xref: /linux/Makefile (revision bef83245f5ed434932aaf07f890142b576dc5d85)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 12
4SUBLEVEL = 0
5EXTRAVERSION = -rc2
6NAME = Baby Opossum Posse
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
14ifeq ($(filter output-sync,$(.FEATURES)),)
15$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41this-makefile := $(lastword $(MAKEFILE_LIST))
42abs_srctree := $(realpath $(dir $(this-makefile)))
43abs_objtree := $(CURDIR)
44
45ifneq ($(sub_make_done),1)
46
47# Do not use make's built-in rules and variables
48# (this increases performance and avoids hard-to-debug behaviour)
49MAKEFLAGS += -rR
50
51# Avoid funny character set dependencies
52unexport LC_ALL
53LC_COLLATE=C
54LC_NUMERIC=C
55export LC_COLLATE LC_NUMERIC
56
57# Avoid interference with shell env settings
58unexport GREP_OPTIONS
59
60# Beautify output
61# ---------------------------------------------------------------------------
62#
63# Most of build commands in Kbuild start with "cmd_". You can optionally define
64# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
65# that command is printed by default.
66#
67# e.g.)
68#    quiet_cmd_depmod = DEPMOD  $(MODLIB)
69#          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
70#
71# A simple variant is to prefix commands with $(Q) - that's useful
72# for commands that shall be hidden in non-verbose mode.
73#
74#    $(Q)$(MAKE) $(build)=scripts/basic
75#
76# If KBUILD_VERBOSE contains 1, the whole command is echoed.
77# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
78#
79# To put more focus on warnings, be less verbose as default
80# Use 'make V=1' to see the full commands
81
82ifeq ("$(origin V)", "command line")
83  KBUILD_VERBOSE = $(V)
84endif
85
86quiet = quiet_
87Q = @
88
89ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
90  quiet =
91  Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),)
97quiet=silent_
98override KBUILD_VERBOSE :=
99endif
100
101export quiet Q KBUILD_VERBOSE
102
103# Call a source code checker (by default, "sparse") as part of the
104# C compilation.
105#
106# Use 'make C=1' to enable checking of only re-compiled files.
107# Use 'make C=2' to enable checking of *all* source files, regardless
108# of whether they are re-compiled or not.
109#
110# See the file "Documentation/dev-tools/sparse.rst" for more details,
111# including where to get the "sparse" utility.
112
113ifeq ("$(origin C)", "command line")
114  KBUILD_CHECKSRC = $(C)
115endif
116ifndef KBUILD_CHECKSRC
117  KBUILD_CHECKSRC = 0
118endif
119
120export KBUILD_CHECKSRC
121
122# Enable "clippy" (a linter) as part of the Rust compilation.
123#
124# Use 'make CLIPPY=1' to enable it.
125ifeq ("$(origin CLIPPY)", "command line")
126  KBUILD_CLIPPY := $(CLIPPY)
127endif
128
129export KBUILD_CLIPPY
130
131# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
132# directory of external module to build. Setting M= takes precedence.
133ifeq ("$(origin M)", "command line")
134  KBUILD_EXTMOD := $(M)
135endif
136
137$(if $(word 2, $(KBUILD_EXTMOD)), \
138	$(error building multiple external modules is not supported))
139
140$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
141	$(error module directory path cannot contain '$x')))
142
143# Remove trailing slashes
144ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
145KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
146endif
147
148export KBUILD_EXTMOD
149
150# backward compatibility
151KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
152
153ifeq ("$(origin W)", "command line")
154  KBUILD_EXTRA_WARN := $(W)
155endif
156
157export KBUILD_EXTRA_WARN
158
159# Kbuild will save output files in the current working directory.
160# This does not need to match to the root of the kernel source tree.
161#
162# For example, you can do this:
163#
164#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
165#
166# If you want to save output files in a different location, there are
167# two syntaxes to specify it.
168#
169# 1) O=
170# Use "make O=dir/to/store/output/files/"
171#
172# 2) Set KBUILD_OUTPUT
173# Set the environment variable KBUILD_OUTPUT to point to the output directory.
174# export KBUILD_OUTPUT=dir/to/store/output/files/; make
175#
176# The O= assignment takes precedence over the KBUILD_OUTPUT environment
177# variable.
178
179# Do we want to change the working directory?
180ifeq ("$(origin O)", "command line")
181  KBUILD_OUTPUT := $(O)
182endif
183
184ifneq ($(KBUILD_OUTPUT),)
185# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
186$(shell mkdir -p "$(KBUILD_OUTPUT)")
187# $(realpath ...) resolves symlinks
188abs_objtree := $(realpath $(KBUILD_OUTPUT))
189$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)"))
190endif # ifneq ($(KBUILD_OUTPUT),)
191
192ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
193$(error source directory cannot contain spaces or colons)
194endif
195
196export sub_make_done := 1
197
198endif # sub_make_done
199
200ifeq ($(abs_objtree),$(CURDIR))
201# Suppress "Entering directory ..." if we are at the final work directory.
202no-print-directory := --no-print-directory
203else
204# Recursion to show "Entering directory ..."
205need-sub-make := 1
206endif
207
208ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
209# If --no-print-directory is unset, recurse once again to set it.
210# You may end up recursing into __sub-make twice. This is needed due to the
211# behavior change in GNU Make 4.4.1.
212need-sub-make := 1
213endif
214
215ifeq ($(need-sub-make),1)
216
217PHONY += $(MAKECMDGOALS) __sub-make
218
219$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
220	@:
221
222# Invoke a second make in the output directory, passing relevant variables
223__sub-make:
224	$(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
225	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
226
227else # need-sub-make
228
229# We process the rest of the Makefile if this is the final invocation of make
230
231ifeq ($(abs_srctree),$(abs_objtree))
232        # building in the source tree
233        srctree := .
234	building_out_of_srctree :=
235else
236        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
237                # building in a subdirectory of the source tree
238                srctree := ..
239        else
240                srctree := $(abs_srctree)
241        endif
242	building_out_of_srctree := 1
243endif
244
245ifneq ($(KBUILD_ABS_SRCTREE),)
246srctree := $(abs_srctree)
247endif
248
249objtree		:= .
250
251VPATH		:=
252
253ifeq ($(KBUILD_EXTMOD),)
254ifdef building_out_of_srctree
255VPATH		:= $(srctree)
256endif
257endif
258
259export building_out_of_srctree srctree objtree VPATH
260
261# To make sure we do not include .config for any of the *config targets
262# catch them early, and hand them over to scripts/kconfig/Makefile
263# It is allowed to specify more targets when calling make, including
264# mixing *config targets and build targets.
265# For example 'make oldconfig all'.
266# Detect when mixed targets is specified, and make a second invocation
267# of make so .config is not included in this case either (for *config).
268
269version_h := include/generated/uapi/linux/version.h
270
271clean-targets := %clean mrproper cleandocs
272no-dot-config-targets := $(clean-targets) \
273			 cscope gtags TAGS tags help% %docs check% coccicheck \
274			 $(version_h) headers headers_% archheaders archscripts \
275			 %asm-generic kernelversion %src-pkg dt_binding_check \
276			 outputmakefile rustavailable rustfmt rustfmtcheck
277no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
278			  image_name
279single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
280
281config-build	:=
282mixed-build	:=
283need-config	:= 1
284may-sync-config	:= 1
285single-build	:=
286
287ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
288    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
289        need-config :=
290    endif
291endif
292
293ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
294    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
295        may-sync-config :=
296    endif
297endif
298
299need-compiler := $(may-sync-config)
300
301ifneq ($(KBUILD_EXTMOD),)
302    may-sync-config :=
303endif
304
305ifeq ($(KBUILD_EXTMOD),)
306    ifneq ($(filter %config,$(MAKECMDGOALS)),)
307        config-build := 1
308        ifneq ($(words $(MAKECMDGOALS)),1)
309            mixed-build := 1
310        endif
311    endif
312endif
313
314# We cannot build single targets and the others at the same time
315ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
316    single-build := 1
317    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
318        mixed-build := 1
319    endif
320endif
321
322# For "make -j clean all", "make -j mrproper defconfig all", etc.
323ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
324    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
325        mixed-build := 1
326    endif
327endif
328
329# install and modules_install need also be processed one by one
330ifneq ($(filter install,$(MAKECMDGOALS)),)
331    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
332        mixed-build := 1
333    endif
334endif
335
336ifdef mixed-build
337# ===========================================================================
338# We're called with mixed targets (*config and build targets).
339# Handle them one by one.
340
341PHONY += $(MAKECMDGOALS) __build_one_by_one
342
343$(MAKECMDGOALS): __build_one_by_one
344	@:
345
346__build_one_by_one:
347	$(Q)set -e; \
348	for i in $(MAKECMDGOALS); do \
349		$(MAKE) -f $(srctree)/Makefile $$i; \
350	done
351
352else # !mixed-build
353
354include $(srctree)/scripts/Kbuild.include
355
356# Read KERNELRELEASE from include/config/kernel.release (if it exists)
357KERNELRELEASE = $(call read-file, include/config/kernel.release)
358KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
359export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
360
361include $(srctree)/scripts/subarch.include
362
363# Cross compiling and selecting different set of gcc/bin-utils
364# ---------------------------------------------------------------------------
365#
366# When performing cross compilation for other architectures ARCH shall be set
367# to the target architecture. (See arch/* for the possibilities).
368# ARCH can be set during invocation of make:
369# make ARCH=arm64
370# Another way is to have ARCH set in the environment.
371# The default ARCH is the host where make is executed.
372
373# CROSS_COMPILE specify the prefix used for all executables used
374# during compilation. Only gcc and related bin-utils executables
375# are prefixed with $(CROSS_COMPILE).
376# CROSS_COMPILE can be set on the command line
377# make CROSS_COMPILE=aarch64-linux-gnu-
378# Alternatively CROSS_COMPILE can be set in the environment.
379# Default value for CROSS_COMPILE is not to prefix executables
380# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
381ARCH		?= $(SUBARCH)
382
383# Architecture as present in compile.h
384UTS_MACHINE 	:= $(ARCH)
385SRCARCH 	:= $(ARCH)
386
387# Additional ARCH settings for x86
388ifeq ($(ARCH),i386)
389        SRCARCH := x86
390endif
391ifeq ($(ARCH),x86_64)
392        SRCARCH := x86
393endif
394
395# Additional ARCH settings for sparc
396ifeq ($(ARCH),sparc32)
397       SRCARCH := sparc
398endif
399ifeq ($(ARCH),sparc64)
400       SRCARCH := sparc
401endif
402
403# Additional ARCH settings for parisc
404ifeq ($(ARCH),parisc64)
405       SRCARCH := parisc
406endif
407
408export cross_compiling :=
409ifneq ($(SRCARCH),$(SUBARCH))
410cross_compiling := 1
411endif
412
413KCONFIG_CONFIG	?= .config
414export KCONFIG_CONFIG
415
416# SHELL used by kbuild
417CONFIG_SHELL := sh
418
419HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
420HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
421HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
422
423ifneq ($(LLVM),)
424ifneq ($(filter %/,$(LLVM)),)
425LLVM_PREFIX := $(LLVM)
426else ifneq ($(filter -%,$(LLVM)),)
427LLVM_SUFFIX := $(LLVM)
428endif
429
430HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
431HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
432else
433HOSTCC	= gcc
434HOSTCXX	= g++
435endif
436HOSTRUSTC = rustc
437HOSTPKG_CONFIG	= pkg-config
438
439KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
440			 -O2 -fomit-frame-pointer -std=gnu11
441KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
442KBUILD_USERLDFLAGS := $(USERLDFLAGS)
443
444# These flags apply to all Rust code in the tree, including the kernel and
445# host programs.
446export rust_common_flags := --edition=2021 \
447			    -Zbinary_dep_depinfo=y \
448			    -Astable_features \
449			    -Dnon_ascii_idents \
450			    -Dunsafe_op_in_unsafe_fn \
451			    -Wmissing_docs \
452			    -Wrust_2018_idioms \
453			    -Wunreachable_pub \
454			    -Wclippy::all \
455			    -Wclippy::dbg_macro \
456			    -Wclippy::ignored_unit_patterns \
457			    -Wclippy::mut_mut \
458			    -Wclippy::needless_bitwise_bool \
459			    -Wclippy::needless_continue \
460			    -Wclippy::no_mangle_with_rust_abi \
461			    -Wclippy::undocumented_unsafe_blocks \
462			    -Wclippy::unnecessary_safety_comment \
463			    -Wclippy::unnecessary_safety_doc \
464			    -Wrustdoc::missing_crate_level_docs \
465			    -Wrustdoc::unescaped_backticks
466
467KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
468		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
469KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
470		       -I $(srctree)/scripts/include
471KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
472			-Zallow-features= $(HOSTRUSTFLAGS)
473KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
474KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
475
476# Make variables (CC, etc...)
477CPP		= $(CC) -E
478ifneq ($(LLVM),)
479CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
480LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
481AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
482NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
483OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
484OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
485READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
486STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
487else
488CC		= $(CROSS_COMPILE)gcc
489LD		= $(CROSS_COMPILE)ld
490AR		= $(CROSS_COMPILE)ar
491NM		= $(CROSS_COMPILE)nm
492OBJCOPY		= $(CROSS_COMPILE)objcopy
493OBJDUMP		= $(CROSS_COMPILE)objdump
494READELF		= $(CROSS_COMPILE)readelf
495STRIP		= $(CROSS_COMPILE)strip
496endif
497RUSTC		= rustc
498RUSTDOC		= rustdoc
499RUSTFMT		= rustfmt
500CLIPPY_DRIVER	= clippy-driver
501BINDGEN		= bindgen
502PAHOLE		= pahole
503RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
504LEX		= flex
505YACC		= bison
506AWK		= awk
507INSTALLKERNEL  := installkernel
508PERL		= perl
509PYTHON3		= python3
510CHECK		= sparse
511BASH		= bash
512KGZIP		= gzip
513KBZIP2		= bzip2
514KLZOP		= lzop
515LZMA		= lzma
516LZ4		= lz4c
517XZ		= xz
518ZSTD		= zstd
519
520CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
521		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
522NOSTDINC_FLAGS :=
523CFLAGS_MODULE   =
524RUSTFLAGS_MODULE =
525AFLAGS_MODULE   =
526LDFLAGS_MODULE  =
527CFLAGS_KERNEL	=
528RUSTFLAGS_KERNEL =
529AFLAGS_KERNEL	=
530LDFLAGS_vmlinux =
531
532# Use USERINCLUDE when you must reference the UAPI directories only.
533USERINCLUDE    := \
534		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
535		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
536		-I$(srctree)/include/uapi \
537		-I$(objtree)/include/generated/uapi \
538                -include $(srctree)/include/linux/compiler-version.h \
539                -include $(srctree)/include/linux/kconfig.h
540
541# Use LINUXINCLUDE when you must reference the include/ directory.
