xref: /linux/Makefile (revision c8bfe3fad4f86a029da7157bae9699c816f0c309)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 8
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Hurr durr I'ma ninja sloth
7
8# *DOCUMENTATION*
9# To see a list of typical targets execute "make help"
10# More info can be located in ./README
11# Comments in this file are targeted only to the developer, do not
12# expect to learn how to build the kernel reading this file.
13
14ifeq ($(filter undefine,$(.FEATURES)),)
15$(error GNU Make >= 3.82 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))
42export abs_srctree := $(realpath $(dir $(this-makefile)))
43export abs_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, $(KBUILD_VERBOSE)),)
90  quiet =
91  Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
97
98ifeq ($(filter 3.%,$(MAKE_VERSION)),)
99short-opts := $(firstword -$(MAKEFLAGS))
100else
101short-opts := $(filter-out --%,$(MAKEFLAGS))
102endif
103
104ifneq ($(findstring s,$(short-opts)),)
105quiet=silent_
106override KBUILD_VERBOSE :=
107endif
108
109export quiet Q KBUILD_VERBOSE
110
111# Call a source code checker (by default, "sparse") as part of the
112# C compilation.
113#
114# Use 'make C=1' to enable checking of only re-compiled files.
115# Use 'make C=2' to enable checking of *all* source files, regardless
116# of whether they are re-compiled or not.
117#
118# See the file "Documentation/dev-tools/sparse.rst" for more details,
119# including where to get the "sparse" utility.
120
121ifeq ("$(origin C)", "command line")
122  KBUILD_CHECKSRC = $(C)
123endif
124ifndef KBUILD_CHECKSRC
125  KBUILD_CHECKSRC = 0
126endif
127
128export KBUILD_CHECKSRC
129
130# Enable "clippy" (a linter) as part of the Rust compilation.
131#
132# Use 'make CLIPPY=1' to enable it.
133ifeq ("$(origin CLIPPY)", "command line")
134  KBUILD_CLIPPY := $(CLIPPY)
135endif
136
137export KBUILD_CLIPPY
138
139# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
140# directory of external module to build. Setting M= takes precedence.
141ifeq ("$(origin M)", "command line")
142  KBUILD_EXTMOD := $(M)
143endif
144
145$(if $(word 2, $(KBUILD_EXTMOD)), \
146	$(error building multiple external modules is not supported))
147
148$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
149	$(error module directory path cannot contain '$x')))
150
151# Remove trailing slashes
152ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
153KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
154endif
155
156export KBUILD_EXTMOD
157
158# backward compatibility
159KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
160
161ifeq ("$(origin W)", "command line")
162  KBUILD_EXTRA_WARN := $(W)
163endif
164
165export KBUILD_EXTRA_WARN
166
167# Kbuild will save output files in the current working directory.
168# This does not need to match to the root of the kernel source tree.
169#
170# For example, you can do this:
171#
172#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
173#
174# If you want to save output files in a different location, there are
175# two syntaxes to specify it.
176#
177# 1) O=
178# Use "make O=dir/to/store/output/files/"
179#
180# 2) Set KBUILD_OUTPUT
181# Set the environment variable KBUILD_OUTPUT to point to the output directory.
182# export KBUILD_OUTPUT=dir/to/store/output/files/; make
183#
184# The O= assignment takes precedence over the KBUILD_OUTPUT environment
185# variable.
186
187# Do we want to change the working directory?
188ifeq ("$(origin O)", "command line")
189  KBUILD_OUTPUT := $(O)
190endif
191
192ifneq ($(KBUILD_OUTPUT),)
193# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
194$(shell mkdir -p "$(KBUILD_OUTPUT)")
195# $(realpath ...) resolves symlinks
196abs_objtree := $(realpath $(KBUILD_OUTPUT))
197$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)"))
198endif # ifneq ($(KBUILD_OUTPUT),)
199
200ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
201$(error source directory cannot contain spaces or colons)
202endif
203
204ifneq ($(filter 3.%,$(MAKE_VERSION)),)
205# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
206# We need to invoke sub-make to avoid implicit rules in the top Makefile.
207need-sub-make := 1
208# Cancel implicit rules for this Makefile.
209$(this-makefile): ;
210endif
211
212export sub_make_done := 1
213
214endif # sub_make_done
215
216ifeq ($(abs_objtree),$(CURDIR))
217# Suppress "Entering directory ..." if we are at the final work directory.
218no-print-directory := --no-print-directory
219else
220# Recursion to show "Entering directory ..."
221need-sub-make := 1
222endif
223
224ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
225# If --no-print-directory is unset, recurse once again to set it.
226# You may end up recursing into __sub-make twice. This is needed due to the
227# behavior change in GNU Make 4.4.1.
228need-sub-make := 1
229endif
230
231ifeq ($(need-sub-make),1)
232
233PHONY += $(MAKECMDGOALS) __sub-make
234
235$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
236	@:
237
238# Invoke a second make in the output directory, passing relevant variables
239__sub-make:
240	$(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
241	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
242
243else # need-sub-make
244
245# We process the rest of the Makefile if this is the final invocation of make
246
247ifeq ($(abs_srctree),$(abs_objtree))
248        # building in the source tree
249        srctree := .
250	building_out_of_srctree :=
251else
252        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
253                # building in a subdirectory of the source tree
254                srctree := ..
255        else
256                srctree := $(abs_srctree)
257        endif
258	building_out_of_srctree := 1
259endif
260
261ifneq ($(KBUILD_ABS_SRCTREE),)
262srctree := $(abs_srctree)
263endif
264
265objtree		:= .
266VPATH		:= $(srctree)
267
268export building_out_of_srctree srctree objtree VPATH
269
270# To make sure we do not include .config for any of the *config targets
271# catch them early, and hand them over to scripts/kconfig/Makefile
272# It is allowed to specify more targets when calling make, including
273# mixing *config targets and build targets.
274# For example 'make oldconfig all'.
275# Detect when mixed targets is specified, and make a second invocation
276# of make so .config is not included in this case either (for *config).
277
278version_h := include/generated/uapi/linux/version.h
279
280clean-targets := %clean mrproper cleandocs
281no-dot-config-targets := $(clean-targets) \
282			 cscope gtags TAGS tags help% %docs check% coccicheck \
283			 $(version_h) headers headers_% archheaders archscripts \
284			 %asm-generic kernelversion %src-pkg dt_binding_check \
285			 outputmakefile rustavailable rustfmt rustfmtcheck
286no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
287			  image_name
288single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
289
290config-build	:=
291mixed-build	:=
292need-config	:= 1
293may-sync-config	:= 1
294single-build	:=
295
296ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
297    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
298		need-config :=
299    endif
300endif
301
302ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
303    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
304		may-sync-config :=
305    endif
306endif
307
308need-compiler := $(may-sync-config)
309
310ifneq ($(KBUILD_EXTMOD),)
311	may-sync-config :=
312endif
313
314ifeq ($(KBUILD_EXTMOD),)
315        ifneq ($(filter %config,$(MAKECMDGOALS)),)
316		config-build := 1
317                ifneq ($(words $(MAKECMDGOALS)),1)
318			mixed-build := 1
319                endif
320        endif
321endif
322
323# We cannot build single targets and the others at the same time
324ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
325	single-build := 1
326    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
327		mixed-build := 1
328    endif
329endif
330
331# For "make -j clean all", "make -j mrproper defconfig all", etc.
332ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
333        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
334		mixed-build := 1
335        endif
336endif
337
338# install and modules_install need also be processed one by one
339ifneq ($(filter install,$(MAKECMDGOALS)),)
340        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
341		mixed-build := 1
342        endif
343endif
344
345ifdef mixed-build
346# ===========================================================================
347# We're called with mixed targets (*config and build targets).
348# Handle them one by one.
349
350PHONY += $(MAKECMDGOALS) __build_one_by_one
351
352$(MAKECMDGOALS): __build_one_by_one
353	@:
354
355__build_one_by_one:
356	$(Q)set -e; \
357	for i in $(MAKECMDGOALS); do \
358		$(MAKE) -f $(srctree)/Makefile $$i; \
359	done
360
361else # !mixed-build
362
363include $(srctree)/scripts/Kbuild.include
364
365# Read KERNELRELEASE from include/config/kernel.release (if it exists)
366KERNELRELEASE = $(call read-file, include/config/kernel.release)
367KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
368export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
369
370include $(srctree)/scripts/subarch.include
371
372# Cross compiling and selecting different set of gcc/bin-utils
373# ---------------------------------------------------------------------------
374#
375# When performing cross compilation for other architectures ARCH shall be set
376# to the target architecture. (See arch/* for the possibilities).
377# ARCH can be set during invocation of make:
378# make ARCH=arm64
379# Another way is to have ARCH set in the environment.
380# The default ARCH is the host where make is executed.
381
382# CROSS_COMPILE specify the prefix used for all executables used
383# during compilation. Only gcc and related bin-utils executables
384# are prefixed with $(CROSS_COMPILE).
385# CROSS_COMPILE can be set on the command line
386# make CROSS_COMPILE=aarch64-linux-gnu-
387# Alternatively CROSS_COMPILE can be set in the environment.
388# Default value for CROSS_COMPILE is not to prefix executables
389# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
390ARCH		?= $(SUBARCH)
391
392# Architecture as present in compile.h
393UTS_MACHINE 	:= $(ARCH)
394SRCARCH 	:= $(ARCH)
395
396# Additional ARCH settings for x86
397ifeq ($(ARCH),i386)
398        SRCARCH := x86
399endif
400ifeq ($(ARCH),x86_64)
401        SRCARCH := x86
402endif
403
404# Additional ARCH settings for sparc
405ifeq ($(ARCH),sparc32)
406       SRCARCH := sparc
407endif
408ifeq ($(ARCH),sparc64)
409       SRCARCH := sparc
410endif
411
412# Additional ARCH settings for parisc
413ifeq ($(ARCH),parisc64)
414       SRCARCH := parisc
415endif
416
417export cross_compiling :=
418ifneq ($(SRCARCH),$(SUBARCH))
419cross_compiling := 1
420endif
421
422KCONFIG_CONFIG	?= .config
423export KCONFIG_CONFIG
424
425# SHELL used by kbuild
426CONFIG_SHELL := sh
427
428HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
429HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
430HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
431
432ifneq ($(LLVM),)
433ifneq ($(filter %/,$(LLVM)),)
434LLVM_PREFIX := $(LLVM)
435else ifneq ($(filter -%,$(LLVM)),)
436LLVM_SUFFIX := $(LLVM)
437endif
438
439HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
440HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
441else
442HOSTCC	= gcc
443HOSTCXX	= g++
444endif
445HOSTRUSTC = rustc
446HOSTPKG_CONFIG	= pkg-config
447
448KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
449			 -O2 -fomit-frame-pointer -std=gnu11
450KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
451KBUILD_USERLDFLAGS := $(USERLDFLAGS)
452
453# These flags apply to all Rust code in the tree, including the kernel and
454# host programs.
455export rust_common_flags := --edition=2021 \
456			    -Zbinary_dep_depinfo=y \
457			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
458			    -Dunreachable_pub -Dnon_ascii_idents \
459			    -Wmissing_docs \
460			    -Drustdoc::missing_crate_level_docs \
461			    -Dclippy::correctness -Dclippy::style \
462			    -Dclippy::suspicious -Dclippy::complexity \
463			    -Dclippy::perf \
464			    -Dclippy::let_unit_value -Dclippy::mut_mut \
465			    -Dclippy::needless_bitwise_bool \
466			    -Dclippy::needless_continue \
467			    -Dclippy::no_mangle_with_rust_abi \
468			    -Wclippy::dbg_macro
469
470KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
471KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
472KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
473			-Zallow-features= $(HOSTRUSTFLAGS)
474KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
475KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
476
477# Make variables (CC, etc...)
478CPP		= $(CC) -E
479ifneq ($(LLVM),)
480CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
481LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
482AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
483NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
484OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
485OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
486READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
487STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
488else
489CC		= $(CROSS_COMPILE)gcc
490LD		= $(CROSS_COMPILE)ld
491AR		= $(CROSS_COMPILE)ar
492NM		= $(CROSS_COMPILE)nm
493OBJCOPY		= $(CROSS_COMPILE)objcopy
494OBJDUMP		= $(CROSS_COMPILE)objdump
495READELF		= $(CROSS_COMPILE)readelf
496STRIP		= $(CROSS_COMPILE)strip
497endif
498RUSTC		= rustc
499RUSTDOC		= rustdoc
500RUSTFMT		= rustfmt
501CLIPPY_DRIVER	= clippy-driver
502BINDGEN		= bindgen
503CARGO		= cargo
504PAHOLE		= pahole
505RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
506LEX		= flex
507YACC		= bison
508AWK		= awk
509INSTALLKERNEL  := installkernel
510PERL		= perl
511PYTHON3		= python3
512CHECK		= sparse
513BASH		= bash
514KGZIP		= gzip
515KBZIP2		= bzip2
516KLZOP		= lzop
517LZMA		= lzma
518LZ4		= lz4c
519XZ		= xz
520ZSTD		= zstd
521
522CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
523		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
524NOSTDINC_FLAGS :=
525CFLAGS_MODULE   =
526RUSTFLAGS_MODULE =
527AFLAGS_MODULE   =
528LDFLAGS_MODULE  =
529CFLAGS_KERNEL	=
530RUSTFLAGS_KERNEL =
531AFLAGS_KERNEL	=
532LDFLAGS_vmlinux =
533
534# Use USERINCLUDE when you must reference the UAPI directories only.
535USERINCLUDE    := \
536		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
537		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
538		-I$(srctree)/include/uapi \
539		-I$(objtree)/include/generated/uapi \
540                -include $(srctree)/include/linux/compiler-version.h \
541                -include $(srctree)/include/linux/kconfig.h
542
543# Use LINUXINCLUDE when you must reference the include/ directory.
