linux/Makefile
<<
>>
Prefs
   1# SPDX-License-Identifier: GPL-2.0
   2VERSION = 5
   3PATCHLEVEL = 17
   4SUBLEVEL = 4
   5EXTRAVERSION =
   6NAME = Superb Owl
   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# --included-dir is added for backward compatibility, but you should not rely on
 195# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
 196MAKEFLAGS += --include-dir=$(abs_srctree)
 197endif
 198
 199ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 200# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
 201# We need to invoke sub-make to avoid implicit rules in the top Makefile.
 202need-sub-make := 1
 203# Cancel implicit rules for this Makefile.
 204$(this-makefile): ;
 205endif
 206
 207export abs_srctree abs_objtree
 208export sub_make_done := 1
 209
 210ifeq ($(need-sub-make),1)
 211
 212PHONY += $(MAKECMDGOALS) __sub-make
 213
 214$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 215        @:
 216
 217# Invoke a second make in the output directory, passing relevant variables
 218__sub-make:
 219        $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 220
 221endif # need-sub-make
 222endif # sub_make_done
 223
 224# We process the rest of the Makefile if this is the final invocation of make
 225ifeq ($(need-sub-make),)
 226
 227# Do not print "Entering directory ...",
 228# but we want to display it when entering to the output directory
 229# so that IDEs/editors are able to understand relative filenames.
 230MAKEFLAGS += --no-print-directory
 231
 232ifeq ($(abs_srctree),$(abs_objtree))
 233        # building in the source tree
 234        srctree := .
 235        building_out_of_srctree :=
 236else
 237        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
 238                # building in a subdirectory of the source tree
 239                srctree := ..
 240        else
 241                srctree := $(abs_srctree)
 242        endif
 243        building_out_of_srctree := 1
 244endif
 245
 246ifneq ($(KBUILD_ABS_SRCTREE),)
 247srctree := $(abs_srctree)
 248endif
 249
 250objtree         := .
 251VPATH           := $(srctree)
 252
 253export building_out_of_srctree srctree objtree VPATH
 254
 255# To make sure we do not include .config for any of the *config targets
 256# catch them early, and hand them over to scripts/kconfig/Makefile
 257# It is allowed to specify more targets when calling make, including
 258# mixing *config targets and build targets.
 259# For example 'make oldconfig all'.
 260# Detect when mixed targets is specified, and make a second invocation
 261# of make so .config is not included in this case either (for *config).
 262
 263version_h := include/generated/uapi/linux/version.h
 264
 265clean-targets := %clean mrproper cleandocs
 266no-dot-config-targets := $(clean-targets) \
 267                         cscope gtags TAGS tags help% %docs check% coccicheck \
 268                         $(version_h) headers headers_% archheaders archscripts \
 269                         %asm-generic kernelversion %src-pkg dt_binding_check \
 270                         outputmakefile
 271# Installation targets should not require compiler. Unfortunately, vdso_install
 272# is an exception where build artifacts may be updated. This must be fixed.
 273no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
 274                        headers_install modules_install kernelrelease image_name
 275no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
 276                          image_name
 277single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
 278
 279config-build    :=
 280mixed-build     :=
 281need-config     := 1
 282need-compiler   := 1
 283may-sync-config := 1
 284single-build    :=
 285
 286ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 287        ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 288                need-config :=
 289        endif
 290endif
 291
 292ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
 293        ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
 294                need-compiler :=
 295        endif
 296endif
 297
 298ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 299        ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 300                may-sync-config :=
 301        endif
 302endif
 303
 304ifneq ($(KBUILD_EXTMOD),)
 305        may-sync-config :=
 306endif
 307
 308ifeq ($(KBUILD_EXTMOD),)
 309        ifneq ($(filter %config,$(MAKECMDGOALS)),)
 310                config-build := 1
 311                ifneq ($(words $(MAKECMDGOALS)),1)
 312                        mixed-build := 1
 313                endif
 314        endif
 315endif
 316
 317# We cannot build single targets and the others at the same time
 318ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 319        single-build := 1
 320        ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 321                mixed-build := 1
 322        endif
 323endif
 324
 325# For "make -j clean all", "make -j mrproper defconfig all", etc.
 326ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 327        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 328                mixed-build := 1
 329        endif
 330endif
 331
 332# install and modules_install need also be processed one by one
 333ifneq ($(filter install,$(MAKECMDGOALS)),)
 334        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 335                mixed-build := 1
 336        endif
 337endif
 338
 339ifdef mixed-build
 340# ===========================================================================
 341# We're called with mixed targets (*config and build targets).
 342# Handle them one by one.
 343
 344PHONY += $(MAKECMDGOALS) __build_one_by_one
 345
 346$(MAKECMDGOALS): __build_one_by_one
 347        @:
 348
 349__build_one_by_one:
 350        $(Q)set -e; \
 351        for i in $(MAKECMDGOALS); do \
 352                $(MAKE) -f $(srctree)/Makefile $$i; \
 353        done
 354
 355else # !mixed-build
 356
 357include $(srctree)/scripts/Kbuild.include
 358
 359# Read KERNELRELEASE from include/config/kernel.release (if it exists)
 360KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 361KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 362export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 363
 364include $(srctree)/scripts/subarch.include
 365
 366# Cross compiling and selecting different set of gcc/bin-utils
 367# ---------------------------------------------------------------------------
 368#
 369# When performing cross compilation for other architectures ARCH shall be set
 370# to the target architecture. (See arch/* for the possibilities).
 371# ARCH can be set during invocation of make:
 372# make ARCH=ia64
 373# Another way is to have ARCH set in the environment.
 374# The default ARCH is the host where make is executed.
 375
 376# CROSS_COMPILE specify the prefix used for all executables used
 377# during compilation. Only gcc and related bin-utils executables
 378# are prefixed with $(CROSS_COMPILE).
 379# CROSS_COMPILE can be set on the command line
 380# make CROSS_COMPILE=ia64-linux-
 381# Alternatively CROSS_COMPILE can be set in the environment.
