xref: /linux/Makefile (revision f4915933947c71f08ed1c5a6c9b4fdbe735e18cf)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 14
4SUBLEVEL = 0
5EXTRAVERSION =
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_output := $(CURDIR)
44
45ifneq ($(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 := $(M)
135endif
136
137ifeq ("$(origin MO)", "command line")
138  KBUILD_EXTMOD_OUTPUT := $(MO)
139endif
140
141$(if $(word 2, $(KBUILD_EXTMOD)), \
142	$(error building multiple external modules is not supported))
143
144$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
145	$(error module directory path cannot contain '$x')))
146
147# Remove trailing slashes
148ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
149KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
150endif
151
152export KBUILD_EXTMOD
153
154# backward compatibility
155KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
156
157ifeq ("$(origin W)", "command line")
158  KBUILD_EXTRA_WARN := $(W)
159endif
160
161export KBUILD_EXTRA_WARN
162
163# Kbuild will save output files in the current working directory.
164# This does not need to match to the root of the kernel source tree.
165#
166# For example, you can do this:
167#
168#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
169#
170# If you want to save output files in a different location, there are
171# two syntaxes to specify it.
172#
173# 1) O=
174# Use "make O=dir/to/store/output/files/"
175#
176# 2) Set KBUILD_OUTPUT
177# Set the environment variable KBUILD_OUTPUT to point to the output directory.
178# export KBUILD_OUTPUT=dir/to/store/output/files/; make
179#
180# The O= assignment takes precedence over the KBUILD_OUTPUT environment
181# variable.
182
183ifeq ("$(origin O)", "command line")
184  KBUILD_OUTPUT := $(O)
185endif
186
187ifdef KBUILD_EXTMOD
188    ifdef KBUILD_OUTPUT
189        objtree := $(realpath $(KBUILD_OUTPUT))
190        $(if $(objtree),,$(error specified kernel directory "$(KBUILD_OUTPUT)" does not exist))
191    else
192        objtree := $(abs_srctree)
193    endif
194    # If Make is invoked from the kernel directory (either kernel
195    # source directory or kernel build directory), external modules
196    # are built in $(KBUILD_EXTMOD) for backward compatibility,
197    # otherwise, built in the current directory.
198    output := $(or $(KBUILD_EXTMOD_OUTPUT),$(if $(filter $(CURDIR),$(objtree) $(abs_srctree)),$(KBUILD_EXTMOD)))
199    # KBUILD_EXTMOD might be a relative path. Remember its absolute path before
200    # Make changes the working directory.
201    srcroot := $(realpath $(KBUILD_EXTMOD))
202    $(if $(srcroot),,$(error specified external module directory "$(KBUILD_EXTMOD)" does not exist))
203else
204    objtree := .
205    output := $(KBUILD_OUTPUT)
206endif
207
208export objtree srcroot
209
210# Do we want to change the working directory?
211ifneq ($(output),)
212# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
213$(shell mkdir -p "$(output)")
214# $(realpath ...) resolves symlinks
215abs_output := $(realpath $(output))
216$(if $(abs_output),,$(error failed to create output directory "$(output)"))
217endif
218
219ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
220$(error source directory cannot contain spaces or colons)
221endif
222
223export sub_make_done := 1
224
225endif # sub_make_done
226
227ifeq ($(abs_output),$(CURDIR))
228# Suppress "Entering directory ..." if we are at the final work directory.
229no-print-directory := --no-print-directory
230else
231# Recursion to show "Entering directory ..."
232need-sub-make := 1
233endif
234
235ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
236# If --no-print-directory is unset, recurse once again to set it.
237# You may end up recursing into __sub-make twice. This is needed due to the
238# behavior change in GNU Make 4.4.1.
239need-sub-make := 1
240endif
241
242ifeq ($(need-sub-make),1)
243
244PHONY += $(MAKECMDGOALS) __sub-make
245
246$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
247	@:
248
249# Invoke a second make in the output directory, passing relevant variables
250__sub-make:
251	$(Q)$(MAKE) $(no-print-directory) -C $(abs_output) \
252	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
253
254else # need-sub-make
255
256# We process the rest of the Makefile if this is the final invocation of make
257
258ifndef KBUILD_EXTMOD
259srcroot := $(abs_srctree)
260endif
261
262ifeq ($(srcroot),$(CURDIR))
263building_out_of_srctree :=
264else
265export building_out_of_srctree := 1
266endif
267
268ifdef KBUILD_ABS_SRCTREE
269    # Do nothing. Use the absolute path.
270else ifeq ($(srcroot),$(CURDIR))
271    # Building in the source.
272    srcroot := .
273else ifeq ($(srcroot)/,$(dir $(CURDIR)))
274    # Building in a subdirectory of the source.
275    srcroot := ..
276endif
277
278export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot))
279
280ifdef building_out_of_srctree
281export VPATH := $(srcroot)
282else
283VPATH :=
284endif
285
286# To make sure we do not include .config for any of the *config targets
287# catch them early, and hand them over to scripts/kconfig/Makefile
288# It is allowed to specify more targets when calling make, including
289# mixing *config targets and build targets.
290# For example 'make oldconfig all'.
291# Detect when mixed targets is specified, and make a second invocation
292# of make so .config is not included in this case either (for *config).
293
294version_h := include/generated/uapi/linux/version.h
295
296clean-targets := %clean mrproper cleandocs
297no-dot-config-targets := $(clean-targets) \
298			 cscope gtags TAGS tags help% %docs check% coccicheck \
299			 $(version_h) headers headers_% archheaders archscripts \
300			 %asm-generic kernelversion %src-pkg dt_binding_check \
301			 outputmakefile rustavailable rustfmt rustfmtcheck
302no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
303			  image_name
304single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %/
305
306config-build	:=
307mixed-build	:=
308need-config	:= 1
309may-sync-config	:= 1
310single-build	:=
311
312ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
313    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
314        need-config :=
315    endif
316endif
317
318ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
319    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
320        may-sync-config :=
321    endif
322endif
323
324need-compiler := $(may-sync-config)
325
326ifneq ($(KBUILD_EXTMOD),)
327    may-sync-config :=
328endif
329
330ifeq ($(KBUILD_EXTMOD),)
331    ifneq ($(filter %config,$(MAKECMDGOALS)),)
332        config-build := 1
333        ifneq ($(words $(MAKECMDGOALS)),1)
334            mixed-build := 1
335        endif
336    endif
337endif
338
339# We cannot build single targets and the others at the same time
340ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
341    single-build := 1
342    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
343        mixed-build := 1
344    endif
345endif
346
347# For "make -j clean all", "make -j mrproper defconfig all", etc.
348ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
349    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
350        mixed-build := 1
351    endif
352endif
353
354# install and modules_install need also be processed one by one
355ifneq ($(filter install,$(MAKECMDGOALS)),)
356    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
357        mixed-build := 1
358    endif
359endif
360
361ifdef mixed-build
362# ===========================================================================
363# We're called with mixed targets (*config and build targets).
364# Handle them one by one.
365
366PHONY += $(MAKECMDGOALS) __build_one_by_one
367
368$(MAKECMDGOALS): __build_one_by_one
369	@:
370
371__build_one_by_one:
372	$(Q)set -e; \
373	for i in $(MAKECMDGOALS); do \
374		$(MAKE) -f $(srctree)/Makefile $$i; \
375	done
376
377else # !mixed-build
378
379include $(srctree)/scripts/Kbuild.include
380
381# Read KERNELRELEASE from include/config/kernel.release (if it exists)
382KERNELRELEASE = $(call read-file, $(objtree)/include/config/kernel.release)
383KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
384export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
385
386include $(srctree)/scripts/subarch.include
387
388# Cross compiling and selecting different set of gcc/bin-utils
389# ---------------------------------------------------------------------------
390#
391# When performing cross compilation for other architectures ARCH shall be set
392# to the target architecture. (See arch/* for the possibilities).
