kernel including modules
 688# Defaults to vmlinux, but the arch makefile usually adds further targets
 689all: vmlinux
 690
 691CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage \
 692        $(call cc-option,-fno-tree-loop-im) \
 693        $(call cc-disable-warning,maybe-uninitialized,)
 694export CFLAGS_GCOV
 695
 696# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 697ifdef CONFIG_FUNCTION_TRACER
 698  CC_FLAGS_FTRACE := -pg
 699endif
 700
 701RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
 702RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
 703RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
 704RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
 705RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
 706RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
 707export RETPOLINE_CFLAGS
 708export RETPOLINE_VDSO_CFLAGS
 709
 710include $(srctree)/arch/$(SRCARCH)/Makefile
 711
 712ifdef need-config
 713ifdef may-sync-config
 714# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 715# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 716# because some architectures define CROSS_COMPILE there.
 717include include/config/auto.conf.cmd
 718
 719$(KCONFIG_CONFIG):
 720        @echo >&2 '***'
 721        @echo >&2 '*** Configuration file "$@" not found!'
 722        @echo >&2 '***'
 723        @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 724        @echo >&2 '*** "make menuconfig" or "make xconfig").'
 725        @echo >&2 '***'
 726        @/bin/false
 727
 728# The actual configuration files used during the build are stored in
 729# include/generated/ and include/config/. Update them if .config is newer than
 730# include/config/auto.conf (which mirrors .config).
 731#
 732# This exploits the 'multi-target pattern rule' trick.
 733# The syncconfig should be executed only once to make all the targets.
 734# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 735#
 736# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
 737# so you cannot notice that Kconfig is waiting for the user input.
 738%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 739        $(Q)$(kecho) "  SYNC    $@"
 740        $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
 741else # !may-sync-config
 742# External modules and some install targets need include/generated/autoconf.h
 743# and include/config/auto.conf but do not care if they are up-to-date.
 744# Use auto.conf to trigger the test
 745PHONY += include/config/auto.conf
 746
 747include/config/auto.conf:
 748        $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 749        echo >&2;                                                       \
 750        echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 751        echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 752        echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 753        echo >&2 ;                                                      \
 754        /bin/false)
 755
 756endif # may-sync-config
 757endif # need-config
 758
 759KBUILD_CFLAGS   += $(call cc-option,-fno-delete-null-pointer-checks,)
 760KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 761KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 762KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 763KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 764
 765ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 766KBUILD_CFLAGS += -O2
 767else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
 768KBUILD_CFLAGS += -O3
 769else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 770KBUILD_CFLAGS += -Os
 771endif
 772
 773# Tell gcc to never replace conditional load with a non-conditional one
 774KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 775KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 776
 777ifdef CONFIG_READABLE_ASM
 778# Disable optimizations that make assembler listings hard to read.
 779# reorder blocks reorders the control in the function
 780# ipa clone creates specialized cloned functions
 781# partial inlining inlines only parts of functions
 782KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
 783                 $(call cc-option,-fno-ipa-cp-clone,) \
 784                 $(call cc-option,-fno-partial-inlining)
 785endif
 786
 787ifneq ($(CONFIG_FRAME_WARN),0)
 788KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 789endif
 790
 791stackp-flags-y                                    := -fno-stack-protector
 792stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 793stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 794
 795KBUILD_CFLAGS += $(stackp-flags-y)
 796
 797ifdef CONFIG_CC_IS_CLANG
 798KBUILD_CPPFLAGS += -Qunused-arguments
 799KBUILD_CFLAGS += -Wno-format-invalid-specifier
 800KBUILD_CFLAGS += -Wno-gnu
 801# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 802# source of a reference will be _MergedGlobals and not on of the whitelisted names.
 803# See modpost pattern 2
 804KBUILD_CFLAGS += -mno-global-merge
 805else
 806
 807# Warn about unmarked fall-throughs in switch statement.
 808# Disabled for clang while comment to attribute conversion happens and
 809# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
 810KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,)
 811# gcc inanely warns about local variables called 'main'
 812KBUILD_CFLAGS += -Wno-main
 813endif
 814
 815# These warnings generated too much noise in a regular build.
 816# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 817KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 818
 819KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 820ifdef CONFIG_FRAME_POINTER
 821KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 822else
 823# Some targets (ARM with Thumb2, for example), can't be built with frame
 824# pointers.  For those, we don't have FUNCTION_TRACER automatically
 825# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 826# incompatible with -fomit-frame-pointer with current GCC, so we don't use
 827# -fomit-frame-pointer with FUNCTION_TRACER.
 828ifndef CONFIG_FUNCTION_TRACER
 829KBUILD_CFLAGS   += -fomit-frame-pointer
 830endif
 831endif
 832
 833# Initialize all stack variables with a 0xAA pattern.
 834ifdef CONFIG_INIT_STACK_ALL_PATTERN
 835KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 836endif
 837
 838# Initialize all stack variables with a zero value.
 839ifdef CONFIG_INIT_STACK_ALL_ZERO
 840# Future support for zero initialization is still being debated, see
 841# https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
 842# renamed or dropped.
