xref: /linux/Makefile (revision 8577c9dca799bd74377f7c30015d8cdc53a53ca2)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 12
4SUBLEVEL = 0
5EXTRAVERSION = -rc2
6NAME = Baby Opossum Posse
7
8# *DOCUMENTATION*
9# To see a list of typical targets execute "make help"
10# More info can be located in ./README
11# Comments in this file are targeted only to the developer, do not
12# expect to learn how to build the kernel reading this file.
13
14ifeq ($(filter output-sync,$(.FEATURES)),)
15$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41this-makefile := $(lastword $(MAKEFILE_LIST))
42abs_srctree := $(realpath $(dir $(this-makefile)))
43abs_objtree := $(CURDIR)
44
45ifneq ($(sub_make_done),1)
46
47# Do not use make's built-in rules and variables
48# (this increases performance and avoids hard-to-debug behaviour)
49MAKEFLAGS += -rR
50
51# Avoid funny character set dependencies
52unexport LC_ALL
53LC_COLLATE=C
54LC_NUMERIC=C
55export LC_COLLATE LC_NUMERIC
56
57# Avoid interference with shell env settings
58unexport GREP_OPTIONS
59
60# Beautify output
61# ---------------------------------------------------------------------------
62#
63# Most of build commands in Kbuild start with "cmd_". You can optionally define
64# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
65# that command is printed by default.
66#
67# e.g.)
68#    quiet_cmd_depmod = DEPMOD  $(MODLIB)
69#          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
70#
71# A simple variant is to prefix commands with $(Q) - that's useful
72# for commands that shall be hidden in non-verbose mode.
73#
74#    $(Q)$(MAKE) $(build)=scripts/basic
75#
76# If KBUILD_VERBOSE contains 1, the whole command is echoed.
77# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
78#
79# To put more focus on warnings, be less verbose as default
80# Use 'make V=1' to see the full commands
81
82ifeq ("$(origin V)", "command line")
83  KBUILD_VERBOSE = $(V)
84endif
85
86quiet = quiet_
87Q = @
88
89ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
90  quiet =
91  Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),)
97quiet=silent_
98override KBUILD_VERBOSE :=
99endif
100
101export quiet Q KBUILD_VERBOSE
102
103# Call a source code checker (by default, "sparse") as part of the
104# C compilation.
105#
106# Use 'make C=1' to enable checking of only re-compiled files.
107# Use 'make C=2' to enable checking of *all* source files, regardless
108# of whether they are re-compiled or not.
109#
110# See the file "Documentation/dev-tools/sparse.rst" for more details,
111# including where to get the "sparse" utility.
112
113ifeq ("$(origin C)", "command line")
114  KBUILD_CHECKSRC = $(C)
115endif
116ifndef KBUILD_CHECKSRC
117  KBUILD_CHECKSRC = 0
118endif
119
120export KBUILD_CHECKSRC
121
122# Enable "clippy" (a linter) as part of the Rust compilation.
123#
124# Use 'make CLIPPY=1' to enable it.
125ifeq ("$(origin CLIPPY)", "command line")
126  KBUILD_CLIPPY := $(CLIPPY)
127endif
128
129export KBUILD_CLIPPY
130
131# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
132# directory of external module to build. Setting M= takes precedence.
133ifeq ("$(origin M)", "command line")
134  KBUILD_EXTMOD := $(M)
135endif
136
137$(if $(word 2, $(KBUILD_EXTMOD)), \
138	$(error building multiple external modules is not supported))
139
140$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
141	$(error module directory path cannot contain '$x')))
142
143# Remove trailing slashes
144ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
145KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
146endif
147
148export KBUILD_EXTMOD
149
150# backward compatibility
151KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
152
153ifeq ("$(origin W)", "command line")
154  KBUILD_EXTRA_WARN := $(W)
155endif
156
157export KBUILD_EXTRA_WARN
158
159# Kbuild will save output files in the current working directory.
160# This does not need to match to the root of the kernel source tree.
161#
162# For example, you can do this:
163#
164#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
165#
166# If you want to save output files in a different location, there are
167# two syntaxes to specify it.
168#
169# 1) O=
170# Use "make O=dir/to/store/output/files/"
171#
172# 2) Set KBUILD_OUTPUT
173# Set the environment variable KBUILD_OUTPUT to point to the output directory.
174# export KBUILD_OUTPUT=dir/to/store/output/files/; make
175#
176# The O= assignment takes precedence over the KBUILD_OUTPUT environment
177# variable.
178
179# Do we want to change the working directory?
180ifeq ("$(origin O)", "command line")
181  KBUILD_OUTPUT := $(O)
182endif
183
184ifneq ($(KBUILD_OUTPUT),)
185# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
186$(shell mkdir -p "$(KBUILD_OUTPUT)")
187# $(realpath ...) resolves symlinks
188abs_objtree := $(realpath $(KBUILD_OUTPUT))
189$(if $(abs_objtree),,$(error failed to create output directory "$(KBUILD_OUTPUT)"))
190endif # ifneq ($(KBUILD_OUTPUT),)
191
192ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
193$(error source directory cannot contain spaces or colons)
194endif
195
196export sub_make_done := 1
197
198endif # sub_make_done
199
200ifeq ($(abs_objtree),$(CURDIR))
201# Suppress "Entering directory ..." if we are at the final work directory.
202no-print-directory := --no-print-directory
203else
204# Recursion to show "Entering directory ..."
205need-sub-make := 1
206endif
207
208ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
209# If --no-print-directory is unset, recurse once again to set it.
210# You may end up recursing into __sub-make twice. This is needed due to the
211# behavior change in GNU Make 4.4.1.
212need-sub-make := 1
213endif
214
215ifeq ($(need-sub-make),1)
216
217PHONY += $(MAKECMDGOALS) __sub-make
218
219$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
220	@:
221
222# Invoke a second make in the output directory, passing relevant variables
223__sub-make:
224	$(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
225	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
226
227else # need-sub-make
228
229# We process the rest of the Makefile if this is the final invocation of make
230
231ifeq ($(abs_srctree),$(abs_objtree))
232        # building in the source tree
233        srctree := .
234	building_out_of_srctree :=
235else
236        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
237                # building in a subdirectory of the source tree
238                srctree := ..
239        else
240                srctree := $(abs_srctree)
241        endif
242	building_out_of_srctree := 1
243endif
244
245ifneq ($(KBUILD_ABS_SRCTREE),)
246srctree := $(abs_srctree)
247endif
248
249objtree		:= .
250
251VPATH		:=
252
253ifeq ($(KBUILD_EXTMOD),)
254ifdef building_out_of_srctree
255VPATH		:= $(srctree)
256endif
257endif
258
259export building_out_of_srctree srctree objtree VPATH
260
261# To make sure we do not include .config for any of the *config targets
262# catch them early, and hand them over to scripts/kconfig/Makefile
263# It is allowed to specify more targets when calling make, including
264# mixing *config targets and build targets.
265# For example 'make oldconfig all'.
266# Detect when mixed targets is specified, and make a second invocation
267# of make so .config is not included in this case either (for *config).