393# ARCH can be set during invocation of make:
394# make ARCH=arm64
395# Another way is to have ARCH set in the environment.
396# The default ARCH is the host where make is executed.
397
398# CROSS_COMPILE specify the prefix used for all executables used
399# during compilation. Only gcc and related bin-utils executables
400# are prefixed with $(CROSS_COMPILE).
401# CROSS_COMPILE can be set on the command line
402# make CROSS_COMPILE=aarch64-linux-gnu-
403# Alternatively CROSS_COMPILE can be set in the environment.
404# Default value for CROSS_COMPILE is not to prefix executables
405# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
406ARCH		?= $(SUBARCH)
407
408# Architecture as present in compile.h
409UTS_MACHINE 	:= $(ARCH)
410SRCARCH 	:= $(ARCH)
411
412# Additional ARCH settings for x86
413ifeq ($(ARCH),i386)
414        SRCARCH := x86
415endif
416ifeq ($(ARCH),x86_64)
417        SRCARCH := x86
418endif
419
420# Additional ARCH settings for sparc
421ifeq ($(ARCH),sparc32)
422       SRCARCH := sparc
423endif
424ifeq ($(ARCH),sparc64)
425       SRCARCH := sparc
426endif
427
428# Additional ARCH settings for parisc
429ifeq ($(ARCH),parisc64)
430       SRCARCH := parisc
431endif
432
433export cross_compiling :=
434ifneq ($(SRCARCH),$(SUBARCH))
435cross_compiling := 1
436endif
437
438KCONFIG_CONFIG	?= .config
439export KCONFIG_CONFIG
440
441# SHELL used by kbuild
442CONFIG_SHELL := sh
443
444HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
445HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
446HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
447
448ifneq ($(LLVM),)
449ifneq ($(filter %/,$(LLVM)),)
450LLVM_PREFIX := $(LLVM)
451else ifneq ($(filter -%,$(LLVM)),)
452LLVM_SUFFIX := $(LLVM)
453endif
454
455HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
456HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
457else
458HOSTCC	= gcc
459HOSTCXX	= g++
460endif
461HOSTRUSTC = rustc
462HOSTPKG_CONFIG	= pkg-config
463
464KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
465			 -O2 -fomit-frame-pointer -std=gnu11
466KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
467KBUILD_USERLDFLAGS := $(USERLDFLAGS)
468
469# These flags apply to all Rust code in the tree, including the kernel and
470# host programs.
471export rust_common_flags := --edition=2021 \
472			    -Zbinary_dep_depinfo=y \
473			    -Astable_features \
474			    -Dnon_ascii_idents \
475			    -Dunsafe_op_in_unsafe_fn \
476			    -Wmissing_docs \
477			    -Wrust_2018_idioms \
478			    -Wunreachable_pub \
479			    -Wclippy::all \
480			    -Wclippy::ignored_unit_patterns \
481			    -Wclippy::mut_mut \
482			    -Wclippy::needless_bitwise_bool \
483			    -Wclippy::needless_continue \
484			    -Aclippy::needless_lifetimes \
485			    -Wclippy::no_mangle_with_rust_abi \
486			    -Wclippy::undocumented_unsafe_blocks \
487			    -Wclippy::unnecessary_safety_comment \
488			    -Wclippy::unnecessary_safety_doc \
489			    -Wrustdoc::missing_crate_level_docs \
490			    -Wrustdoc::unescaped_backticks
491
492KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
493		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
494KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
495		       -I $(srctree)/scripts/include
496KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
497			-Zallow-features= $(HOSTRUSTFLAGS)
498KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
499KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
500KBUILD_PROCMACROLDFLAGS := $(or $(PROCMACROLDFLAGS),$(KBUILD_HOSTLDFLAGS))
501
502# Make variables (CC, etc...)
503CPP		= $(CC) -E
504ifneq ($(LLVM),)
505CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
506LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
507AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
508NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
509OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
510OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
511READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
512STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
513else
514CC		= $(CROSS_COMPILE)gcc
515LD		= $(CROSS_COMPILE)ld
516AR		= $(CROSS_COMPILE)ar
517NM		= $(CROSS_COMPILE)nm
518OBJCOPY		= $(CROSS_COMPILE)objcopy
519OBJDUMP		= $(CROSS_COMPILE)objdump
520READELF		= $(CROSS_COMPILE)readelf
521STRIP		= $(CROSS_COMPILE)strip
522endif
523RUSTC		= rustc
524RUSTDOC		= rustdoc
525RUSTFMT		= rustfmt
526CLIPPY_DRIVER	= clippy-driver
527BINDGEN		= bindgen
528PAHOLE		= pahole
529RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
530LEX		= flex
531YACC		= bison
532AWK		= awk
533INSTALLKERNEL  := installkernel
534PERL		= perl
535PYTHON3		= python3
536CHECK		= sparse
537BASH		= bash
538KGZIP		= gzip
539KBZIP2		= bzip2
540KLZOP		= lzop
541LZMA		= lzma
542LZ4		= lz4
543XZ		= xz
544ZSTD		= zstd
545
546CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
547		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
548NOSTDINC_FLAGS :=
549CFLAGS_MODULE   =
550RUSTFLAGS_MODULE =
551AFLAGS_MODULE   =
552LDFLAGS_MODULE  =
553CFLAGS_KERNEL	=
554RUSTFLAGS_KERNEL =
555AFLAGS_KERNEL	=
556LDFLAGS_vmlinux =
557
558# Use USERINCLUDE when you must reference the UAPI directories only.
559USERINCLUDE    := \
560		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
561		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
562		-I$(srctree)/include/uapi \
563		-I$(objtree)/include/generated/uapi \
564                -include $(srctree)/include/linux/compiler-version.h \
565                -include $(srctree)/include/linux/kconfig.h
566
567# Use LINUXINCLUDE when you must reference the include/ directory.
568# Needed to be compatible with the O= option
569LINUXINCLUDE    := \
570		-I$(srctree)/arch/$(SRCARCH)/include \
571		-I$(objtree)/arch/$(SRCARCH)/include/generated \
572		-I$(srctree)/include \
573		-I$(objtree)/include \
574		$(USERINCLUDE)
575
576KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
577
578KBUILD_CFLAGS :=
579KBUILD_CFLAGS += -std=gnu11
580KBUILD_CFLAGS += -fshort-wchar
581KBUILD_CFLAGS += -funsigned-char
582KBUILD_CFLAGS += -fno-common
583KBUILD_CFLAGS += -fno-PIE
584KBUILD_CFLAGS += -fno-strict-aliasing
585
586KBUILD_CPPFLAGS := -D__KERNEL__
587KBUILD_RUSTFLAGS := $(rust_common_flags) \
588		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
589		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
590		    -Csymbol-mangling-version=v0 \
591		    -Crelocation-model=static \
592		    -Zfunction-sections=n \
593		    -Wclippy::float_arithmetic
594
595KBUILD_AFLAGS_KERNEL :=
596KBUILD_CFLAGS_KERNEL :=
597KBUILD_RUSTFLAGS_KERNEL :=
598KBUILD_AFLAGS_MODULE  := -DMODULE
599KBUILD_CFLAGS_MODULE  := -DMODULE
600KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
601KBUILD_LDFLAGS_MODULE :=
602KBUILD_LDFLAGS :=
603CLANG_FLAGS :=
604
605ifeq ($(KBUILD_CLIPPY),1)
606	RUSTC_OR_CLIPPY_QUIET := CLIPPY
607	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
608else
609	RUSTC_OR_CLIPPY_QUIET := RUSTC
610	RUSTC_OR_CLIPPY = $(RUSTC)
611endif
612
613# Allows the usage of unstable features in stable compilers.