 843KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 844KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 845endif
 846
 847# While VLAs have been removed, GCC produces unreachable stack probes
 848# for the randomize_kstack_offset feature. Disable it for all compilers.
 849KBUILD_CFLAGS   += $(call cc-option, -fno-stack-clash-protection)
 850
 851DEBUG_CFLAGS    :=
 852
 853# Workaround for GCC versions < 5.0
 854# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
 855ifdef CONFIG_CC_IS_GCC
 856DEBUG_CFLAGS    += $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
 857endif
 858
 859ifdef CONFIG_DEBUG_INFO
 860
 861ifdef CONFIG_DEBUG_INFO_SPLIT
 862DEBUG_CFLAGS    += -gsplit-dwarf
 863else
 864DEBUG_CFLAGS    += -g
 865endif
 866
 867ifneq ($(LLVM_IAS),1)
 868KBUILD_AFLAGS   += -Wa,-gdwarf-2
 869endif
 870
 871ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
 872dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
 873dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
 874DEBUG_CFLAGS    += -gdwarf-$(dwarf-version-y)
 875endif
 876
 877ifdef CONFIG_DEBUG_INFO_REDUCED
 878DEBUG_CFLAGS    += $(call cc-option, -femit-struct-debug-baseonly) \
 879                   $(call cc-option,-fno-var-tracking)
 880endif
 881
 882ifdef CONFIG_DEBUG_INFO_COMPRESSED
 883DEBUG_CFLAGS    += -gz=zlib
 884KBUILD_AFLAGS   += -gz=zlib
 885KBUILD_LDFLAGS  += --compress-debug-sections=zlib
 886endif
 887
 888endif # CONFIG_DEBUG_INFO
 889
 890KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 891export DEBUG_CFLAGS
 892
 893ifdef CONFIG_FUNCTION_TRACER
 894ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 895  CC_FLAGS_FTRACE       += -mrecord-mcount
 896  ifdef CONFIG_HAVE_NOP_MCOUNT
 897    ifeq ($(call cc-option-yn, -mnop-mcount),y)
 898      CC_FLAGS_FTRACE   += -mnop-mcount
 899      CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 900    endif
 901  endif
 902endif
 903ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 904  CC_FLAGS_USING        += -DCC_USING_NOP_MCOUNT
 905endif
 906ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 907  ifdef CONFIG_HAVE_C_RECORDMCOUNT
 908    BUILD_C_RECORDMCOUNT := y
 909    export BUILD_C_RECORDMCOUNT
 910  endif
 911endif
 912ifdef CONFIG_HAVE_FENTRY
 913  ifeq ($(call cc-option-yn, -mfentry),y)
 914    CC_FLAGS_FTRACE     += -mfentry
 915    CC_FLAGS_USING      += -DCC_USING_FENTRY
 916  endif
 917endif
 918export CC_FLAGS_FTRACE
 919KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 920KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 921endif
 922
 923# We trigger additional mismatches with less inlining
 924ifdef CONFIG_DEBUG_SECTION_MISMATCH
 925KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
 926endif
 927
 928ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 929KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 930LDFLAGS_vmlinux += --gc-sections
 931endif
 932
 933ifdef CONFIG_SHADOW_CALL_STACK
 934CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 935KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 936export CC_FLAGS_SCS
 937endif
 938
 939ifdef CONFIG_LTO_CLANG
 940ifdef CONFIG_LTO_CLANG_THIN
 941CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 942KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
 943else
 944CC_FLAGS_LTO    := -flto
 945endif
 946CC_FLAGS_LTO    += -fvisibility=hidden
 947
 948# Limit inlining across translation units to reduce binary size
 949KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 950
 951# Check for frame size exceeding threshold during prolog/epilog insertion
 952# when using lld < 13.0.0.
 953ifneq ($(CONFIG_FRAME_WARN),0)
 954ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
 955KBUILD_LDFLAGS  += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 956endif
 957endif
 958endif
 959
 960ifdef CONFIG_LTO
 961KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 962KBUILD_AFLAGS   += -fno-lto
 963export CC_FLAGS_LTO
 964endif
 965
 966ifdef CONFIG_CFI_CLANG
 967CC_FLAGS_CFI    := -fsanitize=cfi \
 968                   -fsanitize-cfi-cross-dso \
 969                   -fno-sanitize-cfi-canonical-jump-tables \
 970                   -fno-sanitize-trap=cfi \
 971                   -fno-sanitize-blacklist
 972
 973ifdef CONFIG_CFI_PERMISSIVE
 974CC_FLAGS_CFI    += -fsanitize-recover=cfi
 975endif
 976
 977# If LTO flags are filtered out, we must also filter out CFI.
