xref: /linux/Makefile (revision dee2b702)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 15
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Trick or Treat
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# --included-dir is added for backward compatibility, but you should not rely on
195# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
196MAKEFLAGS += --include-dir=$(abs_srctree)
197endif
198
199ifneq ($(filter 3.%,$(MAKE_VERSION)),)
200# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
201# We need to invoke sub-make to avoid implicit rules in the top Makefile.
202need-sub-make := 1
203# Cancel implicit rules for this Makefile.
204$(this-makefile): ;
205endif
206
207export abs_srctree abs_objtree
208export sub_make_done := 1
209
210ifeq ($(need-sub-make),1)
211
212PHONY += $(MAKECMDGOALS) __sub-make
213
214$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
215	@:
216
217# Invoke a second make in the output directory, passing relevant variables
218__sub-make:
219	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
220
221endif # need-sub-make
222endif # sub_make_done
223
224# We process the rest of the Makefile if this is the final invocation of make
225ifeq ($(need-sub-make),)
226
227# Do not print "Entering directory ...",
228# but we want to display it when entering to the output directory
229# so that IDEs/editors are able to understand relative filenames.
230MAKEFLAGS += --no-print-directory
231
232ifeq ($(abs_srctree),$(abs_objtree))
233        # building in the source tree
234        srctree := .
235	building_out_of_srctree :=
236else
237        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
238                # building in a subdirectory of the source tree
239                srctree := ..
240        else
241                srctree := $(abs_srctree)
242        endif
243	building_out_of_srctree := 1
244endif
245
246ifneq ($(KBUILD_ABS_SRCTREE),)
247srctree := $(abs_srctree)
248endif
249
250objtree		:= .
251VPATH		:= $(srctree)
252
253export building_out_of_srctree srctree objtree VPATH
254
255# To make sure we do not include .config for any of the *config targets
256# catch them early, and hand them over to scripts/kconfig/Makefile
257# It is allowed to specify more targets when calling make, including
258# mixing *config targets and build targets.
259# For example 'make oldconfig all'.
260# Detect when mixed targets is specified, and make a second invocation
261# of make so .config is not included in this case either (for *config).
262
263version_h := include/generated/uapi/linux/version.h
264
265clean-targets := %clean mrproper cleandocs
266no-dot-config-targets := $(clean-targets) \
267			 cscope gtags TAGS tags help% %docs check% coccicheck \
268			 $(version_h) headers headers_% archheaders archscripts \
269			 %asm-generic kernelversion %src-pkg dt_binding_check \
270			 outputmakefile
271# Installation targets should not require compiler. Unfortunately, vdso_install
272# is an exception where build artifacts may be updated. This must be fixed.
273no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
274			headers_install modules_install kernelrelease image_name
275no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
276			  image_name
277single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
278
279config-build	:=
280mixed-build	:=
281need-config	:= 1
282need-compiler	:= 1
283may-sync-config	:= 1
284single-build	:=
285
286ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
287	ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
288		need-config :=
289	endif
290endif
291
292ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
293	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
294		need-compiler :=
295	endif
296endif
297
298ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
299	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
300		may-sync-config :=
301	endif
302endif
303
304ifneq ($(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 = $(shell cat include/config/kernel.release 2> /dev/null)
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=ia64
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=ia64-linux-
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),)
427HOSTCC	= clang
428HOSTCXX	= clang++
429else
430HOSTCC	= gcc
431HOSTCXX	= g++
432endif
433
434export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
435			      -O2 -fomit-frame-pointer -std=gnu89
436export KBUILD_USERLDFLAGS :=
437
438KBUILD_HOSTCFLAGS   := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
439KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
440KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
441KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
442
443# Make variables (CC, etc...)
444CPP		= $(CC) -E
445ifneq ($(LLVM),)
446CC		= clang
447LD		= ld.lld
448AR		= llvm-ar
449NM		= llvm-nm
450OBJCOPY		= llvm-objcopy
451OBJDUMP		= llvm-objdump
452READELF		= llvm-readelf
453STRIP		= llvm-strip
454else
455CC		= $(CROSS_COMPILE)gcc
456LD		= $(CROSS_COMPILE)ld
457AR		= $(CROSS_COMPILE)ar
458NM		= $(CROSS_COMPILE)nm
459OBJCOPY		= $(CROSS_COMPILE)objcopy
460OBJDUMP		= $(CROSS_COMPILE)objdump
461READELF		= $(CROSS_COMPILE)readelf
462STRIP		= $(CROSS_COMPILE)strip
463endif
464PAHOLE		= pahole
465RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
466LEX		= flex
467YACC		= bison
468AWK		= awk
469INSTALLKERNEL  := installkernel
470DEPMOD		= depmod
471PERL		= perl
472PYTHON3		= python3
473CHECK		= sparse
474BASH		= bash
475KGZIP		= gzip
476KBZIP2		= bzip2
477KLZOP		= lzop
478LZMA		= lzma
479LZ4		= lz4c
480XZ		= xz
481ZSTD		= zstd
482
483PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
484
485CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
486		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
487NOSTDINC_FLAGS :=
488CFLAGS_MODULE   =
489AFLAGS_MODULE   =
490LDFLAGS_MODULE  =
491CFLAGS_KERNEL	=
492AFLAGS_KERNEL	=
493LDFLAGS_vmlinux =
494
495# Use USERINCLUDE when you must reference the UAPI directories only.
496USERINCLUDE    := \
497		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
498		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
499		-I$(srctree)/include/uapi \
500		-I$(objtree)/include/generated/uapi \
501                -include $(srctree)/include/linux/compiler-version.h \
502                -include $(srctree)/include/linux/kconfig.h
503
504# Use LINUXINCLUDE when you must reference the include/ directory.