614export RUSTC_BOOTSTRAP := 1
615
616# Allows finding `.clippy.toml` in out-of-srctree builds.
617export CLIPPY_CONF_DIR := $(srctree)
618
619export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
620export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN
621export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
622export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
623export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
624export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
625export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS KBUILD_PROCMACROLDFLAGS LDFLAGS_MODULE
626export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
627
628export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
629export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
630export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
631export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
632export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
633export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
634
635# Files to ignore in find ... statements
636
637export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
638			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
639			  -prune -o
640
641# ===========================================================================
642# Rules shared between *config targets and build targets
643
644# Basic helpers built in scripts/basic/
645PHONY += scripts_basic
646scripts_basic:
647	$(Q)$(MAKE) $(build)=scripts/basic
648
649PHONY += outputmakefile
650ifdef building_out_of_srctree
651# Before starting out-of-tree build, make sure the source tree is clean.
652# outputmakefile generates a Makefile in the output directory, if using a
653# separate output directory. This allows convenient use of make in the
654# output directory.
655# At the same time when output Makefile generated, generate .gitignore to
656# ignore whole output directory
657
658ifdef KBUILD_EXTMOD
659print_env_for_makefile = \
660	echo "export KBUILD_OUTPUT = $(objtree)"; \
661	echo "export KBUILD_EXTMOD = $(realpath $(srcroot))" ; \
662	echo "export KBUILD_EXTMOD_OUTPUT = $(CURDIR)"
663else
664print_env_for_makefile = \
665	echo "export KBUILD_OUTPUT = $(CURDIR)"
666endif
667
668quiet_cmd_makefile = GEN     Makefile
669      cmd_makefile = { \
670	echo "\# Automatically generated by $(abs_srctree)/Makefile: don't edit"; \
671	$(print_env_for_makefile); \
672	echo "include $(abs_srctree)/Makefile"; \
673	} > Makefile
674
675outputmakefile:
676ifeq ($(KBUILD_EXTMOD),)
677	@if [ -f $(srctree)/.config -o \
678		 -d $(srctree)/include/config -o \
679		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
680		echo >&2 "***"; \
681		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
682		echo >&2 "*** in $(abs_srctree)";\
683		echo >&2 "***"; \
684		false; \
685	fi
686else
687	@if [ -f $(srcroot)/modules.order ]; then \
688		echo >&2 "***"; \
689		echo >&2 "*** The external module source tree is not clean."; \
690		echo >&2 "*** Please run 'make -C $(abs_srctree) M=$(realpath $(srcroot)) clean'"; \
691		echo >&2 "***"; \
692		false; \
693	fi
694endif
695	$(Q)ln -fsn $(srcroot) source
696	$(call cmd,makefile)
697	$(Q)test -e .gitignore || \
698	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
699endif
700
701# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
702# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
703# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they
704# need export), and from include/config/auto.conf.cmd to detect the compiler
705# upgrade.
706CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
707RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
708
709ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
710include $(srctree)/scripts/Makefile.clang
711endif
712
713# Include this also for config targets because some architectures need
714# cc-cross-prefix to determine CROSS_COMPILE.
715ifdef need-compiler
716include $(srctree)/scripts/Makefile.compiler
717endif
718
719ifdef config-build
720# ===========================================================================
721# *config targets only - make sure prerequisites are updated, and descend
722# in scripts/kconfig to make the *config target
723
724# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
725# KBUILD_DEFCONFIG may point out an alternative default configuration
726# used for 'make defconfig'
727include $(srctree)/arch/$(SRCARCH)/Makefile
728export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
729
730config: outputmakefile scripts_basic FORCE
731	$(Q)$(MAKE) $(build)=scripts/kconfig $@
732
733%config: outputmakefile scripts_basic FORCE
734	$(Q)$(MAKE) $(build)=scripts/kconfig $@
735
736else #!config-build
737# ===========================================================================
738# Build targets only - this includes vmlinux, arch-specific targets, clean
739# targets and others. In general all targets except *config targets.
740
741# If building an external module we do not care about the all: rule
742# but instead __all depend on modules
743PHONY += all
744ifeq ($(KBUILD_EXTMOD),)
745__all: all
746else
747__all: modules
748endif
749
750targets :=
751
752# Decide whether to build built-in, modular, or both.
753# Normally, just do built-in.
754
755KBUILD_MODULES :=
756KBUILD_BUILTIN := 1
757
758# If we have only "make modules", don't compile built-in objects.
759ifeq ($(MAKECMDGOALS),modules)
760  KBUILD_BUILTIN :=
761endif
762
763# If we have "make <whatever> modules", compile modules
764# in addition to whatever we do anyway.
765# Just "make" or "make all" shall build modules as well
766
767ifneq ($(filter all modules nsdeps compile_commands.json clang-%,$(MAKECMDGOALS)),)
768  KBUILD_MODULES := 1
769endif
770
771ifeq ($(MAKECMDGOALS),)
772  KBUILD_MODULES := 1
773endif
774
775export KBUILD_MODULES KBUILD_BUILTIN
776
777ifdef need-config
778include $(objtree)/include/config/auto.conf
779endif
780
781ifeq ($(KBUILD_EXTMOD),)
782# Objects we will link into vmlinux / subdirs we need to visit
783core-y		:=
784drivers-y	:=
785libs-y		:= lib/
786endif # KBUILD_EXTMOD
787
788# The all: target is the default when no target is given on the
789# command line.
790# This allow a user to issue only 'make' to build a kernel including modules
791# Defaults to vmlinux, but the arch makefile usually adds further targets
792all: vmlinux
793
794CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
795ifdef CONFIG_CC_IS_GCC
796CFLAGS_GCOV	+= -fno-tree-loop-im
797endif
798export CFLAGS_GCOV
799
800# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
801ifdef CONFIG_FUNCTION_TRACER
802  CC_FLAGS_FTRACE := -pg
803endif
804
805include $(srctree)/arch/$(SRCARCH)/Makefile
806
807ifdef need-config
808ifdef may-sync-config
809# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
810# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
811# because some architectures define CROSS_COMPILE there.
812include include/config/auto.conf.cmd
813
814$(KCONFIG_CONFIG):
815	@echo >&2 '***'
816	@echo >&2 '*** Configuration file "$@" not found!'
817	@echo >&2 '***'
818	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
819	@echo >&2 '*** "make menuconfig" or "make xconfig").'
820	@echo >&2 '***'
821	@/bin/false
822
823# The actual configuration files used during the build are stored in
824# include/generated/ and include/config/. Update them if .config is newer than
825# include/config/auto.conf (which mirrors .config).
826#
827# This exploits the 'multi-target pattern rule' trick.
828# The syncconfig should be executed only once to make all the targets.
829# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
830#
831# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
832# so you cannot notice that Kconfig is waiting for the user input.
833%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
834	$(Q)$(kecho) "  SYNC    $@"
835	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
836else # !may-sync-config
837# External modules and some install targets need include/generated/autoconf.h
838# and include/config/auto.conf but do not care if they are up-to-date.
839# Use auto.conf to show the error message
840
841checked-configs := $(addprefix $(objtree)/, include/generated/autoconf.h include/generated/rustc_cfg include/config/auto.conf)
842missing-configs := $(filter-out $(wildcard $(checked-configs)), $(checked-configs))
843
844ifdef missing-configs
845PHONY += $(objtree)/include/config/auto.conf
846
847$(objtree)/include/config/auto.conf:
848	@echo   >&2 '***'
849	@echo   >&2 '***  ERROR: Kernel configuration is invalid. The following files are missing:'
850	@printf >&2 '***    - %s\n' $(missing-configs)
851	@echo   >&2 '***  Run "make oldconfig && make prepare" on kernel source to fix it.'