 978CC_FLAGS_LTO    += $(CC_FLAGS_CFI)
 979KBUILD_CFLAGS   += $(CC_FLAGS_CFI)
 980export CC_FLAGS_CFI
 981endif
 982
 983ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
 984KBUILD_CFLAGS += -falign-functions=64
 985endif
 986
 987# arch Makefile may override CC so keep this after arch Makefile is included
 988NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
 989
 990# warn about C99 declaration after statement
 991KBUILD_CFLAGS += -Wdeclaration-after-statement
 992
 993# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 994KBUILD_CFLAGS += -Wvla
 995
 996# disable pointer signed / unsigned warnings in gcc 4.0
 997KBUILD_CFLAGS += -Wno-pointer-sign
 998
 999# disable stringop warnings in gcc 8+
1000KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1001
1002# We'll want to enable this eventually, but it's not going away for 5.7 at least
1003KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
1004KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
1005KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1006
1007# Another good warning that we'll want to enable eventually
1008KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1009
1010# Enabled with W=2, disabled by default as noisy
1011KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
1012
1013# disable invalid "can't wrap" optimizations for signed / pointers
1014KBUILD_CFLAGS   += -fno-strict-overflow
1015
1016# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1017KBUILD_CFLAGS  += -fno-stack-check
1018
1019# conserve stack if available
1020KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
1021
1022# Prohibit date/time macros, which would make the build non-deterministic
1023KBUILD_CFLAGS   += -Werror=date-time
1024
1025# enforce correct pointer usage
1026KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1027
1028# Require designated initializers for all marked structures
1029KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1030
1031# change __FILE__ to the relative path from the srctree
1032KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1033
1034# include additional Makefiles when needed
1035include-y                       := scripts/Makefile.extrawarn
1036include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
1037include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
1038include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
1039include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
1040include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
1041
1042include $(addprefix $(srctree)/, $(include-y))
1043
1044# scripts/Makefile.gcc-plugins is intentionally included last.
1045# Do not add $(call cc-option,...) below this line. When you build the kernel
1046# from the clean source tree, the GCC plugins do not exist at this point.
1047
1048# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1049KBUILD_CPPFLAGS += $(KCPPFLAGS)
1050KBUILD_AFLAGS   += $(KAFLAGS)
1051KBUILD_CFLAGS   += $(KCFLAGS)
1052
1053KBUILD_LDFLAGS_MODULE += --build-id=sha1
1054LDFLAGS_vmlinux += --build-id=sha1
1055
1056ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1057LDFLAGS_vmlinux += $(call ld-option, -X,)
1058endif
1059
1060ifeq ($(CONFIG_RELR),y)
1061LDFLAGS_vmlinux += --pack-dyn-relocs=relr --use-android-relr-tags
1062endif
1063
1064# We never want expected sections to be placed heuristically by the
1065# linker. All sections should be explicitly named in the linker script.
1066ifdef CONFIG_LD_ORPHAN_WARN
1067LDFLAGS_vmlinux += --orphan-handling=warn
1068endif
1069
1070# Align the bit size of userspace programs with the kernel
1071KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1072KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1073
1074# make the checker run with the right architecture
1075CHECKFLAGS += --arch=$(ARCH)
1076
1077# insure the checker run with the right endianness
1078CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1079
1080# the checker needs the correct machine size
1081CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1082
1083# Default kernel image to build when no specific target is given.
1084# KBUILD_IMAGE may be overruled on the command line or
1085# set in the environment
1086# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1087# this default value
1088export KBUILD_IMAGE ?= vmlinux
1089
1090#
1091# INSTALL_PATH specifies where to place the updated kernel and system map
1092# images. Default is /boot, but you can set it to other values
1093export  INSTALL_PATH ?= /boot
1094
1095#
1096# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1097# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1098# an argument if needed. Otherwise it defaults to the kernel install path
1099#
1100export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1101
1102#
1103# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1104# relocations required by build roots.  This is not defined in the
1105# makefile but the argument can be passed to make if needed.
1106#
1107
1108MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1109export MODLIB
1110
1111PHONY += prepare0
1112
1113export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1114export MODORDER := $(extmod_prefix)modules.order
1115export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1116
1117ifeq ($(KBUILD_EXTMOD),)
1118core-y          += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1119
1120vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1121                     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1122                     $(libs-y) $(libs-m)))
1123
1124vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1125                     $(patsubst %/,%,$(filter %/, $(core-) \
1126                        $(drivers-) $(libs-))))
1127
1128subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1129                        $(core-y) $(core-m) $(libs-y) $(libs-m) \
1130                        $(drivers-y) $(drivers-m)))
1131
1132build-dirs      := $(vmlinux-dirs)
1133clean-dirs      := $(vmlinux-alldirs)
1134
1135# Externally visible symbols (used by link-vmlinux.sh)
1136KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1137KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1138ifdef CONFIG_MODULES
1139KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1140KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1141else
1142KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1143endif
1144KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1145
1146export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1147export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1148# used by scripts/Makefile.package
1149export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1150
1151vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1152
1153# Recurse until adjust_autoksyms.sh is satisfied
1154PHONY += autoksyms_recursive
1155ifdef CONFIG_TRIM_UNUSED_KSYMS
1156# For the kernel to actually contain only the needed exported symbols,
1157# we have to build modules as well to determine what those symbols are.
