xref: /linux/Makefile (revision a9c9a6f741cdaa2fa9ba24a790db8d07295761e3)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 14
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Opossums on Parade
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
14$(if $(filter __%, $(MAKECMDGOALS)), \
15	$(error targets prefixed with '__' are only for internal use))
16
17# That's our default target when none is given on the command line
18PHONY := __all
19__all:
20
21# We are using a recursive build, so we need to do a little thinking
22# to get the ordering right.
23#
24# Most importantly: sub-Makefiles should only ever modify files in
25# their own directory. If in some directory we have a dependency on
26# a file in another dir (which doesn't happen often, but it's often
27# unavoidable when linking the built-in.a targets which finally
28# turn into vmlinux), we will call a sub make in that other dir, and
29# after that we are sure that everything which is in that other dir
30# is now up to date.
31#
32# The only cases where we need to modify files which have global
33# effects are thus separated out and done before the recursive
34# descending is started. They are now explicitly listed as the
35# prepare rule.
36
37ifneq ($(sub_make_done),1)
38
39# Do not use make's built-in rules and variables
40# (this increases performance and avoids hard-to-debug behaviour)
41MAKEFLAGS += -rR
42
43# Avoid funny character set dependencies
44unexport LC_ALL
45LC_COLLATE=C
46LC_NUMERIC=C
47export LC_COLLATE LC_NUMERIC
48
49# Avoid interference with shell env settings
50unexport GREP_OPTIONS
51
52# Beautify output
53# ---------------------------------------------------------------------------
54#
55# Normally, we echo the whole command before executing it. By making
56# that echo $($(quiet)$(cmd)), we now have the possibility to set
57# $(quiet) to choose other forms of output instead, e.g.
58#
59#         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
60#         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
61#
62# If $(quiet) is empty, the whole command will be printed.
63# If it is set to "quiet_", only the short version will be printed.
64# If it is set to "silent_", nothing will be printed at all, since
65# the variable $(silent_cmd_cc_o_c) doesn't exist.
66#
67# A simple variant is to prefix commands with $(Q) - that's useful
68# for commands that shall be hidden in non-verbose mode.
69#
70#	$(Q)ln $@ :<
71#
72# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
73# If KBUILD_VERBOSE equals 1 then the above command is displayed.
74# If KBUILD_VERBOSE equals 2 then give the reason why each target is rebuilt.
75#
76# To put more focus on warnings, be less verbose as default
77# Use 'make V=1' to see the full commands
78
79ifeq ("$(origin V)", "command line")
80  KBUILD_VERBOSE = $(V)
81endif
82ifndef KBUILD_VERBOSE
83  KBUILD_VERBOSE = 0
84endif
85
86ifeq ($(KBUILD_VERBOSE),1)
87  quiet =
88  Q =
89else
90  quiet=quiet_
91  Q = @
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96
97ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
98  quiet=silent_
99  KBUILD_VERBOSE = 0
100endif
101
102export quiet Q KBUILD_VERBOSE
103
104# Call a source code checker (by default, "sparse") as part of the
105# C compilation.
106#
107# Use 'make C=1' to enable checking of only re-compiled files.
108# Use 'make C=2' to enable checking of *all* source files, regardless
109# of whether they are re-compiled or not.
110#
111# See the file "Documentation/dev-tools/sparse.rst" for more details,
112# including where to get the "sparse" utility.
113
114ifeq ("$(origin C)", "command line")
115  KBUILD_CHECKSRC = $(C)
116endif
117ifndef KBUILD_CHECKSRC
118  KBUILD_CHECKSRC = 0
119endif
120
121export KBUILD_CHECKSRC
122
123# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
124# directory of external module to build. Setting M= takes precedence.
125ifeq ("$(origin M)", "command line")
126  KBUILD_EXTMOD := $(M)
127endif
128
129$(if $(word 2, $(KBUILD_EXTMOD)), \
130	$(error building multiple external modules is not supported))
131
132# Remove trailing slashes
133ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
134KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
135endif
136
137export KBUILD_EXTMOD
138
139# Kbuild will save output files in the current working directory.
140# This does not need to match to the root of the kernel source tree.
141#
142# For example, you can do this:
143#
144#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
145#
146# If you want to save output files in a different location, there are
147# two syntaxes to specify it.
148#
149# 1) O=
150# Use "make O=dir/to/store/output/files/"
151#
152# 2) Set KBUILD_OUTPUT
153# Set the environment variable KBUILD_OUTPUT to point to the output directory.
154# export KBUILD_OUTPUT=dir/to/store/output/files/; make
155#
156# The O= assignment takes precedence over the KBUILD_OUTPUT environment
157# variable.
158
159# Do we want to change the working directory?
160ifeq ("$(origin O)", "command line")
161  KBUILD_OUTPUT := $(O)
162endif
163
164ifneq ($(KBUILD_OUTPUT),)
165# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
166# expand a shell special character '~'. We use a somewhat tedious way here.
167abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
168$(if $(abs_objtree),, \
169     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
170
171# $(realpath ...) resolves symlinks
172abs_objtree := $(realpath $(abs_objtree))
173else
174abs_objtree := $(CURDIR)
175endif # ifneq ($(KBUILD_OUTPUT),)
176
177ifeq ($(abs_objtree),$(CURDIR))
178# Suppress "Entering directory ..." unless we are changing the work directory.
179MAKEFLAGS += --no-print-directory
180else
181need-sub-make := 1
182endif
183
184this-makefile := $(lastword $(MAKEFILE_LIST))
185abs_srctree := $(realpath $(dir $(this-makefile)))
186
187ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
188$(error source directory cannot contain spaces or colons)
189endif
190
191ifneq ($(abs_srctree),$(abs_objtree))
192# Look for make include files relative to root of kernel src
193#
194# This does not become effective immediately because MAKEFLAGS is re-parsed
195# once after the Makefile is read. We need to invoke sub-make.
196MAKEFLAGS += --include-dir=$(abs_srctree)
197need-sub-make := 1
198endif
199
200ifneq ($(filter 3.%,$(MAKE_VERSION)),)
201# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
202# We need to invoke sub-make to avoid implicit rules in the top Makefile.
203need-sub-make := 1
204# Cancel implicit rules for this Makefile.
205$(this-makefile): ;
206endif
207
208export abs_srctree abs_objtree
209export sub_make_done := 1
210
211ifeq ($(need-sub-make),1)
212
213PHONY += $(MAKECMDGOALS) __sub-make
214
215$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
216	@:
217
218# Invoke a second make in the output directory, passing relevant variables
219__sub-make:
220	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
221
222endif # need-sub-make
223endif # sub_make_done
224
225# We process the rest of the Makefile if this is the final invocation of make
226ifeq ($(need-sub-make),)
227
228# Do not print "Entering directory ...",
229# but we want to display it when entering to the output directory
230# so that IDEs/editors are able to understand relative filenames.
231MAKEFLAGS += --no-print-directory
232
233ifeq ($(abs_srctree),$(abs_objtree))
234        # building in the source tree
235        srctree := .
236	building_out_of_srctree :=
237else
238        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
239                # building in a subdirectory of the source tree
240                srctree := ..
241        else
242                srctree := $(abs_srctree)
243        endif
244	building_out_of_srctree := 1
245endif
246
247ifneq ($(KBUILD_ABS_SRCTREE),)
248srctree := $(abs_srctree)
249endif
250
251objtree		:= .
