LXR linux/Makefile

   1# SPDX-License-Identifier: GPL-2.0
   2VERSION = 6
   3PATCHLEVEL = 0
   4SUBLEVEL = 9
   5EXTRAVERSION =
   6NAME = Hurr durr I'ma ninja sloth
   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        $(error building multiple external modules is not supported))
 131
 132$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
 133        $(error module directory path cannot contain '$x')))
 134
 135# Remove trailing slashes
 136ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
 137KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
 138endif
 139
 140export KBUILD_EXTMOD
 141
 142# Kbuild will save output files in the current working directory.
 143# This does not need to match to the root of the kernel source tree.
 144#
 145# For example, you can do this:
 146#
 147#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
 148#
 149# If you want to save output files in a different location, there are
 150# two syntaxes to specify it.
 151#
 152# 1) O=
 153# Use "make O=dir/to/store/output/files/"
 154#
 155# 2) Set KBUILD_OUTPUT
 156# Set the environment variable KBUILD_OUTPUT to point to the output directory.
 157# export KBUILD_OUTPUT=dir/to/store/output/files/; make
 158#
 159# The O= assignment takes precedence over the KBUILD_OUTPUT environment
 160# variable.
 161
 162# Do we want to change the working directory?
 163ifeq ("$(origin O)", "command line")
 164  KBUILD_OUTPUT := $(O)
 165endif
 166
 167ifneq ($(KBUILD_OUTPUT),)
 168# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
 169# expand a shell special character '~'. We use a somewhat tedious way here.
 170abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
 171$(if $(abs_objtree),, \
 172     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
 173
 174# $(realpath ...) resolves symlinks
 175abs_objtree := $(realpath $(abs_objtree))
 176else
 177abs_objtree := $(CURDIR)
 178endif # ifneq ($(KBUILD_OUTPUT),)
 179
 180ifeq ($(abs_objtree),$(CURDIR))
 181# Suppress "Entering directory ..." unless we are changing the work directory.
 182MAKEFLAGS += --no-print-directory
 183else
 184need-sub-make := 1
 185endif
 186
 187this-makefile := $(lastword $(MAKEFILE_LIST))
 188abs_srctree := $(realpath $(dir $(this-makefile)))
 189
 190ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
 191$(error source directory cannot contain spaces or colons)
 192endif
 193
 194ifneq ($(abs_srctree),$(abs_objtree))
 195# Look for make include files relative to root of kernel src
 196#
 197# --included-dir is added for backward compatibility, but you should not rely on
 198# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
 199MAKEFLAGS += --include-dir=$(abs_srctree)
 200endif
 201
 202ifneq ($(filter 3.%,$(MAKE_VERSION)),)
 203# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
 204# We need to invoke sub-make to avoid implicit rules in the top Makefile.
 205need-sub-make := 1
 206# Cancel implicit rules for this Makefile.
 207$(this-makefile): ;
 208endif
 209
 210export abs_srctree abs_objtree
 211export sub_make_done := 1
 212
 213ifeq ($(need-sub-make),1)
 214
 215PHONY += $(MAKECMDGOALS) __sub-make
 216
 217$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
 218        @:
 219
 220# Invoke a second make in the output directory, passing relevant variables
 221__sub-make:
 222        $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
 223
 224endif # need-sub-make
 225endif # sub_make_done
 226
 227# We process the rest of the Makefile if this is the final invocation of make
 228ifeq ($(need-sub-make),)
 229
 230# Do not print "Entering directory ...",
 231# but we want to display it when entering to the output directory
 232# so that IDEs/editors are able to understand relative filenames.
 233MAKEFLAGS += --no-print-directory
 234
 235ifeq ($(abs_srctree),$(abs_objtree))
 236        # building in the source tree
 237        srctree := .
 238        building_out_of_srctree :=
 239else
 240        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
 241                # building in a subdirectory of the source tree
 242                srctree := ..
 243        else
 244                srctree := $(abs_srctree)
 245        endif
 246        building_out_of_srctree := 1
 247endif
 248
 249ifneq ($(KBUILD_ABS_SRCTREE),)
 250srctree := $(abs_srctree)
 251endif
 252
 253objtree         := .
 254VPATH           := $(srctree)
 255
 256export building_out_of_srctree srctree objtree VPATH
 257
 258# To make sure we do not include .config for any of the *config targets
 259# catch them early, and hand them over to scripts/kconfig/Makefile
 260# It is allowed to specify more targets when calling make, including
 261# mixing *config targets and build targets.
 262# For example 'make oldconfig all'.
 263# Detect when mixed targets is specified, and make a second invocation
 264# of make so .config is not included in this case either (for *config).
 265
 266version_h := include/generated/uapi/linux/version.h
 267
 268clean-targets := %clean mrproper cleandocs
 269no-dot-config-targets := $(clean-targets) \
 270                         cscope gtags TAGS tags help% %docs check% coccicheck \
 271                         $(version_h) headers headers_% archheaders archscripts \
 272                         %asm-generic kernelversion %src-pkg dt_binding_check \
 273                         outputmakefile
 274# Installation targets should not require compiler. Unfortunately, vdso_install
 275# is an exception where build artifacts may be updated. This must be fixed.
 276no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
 277                        headers_install modules_install kernelrelease image_name
 278no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
 279                          image_name
 280single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
 281
 282config-build    :=
 283mixed-build     :=
 284need-config     := 1
 285need-compiler   := 1
 286may-sync-config := 1
 287single-build    :=
 288
 289ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
 290        ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
 291                need-config :=
 292        endif
 293endif
 294
 295ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
 296        ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
 297                need-compiler :=
 298        endif
 299endif
 300
 301ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
 302        ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
 303                may-sync-config :=
 304        endif
 305endif
 306
 307ifneq ($(KBUILD_EXTMOD),)
 308        may-sync-config :=
 309endif
 310
 311ifeq ($(KBUILD_EXTMOD),)
 312        ifneq ($(filter %config,$(MAKECMDGOALS)),)
 313                config-build := 1
 314                ifneq ($(words $(MAKECMDGOALS)),1)
 315                        mixed-build := 1
 316                endif
 317        endif
 318endif
 319
 320# We cannot build single targets and the others at the same time
 321ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
 322        single-build := 1
 323        ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
 324                mixed-build := 1
 325        endif
 326endif
 327
 328# For "make -j clean all", "make -j mrproper defconfig all", etc.
 329ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
 330        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
 331                mixed-build := 1
 332        endif
 333endif
 334
 335# install and modules_install need also be processed one by one
 336ifneq ($(filter install,$(MAKECMDGOALS)),)
 337        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
 338                mixed-build := 1
 339        endif
 340endif
 341
 342ifdef mixed-build
 343# ===========================================================================
 344# We're called with mixed targets (*config and build targets).
 345# Handle them one by one.
 346
 347PHONY += $(MAKECMDGOALS) __build_one_by_one
 348
 349$(MAKECMDGOALS): __build_one_by_one
 350        @:
 351
 352__build_one_by_one:
 353        $(Q)set -e; \
 354        for i in $(MAKECMDGOALS); do \
 355                $(MAKE) -f $(srctree)/Makefile $$i; \
 356        done
 357
 358else # !mixed-build
 359
 360include $(srctree)/scripts/Kbuild.include
 361
 362# Read KERNELRELEASE from include/config/kernel.release (if it exists)
 363KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
 364KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
 365export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
 366
 367include $(srctree)/scripts/subarch.include
 368
 369# Cross compiling and selecting different set of gcc/bin-utils
 370# ---------------------------------------------------------------------------
 371#
 372# When performing cross compilation for other architectures ARCH shall be set
 373# to the target architecture. (See arch/* for the possibilities).