1158# (this can be evaluated only once include/config/auto.conf has been included)
1159KBUILD_MODULES := 1
1160
1161autoksyms_recursive: descend modules.order
1162        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1163          "$(MAKE) -f $(srctree)/Makefile vmlinux"
1164endif
1165
1166autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1167
1168quiet_cmd_autoksyms_h = GEN     $@
1169      cmd_autoksyms_h = mkdir -p $(dir $@); \
1170                        $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1171
1172$(autoksyms_h):
1173        $(call cmd,autoksyms_h)
1174
1175ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1176
1177# Final link of vmlinux with optional arch pass after final link
1178cmd_link-vmlinux =                                                 \
1179        $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1180        $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1181
1182vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1183        +$(call if_changed_dep,link-vmlinux)
1184
1185targets := vmlinux
1186
1187# The actual objects are generated when descending,
1188# make sure no implicit rule kicks in
1189$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1190
1191filechk_kernel.release = \
1192        echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1193
1194# Store (new) KERNELRELEASE string in include/config/kernel.release
1195include/config/kernel.release: FORCE
1196        $(call filechk,kernel.release)
1197
1198# Additional helpers built in scripts/
1199# Carefully list dependencies so we do not try to build scripts twice
1200# in parallel
1201PHONY += scripts
1202scripts: scripts_basic scripts_dtc
1203        $(Q)$(MAKE) $(build)=$(@)
1204
1205# Things we need to do before we recursively start building the kernel
1206# or the modules are listed in "prepare".
1207# A multi level approach is used. prepareN is processed before prepareN-1.
1208# archprepare is used in arch Makefiles and when processed asm symlink,
1209# version.h and scripts_basic is processed / created.
1210
1211PHONY += prepare archprepare
1212
1213archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1214        asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1215        include/generated/autoconf.h remove-stale-files
1216
1217prepare0: archprepare
1218        $(Q)$(MAKE) $(build)=scripts/mod
1219        $(Q)$(MAKE) $(build)=.
1220
1221# All the preparing..
1222prepare: prepare0
1223
1224PHONY += remove-stale-files
1225remove-stale-files:
1226        $(Q)$(srctree)/scripts/remove-stale-files
1227
1228# Support for using generic headers in asm-generic
1229asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1230
1231PHONY += asm-generic uapi-asm-generic
1232asm-generic: uapi-asm-generic
1233        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1234        generic=include/asm-generic
1235uapi-asm-generic:
1236        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1237        generic=include/uapi/asm-generic
1238
1239# Generate some files
1240# ---------------------------------------------------------------------------
1241
1242# KERNELRELEASE can change from a few different places, meaning version.h
1243# needs to be updated, so this check is forced on all builds
1244
1245uts_len := 64
1246define filechk_utsrelease.h
1247        if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1248          echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1249          exit 1;                                                         \
1250        fi;                                                               \
1251        echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1252endef
1253
1254define filechk_version.h
1255        if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1256                echo \#define LINUX_VERSION_CODE $(shell                 \
1257                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1258        else                                                             \
1259                echo \#define LINUX_VERSION_CODE $(shell                 \
1260                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1261        fi;                                                              \
1262        echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1263        ((c) > 255 ? 255 : (c)))';                                       \
1264        echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1265        echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1266        echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1267endef
1268
1269$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1270$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1271$(version_h): FORCE
1272        $(call filechk,version.h)
1273
1274include/generated/utsrelease.h: include/config/kernel.release FORCE
1275        $(call filechk,utsrelease.h)
1276
1277PHONY += headerdep
1278headerdep:
1279        $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1280        $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1281
1282# ---------------------------------------------------------------------------
1283# Kernel headers
1284
1285#Default location for installed headers
1286export INSTALL_HDR_PATH = $(objtree)/usr
1287
1288quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1289      cmd_headers_install = \
1290        mkdir -p $(INSTALL_HDR_PATH); \
1291        rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1292        usr/include $(INSTALL_HDR_PATH)
1293
1294PHONY += headers_install
1295headers_install: headers
1296        $(call cmd,headers_install)
1297
1298PHONY += archheaders archscripts
1299
1300hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1301
1302PHONY += headers
1303headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1304        $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1305          $(error Headers not exportable for the $(SRCARCH) architecture))
1306        $(Q)$(MAKE) $(hdr-inst)=include/uapi
1307        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1308
1309# Deprecated. It is no-op now.
1310PHONY += headers_check
1311headers_check:
1312        @echo >&2 "=================== WARNING ==================="
1313        @echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1314        @echo >&2 "and will be removed after Linux 5.15 release."
1315        @echo >&2 "Please remove headers_check from your scripts."
1316        @echo >&2 "==============================================="
1317
1318ifdef CONFIG_HEADERS_INSTALL
1319prepare: headers
1320endif
1321
1322PHONY += scripts_unifdef
1323scripts_unifdef: scripts_basic
1324        $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1325
1326# ---------------------------------------------------------------------------
1327# Install
1328
1329# Many distributions have the custom install script, /sbin/installkernel.
1330# If DKMS is installed, 'make install' will eventually recuses back
1331# to the this Makefile to build and install external modules.
