xref: /linux/Makefile (revision 2241f81c91f211b512bd2c3a26a4a74258d0e008)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 7
4SUBLEVEL = 0
5EXTRAVERSION = -rc1
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
280no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
281			  image_name
282single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %.symtypes %/
283
284config-build	:=
285mixed-build	:=
286need-config	:= 1
287may-sync-config	:= 1
288single-build	:=
289
290ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
291	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
292		need-config :=
293	endif
294endif
295
296ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
297	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
298		may-sync-config :=
299	endif
300endif
301
302need-compiler := $(may-sync-config)
303
304ifneq ($(KBUILD_EXTMOD),)
305	may-sync-config :=
306endif
307
308ifeq ($(KBUILD_EXTMOD),)
309        ifneq ($(filter %config,$(MAKECMDGOALS)),)
310		config-build := 1
311                ifneq ($(words $(MAKECMDGOALS)),1)
312			mixed-build := 1
313                endif
314        endif
315endif
316
317# We cannot build single targets and the others at the same time
318ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
319	single-build := 1
320	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
321		mixed-build := 1
322	endif
323endif
324
325# For "make -j clean all", "make -j mrproper defconfig all", etc.
326ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
327        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
328		mixed-build := 1
329        endif
330endif
331
332# install and modules_install need also be processed one by one
333ifneq ($(filter install,$(MAKECMDGOALS)),)
334        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
335		mixed-build := 1
336        endif
337endif
338
339ifdef mixed-build
340# ===========================================================================
341# We're called with mixed targets (*config and build targets).
342# Handle them one by one.
343
344PHONY += $(MAKECMDGOALS) __build_one_by_one
345
346$(MAKECMDGOALS): __build_one_by_one
347	@:
348
349__build_one_by_one:
350	$(Q)set -e; \
351	for i in $(MAKECMDGOALS); do \
352		$(MAKE) -f $(srctree)/Makefile $$i; \
353	done
354
355else # !mixed-build
356
357include $(srctree)/scripts/Kbuild.include
358
359# Read KERNELRELEASE from include/config/kernel.release (if it exists)
360KERNELRELEASE = $(call read-file, include/config/kernel.release)
361KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
362export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
363
364include $(srctree)/scripts/subarch.include
365
366# Cross compiling and selecting different set of gcc/bin-utils
367# ---------------------------------------------------------------------------
368#
369# When performing cross compilation for other architectures ARCH shall be set
370# to the target architecture. (See arch/* for the possibilities).
371# ARCH can be set during invocation of make:
372# make ARCH=arm64
373# Another way is to have ARCH set in the environment.
374# The default ARCH is the host where make is executed.
375
376# CROSS_COMPILE specify the prefix used for all executables used
377# during compilation. Only gcc and related bin-utils executables
378# are prefixed with $(CROSS_COMPILE).
379# CROSS_COMPILE can be set on the command line
380# make CROSS_COMPILE=aarch64-linux-gnu-
381# Alternatively CROSS_COMPILE can be set in the environment.
382# Default value for CROSS_COMPILE is not to prefix executables
383# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
384ARCH		?= $(SUBARCH)
385
386# Architecture as present in compile.h
387UTS_MACHINE 	:= $(ARCH)
388SRCARCH 	:= $(ARCH)
389
390# Additional ARCH settings for x86
391ifeq ($(ARCH),i386)
392        SRCARCH := x86
393endif
394ifeq ($(ARCH),x86_64)
395        SRCARCH := x86
396endif
397
398# Additional ARCH settings for sparc
399ifeq ($(ARCH),sparc32)
400       SRCARCH := sparc
401endif
402ifeq ($(ARCH),sparc64)
403       SRCARCH := sparc
404endif
405
406# Additional ARCH settings for parisc
407ifeq ($(ARCH),parisc64)
408       SRCARCH := parisc
409endif
410
411export cross_compiling :=
412ifneq ($(SRCARCH),$(SUBARCH))
413cross_compiling := 1
414endif
415
416KCONFIG_CONFIG	?= .config
417export KCONFIG_CONFIG
418
419# SHELL used by kbuild
420CONFIG_SHELL := sh
421
422HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
423HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
424HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
425
426ifneq ($(LLVM),)
427ifneq ($(filter %/,$(LLVM)),)
428LLVM_PREFIX := $(LLVM)
429else ifneq ($(filter -%,$(LLVM)),)
430LLVM_SUFFIX := $(LLVM)
431endif
432
433HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
434HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
435else
436HOSTCC	= gcc
437HOSTCXX	= g++
438endif
439HOSTRUSTC = rustc
440HOSTPKG_CONFIG	= pkg-config
441
442KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
443			 -O2 -fomit-frame-pointer -std=gnu11
444KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
445KBUILD_USERLDFLAGS := $(USERLDFLAGS)
446
447# These flags apply to all Rust code in the tree, including the kernel and
448# host programs.
449export rust_common_flags := --edition=2021 \
450			    -Zbinary_dep_depinfo=y \
451			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
452			    -Dunreachable_pub -Dnon_ascii_idents \
453			    -Wmissing_docs \
454			    -Drustdoc::missing_crate_level_docs \
455			    -Dclippy::correctness -Dclippy::style \
456			    -Dclippy::suspicious -Dclippy::complexity \
457			    -Dclippy::perf \
458			    -Dclippy::let_unit_value -Dclippy::mut_mut \
459			    -Dclippy::needless_bitwise_bool \
460			    -Dclippy::needless_continue \
461			    -Dclippy::no_mangle_with_rust_abi \
462			    -Wclippy::dbg_macro
463
464KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
465KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
466KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
467			-Zallow-features= $(HOSTRUSTFLAGS)
468KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
469KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
470
471# Make variables (CC, etc...)