544# Needed to be compatible with the O= option
545LINUXINCLUDE    := \
546		-I$(srctree)/arch/$(SRCARCH)/include \
547		-I$(objtree)/arch/$(SRCARCH)/include/generated \
548		$(if $(building_out_of_srctree),-I$(srctree)/include) \
549		-I$(objtree)/include \
550		$(USERINCLUDE)
551
552KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
553
554KBUILD_CFLAGS :=
555KBUILD_CFLAGS += -std=gnu11
556KBUILD_CFLAGS += -fshort-wchar
557KBUILD_CFLAGS += -funsigned-char
558KBUILD_CFLAGS += -fno-common
559KBUILD_CFLAGS += -fno-PIE
560KBUILD_CFLAGS += -fno-strict-aliasing
561
562KBUILD_CPPFLAGS := -D__KERNEL__
563KBUILD_RUSTFLAGS := $(rust_common_flags) \
564		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
565		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
566		    -Csymbol-mangling-version=v0 \
567		    -Crelocation-model=static \
568		    -Zfunction-sections=n \
569		    -Dclippy::float_arithmetic
570
571KBUILD_AFLAGS_KERNEL :=
572KBUILD_CFLAGS_KERNEL :=
573KBUILD_RUSTFLAGS_KERNEL :=
574KBUILD_AFLAGS_MODULE  := -DMODULE
575KBUILD_CFLAGS_MODULE  := -DMODULE
576KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
577KBUILD_LDFLAGS_MODULE :=
578KBUILD_LDFLAGS :=
579CLANG_FLAGS :=
580
581ifeq ($(KBUILD_CLIPPY),1)
582	RUSTC_OR_CLIPPY_QUIET := CLIPPY
583	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
584else
585	RUSTC_OR_CLIPPY_QUIET := RUSTC
586	RUSTC_OR_CLIPPY = $(RUSTC)
587endif
588
589ifdef RUST_LIB_SRC
590	export RUST_LIB_SRC
591endif
592
593# Allows the usage of unstable features in stable compilers.
594export RUSTC_BOOTSTRAP := 1
595
596export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
597export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
598export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
599export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
600export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
601export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
602export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
603export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
604
605export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
606export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
607export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
608export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
609export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
610export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
611
612# Files to ignore in find ... statements
613
614export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
615			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
616			  -prune -o
617
618# ===========================================================================
619# Rules shared between *config targets and build targets
620
621# Basic helpers built in scripts/basic/
622PHONY += scripts_basic
623scripts_basic:
624	$(Q)$(MAKE) $(build)=scripts/basic
625
626PHONY += outputmakefile
627ifdef building_out_of_srctree
628# Before starting out-of-tree build, make sure the source tree is clean.
629# outputmakefile generates a Makefile in the output directory, if using a
630# separate output directory. This allows convenient use of make in the
631# output directory.
632# At the same time when output Makefile generated, generate .gitignore to
633# ignore whole output directory
634
635quiet_cmd_makefile = GEN     Makefile
636      cmd_makefile = { \
637	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
638	echo "include $(srctree)/Makefile"; \
639	} > Makefile
640
641outputmakefile:
642	@if [ -f $(srctree)/.config -o \
643		 -d $(srctree)/include/config -o \
644		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
645		echo >&2 "***"; \
646		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
647		echo >&2 "*** in $(abs_srctree)";\
648		echo >&2 "***"; \
649		false; \
650	fi
651	$(Q)ln -fsn $(srctree) source
652	$(call cmd,makefile)
653	$(Q)test -e .gitignore || \
654	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
655endif
656
657# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
658# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
659# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
660# and from include/config/auto.conf.cmd to detect the compiler upgrade.
661CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
662
663ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
664include $(srctree)/scripts/Makefile.clang
665endif
666
667# Include this also for config targets because some architectures need
668# cc-cross-prefix to determine CROSS_COMPILE.
669ifdef need-compiler
670include $(srctree)/scripts/Makefile.compiler
671endif
672
673ifdef config-build
674# ===========================================================================
675# *config targets only - make sure prerequisites are updated, and descend
676# in scripts/kconfig to make the *config target
677
678# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
679# KBUILD_DEFCONFIG may point out an alternative default configuration
680# used for 'make defconfig'
681include $(srctree)/arch/$(SRCARCH)/Makefile
682export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
683
684config: outputmakefile scripts_basic FORCE
685	$(Q)$(MAKE) $(build)=scripts/kconfig $@
686
687%config: outputmakefile scripts_basic FORCE
688	$(Q)$(MAKE) $(build)=scripts/kconfig $@
689
690else #!config-build
691# ===========================================================================
692# Build targets only - this includes vmlinux, arch-specific targets, clean
693# targets and others. In general all targets except *config targets.
694
695# If building an external module we do not care about the all: rule
696# but instead __all depend on modules
697PHONY += all
698ifeq ($(KBUILD_EXTMOD),)
699__all: all
700else
701__all: modules
702endif
703
704targets :=
705
706# Decide whether to build built-in, modular, or both.
707# Normally, just do built-in.
708
709KBUILD_MODULES :=
710KBUILD_BUILTIN := 1
711
712# If we have only "make modules", don't compile built-in objects.
713ifeq ($(MAKECMDGOALS),modules)
714  KBUILD_BUILTIN :=
715endif
716
717# If we have "make <whatever> modules", compile modules
718# in addition to whatever we do anyway.
719# Just "make" or "make all" shall build modules as well
720
721ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
722  KBUILD_MODULES := 1
723endif
724
725ifeq ($(MAKECMDGOALS),)
726  KBUILD_MODULES := 1
727endif
728
729export KBUILD_MODULES KBUILD_BUILTIN
730
731ifdef need-config
732include include/config/auto.conf
733endif
734
735ifeq ($(KBUILD_EXTMOD),)
736# Objects we will link into vmlinux / subdirs we need to visit
737core-y		:=
738drivers-y	:=
739libs-y		:= lib/
740endif # KBUILD_EXTMOD
741
742# The all: target is the default when no target is given on the
743# command line.
744# This allow a user to issue only 'make' to build a kernel including modules
745# Defaults to vmlinux, but the arch makefile usually adds further targets
746all: vmlinux
747
748CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
749ifdef CONFIG_CC_IS_GCC
750CFLAGS_GCOV	+= -fno-tree-loop-im
751endif
752export CFLAGS_GCOV
753
754# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
755ifdef CONFIG_FUNCTION_TRACER
756  CC_FLAGS_FTRACE := -pg
757endif
758
759include $(srctree)/arch/$(SRCARCH)/Makefile
760
761ifdef need-config
762ifdef may-sync-config
763# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
764# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
765# because some architectures define CROSS_COMPILE there.
766include include/config/auto.conf.cmd
767
768$(KCONFIG_CONFIG):
769	@echo >&2 '***'
770	@echo >&2 '*** Configuration file "$@" not found!'
771	@echo >&2 '***'
772	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
773	@echo >&2 '*** "make menuconfig" or "make xconfig").'
774	@echo >&2 '***'
775	@/bin/false
776
777# The actual configuration files used during the build are stored in
778# include/generated/ and include/config/. Update them if .config is newer than
779# include/config/auto.conf (which mirrors .config).
780#
781# This exploits the 'multi-target pattern rule' trick.
782# The syncconfig should be executed only once to make all the targets.
783# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
784#
785# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
786# so you cannot notice that Kconfig is waiting for the user input.
787%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
788	$(Q)$(kecho) "  SYNC    $@"
789	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
790else # !may-sync-config
791# External modules and some install targets need include/generated/autoconf.h
792# and include/config/auto.conf but do not care if they are up-to-date.
