xref: /openbmc/linux/Makefile (revision cec148c2)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 5
4SUBLEVEL = 0
5EXTRAVERSION = -rc2
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 $(KBUILD_EXTMOD).)
154endif
155
156export KBUILD_EXTMOD
157
158# Kbuild will save output files in the current working directory.
159# This does not need to match to the root of the kernel source tree.
160#
161# For example, you can do this:
162#
163#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
164#
165# If you want to save output files in a different location, there are
166# two syntaxes to specify it.
167#
168# 1) O=
169# Use "make O=dir/to/store/output/files/"
170#
171# 2) Set KBUILD_OUTPUT
172# Set the environment variable KBUILD_OUTPUT to point to the output directory.
173# export KBUILD_OUTPUT=dir/to/store/output/files/; make
174#
175# The O= assignment takes precedence over the KBUILD_OUTPUT environment
176# variable.
177
178# Do we want to change the working directory?
179ifeq ("$(origin O)", "command line")
180  KBUILD_OUTPUT := $(O)
181endif
182
183ifneq ($(KBUILD_OUTPUT),)
184# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
185# expand a shell special character '~'. We use a somewhat tedious way here.
186abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
187$(if $(abs_objtree),, \
188     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
189
190# $(realpath ...) resolves symlinks
191abs_objtree := $(realpath $(abs_objtree))
192endif # ifneq ($(KBUILD_OUTPUT),)
193
194ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
195$(error source directory cannot contain spaces or colons)
196endif
197
198ifneq ($(filter 3.%,$(MAKE_VERSION)),)
199# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
200# We need to invoke sub-make to avoid implicit rules in the top Makefile.
201need-sub-make := 1
202# Cancel implicit rules for this Makefile.
203$(this-makefile): ;
204endif
205
206export sub_make_done := 1
207
208endif # sub_make_done
209
210ifeq ($(abs_objtree),$(CURDIR))
211# Suppress "Entering directory ..." if we are at the final work directory.
212no-print-directory := --no-print-directory
213else
214# Recursion to show "Entering directory ..."
215need-sub-make := 1
216endif
217
218ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
219# If --no-print-directory is unset, recurse once again to set it.
220# You may end up recursing into __sub-make twice. This is needed due to the
221# behavior change in GNU Make 4.4.1.
222need-sub-make := 1
223endif
224
225ifeq ($(need-sub-make),1)
226
227PHONY += $(MAKECMDGOALS) __sub-make
228
229$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
230	@:
231
232# Invoke a second make in the output directory, passing relevant variables
233__sub-make:
234	$(Q)$(MAKE) $(no-print-directory) -C $(abs_objtree) \
235	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
236
237else # need-sub-make
238
239# We process the rest of the Makefile if this is the final invocation of make
240
241ifeq ($(abs_srctree),$(abs_objtree))
242        # building in the source tree
243        srctree := .
244	building_out_of_srctree :=
245else
246        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
247                # building in a subdirectory of the source tree
248                srctree := ..
249        else
250                srctree := $(abs_srctree)
251        endif
252	building_out_of_srctree := 1
253endif
254
255ifneq ($(KBUILD_ABS_SRCTREE),)
256srctree := $(abs_srctree)
257endif
258
259objtree		:= .
260VPATH		:= $(srctree)
261
262export building_out_of_srctree srctree objtree VPATH
263
264# To make sure we do not include .config for any of the *config targets
265# catch them early, and hand them over to scripts/kconfig/Makefile
266# It is allowed to specify more targets when calling make, including
267# mixing *config targets and build targets.
268# For example 'make oldconfig all'.
269# Detect when mixed targets is specified, and make a second invocation
270# of make so .config is not included in this case either (for *config).
271
272version_h := include/generated/uapi/linux/version.h
273
274clean-targets := %clean mrproper cleandocs
275no-dot-config-targets := $(clean-targets) \
276			 cscope gtags TAGS tags help% %docs check% coccicheck \
277			 $(version_h) headers headers_% archheaders archscripts \
278			 %asm-generic kernelversion %src-pkg dt_binding_check \
279			 outputmakefile rustavailable rustfmt rustfmtcheck
280# Installation targets should not require compiler. Unfortunately, vdso_install
281# is an exception where build artifacts may be updated. This must be fixed.
282no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
283			headers_install modules_install kernelrelease image_name
284no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
285			  image_name
286single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
287
288config-build	:=
289mixed-build	:=
290need-config	:= 1
291need-compiler	:= 1
292may-sync-config	:= 1
293single-build	:=
294
295ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
296	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
297		need-config :=
298	endif
299endif
300
301ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
302	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
303		need-compiler :=
304	endif
305endif
306
307ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
308	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
309		may-sync-config :=
310	endif
311endif
312
313ifneq ($(KBUILD_EXTMOD),)
314	may-sync-config :=
315endif
316
317ifeq ($(KBUILD_EXTMOD),)
318        ifneq ($(filter %config,$(MAKECMDGOALS)),)
319		config-build := 1
320                ifneq ($(words $(MAKECMDGOALS)),1)
321			mixed-build := 1
322                endif
323        endif
324endif
325
326# We cannot build single targets and the others at the same time
327ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
328	single-build := 1
329	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
330		mixed-build := 1
331	endif
332endif
333
334# For "make -j clean all", "make -j mrproper defconfig all", etc.
335ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
336        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
337		mixed-build := 1
338        endif
339endif
340
341# install and modules_install need also be processed one by one
342ifneq ($(filter install,$(MAKECMDGOALS)),)
343        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
344		mixed-build := 1
345        endif
346endif
347
348ifdef mixed-build
349# ===========================================================================
350# We're called with mixed targets (*config and build targets).
351# Handle them one by one.
352
353PHONY += $(MAKECMDGOALS) __build_one_by_one
354
355$(MAKECMDGOALS): __build_one_by_one
356	@:
357
358__build_one_by_one:
359	$(Q)set -e; \
360	for i in $(MAKECMDGOALS); do \
361		$(MAKE) -f $(srctree)/Makefile $$i; \
362	done
363
364else # !mixed-build
365
366include $(srctree)/scripts/Kbuild.include
367
368# Read KERNELRELEASE from include/config/kernel.release (if it exists)
369KERNELRELEASE = $(call read-file, include/config/kernel.release)
370KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
371export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
372
373include $(srctree)/scripts/subarch.include
374
375# Cross compiling and selecting different set of gcc/bin-utils
376# ---------------------------------------------------------------------------
377#
378# When performing cross compilation for other architectures ARCH shall be set
379# to the target architecture. (See arch/* for the possibilities).
380# ARCH can be set during invocation of make:
381# make ARCH=ia64
382# Another way is to have ARCH set in the environment.
383# The default ARCH is the host where make is executed.
384
385# CROSS_COMPILE specify the prefix used for all executables used
386# during compilation. Only gcc and related bin-utils executables
387# are prefixed with $(CROSS_COMPILE).
388# CROSS_COMPILE can be set on the command line
389# make CROSS_COMPILE=ia64-linux-
390# Alternatively CROSS_COMPILE can be set in the environment.