268
269version_h := include/generated/uapi/linux/version.h
270
271clean-targets := %clean mrproper cleandocs
272no-dot-config-targets := $(clean-targets) \
273			 cscope gtags TAGS tags help% %docs check% coccicheck \
274			 $(version_h) headers headers_% archheaders archscripts \
275			 %asm-generic kernelversion %src-pkg dt_binding_check \
276			 outputmakefile rustavailable rustfmt rustfmtcheck
277no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
278			  image_name
279single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
280
281config-build	:=
282mixed-build	:=
283need-config	:= 1
284may-sync-config	:= 1
285single-build	:=
286
287ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
288    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
289        need-config :=
290    endif
291endif
292
293ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
294    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
295        may-sync-config :=
296    endif
297endif
298
299need-compiler := $(may-sync-config)
300
301ifneq ($(KBUILD_EXTMOD),)
302    may-sync-config :=
303endif
304
305ifeq ($(KBUILD_EXTMOD),)
306    ifneq ($(filter %config,$(MAKECMDGOALS)),)
307        config-build := 1
308        ifneq ($(words $(MAKECMDGOALS)),1)
309            mixed-build := 1
310        endif
311    endif
312endif
313
314# We cannot build single targets and the others at the same time
315ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
316    single-build := 1
317    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
318        mixed-build := 1
319    endif
320endif
321
322# For "make -j clean all", "make -j mrproper defconfig all", etc.
323ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
324    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
325        mixed-build := 1
326    endif
327endif
328
329# install and modules_install need also be processed one by one
330ifneq ($(filter install,$(MAKECMDGOALS)),)
331    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
332        mixed-build := 1
333    endif
334endif
335
336ifdef mixed-build
337# ===========================================================================
338# We're called with mixed targets (*config and build targets).
339# Handle them one by one.
340
341PHONY += $(MAKECMDGOALS) __build_one_by_one
342
343$(MAKECMDGOALS): __build_one_by_one
344	@:
345
346__build_one_by_one:
347	$(Q)set -e; \
348	for i in $(MAKECMDGOALS); do \
349		$(MAKE) -f $(srctree)/Makefile $$i; \
350	done
351
352else # !mixed-build
353
354include $(srctree)/scripts/Kbuild.include
355
356# Read KERNELRELEASE from include/config/kernel.release (if it exists)
357KERNELRELEASE = $(call read-file, include/config/kernel.release)
358KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
359export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
360
361include $(srctree)/scripts/subarch.include
362
363# Cross compiling and selecting different set of gcc/bin-utils
364# ---------------------------------------------------------------------------
365#
366# When performing cross compilation for other architectures ARCH shall be set
367# to the target architecture. (See arch/* for the possibilities).
368# ARCH can be set during invocation of make:
369# make ARCH=arm64
370# Another way is to have ARCH set in the environment.
371# The default ARCH is the host where make is executed.
372
373# CROSS_COMPILE specify the prefix used for all executables used
374# during compilation. Only gcc and related bin-utils executables
375# are prefixed with $(CROSS_COMPILE).
376# CROSS_COMPILE can be set on the command line
377# make CROSS_COMPILE=aarch64-linux-gnu-
378# Alternatively CROSS_COMPILE can be set in the environment.
379# Default value for CROSS_COMPILE is not to prefix executables
380# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
381ARCH		?= $(SUBARCH)
382
383# Architecture as present in compile.h
384UTS_MACHINE 	:= $(ARCH)
385SRCARCH 	:= $(ARCH)
386
387# Additional ARCH settings for x86
388ifeq ($(ARCH),i386)
389        SRCARCH := x86
390endif
391ifeq ($(ARCH),x86_64)
392        SRCARCH := x86
393endif
394
395# Additional ARCH settings for sparc
396ifeq ($(ARCH),sparc32)
397       SRCARCH := sparc
398endif
399ifeq ($(ARCH),sparc64)
400       SRCARCH := sparc
401endif
402
403# Additional ARCH settings for parisc
404ifeq ($(ARCH),parisc64)
405       SRCARCH := parisc
406endif
407
408export cross_compiling :=
409ifneq ($(SRCARCH),$(SUBARCH))
410cross_compiling := 1
411endif
412
413KCONFIG_CONFIG	?= .config
414export KCONFIG_CONFIG
415
416# SHELL used by kbuild
417CONFIG_SHELL := sh
418
419HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
420HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
421HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
422
423ifneq ($(LLVM),)
424ifneq ($(filter %/,$(LLVM)),)
425LLVM_PREFIX := $(LLVM)
426else ifneq ($(filter -%,$(LLVM)),)
427LLVM_SUFFIX := $(LLVM)
428endif
429
430HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
431HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
432else
433HOSTCC	= gcc
434HOSTCXX	= g++
435endif
436HOSTRUSTC = rustc
437HOSTPKG_CONFIG	= pkg-config
438
439KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
440			 -O2 -fomit-frame-pointer -std=gnu11
441KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
442KBUILD_USERLDFLAGS := $(USERLDFLAGS)
443
444# These flags apply to all Rust code in the tree, including the kernel and
445# host programs.
446export rust_common_flags := --edition=2021 \
447			    -Zbinary_dep_depinfo=y \
448			    -Astable_features \
449			    -Dnon_ascii_idents \
450			    -Dunsafe_op_in_unsafe_fn \
451			    -Wmissing_docs \
452			    -Wrust_2018_idioms \
453			    -Wunreachable_pub \
454			    -Wclippy::all \
455			    -Wclippy::ignored_unit_patterns \
456			    -Wclippy::mut_mut \
457			    -Wclippy::needless_bitwise_bool \
458			    -Wclippy::needless_continue \
459			    -Wclippy::no_mangle_with_rust_abi \
460			    -Wclippy::undocumented_unsafe_blocks \
461			    -Wclippy::unnecessary_safety_comment \
462			    -Wclippy::unnecessary_safety_doc \
463			    -Wrustdoc::missing_crate_level_docs \
464			    -Wrustdoc::unescaped_backticks
465
466KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
467		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
468KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
469		       -I $(srctree)/scripts/include
470KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
471			-Zallow-features= $(HOSTRUSTFLAGS)
472KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
473KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
474
475# Make variables (CC, etc...)
476CPP		= $(CC) -E
477ifneq ($(LLVM),)
478CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
479LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
480AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
481NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
482OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
483OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
484READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
485STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
486else
487CC		= $(CROSS_COMPILE)gcc
488LD		= $(CROSS_COMPILE)ld
489AR		= $(CROSS_COMPILE)ar
490NM		= $(CROSS_COMPILE)nm
491OBJCOPY		= $(CROSS_COMPILE)objcopy
492OBJDUMP		= $(CROSS_COMPILE)objdump
493READELF		= $(CROSS_COMPILE)readelf
494STRIP		= $(CROSS_COMPILE)strip
495endif
496RUSTC		= rustc
497RUSTDOC		= rustdoc
498RUSTFMT		= rustfmt
499CLIPPY_DRIVER	= clippy-driver
500BINDGEN		= bindgen
501PAHOLE		= pahole
502RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
503LEX		= flex
504YACC		= bison
505AWK		= awk
506INSTALLKERNEL  := installkernel
507PERL		= perl
508PYTHON3		= python3
509CHECK		= sparse
510BASH		= bash
511KGZIP		= gzip
512KBZIP2		= bzip2
513KLZOP		= lzop
514LZMA		= lzma
515LZ4		= lz4c
516XZ		= xz
517ZSTD		= zstd
518
519CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
520		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
521NOSTDINC_FLAGS :=
522CFLAGS_MODULE   =
523RUSTFLAGS_MODULE =
524AFLAGS_MODULE   =
525LDFLAGS_MODULE  =
526CFLAGS_KERNEL	=
527RUSTFLAGS_KERNEL =
528AFLAGS_KERNEL	=
529LDFLAGS_vmlinux =
530
531# Use USERINCLUDE when you must reference the UAPI directories only.
532USERINCLUDE    := \
533		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
534		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
535		-I$(srctree)/include/uapi \
536		-I$(objtree)/include/generated/uapi \
537                -include $(srctree)/include/linux/compiler-version.h \
538                -include $(srctree)/include/linux/kconfig.h
539
540# Use LINUXINCLUDE when you must reference the include/ directory.