 374# ARCH can be set during invocation of make:
 375# make ARCH=ia64
 376# Another way is to have ARCH set in the environment.
 377# The default ARCH is the host where make is executed.
 378
 379# CROSS_COMPILE specify the prefix used for all executables used
 380# during compilation. Only gcc and related bin-utils executables
 381# are prefixed with $(CROSS_COMPILE).
 382# CROSS_COMPILE can be set on the command line
 383# make CROSS_COMPILE=ia64-linux-
 384# Alternatively CROSS_COMPILE can be set in the environment.
 385# Default value for CROSS_COMPILE is not to prefix executables
 386# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
 387ARCH            ?= $(SUBARCH)
 388
 389# Architecture as present in compile.h
 390UTS_MACHINE     := $(ARCH)
 391SRCARCH         := $(ARCH)
 392
 393# Additional ARCH settings for x86
 394ifeq ($(ARCH),i386)
 395        SRCARCH := x86
 396endif
 397ifeq ($(ARCH),x86_64)
 398        SRCARCH := x86
 399endif
 400
 401# Additional ARCH settings for sparc
 402ifeq ($(ARCH),sparc32)
 403       SRCARCH := sparc
 404endif
 405ifeq ($(ARCH),sparc64)
 406       SRCARCH := sparc
 407endif
 408
 409# Additional ARCH settings for parisc
 410ifeq ($(ARCH),parisc64)
 411       SRCARCH := parisc
 412endif
 413
 414export cross_compiling :=
 415ifneq ($(SRCARCH),$(SUBARCH))
 416cross_compiling := 1
 417endif
 418
 419KCONFIG_CONFIG  ?= .config
 420export KCONFIG_CONFIG
 421
 422# SHELL used by kbuild
 423CONFIG_SHELL := sh
 424
 425HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
 426HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
 427HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
 428
 429ifneq ($(LLVM),)
 430ifneq ($(filter %/,$(LLVM)),)
 431LLVM_PREFIX := $(LLVM)
 432else ifneq ($(filter -%,$(LLVM)),)
 433LLVM_SUFFIX := $(LLVM)
 434endif
 435
 436HOSTCC  = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
 437HOSTCXX = $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
 438else
 439HOSTCC  = gcc
 440HOSTCXX = g++
 441endif
 442HOSTPKG_CONFIG  = pkg-config
 443
 444KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
 445                         -O2 -fomit-frame-pointer -std=gnu11 \
 446                         -Wdeclaration-after-statement
 447KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
 448KBUILD_USERLDFLAGS := $(USERLDFLAGS)
 449
 450KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
 451KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
 452KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
 453KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
 454
 455# Make variables (CC, etc...)
 456CPP             = $(CC) -E
 457ifneq ($(LLVM),)
 458CC              = $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
 459LD              = $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
 460AR              = $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
 461NM              = $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
 462OBJCOPY         = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
 463OBJDUMP         = $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
 464READELF         = $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
 465STRIP           = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
 466else
 467CC              = $(CROSS_COMPILE)gcc
 468LD              = $(CROSS_COMPILE)ld
 469AR              = $(CROSS_COMPILE)ar
 470NM              = $(CROSS_COMPILE)nm
 471OBJCOPY         = $(CROSS_COMPILE)objcopy
 472OBJDUMP         = $(CROSS_COMPILE)objdump
 473READELF         = $(CROSS_COMPILE)readelf
 474STRIP           = $(CROSS_COMPILE)strip
 475endif
 476PAHOLE          = pahole
 477RESOLVE_BTFIDS  = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
 478LEX             = flex
 479YACC            = bison
 480AWK             = awk
 481INSTALLKERNEL  := installkernel
 482DEPMOD          = depmod
 483PERL            = perl
 484PYTHON3         = python3
 485CHECK           = sparse
 486BASH            = bash
 487KGZIP           = gzip
 488KBZIP2          = bzip2
 489KLZOP           = lzop
 490LZMA            = lzma
 491LZ4             = lz4c
 492XZ              = xz
 493ZSTD            = zstd
 494
 495PAHOLE_FLAGS    = $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
 496
 497CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 498                  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 499NOSTDINC_FLAGS :=
 500CFLAGS_MODULE   =
 501AFLAGS_MODULE   =
 502LDFLAGS_MODULE  =
 503CFLAGS_KERNEL   =
 504AFLAGS_KERNEL   =
 505LDFLAGS_vmlinux =
 506
 507# Use USERINCLUDE when you must reference the UAPI directories only.
 508USERINCLUDE    := \
 509                -I$(srctree)/arch/$(SRCARCH)/include/uapi \
 510                -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
 511                -I$(srctree)/include/uapi \
 512                -I$(objtree)/include/generated/uapi \
 513                -include $(srctree)/include/linux/compiler-version.h \
 514                -include $(srctree)/include/linux/kconfig.h
 515
 516# Use LINUXINCLUDE when you must reference the include/ directory.
 517# Needed to be compatible with the O= option
 518LINUXINCLUDE    := \
 519                -I$(srctree)/arch/$(SRCARCH)/include \
 520                -I$(objtree)/arch/$(SRCARCH)/include/generated \
 521                $(if $(building_out_of_srctree),-I$(srctree)/include) \
 522                -I$(objtree)/include \
 523                $(USERINCLUDE)
 524
 525KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 526KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 527                   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 528                   -Werror=implicit-function-declaration -Werror=implicit-int \
 529                   -Werror=return-type -Wno-format-security \
 530                   -std=gnu11
 531KBUILD_CPPFLAGS := -D__KERNEL__
 532KBUILD_AFLAGS_KERNEL :=
 533KBUILD_CFLAGS_KERNEL :=
 534KBUILD_AFLAGS_MODULE  := -DMODULE
 535KBUILD_CFLAGS_MODULE  := -DMODULE
 536KBUILD_LDFLAGS_MODULE :=
 537KBUILD_LDFLAGS :=
 538CLANG_FLAGS :=
 539
 540export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
 541export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
 542export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
 543export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
 544export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 545export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
 546
 547export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 548export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 549export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 550export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 551export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
 552export PAHOLE_FLAGS
 553
 554# Files to ignore in find ... statements
 555
 556export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
 557                          -name CVS -o -name .pc -o -name .hg -o -name .git \) \
 558                          -prune -o
 559export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
 560                         --exclude CVS --exclude .pc --exclude .hg --exclude .git
 561
 562# ===========================================================================
 563# Rules shared between *config targets and build targets
 564
 565# Basic helpers built in scripts/basic/
 566PHONY += scripts_basic
 567scripts_basic:
 568        $(Q)$(MAKE) $(build)=scripts/basic
 569
 570PHONY += outputmakefile
 571ifdef building_out_of_srctree
 572# Before starting out-of-tree build, make sure the source tree is clean.
 573# outputmakefile generates a Makefile in the output directory, if using a
 574# separate output directory. This allows convenient use of make in the
 575# output directory.
 576# At the same time when output Makefile generated, generate .gitignore to
 577# ignore whole output directory
 578
 579quiet_cmd_makefile = GEN     Makefile
 580      cmd_makefile = { \
 581        echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
 582        echo "include $(srctree)/Makefile"; \
 583        } > Makefile
 584
 585outputmakefile:
 586        $(Q)if [ -f $(srctree)/.config -o \
 587                 -d $(srctree)/include/config -o \
 588                 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
 589                echo >&2 "***"; \
 590                echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
 591                echo >&2 "*** in $(abs_srctree)";\
 592                echo >&2 "***"; \
 593                false; \
 594        fi
 595        $(Q)ln -fsn $(srctree) source
 596        $(call cmd,makefile)
 597        $(Q)test -e .gitignore || \
 598        { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
 599endif
 600
 601# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
 602# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
 603# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
 604# and from include/config/auto.conf.cmd to detect the compiler upgrade.