793# Use auto.conf to trigger the test
794PHONY += include/config/auto.conf
795
796include/config/auto.conf:
797	@test -e include/generated/autoconf.h -a -e $@ || (		\
798	echo >&2;							\
799	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
800	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
801	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
802	echo >&2 ;							\
803	/bin/false)
804
805endif # may-sync-config
806endif # need-config
807
808KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
809
810ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
811KBUILD_CFLAGS += -O2
812KBUILD_RUSTFLAGS += -Copt-level=2
813else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
814KBUILD_CFLAGS += -Os
815KBUILD_RUSTFLAGS += -Copt-level=s
816endif
817
818# Always set `debug-assertions` and `overflow-checks` because their default
819# depends on `opt-level` and `debug-assertions`, respectively.
820KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
821KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
822
823# Tell gcc to never replace conditional load with a non-conditional one
824ifdef CONFIG_CC_IS_GCC
825# gcc-10 renamed --param=allow-store-data-races=0 to
826# -fno-allow-store-data-races.
827KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
828KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
829endif
830
831ifdef CONFIG_READABLE_ASM
832# Disable optimizations that make assembler listings hard to read.
833# reorder blocks reorders the control in the function
834# ipa clone creates specialized cloned functions
835# partial inlining inlines only parts of functions
836KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
837endif
838
839stackp-flags-y                                    := -fno-stack-protector
840stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
841stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
842
843KBUILD_CFLAGS += $(stackp-flags-y)
844
845KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
846KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
847
848ifdef CONFIG_FRAME_POINTER
849KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
850KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
851else
852# Some targets (ARM with Thumb2, for example), can't be built with frame
853# pointers.  For those, we don't have FUNCTION_TRACER automatically
854# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
855# incompatible with -fomit-frame-pointer with current GCC, so we don't use
856# -fomit-frame-pointer with FUNCTION_TRACER.
857# In the Rust target specification, "frame-pointer" is set explicitly
858# to "may-omit".
859ifndef CONFIG_FUNCTION_TRACER
860KBUILD_CFLAGS	+= -fomit-frame-pointer
861endif
862endif
863
864# Initialize all stack variables with a 0xAA pattern.
865ifdef CONFIG_INIT_STACK_ALL_PATTERN
866KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
867endif
868
869# Initialize all stack variables with a zero value.
870ifdef CONFIG_INIT_STACK_ALL_ZERO
871KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
872ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
873# https://github.com/llvm/llvm-project/issues/44842
874CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
875export CC_AUTO_VAR_INIT_ZERO_ENABLER
876KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
877endif
878endif
879
880# While VLAs have been removed, GCC produces unreachable stack probes
881# for the randomize_kstack_offset feature. Disable it for all compilers.
882KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
883
884# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
885ifdef CONFIG_ZERO_CALL_USED_REGS
886KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
887endif
888
889ifdef CONFIG_FUNCTION_TRACER
890ifdef CONFIG_FTRACE_MCOUNT_USE_CC
891  CC_FLAGS_FTRACE	+= -mrecord-mcount
892  ifdef CONFIG_HAVE_NOP_MCOUNT
893    ifeq ($(call cc-option-yn, -mnop-mcount),y)
894      CC_FLAGS_FTRACE	+= -mnop-mcount
895      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
896    endif
897  endif
898endif
899ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
900  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
901    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
902  endif
903endif
904ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
905  ifdef CONFIG_HAVE_C_RECORDMCOUNT
906    BUILD_C_RECORDMCOUNT := y
907    export BUILD_C_RECORDMCOUNT
908  endif
909endif
910ifdef CONFIG_HAVE_FENTRY
911  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
912  ifeq ($(call cc-option-yn, -mfentry),y)
913    CC_FLAGS_FTRACE	+= -mfentry
914    CC_FLAGS_USING	+= -DCC_USING_FENTRY
915  endif
916endif
917export CC_FLAGS_FTRACE
918KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
919KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
920endif
921
922# We trigger additional mismatches with less inlining
923ifdef CONFIG_DEBUG_SECTION_MISMATCH
924KBUILD_CFLAGS += -fno-inline-functions-called-once
925endif
926
927# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
928ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
929KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
930KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
931LDFLAGS_vmlinux += --gc-sections
932endif
933
934ifdef CONFIG_SHADOW_CALL_STACK
935ifndef CONFIG_DYNAMIC_SCS
936CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
937KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
938endif
939export CC_FLAGS_SCS
940endif
941
942ifdef CONFIG_LTO_CLANG
943ifdef CONFIG_LTO_CLANG_THIN
944CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
945KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
946else
947CC_FLAGS_LTO	:= -flto
948endif
949CC_FLAGS_LTO	+= -fvisibility=hidden
950
951# Limit inlining across translation units to reduce binary size
952KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
953endif
954
955ifdef CONFIG_LTO
956KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
957KBUILD_AFLAGS	+= -fno-lto
958export CC_FLAGS_LTO
959endif
960
961ifdef CONFIG_CFI_CLANG
962CC_FLAGS_CFI	:= -fsanitize=kcfi
963KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
964export CC_FLAGS_CFI
965endif
966
967ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
968KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
969endif
970
971# arch Makefile may override CC so keep this after arch Makefile is included
972NOSTDINC_FLAGS += -nostdinc
973
974# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
975# the kernel uses only C99 flexible arrays for dynamically sized trailing
976# arrays. Enforce this for everything that may examine structure sizes and
977# perform bounds checking.
978KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
979
980#Currently, disable -Wstringop-overflow for GCC 11, globally.
981KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
982KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
983
984# disable invalid "can't wrap" optimizations for signed / pointers
985KBUILD_CFLAGS	+= -fno-strict-overflow
986
987# Make sure -fstack-check isn't enabled (like gentoo apparently did)
988KBUILD_CFLAGS  += -fno-stack-check
989
990# conserve stack if available
991ifdef CONFIG_CC_IS_GCC
992KBUILD_CFLAGS   += -fconserve-stack
993endif
994
995# change __FILE__ to the relative path from the srctree
996KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
997
998# include additional Makefiles when needed
999include-y			:= scripts/Makefile.extrawarn
1000include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1001include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1002include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1003include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1004include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1005include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1006include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1007include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1008include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1009
1010include $(addprefix $(srctree)/, $(include-y))
1011
1012# scripts/Makefile.gcc-plugins is intentionally included last.
1013# Do not add $(call cc-option,...) below this line. When you build the kernel
1014# from the clean source tree, the GCC plugins do not exist at this point.
1015
1016# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1017KBUILD_CPPFLAGS += $(KCPPFLAGS)
1018KBUILD_AFLAGS   += $(KAFLAGS)
1019KBUILD_CFLAGS   += $(KCFLAGS)
1020KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1021
1022KBUILD_LDFLAGS_MODULE += --build-id=sha1
1023LDFLAGS_vmlinux += --build-id=sha1
1024
1025KBUILD_LDFLAGS	+= -z noexecstack
1026ifeq ($(CONFIG_LD_IS_BFD),y)
1027KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1028endif
1029
1030ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1031LDFLAGS_vmlinux	+= -X
1032endif
1033
1034ifeq ($(CONFIG_RELR),y)
1035# ld.lld before 15 did not support -z pack-relative-relocs.
1036LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1037endif
1038
1039# We never want expected sections to be placed heuristically by the
1040# linker. All sections should be explicitly named in the linker script.