541# Needed to be compatible with the O= option
542LINUXINCLUDE    := \
543		-I$(srctree)/arch/$(SRCARCH)/include \
544		-I$(objtree)/arch/$(SRCARCH)/include/generated \
545		$(if $(building_out_of_srctree),-I$(srctree)/include) \
546		-I$(objtree)/include \
547		$(USERINCLUDE)
548
549KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
550
551KBUILD_CFLAGS :=
552KBUILD_CFLAGS += -std=gnu11
553KBUILD_CFLAGS += -fshort-wchar
554KBUILD_CFLAGS += -funsigned-char
555KBUILD_CFLAGS += -fno-common
556KBUILD_CFLAGS += -fno-PIE
557KBUILD_CFLAGS += -fno-strict-aliasing
558
559KBUILD_CPPFLAGS := -D__KERNEL__
560KBUILD_RUSTFLAGS := $(rust_common_flags) \
561		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
562		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
563		    -Csymbol-mangling-version=v0 \
564		    -Crelocation-model=static \
565		    -Zfunction-sections=n \
566		    -Wclippy::float_arithmetic
567
568KBUILD_AFLAGS_KERNEL :=
569KBUILD_CFLAGS_KERNEL :=
570KBUILD_RUSTFLAGS_KERNEL :=
571KBUILD_AFLAGS_MODULE  := -DMODULE
572KBUILD_CFLAGS_MODULE  := -DMODULE
573KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
574KBUILD_LDFLAGS_MODULE :=
575KBUILD_LDFLAGS :=
576CLANG_FLAGS :=
577
578ifeq ($(KBUILD_CLIPPY),1)
579	RUSTC_OR_CLIPPY_QUIET := CLIPPY
580	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
581else
582	RUSTC_OR_CLIPPY_QUIET := RUSTC
583	RUSTC_OR_CLIPPY = $(RUSTC)
584endif
585
586# Allows the usage of unstable features in stable compilers.
587export RUSTC_BOOTSTRAP := 1
588
589# Allows finding `.clippy.toml` in out-of-srctree builds.
590export CLIPPY_CONF_DIR := $(srctree)
591
592export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
593export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN
594export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
595export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
596export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
597export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
598export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
599export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
600
601export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
602export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
603export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
604export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
605export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
606export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
607
608# Files to ignore in find ... statements
609
610export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
611			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
612			  -prune -o
613
614# ===========================================================================
615# Rules shared between *config targets and build targets
616
617# Basic helpers built in scripts/basic/
618PHONY += scripts_basic
619scripts_basic:
620	$(Q)$(MAKE) $(build)=scripts/basic
621
622PHONY += outputmakefile
623ifdef building_out_of_srctree
624# Before starting out-of-tree build, make sure the source tree is clean.
625# outputmakefile generates a Makefile in the output directory, if using a
626# separate output directory. This allows convenient use of make in the
627# output directory.
628# At the same time when output Makefile generated, generate .gitignore to
629# ignore whole output directory
630
631quiet_cmd_makefile = GEN     Makefile
632      cmd_makefile = { \
633	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
634	echo "include $(srctree)/Makefile"; \
635	} > Makefile
636
637outputmakefile:
638	@if [ -f $(srctree)/.config -o \
639		 -d $(srctree)/include/config -o \
640		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
641		echo >&2 "***"; \
642		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
643		echo >&2 "*** in $(abs_srctree)";\
644		echo >&2 "***"; \
645		false; \
646	fi
647	$(Q)ln -fsn $(srctree) source
648	$(call cmd,makefile)
649	$(Q)test -e .gitignore || \
650	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
651endif
652
653# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
654# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
655# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they
656# need export), and from include/config/auto.conf.cmd to detect the compiler
657# upgrade.
658CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
659RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
660
661ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
662include $(srctree)/scripts/Makefile.clang
663endif
664
665# Include this also for config targets because some architectures need
666# cc-cross-prefix to determine CROSS_COMPILE.
667ifdef need-compiler
668include $(srctree)/scripts/Makefile.compiler
669endif
670
671ifdef config-build
672# ===========================================================================
673# *config targets only - make sure prerequisites are updated, and descend
674# in scripts/kconfig to make the *config target
675
676# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
677# KBUILD_DEFCONFIG may point out an alternative default configuration
678# used for 'make defconfig'
679include $(srctree)/arch/$(SRCARCH)/Makefile
680export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
681
682config: outputmakefile scripts_basic FORCE
683	$(Q)$(MAKE) $(build)=scripts/kconfig $@
684
685%config: outputmakefile scripts_basic FORCE
686	$(Q)$(MAKE) $(build)=scripts/kconfig $@
687
688else #!config-build
689# ===========================================================================
690# Build targets only - this includes vmlinux, arch-specific targets, clean
691# targets and others. In general all targets except *config targets.
692
693# If building an external module we do not care about the all: rule
694# but instead __all depend on modules
695PHONY += all
696ifeq ($(KBUILD_EXTMOD),)
697__all: all
698else
699__all: modules
700endif
701
702targets :=
703
704# Decide whether to build built-in, modular, or both.
705# Normally, just do built-in.
706
707KBUILD_MODULES :=
708KBUILD_BUILTIN := 1
709
710# If we have only "make modules", don't compile built-in objects.
711ifeq ($(MAKECMDGOALS),modules)
712  KBUILD_BUILTIN :=
713endif
714
715# If we have "make <whatever> modules", compile modules
716# in addition to whatever we do anyway.
717# Just "make" or "make all" shall build modules as well
718
719ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
720  KBUILD_MODULES := 1
721endif
722
723ifeq ($(MAKECMDGOALS),)
724  KBUILD_MODULES := 1
725endif
726
727export KBUILD_MODULES KBUILD_BUILTIN
728
729ifdef need-config
730include include/config/auto.conf
731endif
732
733ifeq ($(KBUILD_EXTMOD),)
734# Objects we will link into vmlinux / subdirs we need to visit
735core-y		:=
736drivers-y	:=
737libs-y		:= lib/
738endif # KBUILD_EXTMOD
739
740# The all: target is the default when no target is given on the
741# command line.
742# This allow a user to issue only 'make' to build a kernel including modules
743# Defaults to vmlinux, but the arch makefile usually adds further targets
744all: vmlinux
745
746CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
747ifdef CONFIG_CC_IS_GCC
748CFLAGS_GCOV	+= -fno-tree-loop-im
749endif
750export CFLAGS_GCOV
751
752# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
753ifdef CONFIG_FUNCTION_TRACER
754  CC_FLAGS_FTRACE := -pg
755endif
756
757include $(srctree)/arch/$(SRCARCH)/Makefile
758
759ifdef need-config
760ifdef may-sync-config
761# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
762# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
763# because some architectures define CROSS_COMPILE there.
764include include/config/auto.conf.cmd
765
766$(KCONFIG_CONFIG):
767	@echo >&2 '***'
768	@echo >&2 '*** Configuration file "$@" not found!'
769	@echo >&2 '***'
770	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
771	@echo >&2 '*** "make menuconfig" or "make xconfig").'
772	@echo >&2 '***'
773	@/bin/false
774
775# The actual configuration files used during the build are stored in
776# include/generated/ and include/config/. Update them if .config is newer than
777# include/config/auto.conf (which mirrors .config).
778#
779# This exploits the 'multi-target pattern rule' trick.
780# The syncconfig should be executed only once to make all the targets.
781# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
782#
783# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
784# so you cannot notice that Kconfig is waiting for the user input.