 605CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
 606
 607ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
 608include $(srctree)/scripts/Makefile.clang
 609endif
 610
 611# Include this also for config targets because some architectures need
 612# cc-cross-prefix to determine CROSS_COMPILE.
 613ifdef need-compiler
 614include $(srctree)/scripts/Makefile.compiler
 615endif
 616
 617ifdef config-build
 618# ===========================================================================
 619# *config targets only - make sure prerequisites are updated, and descend
 620# in scripts/kconfig to make the *config target
 621
 622# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
 623# KBUILD_DEFCONFIG may point out an alternative default configuration
 624# used for 'make defconfig'
 625include $(srctree)/arch/$(SRCARCH)/Makefile
 626export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
 627
 628config: outputmakefile scripts_basic FORCE
 629        $(Q)$(MAKE) $(build)=scripts/kconfig $@
 630
 631%config: outputmakefile scripts_basic FORCE
 632        $(Q)$(MAKE) $(build)=scripts/kconfig $@
 633
 634else #!config-build
 635# ===========================================================================
 636# Build targets only - this includes vmlinux, arch specific targets, clean
 637# targets and others. In general all targets except *config targets.
 638
 639# If building an external module we do not care about the all: rule
 640# but instead __all depend on modules
 641PHONY += all
 642ifeq ($(KBUILD_EXTMOD),)
 643__all: all
 644else
 645__all: modules
 646endif
 647
 648# Decide whether to build built-in, modular, or both.
 649# Normally, just do built-in.
 650
 651KBUILD_MODULES :=
 652KBUILD_BUILTIN := 1
 653
 654# If we have only "make modules", don't compile built-in objects.
 655ifeq ($(MAKECMDGOALS),modules)
 656  KBUILD_BUILTIN :=
 657endif
 658
 659# If we have "make <whatever> modules", compile modules
 660# in addition to whatever we do anyway.
 661# Just "make" or "make all" shall build modules as well
 662
 663ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
 664  KBUILD_MODULES := 1
 665endif
 666
 667ifeq ($(MAKECMDGOALS),)
 668  KBUILD_MODULES := 1
 669endif
 670
 671export KBUILD_MODULES KBUILD_BUILTIN
 672
 673ifdef need-config
 674include include/config/auto.conf
 675endif
 676
 677ifeq ($(KBUILD_EXTMOD),)
 678# Objects we will link into vmlinux / subdirs we need to visit
 679core-y          := init/ usr/ arch/$(SRCARCH)/
 680drivers-y       := drivers/ sound/
 681drivers-$(CONFIG_SAMPLES) += samples/
 682drivers-$(CONFIG_NET) += net/
 683drivers-y       += virt/
 684libs-y          := lib/
 685endif # KBUILD_EXTMOD
 686
 687# The all: target is the default when no target is given on the
 688# command line.
 689# This allow a user to issue only 'make' to build a kernel including modules
 690# Defaults to vmlinux, but the arch makefile usually adds further targets
 691all: vmlinux
 692
 693CFLAGS_GCOV     := -fprofile-arcs -ftest-coverage
 694ifdef CONFIG_CC_IS_GCC
 695CFLAGS_GCOV     += -fno-tree-loop-im
 696endif
 697export CFLAGS_GCOV
 698
 699# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
 700ifdef CONFIG_FUNCTION_TRACER
 701  CC_FLAGS_FTRACE := -pg
 702endif
 703
 704include $(srctree)/arch/$(SRCARCH)/Makefile
 705
 706ifdef need-config
 707ifdef may-sync-config
 708# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
 709# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
 710# because some architectures define CROSS_COMPILE there.
 711include include/config/auto.conf.cmd
 712
 713$(KCONFIG_CONFIG):
 714        @echo >&2 '***'
 715        @echo >&2 '*** Configuration file "$@" not found!'
 716        @echo >&2 '***'
 717        @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
 718        @echo >&2 '*** "make menuconfig" or "make xconfig").'
 719        @echo >&2 '***'
 720        @/bin/false
 721
 722# The actual configuration files used during the build are stored in
 723# include/generated/ and include/config/. Update them if .config is newer than
 724# include/config/auto.conf (which mirrors .config).
 725#
 726# This exploits the 'multi-target pattern rule' trick.
 727# The syncconfig should be executed only once to make all the targets.
 728# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
 729#
 730# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
 731# so you cannot notice that Kconfig is waiting for the user input.
 732%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
 733        $(Q)$(kecho) "  SYNC    $@"
 734        $(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
 735else # !may-sync-config
 736# External modules and some install targets need include/generated/autoconf.h
 737# and include/config/auto.conf but do not care if they are up-to-date.
 738# Use auto.conf to trigger the test
 739PHONY += include/config/auto.conf
 740
 741include/config/auto.conf:
 742        $(Q)test -e include/generated/autoconf.h -a -e $@ || (          \
 743        echo >&2;                                                       \
 744        echo >&2 "  ERROR: Kernel configuration is invalid.";           \
 745        echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
 746        echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";      \
 747        echo >&2 ;                                                      \
 748        /bin/false)
 749
 750endif # may-sync-config
 751endif # need-config
 752
 753KBUILD_CFLAGS   += -fno-delete-null-pointer-checks
 754KBUILD_CFLAGS   += $(call cc-disable-warning,frame-address,)
 755KBUILD_CFLAGS   += $(call cc-disable-warning, format-truncation)
 756KBUILD_CFLAGS   += $(call cc-disable-warning, format-overflow)
 757KBUILD_CFLAGS   += $(call cc-disable-warning, address-of-packed-member)
 758
 759ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
 760KBUILD_CFLAGS += -O2
 761else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
 762KBUILD_CFLAGS += -Os
 763endif
 764
 765# Tell gcc to never replace conditional load with a non-conditional one
 766ifdef CONFIG_CC_IS_GCC
 767# gcc-10 renamed --param=allow-store-data-races=0 to
 768# -fno-allow-store-data-races.
 769KBUILD_CFLAGS   += $(call cc-option,--param=allow-store-data-races=0)
 770KBUILD_CFLAGS   += $(call cc-option,-fno-allow-store-data-races)
 771endif
 772
 773ifdef CONFIG_READABLE_ASM
 774# Disable optimizations that make assembler listings hard to read.
 775# reorder blocks reorders the control in the function
 776# ipa clone creates specialized cloned functions
 777# partial inlining inlines only parts of functions
 778KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
 779endif
 780
 781ifneq ($(CONFIG_FRAME_WARN),0)
 782KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
 783endif
 784
 785stackp-flags-y                                    := -fno-stack-protector
 786stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
 787stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
 788
 789KBUILD_CFLAGS += $(stackp-flags-y)
 790
 791KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
 792KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
 793KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
 794
 795ifdef CONFIG_CC_IS_CLANG
 796KBUILD_CPPFLAGS += -Qunused-arguments
 797# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
 798KBUILD_CFLAGS += -Wno-gnu
 799else
 800
 801# gcc inanely warns about local variables called 'main'
 802KBUILD_CFLAGS += -Wno-main
 803endif
 804
 805# These warnings generated too much noise in a regular build.