852	@echo   >&2 '***'
853	@/bin/false
854endif
855
856endif # may-sync-config
857endif # need-config
858
859KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
860
861ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
862KBUILD_CFLAGS += -O2
863KBUILD_RUSTFLAGS += -Copt-level=2
864else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
865KBUILD_CFLAGS += -Os
866KBUILD_RUSTFLAGS += -Copt-level=s
867endif
868
869# Always set `debug-assertions` and `overflow-checks` because their default
870# depends on `opt-level` and `debug-assertions`, respectively.
871KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
872KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
873
874# Tell gcc to never replace conditional load with a non-conditional one
875ifdef CONFIG_CC_IS_GCC
876# gcc-10 renamed --param=allow-store-data-races=0 to
877# -fno-allow-store-data-races.
878KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
879KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
880endif
881
882ifdef CONFIG_READABLE_ASM
883# Disable optimizations that make assembler listings hard to read.
884# reorder blocks reorders the control in the function
885# ipa clone creates specialized cloned functions
886# partial inlining inlines only parts of functions
887KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
888endif
889
890stackp-flags-y                                    := -fno-stack-protector
891stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
892stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
893
894KBUILD_CFLAGS += $(stackp-flags-y)
895
896KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
897KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
898
899ifdef CONFIG_FRAME_POINTER
900KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
901KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
902else
903# Some targets (ARM with Thumb2, for example), can't be built with frame
904# pointers.  For those, we don't have FUNCTION_TRACER automatically
905# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
906# incompatible with -fomit-frame-pointer with current GCC, so we don't use
907# -fomit-frame-pointer with FUNCTION_TRACER.
908# In the Rust target specification, "frame-pointer" is set explicitly
909# to "may-omit".
910ifndef CONFIG_FUNCTION_TRACER
911KBUILD_CFLAGS	+= -fomit-frame-pointer
912endif
913endif
914
915# Initialize all stack variables with a 0xAA pattern.
916ifdef CONFIG_INIT_STACK_ALL_PATTERN
917KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
918endif
919
920# Initialize all stack variables with a zero value.
921ifdef CONFIG_INIT_STACK_ALL_ZERO
922KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
923ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
924# https://github.com/llvm/llvm-project/issues/44842
925CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
926export CC_AUTO_VAR_INIT_ZERO_ENABLER
927KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
928endif
929endif
930
931# While VLAs have been removed, GCC produces unreachable stack probes
932# for the randomize_kstack_offset feature. Disable it for all compilers.
933KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
934
935# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
936ifdef CONFIG_ZERO_CALL_USED_REGS
937KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
938endif
939
940ifdef CONFIG_FUNCTION_TRACER
941ifdef CONFIG_FTRACE_MCOUNT_USE_CC
942  CC_FLAGS_FTRACE	+= -mrecord-mcount
943  ifdef CONFIG_HAVE_NOP_MCOUNT
944    ifeq ($(call cc-option-yn, -mnop-mcount),y)
945      CC_FLAGS_FTRACE	+= -mnop-mcount
946      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
947    endif
948  endif
949endif
950ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
951  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
952    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
953  endif
954endif
955ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
956  ifdef CONFIG_HAVE_C_RECORDMCOUNT
957    BUILD_C_RECORDMCOUNT := y
958    export BUILD_C_RECORDMCOUNT
959  endif
960endif
961ifdef CONFIG_HAVE_FENTRY
962  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
963  ifeq ($(call cc-option-yn, -mfentry),y)
964    CC_FLAGS_FTRACE	+= -mfentry
965    CC_FLAGS_USING	+= -DCC_USING_FENTRY
966  endif
967endif
968export CC_FLAGS_FTRACE
969KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
970KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
971endif
972
973# We trigger additional mismatches with less inlining
974ifdef CONFIG_DEBUG_SECTION_MISMATCH
975KBUILD_CFLAGS += -fno-inline-functions-called-once
976endif
977
978# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
979ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
980KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
981KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
982LDFLAGS_vmlinux += --gc-sections
983endif
984
985ifdef CONFIG_SHADOW_CALL_STACK
986ifndef CONFIG_DYNAMIC_SCS
987CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
988KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
989KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack
990endif
991export CC_FLAGS_SCS
992endif
993
994ifdef CONFIG_LTO_CLANG
995ifdef CONFIG_LTO_CLANG_THIN
996CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
997else
998CC_FLAGS_LTO	:= -flto
999endif
1000CC_FLAGS_LTO	+= -fvisibility=hidden
1001
1002# Limit inlining across translation units to reduce binary size
1003KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
1004endif
1005
1006ifdef CONFIG_LTO
1007KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
1008KBUILD_AFLAGS	+= -fno-lto
1009export CC_FLAGS_LTO
1010endif
1011
1012ifdef CONFIG_CFI_CLANG
1013CC_FLAGS_CFI	:= -fsanitize=kcfi
1014ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
1015	CC_FLAGS_CFI	+= -fsanitize-cfi-icall-experimental-normalize-integers
1016endif
1017ifdef CONFIG_FINEIBT_BHI
1018	CC_FLAGS_CFI	+= -fsanitize-kcfi-arity
1019endif
1020ifdef CONFIG_RUST
1021	# Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects
1022	# CONFIG_CFI_ICALL_NORMALIZE_INTEGERS.
1023	RUSTC_FLAGS_CFI   := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers
1024	KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI)
1025	export RUSTC_FLAGS_CFI
1026endif
1027KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1028export CC_FLAGS_CFI
1029endif
1030
1031# Architectures can define flags to add/remove for floating-point support
1032CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
1033export CC_FLAGS_FPU
1034export CC_FLAGS_NO_FPU
1035
1036ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1037# Set the minimal function alignment. Use the newer GCC option
1038# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
1039# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
1040ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
1041KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
1042else
1043KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1044endif
1045endif
1046
1047# arch Makefile may override CC so keep this after arch Makefile is included
1048NOSTDINC_FLAGS += -nostdinc
1049
1050# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
1051# the kernel uses only C99 flexible arrays for dynamically sized trailing
1052# arrays. Enforce this for everything that may examine structure sizes and
1053# perform bounds checking.
1054KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
1055
1056#Currently, disable -Wstringop-overflow for GCC 11, globally.
1057KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
1058KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
1059
1060# disable invalid "can't wrap" optimizations for signed / pointers
1061KBUILD_CFLAGS	+= -fno-strict-overflow
1062
1063# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1064KBUILD_CFLAGS  += -fno-stack-check
1065
1066# conserve stack if available
1067ifdef CONFIG_CC_IS_GCC
1068KBUILD_CFLAGS   += -fconserve-stack
1069endif
1070
1071# change __FILE__ to the relative path to the source directory
1072ifdef building_out_of_srctree
1073KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srcroot)/=)
1074endif
1075
1076# include additional Makefiles when needed
1077include-y			:= scripts/Makefile.extrawarn
1078include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1079include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1080include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1081include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1082include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1083include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1084include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1085include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1086include-$(CONFIG_AUTOFDO_CLANG)	+= scripts/Makefile.autofdo
1087include-$(CONFIG_PROPELLER_CLANG)	+= scripts/Makefile.propeller
1088include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1089
1090include $(addprefix $(srctree)/, $(include-y))
1091
1092# scripts/Makefile.gcc-plugins is intentionally included last.
1093# Do not add $(call cc-option,...) below this line. When you build the kernel
1094# from the clean source tree, the GCC plugins do not exist at this point.
