xref: /openbmc/linux/Makefile (revision 827beb77)
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)
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# Warn about unmarked fall-throughs in switch statement.
805# Disabled for clang while comment to attribute conversion happens and
806# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
807KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,)
808# gcc inanely warns about local variables called 'main'
809KBUILD_CFLAGS += -Wno-main
810endif
811
812# These warnings generated too much noise in a regular build.
813# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
814KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
815KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
816
817ifdef CONFIG_FRAME_POINTER
818KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
819else
820# Some targets (ARM with Thumb2, for example), can't be built with frame
821# pointers.  For those, we don't have FUNCTION_TRACER automatically
822# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
823# incompatible with -fomit-frame-pointer with current GCC, so we don't use
824# -fomit-frame-pointer with FUNCTION_TRACER.
825ifndef CONFIG_FUNCTION_TRACER
826KBUILD_CFLAGS	+= -fomit-frame-pointer
827endif
828endif
829
830# Initialize all stack variables with a 0xAA pattern.
831ifdef CONFIG_INIT_STACK_ALL_PATTERN
832KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
833endif
834
835# Initialize all stack variables with a zero value.
836ifdef CONFIG_INIT_STACK_ALL_ZERO
837KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
838ifdef CONFIG_CC_IS_CLANG
839# https://bugs.llvm.org/show_bug.cgi?id=45497
840KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
841endif
842endif
843
844# While VLAs have been removed, GCC produces unreachable stack probes
845# for the randomize_kstack_offset feature. Disable it for all compilers.
846KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
847
848# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
849ifdef CONFIG_ZERO_CALL_USED_REGS
850KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
851endif
852
853DEBUG_CFLAGS	:=
854
855ifdef CONFIG_DEBUG_INFO
856
857ifdef CONFIG_DEBUG_INFO_SPLIT
858DEBUG_CFLAGS	+= -gsplit-dwarf
859else
860DEBUG_CFLAGS	+= -g
861endif
862
863ifndef CONFIG_AS_IS_LLVM
864KBUILD_AFLAGS	+= -Wa,-gdwarf-2
865endif
866
867ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
868dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
869dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
870DEBUG_CFLAGS	+= -gdwarf-$(dwarf-version-y)
871endif
872
873ifdef CONFIG_DEBUG_INFO_REDUCED
874DEBUG_CFLAGS	+= -fno-var-tracking
875ifdef CONFIG_CC_IS_GCC
876DEBUG_CFLAGS	+= -femit-struct-debug-baseonly
877endif
878endif
879
880ifdef CONFIG_DEBUG_INFO_COMPRESSED
881DEBUG_CFLAGS	+= -gz=zlib
882KBUILD_AFLAGS	+= -gz=zlib
883KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
884endif
885
886endif # CONFIG_DEBUG_INFO
887
888KBUILD_CFLAGS += $(DEBUG_CFLAGS)
889export DEBUG_CFLAGS
890
891ifdef CONFIG_FUNCTION_TRACER
892ifdef CONFIG_FTRACE_MCOUNT_USE_CC
893  CC_FLAGS_FTRACE	+= -mrecord-mcount
894  ifdef CONFIG_HAVE_NOP_MCOUNT
895    ifeq ($(call cc-option-yn, -mnop-mcount),y)
896      CC_FLAGS_FTRACE	+= -mnop-mcount
897      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
898    endif
899  endif
900endif
901ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
902  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
903endif
904ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
905  ifdef CONFIG_HAVE_C_RECORDMCOUNT
906    BUILD_C_RECORDMCOUNT := y
907    export BUILD_C_RECORDMCOUNT
908  endif
909endif
910ifdef CONFIG_HAVE_FENTRY
911  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
912  ifeq ($(call cc-option-yn, -mfentry),y)
913    CC_FLAGS_FTRACE	+= -mfentry
914    CC_FLAGS_USING	+= -DCC_USING_FENTRY
915  endif
916endif
917export CC_FLAGS_FTRACE
918KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
919KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
920endif
921
922# We trigger additional mismatches with less inlining
923ifdef CONFIG_DEBUG_SECTION_MISMATCH
924KBUILD_CFLAGS += -fno-inline-functions-called-once
925endif
926
927ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
928KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
929LDFLAGS_vmlinux += --gc-sections
930endif
931
932ifdef CONFIG_SHADOW_CALL_STACK
933CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
934KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
935export CC_FLAGS_SCS
936endif
937
938ifdef CONFIG_LTO_CLANG
939ifdef CONFIG_LTO_CLANG_THIN
940CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
941KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
942else
943CC_FLAGS_LTO	:= -flto
944endif
945CC_FLAGS_LTO	+= -fvisibility=hidden
946
947# Limit inlining across translation units to reduce binary size
948KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
949
950# Check for frame size exceeding threshold during prolog/epilog insertion
951# when using lld < 13.0.0.