1332# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1333
1334install: sub_make_done :=
1335
1336# ---------------------------------------------------------------------------
1337# Tools
1338
1339ifdef CONFIG_STACK_VALIDATION
1340prepare: tools/objtool
1341endif
1342
1343ifdef CONFIG_BPF
1344ifdef CONFIG_DEBUG_INFO_BTF
1345prepare: tools/bpf/resolve_btfids
1346endif
1347endif
1348
1349PHONY += resolve_btfids_clean
1350
1351resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1352
1353# tools/bpf/resolve_btfids directory might not exist
1354# in output directory, skip its clean in that case
1355resolve_btfids_clean:
1356ifneq ($(wildcard $(resolve_btfids_O)),)
1357        $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1358endif
1359
1360# Clear a bunch of variables before executing the submake
1361ifeq ($(quiet),silent_)
1362tools_silent=s
1363endif
1364
1365tools/: FORCE
1366        $(Q)mkdir -p $(objtree)/tools
1367        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1368
1369tools/%: FORCE
1370        $(Q)mkdir -p $(objtree)/tools
1371        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1372
1373# ---------------------------------------------------------------------------
1374# Kernel selftest
1375
1376PHONY += kselftest
1377kselftest:
1378        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1379
1380kselftest-%: FORCE
1381        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1382
1383PHONY += kselftest-merge
1384kselftest-merge:
1385        $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1386        $(Q)find $(srctree)/tools/testing/selftests -name config | \
1387                xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1388        $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1389
1390# ---------------------------------------------------------------------------
1391# Devicetree files
1392
1393ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1394dtstree := arch/$(SRCARCH)/boot/dts
1395endif
1396
1397ifneq ($(dtstree),)
1398
1399%.dtb: include/config/kernel.release scripts_dtc
1400        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1401
1402%.dtbo: include/config/kernel.release scripts_dtc
1403        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1404
1405PHONY += dtbs dtbs_install dtbs_check
1406dtbs: include/config/kernel.release scripts_dtc
1407        $(Q)$(MAKE) $(build)=$(dtstree)
1408
1409ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1410export CHECK_DTBS=y
1411dtbs: dt_binding_check
1412endif
1413
1414dtbs_check: dtbs
1415
1416dtbs_install:
1417        $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1418
1419ifdef CONFIG_OF_EARLY_FLATTREE
1420all: dtbs
1421endif
1422
1423endif
1424
1425PHONY += scripts_dtc
1426scripts_dtc: scripts_basic
1427        $(Q)$(MAKE) $(build)=scripts/dtc
1428
1429ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1430export CHECK_DT_BINDING=y
1431endif
1432
1433PHONY += dt_binding_check
1434dt_binding_check: scripts_dtc
1435        $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1436
1437# ---------------------------------------------------------------------------
1438# Modules
1439
1440ifdef CONFIG_MODULES
1441
1442# By default, build modules as well
1443
1444all: modules
1445
1446# When we're building modules with modversions, we need to consider
1447# the built-in objects during the descend as well, in order to
1448# make sure the checksums are up to date before we record them.
1449ifdef CONFIG_MODVERSIONS
1450  KBUILD_BUILTIN := 1
1451endif
1452
1453# Build modules
1454#
1455# A module can be listed more than once in obj-m resulting in
1456# duplicate lines in modules.order files.  Those are removed
1457# using awk while concatenating to the final file.
1458
1459PHONY += modules
1460modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1461
1462cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1463
1464modules.order: $(subdir-modorder) FORCE
1465        $(call if_changed,modules_order)
1466
1467targets += modules.order
1468
1469# Target to prepare building external modules
1470PHONY += modules_prepare
1471modules_prepare: prepare
1472        $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1473
1474export modules_sign_only :=
1475
1476ifeq ($(CONFIG_MODULE_SIG),y)
1477PHONY += modules_sign
1478modules_sign: modules_install
1479        @:
1480
1481# modules_sign is a subset of modules_install.
1482# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1483ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1484modules_sign_only := y
1485endif
1486endif
1487
1488modinst_pre :=
1489ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1490modinst_pre := __modinst_pre
1491endif
1492
1493modules_install: $(modinst_pre)
1494PHONY += __modinst_pre
1495__modinst_pre:
1496        @rm -rf $(MODLIB)/kernel
1497        @rm -f $(MODLIB)/source
1498        @mkdir -p $(MODLIB)/kernel
1499        @ln -s $(abspath $(srctree)) $(MODLIB)/source
1500        @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1501                rm -f $(MODLIB)/build ; \
1502                ln -s $(CURDIR) $(MODLIB)/build ; \
1503        fi
1504        @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1505        @cp -f modules.builtin $(MODLIB)/
1506        @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1507
1508endif # CONFIG_MODULES
1509
1510###
1511# Cleaning is done on three levels.