472CPP		= $(CC) -E
473ifneq ($(LLVM),)
474CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
475LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
476AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
477NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
478OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
479OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
480READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
481STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
482else
483CC		= $(CROSS_COMPILE)gcc
484LD		= $(CROSS_COMPILE)ld
485AR		= $(CROSS_COMPILE)ar
486NM		= $(CROSS_COMPILE)nm
487OBJCOPY		= $(CROSS_COMPILE)objcopy
488OBJDUMP		= $(CROSS_COMPILE)objdump
489READELF		= $(CROSS_COMPILE)readelf
490STRIP		= $(CROSS_COMPILE)strip
491endif
492RUSTC		= rustc
493RUSTDOC		= rustdoc
494RUSTFMT		= rustfmt
495CLIPPY_DRIVER	= clippy-driver
496BINDGEN		= bindgen
497CARGO		= cargo
498PAHOLE		= pahole
499RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
500LEX		= flex
501YACC		= bison
502AWK		= awk
503INSTALLKERNEL  := installkernel
504PERL		= perl
505PYTHON3		= python3
506CHECK		= sparse
507BASH		= bash
508KGZIP		= gzip
509KBZIP2		= bzip2
510KLZOP		= lzop
511LZMA		= lzma
512LZ4		= lz4c
513XZ		= xz
514ZSTD		= zstd
515
516CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
517		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
518NOSTDINC_FLAGS :=
519CFLAGS_MODULE   =
520RUSTFLAGS_MODULE =
521AFLAGS_MODULE   =
522LDFLAGS_MODULE  =
523CFLAGS_KERNEL	=
524RUSTFLAGS_KERNEL =
525AFLAGS_KERNEL	=
526LDFLAGS_vmlinux =
527
528# Use USERINCLUDE when you must reference the UAPI directories only.
529USERINCLUDE    := \
530		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
531		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
532		-I$(srctree)/include/uapi \
533		-I$(objtree)/include/generated/uapi \
534                -include $(srctree)/include/linux/compiler-version.h \
535                -include $(srctree)/include/linux/kconfig.h
536
537# Use LINUXINCLUDE when you must reference the include/ directory.
538# Needed to be compatible with the O= option
539LINUXINCLUDE    := \
540		-I$(srctree)/arch/$(SRCARCH)/include \
541		-I$(objtree)/arch/$(SRCARCH)/include/generated \
542		$(if $(building_out_of_srctree),-I$(srctree)/include) \
543		-I$(objtree)/include \
544		$(USERINCLUDE)
545
546KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
547
548KBUILD_CFLAGS :=
549KBUILD_CFLAGS += -std=gnu11
550KBUILD_CFLAGS += -fshort-wchar
551KBUILD_CFLAGS += -funsigned-char
552KBUILD_CFLAGS += -fno-common
553KBUILD_CFLAGS += -fno-PIE
554KBUILD_CFLAGS += -fno-strict-aliasing
555
556KBUILD_CPPFLAGS := -D__KERNEL__
557KBUILD_RUSTFLAGS := $(rust_common_flags) \
558		    --target=$(objtree)/scripts/target.json \
559		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
560		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
561		    -Csymbol-mangling-version=v0 \
562		    -Crelocation-model=static \
563		    -Zfunction-sections=n \
564		    -Dclippy::float_arithmetic
565
566KBUILD_AFLAGS_KERNEL :=
567KBUILD_CFLAGS_KERNEL :=
568KBUILD_RUSTFLAGS_KERNEL :=
569KBUILD_AFLAGS_MODULE  := -DMODULE
570KBUILD_CFLAGS_MODULE  := -DMODULE
571KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
572KBUILD_LDFLAGS_MODULE :=
573KBUILD_LDFLAGS :=
574CLANG_FLAGS :=
575
576ifeq ($(KBUILD_CLIPPY),1)
577	RUSTC_OR_CLIPPY_QUIET := CLIPPY
578	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
579else
580	RUSTC_OR_CLIPPY_QUIET := RUSTC
581	RUSTC_OR_CLIPPY = $(RUSTC)
582endif
583
584ifdef RUST_LIB_SRC
585	export RUST_LIB_SRC
586endif
587
588# Allows the usage of unstable features in stable compilers.
589export RUSTC_BOOTSTRAP := 1
590
591export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
592export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
593export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
594export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
595export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
596export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
597export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
598export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
599
600export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
601export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
602export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
603export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
604export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
605export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
606
607# Files to ignore in find ... statements
608
609export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
610			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
611			  -prune -o
612export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
613			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
614
615# ===========================================================================
616# Rules shared between *config targets and build targets
617
618# Basic helpers built in scripts/basic/
619PHONY += scripts_basic
620scripts_basic:
621	$(Q)$(MAKE) $(build)=scripts/basic
622
623PHONY += outputmakefile
624ifdef building_out_of_srctree
625# Before starting out-of-tree build, make sure the source tree is clean.
626# outputmakefile generates a Makefile in the output directory, if using a
627# separate output directory. This allows convenient use of make in the
628# output directory.
629# At the same time when output Makefile generated, generate .gitignore to
630# ignore whole output directory
631
632quiet_cmd_makefile = GEN     Makefile
633      cmd_makefile = { \
634	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
635	echo "include $(srctree)/Makefile"; \
636	} > Makefile
637
638outputmakefile:
639	@if [ -f $(srctree)/.config -o \
640		 -d $(srctree)/include/config -o \
641		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
642		echo >&2 "***"; \
643		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
644		echo >&2 "*** in $(abs_srctree)";\
645		echo >&2 "***"; \
646		false; \
647	fi
648	$(Q)ln -fsn $(srctree) source
649	$(call cmd,makefile)
650	$(Q)test -e .gitignore || \
651	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
652endif
653
654# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
655# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
656# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
657# and from include/config/auto.conf.cmd to detect the compiler upgrade.
658CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
659
660ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
661include $(srctree)/scripts/Makefile.clang
662endif
663
664# Include this also for config targets because some architectures need
665# cc-cross-prefix to determine CROSS_COMPILE.
666ifdef need-compiler
667include $(srctree)/scripts/Makefile.compiler
668endif
669
670ifdef config-build
671# ===========================================================================
672# *config targets only - make sure prerequisites are updated, and descend
673# in scripts/kconfig to make the *config target
674
675# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
676# KBUILD_DEFCONFIG may point out an alternative default configuration
677# used for 'make defconfig'
678include $(srctree)/arch/$(SRCARCH)/Makefile
679export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
680
681config: outputmakefile scripts_basic FORCE
682	$(Q)$(MAKE) $(build)=scripts/kconfig $@
683
684%config: outputmakefile scripts_basic FORCE
685	$(Q)$(MAKE) $(build)=scripts/kconfig $@
686
687else #!config-build
688# ===========================================================================
689# Build targets only - this includes vmlinux, arch-specific targets, clean
690# targets and others. In general all targets except *config targets.
691
692# If building an external module we do not care about the all: rule
693# but instead __all depend on modules
694PHONY += all
695ifeq ($(KBUILD_EXTMOD),)
696__all: all
697else
698__all: modules
699endif
700
701targets :=
702
703# Decide whether to build built-in, modular, or both.
704# Normally, just do built-in.
705
706KBUILD_MODULES :=
707KBUILD_BUILTIN := 1
708
709# If we have only "make modules", don't compile built-in objects.