542# Needed to be compatible with the O= option
543LINUXINCLUDE    := \
544		-I$(srctree)/arch/$(SRCARCH)/include \
545		-I$(objtree)/arch/$(SRCARCH)/include/generated \
546		$(if $(building_out_of_srctree),-I$(srctree)/include) \
547		-I$(objtree)/include \
548		$(USERINCLUDE)
549
550KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
551
552KBUILD_CFLAGS :=
553KBUILD_CFLAGS += -std=gnu11
554KBUILD_CFLAGS += -fshort-wchar
555KBUILD_CFLAGS += -funsigned-char
556KBUILD_CFLAGS += -fno-common
557KBUILD_CFLAGS += -fno-PIE
558KBUILD_CFLAGS += -fno-strict-aliasing
559
560KBUILD_CPPFLAGS := -D__KERNEL__
561KBUILD_RUSTFLAGS := $(rust_common_flags) \
562		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
563		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
564		    -Csymbol-mangling-version=v0 \
565		    -Crelocation-model=static \
566		    -Zfunction-sections=n \
567		    -Wclippy::float_arithmetic
568
569KBUILD_AFLAGS_KERNEL :=
570KBUILD_CFLAGS_KERNEL :=
571KBUILD_RUSTFLAGS_KERNEL :=
572KBUILD_AFLAGS_MODULE  := -DMODULE
573KBUILD_CFLAGS_MODULE  := -DMODULE
574KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
575KBUILD_LDFLAGS_MODULE :=
576KBUILD_LDFLAGS :=
577CLANG_FLAGS :=
578
579ifeq ($(KBUILD_CLIPPY),1)
580	RUSTC_OR_CLIPPY_QUIET := CLIPPY
581	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
582else
583	RUSTC_OR_CLIPPY_QUIET := RUSTC
584	RUSTC_OR_CLIPPY = $(RUSTC)
585endif
586
587# Allows the usage of unstable features in stable compilers.
588export RUSTC_BOOTSTRAP := 1
589
590export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
591export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN
592export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
593export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
594export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
595export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
596export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
597export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
598
599export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
600export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
601export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
602export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
603export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
604export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
605
606# Files to ignore in find ... statements
607
608export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
609			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
610			  -prune -o
611
612# ===========================================================================
613# Rules shared between *config targets and build targets
614
615# Basic helpers built in scripts/basic/
616PHONY += scripts_basic
617scripts_basic:
618	$(Q)$(MAKE) $(build)=scripts/basic
619
620PHONY += outputmakefile
621ifdef building_out_of_srctree
622# Before starting out-of-tree build, make sure the source tree is clean.
623# outputmakefile generates a Makefile in the output directory, if using a
624# separate output directory. This allows convenient use of make in the
625# output directory.
626# At the same time when output Makefile generated, generate .gitignore to
627# ignore whole output directory
628
629quiet_cmd_makefile = GEN     Makefile
630      cmd_makefile = { \
631	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
632	echo "include $(srctree)/Makefile"; \
633	} > Makefile
634
635outputmakefile:
636	@if [ -f $(srctree)/.config -o \
637		 -d $(srctree)/include/config -o \
638		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
639		echo >&2 "***"; \
640		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
641		echo >&2 "*** in $(abs_srctree)";\
642		echo >&2 "***"; \
643		false; \
644	fi
645	$(Q)ln -fsn $(srctree) source
646	$(call cmd,makefile)
647	$(Q)test -e .gitignore || \
648	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
649endif
650
651# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
652# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
653# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they
654# need export), and from include/config/auto.conf.cmd to detect the compiler
655# upgrade.
656CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
657RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
658
659ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
660include $(srctree)/scripts/Makefile.clang
661endif
662
663# Include this also for config targets because some architectures need
664# cc-cross-prefix to determine CROSS_COMPILE.
665ifdef need-compiler
666include $(srctree)/scripts/Makefile.compiler
667endif
668
669ifdef config-build
670# ===========================================================================
671# *config targets only - make sure prerequisites are updated, and descend
672# in scripts/kconfig to make the *config target
673
674# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
675# KBUILD_DEFCONFIG may point out an alternative default configuration
676# used for 'make defconfig'
677include $(srctree)/arch/$(SRCARCH)/Makefile
678export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
679
680config: outputmakefile scripts_basic FORCE
681	$(Q)$(MAKE) $(build)=scripts/kconfig $@
682
683%config: outputmakefile scripts_basic FORCE
684	$(Q)$(MAKE) $(build)=scripts/kconfig $@
685
686else #!config-build
687# ===========================================================================
688# Build targets only - this includes vmlinux, arch-specific targets, clean
689# targets and others. In general all targets except *config targets.
690
691# If building an external module we do not care about the all: rule
692# but instead __all depend on modules
693PHONY += all
694ifeq ($(KBUILD_EXTMOD),)
695__all: all
696else
697__all: modules
698endif
699
700targets :=
701
702# Decide whether to build built-in, modular, or both.
703# Normally, just do built-in.
704
705KBUILD_MODULES :=
706KBUILD_BUILTIN := 1
707
708# If we have only "make modules", don't compile built-in objects.
709ifeq ($(MAKECMDGOALS),modules)
710  KBUILD_BUILTIN :=
711endif
712
713# If we have "make <whatever> modules", compile modules
714# in addition to whatever we do anyway.
715# Just "make" or "make all" shall build modules as well
716
717ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
718  KBUILD_MODULES := 1
719endif
720
721ifeq ($(MAKECMDGOALS),)
722  KBUILD_MODULES := 1
723endif
724
725export KBUILD_MODULES KBUILD_BUILTIN
726
727ifdef need-config
728include include/config/auto.conf
729endif
730
731ifeq ($(KBUILD_EXTMOD),)
732# Objects we will link into vmlinux / subdirs we need to visit
733core-y		:=
734drivers-y	:=
735libs-y		:= lib/
736endif # KBUILD_EXTMOD
737
738# The all: target is the default when no target is given on the
739# command line.
740# This allow a user to issue only 'make' to build a kernel including modules
741# Defaults to vmlinux, but the arch makefile usually adds further targets
742all: vmlinux
743
744CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
745ifdef CONFIG_CC_IS_GCC
746CFLAGS_GCOV	+= -fno-tree-loop-im
747endif
748export CFLAGS_GCOV
749
750# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
751ifdef CONFIG_FUNCTION_TRACER
752  CC_FLAGS_FTRACE := -pg
753endif
754
755include $(srctree)/arch/$(SRCARCH)/Makefile
756
757ifdef need-config
758ifdef may-sync-config
759# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
760# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
761# because some architectures define CROSS_COMPILE there.
762include include/config/auto.conf.cmd
763
764$(KCONFIG_CONFIG):
765	@echo >&2 '***'
766	@echo >&2 '*** Configuration file "$@" not found!'
767	@echo >&2 '***'
768	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
769	@echo >&2 '*** "make menuconfig" or "make xconfig").'
770	@echo >&2 '***'
771	@/bin/false
772
773# The actual configuration files used during the build are stored in
774# include/generated/ and include/config/. Update them if .config is newer than
775# include/config/auto.conf (which mirrors .config).
776#
777# This exploits the 'multi-target pattern rule' trick.
778# The syncconfig should be executed only once to make all the targets.
779# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
780#
781# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
782# so you cannot notice that Kconfig is waiting for the user input.
783%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
784	$(Q)$(kecho) "  SYNC    $@"
785	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
786else # !may-sync-config
787# External modules and some install targets need include/generated/autoconf.h
788# and include/config/auto.conf but do not care if they are up-to-date.