 382# Default value for CROSS_COMPILE is not to prefix executables
 383# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 384ARCH            ?= $(SUBARCH)
 385
 386# Architecture as present in compile.h
 387UTS_MACHINE     := $(ARCH)
 388SRCARCH         := $(ARCH)
 389
 390# Additional ARCH settings for x86
 391ifeq ($(ARCH),i386)
 392        SRCARCH := x86
 393endif
 394ifeq ($(ARCH),x86_64)
 395        SRCARCH := x86
 396endif
 397
 398# Additional ARCH settings for sparc
 399ifeq ($(ARCH),sparc32)
 400       SRCARCH := sparc
 401endif
 402ifeq ($(ARCH),sparc64)
 403       SRCARCH := sparc
 404endif
 405
 406# Additional ARCH settings for parisc
 407ifeq ($(ARCH),parisc64)
 408       SRCARCH := parisc
 409endif
 410
 411export cross_compiling :=
 412ifneq ($(SRCARCH),$(SUBARCH))
 413cross_compiling := 1
 414endif
 415
 416KCONFIG_CONFIG  ?= .config
 417export KCONFIG_CONFIG
 418
 419# SHELL used by kbuild
 420CONFIG_SHELL := sh
 421
 422HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 423HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 424HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 425
 426ifneq ($(LLVM),)
 427HOSTCC  = clang
 428HOSTCXX = clang++
 429else
 430HOSTCC  = gcc
 431HOSTCXX = g++
 432endif
 433
 434export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 435                              -O2 -fomit-frame-pointer -std=gnu89
 436export KBUILD_USERLDFLAGS :=
 437
 438KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 439KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 440KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 441KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 442
 443# Make variables (CC, etc...)
 444CPP             = $(CC) -E
 445ifneq ($(LLVM),)
 446CC              = clang
 447LD              = ld.lld
 448AR              = llvm-ar
 449NM              = llvm-nm
 450OBJCOPY         = llvm-objcopy
 451OBJDUMP         = llvm-objdump
 452READELF         = llvm-readelf
 453STRIP           = llvm-strip
 454else
 455CC              = $(CROSS_COMPILE)gcc
 456LD              = $(CROSS_COMPILE)ld
 457AR              = $(CROSS_COMPILE)ar
 458NM              = $(CROSS_COMPILE)nm
 459OBJCOPY         = $(CROSS_COMPILE)objcopy
 460OBJDUMP         = $(CROSS_COMPILE)objdump
 461READELF         = $(CROSS_COMPILE)readelf
 462STRIP           = $(CROSS_COMPILE)strip
 463endif
 464PAHOLE          = pahole
 465RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 466LEX             = flex
 467YACC            = bison
 468AWK             = awk
 469INSTALLKERNEL  := installkernel
 470DEPMOD          = depmod
 471PERL            = perl
 472PYTHON3         = python3
 473CHECK           = sparse
 474BASH            = bash
 475KGZIP           = gzip
 476KBZIP2          = bzip2
 477KLZOP           = lzop
 478LZMA            = lzma
 479LZ4             = lz4c
 480XZ              = xz
 481ZSTD            = zstd
 482
 483PAHOLE_FLAGS    = $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
 484
 485CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 486                  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 487NOSTDINC_FLAGS :=
 488CFLAGS_MODULE   =
 489AFLAGS_MODULE   =
 490LDFLAGS_MODULE  =
 491CFLAGS_KERNEL   =
 492AFLAGS_KERNEL   =
 493LDFLAGS_vmlinux =
 494
 495# Use USERINCLUDE when you must reference the UAPI directories only.
 496USERINCLUDE    := \
 497                -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 498                -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 499                -I$(srctree)/include/uapi \
 500                -I$(objtree)/include/generated/uapi \
 501                -include $(srctree)/include/linux/compiler-version.h \
 502                -include $(srctree)/include/linux/kconfig.h
 503
 504# Use LINUXINCLUDE when you must reference the include/ directory.
 505# Needed to be compatible with the O= option
 506LINUXINCLUDE    := \
 507                -I$(srctree)/arch/$(SRCARCH)/include \
 508                -I$(objtree)/arch/$(SRCARCH)/include/generated \
 509                $(if $(building_out_of_srctree),-I$(srctree)/include) \
 510                -I$(objtree)/include \
 511                $(USERINCLUDE)
 512
 513KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 514KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 515                   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 516                   -Werror=implicit-function-declaration -Werror=implicit-int \
 517                   -Werror=return-type -Wno-format-security \
 518                   -std=gnu89
 519KBUILD_CPPFLAGS := -D__KERNEL__
 520KBUILD_AFLAGS_KERNEL :=
 521KBUILD_CFLAGS_KERNEL :=
 522KBUILD_AFLAGS_MODULE  := -DMODULE
 523KBUILD_CFLAGS_MODULE  := -DMODULE
 524KBUILD_LDFLAGS_MODULE :=
 525KBUILD_LDFLAGS :=
 526CLANG_FLAGS :=
 527
 528export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
 529export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 530export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 531export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 532export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 533
 534export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 535export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 536export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 537export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 538export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 539export PAHOLE_FLAGS
 540
 541# Files to ignore in find ... statements
 542
 543export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 544                          -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 545                          -prune -o
 546export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 547                         --exclude CVS --exclude .pc --exclude .hg --exclude .git
 548
 549# ===========================================================================
 550# Rules shared between *config targets and build targets
 551
 552# Basic helpers built in scripts/basic/
 553PHONY += scripts_basic
 554scripts_basic:
 555        $(Q)$(MAKE) $(build)=scripts/basic
 556
 557PHONY += outputmakefile
 558ifdef building_out_of_srctree
 559# Before starting out-of-tree build, make sure the source tree is clean.
 560# outputmakefile generates a Makefile in the output directory, if using a
 561# separate output directory. This allows convenient use of make in the
 562# output directory.
 563# At the same time when output Makefile generated, generate .gitignore to
 564# ignore whole output directory
 565
 566quiet_cmd_makefile = GEN     Makefile
 567      cmd_makefile = { \
 568        echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
 569        echo "include $(srctree)/Makefile"; \
 570        } > Makefile
 571
 572outputmakefile:
 573        $(Q)if [ -f $(srctree)/.config -o \
 574                 -d $(srctree)/include/config -o \
 575                 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 576                echo >&2 "***"; \
 577                echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 578                echo >&2 "*** in $(abs_srctree)";\
 579                echo >&2 "***"; \
 580                false; \
 581        fi
 582        $(Q)ln -fsn $(srctree) source
 583        $(call cmd,makefile)
 584        $(Q)test -e .gitignore || \
 585        { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 586endif
 587
 588# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 589# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 590# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 591# and from include/config/auto.conf.cmd to detect the compiler upgrade.
 592CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
 593
 594ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 595include $(srctree)/scripts/Makefile.clang
 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 ($(KBUILD_EXTMOD),)
 665# Objects we will link into vmlinux / subdirs we need to visit
 666core-y          := init/ usr/ arch/$(SRCARCH)/
 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
 681ifdef CONFIG_CC_IS_GCC
 682CFLAGS_GCOV     += -fno-tree-loop-im
 683endif
 684export CFLAGS_GCOV
 685
 686# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 687ifdef CONFIG_FUNCTION_TRACER
 688  CC_FLAGS_FTRACE := -pg
 689endif
 690
 691include $(srctree)/arch/$(SRCARCH)/Makefile
 692
 693ifdef need-config
 694ifdef may-sync-config
 695# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 696# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 697# because some architectures define CROSS_COMPILE there.