391# Default value for CROSS_COMPILE is not to prefix executables
392# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
393ARCH		?= $(SUBARCH)
394
395# Architecture as present in compile.h
396UTS_MACHINE 	:= $(ARCH)
397SRCARCH 	:= $(ARCH)
398
399# Additional ARCH settings for x86
400ifeq ($(ARCH),i386)
401        SRCARCH := x86
402endif
403ifeq ($(ARCH),x86_64)
404        SRCARCH := x86
405endif
406
407# Additional ARCH settings for sparc
408ifeq ($(ARCH),sparc32)
409       SRCARCH := sparc
410endif
411ifeq ($(ARCH),sparc64)
412       SRCARCH := sparc
413endif
414
415# Additional ARCH settings for parisc
416ifeq ($(ARCH),parisc64)
417       SRCARCH := parisc
418endif
419
420export cross_compiling :=
421ifneq ($(SRCARCH),$(SUBARCH))
422cross_compiling := 1
423endif
424
425KCONFIG_CONFIG	?= .config
426export KCONFIG_CONFIG
427
428# SHELL used by kbuild
429CONFIG_SHELL := sh
430
431HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
432HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
433HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
434
435ifneq ($(LLVM),)
436ifneq ($(filter %/,$(LLVM)),)
437LLVM_PREFIX := $(LLVM)
438else ifneq ($(filter -%,$(LLVM)),)
439LLVM_SUFFIX := $(LLVM)
440endif
441
442HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
443HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
444else
445HOSTCC	= gcc
446HOSTCXX	= g++
447endif
448HOSTRUSTC = rustc
449HOSTPKG_CONFIG	= pkg-config
450
451KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
452			 -O2 -fomit-frame-pointer -std=gnu11
453KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
454KBUILD_USERLDFLAGS := $(USERLDFLAGS)
455
456# These flags apply to all Rust code in the tree, including the kernel and
457# host programs.
458export rust_common_flags := --edition=2021 \
459			    -Zbinary_dep_depinfo=y \
460			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
461			    -Dunreachable_pub -Dnon_ascii_idents \
462			    -Wmissing_docs \
463			    -Drustdoc::missing_crate_level_docs \
464			    -Dclippy::correctness -Dclippy::style \
465			    -Dclippy::suspicious -Dclippy::complexity \
466			    -Dclippy::perf \
467			    -Dclippy::let_unit_value -Dclippy::mut_mut \
468			    -Dclippy::needless_bitwise_bool \
469			    -Dclippy::needless_continue \
470			    -Wclippy::dbg_macro
471
472KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
473KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
474KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
475			-Zallow-features= $(HOSTRUSTFLAGS)
476KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
477KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
478
479# Make variables (CC, etc...)
480CPP		= $(CC) -E
481ifneq ($(LLVM),)
482CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
483LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
484AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
485NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
486OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
487OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
488READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
489STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
490else
491CC		= $(CROSS_COMPILE)gcc
492LD		= $(CROSS_COMPILE)ld
493AR		= $(CROSS_COMPILE)ar
494NM		= $(CROSS_COMPILE)nm
495OBJCOPY		= $(CROSS_COMPILE)objcopy
496OBJDUMP		= $(CROSS_COMPILE)objdump
497READELF		= $(CROSS_COMPILE)readelf
498STRIP		= $(CROSS_COMPILE)strip
499endif
500RUSTC		= rustc
501RUSTDOC		= rustdoc
502RUSTFMT		= rustfmt
503CLIPPY_DRIVER	= clippy-driver
504BINDGEN		= bindgen
505CARGO		= cargo
506PAHOLE		= pahole
507RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
508LEX		= flex
509YACC		= bison
510AWK		= awk
511INSTALLKERNEL  := installkernel
512DEPMOD		= depmod
513PERL		= perl
514PYTHON3		= python3
515CHECK		= sparse
516BASH		= bash
517KGZIP		= gzip
518KBZIP2		= bzip2
519KLZOP		= lzop
520LZMA		= lzma
521LZ4		= lz4c
522XZ		= xz
523ZSTD		= zstd
524
525PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
526
527CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
528		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
529NOSTDINC_FLAGS :=
530CFLAGS_MODULE   =
531RUSTFLAGS_MODULE =
532AFLAGS_MODULE   =
533LDFLAGS_MODULE  =
534CFLAGS_KERNEL	=
535RUSTFLAGS_KERNEL =
536AFLAGS_KERNEL	=
537LDFLAGS_vmlinux =
538
539# Use USERINCLUDE when you must reference the UAPI directories only.
540USERINCLUDE    := \
541		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
542		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
543		-I$(srctree)/include/uapi \
544		-I$(objtree)/include/generated/uapi \
545                -include $(srctree)/include/linux/compiler-version.h \
546                -include $(srctree)/include/linux/kconfig.h
547
548# Use LINUXINCLUDE when you must reference the include/ directory.
549# Needed to be compatible with the O= option
550LINUXINCLUDE    := \
551		-I$(srctree)/arch/$(SRCARCH)/include \
552		-I$(objtree)/arch/$(SRCARCH)/include/generated \
553		$(if $(building_out_of_srctree),-I$(srctree)/include) \
554		-I$(objtree)/include \
555		$(USERINCLUDE)
556
557KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
558KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
559		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
560		   -Werror=implicit-function-declaration -Werror=implicit-int \
561		   -Werror=return-type -Wno-format-security -funsigned-char \
562		   -std=gnu11
563KBUILD_CPPFLAGS := -D__KERNEL__
564KBUILD_RUSTFLAGS := $(rust_common_flags) \
565		    --target=$(objtree)/scripts/target.json \
566		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
567		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
568		    -Csymbol-mangling-version=v0 \
569		    -Crelocation-model=static \
570		    -Zfunction-sections=n \
571		    -Dclippy::float_arithmetic
572
573KBUILD_AFLAGS_KERNEL :=
574KBUILD_CFLAGS_KERNEL :=
575KBUILD_RUSTFLAGS_KERNEL :=
576KBUILD_AFLAGS_MODULE  := -DMODULE
577KBUILD_CFLAGS_MODULE  := -DMODULE
578KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
579KBUILD_LDFLAGS_MODULE :=
580KBUILD_LDFLAGS :=
581CLANG_FLAGS :=
582
583ifeq ($(KBUILD_CLIPPY),1)
584	RUSTC_OR_CLIPPY_QUIET := CLIPPY
585	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
586else
587	RUSTC_OR_CLIPPY_QUIET := RUSTC
588	RUSTC_OR_CLIPPY = $(RUSTC)
589endif
590
591ifdef RUST_LIB_SRC
592	export RUST_LIB_SRC
593endif
594
595# Allows the usage of unstable features in stable compilers.
596export RUSTC_BOOTSTRAP := 1
597
598export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
599export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
600export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
601export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
602export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
603export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
604export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
605export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
606
607export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
608export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
609export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
610export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
611export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
612export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
613export PAHOLE_FLAGS
614
615# Files to ignore in find ... statements
616
617export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
618			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
619			  -prune -o
620export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
621			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
622
623# ===========================================================================
624# Rules shared between *config targets and build targets
625
626# Basic helpers built in scripts/basic/
627PHONY += scripts_basic
628scripts_basic:
629	$(Q)$(MAKE) $(build)=scripts/basic
630
631PHONY += outputmakefile
632ifdef building_out_of_srctree
633# Before starting out-of-tree build, make sure the source tree is clean.
634# outputmakefile generates a Makefile in the output directory, if using a
635# separate output directory. This allows convenient use of make in the
636# output directory.