789# Use auto.conf to trigger the test
790PHONY += include/config/auto.conf
791
792include/config/auto.conf:
793	@test -e include/generated/autoconf.h -a -e $@ || (		\
794	echo >&2;							\
795	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
796	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
797	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
798	echo >&2 ;							\
799	/bin/false)
800
801endif # may-sync-config
802endif # need-config
803
804KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
805
806ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
807KBUILD_CFLAGS += -O2
808KBUILD_RUSTFLAGS += -Copt-level=2
809else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
810KBUILD_CFLAGS += -Os
811KBUILD_RUSTFLAGS += -Copt-level=s
812endif
813
814# Always set `debug-assertions` and `overflow-checks` because their default
815# depends on `opt-level` and `debug-assertions`, respectively.
816KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
817KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
818
819# Tell gcc to never replace conditional load with a non-conditional one
820ifdef CONFIG_CC_IS_GCC
821# gcc-10 renamed --param=allow-store-data-races=0 to
822# -fno-allow-store-data-races.
823KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
824KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
825endif
826
827ifdef CONFIG_READABLE_ASM
828# Disable optimizations that make assembler listings hard to read.
829# reorder blocks reorders the control in the function
830# ipa clone creates specialized cloned functions
831# partial inlining inlines only parts of functions
832KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
833endif
834
835stackp-flags-y                                    := -fno-stack-protector
836stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
837stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
838
839KBUILD_CFLAGS += $(stackp-flags-y)
840
841KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
842KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
843
844ifdef CONFIG_FRAME_POINTER
845KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
846KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
847else
848# Some targets (ARM with Thumb2, for example), can't be built with frame
849# pointers.  For those, we don't have FUNCTION_TRACER automatically
850# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
851# incompatible with -fomit-frame-pointer with current GCC, so we don't use
852# -fomit-frame-pointer with FUNCTION_TRACER.
853# In the Rust target specification, "frame-pointer" is set explicitly
854# to "may-omit".
855ifndef CONFIG_FUNCTION_TRACER
856KBUILD_CFLAGS	+= -fomit-frame-pointer
857endif
858endif
859
860# Initialize all stack variables with a 0xAA pattern.
861ifdef CONFIG_INIT_STACK_ALL_PATTERN
862KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
863endif
864
865# Initialize all stack variables with a zero value.
866ifdef CONFIG_INIT_STACK_ALL_ZERO
867KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
868ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
869# https://github.com/llvm/llvm-project/issues/44842
870CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
871export CC_AUTO_VAR_INIT_ZERO_ENABLER
872KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
873endif
874endif
875
876# While VLAs have been removed, GCC produces unreachable stack probes
877# for the randomize_kstack_offset feature. Disable it for all compilers.
878KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
879
880# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
881ifdef CONFIG_ZERO_CALL_USED_REGS
882KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
883endif
884
885ifdef CONFIG_FUNCTION_TRACER
886ifdef CONFIG_FTRACE_MCOUNT_USE_CC
887  CC_FLAGS_FTRACE	+= -mrecord-mcount
888  ifdef CONFIG_HAVE_NOP_MCOUNT
889    ifeq ($(call cc-option-yn, -mnop-mcount),y)
890      CC_FLAGS_FTRACE	+= -mnop-mcount
891      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
892    endif
893  endif
894endif
895ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
896  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
897    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
898  endif
899endif
900ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
901  ifdef CONFIG_HAVE_C_RECORDMCOUNT
902    BUILD_C_RECORDMCOUNT := y
903    export BUILD_C_RECORDMCOUNT
904  endif
905endif
906ifdef CONFIG_HAVE_FENTRY
907  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
908  ifeq ($(call cc-option-yn, -mfentry),y)
909    CC_FLAGS_FTRACE	+= -mfentry
910    CC_FLAGS_USING	+= -DCC_USING_FENTRY
911  endif
912endif
913export CC_FLAGS_FTRACE
914KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
915KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
916endif
917
918# We trigger additional mismatches with less inlining
919ifdef CONFIG_DEBUG_SECTION_MISMATCH
920KBUILD_CFLAGS += -fno-inline-functions-called-once
921endif
922
923# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
924ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
925KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
926KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
927LDFLAGS_vmlinux += --gc-sections
928endif
929
930ifdef CONFIG_SHADOW_CALL_STACK
931ifndef CONFIG_DYNAMIC_SCS
932CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
933KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
934KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack
935endif
936export CC_FLAGS_SCS
937endif
938
939ifdef CONFIG_LTO_CLANG
940ifdef CONFIG_LTO_CLANG_THIN
941CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
942else
943CC_FLAGS_LTO	:= -flto
944endif
945CC_FLAGS_LTO	+= -fvisibility=hidden
946
947# Limit inlining across translation units to reduce binary size
948KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
949endif
950
951ifdef CONFIG_LTO
952KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
953KBUILD_AFLAGS	+= -fno-lto
954export CC_FLAGS_LTO
955endif
956
957ifdef CONFIG_CFI_CLANG
958CC_FLAGS_CFI	:= -fsanitize=kcfi
959ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
960	CC_FLAGS_CFI	+= -fsanitize-cfi-icall-experimental-normalize-integers
961endif
962ifdef CONFIG_RUST
963	# Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects
964	# CONFIG_CFI_ICALL_NORMALIZE_INTEGERS.
965	RUSTC_FLAGS_CFI   := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers
966	KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI)
967	export RUSTC_FLAGS_CFI
968endif
969KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
970export CC_FLAGS_CFI
971endif
972
973# Architectures can define flags to add/remove for floating-point support
974CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
975export CC_FLAGS_FPU
976export CC_FLAGS_NO_FPU
977
978ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
979# Set the minimal function alignment. Use the newer GCC option
980# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
981# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
982ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
983KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
984else
985KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
986endif
987endif
988
989# arch Makefile may override CC so keep this after arch Makefile is included
990NOSTDINC_FLAGS += -nostdinc
991
992# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
993# the kernel uses only C99 flexible arrays for dynamically sized trailing
994# arrays. Enforce this for everything that may examine structure sizes and
995# perform bounds checking.
996KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
997
998#Currently, disable -Wstringop-overflow for GCC 11, globally.
999KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
1000KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
1001
1002# disable invalid "can't wrap" optimizations for signed / pointers
1003KBUILD_CFLAGS	+= -fno-strict-overflow
1004
1005# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1006KBUILD_CFLAGS  += -fno-stack-check
1007
1008# conserve stack if available
1009ifdef CONFIG_CC_IS_GCC
1010KBUILD_CFLAGS   += -fconserve-stack
1011endif
1012
1013# change __FILE__ to the relative path from the srctree
1014KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1015
1016# include additional Makefiles when needed
1017include-y			:= scripts/Makefile.extrawarn
1018include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1019include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1020include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1021include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1022include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1023include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1024include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1025include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1026include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1027
1028include $(addprefix $(srctree)/, $(include-y))
1029
1030# scripts/Makefile.gcc-plugins is intentionally included last.
1031# Do not add $(call cc-option,...) below this line. When you build the kernel
1032# from the clean source tree, the GCC plugins do not exist at this point.
1033
1034# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1035KBUILD_CPPFLAGS += $(KCPPFLAGS)
1036KBUILD_AFLAGS   += $(KAFLAGS)
1037KBUILD_CFLAGS   += $(KCFLAGS)
1038KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1039
1040KBUILD_LDFLAGS_MODULE += --build-id=sha1
1041LDFLAGS_vmlinux += --build-id=sha1
1042
1043KBUILD_LDFLAGS	+= -z noexecstack
1044ifeq ($(CONFIG_LD_IS_BFD),y)
1045KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1046endif
1047
1048ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1049LDFLAGS_vmlinux	+= -X
1050endif
1051
1052ifeq ($(CONFIG_RELR),y)
1053# ld.lld before 15 did not support -z pack-relative-relocs.