1512# make clean     Delete most generated files
1513#                Leave enough to build external modules
1514# make mrproper  Delete the current configuration, and all generated files
1515# make distclean Remove editor backup files, patch leftover files and the like
1516
1517# Directories & files removed with 'make clean'
1518CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1519               modules.builtin modules.builtin.modinfo modules.nsdeps \
1520               compile_commands.json .thinlto-cache
1521
1522# Directories & files removed with 'make mrproper'
1523MRPROPER_FILES += include/config include/generated          \
1524                  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1525                  debian snap tar-install \
1526                  .config .config.old .version \
1527                  Module.symvers \
1528                  certs/signing_key.pem certs/signing_key.x509 \
1529                  certs/x509.genkey \
1530                  vmlinux-gdb.py \
1531                  *.spec
1532
1533# clean - Delete most, but leave enough to build external modules
1534#
1535clean: rm-files := $(CLEAN_FILES)
1536
1537PHONY += archclean vmlinuxclean
1538
1539vmlinuxclean:
1540        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1541        $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1542
1543clean: archclean vmlinuxclean resolve_btfids_clean
1544
1545# mrproper - Delete all generated files, including .config
1546#
1547mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1548mrproper-dirs      := $(addprefix _mrproper_,scripts)
1549
1550PHONY += $(mrproper-dirs) mrproper
1551$(mrproper-dirs):
1552        $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1553
1554mrproper: clean $(mrproper-dirs)
1555        $(call cmd,rmfiles)
1556
1557# distclean
1558#
1559PHONY += distclean
1560
1561distclean: mrproper
1562        @find . $(RCS_FIND_IGNORE) \
1563                \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1564                -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1565                -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1566                -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1567                -type f -print | xargs rm -f
1568
1569
1570# Packaging of the kernel to various formats
1571# ---------------------------------------------------------------------------
1572
1573%src-pkg: FORCE
1574        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1575%pkg: include/config/kernel.release FORCE
1576        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1577
1578# Brief documentation of the typical targets used
1579# ---------------------------------------------------------------------------
1580
1581boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1582boards := $(sort $(notdir $(boards)))
1583board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1584board-dirs := $(sort $(notdir $(board-dirs:/=)))
1585
1586PHONY += help
1587help:
1588        @echo  'Cleaning targets:'
1589        @echo  '  clean           - Remove most generated files but keep the config and'
1590        @echo  '                    enough build support to build external modules'
1591        @echo  '  mrproper        - Remove all generated files + config + various backup files'
1592        @echo  '  distclean       - mrproper + remove editor backup and patch files'
1593        @echo  ''
1594        @echo  'Configuration targets:'
1595        @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1596        @echo  ''
1597        @echo  'Other generic targets:'
1598        @echo  '  all             - Build all targets marked with [*]'
1599        @echo  '* vmlinux         - Build the bare kernel'
1600        @echo  '* modules         - Build all modules'
1601        @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1602        @echo  '  dir/            - Build all files in dir and below'
1603        @echo  '  dir/file.[ois]  - Build specified target only'
1604        @echo  '  dir/file.ll     - Build the LLVM assembly file'
1605        @echo  '                    (requires compiler support for LLVM assembly generation)'
1606        @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1607        @echo  '                    (requires a recent binutils and recent build (System.map))'
1608        @echo  '  dir/file.ko     - Build module including final link'
1609        @echo  '  modules_prepare - Set up for building external modules'
1610        @echo  '  tags/TAGS       - Generate tags file for editors'
1611        @echo  '  cscope          - Generate cscope index'
1612        @echo  '  gtags           - Generate GNU GLOBAL index'
1613        @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1614        @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1615        @echo  '  image_name      - Output the image name (use with make -s)'
1616        @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1617         echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1618         echo  ''
1619        @echo  'Static analysers:'
1620        @echo  '  checkstack      - Generate a list of stack hogs'
1621        @echo  '  versioncheck    - Sanity check on version.h usage'
1622        @echo  '  includecheck    - Check for duplicate included header files'
1623        @echo  '  export_report   - List the usages of all exported symbols'
1624        @echo  '  headerdep       - Detect inclusion cycles in headers'
1625        @echo  '  coccicheck      - Check with Coccinelle'
1626        @echo  '  clang-analyzer  - Check with clang static analyzer'
1627        @echo  '  clang-tidy      - Check with clang-tidy'
1628        @echo  ''
1629        @echo  'Tools:'
1630        @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1631        @echo  ''
1632        @echo  'Kernel selftest:'
1633        @echo  '  kselftest         - Build and run kernel selftest'
1634        @echo  '                      Build, install, and boot kernel before'
1635        @echo  '                      running kselftest on it'
1636        @echo  '                      Run as root for full coverage'
1637        @echo  '  kselftest-all     - Build kernel selftest'
1638        @echo  '  kselftest-install - Build and install kernel selftest'
1639        @echo  '  kselftest-clean   - Remove all generated kselftest files'
1640        @echo  '  kselftest-merge   - Merge all the config dependencies of'
1641        @echo  '                      kselftest to existing .config.'