637# At the same time when output Makefile generated, generate .gitignore to
638# ignore whole output directory
639
640quiet_cmd_makefile = GEN     Makefile
641      cmd_makefile = { \
642	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
643	echo "include $(srctree)/Makefile"; \
644	} > Makefile
645
646outputmakefile:
647	@if [ -f $(srctree)/.config -o \
648		 -d $(srctree)/include/config -o \
649		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
650		echo >&2 "***"; \
651		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
652		echo >&2 "*** in $(abs_srctree)";\
653		echo >&2 "***"; \
654		false; \
655	fi
656	$(Q)ln -fsn $(srctree) source
657	$(call cmd,makefile)
658	$(Q)test -e .gitignore || \
659	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
660endif
661
662# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
663# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
664# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
665# and from include/config/auto.conf.cmd to detect the compiler upgrade.
666CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
667
668ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
669include $(srctree)/scripts/Makefile.clang
670endif
671
672# Include this also for config targets because some architectures need
673# cc-cross-prefix to determine CROSS_COMPILE.
674ifdef need-compiler
675include $(srctree)/scripts/Makefile.compiler
676endif
677
678ifdef config-build
679# ===========================================================================
680# *config targets only - make sure prerequisites are updated, and descend
681# in scripts/kconfig to make the *config target
682
683# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
684# KBUILD_DEFCONFIG may point out an alternative default configuration
685# used for 'make defconfig'
686include $(srctree)/arch/$(SRCARCH)/Makefile
687export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
688
689config: outputmakefile scripts_basic FORCE
690	$(Q)$(MAKE) $(build)=scripts/kconfig $@
691
692%config: outputmakefile scripts_basic FORCE
693	$(Q)$(MAKE) $(build)=scripts/kconfig $@
694
695else #!config-build
696# ===========================================================================
697# Build targets only - this includes vmlinux, arch specific targets, clean
698# targets and others. In general all targets except *config targets.
699
700# If building an external module we do not care about the all: rule
701# but instead __all depend on modules
702PHONY += all
703ifeq ($(KBUILD_EXTMOD),)
704__all: all
705else
706__all: modules
707endif
708
709targets :=
710
711# Decide whether to build built-in, modular, or both.
712# Normally, just do built-in.
713
714KBUILD_MODULES :=
715KBUILD_BUILTIN := 1
716
717# If we have only "make modules", don't compile built-in objects.
718ifeq ($(MAKECMDGOALS),modules)
719  KBUILD_BUILTIN :=
720endif
721
722# If we have "make <whatever> modules", compile modules
723# in addition to whatever we do anyway.
724# Just "make" or "make all" shall build modules as well
725
726ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
727  KBUILD_MODULES := 1
728endif
729
730ifeq ($(MAKECMDGOALS),)
731  KBUILD_MODULES := 1
732endif
733
734export KBUILD_MODULES KBUILD_BUILTIN
735
736ifdef need-config
737include include/config/auto.conf
738endif
739
740ifeq ($(KBUILD_EXTMOD),)
741# Objects we will link into vmlinux / subdirs we need to visit
742core-y		:=
743drivers-y	:=
744libs-y		:= lib/
745endif # KBUILD_EXTMOD
746
747# The all: target is the default when no target is given on the
748# command line.
749# This allow a user to issue only 'make' to build a kernel including modules
750# Defaults to vmlinux, but the arch makefile usually adds further targets
751all: vmlinux
752
753CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
754ifdef CONFIG_CC_IS_GCC
755CFLAGS_GCOV	+= -fno-tree-loop-im
756endif
757export CFLAGS_GCOV
758
759# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
760ifdef CONFIG_FUNCTION_TRACER
761  CC_FLAGS_FTRACE := -pg
762endif
763
764include $(srctree)/arch/$(SRCARCH)/Makefile
765
766ifdef need-config
767ifdef may-sync-config
768# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
769# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
770# because some architectures define CROSS_COMPILE there.
771include include/config/auto.conf.cmd
772
773$(KCONFIG_CONFIG):
774	@echo >&2 '***'
775	@echo >&2 '*** Configuration file "$@" not found!'
776	@echo >&2 '***'
777	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
778	@echo >&2 '*** "make menuconfig" or "make xconfig").'
779	@echo >&2 '***'
780	@/bin/false
781
782# The actual configuration files used during the build are stored in
783# include/generated/ and include/config/. Update them if .config is newer than
784# include/config/auto.conf (which mirrors .config).
785#
786# This exploits the 'multi-target pattern rule' trick.
787# The syncconfig should be executed only once to make all the targets.
788# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
789#
790# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
791# so you cannot notice that Kconfig is waiting for the user input.
792%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
793	$(Q)$(kecho) "  SYNC    $@"
794	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
795else # !may-sync-config
796# External modules and some install targets need include/generated/autoconf.h
797# and include/config/auto.conf but do not care if they are up-to-date.
798# Use auto.conf to trigger the test
799PHONY += include/config/auto.conf
800
801include/config/auto.conf:
802	@test -e include/generated/autoconf.h -a -e $@ || (		\
803	echo >&2;							\
804	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
805	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
806	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
807	echo >&2 ;							\
808	/bin/false)
809
810endif # may-sync-config
811endif # need-config
812
813KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
814KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
815KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
816KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
817KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
818
819ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
820KBUILD_CFLAGS += -O2
821KBUILD_RUSTFLAGS += -Copt-level=2
822else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
823KBUILD_CFLAGS += -Os
824KBUILD_RUSTFLAGS += -Copt-level=s
825endif
826
827# Always set `debug-assertions` and `overflow-checks` because their default
828# depends on `opt-level` and `debug-assertions`, respectively.
829KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
830KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
831
832# Tell gcc to never replace conditional load with a non-conditional one
833ifdef CONFIG_CC_IS_GCC
834# gcc-10 renamed --param=allow-store-data-races=0 to
835# -fno-allow-store-data-races.
836KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
837KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
838endif
839
840ifdef CONFIG_READABLE_ASM
841# Disable optimizations that make assembler listings hard to read.
842# reorder blocks reorders the control in the function
843# ipa clone creates specialized cloned functions
844# partial inlining inlines only parts of functions
845KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
846endif
847
848ifneq ($(CONFIG_FRAME_WARN),0)
849KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
850endif
851
852stackp-flags-y                                    := -fno-stack-protector
853stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
854stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
855
856KBUILD_CFLAGS += $(stackp-flags-y)
857
858KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror
859KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y)
860KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
861
862KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
863KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
864
865ifdef CONFIG_CC_IS_CLANG
866# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
867KBUILD_CFLAGS += -Wno-gnu
868else
869
870# gcc inanely warns about local variables called 'main'
871KBUILD_CFLAGS += -Wno-main
872endif
873
874# These warnings generated too much noise in a regular build.
875# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
876KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
877KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
878
879# These result in bogus false positives
880KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
881
882ifdef CONFIG_FRAME_POINTER
883KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
884KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
885else
886# Some targets (ARM with Thumb2, for example), can't be built with frame
887# pointers.  For those, we don't have FUNCTION_TRACER automatically
888# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
889# incompatible with -fomit-frame-pointer with current GCC, so we don't use
890# -fomit-frame-pointer with FUNCTION_TRACER.
891# In the Rust target specification, "frame-pointer" is set explicitly
892# to "may-omit".
893ifndef CONFIG_FUNCTION_TRACER
894KBUILD_CFLAGS	+= -fomit-frame-pointer
895endif
896endif
897
898# Initialize all stack variables with a 0xAA pattern.
899ifdef CONFIG_INIT_STACK_ALL_PATTERN
900KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
901endif
902
903# Initialize all stack variables with a zero value.