 698include include/config/auto.conf.cmd
 699
 700$(KCONFIG_CONFIG):
 701        @echo >&2 '***'
 702        @echo >&2 '*** Configuration file "$@" not found!'
 703        @echo >&2 '***'
 704        @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 705        @echo >&2 '*** "make menuconfig" or "make xconfig").'
 706        @echo >&2 '***'
 707        @/bin/false
 708
 709# The actual configuration files used during the build are stored in
 710# include/generated/ and include/config/. Update them if .config is newer than
 711# include/config/auto.conf (which mirrors .config).
 712#
 713# This exploits the 'multi-target pattern rule' trick.
 714# The syncconfig should be executed only once to make all the targets.
 715# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 716#
 717# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
 718# so you cannot notice that Kconfig is waiting for the user input.
 719%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 720        $(Q)$(kecho) "  SYNC    $@"
 721        $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
 722else # !may-sync-config
 723# External modules and some install targets need include/generated/autoconf.h
 724# and include/config/auto.conf but do not care if they are up-to-date.
 725# Use auto.conf to trigger the test
 726PHONY += include/config/auto.conf
 727
 728include/config/auto.conf:
 729        $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 730        echo >&2;                                                       \
 731        echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 732        echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 733        echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 734        echo >&2 ;                                                      \
 735        /bin/false)
 736
 737endif # may-sync-config
 738endif # need-config
 739
 740KBUILD_CFLAGS   += -fno-delete-null-pointer-checks
 741KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 742KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 743KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 744KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 745
 746ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 747KBUILD_CFLAGS += -O2
 748else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
 749KBUILD_CFLAGS += -O3
 750else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 751KBUILD_CFLAGS += -Os
 752endif
 753
 754# Tell gcc to never replace conditional load with a non-conditional one
 755ifdef CONFIG_CC_IS_GCC
 756# gcc-10 renamed --param=allow-store-data-races=0 to
 757# -fno-allow-store-data-races.
 758KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 759KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 760endif
 761
 762ifdef CONFIG_READABLE_ASM
 763# Disable optimizations that make assembler listings hard to read.
 764# reorder blocks reorders the control in the function
 765# ipa clone creates specialized cloned functions
 766# partial inlining inlines only parts of functions
 767KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
 768endif
 769
 770ifneq ($(CONFIG_FRAME_WARN),0)
 771KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 772endif
 773
 774stackp-flags-y                                    := -fno-stack-protector
 775stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 776stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 777
 778KBUILD_CFLAGS += $(stackp-flags-y)
 779
 780KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
 781KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
 782
 783ifdef CONFIG_CC_IS_CLANG
 784KBUILD_CPPFLAGS += -Qunused-arguments
 785# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable.
 786KBUILD_CFLAGS += -Wno-gnu
 787# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
 788# source of a reference will be _MergedGlobals and not on of the whitelisted names.
 789# See modpost pattern 2
 790KBUILD_CFLAGS += -mno-global-merge
 791else
 792
 793# gcc inanely warns about local variables called 'main'
 794KBUILD_CFLAGS += -Wno-main
 795endif
 796
 797# These warnings generated too much noise in a regular build.
 798# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 799KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 800KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 801
 802ifdef CONFIG_FRAME_POINTER
 803KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 804else
 805# Some targets (ARM with Thumb2, for example), can't be built with frame
 806# pointers.  For those, we don't have FUNCTION_TRACER automatically
 807# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 808# incompatible with -fomit-frame-pointer with current GCC, so we don't use
 809# -fomit-frame-pointer with FUNCTION_TRACER.
 810ifndef CONFIG_FUNCTION_TRACER
 811KBUILD_CFLAGS   += -fomit-frame-pointer
 812endif
 813endif
 814
 815# Initialize all stack variables with a 0xAA pattern.
 816ifdef CONFIG_INIT_STACK_ALL_PATTERN
 817KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 818endif
 819
 820# Initialize all stack variables with a zero value.
 821ifdef CONFIG_INIT_STACK_ALL_ZERO
 822KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 823ifdef CONFIG_CC_IS_CLANG
 824# https://bugs.llvm.org/show_bug.cgi?id=45497
 825KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 826endif
 827endif
 828
 829# While VLAs have been removed, GCC produces unreachable stack probes
 830# for the randomize_kstack_offset feature. Disable it for all compilers.
 831KBUILD_CFLAGS   += $(call cc-option, -fno-stack-clash-protection)
 832
 833# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
 834ifdef CONFIG_ZERO_CALL_USED_REGS
 835KBUILD_CFLAGS   += -fzero-call-used-regs=used-gpr
 836endif
 837
 838ifdef CONFIG_FUNCTION_TRACER
 839ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 840  CC_FLAGS_FTRACE       += -mrecord-mcount
 841  ifdef CONFIG_HAVE_NOP_MCOUNT
 842    ifeq ($(call cc-option-yn, -mnop-mcount),y)
 843      CC_FLAGS_FTRACE   += -mnop-mcount
 844      CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 845    endif
 846  endif
 847endif
 848ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 849  CC_FLAGS_USING        += -DCC_USING_NOP_MCOUNT
 850endif
 851ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 852  ifdef CONFIG_HAVE_C_RECORDMCOUNT
 853    BUILD_C_RECORDMCOUNT := y
 854    export BUILD_C_RECORDMCOUNT
 855  endif
 856endif
 857ifdef CONFIG_HAVE_FENTRY
 858  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
 859  ifeq ($(call cc-option-yn, -mfentry),y)
 860    CC_FLAGS_FTRACE     += -mfentry
 861    CC_FLAGS_USING      += -DCC_USING_FENTRY
 862  endif
 863endif
 864export CC_FLAGS_FTRACE
 865KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 866KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 867endif
 868
 869# We trigger additional mismatches with less inlining
 870ifdef CONFIG_DEBUG_SECTION_MISMATCH
 871KBUILD_CFLAGS += -fno-inline-functions-called-once
 872endif
 873
 874ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 875KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 876LDFLAGS_vmlinux += --gc-sections
 877endif
 878
 879ifdef CONFIG_SHADOW_CALL_STACK
 880CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 881KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 882export CC_FLAGS_SCS
 883endif
 884
 885ifdef CONFIG_LTO_CLANG
 886ifdef CONFIG_LTO_CLANG_THIN
 887CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 888KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
 889else
 890CC_FLAGS_LTO    := -flto
 891endif
 892CC_FLAGS_LTO    += -fvisibility=hidden
 893
 894# Limit inlining across translation units to reduce binary size
 895KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 896
 897# Check for frame size exceeding threshold during prolog/epilog insertion
 898# when using lld < 13.0.0.