952ifneq ($(CONFIG_FRAME_WARN),0)
953ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
954KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
955endif
956endif
957endif
958
959ifdef CONFIG_LTO
960KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
961KBUILD_AFLAGS	+= -fno-lto
962export CC_FLAGS_LTO
963endif
964
965ifdef CONFIG_CFI_CLANG
966CC_FLAGS_CFI	:= -fsanitize=cfi \
967		   -fsanitize-cfi-cross-dso \
968		   -fno-sanitize-cfi-canonical-jump-tables \
969		   -fno-sanitize-trap=cfi \
970		   -fno-sanitize-blacklist
971
972ifdef CONFIG_CFI_PERMISSIVE
973CC_FLAGS_CFI	+= -fsanitize-recover=cfi
974endif
975
976# If LTO flags are filtered out, we must also filter out CFI.
977CC_FLAGS_LTO	+= $(CC_FLAGS_CFI)
978KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
979export CC_FLAGS_CFI
980endif
981
982ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
983KBUILD_CFLAGS += -falign-functions=64
984endif
985
986# arch Makefile may override CC so keep this after arch Makefile is included
987NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
988
989# warn about C99 declaration after statement
990KBUILD_CFLAGS += -Wdeclaration-after-statement
991
992# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
993KBUILD_CFLAGS += -Wvla
994
995# disable pointer signed / unsigned warnings in gcc 4.0
996KBUILD_CFLAGS += -Wno-pointer-sign
997
998# disable stringop warnings in gcc 8+
999KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1000
1001# We'll want to enable this eventually, but it's not going away for 5.7 at least
1002KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
1003KBUILD_CFLAGS += -Wno-array-bounds
1004KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1005
1006# Another good warning that we'll want to enable eventually
1007KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1008
1009# Enabled with W=2, disabled by default as noisy
1010ifdef CONFIG_CC_IS_GCC
1011KBUILD_CFLAGS += -Wno-maybe-uninitialized
1012endif
1013
1014# disable invalid "can't wrap" optimizations for signed / pointers
1015KBUILD_CFLAGS	+= -fno-strict-overflow
1016
1017# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1018KBUILD_CFLAGS  += -fno-stack-check
1019
1020# conserve stack if available
1021ifdef CONFIG_CC_IS_GCC
1022KBUILD_CFLAGS   += -fconserve-stack
1023endif
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/
1122core-$(CONFIG_BLOCK)	+= block/
1123
1124vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1125		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1126		     $(libs-y) $(libs-m)))
1127
1128vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1129		     $(patsubst %/,%,$(filter %/, $(core-) \
1130			$(drivers-) $(libs-))))
1131
1132subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1133			$(core-y) $(core-m) $(libs-y) $(libs-m) \
1134			$(drivers-y) $(drivers-m)))
1135
1136build-dirs	:= $(vmlinux-dirs)
1137clean-dirs	:= $(vmlinux-alldirs)
1138
1139# Externally visible symbols (used by link-vmlinux.sh)
1140KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1141KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1142ifdef CONFIG_MODULES
1143KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1144KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1145else
1146KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1147endif
1148KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1149
1150export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1151export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1152# used by scripts/Makefile.package
1153export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1154
1155vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1156
1157# Recurse until adjust_autoksyms.sh is satisfied
1158PHONY += autoksyms_recursive
1159ifdef CONFIG_TRIM_UNUSED_KSYMS
1160# For the kernel to actually contain only the needed exported symbols,
1161# we have to build modules as well to determine what those symbols are.