904ifdef CONFIG_INIT_STACK_ALL_ZERO
905KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
906ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
907# https://github.com/llvm/llvm-project/issues/44842
908CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
909export CC_AUTO_VAR_INIT_ZERO_ENABLER
910KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
911endif
912endif
913
914# While VLAs have been removed, GCC produces unreachable stack probes
915# for the randomize_kstack_offset feature. Disable it for all compilers.
916KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
917
918# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
919ifdef CONFIG_ZERO_CALL_USED_REGS
920KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
921endif
922
923ifdef CONFIG_FUNCTION_TRACER
924ifdef CONFIG_FTRACE_MCOUNT_USE_CC
925  CC_FLAGS_FTRACE	+= -mrecord-mcount
926  ifdef CONFIG_HAVE_NOP_MCOUNT
927    ifeq ($(call cc-option-yn, -mnop-mcount),y)
928      CC_FLAGS_FTRACE	+= -mnop-mcount
929      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
930    endif
931  endif
932endif
933ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
934  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
935    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
936  endif
937endif
938ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
939  ifdef CONFIG_HAVE_C_RECORDMCOUNT
940    BUILD_C_RECORDMCOUNT := y
941    export BUILD_C_RECORDMCOUNT
942  endif
943endif
944ifdef CONFIG_HAVE_FENTRY
945  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
946  ifeq ($(call cc-option-yn, -mfentry),y)
947    CC_FLAGS_FTRACE	+= -mfentry
948    CC_FLAGS_USING	+= -DCC_USING_FENTRY
949  endif
950endif
951export CC_FLAGS_FTRACE
952KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
953KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
954endif
955
956# We trigger additional mismatches with less inlining
957ifdef CONFIG_DEBUG_SECTION_MISMATCH
958KBUILD_CFLAGS += -fno-inline-functions-called-once
959endif
960
961# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
962ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
963KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
964KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
965LDFLAGS_vmlinux += --gc-sections
966endif
967
968ifdef CONFIG_SHADOW_CALL_STACK
969ifndef CONFIG_DYNAMIC_SCS
970CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
971KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
972endif
973export CC_FLAGS_SCS
974endif
975
976ifdef CONFIG_LTO_CLANG
977ifdef CONFIG_LTO_CLANG_THIN
978CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
979KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
980else
981CC_FLAGS_LTO	:= -flto
982endif
983CC_FLAGS_LTO	+= -fvisibility=hidden
984
985# Limit inlining across translation units to reduce binary size
986KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
987
988# Check for frame size exceeding threshold during prolog/epilog insertion
989# when using lld < 13.0.0.
990ifneq ($(CONFIG_FRAME_WARN),0)
991ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
992KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
993endif
994endif
995endif
996
997ifdef CONFIG_LTO
998KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
999KBUILD_AFLAGS	+= -fno-lto
1000export CC_FLAGS_LTO
1001endif
1002
1003ifdef CONFIG_CFI_CLANG
1004CC_FLAGS_CFI	:= -fsanitize=kcfi
1005KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1006export CC_FLAGS_CFI
1007endif
1008
1009ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1010KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1011endif
1012
1013# arch Makefile may override CC so keep this after arch Makefile is included
1014NOSTDINC_FLAGS += -nostdinc
1015
1016# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
1017KBUILD_CFLAGS += -Wvla
1018
1019# disable pointer signed / unsigned warnings in gcc 4.0
1020KBUILD_CFLAGS += -Wno-pointer-sign
1021
1022# In order to make sure new function cast mismatches are not introduced
1023# in the kernel (to avoid tripping CFI checking), the kernel should be
1024# globally built with -Wcast-function-type.
1025KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
1026
1027# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
1028# the kernel uses only C99 flexible arrays for dynamically sized trailing
1029# arrays. Enforce this for everything that may examine structure sizes and
1030# perform bounds checking.
1031KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
1032
1033# disable stringop warnings in gcc 8+
1034KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1035
1036# We'll want to enable this eventually, but it's not going away for 5.7 at least
1037KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1038
1039# Another good warning that we'll want to enable eventually
1040KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1041
1042# Enabled with W=2, disabled by default as noisy
1043ifdef CONFIG_CC_IS_GCC
1044KBUILD_CFLAGS += -Wno-maybe-uninitialized
1045endif
1046
1047# The allocators already balk at large sizes, so silence the compiler
1048# warnings for bounds checks involving those possible values. While
1049# -Wno-alloc-size-larger-than would normally be used here, earlier versions
1050# of gcc (<9.1) weirdly don't handle the option correctly when _other_
1051# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
1052# doesn't work (as it is documented to), silently resolving to "0" prior to
1053# version 9.1 (and producing an error more recently). Numeric values larger
1054# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
1055# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
1056# choice, we must perform a versioned check to disable this warning.
1057# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
1058KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
1059KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
1060
1061# disable invalid "can't wrap" optimizations for signed / pointers
1062KBUILD_CFLAGS	+= -fno-strict-overflow
1063
1064# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1065KBUILD_CFLAGS  += -fno-stack-check
1066
1067# conserve stack if available
1068ifdef CONFIG_CC_IS_GCC
1069KBUILD_CFLAGS   += -fconserve-stack
1070endif
1071
1072# Prohibit date/time macros, which would make the build non-deterministic
1073KBUILD_CFLAGS   += -Werror=date-time
1074
1075# enforce correct pointer usage
1076KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1077
1078# Require designated initializers for all marked structures
1079KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1080
1081# change __FILE__ to the relative path from the srctree
1082KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1083
1084# include additional Makefiles when needed
1085include-y			:= scripts/Makefile.extrawarn
1086include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1087include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1088include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1089include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1090include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1091include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1092include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1093include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1094
1095include $(addprefix $(srctree)/, $(include-y))
1096
1097# scripts/Makefile.gcc-plugins is intentionally included last.
1098# Do not add $(call cc-option,...) below this line. When you build the kernel
1099# from the clean source tree, the GCC plugins do not exist at this point.
1100
1101# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1102KBUILD_CPPFLAGS += $(KCPPFLAGS)
1103KBUILD_AFLAGS   += $(KAFLAGS)
1104KBUILD_CFLAGS   += $(KCFLAGS)
1105KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1106
1107KBUILD_LDFLAGS_MODULE += --build-id=sha1
1108LDFLAGS_vmlinux += --build-id=sha1
1109
1110KBUILD_LDFLAGS	+= -z noexecstack
1111ifeq ($(CONFIG_LD_IS_BFD),y)
1112KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1113endif
1114
1115ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1116LDFLAGS_vmlinux	+= -X
1117endif
1118
1119ifeq ($(CONFIG_RELR),y)
1120# ld.lld before 15 did not support -z pack-relative-relocs.
1121LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1122endif
1123
1124# We never want expected sections to be placed heuristically by the
1125# linker. All sections should be explicitly named in the linker script.
1126ifdef CONFIG_LD_ORPHAN_WARN
1127LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1128endif
1129
1130# Align the bit size of userspace programs with the kernel
1131KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1132KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1133
1134# make the checker run with the right architecture
1135CHECKFLAGS += --arch=$(ARCH)
1136
1137# insure the checker run with the right endianness
1138CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1139
1140# the checker needs the correct machine size
1141CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1142
1143# Default kernel image to build when no specific target is given.