 806# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
 807KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 808KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 809
 810# These result in bogus false positives
 811KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
 812
 813ifdef CONFIG_FRAME_POINTER
 814KBUILD_CFLAGS   += -fno-omit-frame-pointer -fno-optimize-sibling-calls
 815else
 816# Some targets (ARM with Thumb2, for example), can't be built with frame
 817# pointers.  For those, we don't have FUNCTION_TRACER automatically
 818# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
 819# incompatible with -fomit-frame-pointer with current GCC, so we don't use
 820# -fomit-frame-pointer with FUNCTION_TRACER.
 821ifndef CONFIG_FUNCTION_TRACER
 822KBUILD_CFLAGS   += -fomit-frame-pointer
 823endif
 824endif
 825
 826# Initialize all stack variables with a 0xAA pattern.
 827ifdef CONFIG_INIT_STACK_ALL_PATTERN
 828KBUILD_CFLAGS   += -ftrivial-auto-var-init=pattern
 829endif
 830
 831# Initialize all stack variables with a zero value.
 832ifdef CONFIG_INIT_STACK_ALL_ZERO
 833KBUILD_CFLAGS   += -ftrivial-auto-var-init=zero
 834ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
 835# https://github.com/llvm/llvm-project/issues/44842
 836KBUILD_CFLAGS   += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 837endif
 838endif
 839
 840# While VLAs have been removed, GCC produces unreachable stack probes
 841# for the randomize_kstack_offset feature. Disable it for all compilers.
 842KBUILD_CFLAGS   += $(call cc-option, -fno-stack-clash-protection)
 843
 844# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
 845ifdef CONFIG_ZERO_CALL_USED_REGS
 846KBUILD_CFLAGS   += -fzero-call-used-regs=used-gpr
 847endif
 848
 849ifdef CONFIG_FUNCTION_TRACER
 850ifdef CONFIG_FTRACE_MCOUNT_USE_CC
 851  CC_FLAGS_FTRACE       += -mrecord-mcount
 852  ifdef CONFIG_HAVE_NOP_MCOUNT
 853    ifeq ($(call cc-option-yn, -mnop-mcount),y)
 854      CC_FLAGS_FTRACE   += -mnop-mcount
 855      CC_FLAGS_USING    += -DCC_USING_NOP_MCOUNT
 856    endif
 857  endif
 858endif
 859ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 860  CC_FLAGS_USING        += -DCC_USING_NOP_MCOUNT
 861endif
 862ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
 863  ifdef CONFIG_HAVE_C_RECORDMCOUNT
 864    BUILD_C_RECORDMCOUNT := y
 865    export BUILD_C_RECORDMCOUNT
 866  endif
 867endif
 868ifdef CONFIG_HAVE_FENTRY
 869  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
 870  ifeq ($(call cc-option-yn, -mfentry),y)
 871    CC_FLAGS_FTRACE     += -mfentry
 872    CC_FLAGS_USING      += -DCC_USING_FENTRY
 873  endif
 874endif
 875export CC_FLAGS_FTRACE
 876KBUILD_CFLAGS   += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
 877KBUILD_AFLAGS   += $(CC_FLAGS_USING)
 878endif
 879
 880# We trigger additional mismatches with less inlining
 881ifdef CONFIG_DEBUG_SECTION_MISMATCH
 882KBUILD_CFLAGS += -fno-inline-functions-called-once
 883endif
 884
 885ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
 886KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
 887LDFLAGS_vmlinux += --gc-sections
 888endif
 889
 890ifdef CONFIG_SHADOW_CALL_STACK
 891CC_FLAGS_SCS    := -fsanitize=shadow-call-stack
 892KBUILD_CFLAGS   += $(CC_FLAGS_SCS)
 893export CC_FLAGS_SCS
 894endif
 895
 896ifdef CONFIG_LTO_CLANG
 897ifdef CONFIG_LTO_CLANG_THIN
 898CC_FLAGS_LTO    := -flto=thin -fsplit-lto-unit
 899KBUILD_LDFLAGS  += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
 900else
 901CC_FLAGS_LTO    := -flto
 902endif
 903CC_FLAGS_LTO    += -fvisibility=hidden
 904
 905# Limit inlining across translation units to reduce binary size
 906KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
 907
 908# Check for frame size exceeding threshold during prolog/epilog insertion
 909# when using lld < 13.0.0.
 910ifneq ($(CONFIG_FRAME_WARN),0)
 911ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
 912KBUILD_LDFLAGS  += -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
 913endif
 914endif
 915endif
 916
 917ifdef CONFIG_LTO
 918KBUILD_CFLAGS   += -fno-lto $(CC_FLAGS_LTO)
 919KBUILD_AFLAGS   += -fno-lto
 920export CC_FLAGS_LTO
 921endif
 922
 923ifdef CONFIG_CFI_CLANG
 924CC_FLAGS_CFI    := -fsanitize=cfi \
 925                   -fsanitize-cfi-cross-dso \
 926                   -fno-sanitize-cfi-canonical-jump-tables \
 927                   -fno-sanitize-trap=cfi \
 928                   -fno-sanitize-blacklist
 929
 930ifdef CONFIG_CFI_PERMISSIVE
 931CC_FLAGS_CFI    += -fsanitize-recover=cfi
 932endif
 933
 934# If LTO flags are filtered out, we must also filter out CFI.
 935CC_FLAGS_LTO    += $(CC_FLAGS_CFI)
 936KBUILD_CFLAGS   += $(CC_FLAGS_CFI)
 937export CC_FLAGS_CFI
 938endif
 939
 940ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
 941KBUILD_CFLAGS += -falign-functions=64
 942endif
 943
 944# arch Makefile may override CC so keep this after arch Makefile is included
 945NOSTDINC_FLAGS += -nostdinc
 946
 947# warn about C99 declaration after statement
 948KBUILD_CFLAGS += -Wdeclaration-after-statement
 949
 950# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
 951KBUILD_CFLAGS += -Wvla
 952
 953# disable pointer signed / unsigned warnings in gcc 4.0
 954KBUILD_CFLAGS += -Wno-pointer-sign
 955
 956# In order to make sure new function cast mismatches are not introduced
 957# in the kernel (to avoid tripping CFI checking), the kernel should be
 958# globally built with -Wcast-function-type.
 959KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
 960
 961# disable stringop warnings in gcc 8+
 962KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 963
 964# We'll want to enable this eventually, but it's not going away for 5.7 at least
 965KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
 966
 967# Another good warning that we'll want to enable eventually
 968KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 969
 970# Enabled with W=2, disabled by default as noisy
 971ifdef CONFIG_CC_IS_GCC
 972KBUILD_CFLAGS += -Wno-maybe-uninitialized
 973endif
 974
 975ifdef CONFIG_CC_IS_GCC
 976# The allocators already balk at large sizes, so silence the compiler
 977# warnings for bounds checks involving those possible values. While
 978# -Wno-alloc-size-larger-than would normally be used here, earlier versions
 979# of gcc (<9.1) weirdly don't handle the option correctly when _other_
 980# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
 981# doesn't work (as it is documented to), silently resolving to "0" prior to
 982# version 9.1 (and producing an error more recently). Numeric values larger
 983# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
 984# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
 985# choice, we must perform a versioned check to disable this warning.