1041ifdef CONFIG_LD_ORPHAN_WARN
1042LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1043endif
1044
1045# Align the bit size of userspace programs with the kernel
1046KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1047KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1048
1049# make the checker run with the right architecture
1050CHECKFLAGS += --arch=$(ARCH)
1051
1052# insure the checker run with the right endianness
1053CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1054
1055# the checker needs the correct machine size
1056CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1057
1058# Default kernel image to build when no specific target is given.
1059# KBUILD_IMAGE may be overruled on the command line or
1060# set in the environment
1061# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1062# this default value
1063export KBUILD_IMAGE ?= vmlinux
1064
1065#
1066# INSTALL_PATH specifies where to place the updated kernel and system map
1067# images. Default is /boot, but you can set it to other values
1068export	INSTALL_PATH ?= /boot
1069
1070#
1071# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1072# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1073# an argument if needed. Otherwise it defaults to the kernel install path
1074#
1075export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1076
1077#
1078# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1079# relocations required by build roots.  This is not defined in the
1080# makefile but the argument can be passed to make if needed.
1081#
1082
1083MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1084export MODLIB
1085
1086PHONY += prepare0
1087
1088export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1089export MODORDER := $(extmod_prefix)modules.order
1090export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1091
1092ifeq ($(KBUILD_EXTMOD),)
1093
1094build-dir	:= .
1095clean-dirs	:= $(sort . Documentation \
1096		     $(patsubst %/,%,$(filter %/, $(core-) \
1097			$(drivers-) $(libs-))))
1098
1099export ARCH_CORE	:= $(core-y)
1100export ARCH_LIB		:= $(filter %/, $(libs-y))
1101export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1102# Externally visible symbols (used by link-vmlinux.sh)
1103
1104KBUILD_VMLINUX_OBJS := ./built-in.a
1105ifdef CONFIG_MODULES
1106KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1107KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1108else
1109KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1110endif
1111
1112export KBUILD_VMLINUX_LIBS
1113export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1114
1115ifdef CONFIG_TRIM_UNUSED_KSYMS
1116# For the kernel to actually contain only the needed exported symbols,
1117# we have to build modules as well to determine what those symbols are.
1118KBUILD_MODULES := 1
1119endif
1120
1121# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1122quiet_cmd_ar_vmlinux.a = AR      $@
1123      cmd_ar_vmlinux.a = \
1124	rm -f $@; \
1125	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1126	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1127
1128targets += vmlinux.a
1129vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1130	$(call if_changed,ar_vmlinux.a)
1131
1132PHONY += vmlinux_o
1133vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1134	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1135
1136vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1137	@:
1138
1139PHONY += vmlinux
1140# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1141# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1142# unrelated; the decompressors just happen to have the same base name,
1143# arch/*/boot/compressed/vmlinux.
1144# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1145#
1146# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1147#   https://savannah.gnu.org/bugs/?61463
1148# For Make > 4.4, the following simple code will work:
1149#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1150vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1151vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1152vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1153	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1154
1155# The actual objects are generated when descending,
1156# make sure no implicit rule kicks in
1157$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1158
1159ifeq ($(origin KERNELRELEASE),file)
1160filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1161else
1162filechk_kernel.release = echo $(KERNELRELEASE)
1163endif
1164
1165# Store (new) KERNELRELEASE string in include/config/kernel.release
1166include/config/kernel.release: FORCE
1167	$(call filechk,kernel.release)
1168
1169# Additional helpers built in scripts/
1170# Carefully list dependencies so we do not try to build scripts twice
1171# in parallel
1172PHONY += scripts
1173scripts: scripts_basic scripts_dtc
1174	$(Q)$(MAKE) $(build)=$(@)
1175
1176# Things we need to do before we recursively start building the kernel
1177# or the modules are listed in "prepare".
1178# A multi level approach is used. prepareN is processed before prepareN-1.
1179# archprepare is used in arch Makefiles and when processed asm symlink,
1180# version.h and scripts_basic is processed / created.
1181
1182PHONY += prepare archprepare
1183
1184archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1185	asm-generic $(version_h) include/generated/utsrelease.h \
1186	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1187
1188prepare0: archprepare
1189	$(Q)$(MAKE) $(build)=scripts/mod
1190	$(Q)$(MAKE) $(build)=. prepare
1191
1192# All the preparing..
1193prepare: prepare0
1194ifdef CONFIG_RUST
1195	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1196	$(Q)$(MAKE) $(build)=rust
1197endif
1198
1199PHONY += remove-stale-files
1200remove-stale-files:
1201	$(Q)$(srctree)/scripts/remove-stale-files
1202
1203# Support for using generic headers in asm-generic
1204asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1205
1206PHONY += asm-generic uapi-asm-generic
1207asm-generic: uapi-asm-generic
1208	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1209	generic=include/asm-generic
1210uapi-asm-generic:
1211	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1212	generic=include/uapi/asm-generic
1213
1214# Generate some files
1215# ---------------------------------------------------------------------------
1216
1217# KERNELRELEASE can change from a few different places, meaning version.h
1218# needs to be updated, so this check is forced on all builds
1219
1220uts_len := 64
1221define filechk_utsrelease.h
1222	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1223	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1224	  exit 1;                                                         \
1225	fi;                                                               \
1226	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1227endef
1228
1229define filechk_version.h
1230	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1231		echo \#define LINUX_VERSION_CODE $(shell                 \
1232		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1233	else                                                             \
1234		echo \#define LINUX_VERSION_CODE $(shell                 \
1235		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1236	fi;                                                              \
1237	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1238	((c) > 255 ? 255 : (c)))';                                       \
1239	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1240	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1241	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1242endef
1243
1244$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1245$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1246$(version_h): FORCE
1247	$(call filechk,version.h)
1248
1249include/generated/utsrelease.h: include/config/kernel.release FORCE
1250	$(call filechk,utsrelease.h)
1251
1252filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1253	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1254
1255include/generated/compile.h: FORCE
1256	$(call filechk,compile.h)
1257
1258PHONY += headerdep
1259headerdep:
1260	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1261	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1262
1263# ---------------------------------------------------------------------------
1264# Kernel headers
1265
1266#Default location for installed headers
1267export INSTALL_HDR_PATH = $(objtree)/usr
1268
1269quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1270      cmd_headers_install = \
1271	mkdir -p $(INSTALL_HDR_PATH); \
1272	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1273	usr/include $(INSTALL_HDR_PATH)
1274
1275PHONY += headers_install
1276headers_install: headers
1277	$(call cmd,headers_install)
1278
1279PHONY += archheaders archscripts
1280
1281hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1282
1283PHONY += headers
1284headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1285	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1286	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1287	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1288
1289ifdef CONFIG_HEADERS_INSTALL
1290prepare: headers
1291endif
1292
1293PHONY += scripts_unifdef
1294scripts_unifdef: scripts_basic
1295	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1296
1297# ---------------------------------------------------------------------------
1298# Install
1299
1300# Many distributions have the custom install script, /sbin/installkernel.
1301# If DKMS is installed, 'make install' will eventually recurse back
1302# to this Makefile to build and install external modules.