252VPATH		:= $(srctree)
253
254export building_out_of_srctree srctree objtree VPATH
255
256# To make sure we do not include .config for any of the *config targets
257# catch them early, and hand them over to scripts/kconfig/Makefile
258# It is allowed to specify more targets when calling make, including
259# mixing *config targets and build targets.
260# For example 'make oldconfig all'.
261# Detect when mixed targets is specified, and make a second invocation
262# of make so .config is not included in this case either (for *config).
263
264version_h := include/generated/uapi/linux/version.h
265
266clean-targets := %clean mrproper cleandocs
267no-dot-config-targets := $(clean-targets) \
268			 cscope gtags TAGS tags help% %docs check% coccicheck \
269			 $(version_h) headers headers_% archheaders archscripts \
270			 %asm-generic kernelversion %src-pkg dt_binding_check \
271			 outputmakefile
272# Installation targets should not require compiler. Unfortunately, vdso_install
273# is an exception where build artifacts may be updated. This must be fixed.
274no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
275			headers_install modules_install kernelrelease image_name
276no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
277			  image_name
278single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
279
280config-build	:=
281mixed-build	:=
282need-config	:= 1
283need-compiler	:= 1
284may-sync-config	:= 1
285single-build	:=
286
287ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
288	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
289		need-config :=
290	endif
291endif
292
293ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
294	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
295		need-compiler :=
296	endif
297endif
298
299ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
300	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
301		may-sync-config :=
302	endif
303endif
304
305ifneq ($(KBUILD_EXTMOD),)
306	may-sync-config :=
307endif
308
309ifeq ($(KBUILD_EXTMOD),)
310        ifneq ($(filter %config,$(MAKECMDGOALS)),)
311		config-build := 1
312                ifneq ($(words $(MAKECMDGOALS)),1)
313			mixed-build := 1
314                endif
315        endif
316endif
317
318# We cannot build single targets and the others at the same time
319ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
320	single-build := 1
321	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
322		mixed-build := 1
323	endif
324endif
325
326# For "make -j clean all", "make -j mrproper defconfig all", etc.
327ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
328        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
329		mixed-build := 1
330        endif
331endif
332
333# install and modules_install need also be processed one by one
334ifneq ($(filter install,$(MAKECMDGOALS)),)
335        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
336		mixed-build := 1
337        endif
338endif
339
340ifdef mixed-build
341# ===========================================================================
342# We're called with mixed targets (*config and build targets).
343# Handle them one by one.
344
345PHONY += $(MAKECMDGOALS) __build_one_by_one
346
347$(MAKECMDGOALS): __build_one_by_one
348	@:
349
350__build_one_by_one:
351	$(Q)set -e; \
352	for i in $(MAKECMDGOALS); do \
353		$(MAKE) -f $(srctree)/Makefile $$i; \
354	done
355
356else # !mixed-build
357
358include $(srctree)/scripts/Kbuild.include
359
360# Read KERNELRELEASE from include/config/kernel.release (if it exists)
361KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
362KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
363export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
364
365include $(srctree)/scripts/subarch.include
366
367# Cross compiling and selecting different set of gcc/bin-utils
368# ---------------------------------------------------------------------------
369#
370# When performing cross compilation for other architectures ARCH shall be set
371# to the target architecture. (See arch/* for the possibilities).
372# ARCH can be set during invocation of make:
373# make ARCH=ia64
374# Another way is to have ARCH set in the environment.
375# The default ARCH is the host where make is executed.
376
377# CROSS_COMPILE specify the prefix used for all executables used
378# during compilation. Only gcc and related bin-utils executables
379# are prefixed with $(CROSS_COMPILE).
380# CROSS_COMPILE can be set on the command line
381# make CROSS_COMPILE=ia64-linux-
382# Alternatively CROSS_COMPILE can be set in the environment.
383# Default value for CROSS_COMPILE is not to prefix executables
384# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
385ARCH		?= $(SUBARCH)
386
387# Architecture as present in compile.h
388UTS_MACHINE 	:= $(ARCH)
389SRCARCH 	:= $(ARCH)
390
391# Additional ARCH settings for x86
392ifeq ($(ARCH),i386)
393        SRCARCH := x86
394endif
395ifeq ($(ARCH),x86_64)
396        SRCARCH := x86
397endif
398
399# Additional ARCH settings for sparc
400ifeq ($(ARCH),sparc32)
401       SRCARCH := sparc
402endif
403ifeq ($(ARCH),sparc64)
404       SRCARCH := sparc
405endif
406
407# Additional ARCH settings for parisc
408ifeq ($(ARCH),parisc64)
409       SRCARCH := parisc
410endif
411
412export cross_compiling :=
413ifneq ($(SRCARCH),$(SUBARCH))
414cross_compiling := 1
415endif
416
417KCONFIG_CONFIG	?= .config
418export KCONFIG_CONFIG
419
420# SHELL used by kbuild
421CONFIG_SHELL := sh
422
423HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
424HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
425HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
426
427ifneq ($(LLVM),)
428HOSTCC	= clang
429HOSTCXX	= clang++
430else
431HOSTCC	= gcc
432HOSTCXX	= g++
433endif
434
435export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
436			      -O2 -fomit-frame-pointer -std=gnu89
437export KBUILD_USERLDFLAGS :=
438
439KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
440KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
441KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
442KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
443
444# Make variables (CC, etc...)
445CPP		= $(CC) -E
446ifneq ($(LLVM),)
447CC		= clang
448LD		= ld.lld
449AR		= llvm-ar
450NM		= llvm-nm
451OBJCOPY		= llvm-objcopy
452OBJDUMP		= llvm-objdump
453READELF		= llvm-readelf
454STRIP		= llvm-strip
455else
456CC		= $(CROSS_COMPILE)gcc
457LD		= $(CROSS_COMPILE)ld
458AR		= $(CROSS_COMPILE)ar
459NM		= $(CROSS_COMPILE)nm
460OBJCOPY		= $(CROSS_COMPILE)objcopy
461OBJDUMP		= $(CROSS_COMPILE)objdump
462READELF		= $(CROSS_COMPILE)readelf
463STRIP		= $(CROSS_COMPILE)strip
464endif
465PAHOLE		= pahole
466RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
467LEX		= flex
468YACC		= bison
469AWK		= awk
470INSTALLKERNEL  := installkernel
471DEPMOD		= depmod
472PERL		= perl
473PYTHON3		= python3
474CHECK		= sparse
475BASH		= bash
476KGZIP		= gzip
477KBZIP2		= bzip2
478KLZOP		= lzop
479LZMA		= lzma
480LZ4		= lz4c
481XZ		= xz
482ZSTD		= zstd
483
484CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
485		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
486NOSTDINC_FLAGS :=
487CFLAGS_MODULE   =
488AFLAGS_MODULE   =
489LDFLAGS_MODULE  =
490CFLAGS_KERNEL	=
491AFLAGS_KERNEL	=
492LDFLAGS_vmlinux =
493
494# Use USERINCLUDE when you must reference the UAPI directories only.
495USERINCLUDE    := \
496		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
497		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
498		-I$(srctree)/include/uapi \
499		-I$(objtree)/include/generated/uapi \
500                -include $(srctree)/include/linux/compiler-version.h \
501                -include $(srctree)/include/linux/kconfig.h
502
503# Use LINUXINCLUDE when you must reference the include/ directory.