1054LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1055endif
1056
1057# We never want expected sections to be placed heuristically by the
1058# linker. All sections should be explicitly named in the linker script.
1059ifdef CONFIG_LD_ORPHAN_WARN
1060LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1061endif
1062
1063# Align the bit size of userspace programs with the kernel
1064KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1065KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1066
1067# make the checker run with the right architecture
1068CHECKFLAGS += --arch=$(ARCH)
1069
1070# insure the checker run with the right endianness
1071CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1072
1073# the checker needs the correct machine size
1074CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1075
1076# Default kernel image to build when no specific target is given.
1077# KBUILD_IMAGE may be overruled on the command line or
1078# set in the environment
1079# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1080# this default value
1081export KBUILD_IMAGE ?= vmlinux
1082
1083#
1084# INSTALL_PATH specifies where to place the updated kernel and system map
1085# images. Default is /boot, but you can set it to other values
1086export	INSTALL_PATH ?= /boot
1087
1088#
1089# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1090# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1091# an argument if needed. Otherwise it defaults to the kernel install path
1092#
1093export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1094
1095#
1096# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1097# relocations required by build roots.  This is not defined in the
1098# makefile but the argument can be passed to make if needed.
1099#
1100
1101MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1102export MODLIB
1103
1104PHONY += prepare0
1105
1106export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1107export MODORDER := $(extmod_prefix)modules.order
1108export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1109
1110ifeq ($(KBUILD_EXTMOD),)
1111
1112build-dir	:= .
1113clean-dirs	:= $(sort . Documentation \
1114		     $(patsubst %/,%,$(filter %/, $(core-) \
1115			$(drivers-) $(libs-))))
1116
1117export ARCH_CORE	:= $(core-y)
1118export ARCH_LIB		:= $(filter %/, $(libs-y))
1119export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1120# Externally visible symbols (used by link-vmlinux.sh)
1121
1122KBUILD_VMLINUX_OBJS := ./built-in.a
1123ifdef CONFIG_MODULES
1124KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1125KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1126else
1127KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1128endif
1129
1130export KBUILD_VMLINUX_LIBS
1131export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1132
1133ifdef CONFIG_TRIM_UNUSED_KSYMS
1134# For the kernel to actually contain only the needed exported symbols,
1135# we have to build modules as well to determine what those symbols are.
1136KBUILD_MODULES := 1
1137endif
1138
1139# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1140quiet_cmd_ar_vmlinux.a = AR      $@
1141      cmd_ar_vmlinux.a = \
1142	rm -f $@; \
1143	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1144	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1145
1146targets += vmlinux.a
1147vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1148	$(call if_changed,ar_vmlinux.a)
1149
1150PHONY += vmlinux_o
1151vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1152	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1153
1154vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1155	@:
1156
1157PHONY += vmlinux
1158# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1159# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1160# unrelated; the decompressors just happen to have the same base name,
1161# arch/*/boot/compressed/vmlinux.
1162# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1163#
1164# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1165#   https://savannah.gnu.org/bugs/?61463
1166# For Make > 4.4, the following simple code will work:
1167#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1168vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1169vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1170vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1171	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1172
1173# The actual objects are generated when descending,
1174# make sure no implicit rule kicks in
1175$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1176
1177ifeq ($(origin KERNELRELEASE),file)
1178filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1179else
1180filechk_kernel.release = echo $(KERNELRELEASE)
1181endif
1182
1183# Store (new) KERNELRELEASE string in include/config/kernel.release
1184include/config/kernel.release: FORCE
1185	$(call filechk,kernel.release)
1186
1187# Additional helpers built in scripts/
1188# Carefully list dependencies so we do not try to build scripts twice
1189# in parallel
1190PHONY += scripts
1191scripts: scripts_basic scripts_dtc
1192	$(Q)$(MAKE) $(build)=$(@)
1193
1194# Things we need to do before we recursively start building the kernel
1195# or the modules are listed in "prepare".
1196# A multi level approach is used. prepareN is processed before prepareN-1.
1197# archprepare is used in arch Makefiles and when processed asm symlink,
1198# version.h and scripts_basic is processed / created.
1199
1200PHONY += prepare archprepare
1201
1202archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1203	asm-generic $(version_h) include/generated/utsrelease.h \
1204	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1205
1206prepare0: archprepare
1207	$(Q)$(MAKE) $(build)=scripts/mod
1208	$(Q)$(MAKE) $(build)=. prepare
1209
1210# All the preparing..
1211prepare: prepare0
1212ifdef CONFIG_RUST
1213	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1214	$(Q)$(MAKE) $(build)=rust
1215endif
1216
1217PHONY += remove-stale-files
1218remove-stale-files:
1219	$(Q)$(srctree)/scripts/remove-stale-files
1220
1221# Support for using generic headers in asm-generic
1222asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1223
1224PHONY += asm-generic uapi-asm-generic
1225asm-generic: uapi-asm-generic
1226	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1227	generic=include/asm-generic
1228uapi-asm-generic:
1229	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1230	generic=include/uapi/asm-generic
1231
1232# Generate some files
1233# ---------------------------------------------------------------------------
1234
1235# KERNELRELEASE can change from a few different places, meaning version.h
1236# needs to be updated, so this check is forced on all builds
1237
1238uts_len := 64
1239define filechk_utsrelease.h
1240	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1241	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1242	  exit 1;                                                         \
1243	fi;                                                               \
1244	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1245endef
1246
1247define filechk_version.h
1248	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1249		echo \#define LINUX_VERSION_CODE $(shell                 \
1250		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1251	else                                                             \
1252		echo \#define LINUX_VERSION_CODE $(shell                 \
1253		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1254	fi;                                                              \
1255	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1256	((c) > 255 ? 255 : (c)))';                                       \
1257	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1258	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1259	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1260endef
1261
1262$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1263$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1264$(version_h): FORCE
1265	$(call filechk,version.h)
1266
1267include/generated/utsrelease.h: include/config/kernel.release FORCE
1268	$(call filechk,utsrelease.h)
1269
1270filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1271	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1272
1273include/generated/compile.h: FORCE
1274	$(call filechk,compile.h)
1275
1276PHONY += headerdep
1277headerdep:
1278	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1279	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1280
1281# ---------------------------------------------------------------------------
1282# Kernel headers
1283
1284#Default location for installed headers
1285export INSTALL_HDR_PATH = $(objtree)/usr
1286
1287quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1288      cmd_headers_install = \
1289	mkdir -p $(INSTALL_HDR_PATH); \
1290	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1291	usr/include $(INSTALL_HDR_PATH)
1292
1293PHONY += headers_install
1294headers_install: headers
1295	$(call cmd,headers_install)
1296
1297PHONY += archheaders archscripts
1298
1299hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1300
1301PHONY += headers
1302headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1303	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1304	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1305	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1306
1307ifdef CONFIG_HEADERS_INSTALL
1308prepare: headers
1309endif
1310
1311PHONY += scripts_unifdef
1312scripts_unifdef: scripts_basic
1313	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1314
1315# ---------------------------------------------------------------------------
1316# Install
1317
1318# Many distributions have the custom install script, /sbin/installkernel.
1319# If DKMS is installed, 'make install' will eventually recurse back
1320# to this Makefile to build and install external modules.