1162# (this can be evaluated only once include/config/auto.conf has been included)
1163KBUILD_MODULES := 1
1164
1165autoksyms_recursive: descend modules.order
1166	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1167	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1168endif
1169
1170autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1171
1172quiet_cmd_autoksyms_h = GEN     $@
1173      cmd_autoksyms_h = mkdir -p $(dir $@); \
1174			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1175
1176$(autoksyms_h):
1177	$(call cmd,autoksyms_h)
1178
1179ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1180
1181# Final link of vmlinux with optional arch pass after final link
1182cmd_link-vmlinux =                                                 \
1183	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1184	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1185
1186vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1187	+$(call if_changed_dep,link-vmlinux)
1188
1189targets := vmlinux
1190
1191# The actual objects are generated when descending,
1192# make sure no implicit rule kicks in
1193$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1194
1195filechk_kernel.release = \
1196	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1197
1198# Store (new) KERNELRELEASE string in include/config/kernel.release
1199include/config/kernel.release: FORCE
1200	$(call filechk,kernel.release)
1201
1202# Additional helpers built in scripts/
1203# Carefully list dependencies so we do not try to build scripts twice
1204# in parallel
1205PHONY += scripts
1206scripts: scripts_basic scripts_dtc
1207	$(Q)$(MAKE) $(build)=$(@)
1208
1209# Things we need to do before we recursively start building the kernel
1210# or the modules are listed in "prepare".
1211# A multi level approach is used. prepareN is processed before prepareN-1.
1212# archprepare is used in arch Makefiles and when processed asm symlink,
1213# version.h and scripts_basic is processed / created.
1214
1215PHONY += prepare archprepare
1216
1217archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1218	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1219	include/generated/autoconf.h remove-stale-files
1220
1221prepare0: archprepare
1222	$(Q)$(MAKE) $(build)=scripts/mod
1223	$(Q)$(MAKE) $(build)=.
1224
1225# All the preparing..
1226prepare: prepare0
1227
1228PHONY += remove-stale-files
1229remove-stale-files:
1230	$(Q)$(srctree)/scripts/remove-stale-files
1231
1232# Support for using generic headers in asm-generic
1233asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1234
1235PHONY += asm-generic uapi-asm-generic
1236asm-generic: uapi-asm-generic
1237	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1238	generic=include/asm-generic
1239uapi-asm-generic:
1240	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1241	generic=include/uapi/asm-generic
1242
1243# Generate some files
1244# ---------------------------------------------------------------------------
1245
1246# KERNELRELEASE can change from a few different places, meaning version.h
1247# needs to be updated, so this check is forced on all builds
1248
1249uts_len := 64
1250define filechk_utsrelease.h
1251	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1252	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1253	  exit 1;                                                         \
1254	fi;                                                               \
1255	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1256endef
1257
1258define filechk_version.h
1259	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1260		echo \#define LINUX_VERSION_CODE $(shell                 \
1261		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1262	else                                                             \
1263		echo \#define LINUX_VERSION_CODE $(shell                 \
1264		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1265	fi;                                                              \
1266	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1267	((c) > 255 ? 255 : (c)))';                                       \
1268	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1269	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1270	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1271endef
1272
1273$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1274$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1275$(version_h): FORCE
1276	$(call filechk,version.h)
1277
1278include/generated/utsrelease.h: include/config/kernel.release FORCE
1279	$(call filechk,utsrelease.h)
1280
1281PHONY += headerdep
1282headerdep:
1283	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1284	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1285
1286# ---------------------------------------------------------------------------
1287# Kernel headers
1288
1289#Default location for installed headers
1290export INSTALL_HDR_PATH = $(objtree)/usr
1291
1292quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1293      cmd_headers_install = \
1294	mkdir -p $(INSTALL_HDR_PATH); \
1295	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1296	usr/include $(INSTALL_HDR_PATH)
1297
1298PHONY += headers_install
1299headers_install: headers
1300	$(call cmd,headers_install)
1301
1302PHONY += archheaders archscripts
1303
1304hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1305
1306PHONY += headers
1307headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1308	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1309	  $(error Headers not exportable for the $(SRCARCH) architecture))
1310	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1311	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1312
1313# Deprecated. It is no-op now.