504# Needed to be compatible with the O= option
505LINUXINCLUDE    := \
506		-I$(srctree)/arch/$(SRCARCH)/include \
507		-I$(objtree)/arch/$(SRCARCH)/include/generated \
508		$(if $(building_out_of_srctree),-I$(srctree)/include) \
509		-I$(objtree)/include \
510		$(USERINCLUDE)
511
512KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
513KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
514		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
515		   -Werror=implicit-function-declaration -Werror=implicit-int \
516		   -Werror=return-type -Wno-format-security \
517		   -std=gnu89
518KBUILD_CPPFLAGS := -D__KERNEL__
519KBUILD_AFLAGS_KERNEL :=
520KBUILD_CFLAGS_KERNEL :=
521KBUILD_AFLAGS_MODULE  := -DMODULE
522KBUILD_CFLAGS_MODULE  := -DMODULE
523KBUILD_LDFLAGS_MODULE :=
524KBUILD_LDFLAGS :=
525CLANG_FLAGS :=
526
527export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
528export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
529export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
530export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
531export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
532
533export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
534export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
535export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
536export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
537export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
538
539# Files to ignore in find ... statements
540
541export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
542			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
543			  -prune -o
544export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
545			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
546
547# ===========================================================================
548# Rules shared between *config targets and build targets
549
550# Basic helpers built in scripts/basic/
551PHONY += scripts_basic
552scripts_basic:
553	$(Q)$(MAKE) $(build)=scripts/basic
554
555PHONY += outputmakefile
556ifdef building_out_of_srctree
557# Before starting out-of-tree build, make sure the source tree is clean.
558# outputmakefile generates a Makefile in the output directory, if using a
559# separate output directory. This allows convenient use of make in the
560# output directory.
561# At the same time when output Makefile generated, generate .gitignore to
562# ignore whole output directory
563
564quiet_cmd_makefile = GEN     Makefile
565      cmd_makefile = { \
566	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
567	echo "include $(srctree)/Makefile"; \
568	} > Makefile
569
570outputmakefile:
571	$(Q)if [ -f $(srctree)/.config -o \
572		 -d $(srctree)/include/config -o \
573		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
574		echo >&2 "***"; \
575		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
576		echo >&2 "*** in $(abs_srctree)";\
577		echo >&2 "***"; \
578		false; \
579	fi
580	$(Q)ln -fsn $(srctree) source
581	$(call cmd,makefile)
582	$(Q)test -e .gitignore || \
583	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
584endif
585
586# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
587# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
588# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
589# and from include/config/auto.conf.cmd to detect the compiler upgrade.
590CC_VERSION_TEXT = $(subst $(pound),,$(shell $(CC) --version 2>/dev/null | head -n 1))
591
592ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
593ifneq ($(CROSS_COMPILE),)
594CLANG_FLAGS	+= --target=$(notdir $(CROSS_COMPILE:%-=%))
595endif
596ifeq ($(LLVM_IAS),1)
597CLANG_FLAGS	+= -integrated-as
598else
599CLANG_FLAGS	+= -no-integrated-as
600GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
601CLANG_FLAGS	+= --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
602endif
603CLANG_FLAGS	+= -Werror=unknown-warning-option
604KBUILD_CFLAGS	+= $(CLANG_FLAGS)
605KBUILD_AFLAGS	+= $(CLANG_FLAGS)
606export CLANG_FLAGS
607endif
608
609# Include this also for config targets because some architectures need
610# cc-cross-prefix to determine CROSS_COMPILE.
611ifdef need-compiler
612include $(srctree)/scripts/Makefile.compiler
613endif
614
615ifdef config-build
616# ===========================================================================
617# *config targets only - make sure prerequisites are updated, and descend
618# in scripts/kconfig to make the *config target
619
620# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
621# KBUILD_DEFCONFIG may point out an alternative default configuration
622# used for 'make defconfig'
623include $(srctree)/arch/$(SRCARCH)/Makefile
624export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
625
626config: outputmakefile scripts_basic FORCE
627	$(Q)$(MAKE) $(build)=scripts/kconfig $@
628
629%config: outputmakefile scripts_basic FORCE
630	$(Q)$(MAKE) $(build)=scripts/kconfig $@
631
632else #!config-build
633# ===========================================================================
634# Build targets only - this includes vmlinux, arch specific targets, clean
635# targets and others. In general all targets except *config targets.
636
637# If building an external module we do not care about the all: rule
638# but instead __all depend on modules
639PHONY += all
640ifeq ($(KBUILD_EXTMOD),)
641__all: all
642else
643__all: modules
644endif
645
646# Decide whether to build built-in, modular, or both.
647# Normally, just do built-in.
648
649KBUILD_MODULES :=
650KBUILD_BUILTIN := 1
651
652# If we have only "make modules", don't compile built-in objects.
653ifeq ($(MAKECMDGOALS),modules)
654  KBUILD_BUILTIN :=
655endif
656
657# If we have "make <whatever> modules", compile modules
658# in addition to whatever we do anyway.
659# Just "make" or "make all" shall build modules as well
660
661ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
662  KBUILD_MODULES := 1
663endif
664
665ifeq ($(MAKECMDGOALS),)
666  KBUILD_MODULES := 1
667endif
668
669export KBUILD_MODULES KBUILD_BUILTIN
670
671ifdef need-config
672include include/config/auto.conf
673endif
674
675ifeq ($(KBUILD_EXTMOD),)
676# Objects we will link into vmlinux / subdirs we need to visit
677core-y		:= init/ usr/ arch/$(SRCARCH)/
678drivers-y	:= drivers/ sound/
679drivers-$(CONFIG_SAMPLES) += samples/
680drivers-$(CONFIG_NET) += net/
681drivers-y	+= virt/
682libs-y		:= lib/
683endif # KBUILD_EXTMOD
684
685# The all: target is the default when no target is given on the
686# command line.
687# This allow a user to issue only 'make' to build a kernel including modules
688# Defaults to vmlinux, but the arch makefile usually adds further targets
689all: vmlinux
690
691CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage \
692	$(call cc-option,-fno-tree-loop-im) \
693	$(call cc-disable-warning,maybe-uninitialized,)
694export CFLAGS_GCOV
695
696# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
697ifdef CONFIG_FUNCTION_TRACER
698  CC_FLAGS_FTRACE := -pg
699endif
700
701RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
702RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
703RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
704RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
705RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
706RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
707export RETPOLINE_CFLAGS
708export RETPOLINE_VDSO_CFLAGS
709
710include $(srctree)/arch/$(SRCARCH)/Makefile
711
712ifdef need-config
713ifdef may-sync-config
714# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
715# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
716# because some architectures define CROSS_COMPILE there.
717include include/config/auto.conf.cmd
718
719$(KCONFIG_CONFIG):
720	@echo >&2 '***'
721	@echo >&2 '*** Configuration file "$@" not found!'
722	@echo >&2 '***'
723	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
724	@echo >&2 '*** "make menuconfig" or "make xconfig").'
725	@echo >&2 '***'
726	@/bin/false
727
728# The actual configuration files used during the build are stored in
729# include/generated/ and include/config/. Update them if .config is newer than
730# include/config/auto.conf (which mirrors .config).
731#
732# This exploits the 'multi-target pattern rule' trick.
733# The syncconfig should be executed only once to make all the targets.
734# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
735#
736# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
737# so you cannot notice that Kconfig is waiting for the user input.