1303# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1304
1305quiet_cmd_install = INSTALL $(INSTALL_PATH)
1306      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1307
1308# ---------------------------------------------------------------------------
1309# vDSO install
1310
1311PHONY += vdso_install
1312vdso_install: export INSTALL_FILES = $(vdso-install-y)
1313vdso_install:
1314	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1315
1316# ---------------------------------------------------------------------------
1317# Tools
1318
1319ifdef CONFIG_OBJTOOL
1320prepare: tools/objtool
1321endif
1322
1323ifdef CONFIG_BPF
1324ifdef CONFIG_DEBUG_INFO_BTF
1325prepare: tools/bpf/resolve_btfids
1326endif
1327endif
1328
1329PHONY += resolve_btfids_clean
1330
1331resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1332
1333# tools/bpf/resolve_btfids directory might not exist
1334# in output directory, skip its clean in that case
1335resolve_btfids_clean:
1336ifneq ($(wildcard $(resolve_btfids_O)),)
1337	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1338endif
1339
1340# Clear a bunch of variables before executing the submake
1341ifeq ($(quiet),silent_)
1342tools_silent=s
1343endif
1344
1345tools/: FORCE
1346	$(Q)mkdir -p $(objtree)/tools
1347	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1348
1349tools/%: FORCE
1350	$(Q)mkdir -p $(objtree)/tools
1351	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1352
1353# ---------------------------------------------------------------------------
1354# Kernel selftest
1355
1356PHONY += kselftest
1357kselftest: headers
1358	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1359
1360kselftest-%: headers FORCE
1361	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1362
1363PHONY += kselftest-merge
1364kselftest-merge:
1365	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1366	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1367		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1368	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1369
1370# ---------------------------------------------------------------------------
1371# Devicetree files
1372
1373ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1374dtstree := arch/$(SRCARCH)/boot/dts
1375endif
1376
1377ifneq ($(dtstree),)
1378
1379%.dtb: dtbs_prepare
1380	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1381
1382%.dtbo: dtbs_prepare
1383	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1384
1385PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1386dtbs: dtbs_prepare
1387	$(Q)$(MAKE) $(build)=$(dtstree)
1388
1389# include/config/kernel.release is actually needed when installing DTBs because
1390# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1391# dtbs_install depend on it as dtbs_install may run as root.
1392dtbs_prepare: include/config/kernel.release scripts_dtc
1393
1394ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1395export CHECK_DTBS=y
1396endif
1397
1398ifneq ($(CHECK_DTBS),)
1399dtbs_prepare: dt_binding_check
1400endif
1401
1402dtbs_check: dtbs
1403
1404dtbs_install:
1405	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1406
1407ifdef CONFIG_OF_EARLY_FLATTREE
1408all: dtbs
1409endif
1410
1411endif
1412
1413PHONY += scripts_dtc
1414scripts_dtc: scripts_basic
1415	$(Q)$(MAKE) $(build)=scripts/dtc
1416
1417ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1418export CHECK_DT_BINDING=y
1419endif
1420
1421PHONY += dt_binding_check
1422dt_binding_check: scripts_dtc
1423	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1424
1425PHONY += dt_compatible_check
1426dt_compatible_check: dt_binding_check
1427	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1428
1429# ---------------------------------------------------------------------------
1430# Modules
1431
1432ifdef CONFIG_MODULES
1433
1434# By default, build modules as well
1435
1436all: modules
1437
1438# When we're building modules with modversions, we need to consider
1439# the built-in objects during the descend as well, in order to
1440# make sure the checksums are up to date before we record them.
1441ifdef CONFIG_MODVERSIONS
1442  KBUILD_BUILTIN := 1
1443endif
1444
1445# Build modules
1446#
1447
1448# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1449# is an exception.
1450ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1451KBUILD_BUILTIN := 1
1452modules: vmlinux
1453endif
1454
1455modules: modules_prepare
1456
1457# Target to prepare building external modules
1458modules_prepare: prepare
1459	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1460
1461endif # CONFIG_MODULES
1462
1463###
1464# Cleaning is done on three levels.
1465# make clean     Delete most generated files
1466#                Leave enough to build external modules
1467# make mrproper  Delete the current configuration, and all generated files
1468# make distclean Remove editor backup files, patch leftover files and the like
1469
1470# Directories & files removed with 'make clean'
1471CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1472	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1473	       compile_commands.json .thinlto-cache rust/test \
1474	       rust-project.json .vmlinux.objs .vmlinux.export.c
1475
1476# Directories & files removed with 'make mrproper'
1477MRPROPER_FILES += include/config include/generated          \
1478		  arch/$(SRCARCH)/include/generated .objdiff \
1479		  debian snap tar-install \
1480		  .config .config.old .version \
1481		  Module.symvers \
1482		  certs/signing_key.pem \
1483		  certs/x509.genkey \
1484		  vmlinux-gdb.py \
1485		  rpmbuild \
1486		  rust/libmacros.so
1487
1488# clean - Delete most, but leave enough to build external modules
1489#
1490clean: rm-files := $(CLEAN_FILES)
1491
1492PHONY += archclean vmlinuxclean
1493
1494vmlinuxclean:
1495	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1496	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1497
1498clean: archclean vmlinuxclean resolve_btfids_clean
1499
1500# mrproper - Delete all generated files, including .config
1501#
1502mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1503mrproper-dirs      := $(addprefix _mrproper_,scripts)
1504
1505PHONY += $(mrproper-dirs) mrproper
1506$(mrproper-dirs):
1507	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1508
1509mrproper: clean $(mrproper-dirs)
1510	$(call cmd,rmfiles)
1511	@find . $(RCS_FIND_IGNORE) \
1512		\( -name '*.rmeta' \) \
1513		-type f -print | xargs rm -f
1514
1515# distclean
1516#
1517PHONY += distclean
1518
1519distclean: mrproper
1520	@find . $(RCS_FIND_IGNORE) \
1521		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1522		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1523		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1524		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1525		-type f -print | xargs rm -f
1526
1527
1528# Packaging of the kernel to various formats
1529# ---------------------------------------------------------------------------
1530
1531%src-pkg: FORCE
1532	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1533%pkg: include/config/kernel.release FORCE
1534	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1535
1536# Brief documentation of the typical targets used
1537# ---------------------------------------------------------------------------
1538
1539boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1540boards := $(sort $(notdir $(boards)))
1541board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1542board-dirs := $(sort $(notdir $(board-dirs:/=)))
1543
1544PHONY += help
1545help:
1546	@echo  'Cleaning targets:'
1547	@echo  '  clean		  - Remove most generated files but keep the config and'
1548	@echo  '                    enough build support to build external modules'
1549	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1550	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1551	@echo  ''
1552	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1553	@echo  ''
1554	@echo  'Other generic targets:'
1555	@echo  '  all		  - Build all targets marked with [*]'
1556	@echo  '* vmlinux	  - Build the bare kernel'
1557	@echo  '* modules	  - Build all modules'
1558	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1559	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1560	@echo  '  dir/            - Build all files in dir and below'
1561	@echo  '  dir/file.[ois]  - Build specified target only'
1562	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1563	@echo  '                    (requires compiler support for LLVM assembly generation)'
1564	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1565	@echo  '                    (requires a recent binutils and recent build (System.map))'
1566	@echo  '  dir/file.ko     - Build module including final link'
1567	@echo  '  modules_prepare - Set up for building external modules'
1568	@echo  '  tags/TAGS	  - Generate tags file for editors'
1569	@echo  '  cscope	  - Generate cscope index'
1570	@echo  '  gtags           - Generate GNU GLOBAL index'
1571	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1572	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1573	@echo  '  image_name	  - Output the image name (use with make -s)'
1574	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1575	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1576	 echo  ''
1577	@echo  'Static analysers:'
1578	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1579	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1580	@echo  '  versioncheck    - Sanity check on version.h usage'
1581	@echo  '  includecheck    - Check for duplicate included header files'
1582	@echo  '  export_report   - List the usages of all exported symbols'
1583	@echo  '  headerdep       - Detect inclusion cycles in headers'
1584	@echo  '  coccicheck      - Check with Coccinelle'
1585	@echo  '  clang-analyzer  - Check with clang static analyzer'
1586	@echo  '  clang-tidy      - Check with clang-tidy'
1587	@echo  ''
1588	@echo  'Tools:'
1589	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1590	@echo  ''
1591	@echo  'Kernel selftest:'
1592	@echo  '  kselftest         - Build and run kernel selftest'
1593	@echo  '                      Build, install, and boot kernel before'
1594	@echo  '                      running kselftest on it'
1595	@echo  '                      Run as root for full coverage'
1596	@echo  '  kselftest-all     - Build kernel selftest'
1597	@echo  '  kselftest-install - Build and install kernel selftest'
1598	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1599	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1600	@echo  '		      kselftest to existing .config.'