710ifeq ($(MAKECMDGOALS),modules)
711  KBUILD_BUILTIN :=
712endif
713
714# If we have "make <whatever> modules", compile modules
715# in addition to whatever we do anyway.
716# Just "make" or "make all" shall build modules as well
717
718ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
719  KBUILD_MODULES := 1
720endif
721
722ifeq ($(MAKECMDGOALS),)
723  KBUILD_MODULES := 1
724endif
725
726export KBUILD_MODULES KBUILD_BUILTIN
727
728ifdef need-config
729include include/config/auto.conf
730endif
731
732ifeq ($(KBUILD_EXTMOD),)
733# Objects we will link into vmlinux / subdirs we need to visit
734core-y		:=
735drivers-y	:=
736libs-y		:= lib/
737endif # KBUILD_EXTMOD
738
739# The all: target is the default when no target is given on the
740# command line.
741# This allow a user to issue only 'make' to build a kernel including modules
742# Defaults to vmlinux, but the arch makefile usually adds further targets
743all: vmlinux
744
745CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
746ifdef CONFIG_CC_IS_GCC
747CFLAGS_GCOV	+= -fno-tree-loop-im
748endif
749export CFLAGS_GCOV
750
751# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
752ifdef CONFIG_FUNCTION_TRACER
753  CC_FLAGS_FTRACE := -pg
754endif
755
756include $(srctree)/arch/$(SRCARCH)/Makefile
757
758ifdef need-config
759ifdef may-sync-config
760# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
761# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
762# because some architectures define CROSS_COMPILE there.
763include include/config/auto.conf.cmd
764
765$(KCONFIG_CONFIG):
766	@echo >&2 '***'
767	@echo >&2 '*** Configuration file "$@" not found!'
768	@echo >&2 '***'
769	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
770	@echo >&2 '*** "make menuconfig" or "make xconfig").'
771	@echo >&2 '***'
772	@/bin/false
773
774# The actual configuration files used during the build are stored in
775# include/generated/ and include/config/. Update them if .config is newer than
776# include/config/auto.conf (which mirrors .config).
777#
778# This exploits the 'multi-target pattern rule' trick.
779# The syncconfig should be executed only once to make all the targets.
780# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
781#
782# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
783# so you cannot notice that Kconfig is waiting for the user input.
784%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
785	$(Q)$(kecho) "  SYNC    $@"
786	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
787else # !may-sync-config
788# External modules and some install targets need include/generated/autoconf.h
789# and include/config/auto.conf but do not care if they are up-to-date.
790# Use auto.conf to trigger the test
791PHONY += include/config/auto.conf
792
793include/config/auto.conf:
794	@test -e include/generated/autoconf.h -a -e $@ || (		\
795	echo >&2;							\
796	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
797	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
798	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
799	echo >&2 ;							\
800	/bin/false)
801
802endif # may-sync-config
803endif # need-config
804
805KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
806
807ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
808KBUILD_CFLAGS += -O2
809KBUILD_RUSTFLAGS += -Copt-level=2
810else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
811KBUILD_CFLAGS += -Os
812KBUILD_RUSTFLAGS += -Copt-level=s
813endif
814
815# Always set `debug-assertions` and `overflow-checks` because their default
816# depends on `opt-level` and `debug-assertions`, respectively.
817KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
818KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
819
820# Tell gcc to never replace conditional load with a non-conditional one
821ifdef CONFIG_CC_IS_GCC
822# gcc-10 renamed --param=allow-store-data-races=0 to
823# -fno-allow-store-data-races.
824KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
825KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
826endif
827
828ifdef CONFIG_READABLE_ASM
829# Disable optimizations that make assembler listings hard to read.
830# reorder blocks reorders the control in the function
831# ipa clone creates specialized cloned functions
832# partial inlining inlines only parts of functions
833KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
834endif
835
836stackp-flags-y                                    := -fno-stack-protector
837stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
838stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
839
840KBUILD_CFLAGS += $(stackp-flags-y)
841
842KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
843KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
844
845ifdef CONFIG_FRAME_POINTER
846KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
847KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
848else
849# Some targets (ARM with Thumb2, for example), can't be built with frame
850# pointers.  For those, we don't have FUNCTION_TRACER automatically
851# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
852# incompatible with -fomit-frame-pointer with current GCC, so we don't use
853# -fomit-frame-pointer with FUNCTION_TRACER.
854# In the Rust target specification, "frame-pointer" is set explicitly
855# to "may-omit".
856ifndef CONFIG_FUNCTION_TRACER
857KBUILD_CFLAGS	+= -fomit-frame-pointer
858endif
859endif
860
861# Initialize all stack variables with a 0xAA pattern.
862ifdef CONFIG_INIT_STACK_ALL_PATTERN
863KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
864endif
865
866# Initialize all stack variables with a zero value.
867ifdef CONFIG_INIT_STACK_ALL_ZERO
868KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
869ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
870# https://github.com/llvm/llvm-project/issues/44842
871CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
872export CC_AUTO_VAR_INIT_ZERO_ENABLER
873KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
874endif
875endif
876
877# While VLAs have been removed, GCC produces unreachable stack probes
878# for the randomize_kstack_offset feature. Disable it for all compilers.
879KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
880
881# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
882ifdef CONFIG_ZERO_CALL_USED_REGS
883KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
884endif
885
886ifdef CONFIG_FUNCTION_TRACER
887ifdef CONFIG_FTRACE_MCOUNT_USE_CC
888  CC_FLAGS_FTRACE	+= -mrecord-mcount
889  ifdef CONFIG_HAVE_NOP_MCOUNT
890    ifeq ($(call cc-option-yn, -mnop-mcount),y)
891      CC_FLAGS_FTRACE	+= -mnop-mcount
892      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
893    endif
894  endif
895endif
896ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
897  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
898    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
899  endif
900endif
901ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
902  ifdef CONFIG_HAVE_C_RECORDMCOUNT
903    BUILD_C_RECORDMCOUNT := y
904    export BUILD_C_RECORDMCOUNT
905  endif
906endif
907ifdef CONFIG_HAVE_FENTRY
908  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
909  ifeq ($(call cc-option-yn, -mfentry),y)
910    CC_FLAGS_FTRACE	+= -mfentry
911    CC_FLAGS_USING	+= -DCC_USING_FENTRY
912  endif
913endif
914export CC_FLAGS_FTRACE
915KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
916KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
917endif
918
919# We trigger additional mismatches with less inlining
920ifdef CONFIG_DEBUG_SECTION_MISMATCH
921KBUILD_CFLAGS += -fno-inline-functions-called-once
922endif
923
924# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
925ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
926KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
927KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
928LDFLAGS_vmlinux += --gc-sections
929endif
930
931ifdef CONFIG_SHADOW_CALL_STACK
932ifndef CONFIG_DYNAMIC_SCS
933CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
934KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
935endif
936export CC_FLAGS_SCS
937endif
938
939ifdef CONFIG_LTO_CLANG
940ifdef CONFIG_LTO_CLANG_THIN
941CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
942KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
943else
944CC_FLAGS_LTO	:= -flto
945endif
946CC_FLAGS_LTO	+= -fvisibility=hidden
947
948# Limit inlining across translation units to reduce binary size
949KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
950
951# Check for frame size exceeding threshold during prolog/epilog insertion
952# when using lld < 13.0.0.