738%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
739	$(Q)$(kecho) "  SYNC    $@"
740	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
741else # !may-sync-config
742# External modules and some install targets need include/generated/autoconf.h
743# and include/config/auto.conf but do not care if they are up-to-date.
744# Use auto.conf to trigger the test
745PHONY += include/config/auto.conf
746
747include/config/auto.conf:
748	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
749	echo >&2;							\
750	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
751	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
752	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
753	echo >&2 ;							\
754	/bin/false)
755
756endif # may-sync-config
757endif # need-config
758
759KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
760KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
761KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
762KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
763KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
764
765ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
766KBUILD_CFLAGS += -O2
767else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
768KBUILD_CFLAGS += -O3
769else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
770KBUILD_CFLAGS += -Os
771endif
772
773# Tell gcc to never replace conditional load with a non-conditional one
774KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
775KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
776
777ifdef CONFIG_READABLE_ASM
778# Disable optimizations that make assembler listings hard to read.
779# reorder blocks reorders the control in the function
780# ipa clone creates specialized cloned functions
781# partial inlining inlines only parts of functions
782KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
783                 $(call cc-option,-fno-ipa-cp-clone,) \
784                 $(call cc-option,-fno-partial-inlining)
785endif
786
787ifneq ($(CONFIG_FRAME_WARN),0)
788KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
789endif
790
791stackp-flags-y                                    := -fno-stack-protector
792stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
793stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
794
795KBUILD_CFLAGS += $(stackp-flags-y)
796
797ifdef CONFIG_CC_IS_CLANG
798KBUILD_CPPFLAGS += -Qunused-arguments
799KBUILD_CFLAGS += -Wno-format-invalid-specifier
800KBUILD_CFLAGS += -Wno-gnu
801# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
802# source of a reference will be _MergedGlobals and not on of the whitelisted names.
803# See modpost pattern 2
804KBUILD_CFLAGS += -mno-global-merge
805else
806
807# Warn about unmarked fall-throughs in switch statement.
808# Disabled for clang while comment to attribute conversion happens and
809# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
810KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,)
811endif
812
813# These warnings generated too much noise in a regular build.
814# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
815KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
816
817KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
818ifdef CONFIG_FRAME_POINTER
819KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
820else
821# Some targets (ARM with Thumb2, for example), can't be built with frame
822# pointers.  For those, we don't have FUNCTION_TRACER automatically
823# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
824# incompatible with -fomit-frame-pointer with current GCC, so we don't use
825# -fomit-frame-pointer with FUNCTION_TRACER.
826ifndef CONFIG_FUNCTION_TRACER
827KBUILD_CFLAGS	+= -fomit-frame-pointer
828endif
829endif
830
831# Initialize all stack variables with a 0xAA pattern.
832ifdef CONFIG_INIT_STACK_ALL_PATTERN
833KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
834endif
835
836# Initialize all stack variables with a zero value.
837ifdef CONFIG_INIT_STACK_ALL_ZERO
838# Future support for zero initialization is still being debated, see
839# https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
840# renamed or dropped.
841KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
842KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
843endif
844
845# While VLAs have been removed, GCC produces unreachable stack probes
846# for the randomize_kstack_offset feature. Disable it for all compilers.
847KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
848
849# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
850ifdef CONFIG_ZERO_CALL_USED_REGS
851KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
852endif
853
854DEBUG_CFLAGS	:=
855
856# Workaround for GCC versions < 5.0
857# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
858ifdef CONFIG_CC_IS_GCC
859DEBUG_CFLAGS	+= $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
860endif
861
862ifdef CONFIG_DEBUG_INFO
863
864ifdef CONFIG_DEBUG_INFO_SPLIT
865DEBUG_CFLAGS	+= -gsplit-dwarf
866else
867DEBUG_CFLAGS	+= -g
868endif
869
870ifneq ($(LLVM_IAS),1)
871KBUILD_AFLAGS	+= -Wa,-gdwarf-2
872endif
873
874ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
875dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
876dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
877DEBUG_CFLAGS	+= -gdwarf-$(dwarf-version-y)
878endif
879
880ifdef CONFIG_DEBUG_INFO_REDUCED
881DEBUG_CFLAGS	+= $(call cc-option, -femit-struct-debug-baseonly) \
882		   $(call cc-option,-fno-var-tracking)
883endif
884
885ifdef CONFIG_DEBUG_INFO_COMPRESSED
886DEBUG_CFLAGS	+= -gz=zlib
887KBUILD_AFLAGS	+= -gz=zlib
888KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
889endif
890
891endif # CONFIG_DEBUG_INFO
892
893KBUILD_CFLAGS += $(DEBUG_CFLAGS)
894export DEBUG_CFLAGS
895
896ifdef CONFIG_FUNCTION_TRACER
897ifdef CONFIG_FTRACE_MCOUNT_USE_CC
898  CC_FLAGS_FTRACE	+= -mrecord-mcount
899  ifdef CONFIG_HAVE_NOP_MCOUNT
900    ifeq ($(call cc-option-yn, -mnop-mcount),y)
901      CC_FLAGS_FTRACE	+= -mnop-mcount
902      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
903    endif
904  endif
905endif
906ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
907  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
908endif
909ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
910  ifdef CONFIG_HAVE_C_RECORDMCOUNT
911    BUILD_C_RECORDMCOUNT := y
912    export BUILD_C_RECORDMCOUNT
913  endif
914endif
915ifdef CONFIG_HAVE_FENTRY
916  ifeq ($(call cc-option-yn, -mfentry),y)
917    CC_FLAGS_FTRACE	+= -mfentry
918    CC_FLAGS_USING	+= -DCC_USING_FENTRY
919  endif
920endif
921export CC_FLAGS_FTRACE
922KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
923KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
924endif
925
926# We trigger additional mismatches with less inlining
927ifdef CONFIG_DEBUG_SECTION_MISMATCH
928KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
929endif
930
931ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
932KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
933LDFLAGS_vmlinux += --gc-sections
934endif
935
936ifdef CONFIG_SHADOW_CALL_STACK
937CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
938KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
939export CC_FLAGS_SCS
940endif
941
942ifdef CONFIG_LTO_CLANG
943ifdef CONFIG_LTO_CLANG_THIN
944CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
945KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
946else
947CC_FLAGS_LTO	:= -flto
948endif
949CC_FLAGS_LTO	+= -fvisibility=hidden
950
951# Limit inlining across translation units to reduce binary size
952KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
953
954# Check for frame size exceeding threshold during prolog/epilog insertion
955# when using lld < 13.0.0.
956ifneq ($(CONFIG_FRAME_WARN),0)
957ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
958KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
959endif
960endif
961endif
962
963ifdef CONFIG_LTO
964KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
965KBUILD_AFLAGS	+= -fno-lto
966export CC_FLAGS_LTO
967endif
968
969ifdef CONFIG_CFI_CLANG
970CC_FLAGS_CFI	:= -fsanitize=cfi \
971		   -fsanitize-cfi-cross-dso \
972		   -fno-sanitize-cfi-canonical-jump-tables \
973		   -fno-sanitize-trap=cfi \
974		   -fno-sanitize-blacklist
975
976ifdef CONFIG_CFI_PERMISSIVE
977CC_FLAGS_CFI	+= -fsanitize-recover=cfi
978endif
979
980# If LTO flags are filtered out, we must also filter out CFI.