1144# KBUILD_IMAGE may be overruled on the command line or
1145# set in the environment
1146# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1147# this default value
1148export KBUILD_IMAGE ?= vmlinux
1149
1150#
1151# INSTALL_PATH specifies where to place the updated kernel and system map
1152# images. Default is /boot, but you can set it to other values
1153export	INSTALL_PATH ?= /boot
1154
1155#
1156# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1157# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1158# an argument if needed. Otherwise it defaults to the kernel install path
1159#
1160export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1161
1162#
1163# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1164# relocations required by build roots.  This is not defined in the
1165# makefile but the argument can be passed to make if needed.
1166#
1167
1168MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1169export MODLIB
1170
1171PHONY += prepare0
1172
1173export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1174export MODORDER := $(extmod_prefix)modules.order
1175export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1176
1177ifeq ($(KBUILD_EXTMOD),)
1178
1179build-dir	:= .
1180clean-dirs	:= $(sort . Documentation \
1181		     $(patsubst %/,%,$(filter %/, $(core-) \
1182			$(drivers-) $(libs-))))
1183
1184export ARCH_CORE	:= $(core-y)
1185export ARCH_LIB		:= $(filter %/, $(libs-y))
1186export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1187# Externally visible symbols (used by link-vmlinux.sh)
1188
1189KBUILD_VMLINUX_OBJS := ./built-in.a
1190ifdef CONFIG_MODULES
1191KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1192KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1193else
1194KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1195endif
1196
1197export KBUILD_VMLINUX_LIBS
1198export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1199
1200ifdef CONFIG_TRIM_UNUSED_KSYMS
1201# For the kernel to actually contain only the needed exported symbols,
1202# we have to build modules as well to determine what those symbols are.
1203KBUILD_MODULES := 1
1204endif
1205
1206# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1207quiet_cmd_ar_vmlinux.a = AR      $@
1208      cmd_ar_vmlinux.a = \
1209	rm -f $@; \
1210	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1211	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1212
1213targets += vmlinux.a
1214vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1215	$(call if_changed,ar_vmlinux.a)
1216
1217PHONY += vmlinux_o
1218vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1219	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1220
1221vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1222	@:
1223
1224PHONY += vmlinux
1225# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1226# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1227# unrelated; the decompressors just happen to have the same base name,
1228# arch/*/boot/compressed/vmlinux.
1229# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1230#
1231# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1232#   https://savannah.gnu.org/bugs/?61463
1233# For Make > 4.4, the following simple code will work:
1234#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1235vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1236vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1237vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1238	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1239
1240# The actual objects are generated when descending,
1241# make sure no implicit rule kicks in
1242$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1243
1244ifeq ($(origin KERNELRELEASE),file)
1245filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1246else
1247filechk_kernel.release = echo $(KERNELRELEASE)
1248endif
1249
1250# Store (new) KERNELRELEASE string in include/config/kernel.release
1251include/config/kernel.release: FORCE
1252	$(call filechk,kernel.release)
1253
1254# Additional helpers built in scripts/
1255# Carefully list dependencies so we do not try to build scripts twice
1256# in parallel
1257PHONY += scripts
1258scripts: scripts_basic scripts_dtc
1259	$(Q)$(MAKE) $(build)=$(@)
1260
1261# Things we need to do before we recursively start building the kernel
1262# or the modules are listed in "prepare".
1263# A multi level approach is used. prepareN is processed before prepareN-1.
1264# archprepare is used in arch Makefiles and when processed asm symlink,
1265# version.h and scripts_basic is processed / created.
1266
1267PHONY += prepare archprepare
1268
1269archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1270	asm-generic $(version_h) include/generated/utsrelease.h \
1271	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1272
1273prepare0: archprepare
1274	$(Q)$(MAKE) $(build)=scripts/mod
1275	$(Q)$(MAKE) $(build)=. prepare
1276
1277# All the preparing..
1278prepare: prepare0
1279ifdef CONFIG_RUST
1280	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v
1281	$(Q)$(MAKE) $(build)=rust
1282endif
1283
1284PHONY += remove-stale-files
1285remove-stale-files:
1286	$(Q)$(srctree)/scripts/remove-stale-files
1287
1288# Support for using generic headers in asm-generic
1289asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1290
1291PHONY += asm-generic uapi-asm-generic
1292asm-generic: uapi-asm-generic
1293	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1294	generic=include/asm-generic
1295uapi-asm-generic:
1296	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1297	generic=include/uapi/asm-generic
1298
1299# Generate some files
1300# ---------------------------------------------------------------------------
1301
1302# KERNELRELEASE can change from a few different places, meaning version.h
1303# needs to be updated, so this check is forced on all builds
1304
1305uts_len := 64
1306define filechk_utsrelease.h
1307	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1308	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1309	  exit 1;                                                         \
1310	fi;                                                               \
1311	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1312endef
1313
1314define filechk_version.h
1315	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1316		echo \#define LINUX_VERSION_CODE $(shell                 \
1317		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1318	else                                                             \
1319		echo \#define LINUX_VERSION_CODE $(shell                 \
1320		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1321	fi;                                                              \
1322	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1323	((c) > 255 ? 255 : (c)))';                                       \
1324	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1325	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1326	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1327endef
1328
1329$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1330$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1331$(version_h): FORCE
1332	$(call filechk,version.h)
1333
1334include/generated/utsrelease.h: include/config/kernel.release FORCE
1335	$(call filechk,utsrelease.h)
1336
1337filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1338	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1339
1340include/generated/compile.h: FORCE
1341	$(call filechk,compile.h)
1342
1343PHONY += headerdep
1344headerdep:
1345	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1346	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1347
1348# ---------------------------------------------------------------------------
1349# Kernel headers
1350
1351#Default location for installed headers
1352export INSTALL_HDR_PATH = $(objtree)/usr
1353
1354quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1355      cmd_headers_install = \
1356	mkdir -p $(INSTALL_HDR_PATH); \
1357	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1358	usr/include $(INSTALL_HDR_PATH)
1359
1360PHONY += headers_install
1361headers_install: headers
1362	$(call cmd,headers_install)
1363
1364PHONY += archheaders archscripts
1365
1366hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1367
1368PHONY += headers
1369headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1370	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1371	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1372	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1373
1374ifdef CONFIG_HEADERS_INSTALL
1375prepare: headers
1376endif
1377
1378PHONY += scripts_unifdef
1379scripts_unifdef: scripts_basic
1380	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1381
1382# ---------------------------------------------------------------------------
1383# Install
1384
1385# Many distributions have the custom install script, /sbin/installkernel.
1386# If DKMS is installed, 'make install' will eventually recurse back
1387# to this Makefile to build and install external modules.