 899ifneq ($(CONFIG_FRAME_WARN),0)
 900ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
 901KBUILD_LDFLAGS  += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 902endif
 903endif
 904endif
 905
 906ifdef CONFIG_LTO
 907KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 908KBUILD_AFLAGS   += -fno-lto
 909export CC_FLAGS_LTO
 910endif
 911
 912ifdef CONFIG_CFI_CLANG
 913CC_FLAGS_CFI    := -fsanitize=cfi \
 914                   -fsanitize-cfi-cross-dso \
 915                   -fno-sanitize-cfi-canonical-jump-tables \
 916                   -fno-sanitize-trap=cfi \
 917                   -fno-sanitize-blacklist
 918
 919ifdef CONFIG_CFI_PERMISSIVE
 920CC_FLAGS_CFI    += -fsanitize-recover=cfi
 921endif
 922
 923# If LTO flags are filtered out, we must also filter out CFI.
 924CC_FLAGS_LTO    += $(CC_FLAGS_CFI)
 925KBUILD_CFLAGS   += $(CC_FLAGS_CFI)
 926export CC_FLAGS_CFI
 927endif
 928
 929ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
 930KBUILD_CFLAGS += -falign-functions=64
 931endif
 932
 933# arch Makefile may override CC so keep this after arch Makefile is included
 934NOSTDINC_FLAGS += -nostdinc
 935
 936# warn about C99 declaration after statement
 937KBUILD_CFLAGS += -Wdeclaration-after-statement
 938
 939# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 940KBUILD_CFLAGS += -Wvla
 941
 942# disable pointer signed / unsigned warnings in gcc 4.0
 943KBUILD_CFLAGS += -Wno-pointer-sign
 944
 945# In order to make sure new function cast mismatches are not introduced
 946# in the kernel (to avoid tripping CFI checking), the kernel should be
 947# globally built with -Wcast-function-type.
 948KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
 949
 950# disable stringop warnings in gcc 8+
 951KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 952
 953# We'll want to enable this eventually, but it's not going away for 5.7 at least
 954KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
 955KBUILD_CFLAGS += -Wno-array-bounds
 956KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
 957
 958# Another good warning that we'll want to enable eventually
 959KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 960
 961# Enabled with W=2, disabled by default as noisy
 962ifdef CONFIG_CC_IS_GCC
 963KBUILD_CFLAGS += -Wno-maybe-uninitialized
 964endif
 965
 966ifdef CONFIG_CC_IS_GCC
 967# The allocators already balk at large sizes, so silence the compiler
 968# warnings for bounds checks involving those possible values. While
 969# -Wno-alloc-size-larger-than would normally be used here, earlier versions
 970# of gcc (<9.1) weirdly don't handle the option correctly when _other_
 971# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
 972# doesn't work (as it is documented to), silently resolving to "0" prior to
 973# version 9.1 (and producing an error more recently). Numeric values larger
 974# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
 975# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
 976# choice, we must perform a versioned check to disable this warning.
 977# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
 978KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
 979endif
 980
 981# disable invalid "can't wrap" optimizations for signed / pointers
 982KBUILD_CFLAGS   += -fno-strict-overflow
 983
 984# Make sure -fstack-check isn't enabled (like gentoo apparently did)
 985KBUILD_CFLAGS  += -fno-stack-check
 986
 987# conserve stack if available
 988ifdef CONFIG_CC_IS_GCC
 989KBUILD_CFLAGS   += -fconserve-stack
 990endif
 991
 992# Prohibit date/time macros, which would make the build non-deterministic
 993KBUILD_CFLAGS   += -Werror=date-time
 994
 995# enforce correct pointer usage
 996KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
 997
 998# Require designated initializers for all marked structures
 999KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1000
1001# change __FILE__ to the relative path from the srctree
1002KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1003
1004# include additional Makefiles when needed
1005include-y                       := scripts/Makefile.extrawarn
1006include-$(CONFIG_DEBUG_INFO)    += scripts/Makefile.debug
1007include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
1008include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
1009include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
1010include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
1011include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
1012
1013include $(addprefix $(srctree)/, $(include-y))
1014
1015# scripts/Makefile.gcc-plugins is intentionally included last.
1016# Do not add $(call cc-option,...) below this line. When you build the kernel
1017# from the clean source tree, the GCC plugins do not exist at this point.
1018
1019# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1020KBUILD_CPPFLAGS += $(KCPPFLAGS)
1021KBUILD_AFLAGS   += $(KAFLAGS)
1022KBUILD_CFLAGS   += $(KCFLAGS)
1023
1024KBUILD_LDFLAGS_MODULE += --build-id=sha1
1025LDFLAGS_vmlinux += --build-id=sha1
1026
1027ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1028LDFLAGS_vmlinux += $(call ld-option, -X,)
1029endif
1030
1031ifeq ($(CONFIG_RELR),y)
1032LDFLAGS_vmlinux += --pack-dyn-relocs=relr --use-android-relr-tags
1033endif
1034
1035# We never want expected sections to be placed heuristically by the
1036# linker. All sections should be explicitly named in the linker script.
1037ifdef CONFIG_LD_ORPHAN_WARN
1038LDFLAGS_vmlinux += --orphan-handling=warn
1039endif
1040
1041# Align the bit size of userspace programs with the kernel
1042KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1043KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1044
1045# make the checker run with the right architecture
1046CHECKFLAGS += --arch=$(ARCH)
1047
1048# insure the checker run with the right endianness
1049CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1050
1051# the checker needs the correct machine size
1052CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1053
1054# Default kernel image to build when no specific target is given.
1055# KBUILD_IMAGE may be overruled on the command line or
1056# set in the environment
1057# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1058# this default value
1059export KBUILD_IMAGE ?= vmlinux
1060
1061#
1062# INSTALL_PATH specifies where to place the updated kernel and system map
1063# images. Default is /boot, but you can set it to other values
1064export  INSTALL_PATH ?= /boot
1065
1066#
1067# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1068# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1069# an argument if needed. Otherwise it defaults to the kernel install path
1070#
1071export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1072
1073#
1074# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1075# relocations required by build roots.  This is not defined in the
1076# makefile but the argument can be passed to make if needed.