1321# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1322
1323quiet_cmd_install = INSTALL $(INSTALL_PATH)
1324      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1325
1326# ---------------------------------------------------------------------------
1327# vDSO install
1328
1329PHONY += vdso_install
1330vdso_install: export INSTALL_FILES = $(vdso-install-y)
1331vdso_install:
1332	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1333
1334# ---------------------------------------------------------------------------
1335# Tools
1336
1337ifdef CONFIG_OBJTOOL
1338prepare: tools/objtool
1339endif
1340
1341ifdef CONFIG_BPF
1342ifdef CONFIG_DEBUG_INFO_BTF
1343prepare: tools/bpf/resolve_btfids
1344endif
1345endif
1346
1347# The tools build system is not a part of Kbuild and tends to introduce
1348# its own unique issues. If you need to integrate a new tool into Kbuild,
1349# please consider locating that tool outside the tools/ tree and using the
1350# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1351# here. See Documentation/kbuild/makefiles.rst for details.
1352
1353PHONY += resolve_btfids_clean
1354
1355resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1356
1357# tools/bpf/resolve_btfids directory might not exist
1358# in output directory, skip its clean in that case
1359resolve_btfids_clean:
1360ifneq ($(wildcard $(resolve_btfids_O)),)
1361	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1362endif
1363
1364# Clear a bunch of variables before executing the submake
1365ifeq ($(quiet),silent_)
1366tools_silent=s
1367endif
1368
1369tools/: FORCE
1370	$(Q)mkdir -p $(objtree)/tools
1371	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1372
1373tools/%: FORCE
1374	$(Q)mkdir -p $(objtree)/tools
1375	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1376
1377# ---------------------------------------------------------------------------
1378# Kernel selftest
1379
1380PHONY += kselftest
1381kselftest: headers
1382	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1383
1384kselftest-%: headers FORCE
1385	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1386
1387PHONY += kselftest-merge
1388kselftest-merge:
1389	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1390	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1391		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1392	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1393
1394# ---------------------------------------------------------------------------
1395# Devicetree files
1396
1397ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1398dtstree := arch/$(SRCARCH)/boot/dts
1399endif
1400
1401ifneq ($(dtstree),)
1402
1403%.dtb: dtbs_prepare
1404	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1405
1406%.dtbo: dtbs_prepare
1407	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1408
1409PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1410dtbs: dtbs_prepare
1411	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1412
1413# include/config/kernel.release is actually needed when installing DTBs because
1414# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1415# dtbs_install depend on it as dtbs_install may run as root.
1416dtbs_prepare: include/config/kernel.release scripts_dtc
1417
1418ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1419export CHECK_DTBS=y
1420endif
1421
1422ifneq ($(CHECK_DTBS),)
1423dtbs_prepare: dt_binding_schemas
1424endif
1425
1426dtbs_check: dtbs
1427
1428dtbs_install:
1429	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1430
1431ifdef CONFIG_OF_EARLY_FLATTREE
1432all: dtbs
1433endif
1434
1435endif
1436
1437PHONY += scripts_dtc
1438scripts_dtc: scripts_basic
1439	$(Q)$(MAKE) $(build)=scripts/dtc
1440
1441ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1442export CHECK_DTBS=y
1443endif
1444
1445PHONY += dt_binding_check dt_binding_schemas
1446dt_binding_check: dt_binding_schemas scripts_dtc
1447	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1448
1449dt_binding_schemas:
1450	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1451
1452PHONY += dt_compatible_check
1453dt_compatible_check: dt_binding_schemas
1454	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1455
1456# ---------------------------------------------------------------------------
1457# Modules
1458
1459ifdef CONFIG_MODULES
1460
1461# By default, build modules as well
1462
1463all: modules
1464
1465# When we're building modules with modversions, we need to consider
1466# the built-in objects during the descend as well, in order to
1467# make sure the checksums are up to date before we record them.
1468ifdef CONFIG_MODVERSIONS
1469  KBUILD_BUILTIN := 1
1470endif
1471
1472# Build modules
1473#
1474
1475# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1476# is an exception.
1477ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1478KBUILD_BUILTIN := 1
1479modules: vmlinux
1480endif
1481
1482modules: modules_prepare
1483
1484# Target to prepare building external modules
1485modules_prepare: prepare
1486	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1487
1488endif # CONFIG_MODULES
1489
1490###
1491# Cleaning is done on three levels.
1492# make clean     Delete most generated files
1493#                Leave enough to build external modules
1494# make mrproper  Delete the current configuration, and all generated files
1495# make distclean Remove editor backup files, patch leftover files and the like
1496
1497# Directories & files removed with 'make clean'
1498CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1499	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1500	       modules.builtin.ranges vmlinux.o.map \
1501	       compile_commands.json rust/test \
1502	       rust-project.json .vmlinux.objs .vmlinux.export.c
1503
1504# Directories & files removed with 'make mrproper'
1505MRPROPER_FILES += include/config include/generated          \
1506		  arch/$(SRCARCH)/include/generated .objdiff \
1507		  debian snap tar-install PKGBUILD pacman \
1508		  .config .config.old .version \
1509		  Module.symvers \
1510		  certs/signing_key.pem \
1511		  certs/x509.genkey \
1512		  vmlinux-gdb.py \
1513		  rpmbuild \
1514		  rust/libmacros.so
1515
1516# clean - Delete most, but leave enough to build external modules
1517#
1518clean: private rm-files := $(CLEAN_FILES)
1519
1520PHONY += archclean vmlinuxclean
1521
1522vmlinuxclean:
1523	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1524	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1525
1526clean: archclean vmlinuxclean resolve_btfids_clean
1527
1528# mrproper - Delete all generated files, including .config
1529#
1530mrproper: private rm-files := $(MRPROPER_FILES)
1531mrproper-dirs      := $(addprefix _mrproper_,scripts)
1532
1533PHONY += $(mrproper-dirs) mrproper
1534$(mrproper-dirs):
1535	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1536
1537mrproper: clean $(mrproper-dirs)
1538	$(call cmd,rmfiles)
1539	@find . $(RCS_FIND_IGNORE) \
1540		\( -name '*.rmeta' \) \
1541		-type f -print | xargs rm -f
1542
1543# distclean
1544#
1545PHONY += distclean
1546
1547distclean: mrproper
1548	@find . $(RCS_FIND_IGNORE) \
1549		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1550		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1551		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1552		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1553		-type f -print | xargs rm -f
1554
1555
1556# Packaging of the kernel to various formats
1557# ---------------------------------------------------------------------------
1558
1559%src-pkg: FORCE
1560	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1561%pkg: include/config/kernel.release FORCE
1562	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1563
1564# Brief documentation of the typical targets used
1565# ---------------------------------------------------------------------------
1566
1567boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1568boards := $(sort $(notdir $(boards)))
1569board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1570board-dirs := $(sort $(notdir $(board-dirs:/=)))
1571
1572PHONY += help
1573help:
1574	@echo  'Cleaning targets:'
1575	@echo  '  clean		  - Remove most generated files but keep the config and'
1576	@echo  '                    enough build support to build external modules'
1577	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1578	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1579	@echo  ''
1580	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1581	@echo  ''
1582	@echo  'Other generic targets:'
1583	@echo  '  all		  - Build all targets marked with [*]'
1584	@echo  '* vmlinux	  - Build the bare kernel'
1585	@echo  '* modules	  - Build all modules'
1586	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1587	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1588	@echo  '  dir/            - Build all files in dir and below'
1589	@echo  '  dir/file.[ois]  - Build specified target only'
1590	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1591	@echo  '                    (requires compiler support for LLVM assembly generation)'
1592	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1593	@echo  '                    (requires a recent binutils and recent build (System.map))'
1594	@echo  '  dir/file.ko     - Build module including final link'
1595	@echo  '  modules_prepare - Set up for building external modules'
1596	@echo  '  tags/TAGS	  - Generate tags file for editors'
1597	@echo  '  cscope	  - Generate cscope index'
1598	@echo  '  gtags           - Generate GNU GLOBAL index'
1599	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1600	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1601	@echo  '  image_name	  - Output the image name (use with make -s)'
1602	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1603	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1604	 echo  ''
1605	@echo  'Static analysers:'
1606	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1607	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1608	@echo  '  versioncheck    - Sanity check on version.h usage'
1609	@echo  '  includecheck    - Check for duplicate included header files'
1610	@echo  '  export_report   - List the usages of all exported symbols'
1611	@echo  '  headerdep       - Detect inclusion cycles in headers'
1612	@echo  '  coccicheck      - Check with Coccinelle'
1613	@echo  '  clang-analyzer  - Check with clang static analyzer'
1614	@echo  '  clang-tidy      - Check with clang-tidy'
1615	@echo  ''
1616	@echo  'Tools:'
1617	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1618	@echo  ''
1619	@echo  'Kernel selftest:'
1620	@echo  '  kselftest         - Build and run kernel selftest'
1621	@echo  '                      Build, install, and boot kernel before'
1622	@echo  '                      running kselftest on it'
1623	@echo  '                      Run as root for full coverage'
1624	@echo  '  kselftest-all     - Build kernel selftest'
1625	@echo  '  kselftest-install - Build and install kernel selftest'
1626	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1627	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1628	@echo  '		      kselftest to existing .config.'