953ifneq ($(CONFIG_FRAME_WARN),0)
954ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
955KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
956endif
957endif
958endif
959
960ifdef CONFIG_LTO
961KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
962KBUILD_AFLAGS	+= -fno-lto
963export CC_FLAGS_LTO
964endif
965
966ifdef CONFIG_CFI_CLANG
967CC_FLAGS_CFI	:= -fsanitize=kcfi
968KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
969export CC_FLAGS_CFI
970endif
971
972ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
973KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
974endif
975
976# arch Makefile may override CC so keep this after arch Makefile is included
977NOSTDINC_FLAGS += -nostdinc
978
979# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
980# the kernel uses only C99 flexible arrays for dynamically sized trailing
981# arrays. Enforce this for everything that may examine structure sizes and
982# perform bounds checking.
983KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
984
985# disable invalid "can't wrap" optimizations for signed / pointers
986KBUILD_CFLAGS	+= -fno-strict-overflow
987
988# Make sure -fstack-check isn't enabled (like gentoo apparently did)
989KBUILD_CFLAGS  += -fno-stack-check
990
991# conserve stack if available
992ifdef CONFIG_CC_IS_GCC
993KBUILD_CFLAGS   += -fconserve-stack
994endif
995
996# change __FILE__ to the relative path from the srctree
997KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
998
999# include additional Makefiles when needed
1000include-y			:= scripts/Makefile.extrawarn
1001include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1002include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1003include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1004include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1005include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1006include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1007include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1008include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1009include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1010
1011include $(addprefix $(srctree)/, $(include-y))
1012
1013# scripts/Makefile.gcc-plugins is intentionally included last.
1014# Do not add $(call cc-option,...) below this line. When you build the kernel
1015# from the clean source tree, the GCC plugins do not exist at this point.
1016
1017# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1018KBUILD_CPPFLAGS += $(KCPPFLAGS)
1019KBUILD_AFLAGS   += $(KAFLAGS)
1020KBUILD_CFLAGS   += $(KCFLAGS)
1021KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1022
1023KBUILD_LDFLAGS_MODULE += --build-id=sha1
1024LDFLAGS_vmlinux += --build-id=sha1
1025
1026KBUILD_LDFLAGS	+= -z noexecstack
1027ifeq ($(CONFIG_LD_IS_BFD),y)
1028KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1029endif
1030
1031ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1032LDFLAGS_vmlinux	+= -X
1033endif
1034
1035ifeq ($(CONFIG_RELR),y)
1036# ld.lld before 15 did not support -z pack-relative-relocs.
1037LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1038endif
1039
1040# We never want expected sections to be placed heuristically by the
1041# linker. All sections should be explicitly named in the linker script.
1042ifdef CONFIG_LD_ORPHAN_WARN
1043LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1044endif
1045
1046# Align the bit size of userspace programs with the kernel
1047KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1048KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1049
1050# make the checker run with the right architecture
1051CHECKFLAGS += --arch=$(ARCH)
1052
1053# insure the checker run with the right endianness
1054CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1055
1056# the checker needs the correct machine size
1057CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1058
1059# Default kernel image to build when no specific target is given.
1060# KBUILD_IMAGE may be overruled on the command line or
1061# set in the environment
1062# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1063# this default value
1064export KBUILD_IMAGE ?= vmlinux
1065
1066#
1067# INSTALL_PATH specifies where to place the updated kernel and system map
1068# images. Default is /boot, but you can set it to other values
1069export	INSTALL_PATH ?= /boot
1070
1071#
1072# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1073# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1074# an argument if needed. Otherwise it defaults to the kernel install path
1075#
1076export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1077
1078#
1079# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1080# relocations required by build roots.  This is not defined in the
1081# makefile but the argument can be passed to make if needed.
1082#
1083
1084MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1085export MODLIB
1086
1087PHONY += prepare0
1088
1089export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1090export MODORDER := $(extmod_prefix)modules.order
1091export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1092
1093ifeq ($(KBUILD_EXTMOD),)
1094
1095build-dir	:= .
1096clean-dirs	:= $(sort . Documentation \
1097		     $(patsubst %/,%,$(filter %/, $(core-) \
1098			$(drivers-) $(libs-))))
1099
1100export ARCH_CORE	:= $(core-y)
1101export ARCH_LIB		:= $(filter %/, $(libs-y))
1102export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1103# Externally visible symbols (used by link-vmlinux.sh)
1104
1105KBUILD_VMLINUX_OBJS := ./built-in.a
1106ifdef CONFIG_MODULES
1107KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1108KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1109else
1110KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1111endif
1112
1113export KBUILD_VMLINUX_LIBS
1114export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1115
1116ifdef CONFIG_TRIM_UNUSED_KSYMS
1117# For the kernel to actually contain only the needed exported symbols,
1118# we have to build modules as well to determine what those symbols are.
1119KBUILD_MODULES := 1
1120endif
1121
1122# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1123quiet_cmd_ar_vmlinux.a = AR      $@
1124      cmd_ar_vmlinux.a = \
1125	rm -f $@; \
1126	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1127	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1128
1129targets += vmlinux.a
1130vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1131	$(call if_changed,ar_vmlinux.a)
1132
1133PHONY += vmlinux_o
1134vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1135	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1136
1137vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1138	@:
1139
1140PHONY += vmlinux
1141# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1142# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1143# unrelated; the decompressors just happen to have the same base name,
1144# arch/*/boot/compressed/vmlinux.
1145# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1146#
1147# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1148#   https://savannah.gnu.org/bugs/?61463
1149# For Make > 4.4, the following simple code will work:
1150#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1151vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1152vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1153vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1154	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1155
1156# The actual objects are generated when descending,
1157# make sure no implicit rule kicks in
1158$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1159
1160ifeq ($(origin KERNELRELEASE),file)
1161filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1162else
1163filechk_kernel.release = echo $(KERNELRELEASE)
1164endif
1165
1166# Store (new) KERNELRELEASE string in include/config/kernel.release
1167include/config/kernel.release: FORCE
1168	$(call filechk,kernel.release)
1169
1170# Additional helpers built in scripts/
1171# Carefully list dependencies so we do not try to build scripts twice
1172# in parallel
1173PHONY += scripts
1174scripts: scripts_basic scripts_dtc
1175	$(Q)$(MAKE) $(build)=$(@)
1176
1177# Things we need to do before we recursively start building the kernel
1178# or the modules are listed in "prepare".