505# Needed to be compatible with the O= option
506LINUXINCLUDE    := \
507		-I$(srctree)/arch/$(SRCARCH)/include \
508		-I$(objtree)/arch/$(SRCARCH)/include/generated \
509		$(if $(building_out_of_srctree),-I$(srctree)/include) \
510		-I$(objtree)/include \
511		$(USERINCLUDE)
512
513KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
514KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
515		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
516		   -Werror=implicit-function-declaration -Werror=implicit-int \
517		   -Werror=return-type -Wno-format-security \
518		   -std=gnu89
519KBUILD_CPPFLAGS := -D__KERNEL__
520KBUILD_AFLAGS_KERNEL :=
521KBUILD_CFLAGS_KERNEL :=
522KBUILD_AFLAGS_MODULE  := -DMODULE
523KBUILD_CFLAGS_MODULE  := -DMODULE
524KBUILD_LDFLAGS_MODULE :=
525KBUILD_LDFLAGS :=
526CLANG_FLAGS :=
527
528export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
529export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
530export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
531export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
532export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
533
534export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
535export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
536export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
537export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
538export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
539export PAHOLE_FLAGS
540
541# Files to ignore in find ... statements
542
543export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
544			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
545			  -prune -o
546export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
547			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
548
549# ===========================================================================
550# Rules shared between *config targets and build targets
551
552# Basic helpers built in scripts/basic/
553PHONY += scripts_basic
554scripts_basic:
555	$(Q)$(MAKE) $(build)=scripts/basic
556
557PHONY += outputmakefile
558ifdef building_out_of_srctree
559# Before starting out-of-tree build, make sure the source tree is clean.
560# outputmakefile generates a Makefile in the output directory, if using a
561# separate output directory. This allows convenient use of make in the
562# output directory.
563# At the same time when output Makefile generated, generate .gitignore to
564# ignore whole output directory
565
566quiet_cmd_makefile = GEN     Makefile
567      cmd_makefile = { \
568	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
569	echo "include $(srctree)/Makefile"; \
570	} > Makefile
571
572outputmakefile:
573	$(Q)if [ -f $(srctree)/.config -o \
574		 -d $(srctree)/include/config -o \
575		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
576		echo >&2 "***"; \
577		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
578		echo >&2 "*** in $(abs_srctree)";\
579		echo >&2 "***"; \
580		false; \
581	fi
582	$(Q)ln -fsn $(srctree) source
583	$(call cmd,makefile)
584	$(Q)test -e .gitignore || \
585	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
586endif
587
588# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
589# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
590# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
591# and from include/config/auto.conf.cmd to detect the compiler upgrade.
592CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
593
594ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
595include $(srctree)/scripts/Makefile.clang
596endif
597
598# Include this also for config targets because some architectures need
599# cc-cross-prefix to determine CROSS_COMPILE.
600ifdef need-compiler
601include $(srctree)/scripts/Makefile.compiler
602endif
603
604ifdef config-build
605# ===========================================================================
606# *config targets only - make sure prerequisites are updated, and descend
607# in scripts/kconfig to make the *config target
608
609# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
610# KBUILD_DEFCONFIG may point out an alternative default configuration
611# used for 'make defconfig'
612include $(srctree)/arch/$(SRCARCH)/Makefile
613export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
614
615config: outputmakefile scripts_basic FORCE
616	$(Q)$(MAKE) $(build)=scripts/kconfig $@
617
618%config: outputmakefile scripts_basic FORCE
619	$(Q)$(MAKE) $(build)=scripts/kconfig $@
620
621else #!config-build
622# ===========================================================================
623# Build targets only - this includes vmlinux, arch specific targets, clean
624# targets and others. In general all targets except *config targets.
625
626# If building an external module we do not care about the all: rule
627# but instead __all depend on modules
628PHONY += all
629ifeq ($(KBUILD_EXTMOD),)
630__all: all
631else
632__all: modules
633endif
634
635# Decide whether to build built-in, modular, or both.
636# Normally, just do built-in.
637
638KBUILD_MODULES :=
639KBUILD_BUILTIN := 1
640
641# If we have only "make modules", don't compile built-in objects.
642ifeq ($(MAKECMDGOALS),modules)
643  KBUILD_BUILTIN :=
644endif
645
646# If we have "make <whatever> modules", compile modules
647# in addition to whatever we do anyway.
648# Just "make" or "make all" shall build modules as well
649
650ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
651  KBUILD_MODULES := 1
652endif
653
654ifeq ($(MAKECMDGOALS),)
655  KBUILD_MODULES := 1
656endif
657
658export KBUILD_MODULES KBUILD_BUILTIN
659
660ifdef need-config
661include include/config/auto.conf
662endif
663
664ifeq ($(KBUILD_EXTMOD),)
665# Objects we will link into vmlinux / subdirs we need to visit
666core-y		:= init/ usr/ arch/$(SRCARCH)/
667drivers-y	:= drivers/ sound/
668drivers-$(CONFIG_SAMPLES) += samples/
669drivers-$(CONFIG_NET) += net/
670drivers-y	+= virt/
671libs-y		:= lib/
672endif # KBUILD_EXTMOD
673
674# The all: target is the default when no target is given on the
675# command line.
676# This allow a user to issue only 'make' to build a kernel including modules
677# Defaults to vmlinux, but the arch makefile usually adds further targets
678all: vmlinux
679
680CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
681ifdef CONFIG_CC_IS_GCC
682CFLAGS_GCOV	+= -fno-tree-loop-im
683endif
684export CFLAGS_GCOV
685
686# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
687ifdef CONFIG_FUNCTION_TRACER
688  CC_FLAGS_FTRACE := -pg
689endif
690
691ifdef CONFIG_CC_IS_GCC
692RETPOLINE_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
693RETPOLINE_VDSO_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
694endif
695ifdef CONFIG_CC_IS_CLANG
696RETPOLINE_CFLAGS	:= -mretpoline-external-thunk
697RETPOLINE_VDSO_CFLAGS	:= -mretpoline
698endif
699export RETPOLINE_CFLAGS
700export RETPOLINE_VDSO_CFLAGS
701
702include $(srctree)/arch/$(SRCARCH)/Makefile
703
704ifdef need-config
705ifdef may-sync-config
706# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
707# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
708# because some architectures define CROSS_COMPILE there.
709include include/config/auto.conf.cmd
710
711$(KCONFIG_CONFIG):
712	@echo >&2 '***'
713	@echo >&2 '*** Configuration file "$@" not found!'
714	@echo >&2 '***'
715	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
716	@echo >&2 '*** "make menuconfig" or "make xconfig").'
717	@echo >&2 '***'
718	@/bin/false
719
720# The actual configuration files used during the build are stored in
721# include/generated/ and include/config/. Update them if .config is newer than
722# include/config/auto.conf (which mirrors .config).