785%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
786	$(Q)$(kecho) "  SYNC    $@"
787	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
788else # !may-sync-config
789# External modules and some install targets need include/generated/autoconf.h
790# and include/config/auto.conf but do not care if they are up-to-date.
791# Use auto.conf to trigger the test
792PHONY += include/config/auto.conf
793
794include/config/auto.conf:
795	@test -e include/generated/autoconf.h -a -e $@ || (		\
796	echo >&2;							\
797	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
798	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
799	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
800	echo >&2 ;							\
801	/bin/false)
802
803endif # may-sync-config
804endif # need-config
805
806KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
807
808ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
809KBUILD_CFLAGS += -O2
810KBUILD_RUSTFLAGS += -Copt-level=2
811else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
812KBUILD_CFLAGS += -Os
813KBUILD_RUSTFLAGS += -Copt-level=s
814endif
815
816# Always set `debug-assertions` and `overflow-checks` because their default
817# depends on `opt-level` and `debug-assertions`, respectively.
818KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
819KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
820
821# Tell gcc to never replace conditional load with a non-conditional one
822ifdef CONFIG_CC_IS_GCC
823# gcc-10 renamed --param=allow-store-data-races=0 to
824# -fno-allow-store-data-races.
825KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
826KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
827endif
828
829ifdef CONFIG_READABLE_ASM
830# Disable optimizations that make assembler listings hard to read.
831# reorder blocks reorders the control in the function
832# ipa clone creates specialized cloned functions
833# partial inlining inlines only parts of functions
834KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
835endif
836
837stackp-flags-y                                    := -fno-stack-protector
838stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
839stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
840
841KBUILD_CFLAGS += $(stackp-flags-y)
842
843KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
844KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
845
846ifdef CONFIG_FRAME_POINTER
847KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
848KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
849else
850# Some targets (ARM with Thumb2, for example), can't be built with frame
851# pointers.  For those, we don't have FUNCTION_TRACER automatically
852# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
853# incompatible with -fomit-frame-pointer with current GCC, so we don't use
854# -fomit-frame-pointer with FUNCTION_TRACER.
855# In the Rust target specification, "frame-pointer" is set explicitly
856# to "may-omit".
857ifndef CONFIG_FUNCTION_TRACER
858KBUILD_CFLAGS	+= -fomit-frame-pointer
859endif
860endif
861
862# Initialize all stack variables with a 0xAA pattern.
863ifdef CONFIG_INIT_STACK_ALL_PATTERN
864KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
865endif
866
867# Initialize all stack variables with a zero value.
868ifdef CONFIG_INIT_STACK_ALL_ZERO
869KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
870ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
871# https://github.com/llvm/llvm-project/issues/44842
872CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
873export CC_AUTO_VAR_INIT_ZERO_ENABLER
874KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
875endif
876endif
877
878# While VLAs have been removed, GCC produces unreachable stack probes
879# for the randomize_kstack_offset feature. Disable it for all compilers.
880KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
881
882# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
883ifdef CONFIG_ZERO_CALL_USED_REGS
884KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
885endif
886
887ifdef CONFIG_FUNCTION_TRACER
888ifdef CONFIG_FTRACE_MCOUNT_USE_CC
889  CC_FLAGS_FTRACE	+= -mrecord-mcount
890  ifdef CONFIG_HAVE_NOP_MCOUNT
891    ifeq ($(call cc-option-yn, -mnop-mcount),y)
892      CC_FLAGS_FTRACE	+= -mnop-mcount
893      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
894    endif
895  endif
896endif
897ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
898  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
899    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
900  endif
901endif
902ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
903  ifdef CONFIG_HAVE_C_RECORDMCOUNT
904    BUILD_C_RECORDMCOUNT := y
905    export BUILD_C_RECORDMCOUNT
906  endif
907endif
908ifdef CONFIG_HAVE_FENTRY
909  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
910  ifeq ($(call cc-option-yn, -mfentry),y)
911    CC_FLAGS_FTRACE	+= -mfentry
912    CC_FLAGS_USING	+= -DCC_USING_FENTRY
913  endif
914endif
915export CC_FLAGS_FTRACE
916KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
917KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
918endif
919
920# We trigger additional mismatches with less inlining
921ifdef CONFIG_DEBUG_SECTION_MISMATCH
922KBUILD_CFLAGS += -fno-inline-functions-called-once
923endif
924
925# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
926ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
927KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
928KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
929LDFLAGS_vmlinux += --gc-sections
930endif
931
932ifdef CONFIG_SHADOW_CALL_STACK
933ifndef CONFIG_DYNAMIC_SCS
934CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
935KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
936KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack
937endif
938export CC_FLAGS_SCS
939endif
940
941ifdef CONFIG_LTO_CLANG
942ifdef CONFIG_LTO_CLANG_THIN
943CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
944else
945CC_FLAGS_LTO	:= -flto
946endif
947CC_FLAGS_LTO	+= -fvisibility=hidden
948
949# Limit inlining across translation units to reduce binary size
950KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
951endif
952
953ifdef CONFIG_LTO
954KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
955KBUILD_AFLAGS	+= -fno-lto
956export CC_FLAGS_LTO
957endif
958
959ifdef CONFIG_CFI_CLANG
960CC_FLAGS_CFI	:= -fsanitize=kcfi
961ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
962	CC_FLAGS_CFI	+= -fsanitize-cfi-icall-experimental-normalize-integers
963endif
964ifdef CONFIG_RUST
965	# Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects
966	# CONFIG_CFI_ICALL_NORMALIZE_INTEGERS.
967	RUSTC_FLAGS_CFI   := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers
968	KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI)
969	export RUSTC_FLAGS_CFI
970endif
971KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
972export CC_FLAGS_CFI
973endif
974
975# Architectures can define flags to add/remove for floating-point support
976CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
977export CC_FLAGS_FPU
978export CC_FLAGS_NO_FPU
979
980ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
981# Set the minimal function alignment. Use the newer GCC option
982# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
983# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
984ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
985KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
986else
987KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
988endif
989endif
990
991# arch Makefile may override CC so keep this after arch Makefile is included
992NOSTDINC_FLAGS += -nostdinc
993
994# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
995# the kernel uses only C99 flexible arrays for dynamically sized trailing
996# arrays. Enforce this for everything that may examine structure sizes and
997# perform bounds checking.
998KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
999
1000#Currently, disable -Wstringop-overflow for GCC 11, globally.
1001KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
1002KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
1003
1004# disable invalid "can't wrap" optimizations for signed / pointers
1005KBUILD_CFLAGS	+= -fno-strict-overflow
1006
1007# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1008KBUILD_CFLAGS  += -fno-stack-check
1009
1010# conserve stack if available
1011ifdef CONFIG_CC_IS_GCC
1012KBUILD_CFLAGS   += -fconserve-stack
1013endif
1014
1015# change __FILE__ to the relative path from the srctree
1016KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1017
1018# include additional Makefiles when needed
1019include-y			:= scripts/Makefile.extrawarn
1020include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1021include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1022include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1023include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1024include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1025include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1026include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1027include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1028include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1029
1030include $(addprefix $(srctree)/, $(include-y))
1031
1032# scripts/Makefile.gcc-plugins is intentionally included last.
1033# Do not add $(call cc-option,...) below this line. When you build the kernel
1034# from the clean source tree, the GCC plugins do not exist at this point.
1035
1036# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1037KBUILD_CPPFLAGS += $(KCPPFLAGS)
1038KBUILD_AFLAGS   += $(KAFLAGS)
1039KBUILD_CFLAGS   += $(KCFLAGS)
1040KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1041
1042KBUILD_LDFLAGS_MODULE += --build-id=sha1
1043LDFLAGS_vmlinux += --build-id=sha1
1044
1045KBUILD_LDFLAGS	+= -z noexecstack
1046ifeq ($(CONFIG_LD_IS_BFD),y)
1047KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1048endif
1049
1050ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1051LDFLAGS_vmlinux	+= -X
1052endif
1053
1054ifeq ($(CONFIG_RELR),y)
1055# ld.lld before 15 did not support -z pack-relative-relocs.