1179# A multi level approach is used. prepareN is processed before prepareN-1.
1180# archprepare is used in arch Makefiles and when processed asm symlink,
1181# version.h and scripts_basic is processed / created.
1182
1183PHONY += prepare archprepare
1184
1185archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1186	asm-generic $(version_h) include/generated/utsrelease.h \
1187	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1188
1189prepare0: archprepare
1190	$(Q)$(MAKE) $(build)=scripts/mod
1191	$(Q)$(MAKE) $(build)=. prepare
1192
1193# All the preparing..
1194prepare: prepare0
1195ifdef CONFIG_RUST
1196	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1197	$(Q)$(MAKE) $(build)=rust
1198endif
1199
1200PHONY += remove-stale-files
1201remove-stale-files:
1202	$(Q)$(srctree)/scripts/remove-stale-files
1203
1204# Support for using generic headers in asm-generic
1205asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1206
1207PHONY += asm-generic uapi-asm-generic
1208asm-generic: uapi-asm-generic
1209	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1210	generic=include/asm-generic
1211uapi-asm-generic:
1212	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1213	generic=include/uapi/asm-generic
1214
1215# Generate some files
1216# ---------------------------------------------------------------------------
1217
1218# KERNELRELEASE can change from a few different places, meaning version.h
1219# needs to be updated, so this check is forced on all builds
1220
1221uts_len := 64
1222define filechk_utsrelease.h
1223	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1224	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1225	  exit 1;                                                         \
1226	fi;                                                               \
1227	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1228endef
1229
1230define filechk_version.h
1231	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1232		echo \#define LINUX_VERSION_CODE $(shell                 \
1233		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1234	else                                                             \
1235		echo \#define LINUX_VERSION_CODE $(shell                 \
1236		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1237	fi;                                                              \
1238	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1239	((c) > 255 ? 255 : (c)))';                                       \
1240	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1241	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1242	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1243endef
1244
1245$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1246$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1247$(version_h): FORCE
1248	$(call filechk,version.h)
1249
1250include/generated/utsrelease.h: include/config/kernel.release FORCE
1251	$(call filechk,utsrelease.h)
1252
1253filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1254	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1255
1256include/generated/compile.h: FORCE
1257	$(call filechk,compile.h)
1258
1259PHONY += headerdep
1260headerdep:
1261	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1262	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1263
1264# ---------------------------------------------------------------------------
1265# Kernel headers
1266
1267#Default location for installed headers
1268export INSTALL_HDR_PATH = $(objtree)/usr
1269
1270quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1271      cmd_headers_install = \
1272	mkdir -p $(INSTALL_HDR_PATH); \
1273	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1274	usr/include $(INSTALL_HDR_PATH)
1275
1276PHONY += headers_install
1277headers_install: headers
1278	$(call cmd,headers_install)
1279
1280PHONY += archheaders archscripts
1281
1282hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1283
1284PHONY += headers
1285headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1286	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1287	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1288	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1289
1290ifdef CONFIG_HEADERS_INSTALL
1291prepare: headers
1292endif
1293
1294PHONY += scripts_unifdef
1295scripts_unifdef: scripts_basic
1296	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1297
1298# ---------------------------------------------------------------------------
1299# Install
1300
1301# Many distributions have the custom install script, /sbin/installkernel.
1302# If DKMS is installed, 'make install' will eventually recurse back
1303# to this Makefile to build and install external modules.
1304# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1305
1306quiet_cmd_install = INSTALL $(INSTALL_PATH)
1307      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1308
1309# ---------------------------------------------------------------------------
1310# vDSO install
1311
1312PHONY += vdso_install
1313vdso_install: export INSTALL_FILES = $(vdso-install-y)
1314vdso_install:
1315	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1316
1317# ---------------------------------------------------------------------------
1318# Tools
1319
1320ifdef CONFIG_OBJTOOL
1321prepare: tools/objtool
1322endif
1323
1324ifdef CONFIG_BPF
1325ifdef CONFIG_DEBUG_INFO_BTF
1326prepare: tools/bpf/resolve_btfids
1327endif
1328endif
1329
1330PHONY += resolve_btfids_clean
1331
1332resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1333
1334# tools/bpf/resolve_btfids directory might not exist
1335# in output directory, skip its clean in that case
1336resolve_btfids_clean:
1337ifneq ($(wildcard $(resolve_btfids_O)),)
1338	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1339endif
1340
1341# Clear a bunch of variables before executing the submake
1342ifeq ($(quiet),silent_)
1343tools_silent=s
1344endif
1345
1346tools/: FORCE
1347	$(Q)mkdir -p $(objtree)/tools
1348	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1349
1350tools/%: FORCE
1351	$(Q)mkdir -p $(objtree)/tools
1352	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1353
1354# ---------------------------------------------------------------------------
1355# Kernel selftest
1356
1357PHONY += kselftest
1358kselftest: headers
1359	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1360
1361kselftest-%: headers FORCE
1362	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1363
1364PHONY += kselftest-merge
1365kselftest-merge:
1366	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1367	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1368		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1369	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1370
1371# ---------------------------------------------------------------------------
1372# Devicetree files
1373
1374ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1375dtstree := arch/$(SRCARCH)/boot/dts
1376endif
1377
1378ifneq ($(dtstree),)
1379
1380%.dtb: dtbs_prepare
1381	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1382
1383%.dtbo: dtbs_prepare
1384	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1385
1386PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1387dtbs: dtbs_prepare
1388	$(Q)$(MAKE) $(build)=$(dtstree)
1389
1390# include/config/kernel.release is actually needed when installing DTBs because
1391# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1392# dtbs_install depend on it as dtbs_install may run as root.