1388# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1389
1390quiet_cmd_install = INSTALL $(INSTALL_PATH)
1391      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1392
1393# ---------------------------------------------------------------------------
1394# Tools
1395
1396ifdef CONFIG_OBJTOOL
1397prepare: tools/objtool
1398endif
1399
1400ifdef CONFIG_BPF
1401ifdef CONFIG_DEBUG_INFO_BTF
1402prepare: tools/bpf/resolve_btfids
1403endif
1404endif
1405
1406PHONY += resolve_btfids_clean
1407
1408resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1409
1410# tools/bpf/resolve_btfids directory might not exist
1411# in output directory, skip its clean in that case
1412resolve_btfids_clean:
1413ifneq ($(wildcard $(resolve_btfids_O)),)
1414	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1415endif
1416
1417# Clear a bunch of variables before executing the submake
1418ifeq ($(quiet),silent_)
1419tools_silent=s
1420endif
1421
1422tools/: FORCE
1423	$(Q)mkdir -p $(objtree)/tools
1424	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1425
1426tools/%: FORCE
1427	$(Q)mkdir -p $(objtree)/tools
1428	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1429
1430# ---------------------------------------------------------------------------
1431# Kernel selftest
1432
1433PHONY += kselftest
1434kselftest: headers
1435	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1436
1437kselftest-%: headers FORCE
1438	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1439
1440PHONY += kselftest-merge
1441kselftest-merge:
1442	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1443	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1444		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1445	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1446
1447# ---------------------------------------------------------------------------
1448# Devicetree files
1449
1450ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1451dtstree := arch/$(SRCARCH)/boot/dts
1452endif
1453
1454ifneq ($(dtstree),)
1455
1456%.dtb: dtbs_prepare
1457	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1458
1459%.dtbo: dtbs_prepare
1460	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1461
1462PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1463dtbs: dtbs_prepare
1464	$(Q)$(MAKE) $(build)=$(dtstree)
1465
1466# include/config/kernel.release is actually needed when installing DTBs because
1467# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1468# dtbs_install depend on it as dtbs_install may run as root.
1469dtbs_prepare: include/config/kernel.release scripts_dtc
1470
1471ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1472export CHECK_DTBS=y
1473endif
1474
1475ifneq ($(CHECK_DTBS),)
1476dtbs_prepare: dt_binding_check
1477endif
1478
1479dtbs_check: dtbs
1480
1481dtbs_install:
1482	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1483
1484ifdef CONFIG_OF_EARLY_FLATTREE
1485all: dtbs
1486endif
1487
1488endif
1489
1490PHONY += scripts_dtc
1491scripts_dtc: scripts_basic
1492	$(Q)$(MAKE) $(build)=scripts/dtc
1493
1494ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1495export CHECK_DT_BINDING=y
1496endif
1497
1498PHONY += dt_binding_check
1499dt_binding_check: scripts_dtc
1500	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1501
1502PHONY += dt_compatible_check
1503dt_compatible_check: dt_binding_check
1504	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1505
1506# ---------------------------------------------------------------------------
1507# Modules
1508
1509ifdef CONFIG_MODULES
1510
1511# By default, build modules as well
1512
1513all: modules
1514
1515# When we're building modules with modversions, we need to consider
1516# the built-in objects during the descend as well, in order to
1517# make sure the checksums are up to date before we record them.
1518ifdef CONFIG_MODVERSIONS
1519  KBUILD_BUILTIN := 1
1520endif
1521
1522# Build modules
1523#
1524
1525# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1526# is an exception.
1527ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1528KBUILD_BUILTIN := 1
1529modules: vmlinux
1530endif
1531
1532modules: modules_prepare
1533
1534# Target to prepare building external modules
1535modules_prepare: prepare
1536	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1537
1538export modules_sign_only :=
1539
1540ifeq ($(CONFIG_MODULE_SIG),y)
1541PHONY += modules_sign
1542modules_sign: modules_install
1543	@:
1544
1545# modules_sign is a subset of modules_install.
1546# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1547ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1548modules_sign_only := y
1549endif
1550endif
1551
1552endif # CONFIG_MODULES
1553
1554modinst_pre :=
1555ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1556modinst_pre := __modinst_pre
1557endif
1558
1559modules_install: $(modinst_pre)
1560PHONY += __modinst_pre
1561__modinst_pre:
1562	@rm -rf $(MODLIB)/kernel
1563	@rm -f $(MODLIB)/source
1564	@mkdir -p $(MODLIB)
1565ifdef CONFIG_MODULES
1566	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1567	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1568		rm -f $(MODLIB)/build ; \
1569		ln -s $(CURDIR) $(MODLIB)/build ; \
1570	fi
1571	@sed 's:^\(.*\)\.o$$:kernel/\1.ko:' modules.order > $(MODLIB)/modules.order
1572endif
1573	@cp -f modules.builtin $(MODLIB)/
1574	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1575
1576###
1577# Cleaning is done on three levels.
1578# make clean     Delete most generated files
1579#                Leave enough to build external modules
1580# make mrproper  Delete the current configuration, and all generated files
1581# make distclean Remove editor backup files, patch leftover files and the like
1582
1583# Directories & files removed with 'make clean'
1584CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1585	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1586	       compile_commands.json .thinlto-cache rust/test rust/doc \
1587	       rust-project.json .vmlinux.objs .vmlinux.export.c
1588
1589# Directories & files removed with 'make mrproper'
1590MRPROPER_FILES += include/config include/generated          \
1591		  arch/$(SRCARCH)/include/generated .objdiff \
1592		  debian snap tar-install \
1593		  .config .config.old .version \
1594		  Module.symvers \
1595		  certs/signing_key.pem \
1596		  certs/x509.genkey \
1597		  vmlinux-gdb.py \
1598		  *.spec rpmbuild \
1599		  rust/libmacros.so
1600
1601# clean - Delete most, but leave enough to build external modules
1602#
1603clean: rm-files := $(CLEAN_FILES)
1604
1605PHONY += archclean vmlinuxclean
1606
1607vmlinuxclean:
1608	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1609	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1610
1611clean: archclean vmlinuxclean resolve_btfids_clean
1612
1613# mrproper - Delete all generated files, including .config
1614#
1615mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1616mrproper-dirs      := $(addprefix _mrproper_,scripts)
1617
1618PHONY += $(mrproper-dirs) mrproper
1619$(mrproper-dirs):
1620	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1621
1622mrproper: clean $(mrproper-dirs)
1623	$(call cmd,rmfiles)
1624	@find . $(RCS_FIND_IGNORE) \
1625		\( -name '*.rmeta' \) \
1626		-type f -print | xargs rm -f
1627
1628# distclean
1629#
1630PHONY += distclean
1631
1632distclean: mrproper
1633	@find . $(RCS_FIND_IGNORE) \
1634		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1635		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1636		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1637		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1638		-type f -print | xargs rm -f
1639
1640
1641# Packaging of the kernel to various formats
1642# ---------------------------------------------------------------------------
1643
1644%src-pkg: FORCE
1645	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1646%pkg: include/config/kernel.release FORCE
1647	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1648
1649# Brief documentation of the typical targets used
1650# ---------------------------------------------------------------------------
1651
1652boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1653boards := $(sort $(notdir $(boards)))
1654board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1655board-dirs := $(sort $(notdir $(board-dirs:/=)))
1656
1657PHONY += help
1658help:
1659	@echo  'Cleaning targets:'
1660	@echo  '  clean		  - Remove most generated files but keep the config and'
1661	@echo  '                    enough build support to build external modules'
1662	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1663	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1664	@echo  ''
1665	@echo  'Configuration targets:'
1666	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1667	@echo  ''
1668	@echo  'Other generic targets:'
1669	@echo  '  all		  - Build all targets marked with [*]'
1670	@echo  '* vmlinux	  - Build the bare kernel'
1671	@echo  '* modules	  - Build all modules'
1672	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1673	@echo  '  dir/            - Build all files in dir and below'
1674	@echo  '  dir/file.[ois]  - Build specified target only'
1675	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1676	@echo  '                    (requires compiler support for LLVM assembly generation)'
1677	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1678	@echo  '                    (requires a recent binutils and recent build (System.map))'
1679	@echo  '  dir/file.ko     - Build module including final link'
1680	@echo  '  modules_prepare - Set up for building external modules'
1681	@echo  '  tags/TAGS	  - Generate tags file for editors'
1682	@echo  '  cscope	  - Generate cscope index'
1683	@echo  '  gtags           - Generate GNU GLOBAL index'
1684	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1685	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1686	@echo  '  image_name	  - Output the image name (use with make -s)'
1687	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1688	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1689	 echo  ''
1690	@echo  'Static analysers:'
1691	@echo  '  checkstack      - Generate a list of stack hogs'
1692	@echo  '  versioncheck    - Sanity check on version.h usage'
1693	@echo  '  includecheck    - Check for duplicate included header files'
1694	@echo  '  export_report   - List the usages of all exported symbols'
1695	@echo  '  headerdep       - Detect inclusion cycles in headers'
1696	@echo  '  coccicheck      - Check with Coccinelle'
1697	@echo  '  clang-analyzer  - Check with clang static analyzer'
1698	@echo  '  clang-tidy      - Check with clang-tidy'
1699	@echo  ''
1700	@echo  'Tools:'
1701	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1702	@echo  ''
1703	@echo  'Kernel selftest:'
1704	@echo  '  kselftest         - Build and run kernel selftest'
1705	@echo  '                      Build, install, and boot kernel before'
1706	@echo  '                      running kselftest on it'
1707	@echo  '                      Run as root for full coverage'
1708	@echo  '  kselftest-all     - Build kernel selftest'
1709	@echo  '  kselftest-install - Build and install kernel selftest'
1710	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1711	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1712	@echo  '		      kselftest to existing .config.'