1095
1096# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1097KBUILD_CPPFLAGS += $(KCPPFLAGS)
1098KBUILD_AFLAGS   += $(KAFLAGS)
1099KBUILD_CFLAGS   += $(KCFLAGS)
1100KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1101
1102KBUILD_LDFLAGS_MODULE += --build-id=sha1
1103LDFLAGS_vmlinux += --build-id=sha1
1104
1105KBUILD_LDFLAGS	+= -z noexecstack
1106ifeq ($(CONFIG_LD_IS_BFD),y)
1107KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1108endif
1109
1110ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1111LDFLAGS_vmlinux	+= -X
1112endif
1113
1114ifeq ($(CONFIG_RELR),y)
1115# ld.lld before 15 did not support -z pack-relative-relocs.
1116LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1117endif
1118
1119# We never want expected sections to be placed heuristically by the
1120# linker. All sections should be explicitly named in the linker script.
1121ifdef CONFIG_LD_ORPHAN_WARN
1122LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1123endif
1124
1125# Align the bit size of userspace programs with the kernel
1126KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1127KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1128
1129# userspace programs are linked via the compiler, use the correct linker
1130ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_LD_IS_LLD),yy)
1131KBUILD_USERLDFLAGS += --ld-path=$(LD)
1132endif
1133
1134# make the checker run with the right architecture
1135CHECKFLAGS += --arch=$(ARCH)
1136
1137# insure the checker run with the right endianness
1138CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1139
1140# the checker needs the correct machine size
1141CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1142
1143# Default kernel image to build when no specific target is given.
1144# KBUILD_IMAGE may be overruled on the command line or
1145# set in the environment
1146# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1147# this default value
1148export KBUILD_IMAGE ?= vmlinux
1149
1150#
1151# INSTALL_PATH specifies where to place the updated kernel and system map
1152# images. Default is /boot, but you can set it to other values
1153export	INSTALL_PATH ?= /boot
1154
1155#
1156# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1157# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1158# an argument if needed. Otherwise it defaults to the kernel install path
1159#
1160export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1161
1162#
1163# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1164# relocations required by build roots.  This is not defined in the
1165# makefile but the argument can be passed to make if needed.
1166#
1167
1168MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1169export MODLIB
1170
1171PHONY += prepare0
1172
1173ifeq ($(KBUILD_EXTMOD),)
1174
1175build-dir	:= .
1176clean-dirs	:= $(sort . Documentation \
1177		     $(patsubst %/,%,$(filter %/, $(core-) \
1178			$(drivers-) $(libs-))))
1179
1180export ARCH_CORE	:= $(core-y)
1181export ARCH_LIB		:= $(filter %/, $(libs-y))
1182export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1183# Externally visible symbols (used by link-vmlinux.sh)
1184
1185KBUILD_VMLINUX_OBJS := ./built-in.a
1186ifdef CONFIG_MODULES
1187KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1188KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1189else
1190KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1191endif
1192
1193export KBUILD_VMLINUX_LIBS
1194export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1195
1196ifdef CONFIG_TRIM_UNUSED_KSYMS
1197# For the kernel to actually contain only the needed exported symbols,
1198# we have to build modules as well to determine what those symbols are.
1199KBUILD_MODULES := 1
1200endif
1201
1202# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1203quiet_cmd_ar_vmlinux.a = AR      $@
1204      cmd_ar_vmlinux.a = \
1205	rm -f $@; \
1206	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1207	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1208
1209targets += vmlinux.a
1210vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1211	$(call if_changed,ar_vmlinux.a)
1212
1213PHONY += vmlinux_o
1214vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1215	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1216
1217vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1218	@:
1219
1220PHONY += vmlinux
1221# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1222# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1223# unrelated; the decompressors just happen to have the same base name,
1224# arch/*/boot/compressed/vmlinux.
1225# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1226#
1227# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1228#   https://savannah.gnu.org/bugs/?61463
1229# For Make > 4.4, the following simple code will work:
1230#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1231vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1232vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1233vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1234	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1235
1236# The actual objects are generated when descending,
1237# make sure no implicit rule kicks in
1238$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1239
1240ifeq ($(origin KERNELRELEASE),file)
1241filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1242else
1243filechk_kernel.release = echo $(KERNELRELEASE)
1244endif
1245
1246# Store (new) KERNELRELEASE string in include/config/kernel.release
1247include/config/kernel.release: FORCE
1248	$(call filechk,kernel.release)
1249
1250# Additional helpers built in scripts/
1251# Carefully list dependencies so we do not try to build scripts twice
1252# in parallel
1253PHONY += scripts
1254scripts: scripts_basic scripts_dtc
1255	$(Q)$(MAKE) $(build)=$(@)
1256
1257# Things we need to do before we recursively start building the kernel
1258# or the modules are listed in "prepare".
1259# A multi level approach is used. prepareN is processed before prepareN-1.
1260# archprepare is used in arch Makefiles and when processed asm symlink,
1261# version.h and scripts_basic is processed / created.
1262
1263PHONY += prepare archprepare
1264
1265archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1266	asm-generic $(version_h) include/generated/utsrelease.h \
1267	include/generated/compile.h include/generated/autoconf.h \
1268	include/generated/rustc_cfg remove-stale-files
1269
1270prepare0: archprepare
1271	$(Q)$(MAKE) $(build)=scripts/mod
1272	$(Q)$(MAKE) $(build)=. prepare
1273
1274# All the preparing..
1275prepare: prepare0
1276ifdef CONFIG_RUST
1277	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1278	$(Q)$(MAKE) $(build)=rust
1279endif
1280
1281PHONY += remove-stale-files
1282remove-stale-files:
1283	$(Q)$(srctree)/scripts/remove-stale-files
1284
1285# Support for using generic headers in asm-generic
1286asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1287
1288PHONY += asm-generic uapi-asm-generic
1289asm-generic: uapi-asm-generic
1290	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1291	generic=include/asm-generic
1292uapi-asm-generic:
1293	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1294	generic=include/uapi/asm-generic
1295
1296# Generate some files
1297# ---------------------------------------------------------------------------
1298
1299# KERNELRELEASE can change from a few different places, meaning version.h
1300# needs to be updated, so this check is forced on all builds
1301
1302uts_len := 64
1303define filechk_utsrelease.h
1304	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1305	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1306	  exit 1;                                                         \
1307	fi;                                                               \
1308	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1309endef
1310
1311define filechk_version.h
1312	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1313		echo \#define LINUX_VERSION_CODE $(shell                 \
1314		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1315	else                                                             \
1316		echo \#define LINUX_VERSION_CODE $(shell                 \
1317		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1318	fi;                                                              \
1319	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1320	((c) > 255 ? 255 : (c)))';                                       \
1321	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1322	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1323	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1324endef
1325
1326$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1327$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1328$(version_h): FORCE
1329	$(call filechk,version.h)
1330
1331include/generated/utsrelease.h: include/config/kernel.release FORCE
1332	$(call filechk,utsrelease.h)
1333
1334filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1335	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1336
1337include/generated/compile.h: FORCE
1338	$(call filechk,compile.h)
1339
1340PHONY += headerdep
1341headerdep:
1342	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1343	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1344
1345# ---------------------------------------------------------------------------
1346# Kernel headers
1347
1348#Default location for installed headers
1349export INSTALL_HDR_PATH = $(objtree)/usr
1350
1351quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1352      cmd_headers_install = \
1353	mkdir -p $(INSTALL_HDR_PATH); \
1354	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1355	usr/include $(INSTALL_HDR_PATH)
1356
1357PHONY += headers_install
1358headers_install: headers
1359	$(call cmd,headers_install)
1360
1361PHONY += archheaders archscripts
1362
1363hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1364
1365PHONY += headers
1366headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1367	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1368	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1369	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1370
1371ifdef CONFIG_HEADERS_INSTALL
1372prepare: headers
1373endif
1374
1375PHONY += scripts_unifdef
1376scripts_unifdef: scripts_basic
1377	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1378
1379PHONY += scripts_gen_packed_field_checks
1380scripts_gen_packed_field_checks: scripts_basic
1381	$(Q)$(MAKE) $(build)=scripts scripts/gen_packed_field_checks
1382
1383# ---------------------------------------------------------------------------
1384# Install
1385
1386# Many distributions have the custom install script, /sbin/installkernel.