1601	@echo  ''
1602	@echo  'Rust targets:'
1603	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1604	@echo  '		    available and, if not, explains why.'
1605	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1606	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1607	@echo  '		    is formatted, printing a diff otherwise.'
1608	@echo  '  rustdoc	  - Generate Rust documentation'
1609	@echo  '		    (requires kernel .config)'
1610	@echo  '  rusttest        - Runs the Rust tests'
1611	@echo  '                    (requires kernel .config; downloads external repos)'
1612	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1613	@echo  '		    (requires kernel .config)'
1614	@echo  '  dir/file.[os]   - Build specified target only'
1615	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1616	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1617	@echo  '                    The output is not intended to be compilable.'
1618	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1619	@echo  ''
1620	@$(if $(dtstree), \
1621		echo 'Devicetree:'; \
1622		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1623		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1624		echo '  dt_binding_check - Validate device tree binding documents'; \
1625		echo '  dtbs_check       - Validate device tree source files';\
1626		echo '')
1627
1628	@echo 'Userspace tools targets:'
1629	@echo '  use "make tools/help"'
1630	@echo '  or  "cd tools; make help"'
1631	@echo  ''
1632	@echo  'Kernel packaging:'
1633	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1634	@echo  ''
1635	@echo  'Documentation targets:'
1636	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1637	@echo  ''
1638	@echo  'Architecture-specific targets ($(SRCARCH)):'
1639	@$(or $(archhelp),\
1640		echo '  No architecture-specific help defined for $(SRCARCH)')
1641	@echo  ''
1642	@$(if $(boards), \
1643		$(foreach b, $(boards), \
1644		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1645		echo '')
1646	@$(if $(board-dirs), \
1647		$(foreach b, $(board-dirs), \
1648		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1649		printf "  %-16s - Show all of the above\\n" help-boards; \
1650		echo '')
1651
1652	@echo  '  make V=n   [targets] 1: verbose build'
1653	@echo  '                       2: give reason for rebuild of target'
1654	@echo  '                       V=1 and V=2 can be combined with V=12'
1655	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1656	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1657	@echo  '                       (sparse by default)'
1658	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1659	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1660	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1661	@echo  '		1: warnings which may be relevant and do not occur too often'
1662	@echo  '		2: warnings which occur quite often but may still be relevant'
1663	@echo  '		3: more obscure warnings, can most likely be ignored'
1664	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1665	@echo  '		e: warnings are being treated as errors'
1666	@echo  '		Multiple levels can be combined with W=12 or W=123'
1667	@$(if $(dtstree), \
1668		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1669		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1670		)
1671	@echo  ''
1672	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1673	@echo  'For further info see the ./README file'
1674
1675
1676help-board-dirs := $(addprefix help-,$(board-dirs))
1677
1678help-boards: $(help-board-dirs)
1679
1680boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1681
1682$(help-board-dirs): help-%:
1683	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1684	@$(if $(boards-per-dir), \
1685		$(foreach b, $(boards-per-dir), \
1686		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1687		echo '')
1688
1689
1690# Documentation targets
1691# ---------------------------------------------------------------------------
1692DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1693	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1694PHONY += $(DOC_TARGETS)
1695$(DOC_TARGETS):
1696	$(Q)$(MAKE) $(build)=Documentation $@
1697
1698
1699# Rust targets
1700# ---------------------------------------------------------------------------
1701
1702# "Is Rust available?" target
1703PHONY += rustavailable
1704rustavailable:
1705	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1706
1707# Documentation target
1708#
1709# Using the singular to avoid running afoul of `no-dot-config-targets`.
1710PHONY += rustdoc
1711rustdoc: prepare
1712	$(Q)$(MAKE) $(build)=rust $@
1713
1714# Testing target
1715PHONY += rusttest
1716rusttest: prepare
1717	$(Q)$(MAKE) $(build)=rust $@
1718
1719# Formatting targets
1720PHONY += rustfmt rustfmtcheck
1721
1722# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1723#
1724# We match using absolute paths since `find` does not resolve them
1725# when matching, which is a problem when e.g. `srctree` is `..`.
1726# We `grep` afterwards in order to remove the directory entry itself.
1727rustfmt:
1728	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1729		-o -path $(abs_srctree)/rust/alloc -prune \
1730		-o -path $(abs_objtree)/rust/test -prune \
1731		| grep -Fv $(abs_srctree)/rust/alloc \
1732		| grep -Fv $(abs_objtree)/rust/test \
1733		| grep -Fv generated \
1734		| xargs $(RUSTFMT) $(rustfmt_flags)
1735
1736rustfmtcheck: rustfmt_flags = --check
1737rustfmtcheck: rustfmt
1738
1739# Misc
1740# ---------------------------------------------------------------------------
1741
1742PHONY += misc-check
1743misc-check:
1744	$(Q)$(srctree)/scripts/misc-check
1745
1746all: misc-check
1747
1748PHONY += scripts_gdb
1749scripts_gdb: prepare0
1750	$(Q)$(MAKE) $(build)=scripts/gdb
1751	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1752
1753ifdef CONFIG_GDB_SCRIPTS
1754all: scripts_gdb
1755endif
1756
1757else # KBUILD_EXTMOD
1758
1759filechk_kernel.release = echo $(KERNELRELEASE)
1760
1761###
1762# External module support.
1763# When building external modules the kernel used as basis is considered
1764# read-only, and no consistency checks are made and the make
1765# system is not used on the basis kernel. If updates are required
1766# in the basis kernel ordinary make commands (without M=...) must be used.
1767
1768# We are always building only modules.
1769KBUILD_BUILTIN :=
1770KBUILD_MODULES := 1
1771
1772build-dir := $(KBUILD_EXTMOD)
1773
1774compile_commands.json: $(extmod_prefix)compile_commands.json
1775PHONY += compile_commands.json
1776
1777clean-dirs := $(KBUILD_EXTMOD)
1778clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1779	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1780
1781PHONY += prepare
1782# now expand this into a simple variable to reduce the cost of shell evaluations
1783prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1784prepare:
1785	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1786		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1787		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1788		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1789	fi
1790
1791PHONY += help
1792help:
1793	@echo  '  Building external modules.'