1393dtbs_prepare: include/config/kernel.release scripts_dtc
1394
1395ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1396export CHECK_DTBS=y
1397endif
1398
1399ifneq ($(CHECK_DTBS),)
1400dtbs_prepare: dt_binding_check
1401endif
1402
1403dtbs_check: dtbs
1404
1405dtbs_install:
1406	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1407
1408ifdef CONFIG_OF_EARLY_FLATTREE
1409all: dtbs
1410endif
1411
1412endif
1413
1414PHONY += scripts_dtc
1415scripts_dtc: scripts_basic
1416	$(Q)$(MAKE) $(build)=scripts/dtc
1417
1418ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1419export CHECK_DT_BINDING=y
1420endif
1421
1422PHONY += dt_binding_check
1423dt_binding_check: scripts_dtc
1424	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1425
1426PHONY += dt_compatible_check
1427dt_compatible_check: dt_binding_check
1428	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1429
1430# ---------------------------------------------------------------------------
1431# Modules
1432
1433ifdef CONFIG_MODULES
1434
1435# By default, build modules as well
1436
1437all: modules
1438
1439# When we're building modules with modversions, we need to consider
1440# the built-in objects during the descend as well, in order to
1441# make sure the checksums are up to date before we record them.
1442ifdef CONFIG_MODVERSIONS
1443  KBUILD_BUILTIN := 1
1444endif
1445
1446# Build modules
1447#
1448
1449# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1450# is an exception.
1451ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1452KBUILD_BUILTIN := 1
1453modules: vmlinux
1454endif
1455
1456modules: modules_prepare
1457
1458# Target to prepare building external modules
1459modules_prepare: prepare
1460	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1461
1462endif # CONFIG_MODULES
1463
1464###
1465# Cleaning is done on three levels.
1466# make clean     Delete most generated files
1467#                Leave enough to build external modules
1468# make mrproper  Delete the current configuration, and all generated files
1469# make distclean Remove editor backup files, patch leftover files and the like
1470
1471# Directories & files removed with 'make clean'
1472CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1473	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1474	       compile_commands.json .thinlto-cache rust/test \
1475	       rust-project.json .vmlinux.objs .vmlinux.export.c
1476
1477# Directories & files removed with 'make mrproper'
1478MRPROPER_FILES += include/config include/generated          \
1479		  arch/$(SRCARCH)/include/generated .objdiff \
1480		  debian snap tar-install \
1481		  .config .config.old .version \
1482		  Module.symvers \
1483		  certs/signing_key.pem \
1484		  certs/x509.genkey \
1485		  vmlinux-gdb.py \
1486		  rpmbuild \
1487		  rust/libmacros.so
1488
1489# clean - Delete most, but leave enough to build external modules
1490#
1491clean: rm-files := $(CLEAN_FILES)
1492
1493PHONY += archclean vmlinuxclean
1494
1495vmlinuxclean:
1496	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1497	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1498
1499clean: archclean vmlinuxclean resolve_btfids_clean
1500
1501# mrproper - Delete all generated files, including .config
1502#
1503mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1504mrproper-dirs      := $(addprefix _mrproper_,scripts)
1505
1506PHONY += $(mrproper-dirs) mrproper
1507$(mrproper-dirs):
1508	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1509
1510mrproper: clean $(mrproper-dirs)
1511	$(call cmd,rmfiles)
1512	@find . $(RCS_FIND_IGNORE) \
1513		\( -name '*.rmeta' \) \
1514		-type f -print | xargs rm -f
1515
1516# distclean
1517#
1518PHONY += distclean
1519
1520distclean: mrproper
1521	@find . $(RCS_FIND_IGNORE) \
1522		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1523		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1524		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1525		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1526		-type f -print | xargs rm -f
1527
1528
1529# Packaging of the kernel to various formats
1530# ---------------------------------------------------------------------------
1531
1532%src-pkg: FORCE
1533	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1534%pkg: include/config/kernel.release FORCE
1535	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1536
1537# Brief documentation of the typical targets used
1538# ---------------------------------------------------------------------------
1539
1540boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1541boards := $(sort $(notdir $(boards)))
1542board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1543board-dirs := $(sort $(notdir $(board-dirs:/=)))
1544
1545PHONY += help
1546help:
1547	@echo  'Cleaning targets:'
1548	@echo  '  clean		  - Remove most generated files but keep the config and'
1549	@echo  '                    enough build support to build external modules'
1550	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1551	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1552	@echo  ''
1553	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1554	@echo  ''
1555	@echo  'Other generic targets:'
1556	@echo  '  all		  - Build all targets marked with [*]'
1557	@echo  '* vmlinux	  - Build the bare kernel'
1558	@echo  '* modules	  - Build all modules'
1559	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1560	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1561	@echo  '  dir/            - Build all files in dir and below'
1562	@echo  '  dir/file.[ois]  - Build specified target only'
1563	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1564	@echo  '                    (requires compiler support for LLVM assembly generation)'
1565	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1566	@echo  '                    (requires a recent binutils and recent build (System.map))'
1567	@echo  '  dir/file.ko     - Build module including final link'
1568	@echo  '  modules_prepare - Set up for building external modules'
1569	@echo  '  tags/TAGS	  - Generate tags file for editors'
1570	@echo  '  cscope	  - Generate cscope index'
1571	@echo  '  gtags           - Generate GNU GLOBAL index'
1572	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1573	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1574	@echo  '  image_name	  - Output the image name (use with make -s)'
1575	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1576	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1577	 echo  ''
1578	@echo  'Static analysers:'
1579	@echo  '  checkstack      - Generate a list of stack hogs'
1580	@echo  '  versioncheck    - Sanity check on version.h usage'
1581	@echo  '  includecheck    - Check for duplicate included header files'
1582	@echo  '  export_report   - List the usages of all exported symbols'
1583	@echo  '  headerdep       - Detect inclusion cycles in headers'
1584	@echo  '  coccicheck      - Check with Coccinelle'
1585	@echo  '  clang-analyzer  - Check with clang static analyzer'
1586	@echo  '  clang-tidy      - Check with clang-tidy'
1587	@echo  ''
1588	@echo  'Tools:'
1589	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1590	@echo  ''
1591	@echo  'Kernel selftest:'
1592	@echo  '  kselftest         - Build and run kernel selftest'
1593	@echo  '                      Build, install, and boot kernel before'
1594	@echo  '                      running kselftest on it'
1595	@echo  '                      Run as root for full coverage'
1596	@echo  '  kselftest-all     - Build kernel selftest'
1597	@echo  '  kselftest-install - Build and install kernel selftest'
1598	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1599	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1600	@echo  '		      kselftest to existing .config.'
1601	@echo  ''
1602	@echo  'Rust targets:'
1603	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1604	@echo  '		    available and, if not, explains why.'
1605	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1606	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1607	@echo  '		    is formatted, printing a diff otherwise.'