981CC_FLAGS_LTO	+= $(CC_FLAGS_CFI)
982KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
983export CC_FLAGS_CFI
984endif
985
986ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
987KBUILD_CFLAGS += -falign-functions=64
988endif
989
990# arch Makefile may override CC so keep this after arch Makefile is included
991NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
992
993# warn about C99 declaration after statement
994KBUILD_CFLAGS += -Wdeclaration-after-statement
995
996# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
997KBUILD_CFLAGS += -Wvla
998
999# disable pointer signed / unsigned warnings in gcc 4.0
1000KBUILD_CFLAGS += -Wno-pointer-sign
1001
1002# disable stringop warnings in gcc 8+
1003KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1004
1005# We'll want to enable this eventually, but it's not going away for 5.7 at least
1006KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
1007KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
1008KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1009
1010# Another good warning that we'll want to enable eventually
1011KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1012
1013# Enabled with W=2, disabled by default as noisy
1014KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
1015
1016# disable invalid "can't wrap" optimizations for signed / pointers
1017KBUILD_CFLAGS	+= -fno-strict-overflow
1018
1019# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1020KBUILD_CFLAGS  += -fno-stack-check
1021
1022# conserve stack if available
1023KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
1024
1025# Prohibit date/time macros, which would make the build non-deterministic
1026KBUILD_CFLAGS   += -Werror=date-time
1027
1028# enforce correct pointer usage
1029KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1030
1031# Require designated initializers for all marked structures
1032KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1033
1034# change __FILE__ to the relative path from the srctree
1035KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1036
1037# include additional Makefiles when needed
1038include-y			:= scripts/Makefile.extrawarn
1039include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1040include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1041include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1042include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1043include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1044
1045include $(addprefix $(srctree)/, $(include-y))
1046
1047# scripts/Makefile.gcc-plugins is intentionally included last.
1048# Do not add $(call cc-option,...) below this line. When you build the kernel
1049# from the clean source tree, the GCC plugins do not exist at this point.
1050
1051# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1052KBUILD_CPPFLAGS += $(KCPPFLAGS)
1053KBUILD_AFLAGS   += $(KAFLAGS)
1054KBUILD_CFLAGS   += $(KCFLAGS)
1055
1056KBUILD_LDFLAGS_MODULE += --build-id=sha1
1057LDFLAGS_vmlinux += --build-id=sha1
1058
1059ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1060LDFLAGS_vmlinux	+= $(call ld-option, -X,)
1061endif
1062
1063ifeq ($(CONFIG_RELR),y)
1064LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1065endif
1066
1067# We never want expected sections to be placed heuristically by the
1068# linker. All sections should be explicitly named in the linker script.
1069ifdef CONFIG_LD_ORPHAN_WARN
1070LDFLAGS_vmlinux += --orphan-handling=warn
1071endif
1072
1073# Align the bit size of userspace programs with the kernel
1074KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1075KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1076
1077# make the checker run with the right architecture
1078CHECKFLAGS += --arch=$(ARCH)
1079
1080# insure the checker run with the right endianness
1081CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1082
1083# the checker needs the correct machine size
1084CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1085
1086# Default kernel image to build when no specific target is given.
1087# KBUILD_IMAGE may be overruled on the command line or
1088# set in the environment
1089# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1090# this default value
1091export KBUILD_IMAGE ?= vmlinux
1092
1093#
1094# INSTALL_PATH specifies where to place the updated kernel and system map
1095# images. Default is /boot, but you can set it to other values
1096export	INSTALL_PATH ?= /boot
1097
1098#
1099# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1100# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1101# an argument if needed. Otherwise it defaults to the kernel install path
1102#
1103export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1104
1105#
1106# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1107# relocations required by build roots.  This is not defined in the
1108# makefile but the argument can be passed to make if needed.
1109#
1110
1111MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1112export MODLIB
1113
1114PHONY += prepare0
1115
1116export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1117export MODORDER := $(extmod_prefix)modules.order
1118export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1119
1120ifeq ($(KBUILD_EXTMOD),)
1121core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1122
1123vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1124		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1125		     $(libs-y) $(libs-m)))
1126
1127vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1128		     $(patsubst %/,%,$(filter %/, $(core-) \
1129			$(drivers-) $(libs-))))
1130
1131subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1132			$(core-y) $(core-m) $(libs-y) $(libs-m) \
1133			$(drivers-y) $(drivers-m)))
1134
1135build-dirs	:= $(vmlinux-dirs)
1136clean-dirs	:= $(vmlinux-alldirs)
1137
1138# Externally visible symbols (used by link-vmlinux.sh)
1139KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1140KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1141ifdef CONFIG_MODULES
1142KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1143KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1144else
1145KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1146endif
1147KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1148
1149export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1150export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1151# used by scripts/Makefile.package
1152export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1153
1154vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1155
1156# Recurse until adjust_autoksyms.sh is satisfied
1157PHONY += autoksyms_recursive
1158ifdef CONFIG_TRIM_UNUSED_KSYMS
1159# For the kernel to actually contain only the needed exported symbols,
1160# we have to build modules as well to determine what those symbols are.
1161# (this can be evaluated only once include/config/auto.conf has been included)
1162KBUILD_MODULES := 1
1163
1164autoksyms_recursive: descend modules.order
1165	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1166	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1167endif
1168
1169autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1170
1171quiet_cmd_autoksyms_h = GEN     $@
1172      cmd_autoksyms_h = mkdir -p $(dir $@); \
1173			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1174
1175$(autoksyms_h):
1176	$(call cmd,autoksyms_h)
1177
1178ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1179
1180# Final link of vmlinux with optional arch pass after final link
1181cmd_link-vmlinux =                                                 \
1182	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1183	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1184
1185vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1186	+$(call if_changed_dep,link-vmlinux)
1187
1188targets := vmlinux
1189
1190# The actual objects are generated when descending,
1191# make sure no implicit rule kicks in
1192$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1193
1194filechk_kernel.release = \
1195	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1196
1197# Store (new) KERNELRELEASE string in include/config/kernel.release
1198include/config/kernel.release: FORCE
1199	$(call filechk,kernel.release)
1200
1201# Additional helpers built in scripts/
1202# Carefully list dependencies so we do not try to build scripts twice
1203# in parallel
1204PHONY += scripts
1205scripts: scripts_basic scripts_dtc
1206	$(Q)$(MAKE) $(build)=$(@)
1207
1208# Things we need to do before we recursively start building the kernel
1209# or the modules are listed in "prepare".
1210# A multi level approach is used. prepareN is processed before prepareN-1.
1211# archprepare is used in arch Makefiles and when processed asm symlink,
1212# version.h and scripts_basic is processed / created.
1213
1214PHONY += prepare archprepare
1215
1216archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1217	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1218	include/generated/autoconf.h remove-stale-files
1219
1220prepare0: archprepare
1221	$(Q)$(MAKE) $(build)=scripts/mod
1222	$(Q)$(MAKE) $(build)=.
1223
1224# All the preparing..