1056LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1057endif
1058
1059# We never want expected sections to be placed heuristically by the
1060# linker. All sections should be explicitly named in the linker script.
1061ifdef CONFIG_LD_ORPHAN_WARN
1062LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1063endif
1064
1065# Align the bit size of userspace programs with the kernel
1066KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1067KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1068
1069# make the checker run with the right architecture
1070CHECKFLAGS += --arch=$(ARCH)
1071
1072# insure the checker run with the right endianness
1073CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1074
1075# the checker needs the correct machine size
1076CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1077
1078# Default kernel image to build when no specific target is given.
1079# KBUILD_IMAGE may be overruled on the command line or
1080# set in the environment
1081# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1082# this default value
1083export KBUILD_IMAGE ?= vmlinux
1084
1085#
1086# INSTALL_PATH specifies where to place the updated kernel and system map
1087# images. Default is /boot, but you can set it to other values
1088export	INSTALL_PATH ?= /boot
1089
1090#
1091# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1092# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1093# an argument if needed. Otherwise it defaults to the kernel install path
1094#
1095export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1096
1097#
1098# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1099# relocations required by build roots.  This is not defined in the
1100# makefile but the argument can be passed to make if needed.
1101#
1102
1103MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1104export MODLIB
1105
1106PHONY += prepare0
1107
1108export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1109export MODORDER := $(extmod_prefix)modules.order
1110export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1111
1112ifeq ($(KBUILD_EXTMOD),)
1113
1114build-dir	:= .
1115clean-dirs	:= $(sort . Documentation \
1116		     $(patsubst %/,%,$(filter %/, $(core-) \
1117			$(drivers-) $(libs-))))
1118
1119export ARCH_CORE	:= $(core-y)
1120export ARCH_LIB		:= $(filter %/, $(libs-y))
1121export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1122# Externally visible symbols (used by link-vmlinux.sh)
1123
1124KBUILD_VMLINUX_OBJS := ./built-in.a
1125ifdef CONFIG_MODULES
1126KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1127KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1128else
1129KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1130endif
1131
1132export KBUILD_VMLINUX_LIBS
1133export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1134
1135ifdef CONFIG_TRIM_UNUSED_KSYMS
1136# For the kernel to actually contain only the needed exported symbols,
1137# we have to build modules as well to determine what those symbols are.
1138KBUILD_MODULES := 1
1139endif
1140
1141# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1142quiet_cmd_ar_vmlinux.a = AR      $@
1143      cmd_ar_vmlinux.a = \
1144	rm -f $@; \
1145	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1146	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1147
1148targets += vmlinux.a
1149vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1150	$(call if_changed,ar_vmlinux.a)
1151
1152PHONY += vmlinux_o
1153vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1154	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1155
1156vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1157	@:
1158
1159PHONY += vmlinux
1160# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1161# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1162# unrelated; the decompressors just happen to have the same base name,
1163# arch/*/boot/compressed/vmlinux.
1164# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1165#
1166# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1167#   https://savannah.gnu.org/bugs/?61463
1168# For Make > 4.4, the following simple code will work:
1169#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1170vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1171vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1172vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1173	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1174
1175# The actual objects are generated when descending,
1176# make sure no implicit rule kicks in
1177$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1178
1179ifeq ($(origin KERNELRELEASE),file)
1180filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1181else
1182filechk_kernel.release = echo $(KERNELRELEASE)
1183endif
1184
1185# Store (new) KERNELRELEASE string in include/config/kernel.release
1186include/config/kernel.release: FORCE
1187	$(call filechk,kernel.release)
1188
1189# Additional helpers built in scripts/
1190# Carefully list dependencies so we do not try to build scripts twice
1191# in parallel
1192PHONY += scripts
1193scripts: scripts_basic scripts_dtc
1194	$(Q)$(MAKE) $(build)=$(@)
1195
1196# Things we need to do before we recursively start building the kernel
1197# or the modules are listed in "prepare".
1198# A multi level approach is used. prepareN is processed before prepareN-1.
1199# archprepare is used in arch Makefiles and when processed asm symlink,
1200# version.h and scripts_basic is processed / created.
1201
1202PHONY += prepare archprepare
1203
1204archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1205	asm-generic $(version_h) include/generated/utsrelease.h \
1206	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1207
1208prepare0: archprepare
1209	$(Q)$(MAKE) $(build)=scripts/mod
1210	$(Q)$(MAKE) $(build)=. prepare
1211
1212# All the preparing..
1213prepare: prepare0
1214ifdef CONFIG_RUST
1215	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1216	$(Q)$(MAKE) $(build)=rust
1217endif
1218
1219PHONY += remove-stale-files
1220remove-stale-files:
1221	$(Q)$(srctree)/scripts/remove-stale-files
1222
1223# Support for using generic headers in asm-generic
1224asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1225
1226PHONY += asm-generic uapi-asm-generic
1227asm-generic: uapi-asm-generic
1228	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1229	generic=include/asm-generic
1230uapi-asm-generic:
1231	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1232	generic=include/uapi/asm-generic
1233
1234# Generate some files
1235# ---------------------------------------------------------------------------
1236
1237# KERNELRELEASE can change from a few different places, meaning version.h
1238# needs to be updated, so this check is forced on all builds
1239
1240uts_len := 64
1241define filechk_utsrelease.h
1242	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1243	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1244	  exit 1;                                                         \
1245	fi;                                                               \
1246	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1247endef
1248
1249define filechk_version.h
1250	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1251		echo \#define LINUX_VERSION_CODE $(shell                 \
1252		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1253	else                                                             \
1254		echo \#define LINUX_VERSION_CODE $(shell                 \
1255		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1256	fi;                                                              \
1257	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1258	((c) > 255 ? 255 : (c)))';                                       \
1259	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1260	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1261	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1262endef
1263
1264$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1265$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1266$(version_h): FORCE
1267	$(call filechk,version.h)
1268
1269include/generated/utsrelease.h: include/config/kernel.release FORCE
1270	$(call filechk,utsrelease.h)
1271
1272filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1273	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1274
1275include/generated/compile.h: FORCE
1276	$(call filechk,compile.h)
1277
1278PHONY += headerdep
1279headerdep:
1280	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1281	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1282
1283# ---------------------------------------------------------------------------
1284# Kernel headers
1285
1286#Default location for installed headers
1287export INSTALL_HDR_PATH = $(objtree)/usr
1288
1289quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1290      cmd_headers_install = \
1291	mkdir -p $(INSTALL_HDR_PATH); \
1292	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1293	usr/include $(INSTALL_HDR_PATH)
1294
1295PHONY += headers_install
1296headers_install: headers
1297	$(call cmd,headers_install)
1298
1299PHONY += archheaders archscripts
1300
1301hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1302
1303PHONY += headers
1304headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1305	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1306	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1307	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1308
1309ifdef CONFIG_HEADERS_INSTALL
1310prepare: headers
1311endif
1312
1313PHONY += scripts_unifdef
1314scripts_unifdef: scripts_basic
1315	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1316
1317# ---------------------------------------------------------------------------
1318# Install
1319
1320# Many distributions have the custom install script, /sbin/installkernel.
1321# If DKMS is installed, 'make install' will eventually recurse back
1322# to this Makefile to build and install external modules.