 986# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
 987KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
 988endif
 989
 990# disable invalid "can't wrap" optimizations for signed / pointers
 991KBUILD_CFLAGS   += -fno-strict-overflow
 992
 993# Make sure -fstack-check isn't enabled (like gentoo apparently did)
 994KBUILD_CFLAGS  += -fno-stack-check
 995
 996# conserve stack if available
 997ifdef CONFIG_CC_IS_GCC
 998KBUILD_CFLAGS   += -fconserve-stack
 999endif
1000

1001# Prohibit date/time macros, which would make the build non-deterministic
1002KBUILD_CFLAGS   += -Werror=date-time
1003
1004# enforce correct pointer usage
1005KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1006
1007# Require designated initializers for all marked structures
1008KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1009
1010# change __FILE__ to the relative path from the srctree
1011KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1012
1013# include additional Makefiles when needed
1014include-y                       := scripts/Makefile.extrawarn
1015include-$(CONFIG_DEBUG_INFO)    += scripts/Makefile.debug
1016include-$(CONFIG_KASAN)         += scripts/Makefile.kasan
1017include-$(CONFIG_KCSAN)         += scripts/Makefile.kcsan
1018include-$(CONFIG_UBSAN)         += scripts/Makefile.ubsan
1019include-$(CONFIG_KCOV)          += scripts/Makefile.kcov
1020include-$(CONFIG_RANDSTRUCT)    += scripts/Makefile.randstruct
1021include-$(CONFIG_GCC_PLUGINS)   += scripts/Makefile.gcc-plugins
1022
1023include $(addprefix $(srctree)/, $(include-y))
1024
1025# scripts/Makefile.gcc-plugins is intentionally included last.
1026# Do not add $(call cc-option,...) below this line. When you build the kernel
1027# from the clean source tree, the GCC plugins do not exist at this point.
1028
1029# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1030KBUILD_CPPFLAGS += $(KCPPFLAGS)
1031KBUILD_AFLAGS   += $(KAFLAGS)
1032KBUILD_CFLAGS   += $(KCFLAGS)
1033
1034KBUILD_LDFLAGS_MODULE += --build-id=sha1
1035LDFLAGS_vmlinux += --build-id=sha1
1036
1037KBUILD_LDFLAGS  += -z noexecstack
1038ifeq ($(CONFIG_LD_IS_BFD),y)
1039KBUILD_LDFLAGS  += $(call ld-option,--no-warn-rwx-segments)
1040endif
1041
1042ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1043LDFLAGS_vmlinux += $(call ld-option, -X,)
1044endif
1045
1046ifeq ($(CONFIG_RELR),y)
1047LDFLAGS_vmlinux += --pack-dyn-relocs=relr --use-android-relr-tags
1048endif
1049
1050# We never want expected sections to be placed heuristically by the
1051# linker. All sections should be explicitly named in the linker script.
1052ifdef CONFIG_LD_ORPHAN_WARN
1053LDFLAGS_vmlinux += --orphan-handling=warn
1054endif
1055
1056# Align the bit size of userspace programs with the kernel
1057KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1058KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1059
1060# make the checker run with the right architecture
1061CHECKFLAGS += --arch=$(ARCH)
1062
1063# insure the checker run with the right endianness
1064CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1065
1066# the checker needs the correct machine size
1067CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1068
1069# Default kernel image to build when no specific target is given.
1070# KBUILD_IMAGE may be overruled on the command line or
1071# set in the environment
1072# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1073# this default value
1074export KBUILD_IMAGE ?= vmlinux
1075
1076#
1077# INSTALL_PATH specifies where to place the updated kernel and system map
1078# images. Default is /boot, but you can set it to other values
1079export  INSTALL_PATH ?= /boot
1080
1081#
1082# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1083# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1084# an argument if needed. Otherwise it defaults to the kernel install path
1085#
1086export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1087
1088#
1089# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1090# relocations required by build roots.  This is not defined in the
1091# makefile but the argument can be passed to make if needed.
1092#
1093
1094MODLIB  = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1095export MODLIB
1096
1097PHONY += prepare0
1098
1099export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1100export MODORDER := $(extmod_prefix)modules.order
1101export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1102
1103ifeq ($(KBUILD_EXTMOD),)
1104core-y                  += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
1105core-$(CONFIG_BLOCK)    += block/
1106core-$(CONFIG_IO_URING) += io_uring/
1107
1108vmlinux-dirs    := $(patsubst %/,%,$(filter %/, \
1109                     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1110                     $(libs-y) $(libs-m)))
1111
1112vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1113                     $(patsubst %/,%,$(filter %/, $(core-) \
1114                        $(drivers-) $(libs-))))
1115
1116build-dirs      := $(vmlinux-dirs)
1117clean-dirs      := $(vmlinux-alldirs)
1118
1119subdir-modorder := $(addsuffix /modules.order, $(build-dirs))
1120
1121# Externally visible symbols (used by link-vmlinux.sh)
1122KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1123KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1124ifdef CONFIG_MODULES
1125KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1126KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1127else
1128KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1129endif
1130KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1131
1132export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1133export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1134# used by scripts/Makefile.package
1135export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1136
1137vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1138
1139# Recurse until adjust_autoksyms.sh is satisfied
1140PHONY += autoksyms_recursive
1141ifdef CONFIG_TRIM_UNUSED_KSYMS
1142# For the kernel to actually contain only the needed exported symbols,
1143# we have to build modules as well to determine what those symbols are.
1144# (this can be evaluated only once include/config/auto.conf has been included)
1145KBUILD_MODULES := 1
1146
1147autoksyms_recursive: descend modules.order
1148        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1149          "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
1150endif
1151
1152autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1153
1154quiet_cmd_autoksyms_h = GEN     $@
1155      cmd_autoksyms_h = mkdir -p $(dir $@); \
1156                        $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1157
1158$(autoksyms_h):
1159        $(call cmd,autoksyms_h)
1160
1161ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1162
1163# Final link of vmlinux with optional arch pass after final link
1164cmd_link-vmlinux =                                                 \
1165        $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1166        $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1167
1168vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1169        +$(call if_changed_dep,link-vmlinux)
1170
1171targets := vmlinux
1172
1173# The actual objects are generated when descending,
1174# make sure no implicit rule kicks in
1175$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1176
1177filechk_kernel.release = \
1178        echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1179
1180# Store (new) KERNELRELEASE string in include/config/kernel.release
1181include/config/kernel.release: FORCE
1182        $(call filechk,kernel.release)
1183
1184# Additional helpers built in scripts/
1185# Carefully list dependencies so we do not try to build scripts twice
1186# in parallel
1187PHONY += scripts
1188scripts: scripts_basic scripts_dtc
1189        $(Q)$(MAKE) $(build)=$(@)
1190
1191# Things we need to do before we recursively start building the kernel
1192# or the modules are listed in "prepare".
1193# A multi level approach is used. prepareN is processed before prepareN-1.
1194# archprepare is used in arch Makefiles and when processed asm symlink,
1195# version.h and scripts_basic is processed / created.
1196
1197PHONY += prepare archprepare
1198
1199archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1200        asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1201        include/generated/autoconf.h remove-stale-files
1202
1203prepare0: archprepare
1204        $(Q)$(MAKE) $(build)=scripts/mod
1205        $(Q)$(MAKE) $(build)=.
1206
1207# All the preparing..