723#
724# This exploits the 'multi-target pattern rule' trick.
725# The syncconfig should be executed only once to make all the targets.
726# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
727#
728# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
729# so you cannot notice that Kconfig is waiting for the user input.
730%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
731	$(Q)$(kecho) "  SYNC    $@"
732	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
733else # !may-sync-config
734# External modules and some install targets need include/generated/autoconf.h
735# and include/config/auto.conf but do not care if they are up-to-date.
736# Use auto.conf to trigger the test
737PHONY += include/config/auto.conf
738
739include/config/auto.conf:
740	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
741	echo >&2;							\
742	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
743	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
744	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
745	echo >&2 ;							\
746	/bin/false)
747
748endif # may-sync-config
749endif # need-config
750
751KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
752KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
753KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
754KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
755KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
756
757ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
758KBUILD_CFLAGS += -O2
759else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
760KBUILD_CFLAGS += -O3
761else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
762KBUILD_CFLAGS += -Os
763endif
764
765# Tell gcc to never replace conditional load with a non-conditional one
766ifdef CONFIG_CC_IS_GCC
767# gcc-10 renamed --param=allow-store-data-races=0 to
768# -fno-allow-store-data-races.
769KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
770KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
771endif
772
773ifdef CONFIG_READABLE_ASM
774# Disable optimizations that make assembler listings hard to read.
775# reorder blocks reorders the control in the function
776# ipa clone creates specialized cloned functions
777# partial inlining inlines only parts of functions
778KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
779endif
780
781ifneq ($(CONFIG_FRAME_WARN),0)
782KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
783endif
784
785stackp-flags-y                                    := -fno-stack-protector
786stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
787stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
788
789KBUILD_CFLAGS += $(stackp-flags-y)
790
791KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
792KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
793
794ifdef CONFIG_CC_IS_CLANG
795KBUILD_CPPFLAGS += -Qunused-arguments
796# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable.
797KBUILD_CFLAGS += -Wno-gnu
798# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
799# source of a reference will be _MergedGlobals and not on of the whitelisted names.
800# See modpost pattern 2
801KBUILD_CFLAGS += -mno-global-merge
802else
803
804# gcc inanely warns about local variables called 'main'
805KBUILD_CFLAGS += -Wno-main
806endif
807
808# These warnings generated too much noise in a regular build.
809# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
810KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
811KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
812
813ifdef CONFIG_FRAME_POINTER
814KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
815else
816# Some targets (ARM with Thumb2, for example), can't be built with frame
817# pointers.  For those, we don't have FUNCTION_TRACER automatically
818# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
819# incompatible with -fomit-frame-pointer with current GCC, so we don't use
820# -fomit-frame-pointer with FUNCTION_TRACER.
821ifndef CONFIG_FUNCTION_TRACER
822KBUILD_CFLAGS	+= -fomit-frame-pointer
823endif
824endif
825
826# Initialize all stack variables with a 0xAA pattern.
827ifdef CONFIG_INIT_STACK_ALL_PATTERN
828KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
829endif
830
831# Initialize all stack variables with a zero value.
832ifdef CONFIG_INIT_STACK_ALL_ZERO
833KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
834ifdef CONFIG_CC_IS_CLANG
835# https://bugs.llvm.org/show_bug.cgi?id=45497
836KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
837endif
838endif
839
840# While VLAs have been removed, GCC produces unreachable stack probes
841# for the randomize_kstack_offset feature. Disable it for all compilers.
842KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
843
844# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
845ifdef CONFIG_ZERO_CALL_USED_REGS
846KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
847endif
848
849ifdef CONFIG_FUNCTION_TRACER
850ifdef CONFIG_FTRACE_MCOUNT_USE_CC
851  CC_FLAGS_FTRACE	+= -mrecord-mcount
852  ifdef CONFIG_HAVE_NOP_MCOUNT
853    ifeq ($(call cc-option-yn, -mnop-mcount),y)
854      CC_FLAGS_FTRACE	+= -mnop-mcount
855      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
856    endif
857  endif
858endif
859ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
860  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
861endif
862ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
863  ifdef CONFIG_HAVE_C_RECORDMCOUNT
864    BUILD_C_RECORDMCOUNT := y
865    export BUILD_C_RECORDMCOUNT
866  endif
867endif
868ifdef CONFIG_HAVE_FENTRY
869  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
870  ifeq ($(call cc-option-yn, -mfentry),y)
871    CC_FLAGS_FTRACE	+= -mfentry
872    CC_FLAGS_USING	+= -DCC_USING_FENTRY
873  endif
874endif
875export CC_FLAGS_FTRACE
876KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
877KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
878endif
879
880# We trigger additional mismatches with less inlining
881ifdef CONFIG_DEBUG_SECTION_MISMATCH
882KBUILD_CFLAGS += -fno-inline-functions-called-once
883endif
884
885ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
886KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
887LDFLAGS_vmlinux += --gc-sections
888endif
889
890ifdef CONFIG_SHADOW_CALL_STACK
891CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
892KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
893export CC_FLAGS_SCS
894endif
895
896ifdef CONFIG_LTO_CLANG
897ifdef CONFIG_LTO_CLANG_THIN
898CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
899KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
900else
901CC_FLAGS_LTO	:= -flto
902endif
903CC_FLAGS_LTO	+= -fvisibility=hidden
904
905# Limit inlining across translation units to reduce binary size
906KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
907
908# Check for frame size exceeding threshold during prolog/epilog insertion
909# when using lld < 13.0.0.
910ifneq ($(CONFIG_FRAME_WARN),0)
911ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
912KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
913endif
914endif
915endif
916
917ifdef CONFIG_LTO
918KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
919KBUILD_AFLAGS	+= -fno-lto
920export CC_FLAGS_LTO
921endif
922
923ifdef CONFIG_CFI_CLANG
924CC_FLAGS_CFI	:= -fsanitize=cfi \
925		   -fsanitize-cfi-cross-dso \
926		   -fno-sanitize-cfi-canonical-jump-tables \
927		   -fno-sanitize-trap=cfi \
928		   -fno-sanitize-blacklist
929
930ifdef CONFIG_CFI_PERMISSIVE
931CC_FLAGS_CFI	+= -fsanitize-recover=cfi
932endif
933
934# If LTO flags are filtered out, we must also filter out CFI.