1794	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1795	@echo  ''
1796	@echo  '  modules         - default target, build the module(s)'
1797	@echo  '  modules_install - install the module'
1798	@echo  '  clean           - remove generated files in module directory only'
1799	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1800	@echo  ''
1801
1802ifndef CONFIG_MODULES
1803modules modules_install: __external_modules_error
1804__external_modules_error:
1805	@echo >&2 '***'
1806	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1807	@echo >&2 '*** You cannot build or install external modules.'
1808	@echo >&2 '***'
1809	@false
1810endif
1811
1812endif # KBUILD_EXTMOD
1813
1814# ---------------------------------------------------------------------------
1815# Modules
1816
1817PHONY += modules modules_install modules_sign modules_prepare
1818
1819modules_install:
1820	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1821	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1822
1823ifeq ($(CONFIG_MODULE_SIG),y)
1824# modules_sign is a subset of modules_install.
1825# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1826modules_sign: modules_install
1827	@:
1828else
1829modules_sign:
1830	@echo >&2 '***'
1831	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1832	@echo >&2 '***'
1833	@false
1834endif
1835
1836ifdef CONFIG_MODULES
1837
1838$(MODORDER): $(build-dir)
1839	@:
1840
1841# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1842# This is solely useful to speed up test compiles.
1843modules: modpost
1844ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1845	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1846endif
1847
1848PHONY += modules_check
1849modules_check: $(MODORDER)
1850	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1851
1852else # CONFIG_MODULES
1853
1854modules:
1855	@:
1856
1857KBUILD_MODULES :=
1858
1859endif # CONFIG_MODULES
1860
1861PHONY += modpost
1862modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1863	 $(if $(KBUILD_MODULES), modules_check)
1864	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1865
1866# Single targets
1867# ---------------------------------------------------------------------------
1868# To build individual files in subdirectories, you can do like this:
1869#
1870#   make foo/bar/baz.s
1871#
1872# The supported suffixes for single-target are listed in 'single-targets'
1873#
1874# To build only under specific subdirectories, you can do like this:
1875#
1876#   make foo/bar/baz/
1877
1878ifdef single-build
1879
1880# .ko is special because modpost is needed
1881single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1882single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1883		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1884
1885$(single-ko): single_modules
1886	@:
1887$(single-no-ko): $(build-dir)
1888	@:
1889
1890# Remove MODORDER when done because it is not the real one.
1891PHONY += single_modules
1892single_modules: $(single-no-ko) modules_prepare
1893	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1894	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1895ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1896	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1897endif
1898	$(Q)rm -f $(MODORDER)
1899
1900single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1901
1902KBUILD_MODULES := 1
1903
1904endif
1905
1906# Preset locale variables to speed up the build process. Limit locale
1907# tweaks to this spot to avoid wrong language settings when running
1908# make menuconfig etc.
1909# Error messages still appears in the original language
1910PHONY += $(build-dir)
1911$(build-dir): prepare
1912	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1913
1914clean-dirs := $(addprefix _clean_, $(clean-dirs))
1915PHONY += $(clean-dirs) clean
1916$(clean-dirs):
1917	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1918
1919clean: $(clean-dirs)
1920	$(call cmd,rmfiles)
1921	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1922		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
1923		-o -name '*.ko.*' \
1924		-o -name '*.dtb' -o -name '*.dtbo' \
1925		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
1926		-o -name '*.dt.yaml' \
1927		-o -name '*.dwo' -o -name '*.lst' \
1928		-o -name '*.su' -o -name '*.mod' \
1929		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1930		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1931		-o -name '*.asn1.[ch]' \
1932		-o -name '*.symtypes' -o -name 'modules.order' \
1933		-o -name '*.c.[012]*.*' \
1934		-o -name '*.ll' \
1935		-o -name '*.gcno' \
1936		-o -name '*.*.symversions' \) -type f -print \
1937		-o -name '.tmp_*' -print \
1938		| xargs rm -rf
1939
1940# Generate tags for editors
1941# ---------------------------------------------------------------------------
1942quiet_cmd_tags = GEN     $@
1943      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1944
1945tags TAGS cscope gtags: FORCE
1946	$(call cmd,tags)
1947
1948# IDE support targets
1949PHONY += rust-analyzer
1950rust-analyzer:
1951	$(Q)$(MAKE) $(build)=rust $@
1952
1953# Script to generate missing namespace dependencies
1954# ---------------------------------------------------------------------------
1955
1956PHONY += nsdeps
1957nsdeps: export KBUILD_NSDEPS=1
1958nsdeps: modules
1959	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1960
1961# Clang Tooling
1962# ---------------------------------------------------------------------------
1963
1964quiet_cmd_gen_compile_commands = GEN     $@
1965      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1966
1967$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1968	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
1969	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1970	$(call if_changed,gen_compile_commands)
1971
1972targets += $(extmod_prefix)compile_commands.json
1973
1974PHONY += clang-tidy clang-analyzer
1975
1976ifdef CONFIG_CC_IS_CLANG
1977quiet_cmd_clang_tools = CHECK   $<
1978      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1979
1980clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1981	$(call cmd,clang_tools)
1982else
1983clang-tidy clang-analyzer:
1984	@echo "$@ requires CC=clang" >&2
1985	@false
1986endif
1987
1988# Scripts to check various things for consistency
1989# ---------------------------------------------------------------------------
1990
1991PHONY += includecheck versioncheck coccicheck export_report
1992
1993includecheck:
1994	find $(srctree)/* $(RCS_FIND_IGNORE) \
1995		-name '*.[hcS]' -type f -print | sort \
1996		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1997
1998versioncheck:
1999	find $(srctree)/* $(RCS_FIND_IGNORE) \
2000		-name '*.[hcS]' -type f -print | sort \
2001		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2002
2003coccicheck:
2004	$(Q)$(BASH) $(srctree)/scripts/$@
2005
2006export_report:
2007	$(PERL) $(srctree)/scripts/export_report.pl
2008
2009PHONY += checkstack kernelrelease kernelversion image_name
2010
2011# UML needs a little special treatment here.  It wants to use the host
2012# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2013# else wants $(ARCH), including people doing cross-builds, which means
2014# that $(SUBARCH) doesn't work here.
2015ifeq ($(ARCH), um)
2016CHECKSTACK_ARCH := $(SUBARCH)
2017else
2018CHECKSTACK_ARCH := $(ARCH)
2019endif
2020MINSTACKSIZE	?= 100
2021checkstack:
2022	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2023	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2024
2025kernelrelease:
2026	@$(filechk_kernel.release)
2027
2028kernelversion:
2029	@echo $(KERNELVERSION)
2030
2031image_name:
2032	@echo $(KBUILD_IMAGE)
2033
2034PHONY += run-command
2035run-command:
2036	$(Q)$(KBUILD_RUN_COMMAND)
2037
2038quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2039      cmd_rmfiles = rm -rf $(rm-files)
2040
2041# read saved command lines for existing targets
2042existing-targets := $(wildcard $(sort $(targets)))
2043
2044-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2045
2046endif # config-build
2047endif # mixed-build
2048endif # need-sub-make
2049
2050PHONY += FORCE
2051FORCE:
2052
2053# Declare the contents of the PHONY variable as phony.  We keep that
2054# information in a variable so we can use it in if_changed and friends.
2055.PHONY: $(PHONY)
2056