1642        @echo  ''
1643        @$(if $(dtstree), \
1644                echo 'Devicetree:'; \
1645                echo '* dtbs             - Build device tree blobs for enabled boards'; \
1646                echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1647                echo '  dt_binding_check - Validate device tree binding documents'; \
1648                echo '  dtbs_check       - Validate device tree source files';\
1649                echo '')
1650
1651        @echo 'Userspace tools targets:'
1652        @echo '  use "make tools/help"'
1653        @echo '  or  "cd tools; make help"'
1654        @echo  ''
1655        @echo  'Kernel packaging:'
1656        @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1657        @echo  ''
1658        @echo  'Documentation targets:'
1659        @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1660        @echo  ''
1661        @echo  'Architecture specific targets ($(SRCARCH)):'
1662        @$(if $(archhelp),$(archhelp),\
1663                echo '  No architecture specific help defined for $(SRCARCH)')
1664        @echo  ''
1665        @$(if $(boards), \
1666                $(foreach b, $(boards), \
1667                printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1668                echo '')
1669        @$(if $(board-dirs), \
1670                $(foreach b, $(board-dirs), \
1671                printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1672                printf "  %-16s - Show all of the above\\n" help-boards; \
1673                echo '')
1674
1675        @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1676        @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1677        @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1678        @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1679        @echo  '                       (sparse by default)'
1680        @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1681        @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1682        @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1683        @echo  '                1: warnings which may be relevant and do not occur too often'
1684        @echo  '                2: warnings which occur quite often but may still be relevant'
1685        @echo  '                3: more obscure warnings, can most likely be ignored'
1686        @echo  '                Multiple levels can be combined with W=12 or W=123'
1687        @echo  ''
1688        @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1689        @echo  'For further info see the ./README file'
1690
1691
1692help-board-dirs := $(addprefix help-,$(board-dirs))
1693
1694help-boards: $(help-board-dirs)
1695
1696boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1697
1698$(help-board-dirs): help-%:
1699        @echo  'Architecture specific targets ($(SRCARCH) $*):'
1700        @$(if $(boards-per-dir), \
1701                $(foreach b, $(boards-per-dir), \
1702                printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1703                echo '')
1704
1705
1706# Documentation targets
1707# ---------------------------------------------------------------------------
1708DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1709               linkcheckdocs dochelp refcheckdocs
1710PHONY += $(DOC_TARGETS)
1711$(DOC_TARGETS):
1712        $(Q)$(MAKE) $(build)=Documentation $@
1713
1714# Misc
1715# ---------------------------------------------------------------------------
1716
1717PHONY += scripts_gdb
1718scripts_gdb: prepare0
1719        $(Q)$(MAKE) $(build)=scripts/gdb
1720        $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1721
1722ifdef CONFIG_GDB_SCRIPTS
1723all: scripts_gdb
1724endif
1725
1726else # KBUILD_EXTMOD
1727
1728###
1729# External module support.
1730# When building external modules the kernel used as basis is considered
1731# read-only, and no consistency checks are made and the make
1732# system is not used on the basis kernel. If updates are required
1733# in the basis kernel ordinary make commands (without M=...) must be used.
1734
1735# We are always building only modules.
1736KBUILD_BUILTIN :=
1737KBUILD_MODULES := 1
1738
1739build-dirs := $(KBUILD_EXTMOD)
1740$(MODORDER): descend
1741        @:
1742
1743compile_commands.json: $(extmod_prefix)compile_commands.json
1744PHONY += compile_commands.json
1745
1746clean-dirs := $(KBUILD_EXTMOD)
1747clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1748        $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1749
1750PHONY += help
1751help:
1752        @echo  '  Building external modules.'
1753        @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1754        @echo  ''
1755        @echo  '  modules         - default target, build the module(s)'
1756        @echo  '  modules_install - install the module'
1757        @echo  '  clean           - remove generated files in module directory only'
1758        @echo  ''
1759
1760# no-op for external module builds
1761PHONY += prepare modules_prepare
1762
1763endif # KBUILD_EXTMOD
1764
1765# ---------------------------------------------------------------------------
1766# Modules
1767
1768PHONY += modules modules_install
1769
1770ifdef CONFIG_MODULES
1771
1772modules: modules_check
1773        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1774
1775PHONY += modules_check
1776modules_check: $(MODORDER)
1777        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1778
1779quiet_cmd_depmod = DEPMOD  $(MODLIB)
1780      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1781                   $(KERNELRELEASE)
1782
1783modules_install:
1784        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1785        $(call cmd,depmod)
1786
1787else # CONFIG_MODULES
1788
1789# Modules not configured
1790# ---------------------------------------------------------------------------
1791
1792modules modules_install:
1793        @echo >&2 '***'
1794        @echo >&2 '*** The present kernel configuration has modules disabled.'
1795        @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1796        @echo >&2 '*** to enable CONFIG_MODULES.'
1797        @echo >&2 '***'
1798        @exit 1
1799
1800endif # CONFIG_MODULES
1801
1802# Single targets
1803# ---------------------------------------------------------------------------
1804# To build individual files in subdirectories, you can do like this:
1805#
1806#   make foo/bar/baz.s
1807#
1808# The supported suffixes for single-target are listed in 'single-targets'
1809#
1810# To build only under specific subdirectories, you can do like this:
1811#
1812#   make foo/bar/baz/
1813
1814ifdef single-build
1815
1816# .ko is special because modpost is needed
1817single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1818single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1819
1820$(single-ko): single_modpost
1821        @:
1822$(single-no-ko): descend
1823        @:
1824
1825ifeq ($(KBUILD_EXTMOD),)
1826# For the single build of in-tree modules, use a temporary file to avoid
1827# the situation of modules_install installing an invalid modules.order.