935CC_FLAGS_LTO	+= $(CC_FLAGS_CFI)
936KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
937export CC_FLAGS_CFI
938endif
939
940ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
941KBUILD_CFLAGS += -falign-functions=64
942endif
943
944# arch Makefile may override CC so keep this after arch Makefile is included
945NOSTDINC_FLAGS += -nostdinc
946
947# warn about C99 declaration after statement
948KBUILD_CFLAGS += -Wdeclaration-after-statement
949
950# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
951KBUILD_CFLAGS += -Wvla
952
953# disable pointer signed / unsigned warnings in gcc 4.0
954KBUILD_CFLAGS += -Wno-pointer-sign
955
956# disable stringop warnings in gcc 8+
957KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
958
959# We'll want to enable this eventually, but it's not going away for 5.7 at least
960KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
961KBUILD_CFLAGS += -Wno-array-bounds
962KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
963
964# Another good warning that we'll want to enable eventually
965KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
966
967# Enabled with W=2, disabled by default as noisy
968ifdef CONFIG_CC_IS_GCC
969KBUILD_CFLAGS += -Wno-maybe-uninitialized
970endif
971
972ifdef CONFIG_CC_IS_GCC
973# The allocators already balk at large sizes, so silence the compiler
974# warnings for bounds checks involving those possible values. While
975# -Wno-alloc-size-larger-than would normally be used here, earlier versions
976# of gcc (<9.1) weirdly don't handle the option correctly when _other_
977# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
978# doesn't work (as it is documented to), silently resolving to "0" prior to
979# version 9.1 (and producing an error more recently). Numeric values larger
980# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
981# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
982# choice, we must perform a versioned check to disable this warning.
983# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
984KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
985endif
986
987# disable invalid "can't wrap" optimizations for signed / pointers
988KBUILD_CFLAGS	+= -fno-strict-overflow
989
990# Make sure -fstack-check isn't enabled (like gentoo apparently did)
991KBUILD_CFLAGS  += -fno-stack-check
992
993# conserve stack if available
994ifdef CONFIG_CC_IS_GCC
995KBUILD_CFLAGS   += -fconserve-stack
996endif
997
998# Prohibit date/time macros, which would make the build non-deterministic
999KBUILD_CFLAGS   += -Werror=date-time
1000
1001# enforce correct pointer usage
1002KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1003
1004# Require designated initializers for all marked structures
1005KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1006
1007# change __FILE__ to the relative path from the srctree
1008KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1009
1010# include additional Makefiles when needed
1011include-y			:= scripts/Makefile.extrawarn
1012include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1013include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1014include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1015include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1016include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1017include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1018
1019include $(addprefix $(srctree)/, $(include-y))
1020
1021# scripts/Makefile.gcc-plugins is intentionally included last.
1022# Do not add $(call cc-option,...) below this line. When you build the kernel
1023# from the clean source tree, the GCC plugins do not exist at this point.
1024
1025# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1026KBUILD_CPPFLAGS += $(KCPPFLAGS)
1027KBUILD_AFLAGS   += $(KAFLAGS)
1028KBUILD_CFLAGS   += $(KCFLAGS)
1029
1030KBUILD_LDFLAGS_MODULE += --build-id=sha1
1031LDFLAGS_vmlinux += --build-id=sha1
1032
1033ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1034LDFLAGS_vmlinux	+= $(call ld-option, -X,)
1035endif
1036
1037ifeq ($(CONFIG_RELR),y)
1038LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1039endif
1040
1041# We never want expected sections to be placed heuristically by the
1042# linker. All sections should be explicitly named in the linker script.
1043ifdef CONFIG_LD_ORPHAN_WARN
1044LDFLAGS_vmlinux += --orphan-handling=warn
1045endif
1046
1047# Align the bit size of userspace programs with the kernel
1048KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1049KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1050
1051# make the checker run with the right architecture
1052CHECKFLAGS += --arch=$(ARCH)
1053
1054# insure the checker run with the right endianness
1055CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1056
1057# the checker needs the correct machine size
1058CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1059
1060# Default kernel image to build when no specific target is given.
1061# KBUILD_IMAGE may be overruled on the command line or
1062# set in the environment
1063# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1064# this default value
1065export KBUILD_IMAGE ?= vmlinux
1066
1067#
1068# INSTALL_PATH specifies where to place the updated kernel and system map
1069# images. Default is /boot, but you can set it to other values
1070export	INSTALL_PATH ?= /boot
1071
1072#
1073# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1074# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1075# an argument if needed. Otherwise it defaults to the kernel install path
1076#
1077export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1078
1079#
1080# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1081# relocations required by build roots.  This is not defined in the
1082# makefile but the argument can be passed to make if needed.
1083#
1084
1085MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1086export MODLIB
1087
1088PHONY += prepare0
1089
1090export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1091export MODORDER := $(extmod_prefix)modules.order
1092export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1093
1094ifeq ($(KBUILD_EXTMOD),)
1095core-y			+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
1096core-$(CONFIG_BLOCK)	+= block/
1097
1098vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1099		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1100		     $(libs-y) $(libs-m)))
1101
1102vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1103		     $(patsubst %/,%,$(filter %/, $(core-) \
1104			$(drivers-) $(libs-))))
1105
1106subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1107			$(core-y) $(core-m) $(libs-y) $(libs-m) \
1108			$(drivers-y) $(drivers-m)))
1109
1110build-dirs	:= $(vmlinux-dirs)
1111clean-dirs	:= $(vmlinux-alldirs)
1112
1113# Externally visible symbols (used by link-vmlinux.sh)
1114KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1115KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1116ifdef CONFIG_MODULES
1117KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1118KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1119else
1120KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1121endif
1122KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1123
1124export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1125export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1126# used by scripts/Makefile.package
1127export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1128
1129vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1130
1131# Recurse until adjust_autoksyms.sh is satisfied
1132PHONY += autoksyms_recursive
1133ifdef CONFIG_TRIM_UNUSED_KSYMS
1134# For the kernel to actually contain only the needed exported symbols,
1135# we have to build modules as well to determine what those symbols are.