1314PHONY += headers_check
1315headers_check:
1316	@echo >&2 "=================== WARNING ==================="
1317	@echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1318	@echo >&2 "and will be removed after Linux 5.15 release."
1319	@echo >&2 "Please remove headers_check from your scripts."
1320	@echo >&2 "==============================================="
1321
1322ifdef CONFIG_HEADERS_INSTALL
1323prepare: headers
1324endif
1325
1326PHONY += scripts_unifdef
1327scripts_unifdef: scripts_basic
1328	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1329
1330# ---------------------------------------------------------------------------
1331# Install
1332
1333# Many distributions have the custom install script, /sbin/installkernel.
1334# If DKMS is installed, 'make install' will eventually recuses back
1335# to the this Makefile to build and install external modules.
1336# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1337
1338install: sub_make_done :=
1339
1340# ---------------------------------------------------------------------------
1341# Tools
1342
1343ifdef CONFIG_STACK_VALIDATION
1344prepare: tools/objtool
1345endif
1346
1347ifdef CONFIG_BPF
1348ifdef CONFIG_DEBUG_INFO_BTF
1349prepare: tools/bpf/resolve_btfids
1350endif
1351endif
1352
1353PHONY += resolve_btfids_clean
1354
1355resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1356
1357# tools/bpf/resolve_btfids directory might not exist
1358# in output directory, skip its clean in that case
1359resolve_btfids_clean:
1360ifneq ($(wildcard $(resolve_btfids_O)),)
1361	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1362endif
1363
1364# Clear a bunch of variables before executing the submake
1365ifeq ($(quiet),silent_)
1366tools_silent=s
1367endif
1368
1369tools/: FORCE
1370	$(Q)mkdir -p $(objtree)/tools
1371	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1372
1373tools/%: FORCE
1374	$(Q)mkdir -p $(objtree)/tools
1375	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1376
1377# ---------------------------------------------------------------------------
1378# Kernel selftest
1379
1380PHONY += kselftest
1381kselftest:
1382	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1383
1384kselftest-%: FORCE
1385	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1386
1387PHONY += kselftest-merge
1388kselftest-merge:
1389	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1390	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1391		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1392	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1393
1394# ---------------------------------------------------------------------------
1395# Devicetree files
1396
1397ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1398dtstree := arch/$(SRCARCH)/boot/dts
1399endif
1400
1401ifneq ($(dtstree),)
1402
1403%.dtb: include/config/kernel.release scripts_dtc
1404	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1405
1406%.dtbo: include/config/kernel.release scripts_dtc
1407	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1408
1409PHONY += dtbs dtbs_install dtbs_check
1410dtbs: include/config/kernel.release scripts_dtc
1411	$(Q)$(MAKE) $(build)=$(dtstree)
1412
1413ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1414export CHECK_DTBS=y
1415dtbs: dt_binding_check
1416endif
1417
1418dtbs_check: dtbs
1419
1420dtbs_install:
1421	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1422
1423ifdef CONFIG_OF_EARLY_FLATTREE
1424all: dtbs
1425endif
1426
1427endif
1428
1429PHONY += scripts_dtc
1430scripts_dtc: scripts_basic
1431	$(Q)$(MAKE) $(build)=scripts/dtc
1432
1433ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1434export CHECK_DT_BINDING=y
1435endif
1436
1437PHONY += dt_binding_check
1438dt_binding_check: scripts_dtc
1439	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1440
1441# ---------------------------------------------------------------------------
1442# Modules
1443
1444ifdef CONFIG_MODULES
1445
1446# By default, build modules as well
1447
1448all: modules
1449
1450# When we're building modules with modversions, we need to consider
1451# the built-in objects during the descend as well, in order to
1452# make sure the checksums are up to date before we record them.