1208prepare: prepare0
1209
1210PHONY += remove-stale-files
1211remove-stale-files:
1212        $(Q)$(srctree)/scripts/remove-stale-files
1213
1214# Support for using generic headers in asm-generic
1215asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1216
1217PHONY += asm-generic uapi-asm-generic
1218asm-generic: uapi-asm-generic
1219        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1220        generic=include/asm-generic
1221uapi-asm-generic:
1222        $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1223        generic=include/uapi/asm-generic
1224
1225# Generate some files
1226# ---------------------------------------------------------------------------
1227
1228# KERNELRELEASE can change from a few different places, meaning version.h
1229# needs to be updated, so this check is forced on all builds
1230
1231uts_len := 64
1232define filechk_utsrelease.h
1233        if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1234          echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1235          exit 1;                                                         \
1236        fi;                                                               \
1237        echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1238endef
1239
1240define filechk_version.h
1241        if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1242                echo \#define LINUX_VERSION_CODE $(shell                 \
1243                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1244        else                                                             \
1245                echo \#define LINUX_VERSION_CODE $(shell                 \
1246                expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1247        fi;                                                              \
1248        echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1249        ((c) > 255 ? 255 : (c)))';                                       \
1250        echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1251        echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1252        echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1253endef
1254
1255$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1256$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1257$(version_h): FORCE
1258        $(call filechk,version.h)
1259
1260include/generated/utsrelease.h: include/config/kernel.release FORCE
1261        $(call filechk,utsrelease.h)
1262
1263PHONY += headerdep
1264headerdep:
1265        $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1266        $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1267
1268# ---------------------------------------------------------------------------
1269# Kernel headers
1270
1271#Default location for installed headers
1272export INSTALL_HDR_PATH = $(objtree)/usr
1273
1274quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1275      cmd_headers_install = \
1276        mkdir -p $(INSTALL_HDR_PATH); \
1277        rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1278        usr/include $(INSTALL_HDR_PATH)
1279
1280PHONY += headers_install
1281headers_install: headers
1282        $(call cmd,headers_install)
1283
1284PHONY += archheaders archscripts
1285
1286hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1287
1288PHONY += headers
1289headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1290        $(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1291        $(Q)$(MAKE) $(hdr-inst)=include/uapi
1292        $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1293
1294ifdef CONFIG_HEADERS_INSTALL
1295prepare: headers
1296endif
1297
1298PHONY += scripts_unifdef
1299scripts_unifdef: scripts_basic
1300        $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1301
1302# ---------------------------------------------------------------------------
1303# Install
1304
1305# Many distributions have the custom install script, /sbin/installkernel.
1306# If DKMS is installed, 'make install' will eventually recurse back
1307# to this Makefile to build and install external modules.
1308# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1309
1310quiet_cmd_install = INSTALL $(INSTALL_PATH)
1311      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1312
1313# ---------------------------------------------------------------------------
1314# Tools
1315
1316ifdef CONFIG_OBJTOOL
1317prepare: tools/objtool
1318endif
1319
1320ifdef CONFIG_BPF
1321ifdef CONFIG_DEBUG_INFO_BTF
1322prepare: tools/bpf/resolve_btfids
1323endif
1324endif
1325
1326PHONY += resolve_btfids_clean
1327
1328resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1329
1330# tools/bpf/resolve_btfids directory might not exist
1331# in output directory, skip its clean in that case
1332resolve_btfids_clean:
1333ifneq ($(wildcard $(resolve_btfids_O)),)
1334        $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1335endif
1336
1337# Clear a bunch of variables before executing the submake
1338ifeq ($(quiet),silent_)
1339tools_silent=s
1340endif
1341
1342tools/: FORCE
1343        $(Q)mkdir -p $(objtree)/tools
1344        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1345
1346tools/%: FORCE
1347        $(Q)mkdir -p $(objtree)/tools
1348        $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1349
1350# ---------------------------------------------------------------------------
1351# Kernel selftest
1352
1353PHONY += kselftest
1354kselftest: headers
1355        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1356
1357kselftest-%: headers FORCE
1358        $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1359
1360PHONY += kselftest-merge
1361kselftest-merge:
1362        $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1363        $(Q)find $(srctree)/tools/testing/selftests -name config | \
1364                xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1365        $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1366
1367# ---------------------------------------------------------------------------
1368# Devicetree files
1369
1370ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1371dtstree := arch/$(SRCARCH)/boot/dts
1372endif
1373
1374ifneq ($(dtstree),)
1375
1376%.dtb: dtbs_prepare
1377        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1378
1379%.dtbo: dtbs_prepare
1380        $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1381
1382PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1383dtbs: dtbs_prepare
1384        $(Q)$(MAKE) $(build)=$(dtstree)
1385
1386# include/config/kernel.release is actually needed when installing DTBs because
1387# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1388# dtbs_install depend on it as dtbs_install may run as root.
1389dtbs_prepare: include/config/kernel.release scripts_dtc
1390
1391ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1392export CHECK_DTBS=y
1393dtbs: dt_binding_check
1394endif
1395
1396dtbs_check: dtbs
1397
1398dtbs_install:
1399        $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1400
1401ifdef CONFIG_OF_EARLY_FLATTREE
1402all: dtbs
1403endif
1404
1405endif
1406
1407PHONY += scripts_dtc
1408scripts_dtc: scripts_basic
1409        $(Q)$(MAKE) $(build)=scripts/dtc
1410
1411ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1412export CHECK_DT_BINDING=y
1413endif
1414
1415PHONY += dt_binding_check
1416dt_binding_check: scripts_dtc
1417        $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1418
1419# ---------------------------------------------------------------------------
1420# Modules
1421
1422ifdef CONFIG_MODULES
1423
1424# By default, build modules as well
1425
1426all: modules
1427
1428# When we're building modules with modversions, we need to consider
1429# the built-in objects during the descend as well, in order to
1430# make sure the checksums are up to date before we record them.
1431ifdef CONFIG_MODVERSIONS
1432  KBUILD_BUILTIN := 1
1433endif
1434
1435# Build modules
1436#
1437# A module can be listed more than once in obj-m resulting in
1438# duplicate lines in modules.order files.  Those are removed
1439# using awk while concatenating to the final file.
1440
1441PHONY += modules
1442modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1443
1444cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1445
1446modules.order: $(subdir-modorder) FORCE
1447        $(call if_changed,modules_order)
1448
1449targets += modules.order
1450
1451# Target to prepare building external modules
1452PHONY += modules_prepare
1453modules_prepare: prepare
1454        $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1455
1456export modules_sign_only :=
1457
1458ifeq ($(CONFIG_MODULE_SIG),y)
1459PHONY += modules_sign
1460modules_sign: modules_install
1461        @:
1462
1463# modules_sign is a subset of modules_install.
1464# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1465ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1466modules_sign_only := y
1467endif
1468endif
1469
1470modinst_pre :=
1471ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1472modinst_pre := __modinst_pre
1473endif
1474
1475modules_install: $(modinst_pre)
1476PHONY += __modinst_pre
1477__modinst_pre:
1478        @rm -rf $(MODLIB)/kernel
1479        @rm -f $(MODLIB)/source
1480        @mkdir -p $(MODLIB)/kernel
1481        @ln -s $(abspath $(srctree)) $(MODLIB)/source
1482        @if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1483                rm -f $(MODLIB)/build ; \
1484                ln -s $(CURDIR) $(MODLIB)/build ; \
1485        fi
1486        @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1487        @cp -f modules.builtin $(MODLIB)/
1488        @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1489
1490endif # CONFIG_MODULES
1491
1492###
1493# Cleaning is done on three levels.