1136# (this can be evaluated only once include/config/auto.conf has been included)
1137KBUILD_MODULES := 1
1138
1139autoksyms_recursive: descend modules.order
1140	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1141	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1142endif
1143
1144autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1145
1146quiet_cmd_autoksyms_h = GEN     $@
1147      cmd_autoksyms_h = mkdir -p $(dir $@); \
1148			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1149
1150$(autoksyms_h):
1151	$(call cmd,autoksyms_h)
1152
1153ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1154
1155# Final link of vmlinux with optional arch pass after final link
1156cmd_link-vmlinux =                                                 \
1157	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1158	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1159
1160vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1161	+$(call if_changed_dep,link-vmlinux)
1162
1163targets := vmlinux
1164
1165# The actual objects are generated when descending,
1166# make sure no implicit rule kicks in
1167$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1168
1169filechk_kernel.release = \
1170	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1171
1172# Store (new) KERNELRELEASE string in include/config/kernel.release
1173include/config/kernel.release: FORCE
1174	$(call filechk,kernel.release)
1175
1176# Additional helpers built in scripts/
1177# Carefully list dependencies so we do not try to build scripts twice
1178# in parallel
1179PHONY += scripts
1180scripts: scripts_basic scripts_dtc
1181	$(Q)$(MAKE) $(build)=$(@)
1182
1183# Things we need to do before we recursively start building the kernel
1184# or the modules are listed in "prepare".
1185# A multi level approach is used. prepareN is processed before prepareN-1.
1186# archprepare is used in arch Makefiles and when processed asm symlink,
1187# version.h and scripts_basic is processed / created.
1188
1189PHONY += prepare archprepare
1190
1191archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1192	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1193	include/generated/autoconf.h remove-stale-files
1194
1195prepare0: archprepare
1196	$(Q)$(MAKE) $(build)=scripts/mod
1197	$(Q)$(MAKE) $(build)=.
1198
1199# All the preparing..
1200prepare: prepare0
1201
1202PHONY += remove-stale-files
1203remove-stale-files:
1204	$(Q)$(srctree)/scripts/remove-stale-files
1205
1206# Support for using generic headers in asm-generic
1207asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1208
1209PHONY += asm-generic uapi-asm-generic
1210asm-generic: uapi-asm-generic
1211	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1212	generic=include/asm-generic
1213uapi-asm-generic:
1214	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1215	generic=include/uapi/asm-generic
1216
1217# Generate some files
1218# ---------------------------------------------------------------------------
1219
1220# KERNELRELEASE can change from a few different places, meaning version.h
1221# needs to be updated, so this check is forced on all builds
1222
1223uts_len := 64
1224define filechk_utsrelease.h
1225	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1226	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1227	  exit 1;                                                         \
1228	fi;                                                               \
1229	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1230endef
1231
1232define filechk_version.h
1233	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1234		echo \#define LINUX_VERSION_CODE $(shell                 \
1235		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1236	else                                                             \
1237		echo \#define LINUX_VERSION_CODE $(shell                 \
1238		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1239	fi;                                                              \
1240	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1241	((c) > 255 ? 255 : (c)))';                                       \
1242	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1243	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1244	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1245endef
1246
1247$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1248$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1249$(version_h): FORCE
1250	$(call filechk,version.h)
1251
1252include/generated/utsrelease.h: include/config/kernel.release FORCE
1253	$(call filechk,utsrelease.h)
1254
1255PHONY += headerdep
1256headerdep:
1257	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1258	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1259
1260# ---------------------------------------------------------------------------
1261# Kernel headers
1262
1263#Default location for installed headers
1264export INSTALL_HDR_PATH = $(objtree)/usr
1265
1266quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1267      cmd_headers_install = \
1268	mkdir -p $(INSTALL_HDR_PATH); \
1269	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1270	usr/include $(INSTALL_HDR_PATH)
1271
1272PHONY += headers_install
1273headers_install: headers
1274	$(call cmd,headers_install)
1275
1276PHONY += archheaders archscripts
1277
1278hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1279
1280PHONY += headers
1281headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1282	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1283	  $(error Headers not exportable for the $(SRCARCH) architecture))
1284	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1285	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1286
1287# Deprecated. It is no-op now.
1288PHONY += headers_check
1289headers_check:
1290	@echo >&2 "=================== WARNING ==================="
1291	@echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1292	@echo >&2 "and will be removed after Linux 5.15 release."
1293	@echo >&2 "Please remove headers_check from your scripts."
1294	@echo >&2 "==============================================="
1295
1296ifdef CONFIG_HEADERS_INSTALL
1297prepare: headers
1298endif
1299
1300PHONY += scripts_unifdef
1301scripts_unifdef: scripts_basic
1302	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1303
1304# ---------------------------------------------------------------------------
1305# Install
1306
1307# Many distributions have the custom install script, /sbin/installkernel.
1308# If DKMS is installed, 'make install' will eventually recuses back
1309# to the this Makefile to build and install external modules.