1453ifdef CONFIG_MODVERSIONS
1454  KBUILD_BUILTIN := 1
1455endif
1456
1457# Build modules
1458#
1459# A module can be listed more than once in obj-m resulting in
1460# duplicate lines in modules.order files.  Those are removed
1461# using awk while concatenating to the final file.
1462
1463PHONY += modules
1464modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1465
1466cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1467
1468modules.order: $(subdir-modorder) FORCE
1469	$(call if_changed,modules_order)
1470
1471targets += modules.order
1472
1473# Target to prepare building external modules
1474PHONY += modules_prepare
1475modules_prepare: prepare
1476	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1477
1478export modules_sign_only :=
1479
1480ifeq ($(CONFIG_MODULE_SIG),y)
1481PHONY += modules_sign
1482modules_sign: modules_install
1483	@:
1484
1485# modules_sign is a subset of modules_install.
1486# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1487ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1488modules_sign_only := y
1489endif
1490endif
1491
1492modinst_pre :=
1493ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1494modinst_pre := __modinst_pre
1495endif
1496
1497modules_install: $(modinst_pre)
1498PHONY += __modinst_pre
1499__modinst_pre:
1500	@rm -rf $(MODLIB)/kernel
1501	@rm -f $(MODLIB)/source
1502	@mkdir -p $(MODLIB)/kernel
1503	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1504	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1505		rm -f $(MODLIB)/build ; \
1506		ln -s $(CURDIR) $(MODLIB)/build ; \
1507	fi
1508	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1509	@cp -f modules.builtin $(MODLIB)/
1510	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1511
1512endif # CONFIG_MODULES
1513
1514###
1515# Cleaning is done on three levels.
1516# make clean     Delete most generated files
1517#                Leave enough to build external modules
1518# make mrproper  Delete the current configuration, and all generated files
1519# make distclean Remove editor backup files, patch leftover files and the like
1520
1521# Directories & files removed with 'make clean'
1522CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1523	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1524	       compile_commands.json .thinlto-cache
1525
1526# Directories & files removed with 'make mrproper'
1527MRPROPER_FILES += include/config include/generated          \
1528		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1529		  debian snap tar-install \
1530		  .config .config.old .version \
1531		  Module.symvers \
1532		  certs/signing_key.pem certs/signing_key.x509 \
1533		  certs/x509.genkey \
1534		  vmlinux-gdb.py \
1535		  *.spec
1536
1537# clean - Delete most, but leave enough to build external modules
1538#
1539clean: rm-files := $(CLEAN_FILES)
1540
1541PHONY += archclean vmlinuxclean
1542
1543vmlinuxclean:
1544	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1545	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1546
1547clean: archclean vmlinuxclean resolve_btfids_clean
1548
1549# mrproper - Delete all generated files, including .config
1550#
1551mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1552mrproper-dirs      := $(addprefix _mrproper_,scripts)
1553
1554PHONY += $(mrproper-dirs) mrproper
1555$(mrproper-dirs):
1556	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1557
1558mrproper: clean $(mrproper-dirs)
1559	$(call cmd,rmfiles)
1560
1561# distclean
1562#
1563PHONY += distclean
1564
1565distclean: mrproper
1566	@find . $(RCS_FIND_IGNORE) \
1567		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1568		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1569		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1570		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1571		-type f -print | xargs rm -f
1572
1573
1574# Packaging of the kernel to various formats
1575# ---------------------------------------------------------------------------
1576
1577%src-pkg: FORCE
1578	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1579%pkg: include/config/kernel.release FORCE
1580	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1581
1582# Brief documentation of the typical targets used
1583# ---------------------------------------------------------------------------
1584
1585boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1586boards := $(sort $(notdir $(boards)))
1587board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1588board-dirs := $(sort $(notdir $(board-dirs:/=)))