1629	@echo  ''
1630	@echo  'Rust targets:'
1631	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1632	@echo  '		    available and, if not, explains why.'
1633	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1634	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1635	@echo  '		    is formatted, printing a diff otherwise.'
1636	@echo  '  rustdoc	  - Generate Rust documentation'
1637	@echo  '		    (requires kernel .config)'
1638	@echo  '  rusttest        - Runs the Rust tests'
1639	@echo  '                    (requires kernel .config; downloads external repos)'
1640	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1641	@echo  '		    (requires kernel .config)'
1642	@echo  '  dir/file.[os]   - Build specified target only'
1643	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1644	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1645	@echo  '                    The output is not intended to be compilable.'
1646	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1647	@echo  ''
1648	@$(if $(dtstree), \
1649		echo 'Devicetree:'; \
1650		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1651		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1652		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1653		echo '  dt_binding_schemas - Build processed device tree binding schemas'; \
1654		echo '  dtbs_check         - Validate device tree source files';\
1655		echo '')
1656
1657	@echo 'Userspace tools targets:'
1658	@echo '  use "make tools/help"'
1659	@echo '  or  "cd tools; make help"'
1660	@echo  ''
1661	@echo  'Kernel packaging:'
1662	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1663	@echo  ''
1664	@echo  'Documentation targets:'
1665	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1666	@echo  ''
1667	@echo  'Architecture-specific targets ($(SRCARCH)):'
1668	@$(or $(archhelp),\
1669		echo '  No architecture-specific help defined for $(SRCARCH)')
1670	@echo  ''
1671	@$(if $(boards), \
1672		$(foreach b, $(boards), \
1673		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1674		echo '')
1675	@$(if $(board-dirs), \
1676		$(foreach b, $(board-dirs), \
1677		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1678		printf "  %-16s - Show all of the above\\n" help-boards; \
1679		echo '')
1680
1681	@echo  '  make V=n   [targets] 1: verbose build'
1682	@echo  '                       2: give reason for rebuild of target'
1683	@echo  '                       V=1 and V=2 can be combined with V=12'
1684	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1685	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1686	@echo  '                       (sparse by default)'
1687	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1688	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1689	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1690	@echo  '		1: warnings which may be relevant and do not occur too often'
1691	@echo  '		2: warnings which occur quite often but may still be relevant'
1692	@echo  '		3: more obscure warnings, can most likely be ignored'
1693	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1694	@echo  '		e: warnings are being treated as errors'
1695	@echo  '		Multiple levels can be combined with W=12 or W=123'
1696	@$(if $(dtstree), \
1697		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1698		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1699		)
1700	@echo  ''
1701	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1702	@echo  'For further info see the ./README file'
1703
1704
1705help-board-dirs := $(addprefix help-,$(board-dirs))
1706
1707help-boards: $(help-board-dirs)
1708
1709boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1710
1711$(help-board-dirs): help-%:
1712	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1713	@$(if $(boards-per-dir), \
1714		$(foreach b, $(boards-per-dir), \
1715		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1716		echo '')
1717
1718
1719# Documentation targets
1720# ---------------------------------------------------------------------------
1721DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1722	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1723PHONY += $(DOC_TARGETS)
1724$(DOC_TARGETS):
1725	$(Q)$(MAKE) $(build)=Documentation $@
1726
1727
1728# Rust targets
1729# ---------------------------------------------------------------------------
1730
1731# "Is Rust available?" target
1732PHONY += rustavailable
1733rustavailable:
1734	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1735
1736# Documentation target
1737#
1738# Using the singular to avoid running afoul of `no-dot-config-targets`.
1739PHONY += rustdoc
1740rustdoc: prepare
1741	$(Q)$(MAKE) $(build)=rust $@
1742
1743# Testing target
1744PHONY += rusttest
1745rusttest: prepare
1746	$(Q)$(MAKE) $(build)=rust $@
1747
1748# Formatting targets
1749PHONY += rustfmt rustfmtcheck
1750
1751# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1752#
1753# We match using absolute paths since `find` does not resolve them
1754# when matching, which is a problem when e.g. `srctree` is `..`.
1755# We `grep` afterwards in order to remove the directory entry itself.
1756rustfmt:
1757	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1758		-o -path $(abs_srctree)/rust/alloc -prune \
1759		-o -path $(abs_objtree)/rust/test -prune \
1760		| grep -Fv $(abs_srctree)/rust/alloc \
1761		| grep -Fv $(abs_objtree)/rust/test \
1762		| grep -Fv generated \
1763		| xargs $(RUSTFMT) $(rustfmt_flags)
1764
1765rustfmtcheck: rustfmt_flags = --check
1766rustfmtcheck: rustfmt
1767
1768# Misc
1769# ---------------------------------------------------------------------------
1770
1771PHONY += misc-check
1772misc-check:
1773	$(Q)$(srctree)/scripts/misc-check
1774
1775all: misc-check
1776
1777PHONY += scripts_gdb
1778scripts_gdb: prepare0
1779	$(Q)$(MAKE) $(build)=scripts/gdb
1780	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1781
1782ifdef CONFIG_GDB_SCRIPTS
1783all: scripts_gdb
1784endif
1785
1786else # KBUILD_EXTMOD
1787
1788filechk_kernel.release = echo $(KERNELRELEASE)
1789
1790###
1791# External module support.
1792# When building external modules the kernel used as basis is considered
1793# read-only, and no consistency checks are made and the make
1794# system is not used on the basis kernel. If updates are required
1795# in the basis kernel ordinary make commands (without M=...) must be used.
1796
1797# We are always building only modules.
1798KBUILD_BUILTIN :=
1799KBUILD_MODULES := 1
1800
1801build-dir := $(KBUILD_EXTMOD)
1802
1803compile_commands.json: $(extmod_prefix)compile_commands.json
1804PHONY += compile_commands.json
1805
1806clean-dirs := $(KBUILD_EXTMOD)
1807clean: private rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1808	$(KBUILD_EXTMOD)/compile_commands.json
1809
1810PHONY += prepare
1811# now expand this into a simple variable to reduce the cost of shell evaluations
1812prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1813prepare:
1814	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1815		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1816		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1817		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1818	fi
1819
1820PHONY += help
1821help:
1822	@echo  '  Building external modules.'