1387# If DKMS is installed, 'make install' will eventually recurse back
1388# to this Makefile to build and install external modules.
1389# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1390
1391quiet_cmd_install = INSTALL $(INSTALL_PATH)
1392      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1393
1394# ---------------------------------------------------------------------------
1395# vDSO install
1396
1397PHONY += vdso_install
1398vdso_install: export INSTALL_FILES = $(vdso-install-y)
1399vdso_install:
1400	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1401
1402# ---------------------------------------------------------------------------
1403# Tools
1404
1405ifdef CONFIG_OBJTOOL
1406prepare: tools/objtool
1407endif
1408
1409ifdef CONFIG_BPF
1410ifdef CONFIG_DEBUG_INFO_BTF
1411prepare: tools/bpf/resolve_btfids
1412endif
1413endif
1414
1415# The tools build system is not a part of Kbuild and tends to introduce
1416# its own unique issues. If you need to integrate a new tool into Kbuild,
1417# please consider locating that tool outside the tools/ tree and using the
1418# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1419# here. See Documentation/kbuild/makefiles.rst for details.
1420
1421PHONY += resolve_btfids_clean
1422
1423resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1424
1425# tools/bpf/resolve_btfids directory might not exist
1426# in output directory, skip its clean in that case
1427resolve_btfids_clean:
1428ifneq ($(wildcard $(resolve_btfids_O)),)
1429	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1430endif
1431
1432tools/: FORCE
1433	$(Q)mkdir -p $(objtree)/tools
1434	$(Q)$(MAKE) LDFLAGS= O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1435
1436tools/%: FORCE
1437	$(Q)mkdir -p $(objtree)/tools
1438	$(Q)$(MAKE) LDFLAGS= O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1439
1440# ---------------------------------------------------------------------------
1441# Kernel selftest
1442
1443PHONY += kselftest
1444kselftest: headers
1445	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1446
1447kselftest-%: headers FORCE
1448	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1449
1450PHONY += kselftest-merge
1451kselftest-merge:
1452	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1453	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1454		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1455	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1456
1457# ---------------------------------------------------------------------------
1458# Devicetree files
1459
1460ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1461dtstree := arch/$(SRCARCH)/boot/dts
1462endif
1463
1464ifneq ($(dtstree),)
1465
1466%.dtb: dtbs_prepare
1467	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1468
1469%.dtbo: dtbs_prepare
1470	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1471
1472PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1473dtbs: dtbs_prepare
1474	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1475
1476# include/config/kernel.release is actually needed when installing DTBs because
1477# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1478# dtbs_install depend on it as dtbs_install may run as root.
1479dtbs_prepare: include/config/kernel.release scripts_dtc
1480
1481ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1482export CHECK_DTBS=y
1483endif
1484
1485ifneq ($(CHECK_DTBS),)
1486dtbs_prepare: dt_binding_schemas
1487endif
1488
1489dtbs_check: dtbs
1490
1491dtbs_install:
1492	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1493
1494ifdef CONFIG_OF_EARLY_FLATTREE
1495all: dtbs
1496endif
1497
1498ifdef CONFIG_GENERIC_BUILTIN_DTB
1499vmlinux: dtbs
1500endif
1501
1502endif
1503
1504PHONY += scripts_dtc
1505scripts_dtc: scripts_basic
1506	$(Q)$(MAKE) $(build)=scripts/dtc
1507
1508ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1509export CHECK_DTBS=y
1510endif
1511
1512PHONY += dt_binding_check dt_binding_schemas
1513dt_binding_check: dt_binding_schemas scripts_dtc
1514	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1515
1516dt_binding_schemas:
1517	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1518
1519PHONY += dt_compatible_check
1520dt_compatible_check: dt_binding_schemas
1521	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1522
1523# ---------------------------------------------------------------------------
1524# Modules
1525
1526ifdef CONFIG_MODULES
1527
1528# By default, build modules as well
1529
1530all: modules
1531
1532# When we're building modules with modversions, we need to consider
1533# the built-in objects during the descend as well, in order to
1534# make sure the checksums are up to date before we record them.
1535ifdef CONFIG_MODVERSIONS
1536  KBUILD_BUILTIN := 1
1537endif
1538
1539# Build modules
1540#
1541
1542# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1543# is an exception.
1544ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1545KBUILD_BUILTIN := 1
1546modules: vmlinux
1547endif
1548
1549modules: modules_prepare
1550
1551# Target to prepare building external modules
1552modules_prepare: prepare
1553	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1554
1555endif # CONFIG_MODULES
1556
1557###
1558# Cleaning is done on three levels.
1559# make clean     Delete most generated files
1560#                Leave enough to build external modules
1561# make mrproper  Delete the current configuration, and all generated files
1562# make distclean Remove editor backup files, patch leftover files and the like
1563
1564# Directories & files removed with 'make clean'
1565CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1566	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1567	       modules.builtin.ranges vmlinux.o.map \
1568	       compile_commands.json rust/test \
1569	       rust-project.json .vmlinux.objs .vmlinux.export.c \
1570               .builtin-dtbs-list .builtin-dtb.S
1571
1572# Directories & files removed with 'make mrproper'
1573MRPROPER_FILES += include/config include/generated          \
1574		  arch/$(SRCARCH)/include/generated .objdiff \
1575		  debian snap tar-install PKGBUILD pacman \
1576		  .config .config.old .version \
1577		  Module.symvers \
1578		  certs/signing_key.pem \
1579		  certs/x509.genkey \
1580		  vmlinux-gdb.py \
1581		  rpmbuild \
1582		  rust/libmacros.so rust/libmacros.dylib
1583
1584# clean - Delete most, but leave enough to build external modules
1585#
1586clean: private rm-files := $(CLEAN_FILES)
1587
1588PHONY += archclean vmlinuxclean
1589
1590vmlinuxclean:
1591	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1592	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1593
1594clean: archclean vmlinuxclean resolve_btfids_clean
1595
1596# mrproper - Delete all generated files, including .config
1597#
1598mrproper: private rm-files := $(MRPROPER_FILES)
1599mrproper-dirs      := $(addprefix _mrproper_,scripts)
1600
1601PHONY += $(mrproper-dirs) mrproper
1602$(mrproper-dirs):
1603	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1604
1605mrproper: clean $(mrproper-dirs)
1606	$(call cmd,rmfiles)
1607	@find . $(RCS_FIND_IGNORE) \
1608		\( -name '*.rmeta' \) \
1609		-type f -print | xargs rm -f
1610
1611# distclean
1612#
1613PHONY += distclean
1614
1615distclean: mrproper
1616	@find . $(RCS_FIND_IGNORE) \
1617		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1618		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1619		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1620		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1621		-type f -print | xargs rm -f
1622
1623
1624# Packaging of the kernel to various formats
1625# ---------------------------------------------------------------------------
1626
1627%src-pkg: FORCE
1628	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1629%pkg: include/config/kernel.release FORCE
1630	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1631
1632# Brief documentation of the typical targets used
1633# ---------------------------------------------------------------------------
1634
1635boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1636boards := $(sort $(notdir $(boards)))
1637board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1638board-dirs := $(sort $(notdir $(board-dirs:/=)))
1639
1640PHONY += help
1641help:
1642	@echo  'Cleaning targets:'
1643	@echo  '  clean		  - Remove most generated files but keep the config and'
1644	@echo  '                    enough build support to build external modules'
1645	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1646	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1647	@echo  ''
1648	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1649	@echo  ''
1650	@echo  'Other generic targets:'
1651	@echo  '  all		  - Build all targets marked with [*]'
1652	@echo  '* vmlinux	  - Build the bare kernel'
1653	@echo  '* modules	  - Build all modules'
1654	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1655	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1656	@echo  '  dir/            - Build all files in dir and below'
1657	@echo  '  dir/file.[ois]  - Build specified target only'
1658	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1659	@echo  '                    (requires compiler support for LLVM assembly generation)'
1660	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1661	@echo  '                    (requires a recent binutils and recent build (System.map))'
1662	@echo  '  dir/file.ko     - Build module including final link'
1663	@echo  '  modules_prepare - Set up for building external modules'
1664	@echo  '  tags/TAGS	  - Generate tags file for editors'
1665	@echo  '  cscope	  - Generate cscope index'
1666	@echo  '  gtags           - Generate GNU GLOBAL index'
1667	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1668	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1669	@echo  '  image_name	  - Output the image name (use with make -s)'
1670	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1671	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1672	 echo  ''
1673	@echo  'Static analysers:'
1674	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1675	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1676	@echo  '  versioncheck    - Sanity check on version.h usage'
1677	@echo  '  includecheck    - Check for duplicate included header files'
1678	@echo  '  headerdep       - Detect inclusion cycles in headers'
1679	@echo  '  coccicheck      - Check with Coccinelle'
1680	@echo  '  clang-analyzer  - Check with clang static analyzer'
1681	@echo  '  clang-tidy      - Check with clang-tidy'
1682	@echo  ''
1683	@echo  'Tools:'
1684	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1685	@echo  ''
1686	@echo  'Kernel selftest:'
1687	@echo  '  kselftest         - Build and run kernel selftest'
1688	@echo  '                      Build, install, and boot kernel before'
1689	@echo  '                      running kselftest on it'
1690	@echo  '                      Run as root for full coverage'
1691	@echo  '  kselftest-all     - Build kernel selftest'
1692	@echo  '  kselftest-install - Build and install kernel selftest'
1693	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1694	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1695	@echo  '		      kselftest to existing .config.'