1608	@echo  '  rustdoc	  - Generate Rust documentation'
1609	@echo  '		    (requires kernel .config)'
1610	@echo  '  rusttest        - Runs the Rust tests'
1611	@echo  '                    (requires kernel .config; downloads external repos)'
1612	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1613	@echo  '		    (requires kernel .config)'
1614	@echo  '  dir/file.[os]   - Build specified target only'
1615	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1616	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1617	@echo  '                    The output is not intended to be compilable.'
1618	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1619	@echo  ''
1620	@$(if $(dtstree), \
1621		echo 'Devicetree:'; \
1622		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1623		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1624		echo '  dt_binding_check - Validate device tree binding documents'; \
1625		echo '  dtbs_check       - Validate device tree source files';\
1626		echo '')
1627
1628	@echo 'Userspace tools targets:'
1629	@echo '  use "make tools/help"'
1630	@echo '  or  "cd tools; make help"'
1631	@echo  ''
1632	@echo  'Kernel packaging:'
1633	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1634	@echo  ''
1635	@echo  'Documentation targets:'
1636	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1637	@echo  ''
1638	@echo  'Architecture-specific targets ($(SRCARCH)):'
1639	@$(or $(archhelp),\
1640		echo '  No architecture-specific help defined for $(SRCARCH)')
1641	@echo  ''
1642	@$(if $(boards), \
1643		$(foreach b, $(boards), \
1644		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1645		echo '')
1646	@$(if $(board-dirs), \
1647		$(foreach b, $(board-dirs), \
1648		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1649		printf "  %-16s - Show all of the above\\n" help-boards; \
1650		echo '')
1651
1652	@echo  '  make V=n   [targets] 1: verbose build'
1653	@echo  '                       2: give reason for rebuild of target'
1654	@echo  '                       V=1 and V=2 can be combined with V=12'
1655	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1656	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1657	@echo  '                       (sparse by default)'
1658	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1659	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1660	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1661	@echo  '		1: warnings which may be relevant and do not occur too often'
1662	@echo  '		2: warnings which occur quite often but may still be relevant'
1663	@echo  '		3: more obscure warnings, can most likely be ignored'
1664	@echo  '		e: warnings are being treated as errors'
1665	@echo  '		Multiple levels can be combined with W=12 or W=123'
1666	@$(if $(dtstree), \
1667		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1668		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1669		)
1670	@echo  ''
1671	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1672	@echo  'For further info see the ./README file'
1673
1674
1675help-board-dirs := $(addprefix help-,$(board-dirs))
1676
1677help-boards: $(help-board-dirs)
1678
1679boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1680
1681$(help-board-dirs): help-%:
1682	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1683	@$(if $(boards-per-dir), \
1684		$(foreach b, $(boards-per-dir), \
1685		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1686		echo '')
1687
1688
1689# Documentation targets
1690# ---------------------------------------------------------------------------
1691DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1692	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1693PHONY += $(DOC_TARGETS)
1694$(DOC_TARGETS):
1695	$(Q)$(MAKE) $(build)=Documentation $@
1696
1697
1698# Rust targets
1699# ---------------------------------------------------------------------------
1700
1701# "Is Rust available?" target
1702PHONY += rustavailable
1703rustavailable:
1704	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1705
1706# Documentation target
1707#
1708# Using the singular to avoid running afoul of `no-dot-config-targets`.
1709PHONY += rustdoc
1710rustdoc: prepare
1711	$(Q)$(MAKE) $(build)=rust $@
1712
1713# Testing target
1714PHONY += rusttest
1715rusttest: prepare
1716	$(Q)$(MAKE) $(build)=rust $@
1717
1718# Formatting targets
1719PHONY += rustfmt rustfmtcheck
1720
1721# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1722#
1723# We match using absolute paths since `find` does not resolve them
1724# when matching, which is a problem when e.g. `srctree` is `..`.
1725# We `grep` afterwards in order to remove the directory entry itself.
1726rustfmt:
1727	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1728		-o -path $(abs_srctree)/rust/alloc -prune \
1729		-o -path $(abs_objtree)/rust/test -prune \
1730		| grep -Fv $(abs_srctree)/rust/alloc \
1731		| grep -Fv $(abs_objtree)/rust/test \
1732		| grep -Fv generated \
1733		| xargs $(RUSTFMT) $(rustfmt_flags)
1734
1735rustfmtcheck: rustfmt_flags = --check
1736rustfmtcheck: rustfmt
1737
1738# Misc
1739# ---------------------------------------------------------------------------
1740
1741PHONY += misc-check
1742misc-check:
1743	$(Q)$(srctree)/scripts/misc-check
1744
1745all: misc-check
1746
1747PHONY += scripts_gdb
1748scripts_gdb: prepare0
1749	$(Q)$(MAKE) $(build)=scripts/gdb
1750	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1751
1752ifdef CONFIG_GDB_SCRIPTS
1753all: scripts_gdb
1754endif
1755
1756else # KBUILD_EXTMOD
1757
1758filechk_kernel.release = echo $(KERNELRELEASE)
1759
1760###
1761# External module support.
1762# When building external modules the kernel used as basis is considered
1763# read-only, and no consistency checks are made and the make
1764# system is not used on the basis kernel. If updates are required
1765# in the basis kernel ordinary make commands (without M=...) must be used.
1766
1767# We are always building only modules.
1768KBUILD_BUILTIN :=
1769KBUILD_MODULES := 1
1770
1771build-dir := $(KBUILD_EXTMOD)
1772
1773compile_commands.json: $(extmod_prefix)compile_commands.json
1774PHONY += compile_commands.json
1775
1776clean-dirs := $(KBUILD_EXTMOD)
1777clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1778	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1779
1780PHONY += prepare
1781# now expand this into a simple variable to reduce the cost of shell evaluations
1782prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1783prepare:
1784	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1785		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1786		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1787		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1788	fi
1789
1790PHONY += help
1791help:
1792	@echo  '  Building external modules.'
1793	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1794	@echo  ''
1795	@echo  '  modules         - default target, build the module(s)'
1796	@echo  '  modules_install - install the module'
1797	@echo  '  clean           - remove generated files in module directory only'
1798	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1799	@echo  ''
1800
1801ifndef CONFIG_MODULES
1802modules modules_install: __external_modules_error
1803__external_modules_error:
1804	@echo >&2 '***'
1805	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1806	@echo >&2 '*** You cannot build or install external modules.'
1807	@echo >&2 '***'
1808	@false
1809endif
1810
1811endif # KBUILD_EXTMOD
1812
1813# ---------------------------------------------------------------------------
1814# Modules
1815
1816PHONY += modules modules_install modules_sign modules_prepare
1817
1818modules_install:
1819	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1820	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1821
1822ifeq ($(CONFIG_MODULE_SIG),y)
1823# modules_sign is a subset of modules_install.