1494# make clean     Delete most generated files
1495#                Leave enough to build external modules
1496# make mrproper  Delete the current configuration, and all generated files
1497# make distclean Remove editor backup files, patch leftover files and the like
1498
1499# Directories & files removed with 'make clean'
1500CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1501               modules.builtin modules.builtin.modinfo modules.nsdeps \
1502               compile_commands.json .thinlto-cache
1503
1504# Directories & files removed with 'make mrproper'
1505MRPROPER_FILES += include/config include/generated          \
1506                  arch/$(SRCARCH)/include/generated .objdiff \
1507                  debian snap tar-install \
1508                  .config .config.old .version \
1509                  Module.symvers \
1510                  certs/signing_key.pem \
1511                  certs/x509.genkey \
1512                  vmlinux-gdb.py \
1513                  *.spec
1514
1515# clean - Delete most, but leave enough to build external modules
1516#
1517clean: rm-files := $(CLEAN_FILES)
1518
1519PHONY += archclean vmlinuxclean
1520
1521vmlinuxclean:
1522        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1523        $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1524
1525clean: archclean vmlinuxclean resolve_btfids_clean
1526
1527# mrproper - Delete all generated files, including .config
1528#
1529mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1530mrproper-dirs      := $(addprefix _mrproper_,scripts)
1531
1532PHONY += $(mrproper-dirs) mrproper
1533$(mrproper-dirs):
1534        $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1535
1536mrproper: clean $(mrproper-dirs)
1537        $(call cmd,rmfiles)
1538
1539# distclean
1540#
1541PHONY += distclean
1542
1543distclean: mrproper
1544        @find . $(RCS_FIND_IGNORE) \
1545                \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1546                -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1547                -o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1548                -o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1549                -type f -print | xargs rm -f
1550
1551
1552# Packaging of the kernel to various formats
1553# ---------------------------------------------------------------------------
1554
1555%src-pkg: FORCE
1556        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1557%pkg: include/config/kernel.release FORCE
1558        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1559
1560# Brief documentation of the typical targets used
1561# ---------------------------------------------------------------------------
1562
1563boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1564boards := $(sort $(notdir $(boards)))
1565board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1566board-dirs := $(sort $(notdir $(board-dirs:/=)))
1567
1568PHONY += help
1569help:
1570        @echo  'Cleaning targets:'
1571        @echo  '  clean           - Remove most generated files but keep the config and'
1572        @echo  '                    enough build support to build external modules'
1573        @echo  '  mrproper        - Remove all generated files + config + various backup files'
1574        @echo  '  distclean       - mrproper + remove editor backup and patch files'
1575        @echo  ''
1576        @echo  'Configuration targets:'
1577        @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1578        @echo  ''
1579        @echo  'Other generic targets:'
1580        @echo  '  all             - Build all targets marked with [*]'
1581        @echo  '* vmlinux         - Build the bare kernel'
1582        @echo  '* modules         - Build all modules'
1583        @echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1584        @echo  '  dir/            - Build all files in dir and below'
1585        @echo  '  dir/file.[ois]  - Build specified target only'
1586        @echo  '  dir/file.ll     - Build the LLVM assembly file'
1587        @echo  '                    (requires compiler support for LLVM assembly generation)'
1588        @echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1589        @echo  '                    (requires a recent binutils and recent build (System.map))'
1590        @echo  '  dir/file.ko     - Build module including final link'
1591        @echo  '  modules_prepare - Set up for building external modules'
1592        @echo  '  tags/TAGS       - Generate tags file for editors'
1593        @echo  '  cscope          - Generate cscope index'
1594        @echo  '  gtags           - Generate GNU GLOBAL index'
1595        @echo  '  kernelrelease   - Output the release version string (use with make -s)'
1596        @echo  '  kernelversion   - Output the version stored in Makefile (use with make -s)'
1597        @echo  '  image_name      - Output the image name (use with make -s)'
1598        @echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1599         echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1600         echo  ''
1601        @echo  'Static analysers:'
1602        @echo  '  checkstack      - Generate a list of stack hogs'
1603        @echo  '  versioncheck    - Sanity check on version.h usage'
1604        @echo  '  includecheck    - Check for duplicate included header files'
1605        @echo  '  export_report   - List the usages of all exported symbols'
1606        @echo  '  headerdep       - Detect inclusion cycles in headers'
1607        @echo  '  coccicheck      - Check with Coccinelle'
1608        @echo  '  clang-analyzer  - Check with clang static analyzer'
1609        @echo  '  clang-tidy      - Check with clang-tidy'
1610        @echo  ''
1611        @echo  'Tools:'
1612        @echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1613        @echo  ''
1614        @echo  'Kernel selftest:'
1615        @echo  '  kselftest         - Build and run kernel selftest'
1616        @echo  '                      Build, install, and boot kernel before'
1617        @echo  '                      running kselftest on it'
1618        @echo  '                      Run as root for full coverage'
1619        @echo  '  kselftest-all     - Build kernel selftest'
1620        @echo  '  kselftest-install - Build and install kernel selftest'
1621        @echo  '  kselftest-clean   - Remove all generated kselftest files'
1622        @echo  '  kselftest-merge   - Merge all the config dependencies of'
1623        @echo  '                      kselftest to existing .config.'
1624        @echo  ''
1625        @$(if $(dtstree), \
1626                echo 'Devicetree:'; \
1627                echo '* dtbs             - Build device tree blobs for enabled boards'; \
1628                echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1629                echo '  dt_binding_check - Validate device tree binding documents'; \
1630                echo '  dtbs_check       - Validate device tree source files';\
1631                echo '')
1632
1633        @echo 'Userspace tools targets:'
1634        @echo '  use "make tools/help"'
1635        @echo '  or  "cd tools; make help"'
1636        @echo  ''
1637        @echo  'Kernel packaging:'
1638        @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1639        @echo  ''
1640        @echo  'Documentation targets:'
1641        @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1642        @echo  ''
1643        @echo  'Architecture specific targets ($(SRCARCH)):'
1644        @$(or $(archhelp),\
1645                echo '  No architecture specific help defined for $(SRCARCH)')
1646        @echo  ''
1647        @$(if $(boards), \
1648                $(foreach b, $(boards), \
1649                printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1650                echo '')
1651        @$(if $(board-dirs), \
1652                $(foreach b, $(board-dirs), \
1653                printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1654                printf "  %-16s - Show all of the above\\n" help-boards; \
1655                echo '')
1656
1657        @echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1658        @echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1659        @echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1660        @echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1661        @echo  '                       (sparse by default)'
1662        @echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1663        @echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1664        @echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1665        @echo  '                1: warnings which may be relevant and do not occur too often'
1666        @echo  '                2: warnings which occur quite often but may still be relevant'
1667        @echo  '                3: more obscure warnings, can most likely be ignored'
1668        @echo  '                e: warnings are being treated as errors'
1669        @echo  '                Multiple levels can be combined with W=12 or W=123'
1670        @echo  ''
1671        @echo  'Execute "make" or "make all" to build all targets marked with [*] '
1672        @echo  'For further info see the ./README file'
1673
1674
1675help-board-dirs := $(addprefix help-,$(board-dirs))
1676
1677help-boards: $(help-board-dirs)
1678
1679boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1680
1681$(help-board-dirs): help-%:
1682        @echo  'Architecture specific targets ($(SRCARCH) $*):'
1683        @$(if $(boards-per-dir), \
1684                $(foreach b, $(boards-per-dir), \
1685                printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1686                echo '')
1687
1688
1689# Documentation targets
1690# ---------------------------------------------------------------------------
1691DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1692               linkcheckdocs dochelp refcheckdocs
1693PHONY += $(DOC_TARGETS)
1694$(DOC_TARGETS):
1695        $(Q)$(MAKE) $(build)=Documentation $@
1696
1697# Misc
1698# ---------------------------------------------------------------------------
1699
1700PHONY += scripts_gdb
1701scripts_gdb: prepare0
1702        $(Q)$(MAKE) $(build)=scripts/gdb
1703        $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1704
1705ifdef CONFIG_GDB_SCRIPTS
1706all: scripts_gdb
1707endif
1708
1709else # KBUILD_EXTMOD
1710
1711###
1712# External module support.
1713# When building external modules the kernel used as basis is considered
1714# read-only, and no consistency checks are made and the make
1715# system is not used on the basis kernel. If updates are required
1716# in the basis kernel ordinary make commands (without M=...) must be used.
1717
1718# We are always building only modules.