1828MODORDER := .modules.tmp
1829endif
1830
1831PHONY += single_modpost
1832single_modpost: $(single-no-ko) modules_prepare
1833        $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1834        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1835
1836KBUILD_MODULES := 1
1837
1838export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1839
1840# trim unrelated directories
1841build-dirs := $(foreach d, $(build-dirs), \
1842                        $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1843
1844endif
1845
1846ifndef CONFIG_MODULES
1847KBUILD_MODULES :=
1848endif
1849
1850# Handle descending into subdirectories listed in $(build-dirs)
1851# Preset locale variables to speed up the build process. Limit locale
1852# tweaks to this spot to avoid wrong language settings when running
1853# make menuconfig etc.
1854# Error messages still appears in the original language
1855PHONY += descend $(build-dirs)
1856descend: $(build-dirs)
1857$(build-dirs): prepare
1858        $(Q)$(MAKE) $(build)=$@ \
1859        single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1860        need-builtin=1 need-modorder=1
1861
1862clean-dirs := $(addprefix _clean_, $(clean-dirs))
1863PHONY += $(clean-dirs) clean
1864$(clean-dirs):
1865        $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1866
1867clean: $(clean-dirs)
1868        $(call cmd,rmfiles)
1869        @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1870                \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1871                -o -name '*.ko.*' \
1872                -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1873                -o -name '*.dwo' -o -name '*.lst' \
1874                -o -name '*.su' -o -name '*.mod' \
1875                -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1876                -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1877                -o -name '*.asn1.[ch]' \
1878                -o -name '*.symtypes' -o -name 'modules.order' \
1879                -o -name '.tmp_*.o.*' \
1880                -o -name '*.c.[012]*.*' \
1881                -o -name '*.ll' \
1882                -o -name '*.gcno' \
1883                -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1884
1885# Generate tags for editors
1886# ---------------------------------------------------------------------------
1887quiet_cmd_tags = GEN     $@
1888      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1889
1890tags TAGS cscope gtags: FORCE
1891        $(call cmd,tags)
1892
1893# Script to generate missing namespace dependencies
1894# ---------------------------------------------------------------------------
1895
1896PHONY += nsdeps
1897nsdeps: export KBUILD_NSDEPS=1
1898nsdeps: modules
1899        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1900
1901# Clang Tooling
1902# ---------------------------------------------------------------------------
1903
1904quiet_cmd_gen_compile_commands = GEN     $@
1905      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1906
1907$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1908        $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1909        $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1910        $(call if_changed,gen_compile_commands)
1911
1912targets += $(extmod_prefix)compile_commands.json
1913
1914PHONY += clang-tidy clang-analyzer
1915
1916ifdef CONFIG_CC_IS_CLANG
1917quiet_cmd_clang_tools = CHECK   $<
1918      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1919
1920clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1921        $(call cmd,clang_tools)
1922else
1923clang-tidy clang-analyzer:
1924        @echo "$@ requires CC=clang" >&2
1925        @false
1926endif
1927
1928# Scripts to check various things for consistency
1929# ---------------------------------------------------------------------------
1930
1931PHONY += includecheck versioncheck coccicheck export_report
1932
1933includecheck:
1934        find $(srctree)/* $(RCS_FIND_IGNORE) \
1935                -name '*.[hcS]' -type f -print | sort \
1936                | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1937
1938versioncheck:
1939        find $(srctree)/* $(RCS_FIND_IGNORE) \
1940                -name '*.[hcS]' -type f -print | sort \
1941                | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1942
1943coccicheck:
1944        $(Q)$(BASH) $(srctree)/scripts/$@
1945
1946export_report:
1947        $(PERL) $(srctree)/scripts/export_report.pl
1948
1949PHONY += checkstack kernelrelease kernelversion image_name
1950
1951# UML needs a little special treatment here.  It wants to use the host
1952# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1953# else wants $(ARCH), including people doing cross-builds, which means
1954# that $(SUBARCH) doesn't work here.
1955ifeq ($(ARCH), um)
1956CHECKSTACK_ARCH := $(SUBARCH)
1957else
1958CHECKSTACK_ARCH := $(ARCH)
1959endif
1960checkstack:
1961        $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1962        $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1963
1964kernelrelease:
1965        @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1966
1967kernelversion:
1968        @echo $(KERNELVERSION)
1969
1970image_name:
1971        @echo $(KBUILD_IMAGE)
1972
1973quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1974      cmd_rmfiles = rm -rf $(rm-files)
1975
1976# read saved command lines for existing targets
1977existing-targets := $(wildcard $(sort $(targets)))
1978
1979-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1980
1981endif # config-build
1982endif # mixed-build
1983endif # need-sub-make
1984
1985PHONY += FORCE
1986FORCE:
1987
1988# Declare the contents of the PHONY variable as phony.  We keep that
1989# information in a variable so we can use it in if_changed and friends.
1990.PHONY: $(PHONY)
1991