1310# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1311
1312install: sub_make_done :=
1313
1314# ---------------------------------------------------------------------------
1315# Tools
1316
1317ifdef CONFIG_STACK_VALIDATION
1318prepare: tools/objtool
1319endif
1320
1321ifdef CONFIG_BPF
1322ifdef CONFIG_DEBUG_INFO_BTF
1323prepare: tools/bpf/resolve_btfids
1324endif
1325endif
1326
1327PHONY += resolve_btfids_clean
1328
1329resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1330
1331# tools/bpf/resolve_btfids directory might not exist
1332# in output directory, skip its clean in that case
1333resolve_btfids_clean:
1334ifneq ($(wildcard $(resolve_btfids_O)),)
1335	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1336endif
1337
1338# Clear a bunch of variables before executing the submake
1339ifeq ($(quiet),silent_)
1340tools_silent=s
1341endif
1342
1343tools/: FORCE
1344	$(Q)mkdir -p $(objtree)/tools
1345	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1346
1347tools/%: FORCE
1348	$(Q)mkdir -p $(objtree)/tools
1349	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1350
1351# ---------------------------------------------------------------------------
1352# Kernel selftest
1353
1354PHONY += kselftest
1355kselftest:
1356	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1357
1358kselftest-%: FORCE
1359	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1360
1361PHONY += kselftest-merge
1362kselftest-merge:
1363	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1364	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1365		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1366	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1367
1368# ---------------------------------------------------------------------------
1369# Devicetree files
1370
1371ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1372dtstree := arch/$(SRCARCH)/boot/dts
1373endif
1374
1375ifneq ($(dtstree),)
1376
1377%.dtb: dt_binding_check include/config/kernel.release scripts_dtc
1378	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ $(dtstree)/$*.dt.yaml
1379
1380%.dtbo: dt_binding_check include/config/kernel.release scripts_dtc
1381	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@ $(dtstree)/$*.dt.yaml
1382
1383PHONY += dtbs dtbs_install dtbs_check
1384dtbs: include/config/kernel.release scripts_dtc
1385	$(Q)$(MAKE) $(build)=$(dtstree)
1386
1387ifneq ($(filter dtbs_check %.dtb %.dtbo, $(MAKECMDGOALS)),)
1388export CHECK_DTBS=y
1389dtbs: dt_binding_check
1390endif
1391
1392dtbs_check: dtbs
1393
1394dtbs_install:
1395	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1396
1397ifdef CONFIG_OF_EARLY_FLATTREE
1398all: dtbs
1399endif
1400
1401endif
1402
1403PHONY += scripts_dtc
1404scripts_dtc: scripts_basic
1405	$(Q)$(MAKE) $(build)=scripts/dtc
1406
1407ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1408export CHECK_DT_BINDING=y
1409endif
1410
1411PHONY += dt_binding_check
1412dt_binding_check: scripts_dtc
1413	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1414
1415# ---------------------------------------------------------------------------
1416# Modules
1417
1418ifdef CONFIG_MODULES
1419
1420# By default, build modules as well
1421
1422all: modules
1423
1424# When we're building modules with modversions, we need to consider
1425# the built-in objects during the descend as well, in order to
1426# make sure the checksums are up to date before we record them.
1427ifdef CONFIG_MODVERSIONS
1428  KBUILD_BUILTIN := 1
1429endif
1430
1431# Build modules
1432#
1433# A module can be listed more than once in obj-m resulting in
1434# duplicate lines in modules.order files.  Those are removed
1435# using awk while concatenating to the final file.
1436
1437PHONY += modules
1438modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1439
1440cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1441
1442modules.order: $(subdir-modorder) FORCE
1443	$(call if_changed,modules_order)
1444
1445targets += modules.order
1446
1447# Target to prepare building external modules
1448PHONY += modules_prepare
1449modules_prepare: prepare
1450	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1451
1452export modules_sign_only :=
1453
1454ifeq ($(CONFIG_MODULE_SIG),y)
1455PHONY += modules_sign
1456modules_sign: modules_install
1457	@:
1458
1459# modules_sign is a subset of modules_install.
1460# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1461ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1462modules_sign_only := y
1463endif
1464endif
1465
1466modinst_pre :=
1467ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1468modinst_pre := __modinst_pre
1469endif
1470
1471modules_install: $(modinst_pre)
1472PHONY += __modinst_pre
1473__modinst_pre:
1474	@rm -rf $(MODLIB)/kernel
1475	@rm -f $(MODLIB)/source
1476	@mkdir -p $(MODLIB)/kernel
1477	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1478	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1479		rm -f $(MODLIB)/build ; \
1480		ln -s $(CURDIR) $(MODLIB)/build ; \
1481	fi
1482	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1483	@cp -f modules.builtin $(MODLIB)/
1484	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1485
1486endif # CONFIG_MODULES
1487
1488###
1489# Cleaning is done on three levels.
1490# make clean     Delete most generated files
1491#                Leave enough to build external modules
1492# make mrproper  Delete the current configuration, and all generated files
1493# make distclean Remove editor backup files, patch leftover files and the like
1494
1495# Directories & files removed with 'make clean'
1496CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1497	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1498	       compile_commands.json .thinlto-cache
1499
1500# Directories & files removed with 'make mrproper'
1501MRPROPER_FILES += include/config include/generated          \
1502		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1503		  debian snap tar-install \
1504		  .config .config.old .version \
1505		  Module.symvers \
1506		  certs/signing_key.pem certs/signing_key.x509 \
1507		  certs/x509.genkey \
1508		  vmlinux-gdb.py \
1509		  *.spec
1510
1511# clean - Delete most, but leave enough to build external modules
1512#
1513clean: rm-files := $(CLEAN_FILES)
1514
1515PHONY += archclean vmlinuxclean
1516
1517vmlinuxclean:
1518	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1519	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1520
1521clean: archclean vmlinuxclean resolve_btfids_clean
1522
1523# mrproper - Delete all generated files, including .config
1524#
1525mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1526mrproper-dirs      := $(addprefix _mrproper_,scripts)
1527
1528PHONY += $(mrproper-dirs) mrproper
1529$(mrproper-dirs):
1530	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1531
1532mrproper: clean $(mrproper-dirs)
1533	$(call cmd,rmfiles)
1534
1535# distclean
1536#
1537PHONY += distclean
1538
1539distclean: mrproper
1540	@find . $(RCS_FIND_IGNORE) \
1541		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1542		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1543		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1544		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1545		-type f -print | xargs rm -f
1546
1547
1548# Packaging of the kernel to various formats
1549# ---------------------------------------------------------------------------
1550
1551%src-pkg: FORCE
1552	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1553%pkg: include/config/kernel.release FORCE
1554	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1555
1556# Brief documentation of the typical targets used
1557# ---------------------------------------------------------------------------
1558
1559boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1560boards := $(sort $(notdir $(boards)))
1561board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1562board-dirs := $(sort $(notdir $(board-dirs:/=)))
1563
1564PHONY += help
1565help:
1566	@echo  'Cleaning targets:'
1567	@echo  '  clean		  - Remove most generated files but keep the config and'