1713	@echo  ''
1714	@echo  'Rust targets:'
1715	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1716	@echo  '		    available and, if not, explains why.'
1717	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1718	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1719	@echo  '		    is formatted, printing a diff otherwise.'
1720	@echo  '  rustdoc	  - Generate Rust documentation'
1721	@echo  '		    (requires kernel .config)'
1722	@echo  '  rusttest        - Runs the Rust tests'
1723	@echo  '                    (requires kernel .config; downloads external repos)'
1724	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1725	@echo  '		    (requires kernel .config)'
1726	@echo  '  dir/file.[os]   - Build specified target only'
1727	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1728	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1729	@echo  '                    The output is not intended to be compilable.'
1730	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1731	@echo  ''
1732	@$(if $(dtstree), \
1733		echo 'Devicetree:'; \
1734		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1735		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1736		echo '  dt_binding_check - Validate device tree binding documents'; \
1737		echo '  dtbs_check       - Validate device tree source files';\
1738		echo '')
1739
1740	@echo 'Userspace tools targets:'
1741	@echo '  use "make tools/help"'
1742	@echo '  or  "cd tools; make help"'
1743	@echo  ''
1744	@echo  'Kernel packaging:'
1745	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1746	@echo  ''
1747	@echo  'Documentation targets:'
1748	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1749	@echo  ''
1750	@echo  'Architecture specific targets ($(SRCARCH)):'
1751	@$(or $(archhelp),\
1752		echo '  No architecture specific help defined for $(SRCARCH)')
1753	@echo  ''
1754	@$(if $(boards), \
1755		$(foreach b, $(boards), \
1756		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1757		echo '')
1758	@$(if $(board-dirs), \
1759		$(foreach b, $(board-dirs), \
1760		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1761		printf "  %-16s - Show all of the above\\n" help-boards; \
1762		echo '')
1763
1764	@echo  '  make V=n   [targets] 1: verbose build'
1765	@echo  '                       2: give reason for rebuild of target'
1766	@echo  '                       V=1 and V=2 can be combined with V=12'
1767	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1768	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1769	@echo  '                       (sparse by default)'
1770	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1771	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1772	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1773	@echo  '		1: warnings which may be relevant and do not occur too often'
1774	@echo  '		2: warnings which occur quite often but may still be relevant'
1775	@echo  '		3: more obscure warnings, can most likely be ignored'
1776	@echo  '		e: warnings are being treated as errors'
1777	@echo  '		Multiple levels can be combined with W=12 or W=123'
1778	@$(if $(dtstree), \
1779		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1780		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1781		)
1782	@echo  ''
1783	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1784	@echo  'For further info see the ./README file'
1785
1786
1787help-board-dirs := $(addprefix help-,$(board-dirs))
1788
1789help-boards: $(help-board-dirs)
1790
1791boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1792
1793$(help-board-dirs): help-%:
1794	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1795	@$(if $(boards-per-dir), \
1796		$(foreach b, $(boards-per-dir), \
1797		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1798		echo '')
1799
1800
1801# Documentation targets
1802# ---------------------------------------------------------------------------
1803DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1804	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1805PHONY += $(DOC_TARGETS)
1806$(DOC_TARGETS):
1807	$(Q)$(MAKE) $(build)=Documentation $@
1808
1809
1810# Rust targets
1811# ---------------------------------------------------------------------------
1812
1813# "Is Rust available?" target
1814PHONY += rustavailable
1815rustavailable:
1816	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v && echo "Rust is available!"
1817
1818# Documentation target
1819#
1820# Using the singular to avoid running afoul of `no-dot-config-targets`.
1821PHONY += rustdoc
1822rustdoc: prepare
1823	$(Q)$(MAKE) $(build)=rust $@
1824
1825# Testing target
1826PHONY += rusttest
1827rusttest: prepare
1828	$(Q)$(MAKE) $(build)=rust $@
1829
1830# Formatting targets
1831PHONY += rustfmt rustfmtcheck
1832
1833# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1834#
1835# We match using absolute paths since `find` does not resolve them
1836# when matching, which is a problem when e.g. `srctree` is `..`.
1837# We `grep` afterwards in order to remove the directory entry itself.
1838rustfmt:
1839	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1840		-o -path $(abs_srctree)/rust/alloc -prune \
1841		-o -path $(abs_objtree)/rust/test -prune \
1842		| grep -Fv $(abs_srctree)/rust/alloc \
1843		| grep -Fv $(abs_objtree)/rust/test \
1844		| grep -Fv generated \
1845		| xargs $(RUSTFMT) $(rustfmt_flags)
1846
1847rustfmtcheck: rustfmt_flags = --check
1848rustfmtcheck: rustfmt
1849
1850# IDE support targets
1851PHONY += rust-analyzer
1852rust-analyzer:
1853	$(Q)$(MAKE) $(build)=rust $@
1854
1855# Misc
1856# ---------------------------------------------------------------------------
1857
1858PHONY += misc-check
1859misc-check:
1860	$(Q)$(srctree)/scripts/misc-check
1861
1862all: misc-check
1863
1864PHONY += scripts_gdb
1865scripts_gdb: prepare0
1866	$(Q)$(MAKE) $(build)=scripts/gdb
1867	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1868
1869ifdef CONFIG_GDB_SCRIPTS
1870all: scripts_gdb
1871endif
1872
1873else # KBUILD_EXTMOD
1874
1875filechk_kernel.release = echo $(KERNELRELEASE)
1876
1877###
1878# External module support.
1879# When building external modules the kernel used as basis is considered
1880# read-only, and no consistency checks are made and the make
1881# system is not used on the basis kernel. If updates are required
1882# in the basis kernel ordinary make commands (without M=...) must be used.
1883
1884# We are always building only modules.