1823	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1824	@echo  ''
1825	@echo  '  modules         - default target, build the module(s)'
1826	@echo  '  modules_install - install the module'
1827	@echo  '  clean           - remove generated files in module directory only'
1828	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1829	@echo  ''
1830
1831ifndef CONFIG_MODULES
1832modules modules_install: __external_modules_error
1833__external_modules_error:
1834	@echo >&2 '***'
1835	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1836	@echo >&2 '*** You cannot build or install external modules.'
1837	@echo >&2 '***'
1838	@false
1839endif
1840
1841endif # KBUILD_EXTMOD
1842
1843# ---------------------------------------------------------------------------
1844# Modules
1845
1846PHONY += modules modules_install modules_sign modules_prepare
1847
1848modules_install:
1849	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1850	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1851
1852ifeq ($(CONFIG_MODULE_SIG),y)
1853# modules_sign is a subset of modules_install.
1854# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1855modules_sign: modules_install
1856	@:
1857else
1858modules_sign:
1859	@echo >&2 '***'
1860	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1861	@echo >&2 '***'
1862	@false
1863endif
1864
1865ifdef CONFIG_MODULES
1866
1867$(MODORDER): $(build-dir)
1868	@:
1869
1870# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1871# This is solely useful to speed up test compiles.
1872modules: modpost
1873ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1874	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1875endif
1876
1877PHONY += modules_check
1878modules_check: $(MODORDER)
1879	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1880
1881else # CONFIG_MODULES
1882
1883modules:
1884	@:
1885
1886KBUILD_MODULES :=
1887
1888endif # CONFIG_MODULES
1889
1890PHONY += modpost
1891modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1892	 $(if $(KBUILD_MODULES), modules_check)
1893	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1894
1895# Single targets
1896# ---------------------------------------------------------------------------
1897# To build individual files in subdirectories, you can do like this:
1898#
1899#   make foo/bar/baz.s
1900#
1901# The supported suffixes for single-target are listed in 'single-targets'
1902#
1903# To build only under specific subdirectories, you can do like this:
1904#
1905#   make foo/bar/baz/
1906
1907ifdef single-build
1908
1909# .ko is special because modpost is needed
1910single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1911single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1912		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1913
1914$(single-ko): single_modules
1915	@:
1916$(single-no-ko): $(build-dir)
1917	@:
1918
1919# Remove MODORDER when done because it is not the real one.
1920PHONY += single_modules
1921single_modules: $(single-no-ko) modules_prepare
1922	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1923	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1924ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1925	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1926endif
1927	$(Q)rm -f $(MODORDER)
1928
1929single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1930
1931KBUILD_MODULES := 1
1932
1933endif
1934
1935# Preset locale variables to speed up the build process. Limit locale
1936# tweaks to this spot to avoid wrong language settings when running
1937# make menuconfig etc.
1938# Error messages still appears in the original language
1939PHONY += $(build-dir)
1940$(build-dir): prepare
1941	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1942
1943clean-dirs := $(addprefix _clean_, $(clean-dirs))
1944PHONY += $(clean-dirs) clean
1945$(clean-dirs):
1946	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1947
1948clean: $(clean-dirs)
1949	$(call cmd,rmfiles)
1950	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1951		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
1952		-o -name '*.ko.*' \
1953		-o -name '*.dtb' -o -name '*.dtbo' \
1954		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
1955		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
1956		-o -name '*.dwo' -o -name '*.lst' \
1957		-o -name '*.su' -o -name '*.mod' \
1958		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1959		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1960		-o -name '*.asn1.[ch]' \
1961		-o -name '*.symtypes' -o -name 'modules.order' \
1962		-o -name '*.c.[012]*.*' \
1963		-o -name '*.ll' \
1964		-o -name '*.gcno' \
1965		\) -type f -print \
1966		-o -name '.tmp_*' -print \
1967		| xargs rm -rf
1968
1969# Generate tags for editors
1970# ---------------------------------------------------------------------------
1971quiet_cmd_tags = GEN     $@
1972      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1973
1974tags TAGS cscope gtags: FORCE
1975	$(call cmd,tags)
1976
1977# Generate rust-project.json (a file that describes the structure of non-Cargo
1978# Rust projects) for rust-analyzer (an implementation of the Language Server
1979# Protocol).
1980PHONY += rust-analyzer
1981rust-analyzer:
1982	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1983	$(Q)$(MAKE) $(build)=rust $@
1984
1985# Script to generate missing namespace dependencies
1986# ---------------------------------------------------------------------------
1987
1988PHONY += nsdeps
1989nsdeps: export KBUILD_NSDEPS=1
1990nsdeps: modules
1991	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1992
1993# Clang Tooling
1994# ---------------------------------------------------------------------------
1995
1996quiet_cmd_gen_compile_commands = GEN     $@
1997      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1998
1999$(extmod_prefix)compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py \
2000	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2001	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2002	$(call if_changed,gen_compile_commands)
2003
2004targets += $(extmod_prefix)compile_commands.json
2005
2006PHONY += clang-tidy clang-analyzer
2007
2008ifdef CONFIG_CC_IS_CLANG
2009quiet_cmd_clang_tools = CHECK   $<
2010      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2011
2012clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2013	$(call cmd,clang_tools)
2014else
2015clang-tidy clang-analyzer:
2016	@echo "$@ requires CC=clang" >&2
2017	@false
2018endif
2019
2020# Scripts to check various things for consistency
2021# ---------------------------------------------------------------------------
2022
2023PHONY += includecheck versioncheck coccicheck export_report
2024
2025includecheck:
2026	find $(srctree)/* $(RCS_FIND_IGNORE) \
2027		-name '*.[hcS]' -type f -print | sort \
2028		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2029
2030versioncheck:
2031	find $(srctree)/* $(RCS_FIND_IGNORE) \
2032		-name '*.[hcS]' -type f -print | sort \
2033		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2034
2035coccicheck:
2036	$(Q)$(BASH) $(srctree)/scripts/$@
2037
2038export_report:
2039	$(PERL) $(srctree)/scripts/export_report.pl
2040
2041PHONY += checkstack kernelrelease kernelversion image_name
2042
2043# UML needs a little special treatment here.  It wants to use the host
2044# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2045# else wants $(ARCH), including people doing cross-builds, which means
2046# that $(SUBARCH) doesn't work here.
2047ifeq ($(ARCH), um)
2048CHECKSTACK_ARCH := $(SUBARCH)
2049else
2050CHECKSTACK_ARCH := $(ARCH)
2051endif
2052MINSTACKSIZE	?= 100
2053checkstack:
2054	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2055	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2056
2057kernelrelease:
2058	@$(filechk_kernel.release)
2059
2060kernelversion:
2061	@echo $(KERNELVERSION)
2062
2063image_name:
2064	@echo $(KBUILD_IMAGE)
2065
2066PHONY += run-command
2067run-command:
2068	$(Q)$(KBUILD_RUN_COMMAND)
2069
2070quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2071      cmd_rmfiles = rm -rf $(rm-files)
2072
2073# read saved command lines for existing targets
2074existing-targets := $(wildcard $(sort $(targets)))
2075
2076-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2077
2078endif # config-build
2079endif # mixed-build
2080endif # need-sub-make
2081
2082PHONY += FORCE
2083FORCE:
2084
2085# Declare the contents of the PHONY variable as phony.  We keep that
2086# information in a variable so we can use it in if_changed and friends.
2087.PHONY: $(PHONY)
2088