1225prepare: prepare0
1226
1227PHONY += remove-stale-files
1228remove-stale-files:
1229	$(Q)$(srctree)/scripts/remove-stale-files
1230
1231# Support for using generic headers in asm-generic
1232asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1233
1234PHONY += asm-generic uapi-asm-generic
1235asm-generic: uapi-asm-generic
1236	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1237	generic=include/asm-generic
1238uapi-asm-generic:
1239	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1240	generic=include/uapi/asm-generic
1241
1242# Generate some files
1243# ---------------------------------------------------------------------------
1244
1245# KERNELRELEASE can change from a few different places, meaning version.h
1246# needs to be updated, so this check is forced on all builds
1247
1248uts_len := 64
1249define filechk_utsrelease.h
1250	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1251	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1252	  exit 1;                                                         \
1253	fi;                                                               \
1254	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1255endef
1256
1257define filechk_version.h
1258	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1259		echo \#define LINUX_VERSION_CODE $(shell                 \
1260		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1261	else                                                             \
1262		echo \#define LINUX_VERSION_CODE $(shell                 \
1263		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1264	fi;                                                              \
1265	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1266	((c) > 255 ? 255 : (c)))';                                       \
1267	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1268	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1269	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1270endef
1271
1272$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1273$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1274$(version_h): FORCE
1275	$(call filechk,version.h)
1276
1277include/generated/utsrelease.h: include/config/kernel.release FORCE
1278	$(call filechk,utsrelease.h)
1279
1280PHONY += headerdep
1281headerdep:
1282	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1283	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1284
1285# ---------------------------------------------------------------------------
1286# Kernel headers
1287
1288#Default location for installed headers
1289export INSTALL_HDR_PATH = $(objtree)/usr
1290
1291quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1292      cmd_headers_install = \
1293	mkdir -p $(INSTALL_HDR_PATH); \
1294	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1295	usr/include $(INSTALL_HDR_PATH)
1296
1297PHONY += headers_install
1298headers_install: headers
1299	$(call cmd,headers_install)
1300
1301PHONY += archheaders archscripts
1302
1303hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1304
1305PHONY += headers
1306headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1307	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1308	  $(error Headers not exportable for the $(SRCARCH) architecture))
1309	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1310	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1311
1312# Deprecated. It is no-op now.
1313PHONY += headers_check
1314headers_check:
1315	@echo >&2 "=================== WARNING ==================="
1316	@echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1317	@echo >&2 "and will be removed after Linux 5.15 release."
1318	@echo >&2 "Please remove headers_check from your scripts."
1319	@echo >&2 "==============================================="
1320
1321ifdef CONFIG_HEADERS_INSTALL
1322prepare: headers
1323endif
1324
1325PHONY += scripts_unifdef
1326scripts_unifdef: scripts_basic
1327	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1328
1329# ---------------------------------------------------------------------------
1330# Install
1331
1332# Many distributions have the custom install script, /sbin/installkernel.
1333# If DKMS is installed, 'make install' will eventually recuses back
1334# to the this Makefile to build and install external modules.
1335# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1336
1337install: sub_make_done :=
1338
1339# ---------------------------------------------------------------------------
1340# Tools
1341
1342ifdef CONFIG_STACK_VALIDATION
1343prepare: tools/objtool
1344endif
1345
1346ifdef CONFIG_BPF
1347ifdef CONFIG_DEBUG_INFO_BTF
1348prepare: tools/bpf/resolve_btfids
1349endif
1350endif
1351
1352PHONY += resolve_btfids_clean
1353
1354resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1355
1356# tools/bpf/resolve_btfids directory might not exist
1357# in output directory, skip its clean in that case
1358resolve_btfids_clean:
1359ifneq ($(wildcard $(resolve_btfids_O)),)
1360	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1361endif
1362
1363# Clear a bunch of variables before executing the submake
1364ifeq ($(quiet),silent_)
1365tools_silent=s
1366endif
1367
1368tools/: FORCE
1369	$(Q)mkdir -p $(objtree)/tools
1370	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1371
1372tools/%: FORCE
1373	$(Q)mkdir -p $(objtree)/tools
1374	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1375
1376# ---------------------------------------------------------------------------
1377# Kernel selftest
1378
1379PHONY += kselftest
1380kselftest:
1381	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1382
1383kselftest-%: FORCE
1384	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1385
1386PHONY += kselftest-merge
1387kselftest-merge:
1388	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1389	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1390		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1391	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1392
1393# ---------------------------------------------------------------------------
1394# Devicetree files
1395
1396ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1397dtstree := arch/$(SRCARCH)/boot/dts
1398endif
1399
1400ifneq ($(dtstree),)
1401
1402%.dtb: include/config/kernel.release scripts_dtc
1403	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1404
1405%.dtbo: include/config/kernel.release scripts_dtc
1406	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1407
1408PHONY += dtbs dtbs_install dtbs_check
1409dtbs: include/config/kernel.release scripts_dtc
1410	$(Q)$(MAKE) $(build)=$(dtstree)
1411
1412ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1413export CHECK_DTBS=y
1414dtbs: dt_binding_check
1415endif
1416
1417dtbs_check: dtbs
1418
1419dtbs_install:
1420	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1421
1422ifdef CONFIG_OF_EARLY_FLATTREE
1423all: dtbs
1424endif
1425
1426endif
1427
1428PHONY += scripts_dtc
1429scripts_dtc: scripts_basic
1430	$(Q)$(MAKE) $(build)=scripts/dtc
1431
1432ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1433export CHECK_DT_BINDING=y
1434endif
1435
1436PHONY += dt_binding_check
1437dt_binding_check: scripts_dtc
1438	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1439
1440# ---------------------------------------------------------------------------
1441# Modules
1442
1443ifdef CONFIG_MODULES
1444
1445# By default, build modules as well
1446
1447all: modules
1448
1449# When we're building modules with modversions, we need to consider
1450# the built-in objects during the descend as well, in order to
1451# make sure the checksums are up to date before we record them.
1452ifdef CONFIG_MODVERSIONS
1453  KBUILD_BUILTIN := 1
1454endif
1455
1456# Build modules
1457#
1458# A module can be listed more than once in obj-m resulting in
1459# duplicate lines in modules.order files.  Those are removed
1460# using awk while concatenating to the final file.
1461
1462PHONY += modules
1463modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1464
1465cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1466
1467modules.order: $(subdir-modorder) FORCE
1468	$(call if_changed,modules_order)
1469
1470targets += modules.order
1471
1472# Target to prepare building external modules
1473PHONY += modules_prepare
1474modules_prepare: prepare
1475	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1476
1477export modules_sign_only :=
1478
1479ifeq ($(CONFIG_MODULE_SIG),y)
1480PHONY += modules_sign
1481modules_sign: modules_install
1482	@:
1483
1484# modules_sign is a subset of modules_install.
1485# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1486ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1487modules_sign_only := y
1488endif
1489endif
1490
1491modinst_pre :=
1492ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1493modinst_pre := __modinst_pre
1494endif
1495
1496modules_install: $(modinst_pre)
1497PHONY += __modinst_pre
1498__modinst_pre:
1499	@rm -rf $(MODLIB)/kernel
1500	@rm -f $(MODLIB)/source
1501	@mkdir -p $(MODLIB)/kernel
1502	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1503	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1504		rm -f $(MODLIB)/build ; \
1505		ln -s $(CURDIR) $(MODLIB)/build ; \
1506	fi
1507	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1508	@cp -f modules.builtin $(MODLIB)/
1509	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1510
1511endif # CONFIG_MODULES
1512
1513###
1514# Cleaning is done on three levels.