1323# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1324
1325quiet_cmd_install = INSTALL $(INSTALL_PATH)
1326      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1327
1328# ---------------------------------------------------------------------------
1329# vDSO install
1330
1331PHONY += vdso_install
1332vdso_install: export INSTALL_FILES = $(vdso-install-y)
1333vdso_install:
1334	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1335
1336# ---------------------------------------------------------------------------
1337# Tools
1338
1339ifdef CONFIG_OBJTOOL
1340prepare: tools/objtool
1341endif
1342
1343ifdef CONFIG_BPF
1344ifdef CONFIG_DEBUG_INFO_BTF
1345prepare: tools/bpf/resolve_btfids
1346endif
1347endif
1348
1349# The tools build system is not a part of Kbuild and tends to introduce
1350# its own unique issues. If you need to integrate a new tool into Kbuild,
1351# please consider locating that tool outside the tools/ tree and using the
1352# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1353# here. See Documentation/kbuild/makefiles.rst for details.
1354
1355PHONY += resolve_btfids_clean
1356
1357resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1358
1359# tools/bpf/resolve_btfids directory might not exist
1360# in output directory, skip its clean in that case
1361resolve_btfids_clean:
1362ifneq ($(wildcard $(resolve_btfids_O)),)
1363	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1364endif
1365
1366# Clear a bunch of variables before executing the submake
1367ifeq ($(quiet),silent_)
1368tools_silent=s
1369endif
1370
1371tools/: FORCE
1372	$(Q)mkdir -p $(objtree)/tools
1373	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1374
1375tools/%: FORCE
1376	$(Q)mkdir -p $(objtree)/tools
1377	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1378
1379# ---------------------------------------------------------------------------
1380# Kernel selftest
1381
1382PHONY += kselftest
1383kselftest: headers
1384	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1385
1386kselftest-%: headers FORCE
1387	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1388
1389PHONY += kselftest-merge
1390kselftest-merge:
1391	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1392	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1393		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1394	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1395
1396# ---------------------------------------------------------------------------
1397# Devicetree files
1398
1399ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1400dtstree := arch/$(SRCARCH)/boot/dts
1401endif
1402
1403ifneq ($(dtstree),)
1404
1405%.dtb: dtbs_prepare
1406	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1407
1408%.dtbo: dtbs_prepare
1409	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1410
1411PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1412dtbs: dtbs_prepare
1413	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1414
1415# include/config/kernel.release is actually needed when installing DTBs because
1416# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1417# dtbs_install depend on it as dtbs_install may run as root.
1418dtbs_prepare: include/config/kernel.release scripts_dtc
1419
1420ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1421export CHECK_DTBS=y
1422endif
1423
1424ifneq ($(CHECK_DTBS),)
1425dtbs_prepare: dt_binding_schemas
1426endif
1427
1428dtbs_check: dtbs
1429
1430dtbs_install:
1431	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1432
1433ifdef CONFIG_OF_EARLY_FLATTREE
1434all: dtbs
1435endif
1436
1437endif
1438
1439PHONY += scripts_dtc
1440scripts_dtc: scripts_basic
1441	$(Q)$(MAKE) $(build)=scripts/dtc
1442
1443ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1444export CHECK_DTBS=y
1445endif
1446
1447PHONY += dt_binding_check dt_binding_schemas
1448dt_binding_check: dt_binding_schemas scripts_dtc
1449	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1450
1451dt_binding_schemas:
1452	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1453
1454PHONY += dt_compatible_check
1455dt_compatible_check: dt_binding_schemas
1456	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1457
1458# ---------------------------------------------------------------------------
1459# Modules
1460
1461ifdef CONFIG_MODULES
1462
1463# By default, build modules as well
1464
1465all: modules
1466
1467# When we're building modules with modversions, we need to consider
1468# the built-in objects during the descend as well, in order to
1469# make sure the checksums are up to date before we record them.
1470ifdef CONFIG_MODVERSIONS
1471  KBUILD_BUILTIN := 1
1472endif
1473
1474# Build modules
1475#
1476
1477# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1478# is an exception.
1479ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1480KBUILD_BUILTIN := 1
1481modules: vmlinux
1482endif
1483
1484modules: modules_prepare
1485
1486# Target to prepare building external modules
1487modules_prepare: prepare
1488	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1489
1490endif # CONFIG_MODULES
1491
1492###
1493# Cleaning is done on three levels.
1494# make clean     Delete most generated files
1495#                Leave enough to build external modules
1496# make mrproper  Delete the current configuration, and all generated files
1497# make distclean Remove editor backup files, patch leftover files and the like
1498
1499# Directories & files removed with 'make clean'
1500CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1501	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1502	       modules.builtin.ranges vmlinux.o.map \
1503	       compile_commands.json rust/test \
1504	       rust-project.json .vmlinux.objs .vmlinux.export.c
1505
1506# Directories & files removed with 'make mrproper'
1507MRPROPER_FILES += include/config include/generated          \
1508		  arch/$(SRCARCH)/include/generated .objdiff \
1509		  debian snap tar-install PKGBUILD pacman \
1510		  .config .config.old .version \
1511		  Module.symvers \
1512		  certs/signing_key.pem \
1513		  certs/x509.genkey \
1514		  vmlinux-gdb.py \
1515		  rpmbuild \
1516		  rust/libmacros.so
1517
1518# clean - Delete most, but leave enough to build external modules
1519#
1520clean: private rm-files := $(CLEAN_FILES)
1521
1522PHONY += archclean vmlinuxclean
1523
1524vmlinuxclean:
1525	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1526	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1527
1528clean: archclean vmlinuxclean resolve_btfids_clean
1529
1530# mrproper - Delete all generated files, including .config
1531#
1532mrproper: private rm-files := $(MRPROPER_FILES)
1533mrproper-dirs      := $(addprefix _mrproper_,scripts)
1534
1535PHONY += $(mrproper-dirs) mrproper
1536$(mrproper-dirs):
1537	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1538
1539mrproper: clean $(mrproper-dirs)
1540	$(call cmd,rmfiles)
1541	@find . $(RCS_FIND_IGNORE) \
1542		\( -name '*.rmeta' \) \
1543		-type f -print | xargs rm -f
1544
1545# distclean
1546#
1547PHONY += distclean
1548
1549distclean: mrproper
1550	@find . $(RCS_FIND_IGNORE) \
1551		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1552		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1553		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1554		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1555		-type f -print | xargs rm -f
1556
1557
1558# Packaging of the kernel to various formats
1559# ---------------------------------------------------------------------------
1560
1561%src-pkg: FORCE
1562	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1563%pkg: include/config/kernel.release FORCE
1564	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1565
1566# Brief documentation of the typical targets used
1567# ---------------------------------------------------------------------------
1568
1569boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1570boards := $(sort $(notdir $(boards)))
1571board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1572board-dirs := $(sort $(notdir $(board-dirs:/=)))
1573
1574PHONY += help
1575help:
1576	@echo  'Cleaning targets:'
1577	@echo  '  clean		  - Remove most generated files but keep the config and'
1578	@echo  '                    enough build support to build external modules'
1579	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1580	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1581	@echo  ''
1582	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1583	@echo  ''
1584	@echo  'Other generic targets:'
1585	@echo  '  all		  - Build all targets marked with [*]'
1586	@echo  '* vmlinux	  - Build the bare kernel'
1587	@echo  '* modules	  - Build all modules'
1588	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1589	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1590	@echo  '  dir/            - Build all files in dir and below'
1591	@echo  '  dir/file.[ois]  - Build specified target only'
1592	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1593	@echo  '                    (requires compiler support for LLVM assembly generation)'
1594	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1595	@echo  '                    (requires a recent binutils and recent build (System.map))'
1596	@echo  '  dir/file.ko     - Build module including final link'
1597	@echo  '  modules_prepare - Set up for building external modules'
1598	@echo  '  tags/TAGS	  - Generate tags file for editors'
1599	@echo  '  cscope	  - Generate cscope index'
1600	@echo  '  gtags           - Generate GNU GLOBAL index'
1601	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1602	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1603	@echo  '  image_name	  - Output the image name (use with make -s)'
1604	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1605	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1606	 echo  ''
1607	@echo  'Static analysers:'
1608	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1609	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1610	@echo  '  versioncheck    - Sanity check on version.h usage'
1611	@echo  '  includecheck    - Check for duplicate included header files'
1612	@echo  '  export_report   - List the usages of all exported symbols'
1613	@echo  '  headerdep       - Detect inclusion cycles in headers'
1614	@echo  '  coccicheck      - Check with Coccinelle'
1615	@echo  '  clang-analyzer  - Check with clang static analyzer'
1616	@echo  '  clang-tidy      - Check with clang-tidy'
1617	@echo  ''
1618	@echo  'Tools:'
1619	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1620	@echo  ''
1621	@echo  'Kernel selftest:'
1622	@echo  '  kselftest         - Build and run kernel selftest'
1623	@echo  '                      Build, install, and boot kernel before'
1624	@echo  '                      running kselftest on it'
1625	@echo  '                      Run as root for full coverage'
1626	@echo  '  kselftest-all     - Build kernel selftest'
1627	@echo  '  kselftest-install - Build and install kernel selftest'
1628	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1629	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1630	@echo  '		      kselftest to existing .config.'