1568	@echo  '                    enough build support to build external modules'
1569	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1570	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1571	@echo  ''
1572	@echo  'Configuration targets:'
1573	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1574	@echo  ''
1575	@echo  'Other generic targets:'
1576	@echo  '  all		  - Build all targets marked with [*]'
1577	@echo  '* vmlinux	  - Build the bare kernel'
1578	@echo  '* modules	  - Build all modules'
1579	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1580	@echo  '  dir/            - Build all files in dir and below'
1581	@echo  '  dir/file.[ois]  - Build specified target only'
1582	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1583	@echo  '                    (requires compiler support for LLVM assembly generation)'
1584	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1585	@echo  '                    (requires a recent binutils and recent build (System.map))'
1586	@echo  '  dir/file.ko     - Build module including final link'
1587	@echo  '  modules_prepare - Set up for building external modules'
1588	@echo  '  tags/TAGS	  - Generate tags file for editors'
1589	@echo  '  cscope	  - Generate cscope index'
1590	@echo  '  gtags           - Generate GNU GLOBAL index'
1591	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1592	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1593	@echo  '  image_name	  - Output the image name (use with make -s)'
1594	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1595	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1596	 echo  ''
1597	@echo  'Static analysers:'
1598	@echo  '  checkstack      - Generate a list of stack hogs'
1599	@echo  '  versioncheck    - Sanity check on version.h usage'
1600	@echo  '  includecheck    - Check for duplicate included header files'
1601	@echo  '  export_report   - List the usages of all exported symbols'
1602	@echo  '  headerdep       - Detect inclusion cycles in headers'
1603	@echo  '  coccicheck      - Check with Coccinelle'
1604	@echo  '  clang-analyzer  - Check with clang static analyzer'
1605	@echo  '  clang-tidy      - Check with clang-tidy'
1606	@echo  ''
1607	@echo  'Tools:'
1608	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1609	@echo  ''
1610	@echo  'Kernel selftest:'
1611	@echo  '  kselftest         - Build and run kernel selftest'
1612	@echo  '                      Build, install, and boot kernel before'
1613	@echo  '                      running kselftest on it'
1614	@echo  '                      Run as root for full coverage'
1615	@echo  '  kselftest-all     - Build kernel selftest'
1616	@echo  '  kselftest-install - Build and install kernel selftest'
1617	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1618	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1619	@echo  '		      kselftest to existing .config.'
1620	@echo  ''
1621	@$(if $(dtstree), \
1622		echo 'Devicetree:'; \
1623		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1624		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1625		echo '  dt_binding_check - Validate device tree binding documents'; \
1626		echo '  dtbs_check       - Validate device tree source files';\
1627		echo '')
1628
1629	@echo 'Userspace tools targets:'
1630	@echo '  use "make tools/help"'
1631	@echo '  or  "cd tools; make help"'
1632	@echo  ''
1633	@echo  'Kernel packaging:'
1634	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1635	@echo  ''
1636	@echo  'Documentation targets:'
1637	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1638	@echo  ''
1639	@echo  'Architecture specific targets ($(SRCARCH)):'
1640	@$(if $(archhelp),$(archhelp),\
1641		echo '  No architecture specific help defined for $(SRCARCH)')
1642	@echo  ''
1643	@$(if $(boards), \
1644		$(foreach b, $(boards), \
1645		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1646		echo '')
1647	@$(if $(board-dirs), \
1648		$(foreach b, $(board-dirs), \
1649		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1650		printf "  %-16s - Show all of the above\\n" help-boards; \
1651		echo '')
1652
1653	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1654	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
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  '		Multiple levels can be combined with W=12 or W=123'
1665	@echo  ''
1666	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1667	@echo  'For further info see the ./README file'
1668
1669
1670help-board-dirs := $(addprefix help-,$(board-dirs))
1671
1672help-boards: $(help-board-dirs)
1673
1674boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1675
1676$(help-board-dirs): help-%:
1677	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1678	@$(if $(boards-per-dir), \
1679		$(foreach b, $(boards-per-dir), \
1680		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1681		echo '')
1682
1683
1684# Documentation targets
1685# ---------------------------------------------------------------------------
1686DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1687	       linkcheckdocs dochelp refcheckdocs
1688PHONY += $(DOC_TARGETS)
1689$(DOC_TARGETS):
1690	$(Q)$(MAKE) $(build)=Documentation $@
1691
1692# Misc
1693# ---------------------------------------------------------------------------
1694
1695PHONY += scripts_gdb
1696scripts_gdb: prepare0
1697	$(Q)$(MAKE) $(build)=scripts/gdb
1698	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1699
1700ifdef CONFIG_GDB_SCRIPTS
1701all: scripts_gdb
1702endif
1703
1704else # KBUILD_EXTMOD
1705
1706###
1707# External module support.
1708# When building external modules the kernel used as basis is considered
1709# read-only, and no consistency checks are made and the make
1710# system is not used on the basis kernel. If updates are required
1711# in the basis kernel ordinary make commands (without M=...) must be used.
1712
1713# We are always building only modules.
1714KBUILD_BUILTIN :=
1715KBUILD_MODULES := 1
1716
1717build-dirs := $(KBUILD_EXTMOD)
1718$(MODORDER): descend
1719	@:
1720
1721compile_commands.json: $(extmod_prefix)compile_commands.json
1722PHONY += compile_commands.json
1723
1724clean-dirs := $(KBUILD_EXTMOD)
1725clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1726	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1727
1728PHONY += prepare
1729# now expand this into a simple variable to reduce the cost of shell evaluations
1730prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1731prepare:
1732	@if [ "$(CC_VERSION_TEXT)" != $(CONFIG_CC_VERSION_TEXT) ]; then \
1733		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1734		echo >&2 "  The kernel was built by: "$(CONFIG_CC_VERSION_TEXT); \
1735		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1736	fi
1737
1738PHONY += help
1739help:
1740	@echo  '  Building external modules.'
1741	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1742	@echo  ''
1743	@echo  '  modules         - default target, build the module(s)'
1744	@echo  '  modules_install - install the module'
1745	@echo  '  clean           - remove generated files in module directory only'
1746	@echo  ''
1747
1748# no-op for external module builds
1749PHONY += modules_prepare
1750
1751endif # KBUILD_EXTMOD
1752
1753# ---------------------------------------------------------------------------
1754# Modules
1755
1756PHONY += modules modules_install
1757
1758ifdef CONFIG_MODULES
1759
1760modules: modules_check
1761	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1762
1763PHONY += modules_check
1764modules_check: $(MODORDER)
1765	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1766
1767quiet_cmd_depmod = DEPMOD  $(MODLIB)
1768      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1769                   $(KERNELRELEASE)
1770
1771modules_install:
1772	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1773	$(call cmd,depmod)
1774
1775else # CONFIG_MODULES
1776
1777# Modules not configured
1778# ---------------------------------------------------------------------------
1779
1780modules modules_install:
1781	@echo >&2 '***'
1782	@echo >&2 '*** The present kernel configuration has modules disabled.'