1696	@echo  ''
1697	@echo  'Rust targets:'
1698	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1699	@echo  '		    available and, if not, explains why.'
1700	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1701	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1702	@echo  '		    is formatted, printing a diff otherwise.'
1703	@echo  '  rustdoc	  - Generate Rust documentation'
1704	@echo  '		    (requires kernel .config)'
1705	@echo  '  rusttest        - Runs the Rust tests'
1706	@echo  '                    (requires kernel .config; downloads external repos)'
1707	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1708	@echo  '		    (requires kernel .config)'
1709	@echo  '  dir/file.[os]   - Build specified target only'
1710	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1711	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1712	@echo  '                    The output is not intended to be compilable.'
1713	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1714	@echo  ''
1715	@$(if $(dtstree), \
1716		echo 'Devicetree:'; \
1717		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1718		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1719		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1720		echo '  dt_binding_schemas - Build processed device tree binding schemas'; \
1721		echo '  dtbs_check         - Validate device tree source files';\
1722		echo '')
1723
1724	@echo 'Userspace tools targets:'
1725	@echo '  use "make tools/help"'
1726	@echo '  or  "cd tools; make help"'
1727	@echo  ''
1728	@echo  'Kernel packaging:'
1729	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1730	@echo  ''
1731	@echo  'Documentation targets:'
1732	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1733	@echo  ''
1734	@echo  'Architecture-specific targets ($(SRCARCH)):'
1735	@$(or $(archhelp),\
1736		echo '  No architecture-specific help defined for $(SRCARCH)')
1737	@echo  ''
1738	@$(if $(boards), \
1739		$(foreach b, $(boards), \
1740		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1741		echo '')
1742	@$(if $(board-dirs), \
1743		$(foreach b, $(board-dirs), \
1744		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1745		printf "  %-16s - Show all of the above\\n" help-boards; \
1746		echo '')
1747
1748	@echo  '  make V=n   [targets] 1: verbose build'
1749	@echo  '                       2: give reason for rebuild of target'
1750	@echo  '                       V=1 and V=2 can be combined with V=12'
1751	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1752	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1753	@echo  '                       (sparse by default)'
1754	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1755	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1756	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1757	@echo  '		1: warnings which may be relevant and do not occur too often'
1758	@echo  '		2: warnings which occur quite often but may still be relevant'
1759	@echo  '		3: more obscure warnings, can most likely be ignored'
1760	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1761	@echo  '		e: warnings are being treated as errors'
1762	@echo  '		Multiple levels can be combined with W=12 or W=123'
1763	@$(if $(dtstree), \
1764		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1765		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1766		)
1767	@echo  ''
1768	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1769	@echo  'For further info see the ./README file'
1770
1771
1772help-board-dirs := $(addprefix help-,$(board-dirs))
1773
1774help-boards: $(help-board-dirs)
1775
1776boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1777
1778$(help-board-dirs): help-%:
1779	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1780	@$(if $(boards-per-dir), \
1781		$(foreach b, $(boards-per-dir), \
1782		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1783		echo '')
1784
1785
1786# Documentation targets
1787# ---------------------------------------------------------------------------
1788DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1789	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1790PHONY += $(DOC_TARGETS)
1791$(DOC_TARGETS):
1792	$(Q)$(MAKE) $(build)=Documentation $@
1793
1794
1795# Rust targets
1796# ---------------------------------------------------------------------------
1797
1798# "Is Rust available?" target
1799PHONY += rustavailable
1800rustavailable:
1801	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1802
1803# Documentation target
1804#
1805# Using the singular to avoid running afoul of `no-dot-config-targets`.
1806PHONY += rustdoc
1807rustdoc: prepare
1808	$(Q)$(MAKE) $(build)=rust $@
1809
1810# Testing target
1811PHONY += rusttest
1812rusttest: prepare
1813	$(Q)$(MAKE) $(build)=rust $@
1814
1815# Formatting targets
1816PHONY += rustfmt rustfmtcheck
1817
1818rustfmt:
1819	$(Q)find $(srctree) $(RCS_FIND_IGNORE) \
1820		-type f -a -name '*.rs' -a ! -name '*generated*' -print \
1821		| xargs $(RUSTFMT) $(rustfmt_flags)
1822
1823rustfmtcheck: rustfmt_flags = --check
1824rustfmtcheck: rustfmt
1825
1826# Misc
1827# ---------------------------------------------------------------------------
1828
1829PHONY += misc-check
1830misc-check:
1831	$(Q)$(srctree)/scripts/misc-check
1832
1833all: misc-check
1834
1835PHONY += scripts_gdb
1836scripts_gdb: prepare0
1837	$(Q)$(MAKE) $(build)=scripts/gdb
1838	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1839
1840ifdef CONFIG_GDB_SCRIPTS
1841all: scripts_gdb
1842endif
1843
1844else # KBUILD_EXTMOD
1845
1846filechk_kernel.release = echo $(KERNELRELEASE)
1847
1848###
1849# External module support.
1850# When building external modules the kernel used as basis is considered
1851# read-only, and no consistency checks are made and the make
1852# system is not used on the basis kernel. If updates are required
1853# in the basis kernel ordinary make commands (without M=...) must be used.
1854
1855# We are always building only modules.
1856KBUILD_BUILTIN :=
1857KBUILD_MODULES := 1
1858
1859build-dir := .
1860
1861clean-dirs := .
1862clean: private rm-files := Module.symvers modules.nsdeps compile_commands.json
1863
1864PHONY += prepare
1865# now expand this into a simple variable to reduce the cost of shell evaluations
1866prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1867prepare:
1868	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1869		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1870		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1871		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1872	fi
1873
1874PHONY += help
1875help:
1876	@echo  '  Building external modules.'