1719KBUILD_BUILTIN :=
1720KBUILD_MODULES := 1
1721
1722build-dirs := $(KBUILD_EXTMOD)
1723$(MODORDER): descend
1724        @:
1725
1726compile_commands.json: $(extmod_prefix)compile_commands.json
1727PHONY += compile_commands.json
1728
1729clean-dirs := $(KBUILD_EXTMOD)
1730clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1731        $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1732
1733PHONY += prepare
1734# now expand this into a simple variable to reduce the cost of shell evaluations
1735prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1736prepare:
1737        @if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1738                echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1739                echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1740                echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1741        fi
1742
1743PHONY += help
1744help:
1745        @echo  '  Building external modules.'
1746        @echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1747        @echo  ''
1748        @echo  '  modules         - default target, build the module(s)'
1749        @echo  '  modules_install - install the module'
1750        @echo  '  clean           - remove generated files in module directory only'
1751        @echo  ''
1752
1753# no-op for external module builds
1754PHONY += modules_prepare
1755
1756endif # KBUILD_EXTMOD
1757
1758# ---------------------------------------------------------------------------
1759# Modules
1760
1761PHONY += modules modules_install
1762
1763ifdef CONFIG_MODULES
1764
1765modules: modules_check
1766        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1767
1768PHONY += modules_check
1769modules_check: $(MODORDER)
1770        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1771
1772quiet_cmd_depmod = DEPMOD  $(MODLIB)
1773      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1774                   $(KERNELRELEASE)
1775
1776modules_install:
1777        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1778        $(call cmd,depmod)
1779
1780else # CONFIG_MODULES
1781
1782# Modules not configured
1783# ---------------------------------------------------------------------------
1784
1785modules modules_install:
1786        @echo >&2 '***'
1787        @echo >&2 '*** The present kernel configuration has modules disabled.'
1788        @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1789        @echo >&2 '*** to enable CONFIG_MODULES.'
1790        @echo >&2 '***'
1791        @exit 1
1792
1793endif # CONFIG_MODULES
1794
1795# Single targets
1796# ---------------------------------------------------------------------------
1797# To build individual files in subdirectories, you can do like this:
1798#
1799#   make foo/bar/baz.s
1800#
1801# The supported suffixes for single-target are listed in 'single-targets'
1802#
1803# To build only under specific subdirectories, you can do like this:
1804#
1805#   make foo/bar/baz/
1806
1807ifdef single-build
1808
1809# .ko is special because modpost is needed
1810single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1811single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1812                $(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1813
1814$(single-ko): single_modpost
1815        @:
1816$(single-no-ko): descend
1817        @:
1818
1819ifeq ($(KBUILD_EXTMOD),)
1820# For the single build of in-tree modules, use a temporary file to avoid
1821# the situation of modules_install installing an invalid modules.order.
1822MODORDER := .modules.tmp
1823endif
1824
1825PHONY += single_modpost
1826single_modpost: $(single-no-ko) modules_prepare
1827        $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1828        $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1829
1830KBUILD_MODULES := 1
1831
1832export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1833
1834# trim unrelated directories
1835build-dirs := $(foreach d, $(build-dirs), \
1836                        $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1837
1838endif
1839
1840ifndef CONFIG_MODULES
1841KBUILD_MODULES :=
1842endif
1843
1844# Handle descending into subdirectories listed in $(build-dirs)
1845# Preset locale variables to speed up the build process. Limit locale
1846# tweaks to this spot to avoid wrong language settings when running
1847# make menuconfig etc.
1848# Error messages still appears in the original language
1849PHONY += descend $(build-dirs)
1850descend: $(build-dirs)
1851$(build-dirs): prepare
1852        $(Q)$(MAKE) $(build)=$@ \
1853        single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1854        need-builtin=1 need-modorder=1
1855
1856clean-dirs := $(addprefix _clean_, $(clean-dirs))
1857PHONY += $(clean-dirs) clean
1858$(clean-dirs):
1859        $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1860
1861clean: $(clean-dirs)
1862        $(call cmd,rmfiles)
1863        @find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1864                \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1865                -o -name '*.ko.*' \
1866                -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1867                -o -name '*.dwo' -o -name '*.lst' \
1868                -o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
1869                -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1870                -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1871                -o -name '*.asn1.[ch]' \
1872                -o -name '*.symtypes' -o -name 'modules.order' \
1873                -o -name '.tmp_*' \
1874                -o -name '*.c.[012]*.*' \
1875                -o -name '*.ll' \
1876                -o -name '*.gcno' \
1877                -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1878
1879# Generate tags for editors
1880# ---------------------------------------------------------------------------
1881quiet_cmd_tags = GEN     $@
1882      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1883
1884tags TAGS cscope gtags: FORCE
1885        $(call cmd,tags)
1886
1887# Script to generate missing namespace dependencies
1888# ---------------------------------------------------------------------------
1889
1890PHONY += nsdeps
1891nsdeps: export KBUILD_NSDEPS=1
1892nsdeps: modules
1893        $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1894
1895# Clang Tooling
1896# ---------------------------------------------------------------------------
1897
1898quiet_cmd_gen_compile_commands = GEN     $@
1899      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1900
1901$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1902        $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1903        $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1904        $(call if_changed,gen_compile_commands)
1905
1906targets += $(extmod_prefix)compile_commands.json
1907
1908PHONY += clang-tidy clang-analyzer
1909
1910ifdef CONFIG_CC_IS_CLANG
1911quiet_cmd_clang_tools = CHECK   $<
1912      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1913
1914clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1915        $(call cmd,clang_tools)
1916else
1917clang-tidy clang-analyzer:
1918        @echo "$@ requires CC=clang" >&2
1919        @false
1920endif
1921
1922# Scripts to check various things for consistency
1923# ---------------------------------------------------------------------------
1924
1925PHONY += includecheck versioncheck coccicheck export_report
1926
1927includecheck:
1928        find $(srctree)/* $(RCS_FIND_IGNORE) \
1929                -name '*.[hcS]' -type f -print | sort \
1930                | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1931
1932versioncheck:
1933        find $(srctree)/* $(RCS_FIND_IGNORE) \
1934                -name '*.[hcS]' -type f -print | sort \
1935                | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1936
1937coccicheck:
1938        $(Q)$(BASH) $(srctree)/scripts/$@
1939
1940export_report:
1941        $(PERL) $(srctree)/scripts/export_report.pl
1942
1943PHONY += checkstack kernelrelease kernelversion image_name
1944
1945# UML needs a little special treatment here.  It wants to use the host
1946# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1947# else wants $(ARCH), including people doing cross-builds, which means
1948# that $(SUBARCH) doesn't work here.
1949ifeq ($(ARCH), um)
1950CHECKSTACK_ARCH := $(SUBARCH)
1951else
1952CHECKSTACK_ARCH := $(ARCH)
1953endif
1954checkstack:
1955        $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1956        $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1957
1958kernelrelease:
1959        @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1960
1961kernelversion:
1962        @echo $(KERNELVERSION)
1963
1964image_name:
1965        @echo $(KBUILD_IMAGE)
1966
1967quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1968      cmd_rmfiles = rm -rf $(rm-files)
1969
1970# read saved command lines for existing targets
1971existing-targets := $(wildcard $(sort $(targets)))
1972
1973-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1974
1975endif # config-build
1976endif # mixed-build
1977endif # need-sub-make
1978
1979PHONY += FORCE
1980FORCE:
1981
1982# Declare the contents of the PHONY variable as phony.  We keep that
1983# information in a variable so we can use it in if_changed and friends.
1984.PHONY: $(PHONY)
1985