1515# make clean     Delete most generated files
1516#                Leave enough to build external modules
1517# make mrproper  Delete the current configuration, and all generated files
1518# make distclean Remove editor backup files, patch leftover files and the like
1519
1520# Directories & files removed with 'make clean'
1521CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1522	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1523	       compile_commands.json .thinlto-cache
1524
1525# Directories & files removed with 'make mrproper'
1526MRPROPER_FILES += include/config include/generated          \
1527		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1528		  debian snap tar-install \
1529		  .config .config.old .version \
1530		  Module.symvers \
1531		  certs/signing_key.pem certs/signing_key.x509 \
1532		  certs/x509.genkey \
1533		  vmlinux-gdb.py \
1534		  *.spec
1535
1536# clean - Delete most, but leave enough to build external modules
1537#
1538clean: rm-files := $(CLEAN_FILES)
1539
1540PHONY += archclean vmlinuxclean
1541
1542vmlinuxclean:
1543	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1544	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1545
1546clean: archclean vmlinuxclean resolve_btfids_clean
1547
1548# mrproper - Delete all generated files, including .config
1549#
1550mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1551mrproper-dirs      := $(addprefix _mrproper_,scripts)
1552
1553PHONY += $(mrproper-dirs) mrproper
1554$(mrproper-dirs):
1555	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1556
1557mrproper: clean $(mrproper-dirs)
1558	$(call cmd,rmfiles)
1559
1560# distclean
1561#
1562PHONY += distclean
1563
1564distclean: mrproper
1565	@find . $(RCS_FIND_IGNORE) \
1566		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1567		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1568		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1569		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1570		-type f -print | xargs rm -f
1571
1572
1573# Packaging of the kernel to various formats
1574# ---------------------------------------------------------------------------
1575
1576%src-pkg: FORCE
1577	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1578%pkg: include/config/kernel.release FORCE
1579	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1580
1581# Brief documentation of the typical targets used
1582# ---------------------------------------------------------------------------
1583
1584boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1585boards := $(sort $(notdir $(boards)))
1586board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1587board-dirs := $(sort $(notdir $(board-dirs:/=)))
1588
1589PHONY += help
1590help:
1591	@echo  'Cleaning targets:'
1592	@echo  '  clean		  - Remove most generated files but keep the config and'
1593	@echo  '                    enough build support to build external modules'
1594	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1595	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1596	@echo  ''
1597	@echo  'Configuration targets:'
1598	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1599	@echo  ''
1600	@echo  'Other generic targets:'
1601	@echo  '  all		  - Build all targets marked with [*]'
1602	@echo  '* vmlinux	  - Build the bare kernel'
1603	@echo  '* modules	  - Build all modules'
1604	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1605	@echo  '  dir/            - Build all files in dir and below'
1606	@echo  '  dir/file.[ois]  - Build specified target only'
1607	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1608	@echo  '                    (requires compiler support for LLVM assembly generation)'
1609	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1610	@echo  '                    (requires a recent binutils and recent build (System.map))'
1611	@echo  '  dir/file.ko     - Build module including final link'
1612	@echo  '  modules_prepare - Set up for building external modules'
1613	@echo  '  tags/TAGS	  - Generate tags file for editors'
1614	@echo  '  cscope	  - Generate cscope index'
1615	@echo  '  gtags           - Generate GNU GLOBAL index'
1616	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1617	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1618	@echo  '  image_name	  - Output the image name (use with make -s)'
1619	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1620	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1621	 echo  ''
1622	@echo  'Static analysers:'
1623	@echo  '  checkstack      - Generate a list of stack hogs'
1624	@echo  '  versioncheck    - Sanity check on version.h usage'
1625	@echo  '  includecheck    - Check for duplicate included header files'
1626	@echo  '  export_report   - List the usages of all exported symbols'
1627	@echo  '  headerdep       - Detect inclusion cycles in headers'
1628	@echo  '  coccicheck      - Check with Coccinelle'
1629	@echo  '  clang-analyzer  - Check with clang static analyzer'
1630	@echo  '  clang-tidy      - Check with clang-tidy'
1631	@echo  ''
1632	@echo  'Tools:'
1633	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1634	@echo  ''
1635	@echo  'Kernel selftest:'
1636	@echo  '  kselftest         - Build and run kernel selftest'
1637	@echo  '                      Build, install, and boot kernel before'
1638	@echo  '                      running kselftest on it'
1639	@echo  '                      Run as root for full coverage'
1640	@echo  '  kselftest-all     - Build kernel selftest'
1641	@echo  '  kselftest-install - Build and install kernel selftest'
1642	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1643	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1644	@echo  '		      kselftest to existing .config.'
1645	@echo  ''
1646	@$(if $(dtstree), \
1647		echo 'Devicetree:'; \
1648		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1649		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1650		echo '  dt_binding_check - Validate device tree binding documents'; \
1651		echo '  dtbs_check       - Validate device tree source files';\
1652		echo '')
1653
1654	@echo 'Userspace tools targets:'
1655	@echo '  use "make tools/help"'
1656	@echo '  or  "cd tools; make help"'
1657	@echo  ''
1658	@echo  'Kernel packaging:'
1659	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1660	@echo  ''
1661	@echo  'Documentation targets:'
1662	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1663	@echo  ''
1664	@echo  'Architecture specific targets ($(SRCARCH)):'
1665	@$(if $(archhelp),$(archhelp),\
1666		echo '  No architecture specific help defined for $(SRCARCH)')
1667	@echo  ''
1668	@$(if $(boards), \
1669		$(foreach b, $(boards), \
1670		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1671		echo '')
1672	@$(if $(board-dirs), \
1673		$(foreach b, $(board-dirs), \
1674		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1675		printf "  %-16s - Show all of the above\\n" help-boards; \
1676		echo '')
1677
1678	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1679	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1680	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1681	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1682	@echo  '                       (sparse by default)'
1683	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1684	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1685	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1686	@echo  '		1: warnings which may be relevant and do not occur too often'
1687	@echo  '		2: warnings which occur quite often but may still be relevant'
1688	@echo  '		3: more obscure warnings, can most likely be ignored'
1689	@echo  '		Multiple levels can be combined with W=12 or W=123'
1690	@echo  ''
1691	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1692	@echo  'For further info see the ./README file'
1693
1694
1695help-board-dirs := $(addprefix help-,$(board-dirs))
1696
1697help-boards: $(help-board-dirs)
1698
1699boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1700
1701$(help-board-dirs): help-%:
1702	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1703	@$(if $(boards-per-dir), \
1704		$(foreach b, $(boards-per-dir), \
1705		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1706		echo '')
1707
1708
1709# Documentation targets
1710# ---------------------------------------------------------------------------
1711DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1712	       linkcheckdocs dochelp refcheckdocs
1713PHONY += $(DOC_TARGETS)
1714$(DOC_TARGETS):
1715	$(Q)$(MAKE) $(build)=Documentation $@
1716
1717# Misc
1718# ---------------------------------------------------------------------------
1719
1720PHONY += scripts_gdb
1721scripts_gdb: prepare0
1722	$(Q)$(MAKE) $(build)=scripts/gdb
1723	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1724
1725ifdef CONFIG_GDB_SCRIPTS
1726all: scripts_gdb
1727endif
1728
1729else # KBUILD_EXTMOD
1730
1731###
1732# External module support.
1733# When building external modules the kernel used as basis is considered
1734# read-only, and no consistency checks are made and the make
1735# system is not used on the basis kernel. If updates are required
1736# in the basis kernel ordinary make commands (without M=...) must be used.
1737
1738# We are always building only modules.