1077#
1078
1079MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1080export MODLIB
1081
1082PHONY += prepare0
1083
1084export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1085export MODORDER := $(extmod_prefix)modules.order
1086export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1087
1088ifeq ($(KBUILD_EXTMOD),)
1089core-y                  += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
1090core-$(CONFIG_BLOCK)    += block/
1091
1092vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1093                     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1094                     $(libs-y) $(libs-m)))
1095
1096vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1097                     $(patsubst %/,%,$(filter %/, $(core-) \
1098                        $(drivers-) $(libs-))))
1099
1100subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1101                        $(core-y) $(core-m) $(libs-y) $(libs-m) \
1102                        $(drivers-y) $(drivers-m)))
1103
1104build-dirs      := $(vmlinux-dirs)
1105clean-dirs      := $(vmlinux-alldirs)
1106
1107# Externally visible symbols (used by link-vmlinux.sh)
1108KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1109KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1110ifdef CONFIG_MODULES
1111KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1112KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1113else
1114KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1115endif
1116KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1117
1118export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1119export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1120# used by scripts/Makefile.package
1121export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1122
1123vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1124
1125# Recurse until adjust_autoksyms.sh is satisfied
1126PHONY += autoksyms_recursive
1127ifdef CONFIG_TRIM_UNUSED_KSYMS
1128# For the kernel to actually contain only the needed exported symbols,
1129# we have to build modules as well to determine what those symbols are.
1130# (this can be evaluated only once include/config/auto.conf has been included)
1131KBUILD_MODULES := 1
1132
1133autoksyms_recursive: descend modules.order
1134        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1135          "$(MAKE) -f $(srctree)/Makefile vmlinux"
1136endif
1137
1138autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1139
1140quiet_cmd_autoksyms_h = GEN     $@
1141      cmd_autoksyms_h = mkdir -p $(dir $@); \
1142                        $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1143
1144$(autoksyms_h):
1145        $(call cmd,autoksyms_h)
1146
1147ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1148
1149# Final link of vmlinux with optional arch pass after final link
1150cmd_link-vmlinux =                                                 \
1151        $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1152        $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1153
1154vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1155        +$(call if_changed_dep,link-vmlinux)
1156
1157targets := vmlinux
1158
1159# The actual objects are generated when descending,
1160# make sure no implicit rule kicks in
1161$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1162
1163filechk_kernel.release = \
1164        echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1165
1166# Store (new) KERNELRELEASE string in include/config/kernel.release
1167include/config/kernel.release: FORCE
1168        $(call filechk,kernel.release)
1169
1170# Additional helpers built in scripts/
1171# Carefully list dependencies so we do not try to build scripts twice
1172# in parallel
1173PHONY += scripts
1174scripts: scripts_basic scripts_dtc
1175        $(Q)$(MAKE) $(build)=$(@)
1176
1177# Things we need to do before we recursively start building the kernel
1178# or the modules are listed in "prepare".
1179# A multi level approach is used. prepareN is processed before prepareN-1.
1180# archprepare is used in arch Makefiles and when processed asm symlink,
1181# version.h and scripts_basic is processed / created.
1182
1183PHONY += prepare archprepare
1184
1185archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1186        asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1187        include/generated/autoconf.h remove-stale-files
1188
1189prepare0: archprepare
1190        $(Q)$(MAKE) $(build)=scripts/mod
1191        $(Q)$(MAKE) $(build)=.
1192
1193# All the preparing..
1194prepare: prepare0
1195
1196PHONY += remove-stale-files
1197remove-stale-files:
1198        $(Q)$(srctree)/scripts/remove-stale-files
1199
1200# Support for using generic headers in asm-generic
1201asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1202
1203PHONY += asm-generic uapi-asm-generic
1204asm-generic: uapi-asm-generic
1205        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1206        generic=include/asm-generic
1207uapi-asm-generic:
1208        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1209        generic=include/uapi/asm-generic
1210
1211# Generate some files
1212# ---------------------------------------------------------------------------
1213
1214# KERNELRELEASE can change from a few different places, meaning version.h
1215# needs to be updated, so this check is forced on all builds
1216
1217uts_len := 64
1218define filechk_utsrelease.h
1219        if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1220          echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1221          exit 1;                                                         \
1222        fi;                                                               \
1223        echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1224endef
1225
1226define filechk_version.h
1227        if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1228                echo \#define LINUX_VERSION_CODE $(shell                 \
1229                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1230        else                                                             \
1231                echo \#define LINUX_VERSION_CODE $(shell                 \
1232                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1233        fi;                                                              \
1234        echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1235        ((c) > 255 ? 255 : (c)))';                                       \
1236        echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1237        echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1238        echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1239endef
1240
1241$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1242$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1243$(version_h): FORCE
1244        $(call filechk,version.h)
1245
1246include/generated/utsrelease.h: include/config/kernel.release FORCE
1247        $(call filechk,utsrelease.h)
1248
1249PHONY += headerdep
1250headerdep:
1251        $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1252        $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1253
1254# ---------------------------------------------------------------------------
1255# Kernel headers
1256
1257#Default location for installed headers
1258export INSTALL_HDR_PATH = $(objtree)/usr
1259
1260quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1261      cmd_headers_install = \
1262        mkdir -p $(INSTALL_HDR_PATH); \
1263        rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1264        usr/include $(INSTALL_HDR_PATH)
1265
1266PHONY += headers_install
1267headers_install: headers
1268        $(call cmd,headers_install)
1269
1270PHONY += archheaders archscripts
1271
1272hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1273
1274PHONY += headers
1275headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1276        $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1277          $(error Headers not exportable for the $(SRCARCH) architecture))
1278        $(Q)$(MAKE) $(hdr-inst)=include/uapi
1279        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1280
1281ifdef CONFIG_HEADERS_INSTALL
1282prepare: headers
1283endif
1284
1285PHONY += scripts_unifdef
1286scripts_unifdef: scripts_basic
1287        $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1288
1289# ---------------------------------------------------------------------------
1290# Install
1291
1292# Many distributions have the custom install script, /sbin/installkernel.
1293# If DKMS is installed, 'make install' will eventually recuses back
1294# to the this Makefile to build and install external modules.