1877	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1878	@echo  ''
1879	@echo  '  modules         - default target, build the module(s)'
1880	@echo  '  modules_install - install the module'
1881	@echo  '  clean           - remove generated files in module directory only'
1882	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1883	@echo  ''
1884
1885ifndef CONFIG_MODULES
1886modules modules_install: __external_modules_error
1887__external_modules_error:
1888	@echo >&2 '***'
1889	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1890	@echo >&2 '*** You cannot build or install external modules.'
1891	@echo >&2 '***'
1892	@false
1893endif
1894
1895endif # KBUILD_EXTMOD
1896
1897# ---------------------------------------------------------------------------
1898# Modules
1899
1900PHONY += modules modules_install modules_sign modules_prepare
1901
1902modules_install:
1903	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1904	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1905
1906ifeq ($(CONFIG_MODULE_SIG),y)
1907# modules_sign is a subset of modules_install.
1908# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1909modules_sign: modules_install
1910	@:
1911else
1912modules_sign:
1913	@echo >&2 '***'
1914	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1915	@echo >&2 '***'
1916	@false
1917endif
1918
1919ifdef CONFIG_MODULES
1920
1921modules.order: $(build-dir)
1922	@:
1923
1924# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1925# This is solely useful to speed up test compiles.
1926modules: modpost
1927ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1928	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1929endif
1930
1931PHONY += modules_check
1932modules_check: modules.order
1933	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1934
1935else # CONFIG_MODULES
1936
1937modules:
1938	@:
1939
1940KBUILD_MODULES :=
1941
1942endif # CONFIG_MODULES
1943
1944PHONY += modpost
1945modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1946	 $(if $(KBUILD_MODULES), modules_check)
1947	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1948
1949# Single targets
1950# ---------------------------------------------------------------------------
1951# To build individual files in subdirectories, you can do like this:
1952#
1953#   make foo/bar/baz.s
1954#
1955# The supported suffixes for single-target are listed in 'single-targets'
1956#
1957# To build only under specific subdirectories, you can do like this:
1958#
1959#   make foo/bar/baz/
1960
1961ifdef single-build
1962
1963# .ko is special because modpost is needed
1964single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1965single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1966		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1967
1968$(single-ko): single_modules
1969	@:
1970$(single-no-ko): $(build-dir)
1971	@:
1972
1973# Remove modules.order when done because it is not the real one.
1974PHONY += single_modules
1975single_modules: $(single-no-ko) modules_prepare
1976	$(Q){ $(foreach m, $(single-ko), echo $(m:%.ko=%.o);) } > modules.order
1977	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1978ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1979	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1980endif
1981	$(Q)rm -f modules.order
1982
1983single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1984
1985KBUILD_MODULES := 1
1986
1987endif
1988
1989prepare: outputmakefile
1990
1991# Preset locale variables to speed up the build process. Limit locale
1992# tweaks to this spot to avoid wrong language settings when running
1993# make menuconfig etc.
1994# Error messages still appears in the original language
1995PHONY += $(build-dir)
1996$(build-dir): prepare
1997	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1998
1999clean-dirs := $(addprefix _clean_, $(clean-dirs))
2000PHONY += $(clean-dirs) clean
2001$(clean-dirs):
2002	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2003
2004clean: $(clean-dirs)
2005	$(call cmd,rmfiles)
2006	@find . $(RCS_FIND_IGNORE) \
2007		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2008		-o -name '*.ko.*' \
2009		-o -name '*.dtb' -o -name '*.dtbo' \
2010		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2011		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
2012		-o -name '*.dwo' -o -name '*.lst' \
2013		-o -name '*.su' -o -name '*.mod' \
2014		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2015		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2016		-o -name '*.asn1.[ch]' \
2017		-o -name '*.symtypes' -o -name 'modules.order' \
2018		-o -name '*.c.[012]*.*' \
2019		-o -name '*.ll' \
2020		-o -name '*.gcno' \
2021		\) -type f -print \
2022		-o -name '.tmp_*' -print \
2023		| xargs rm -rf
2024
2025# Generate tags for editors
2026# ---------------------------------------------------------------------------
2027quiet_cmd_tags = GEN     $@
2028      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2029
2030tags TAGS cscope gtags: FORCE
2031	$(call cmd,tags)
2032
2033# Generate rust-project.json (a file that describes the structure of non-Cargo
2034# Rust projects) for rust-analyzer (an implementation of the Language Server
2035# Protocol).
2036PHONY += rust-analyzer
2037rust-analyzer:
2038	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
2039ifdef KBUILD_EXTMOD
2040# FIXME: external modules must not descend into a sub-directory of the kernel
2041	$(Q)$(MAKE) $(build)=$(objtree)/rust src=$(srctree)/rust $@
2042else
2043	$(Q)$(MAKE) $(build)=rust $@
2044endif
2045
2046# Script to generate missing namespace dependencies
2047# ---------------------------------------------------------------------------
2048
2049PHONY += nsdeps
2050nsdeps: export KBUILD_NSDEPS=1
2051nsdeps: modules
2052	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2053
2054# Clang Tooling
2055# ---------------------------------------------------------------------------
2056
2057quiet_cmd_gen_compile_commands = GEN     $@
2058      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2059
2060compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py \
2061	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2062	$(if $(CONFIG_MODULES), modules.order) FORCE
2063	$(call if_changed,gen_compile_commands)
2064
2065targets += compile_commands.json
2066
2067PHONY += clang-tidy clang-analyzer
2068
2069ifdef CONFIG_CC_IS_CLANG
2070quiet_cmd_clang_tools = CHECK   $<
2071      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2072
2073clang-tidy clang-analyzer: compile_commands.json
2074	$(call cmd,clang_tools)
2075else
2076clang-tidy clang-analyzer:
2077	@echo "$@ requires CC=clang" >&2
2078	@false
2079endif
2080
2081# Scripts to check various things for consistency
2082# ---------------------------------------------------------------------------
2083
2084PHONY += includecheck versioncheck coccicheck
2085
2086includecheck:
2087	find $(srctree)/* $(RCS_FIND_IGNORE) \
2088		-name '*.[hcS]' -type f -print | sort \
2089		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2090
2091versioncheck:
2092	find $(srctree)/* $(RCS_FIND_IGNORE) \
2093		-name '*.[hcS]' -type f -print | sort \
2094		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2095
2096coccicheck:
2097	$(Q)$(BASH) $(srctree)/scripts/$@
2098
2099PHONY += checkstack kernelrelease kernelversion image_name
2100
2101# UML needs a little special treatment here.  It wants to use the host
2102# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2103# else wants $(ARCH), including people doing cross-builds, which means
2104# that $(SUBARCH) doesn't work here.
2105ifeq ($(ARCH), um)
2106CHECKSTACK_ARCH := $(SUBARCH)
2107else
2108CHECKSTACK_ARCH := $(ARCH)
2109endif
2110MINSTACKSIZE	?= 100
2111checkstack:
2112	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2113	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2114
2115kernelrelease:
2116	@$(filechk_kernel.release)
2117
2118kernelversion:
2119	@echo $(KERNELVERSION)
2120
2121image_name:
2122	@echo $(KBUILD_IMAGE)
2123
2124PHONY += run-command
2125run-command:
2126	$(Q)$(KBUILD_RUN_COMMAND)
2127
2128quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2129      cmd_rmfiles = rm -rf $(rm-files)
2130
2131# read saved command lines for existing targets
2132existing-targets := $(wildcard $(sort $(targets)))
2133
2134-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2135
2136endif # config-build
2137endif # mixed-build
2138endif # need-sub-make
2139
2140PHONY += FORCE
2141FORCE:
2142
2143# Declare the contents of the PHONY variable as phony.  We keep that
2144# information in a variable so we can use it in if_changed and friends.
2145.PHONY: $(PHONY)
2146