1631	@echo  ''
1632	@echo  'Rust targets:'
1633	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1634	@echo  '		    available and, if not, explains why.'
1635	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1636	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1637	@echo  '		    is formatted, printing a diff otherwise.'
1638	@echo  '  rustdoc	  - Generate Rust documentation'
1639	@echo  '		    (requires kernel .config)'
1640	@echo  '  rusttest        - Runs the Rust tests'
1641	@echo  '                    (requires kernel .config; downloads external repos)'
1642	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1643	@echo  '		    (requires kernel .config)'
1644	@echo  '  dir/file.[os]   - Build specified target only'
1645	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1646	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1647	@echo  '                    The output is not intended to be compilable.'
1648	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1649	@echo  ''
1650	@$(if $(dtstree), \
1651		echo 'Devicetree:'; \
1652		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1653		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1654		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1655		echo '  dt_binding_schemas - Build processed device tree binding schemas'; \
1656		echo '  dtbs_check         - Validate device tree source files';\
1657		echo '')
1658
1659	@echo 'Userspace tools targets:'
1660	@echo '  use "make tools/help"'
1661	@echo '  or  "cd tools; make help"'
1662	@echo  ''
1663	@echo  'Kernel packaging:'
1664	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1665	@echo  ''
1666	@echo  'Documentation targets:'
1667	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1668	@echo  ''
1669	@echo  'Architecture-specific targets ($(SRCARCH)):'
1670	@$(or $(archhelp),\
1671		echo '  No architecture-specific help defined for $(SRCARCH)')
1672	@echo  ''
1673	@$(if $(boards), \
1674		$(foreach b, $(boards), \
1675		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1676		echo '')
1677	@$(if $(board-dirs), \
1678		$(foreach b, $(board-dirs), \
1679		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1680		printf "  %-16s - Show all of the above\\n" help-boards; \
1681		echo '')
1682
1683	@echo  '  make V=n   [targets] 1: verbose build'
1684	@echo  '                       2: give reason for rebuild of target'
1685	@echo  '                       V=1 and V=2 can be combined with V=12'
1686	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1687	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1688	@echo  '                       (sparse by default)'
1689	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1690	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1691	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1692	@echo  '		1: warnings which may be relevant and do not occur too often'
1693	@echo  '		2: warnings which occur quite often but may still be relevant'
1694	@echo  '		3: more obscure warnings, can most likely be ignored'
1695	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1696	@echo  '		e: warnings are being treated as errors'
1697	@echo  '		Multiple levels can be combined with W=12 or W=123'
1698	@$(if $(dtstree), \
1699		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1700		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1701		)
1702	@echo  ''
1703	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1704	@echo  'For further info see the ./README file'
1705
1706
1707help-board-dirs := $(addprefix help-,$(board-dirs))
1708
1709help-boards: $(help-board-dirs)
1710
1711boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1712
1713$(help-board-dirs): help-%:
1714	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1715	@$(if $(boards-per-dir), \
1716		$(foreach b, $(boards-per-dir), \
1717		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1718		echo '')
1719
1720
1721# Documentation targets
1722# ---------------------------------------------------------------------------
1723DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1724	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1725PHONY += $(DOC_TARGETS)
1726$(DOC_TARGETS):
1727	$(Q)$(MAKE) $(build)=Documentation $@
1728
1729
1730# Rust targets
1731# ---------------------------------------------------------------------------
1732
1733# "Is Rust available?" target
1734PHONY += rustavailable
1735rustavailable:
1736	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1737
1738# Documentation target
1739#
1740# Using the singular to avoid running afoul of `no-dot-config-targets`.
1741PHONY += rustdoc
1742rustdoc: prepare
1743	$(Q)$(MAKE) $(build)=rust $@
1744
1745# Testing target
1746PHONY += rusttest
1747rusttest: prepare
1748	$(Q)$(MAKE) $(build)=rust $@
1749
1750# Formatting targets
1751PHONY += rustfmt rustfmtcheck
1752
1753# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1754#
1755# We match using absolute paths since `find` does not resolve them
1756# when matching, which is a problem when e.g. `srctree` is `..`.
1757# We `grep` afterwards in order to remove the directory entry itself.
1758rustfmt:
1759	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1760		-o -path $(abs_srctree)/rust/alloc -prune \
1761		-o -path $(abs_objtree)/rust/test -prune \
1762		| grep -Fv $(abs_srctree)/rust/alloc \
1763		| grep -Fv $(abs_objtree)/rust/test \
1764		| grep -Fv generated \
1765		| xargs $(RUSTFMT) $(rustfmt_flags)
1766
1767rustfmtcheck: rustfmt_flags = --check
1768rustfmtcheck: rustfmt
1769
1770# Misc
1771# ---------------------------------------------------------------------------
1772
1773PHONY += misc-check
1774misc-check:
1775	$(Q)$(srctree)/scripts/misc-check
1776
1777all: misc-check
1778
1779PHONY += scripts_gdb
1780scripts_gdb: prepare0
1781	$(Q)$(MAKE) $(build)=scripts/gdb
1782	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1783
1784ifdef CONFIG_GDB_SCRIPTS
1785all: scripts_gdb
1786endif
1787
1788else # KBUILD_EXTMOD
1789
1790filechk_kernel.release = echo $(KERNELRELEASE)
1791
1792###
1793# External module support.
1794# When building external modules the kernel used as basis is considered
1795# read-only, and no consistency checks are made and the make
1796# system is not used on the basis kernel. If updates are required
1797# in the basis kernel ordinary make commands (without M=...) must be used.
1798
1799# We are always building only modules.
1800KBUILD_BUILTIN :=
1801KBUILD_MODULES := 1
1802
1803build-dir := $(KBUILD_EXTMOD)
1804
1805compile_commands.json: $(extmod_prefix)compile_commands.json
1806PHONY += compile_commands.json
1807
1808clean-dirs := $(KBUILD_EXTMOD)
1809clean: private rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1810	$(KBUILD_EXTMOD)/compile_commands.json
1811
1812PHONY += prepare
1813# now expand this into a simple variable to reduce the cost of shell evaluations
1814prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1815prepare:
1816	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1817		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1818		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1819		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1820	fi
1821
1822PHONY += help
1823help:
1824	@echo  '  Building external modules.'