1783	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1784	@echo >&2 '*** to enable CONFIG_MODULES.'
1785	@echo >&2 '***'
1786	@exit 1
1787
1788endif # CONFIG_MODULES
1789
1790# Single targets
1791# ---------------------------------------------------------------------------
1792# To build individual files in subdirectories, you can do like this:
1793#
1794#   make foo/bar/baz.s
1795#
1796# The supported suffixes for single-target are listed in 'single-targets'
1797#
1798# To build only under specific subdirectories, you can do like this:
1799#
1800#   make foo/bar/baz/
1801
1802ifdef single-build
1803
1804# .ko is special because modpost is needed
1805single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1806single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1807
1808$(single-ko): single_modpost
1809	@:
1810$(single-no-ko): descend
1811	@:
1812
1813ifeq ($(KBUILD_EXTMOD),)
1814# For the single build of in-tree modules, use a temporary file to avoid
1815# the situation of modules_install installing an invalid modules.order.
1816MODORDER := .modules.tmp
1817endif
1818
1819PHONY += single_modpost
1820single_modpost: $(single-no-ko) modules_prepare
1821	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1822	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1823
1824KBUILD_MODULES := 1
1825
1826export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1827
1828# trim unrelated directories
1829build-dirs := $(foreach d, $(build-dirs), \
1830			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1831
1832endif
1833
1834ifndef CONFIG_MODULES
1835KBUILD_MODULES :=
1836endif
1837
1838# Handle descending into subdirectories listed in $(build-dirs)
1839# Preset locale variables to speed up the build process. Limit locale
1840# tweaks to this spot to avoid wrong language settings when running
1841# make menuconfig etc.
1842# Error messages still appears in the original language
1843PHONY += descend $(build-dirs)
1844descend: $(build-dirs)
1845$(build-dirs): prepare
1846	$(Q)$(MAKE) $(build)=$@ \
1847	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1848	need-builtin=1 need-modorder=1
1849
1850clean-dirs := $(addprefix _clean_, $(clean-dirs))
1851PHONY += $(clean-dirs) clean
1852$(clean-dirs):
1853	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1854
1855clean: $(clean-dirs)
1856	$(call cmd,rmfiles)
1857	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1858		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1859		-o -name '*.ko.*' \
1860		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1861		-o -name '*.dwo' -o -name '*.lst' \
1862		-o -name '*.su' -o -name '*.mod' \
1863		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1864		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1865		-o -name '*.asn1.[ch]' \
1866		-o -name '*.symtypes' -o -name 'modules.order' \
1867		-o -name '.tmp_*.o.*' \
1868		-o -name '*.c.[012]*.*' \
1869		-o -name '*.ll' \
1870		-o -name '*.gcno' \
1871		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
1872
1873# Generate tags for editors
1874# ---------------------------------------------------------------------------
1875quiet_cmd_tags = GEN     $@
1876      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1877
1878tags TAGS cscope gtags: FORCE
1879	$(call cmd,tags)
1880
1881# Script to generate missing namespace dependencies
1882# ---------------------------------------------------------------------------
1883
1884PHONY += nsdeps
1885nsdeps: export KBUILD_NSDEPS=1
1886nsdeps: modules
1887	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1888
1889# Clang Tooling
1890# ---------------------------------------------------------------------------
1891
1892quiet_cmd_gen_compile_commands = GEN     $@
1893      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1894
1895$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1896	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1897	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1898	$(call if_changed,gen_compile_commands)
1899
1900targets += $(extmod_prefix)compile_commands.json
1901
1902PHONY += clang-tidy clang-analyzer
1903
1904ifdef CONFIG_CC_IS_CLANG
1905quiet_cmd_clang_tools = CHECK   $<
1906      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1907
1908clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1909	$(call cmd,clang_tools)
1910else
1911clang-tidy clang-analyzer:
1912	@echo "$@ requires CC=clang" >&2
1913	@false
1914endif
1915
1916# Scripts to check various things for consistency
1917# ---------------------------------------------------------------------------
1918
1919PHONY += includecheck versioncheck coccicheck export_report
1920
1921includecheck:
1922	find $(srctree)/* $(RCS_FIND_IGNORE) \
1923		-name '*.[hcS]' -type f -print | sort \
1924		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1925
1926versioncheck:
1927	find $(srctree)/* $(RCS_FIND_IGNORE) \
1928		-name '*.[hcS]' -type f -print | sort \
1929		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1930
1931coccicheck:
1932	$(Q)$(BASH) $(srctree)/scripts/$@
1933
1934export_report:
1935	$(PERL) $(srctree)/scripts/export_report.pl
1936
1937PHONY += checkstack kernelrelease kernelversion image_name
1938
1939# UML needs a little special treatment here.  It wants to use the host
1940# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1941# else wants $(ARCH), including people doing cross-builds, which means
1942# that $(SUBARCH) doesn't work here.
1943ifeq ($(ARCH), um)
1944CHECKSTACK_ARCH := $(SUBARCH)
1945else
1946CHECKSTACK_ARCH := $(ARCH)
1947endif
1948checkstack:
1949	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1950	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1951
1952kernelrelease:
1953	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1954
1955kernelversion:
1956	@echo $(KERNELVERSION)
1957
1958image_name:
1959	@echo $(KBUILD_IMAGE)
1960
1961quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1962      cmd_rmfiles = rm -rf $(rm-files)
1963
1964# read saved command lines for existing targets
1965existing-targets := $(wildcard $(sort $(targets)))
1966
1967-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1968
1969endif # config-build
1970endif # mixed-build
1971endif # need-sub-make
1972
1973PHONY += FORCE
1974FORCE:
1975
1976# Declare the contents of the PHONY variable as phony.  We keep that
1977# information in a variable so we can use it in if_changed and friends.
1978.PHONY: $(PHONY)
1979