1739KBUILD_BUILTIN :=
1740KBUILD_MODULES := 1
1741
1742build-dirs := $(KBUILD_EXTMOD)
1743$(MODORDER): descend
1744	@:
1745
1746compile_commands.json: $(extmod_prefix)compile_commands.json
1747PHONY += compile_commands.json
1748
1749clean-dirs := $(KBUILD_EXTMOD)
1750clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1751	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1752
1753PHONY += help
1754help:
1755	@echo  '  Building external modules.'
1756	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1757	@echo  ''
1758	@echo  '  modules         - default target, build the module(s)'
1759	@echo  '  modules_install - install the module'
1760	@echo  '  clean           - remove generated files in module directory only'
1761	@echo  ''
1762
1763# no-op for external module builds
1764PHONY += prepare modules_prepare
1765
1766endif # KBUILD_EXTMOD
1767
1768# ---------------------------------------------------------------------------
1769# Modules
1770
1771PHONY += modules modules_install
1772
1773ifdef CONFIG_MODULES
1774
1775modules: modules_check
1776	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1777
1778PHONY += modules_check
1779modules_check: $(MODORDER)
1780	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1781
1782quiet_cmd_depmod = DEPMOD  $(MODLIB)
1783      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1784                   $(KERNELRELEASE)
1785
1786modules_install:
1787	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1788	$(call cmd,depmod)
1789
1790else # CONFIG_MODULES
1791
1792# Modules not configured
1793# ---------------------------------------------------------------------------
1794
1795modules modules_install:
1796	@echo >&2 '***'
1797	@echo >&2 '*** The present kernel configuration has modules disabled.'
1798	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1799	@echo >&2 '*** to enable CONFIG_MODULES.'
1800	@echo >&2 '***'
1801	@exit 1
1802
1803endif # CONFIG_MODULES
1804
1805# Single targets
1806# ---------------------------------------------------------------------------
1807# To build individual files in subdirectories, you can do like this:
1808#
1809#   make foo/bar/baz.s
1810#
1811# The supported suffixes for single-target are listed in 'single-targets'
1812#
1813# To build only under specific subdirectories, you can do like this:
1814#
1815#   make foo/bar/baz/
1816
1817ifdef single-build
1818
1819# .ko is special because modpost is needed
1820single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1821single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1822
1823$(single-ko): single_modpost
1824	@:
1825$(single-no-ko): descend
1826	@:
1827
1828ifeq ($(KBUILD_EXTMOD),)
1829# For the single build of in-tree modules, use a temporary file to avoid
1830# the situation of modules_install installing an invalid modules.order.
1831MODORDER := .modules.tmp
1832endif
1833
1834PHONY += single_modpost
1835single_modpost: $(single-no-ko) modules_prepare
1836	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1837	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1838
1839KBUILD_MODULES := 1
1840
1841export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1842
1843# trim unrelated directories
1844build-dirs := $(foreach d, $(build-dirs), \
1845			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1846
1847endif
1848
1849ifndef CONFIG_MODULES
1850KBUILD_MODULES :=
1851endif
1852
1853# Handle descending into subdirectories listed in $(build-dirs)
1854# Preset locale variables to speed up the build process. Limit locale
1855# tweaks to this spot to avoid wrong language settings when running
1856# make menuconfig etc.
1857# Error messages still appears in the original language
1858PHONY += descend $(build-dirs)
1859descend: $(build-dirs)
1860$(build-dirs): prepare
1861	$(Q)$(MAKE) $(build)=$@ \
1862	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1863	need-builtin=1 need-modorder=1
1864
1865clean-dirs := $(addprefix _clean_, $(clean-dirs))
1866PHONY += $(clean-dirs) clean
1867$(clean-dirs):
1868	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1869
1870clean: $(clean-dirs)
1871	$(call cmd,rmfiles)
1872	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1873		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1874		-o -name '*.ko.*' \
1875		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1876		-o -name '*.dwo' -o -name '*.lst' \
1877		-o -name '*.su' -o -name '*.mod' \
1878		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1879		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1880		-o -name '*.asn1.[ch]' \
1881		-o -name '*.symtypes' -o -name 'modules.order' \
1882		-o -name '.tmp_*.o.*' \
1883		-o -name '*.c.[012]*.*' \
1884		-o -name '*.ll' \
1885		-o -name '*.gcno' \
1886		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
1887
1888# Generate tags for editors
1889# ---------------------------------------------------------------------------
1890quiet_cmd_tags = GEN     $@
1891      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1892
1893tags TAGS cscope gtags: FORCE
1894	$(call cmd,tags)
1895
1896# Script to generate missing namespace dependencies
1897# ---------------------------------------------------------------------------
1898
1899PHONY += nsdeps
1900nsdeps: export KBUILD_NSDEPS=1
1901nsdeps: modules
1902	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1903
1904# Clang Tooling
1905# ---------------------------------------------------------------------------
1906
1907quiet_cmd_gen_compile_commands = GEN     $@
1908      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1909
1910$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1911	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1912	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1913	$(call if_changed,gen_compile_commands)
1914
1915targets += $(extmod_prefix)compile_commands.json
1916
1917PHONY += clang-tidy clang-analyzer
1918
1919ifdef CONFIG_CC_IS_CLANG
1920quiet_cmd_clang_tools = CHECK   $<
1921      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1922
1923clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1924	$(call cmd,clang_tools)
1925else
1926clang-tidy clang-analyzer:
1927	@echo "$@ requires CC=clang" >&2
1928	@false
1929endif
1930
1931# Scripts to check various things for consistency
1932# ---------------------------------------------------------------------------
1933
1934PHONY += includecheck versioncheck coccicheck export_report
1935
1936includecheck:
1937	find $(srctree)/* $(RCS_FIND_IGNORE) \
1938		-name '*.[hcS]' -type f -print | sort \
1939		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1940
1941versioncheck:
1942	find $(srctree)/* $(RCS_FIND_IGNORE) \
1943		-name '*.[hcS]' -type f -print | sort \
1944		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1945
1946coccicheck:
1947	$(Q)$(BASH) $(srctree)/scripts/$@
1948
1949export_report:
1950	$(PERL) $(srctree)/scripts/export_report.pl
1951
1952PHONY += checkstack kernelrelease kernelversion image_name
1953
1954# UML needs a little special treatment here.  It wants to use the host
1955# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1956# else wants $(ARCH), including people doing cross-builds, which means
1957# that $(SUBARCH) doesn't work here.
1958ifeq ($(ARCH), um)
1959CHECKSTACK_ARCH := $(SUBARCH)
1960else
1961CHECKSTACK_ARCH := $(ARCH)
1962endif
1963checkstack:
1964	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1965	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1966
1967kernelrelease:
1968	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1969
1970kernelversion:
1971	@echo $(KERNELVERSION)
1972
1973image_name:
1974	@echo $(KBUILD_IMAGE)
1975
1976quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1977      cmd_rmfiles = rm -rf $(rm-files)
1978
1979# read saved command lines for existing targets
1980existing-targets := $(wildcard $(sort $(targets)))
1981
1982-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1983
1984endif # config-build
1985endif # mixed-build
1986endif # need-sub-make
1987
1988PHONY += FORCE
1989FORCE:
1990
1991# Declare the contents of the PHONY variable as phony.  We keep that
1992# information in a variable so we can use it in if_changed and friends.
1993.PHONY: $(PHONY)
1994