1295# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1296
1297install: sub_make_done :=
1298
1299# ---------------------------------------------------------------------------
1300# Tools
1301
1302ifdef CONFIG_STACK_VALIDATION
1303prepare: tools/objtool
1304endif
1305
1306ifdef CONFIG_BPF
1307ifdef CONFIG_DEBUG_INFO_BTF
1308prepare: tools/bpf/resolve_btfids
1309endif
1310endif
1311
1312PHONY += resolve_btfids_clean
1313
1314resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1315
1316# tools/bpf/resolve_btfids directory might not exist
1317# in output directory, skip its clean in that case
1318resolve_btfids_clean:
1319ifneq ($(wildcard $(resolve_btfids_O)),)
1320        $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1321endif
1322
1323# Clear a bunch of variables before executing the submake
1324ifeq ($(quiet),silent_)
1325tools_silent=s
1326endif
1327
1328tools/: FORCE
1329        $(Q)mkdir -p $(objtree)/tools
1330        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1331
1332tools/%: FORCE
1333        $(Q)mkdir -p $(objtree)/tools
1334        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1335
1336# ---------------------------------------------------------------------------
1337# Kernel selftest
1338
1339PHONY += kselftest
1340kselftest:
1341        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1342
1343kselftest-%: FORCE
1344        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1345
1346PHONY += kselftest-merge
1347kselftest-merge:
1348        $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1349        $(Q)find $(srctree)/tools/testing/selftests -name config | \
1350                xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1351        $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1352
1353# ---------------------------------------------------------------------------
1354# Devicetree files
1355
1356ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1357dtstree := arch/$(SRCARCH)/boot/dts
1358endif
1359
1360ifneq ($(dtstree),)
1361
1362%.dtb: include/config/kernel.release scripts_dtc
1363        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1364
1365%.dtbo: include/config/kernel.release scripts_dtc
1366        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1367
1368PHONY += dtbs dtbs_install dtbs_check
1369dtbs: include/config/kernel.release scripts_dtc
1370        $(Q)$(MAKE) $(build)=$(dtstree)
1371
1372ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1373export CHECK_DTBS=y
1374dtbs: dt_binding_check
1375endif
1376
1377dtbs_check: dtbs
1378
1379dtbs_install:
1380        $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1381
1382ifdef CONFIG_OF_EARLY_FLATTREE
1383all: dtbs
1384endif
1385
1386endif
1387
1388PHONY += scripts_dtc
1389scripts_dtc: scripts_basic
1390        $(Q)$(MAKE) $(build)=scripts/dtc
1391
1392ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1393export CHECK_DT_BINDING=y
1394endif
1395
1396PHONY += dt_binding_check
1397dt_binding_check: scripts_dtc
1398        $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1399
1400# ---------------------------------------------------------------------------
1401# Modules
1402
1403ifdef CONFIG_MODULES
1404
1405# By default, build modules as well
1406
1407all: modules
1408
1409# When we're building modules with modversions, we need to consider
1410# the built-in objects during the descend as well, in order to
1411# make sure the checksums are up to date before we record them.
1412ifdef CONFIG_MODVERSIONS
1413  KBUILD_BUILTIN := 1
1414endif
1415
1416# Build modules
1417#
1418# A module can be listed more than once in obj-m resulting in
1419# duplicate lines in modules.order files.  Those are removed
1420# using awk while concatenating to the final file.
1421
1422PHONY += modules
1423modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1424
1425cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1426
1427modules.order: $(subdir-modorder) FORCE
1428        $(call if_changed,modules_order)
1429
1430targets += modules.order
1431
1432# Target to prepare building external modules
1433PHONY += modules_prepare
1434modules_prepare: prepare
1435        $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1436
1437export modules_sign_only :=
1438
1439ifeq ($(CONFIG_MODULE_SIG),y)
1440PHONY += modules_sign
1441modules_sign: modules_install
1442        @:
1443
1444# modules_sign is a subset of modules_install.
1445# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1446ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1447modules_sign_only := y
1448endif
1449endif
1450
1451modinst_pre :=
1452ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1453modinst_pre := __modinst_pre
1454endif
1455
1456modules_install: $(modinst_pre)
1457PHONY += __modinst_pre
1458__modinst_pre:
1459        @rm -rf $(MODLIB)/kernel
1460        @rm -f $(MODLIB)/source
1461        @mkdir -p $(MODLIB)/kernel
1462        @ln -s $(abspath $(srctree)) $(MODLIB)/source
1463        @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1464                rm -f $(MODLIB)/build ; \
1465                ln -s $(CURDIR) $(MODLIB)/build ; \
1466        fi
1467        @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1468        @cp -f modules.builtin $(MODLIB)/
1469        @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1470
1471endif # CONFIG_MODULES
1472
1473###
1474# Cleaning is done on three levels.
1475# make clean     Delete most generated files
1476#                Leave enough to build external modules
1477# make mrproper  Delete the current configuration, and all generated files
1478# make distclean Remove editor backup files, patch leftover files and the like
1479
1480# Directories & files removed with 'make clean'
1481CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1482               modules.builtin modules.builtin.modinfo modules.nsdeps \
1483               compile_commands.json .thinlto-cache
1484
1485# Directories & files removed with 'make mrproper'
1486MRPROPER_FILES += include/config include/generated          \
1487                  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1488                  debian snap tar-install \
1489                  .config .config.old .version \
1490                  Module.symvers \
1491                  certs/signing_key.pem \
1492                  certs/x509.genkey \
1493                  vmlinux-gdb.py \
1494                  *.spec
1495
1496# clean - Delete most, but leave enough to build external modules
1497#
1498clean: rm-files := $(CLEAN_FILES)
1499
1500PHONY += archclean vmlinuxclean
1501
1502vmlinuxclean:
1503        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1504        $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1505
1506clean: archclean vmlinuxclean resolve_btfids_clean
1507
1508# mrproper - Delete all generated files, including .config
1509#
1510mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1511mrproper-dirs      := $(addprefix _mrproper_,scripts)
1512
1513PHONY += $(mrproper-dirs) mrproper
1514$(mrproper-dirs):
1515        $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1516
1517mrproper: clean $(mrproper-dirs)
1518        $(call cmd,rmfiles)
1519
1520# distclean
1521#
1522PHONY += distclean
1523
1524distclean: mrproper
1525        @find . $(RCS_FIND_IGNORE) \
1526                \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1527                -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1528                -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1529                -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1530                -type f -print | xargs rm -f
1531
1532
1533# Packaging of the kernel to various formats
1534# ---------------------------------------------------------------------------
1535
1536%src-pkg: FORCE
1537        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1538%pkg: include/config/kernel.release FORCE
1539        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1540
1541# Brief documentation of the typical targets used
1542# ---------------------------------------------------------------------------
1543
1544boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1545boards := $(sort $(notdir $(boards)))
1546board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1547board-dirs := $(sort $(notdir $(board-dirs:/=)))
1548
1549PHONY += help
1550help:
1551        @echo  'Cleaning targets:'
1552        @echo  '  clean           - Remove most generated files but keep the config and'