1824# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1825modules_sign: modules_install
1826	@:
1827else
1828modules_sign:
1829	@echo >&2 '***'
1830	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1831	@echo >&2 '***'
1832	@false
1833endif
1834
1835ifdef CONFIG_MODULES
1836
1837$(MODORDER): $(build-dir)
1838	@:
1839
1840# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1841# This is solely useful to speed up test compiles.
1842modules: modpost
1843ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1844	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1845endif
1846
1847PHONY += modules_check
1848modules_check: $(MODORDER)
1849	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1850
1851else # CONFIG_MODULES
1852
1853modules:
1854	@:
1855
1856KBUILD_MODULES :=
1857
1858endif # CONFIG_MODULES
1859
1860PHONY += modpost
1861modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1862	 $(if $(KBUILD_MODULES), modules_check)
1863	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1864
1865# Single targets
1866# ---------------------------------------------------------------------------
1867# To build individual files in subdirectories, you can do like this:
1868#
1869#   make foo/bar/baz.s
1870#
1871# The supported suffixes for single-target are listed in 'single-targets'
1872#
1873# To build only under specific subdirectories, you can do like this:
1874#
1875#   make foo/bar/baz/
1876
1877ifdef single-build
1878
1879# .ko is special because modpost is needed
1880single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1881single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1882		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1883
1884$(single-ko): single_modules
1885	@:
1886$(single-no-ko): $(build-dir)
1887	@:
1888
1889# Remove MODORDER when done because it is not the real one.
1890PHONY += single_modules
1891single_modules: $(single-no-ko) modules_prepare
1892	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$(m:%.ko=%.o);) } > $(MODORDER)
1893	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1894ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1895	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1896endif
1897	$(Q)rm -f $(MODORDER)
1898
1899single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1900
1901KBUILD_MODULES := 1
1902
1903endif
1904
1905# Preset locale variables to speed up the build process. Limit locale
1906# tweaks to this spot to avoid wrong language settings when running
1907# make menuconfig etc.
1908# Error messages still appears in the original language
1909PHONY += $(build-dir)
1910$(build-dir): prepare
1911	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1912
1913clean-dirs := $(addprefix _clean_, $(clean-dirs))
1914PHONY += $(clean-dirs) clean
1915$(clean-dirs):
1916	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1917
1918clean: $(clean-dirs)
1919	$(call cmd,rmfiles)
1920	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1921		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
1922		-o -name '*.ko.*' \
1923		-o -name '*.dtb' -o -name '*.dtbo' \
1924		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
1925		-o -name '*.dt.yaml' \
1926		-o -name '*.dwo' -o -name '*.lst' \
1927		-o -name '*.su' -o -name '*.mod' \
1928		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1929		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1930		-o -name '*.asn1.[ch]' \
1931		-o -name '*.symtypes' -o -name 'modules.order' \
1932		-o -name '*.c.[012]*.*' \
1933		-o -name '*.ll' \
1934		-o -name '*.gcno' \
1935		-o -name '*.*.symversions' \) -type f -print \
1936		-o -name '.tmp_*' -print \
1937		| xargs rm -rf
1938
1939# Generate tags for editors
1940# ---------------------------------------------------------------------------
1941quiet_cmd_tags = GEN     $@
1942      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1943
1944tags TAGS cscope gtags: FORCE
1945	$(call cmd,tags)
1946
1947# IDE support targets
1948PHONY += rust-analyzer
1949rust-analyzer:
1950	$(Q)$(MAKE) $(build)=rust $@
1951
1952# Script to generate missing namespace dependencies
1953# ---------------------------------------------------------------------------
1954
1955PHONY += nsdeps
1956nsdeps: export KBUILD_NSDEPS=1
1957nsdeps: modules
1958	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1959
1960# Clang Tooling
1961# ---------------------------------------------------------------------------
1962
1963quiet_cmd_gen_compile_commands = GEN     $@
1964      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1965
1966$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1967	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
1968	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1969	$(call if_changed,gen_compile_commands)
1970
1971targets += $(extmod_prefix)compile_commands.json
1972
1973PHONY += clang-tidy clang-analyzer
1974
1975ifdef CONFIG_CC_IS_CLANG
1976quiet_cmd_clang_tools = CHECK   $<
1977      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1978
1979clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1980	$(call cmd,clang_tools)
1981else
1982clang-tidy clang-analyzer:
1983	@echo "$@ requires CC=clang" >&2
1984	@false
1985endif
1986
1987# Scripts to check various things for consistency
1988# ---------------------------------------------------------------------------
1989
1990PHONY += includecheck versioncheck coccicheck export_report
1991
1992includecheck:
1993	find $(srctree)/* $(RCS_FIND_IGNORE) \
1994		-name '*.[hcS]' -type f -print | sort \
1995		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1996
1997versioncheck:
1998	find $(srctree)/* $(RCS_FIND_IGNORE) \
1999		-name '*.[hcS]' -type f -print | sort \
2000		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2001
2002coccicheck:
2003	$(Q)$(BASH) $(srctree)/scripts/$@
2004
2005export_report:
2006	$(PERL) $(srctree)/scripts/export_report.pl
2007
2008PHONY += checkstack kernelrelease kernelversion image_name
2009
2010# UML needs a little special treatment here.  It wants to use the host
2011# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2012# else wants $(ARCH), including people doing cross-builds, which means
2013# that $(SUBARCH) doesn't work here.
2014ifeq ($(ARCH), um)
2015CHECKSTACK_ARCH := $(SUBARCH)
2016else
2017CHECKSTACK_ARCH := $(ARCH)
2018endif
2019checkstack:
2020	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2021	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2022
2023kernelrelease:
2024	@$(filechk_kernel.release)
2025
2026kernelversion:
2027	@echo $(KERNELVERSION)
2028
2029image_name:
2030	@echo $(KBUILD_IMAGE)
2031
2032PHONY += run-command
2033run-command:
2034	$(Q)$(KBUILD_RUN_COMMAND)
2035
2036quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2037      cmd_rmfiles = rm -rf $(rm-files)
2038
2039# read saved command lines for existing targets
2040existing-targets := $(wildcard $(sort $(targets)))
2041
2042-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2043
2044endif # config-build
2045endif # mixed-build
2046endif # need-sub-make
2047
2048PHONY += FORCE
2049FORCE:
2050
2051# Declare the contents of the PHONY variable as phony.  We keep that
2052# information in a variable so we can use it in if_changed and friends.
2053.PHONY: $(PHONY)
2054