1825	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1826	@echo  ''
1827	@echo  '  modules         - default target, build the module(s)'
1828	@echo  '  modules_install - install the module'
1829	@echo  '  clean           - remove generated files in module directory only'
1830	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1831	@echo  ''
1832
1833ifndef CONFIG_MODULES
1834modules modules_install: __external_modules_error
1835__external_modules_error:
1836	@echo >&2 '***'
1837	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1838	@echo >&2 '*** You cannot build or install external modules.'
1839	@echo >&2 '***'
1840	@false
1841endif
1842
1843endif # KBUILD_EXTMOD
1844
1845# ---------------------------------------------------------------------------
1846# Modules
1847
1848PHONY += modules modules_install modules_sign modules_prepare
1849
1850modules_install:
1851	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1852	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1853
1854ifeq ($(CONFIG_MODULE_SIG),y)
1855# modules_sign is a subset of modules_install.
1856# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1857modules_sign: modules_install
1858	@:
1859else
1860modules_sign:
1861	@echo >&2 '***'
1862	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1863	@echo >&2 '***'
1864	@false
1865endif
1866
1867ifdef CONFIG_MODULES
1868
1869$(MODORDER): $(build-dir)
1870	@:
1871
1872# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1873# This is solely useful to speed up test compiles.
1874modules: modpost
1875ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1876	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1877endif
1878
1879PHONY += modules_check
1880modules_check: $(MODORDER)
1881	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1882
1883else # CONFIG_MODULES
1884
1885modules:
1886	@:
1887
1888KBUILD_MODULES :=
1889
1890endif # CONFIG_MODULES
1891
1892PHONY += modpost
1893modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1894	 $(if $(KBUILD_MODULES), modules_check)
1895	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1896
1897# Single targets
1898# ---------------------------------------------------------------------------
1899# To build individual files in subdirectories, you can do like this:
1900#
1901#   make foo/bar/baz.s
1902#
1903# The supported suffixes for single-target are listed in 'single-targets'
1904#
1905# To build only under specific subdirectories, you can do like this:
1906#
1907#   make foo/bar/baz/
1908
1909ifdef single-build
1910
1911# .ko is special because modpost is needed
1912single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1913single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1914		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1915
1916$(single-ko): single_modules
1917	@:
1918$(single-no-ko): $(build-dir)
1919	@:
1920
1921# Remove MODORDER when done because it is not the real one.
1922PHONY += single_modules
1923single_modules: $(single-no-ko) modules_prepare
1924	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1925	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1926ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1927	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1928endif
1929	$(Q)rm -f $(MODORDER)
1930
1931single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1932
1933KBUILD_MODULES := 1
1934
1935endif
1936
1937# Preset locale variables to speed up the build process. Limit locale
1938# tweaks to this spot to avoid wrong language settings when running
1939# make menuconfig etc.
1940# Error messages still appears in the original language
1941PHONY += $(build-dir)
1942$(build-dir): prepare
1943	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1944
1945clean-dirs := $(addprefix _clean_, $(clean-dirs))
1946PHONY += $(clean-dirs) clean
1947$(clean-dirs):
1948	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1949
1950clean: $(clean-dirs)
1951	$(call cmd,rmfiles)
1952	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1953		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
1954		-o -name '*.ko.*' \
1955		-o -name '*.dtb' -o -name '*.dtbo' \
1956		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
1957		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
1958		-o -name '*.dwo' -o -name '*.lst' \
1959		-o -name '*.su' -o -name '*.mod' \
1960		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1961		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1962		-o -name '*.asn1.[ch]' \
1963		-o -name '*.symtypes' -o -name 'modules.order' \
1964		-o -name '*.c.[012]*.*' \
1965		-o -name '*.ll' \
1966		-o -name '*.gcno' \
1967		\) -type f -print \
1968		-o -name '.tmp_*' -print \
1969		| xargs rm -rf
1970
1971# Generate tags for editors
1972# ---------------------------------------------------------------------------
1973quiet_cmd_tags = GEN     $@
1974      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1975
1976tags TAGS cscope gtags: FORCE
1977	$(call cmd,tags)
1978
1979# Generate rust-project.json (a file that describes the structure of non-Cargo
1980# Rust projects) for rust-analyzer (an implementation of the Language Server
1981# Protocol).
1982PHONY += rust-analyzer
1983rust-analyzer:
1984	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1985	$(Q)$(MAKE) $(build)=rust $@
1986
1987# Script to generate missing namespace dependencies
1988# ---------------------------------------------------------------------------
1989
1990PHONY += nsdeps
1991nsdeps: export KBUILD_NSDEPS=1
1992nsdeps: modules
1993	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1994
1995# Clang Tooling
1996# ---------------------------------------------------------------------------
1997
1998quiet_cmd_gen_compile_commands = GEN     $@
1999      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2000
2001$(extmod_prefix)compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py \
2002	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2003	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2004	$(call if_changed,gen_compile_commands)
2005
2006targets += $(extmod_prefix)compile_commands.json
2007
2008PHONY += clang-tidy clang-analyzer
2009
2010ifdef CONFIG_CC_IS_CLANG
2011quiet_cmd_clang_tools = CHECK   $<
2012      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2013
2014clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2015	$(call cmd,clang_tools)
2016else
2017clang-tidy clang-analyzer:
2018	@echo "$@ requires CC=clang" >&2
2019	@false
2020endif
2021
2022# Scripts to check various things for consistency
2023# ---------------------------------------------------------------------------
2024
2025PHONY += includecheck versioncheck coccicheck export_report
2026
2027includecheck:
2028	find $(srctree)/* $(RCS_FIND_IGNORE) \
2029		-name '*.[hcS]' -type f -print | sort \
2030		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2031
2032versioncheck:
2033	find $(srctree)/* $(RCS_FIND_IGNORE) \
2034		-name '*.[hcS]' -type f -print | sort \
2035		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2036
2037coccicheck:
2038	$(Q)$(BASH) $(srctree)/scripts/$@
2039
2040export_report:
2041	$(PERL) $(srctree)/scripts/export_report.pl
2042
2043PHONY += checkstack kernelrelease kernelversion image_name
2044
2045# UML needs a little special treatment here.  It wants to use the host
2046# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2047# else wants $(ARCH), including people doing cross-builds, which means
2048# that $(SUBARCH) doesn't work here.
2049ifeq ($(ARCH), um)
2050CHECKSTACK_ARCH := $(SUBARCH)
2051else
2052CHECKSTACK_ARCH := $(ARCH)
2053endif
2054MINSTACKSIZE	?= 100
2055checkstack:
2056	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2057	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2058
2059kernelrelease:
2060	@$(filechk_kernel.release)
2061
2062kernelversion:
2063	@echo $(KERNELVERSION)
2064
2065image_name:
2066	@echo $(KBUILD_IMAGE)
2067
2068PHONY += run-command
2069run-command:
2070	$(Q)$(KBUILD_RUN_COMMAND)
2071
2072quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2073      cmd_rmfiles = rm -rf $(rm-files)
2074
2075# read saved command lines for existing targets
2076existing-targets := $(wildcard $(sort $(targets)))
2077
2078-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2079
2080endif # config-build
2081endif # mixed-build
2082endif # need-sub-make
2083
2084PHONY += FORCE
2085FORCE:
2086
2087# Declare the contents of the PHONY variable as phony.  We keep that
2088# information in a variable so we can use it in if_changed and friends.
2089.PHONY: $(PHONY)
2090