1553        @echo  '                    enough build support to build external modules'
1554        @echo  '  mrproper        - Remove all generated files + config + various backup files'
1555        @echo  '  distclean       - mrproper + remove editor backup and patch files'
1556        @echo  ''
1557        @echo  'Configuration targets:'
1558        @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1559        @echo  ''
1560        @echo  'Other generic targets:'
1561        @echo  '  all             - Build all targets marked with [*]'
1562        @echo  '* vmlinux         - Build the bare kernel'
1563        @echo  '* modules         - Build all modules'
1564        @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1565        @echo  '  dir/            - Build all files in dir and below'
1566        @echo  '  dir/file.[ois]  - Build specified target only'
1567        @echo  '  dir/file.ll     - Build the LLVM assembly file'
1568        @echo  '                    (requires compiler support for LLVM assembly generation)'
1569        @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1570        @echo  '                    (requires a recent binutils and recent build (System.map))'
1571        @echo  '  dir/file.ko     - Build module including final link'
1572        @echo  '  modules_prepare - Set up for building external modules'
1573        @echo  '  tags/TAGS       - Generate tags file for editors'
1574        @echo  '  cscope          - Generate cscope index'
1575        @echo  '  gtags           - Generate GNU GLOBAL index'
1576        @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1577        @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1578        @echo  '  image_name      - Output the image name (use with make -s)'
1579        @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1580         echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1581         echo  ''
1582        @echo  'Static analysers:'
1583        @echo  '  checkstack      - Generate a list of stack hogs'
1584        @echo  '  versioncheck    - Sanity check on version.h usage'
1585        @echo  '  includecheck    - Check for duplicate included header files'
1586        @echo  '  export_report   - List the usages of all exported symbols'
1587        @echo  '  headerdep       - Detect inclusion cycles in headers'
1588        @echo  '  coccicheck      - Check with Coccinelle'
1589        @echo  '  clang-analyzer  - Check with clang static analyzer'
1590        @echo  '  clang-tidy      - Check with clang-tidy'
1591        @echo  ''
1592        @echo  'Tools:'
1593        @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1594        @echo  ''
1595        @echo  'Kernel selftest:'
1596        @echo  '  kselftest         - Build and run kernel selftest'
1597        @echo  '                      Build, install, and boot kernel before'
1598        @echo  '                      running kselftest on it'
1599        @echo  '                      Run as root for full coverage'
1600        @echo  '  kselftest-all     - Build kernel selftest'
1601        @echo  '  kselftest-install - Build and install kernel selftest'
1602        @echo  '  kselftest-clean   - Remove all generated kselftest files'
1603        @echo  '  kselftest-merge   - Merge all the config dependencies of'
1604        @echo  '                      kselftest to existing .config.'
1605        @echo  ''
1606        @$(if $(dtstree), \
1607                echo 'Devicetree:'; \
1608                echo '* dtbs             - Build device tree blobs for enabled boards'; \
1609                echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1610                echo '  dt_binding_check - Validate device tree binding documents'; \
1611                echo '  dtbs_check       - Validate device tree source files';\
1612                echo '')
1613
1614        @echo 'Userspace tools targets:'
1615        @echo '  use "make tools/help"'
1616        @echo '  or  "cd tools; make help"'
1617        @echo  ''
1618        @echo  'Kernel packaging:'
1619        @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1620        @echo  ''
1621        @echo  'Documentation targets:'
1622        @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1623        @echo  ''
1624        @echo  'Architecture specific targets ($(SRCARCH)):'
1625        @$(if $(archhelp),$(archhelp),\
1626                echo '  No architecture specific help defined for $(SRCARCH)')
1627        @echo  ''
1628        @$(if $(boards), \
1629                $(foreach b, $(boards), \
1630                printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1631                echo '')
1632        @$(if $(board-dirs), \
1633                $(foreach b, $(board-dirs), \
1634                printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1635                printf "  %-16s - Show all of the above\\n" help-boards; \
1636                echo '')
1637
1638        @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1639        @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1640        @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1641        @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1642        @echo  '                       (sparse by default)'
1643        @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1644        @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1645        @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1646        @echo  '                1: warnings which may be relevant and do not occur too often'
1647        @echo  '                2: warnings which occur quite often but may still be relevant'
1648        @echo  '                3: more obscure warnings, can most likely be ignored'
1649        @echo  '                Multiple levels can be combined with W=12 or W=123'
1650        @echo  ''
1651        @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1652        @echo  'For further info see the ./README file'
1653
1654
1655help-board-dirs := $(addprefix help-,$(board-dirs))
1656
1657help-boards: $(help-board-dirs)
1658
1659boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1660
1661$(help-board-dirs): help-%:
1662        @echo  'Architecture specific targets ($(SRCARCH) $*):'
1663        @$(if $(boards-per-dir), \
1664                $(foreach b, $(boards-per-dir), \
1665                printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1666                echo '')
1667
1668
1669# Documentation targets
1670# ---------------------------------------------------------------------------
1671DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1672               linkcheckdocs dochelp refcheckdocs
1673PHONY += $(DOC_TARGETS)
1674$(DOC_TARGETS):
1675        $(Q)$(MAKE) $(build)=Documentation $@
1676
1677# Misc
1678# ---------------------------------------------------------------------------
1679
1680PHONY += scripts_gdb
1681scripts_gdb: prepare0
1682        $(Q)$(MAKE) $(build)=scripts/gdb
1683        $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1684
1685ifdef CONFIG_GDB_SCRIPTS
1686all: scripts_gdb
1687endif
1688
1689else # KBUILD_EXTMOD
1690
1691###
1692# External module support.
1693# When building external modules the kernel used as basis is considered
1694# read-only, and no consistency checks are made and the make
1695# system is not used on the basis kernel. If updates are required
1696# in the basis kernel ordinary make commands (without M=...) must be used.
1697
1698# We are always building only modules.
1699KBUILD_BUILTIN :=
1700KBUILD_MODULES := 1
1701
1702build-dirs := $(KBUILD_EXTMOD)
1703$(MODORDER): descend
1704        @:
1705
1706compile_commands.json: $(extmod_prefix)compile_commands.json
1707PHONY += compile_commands.json
1708
1709clean-dirs := $(KBUILD_EXTMOD)
1710clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1711        $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1712
1713PHONY += prepare
1714# now expand this into a simple variable to reduce the cost of shell evaluations
1715prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1716prepare:
1717        @if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1718                echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1719                echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1720                echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1721        fi
1722
1723PHONY += help
1724help:
1725        @echo  '  Building external modules.'