1885KBUILD_BUILTIN :=
1886KBUILD_MODULES := 1
1887
1888build-dir := $(KBUILD_EXTMOD)
1889
1890compile_commands.json: $(extmod_prefix)compile_commands.json
1891PHONY += compile_commands.json
1892
1893clean-dirs := $(KBUILD_EXTMOD)
1894clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1895	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1896
1897PHONY += prepare
1898# now expand this into a simple variable to reduce the cost of shell evaluations
1899prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1900prepare:
1901	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1902		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1903		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1904		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1905	fi
1906
1907PHONY += help
1908help:
1909	@echo  '  Building external modules.'
1910	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1911	@echo  ''
1912	@echo  '  modules         - default target, build the module(s)'
1913	@echo  '  modules_install - install the module'
1914	@echo  '  clean           - remove generated files in module directory only'
1915	@echo  ''
1916
1917__external_modules_error:
1918	@echo >&2 '***'
1919	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1920	@echo >&2 '*** You cannot build or install external modules.'
1921	@echo >&2 '***'
1922	@false
1923
1924endif # KBUILD_EXTMOD
1925
1926# ---------------------------------------------------------------------------
1927# Modules
1928
1929PHONY += modules modules_install modules_prepare
1930
1931ifdef CONFIG_MODULES
1932
1933$(MODORDER): $(build-dir)
1934	@:
1935
1936# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1937# This is solely useful to speed up test compiles.
1938modules: modpost
1939ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1940	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1941endif
1942
1943PHONY += modules_check
1944modules_check: $(MODORDER)
1945	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1946
1947quiet_cmd_depmod = DEPMOD  $(MODLIB)
1948      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1949                   $(KERNELRELEASE)
1950
1951modules_install:
1952	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1953	$(call cmd,depmod)
1954
1955else # CONFIG_MODULES
1956
1957# Modules not configured
1958# ---------------------------------------------------------------------------
1959
1960PHONY += __external_modules_error
1961
1962modules modules_install: __external_modules_error
1963	@:
1964
1965KBUILD_MODULES :=
1966
1967endif # CONFIG_MODULES
1968
1969PHONY += modpost
1970modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1971	 $(if $(KBUILD_MODULES), modules_check)
1972	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1973
1974# Single targets
1975# ---------------------------------------------------------------------------
1976# To build individual files in subdirectories, you can do like this:
1977#
1978#   make foo/bar/baz.s
1979#
1980# The supported suffixes for single-target are listed in 'single-targets'
1981#
1982# To build only under specific subdirectories, you can do like this:
1983#
1984#   make foo/bar/baz/
1985
1986ifdef single-build
1987
1988# .ko is special because modpost is needed
1989single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1990single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1991		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1992
1993$(single-ko): single_modules
1994	@:
1995$(single-no-ko): $(build-dir)
1996	@:
1997
1998# Remove MODORDER when done because it is not the real one.
1999PHONY += single_modules
2000single_modules: $(single-no-ko) modules_prepare
2001	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
2002	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
2003ifneq ($(KBUILD_MODPOST_NOFINAL),1)
2004	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
2005endif
2006	$(Q)rm -f $(MODORDER)
2007
2008single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
2009
2010KBUILD_MODULES := 1
2011
2012endif
2013
2014# Preset locale variables to speed up the build process. Limit locale
2015# tweaks to this spot to avoid wrong language settings when running
2016# make menuconfig etc.
2017# Error messages still appears in the original language
2018PHONY += $(build-dir)
2019$(build-dir): prepare
2020	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
2021
2022clean-dirs := $(addprefix _clean_, $(clean-dirs))
2023PHONY += $(clean-dirs) clean
2024$(clean-dirs):
2025	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2026
2027clean: $(clean-dirs)
2028	$(call cmd,rmfiles)
2029	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
2030		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2031		-o -name '*.ko.*' \
2032		-o -name '*.dtb' -o -name '*.dtbo' \
2033		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2034		-o -name '*.dt.yaml' \
2035		-o -name '*.dwo' -o -name '*.lst' \
2036		-o -name '*.su' -o -name '*.mod' \
2037		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2038		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2039		-o -name '*.asn1.[ch]' \
2040		-o -name '*.symtypes' -o -name 'modules.order' \
2041		-o -name '*.c.[012]*.*' \
2042		-o -name '*.ll' \
2043		-o -name '*.gcno' \
2044		-o -name '*.*.symversions' \) -type f -print \
2045		-o -name '.tmp_*' -print \
2046		| xargs rm -rf
2047
2048# Generate tags for editors
2049# ---------------------------------------------------------------------------
2050quiet_cmd_tags = GEN     $@
2051      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2052
2053tags TAGS cscope gtags: FORCE
2054	$(call cmd,tags)
2055
2056# Script to generate missing namespace dependencies
2057# ---------------------------------------------------------------------------
2058
2059PHONY += nsdeps
2060nsdeps: export KBUILD_NSDEPS=1
2061nsdeps: modules
2062	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2063
2064# Clang Tooling
2065# ---------------------------------------------------------------------------
2066
2067quiet_cmd_gen_compile_commands = GEN     $@
2068      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2069
2070$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
2071	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2072	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2073	$(call if_changed,gen_compile_commands)
2074
2075targets += $(extmod_prefix)compile_commands.json
2076
2077PHONY += clang-tidy clang-analyzer
2078
2079ifdef CONFIG_CC_IS_CLANG
2080quiet_cmd_clang_tools = CHECK   $<
2081      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2082
2083clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2084	$(call cmd,clang_tools)
2085else
2086clang-tidy clang-analyzer:
2087	@echo "$@ requires CC=clang" >&2
2088	@false
2089endif
2090
2091# Scripts to check various things for consistency
2092# ---------------------------------------------------------------------------
2093
2094PHONY += includecheck versioncheck coccicheck export_report
2095
2096includecheck:
2097	find $(srctree)/* $(RCS_FIND_IGNORE) \
2098		-name '*.[hcS]' -type f -print | sort \
2099		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2100
2101versioncheck:
2102	find $(srctree)/* $(RCS_FIND_IGNORE) \
2103		-name '*.[hcS]' -type f -print | sort \
2104		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2105
2106coccicheck:
2107	$(Q)$(BASH) $(srctree)/scripts/$@
2108
2109export_report:
2110	$(PERL) $(srctree)/scripts/export_report.pl
2111
2112PHONY += checkstack kernelrelease kernelversion image_name
2113
2114# UML needs a little special treatment here.  It wants to use the host
2115# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2116# else wants $(ARCH), including people doing cross-builds, which means
2117# that $(SUBARCH) doesn't work here.
2118ifeq ($(ARCH), um)
2119CHECKSTACK_ARCH := $(SUBARCH)
2120else
2121CHECKSTACK_ARCH := $(ARCH)
2122endif
2123checkstack:
2124	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2125	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2126
2127kernelrelease:
2128	@$(filechk_kernel.release)
2129
2130kernelversion:
2131	@echo $(KERNELVERSION)
2132
2133image_name:
2134	@echo $(KBUILD_IMAGE)
2135
2136quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2137      cmd_rmfiles = rm -rf $(rm-files)
2138
2139# read saved command lines for existing targets
2140existing-targets := $(wildcard $(sort $(targets)))
2141
2142-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2143
2144endif # config-build
2145endif # mixed-build
2146endif # need-sub-make
2147
2148PHONY += FORCE
2149FORCE:
2150
2151# Declare the contents of the PHONY variable as phony.  We keep that
2152# information in a variable so we can use it in if_changed and friends.
2153.PHONY: $(PHONY)
2154