1589
1590PHONY += help
1591help:
1592	@echo  'Cleaning targets:'
1593	@echo  '  clean		  - Remove most generated files but keep the config and'
1594	@echo  '                    enough build support to build external modules'
1595	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1596	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1597	@echo  ''
1598	@echo  'Configuration targets:'
1599	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1600	@echo  ''
1601	@echo  'Other generic targets:'
1602	@echo  '  all		  - Build all targets marked with [*]'
1603	@echo  '* vmlinux	  - Build the bare kernel'
1604	@echo  '* modules	  - Build all modules'
1605	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1606	@echo  '  dir/            - Build all files in dir and below'
1607	@echo  '  dir/file.[ois]  - Build specified target only'
1608	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1609	@echo  '                    (requires compiler support for LLVM assembly generation)'
1610	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1611	@echo  '                    (requires a recent binutils and recent build (System.map))'
1612	@echo  '  dir/file.ko     - Build module including final link'
1613	@echo  '  modules_prepare - Set up for building external modules'
1614	@echo  '  tags/TAGS	  - Generate tags file for editors'
1615	@echo  '  cscope	  - Generate cscope index'
1616	@echo  '  gtags           - Generate GNU GLOBAL index'
1617	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1618	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1619	@echo  '  image_name	  - Output the image name (use with make -s)'
1620	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1621	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1622	 echo  ''
1623	@echo  'Static analysers:'
1624	@echo  '  checkstack      - Generate a list of stack hogs'
1625	@echo  '  versioncheck    - Sanity check on version.h usage'
1626	@echo  '  includecheck    - Check for duplicate included header files'
1627	@echo  '  export_report   - List the usages of all exported symbols'
1628	@echo  '  headerdep       - Detect inclusion cycles in headers'
1629	@echo  '  coccicheck      - Check with Coccinelle'
1630	@echo  '  clang-analyzer  - Check with clang static analyzer'
1631	@echo  '  clang-tidy      - Check with clang-tidy'
1632	@echo  ''
1633	@echo  'Tools:'
1634	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1635	@echo  ''
1636	@echo  'Kernel selftest:'
1637	@echo  '  kselftest         - Build and run kernel selftest'
1638	@echo  '                      Build, install, and boot kernel before'
1639	@echo  '                      running kselftest on it'
1640	@echo  '                      Run as root for full coverage'
1641	@echo  '  kselftest-all     - Build kernel selftest'
1642	@echo  '  kselftest-install - Build and install kernel selftest'
1643	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1644	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1645	@echo  '		      kselftest to existing .config.'
1646	@echo  ''
1647	@$(if $(dtstree), \
1648		echo 'Devicetree:'; \
1649		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1650		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1651		echo '  dt_binding_check - Validate device tree binding documents'; \
1652		echo '  dtbs_check       - Validate device tree source files';\
1653		echo '')
1654
1655	@echo 'Userspace tools targets:'
1656	@echo '  use "make tools/help"'
1657	@echo '  or  "cd tools; make help"'
1658	@echo  ''
1659	@echo  'Kernel packaging:'
1660	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1661	@echo  ''
1662	@echo  'Documentation targets:'
1663	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1664	@echo  ''
1665	@echo  'Architecture specific targets ($(SRCARCH)):'
1666	@$(if $(archhelp),$(archhelp),\
1667		echo '  No architecture specific help defined for $(SRCARCH)')
1668	@echo  ''
1669	@$(if $(boards), \
1670		$(foreach b, $(boards), \
1671		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1672		echo '')
1673	@$(if $(board-dirs), \
1674		$(foreach b, $(board-dirs), \
1675		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1676		printf "  %-16s - Show all of the above\\n" help-boards; \
1677		echo '')
1678
1679	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1680	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1681	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1682	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1683	@echo  '                       (sparse by default)'