1726        @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1727        @echo  ''
1728        @echo  '  modules         - default target, build the module(s)'
1729        @echo  '  modules_install - install the module'
1730        @echo  '  clean           - remove generated files in module directory only'
1731        @echo  ''
1732
1733# no-op for external module builds
1734PHONY += modules_prepare
1735
1736endif # KBUILD_EXTMOD
1737
1738# ---------------------------------------------------------------------------
1739# Modules
1740
1741PHONY += modules modules_install
1742
1743ifdef CONFIG_MODULES
1744
1745modules: modules_check
1746        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1747
1748PHONY += modules_check
1749modules_check: $(MODORDER)
1750        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1751
1752quiet_cmd_depmod = DEPMOD  $(MODLIB)
1753      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1754                   $(KERNELRELEASE)
1755
1756modules_install:
1757        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1758        $(call cmd,depmod)
1759
1760else # CONFIG_MODULES
1761
1762# Modules not configured
1763# ---------------------------------------------------------------------------
1764
1765modules modules_install:
1766        @echo >&2 '***'
1767        @echo >&2 '*** The present kernel configuration has modules disabled.'
1768        @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1769        @echo >&2 '*** to enable CONFIG_MODULES.'
1770        @echo >&2 '***'
1771        @exit 1
1772
1773endif # CONFIG_MODULES
1774
1775# Single targets
1776# ---------------------------------------------------------------------------
1777# To build individual files in subdirectories, you can do like this:
1778#
1779#   make foo/bar/baz.s
1780#
1781# The supported suffixes for single-target are listed in 'single-targets'
1782#
1783# To build only under specific subdirectories, you can do like this:
1784#
1785#   make foo/bar/baz/
1786
1787ifdef single-build
1788
1789# .ko is special because modpost is needed
1790single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1791single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1792
1793$(single-ko): single_modpost
1794        @:
1795$(single-no-ko): descend
1796        @:
1797
1798ifeq ($(KBUILD_EXTMOD),)
1799# For the single build of in-tree modules, use a temporary file to avoid
1800# the situation of modules_install installing an invalid modules.order.
1801MODORDER := .modules.tmp
1802endif
1803
1804PHONY += single_modpost
1805single_modpost: $(single-no-ko) modules_prepare
1806        $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1807        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1808
1809KBUILD_MODULES := 1
1810
1811export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1812
1813# trim unrelated directories
1814build-dirs := $(foreach d, $(build-dirs), \
1815                        $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1816
1817endif
1818
1819ifndef CONFIG_MODULES
1820KBUILD_MODULES :=
1821endif
1822
1823# Handle descending into subdirectories listed in $(build-dirs)
1824# Preset locale variables to speed up the build process. Limit locale
1825# tweaks to this spot to avoid wrong language settings when running
1826# make menuconfig etc.
1827# Error messages still appears in the original language
1828PHONY += descend $(build-dirs)
1829descend: $(build-dirs)
1830$(build-dirs): prepare
1831        $(Q)$(MAKE) $(build)=$@ \
1832        single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1833        need-builtin=1 need-modorder=1
1834
1835clean-dirs := $(addprefix _clean_, $(clean-dirs))
1836PHONY += $(clean-dirs) clean
1837$(clean-dirs):
1838        $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1839
1840clean: $(clean-dirs)
1841        $(call cmd,rmfiles)
1842        @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1843                \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1844                -o -name '*.ko.*' \
1845                -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1846                -o -name '*.dwo' -o -name '*.lst' \
1847                -o -name '*.su' -o -name '*.mod' \
1848                -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1849                -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1850                -o -name '*.asn1.[ch]' \
1851                -o -name '*.symtypes' -o -name 'modules.order' \
1852                -o -name '.tmp_*.o.*' \
1853                -o -name '*.c.[012]*.*' \
1854                -o -name '*.ll' \
1855                -o -name '*.gcno' \
1856                -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1857
1858# Generate tags for editors
1859# ---------------------------------------------------------------------------
1860quiet_cmd_tags = GEN     $@
1861      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1862
1863tags TAGS cscope gtags: FORCE
1864        $(call cmd,tags)
1865
1866# Script to generate missing namespace dependencies
1867# ---------------------------------------------------------------------------
1868
1869PHONY += nsdeps
1870nsdeps: export KBUILD_NSDEPS=1
1871nsdeps: modules
1872        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1873
1874# Clang Tooling
1875# ---------------------------------------------------------------------------
1876
1877quiet_cmd_gen_compile_commands = GEN     $@
1878      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1879
1880$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1881        $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1882        $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1883        $(call if_changed,gen_compile_commands)
1884
1885targets += $(extmod_prefix)compile_commands.json
1886
1887PHONY += clang-tidy clang-analyzer
1888
1889ifdef CONFIG_CC_IS_CLANG
1890quiet_cmd_clang_tools = CHECK   $<
1891      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1892
1893clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1894        $(call cmd,clang_tools)
1895else
1896clang-tidy clang-analyzer:
1897        @echo "$@ requires CC=clang" >&2
1898        @false
1899endif
1900
1901# Scripts to check various things for consistency
1902# ---------------------------------------------------------------------------
1903
1904PHONY += includecheck versioncheck coccicheck export_report
1905
1906includecheck:
1907        find $(srctree)/* $(RCS_FIND_IGNORE) \
1908                -name '*.[hcS]' -type f -print | sort \
1909                | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1910
1911versioncheck:
1912        find $(srctree)/* $(RCS_FIND_IGNORE) \
1913                -name '*.[hcS]' -type f -print | sort \
1914                | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1915
1916coccicheck:
1917        $(Q)$(BASH) $(srctree)/scripts/$@
1918
1919export_report:
1920        $(PERL) $(srctree)/scripts/export_report.pl
1921
1922PHONY += checkstack kernelrelease kernelversion image_name
1923
1924# UML needs a little special treatment here.  It wants to use the host
1925# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1926# else wants $(ARCH), including people doing cross-builds, which means
1927# that $(SUBARCH) doesn't work here.
1928ifeq ($(ARCH), um)
1929CHECKSTACK_ARCH := $(SUBARCH)
1930else
1931CHECKSTACK_ARCH := $(ARCH)
1932endif
1933checkstack:
1934        $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1935        $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1936
1937kernelrelease:
1938        @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1939
1940kernelversion:
1941        @echo $(KERNELVERSION)
1942
1943image_name:
1944        @echo $(KBUILD_IMAGE)
1945
1946quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1947      cmd_rmfiles = rm -rf $(rm-files)
1948
1949# read saved command lines for existing targets
1950existing-targets := $(wildcard $(sort $(targets)))
1951
1952-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1953
1954endif # config-build
1955endif # mixed-build
1956endif # need-sub-make
1957
1958PHONY += FORCE
1959FORCE:
1960
1961# Declare the contents of the PHONY variable as phony.  We keep that
1962# information in a variable so we can use it in if_changed and friends.
1963.PHONY: $(PHONY)
1964