1684	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1685	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1686	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1687	@echo  '		1: warnings which may be relevant and do not occur too often'
1688	@echo  '		2: warnings which occur quite often but may still be relevant'
1689	@echo  '		3: more obscure warnings, can most likely be ignored'
1690	@echo  '		Multiple levels can be combined with W=12 or W=123'
1691	@echo  ''
1692	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1693	@echo  'For further info see the ./README file'
1694
1695
1696help-board-dirs := $(addprefix help-,$(board-dirs))
1697
1698help-boards: $(help-board-dirs)
1699
1700boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1701
1702$(help-board-dirs): help-%:
1703	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1704	@$(if $(boards-per-dir), \
1705		$(foreach b, $(boards-per-dir), \
1706		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1707		echo '')
1708
1709
1710# Documentation targets
1711# ---------------------------------------------------------------------------
1712DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1713	       linkcheckdocs dochelp refcheckdocs
1714PHONY += $(DOC_TARGETS)
1715$(DOC_TARGETS):
1716	$(Q)$(MAKE) $(build)=Documentation $@
1717
1718# Misc
1719# ---------------------------------------------------------------------------
1720
1721PHONY += scripts_gdb
1722scripts_gdb: prepare0
1723	$(Q)$(MAKE) $(build)=scripts/gdb
1724	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1725
1726ifdef CONFIG_GDB_SCRIPTS
1727all: scripts_gdb
1728endif
1729
1730else # KBUILD_EXTMOD
1731
1732###
1733# External module support.
1734# When building external modules the kernel used as basis is considered
1735# read-only, and no consistency checks are made and the make
1736# system is not used on the basis kernel. If updates are required
1737# in the basis kernel ordinary make commands (without M=...) must be used.
1738
1739# We are always building only modules.
1740KBUILD_BUILTIN :=
1741KBUILD_MODULES := 1
1742
1743build-dirs := $(KBUILD_EXTMOD)
1744$(MODORDER): descend
1745	@:
1746
1747compile_commands.json: $(extmod_prefix)compile_commands.json
1748PHONY += compile_commands.json
1749
1750clean-dirs := $(KBUILD_EXTMOD)
1751clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1752	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1753
1754PHONY += prepare
1755# now expand this into a simple variable to reduce the cost of shell evaluations
1756prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1757prepare:
1758	@if [ "$(CC_VERSION_TEXT)" != $(CONFIG_CC_VERSION_TEXT) ]; then \
1759		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1760		echo >&2 "  The kernel was built by: "$(CONFIG_CC_VERSION_TEXT); \
1761		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1762	fi
1763
1764PHONY += help
1765help:
1766	@echo  '  Building external modules.'
1767	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1768	@echo  ''
1769	@echo  '  modules         - default target, build the module(s)'
1770	@echo  '  modules_install - install the module'
1771	@echo  '  clean           - remove generated files in module directory only'
1772	@echo  ''
1773
1774# no-op for external module builds
1775PHONY += modules_prepare
1776
1777endif # KBUILD_EXTMOD
1778
1779# ---------------------------------------------------------------------------
1780# Modules
1781
1782PHONY += modules modules_install
1783
1784ifdef CONFIG_MODULES
1785
1786modules: modules_check
1787	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1788
1789PHONY += modules_check
1790modules_check: $(MODORDER)
1791	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1792
1793quiet_cmd_depmod = DEPMOD  $(MODLIB)
1794      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1795                   $(KERNELRELEASE)
1796
1797modules_install:
1798	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1799	$(call cmd,depmod)
1800
1801else # CONFIG_MODULES
1802
1803# Modules not configured
1804# ---------------------------------------------------------------------------
1805
1806modules modules_install:
1807	@echo >&2 '***'
1808	@echo >&2 '*** The present kernel configuration has modules disabled.'
1809	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1810	@echo >&2 '*** to enable CONFIG_MODULES.'
1811	@echo >&2 '***'
1812	@exit 1
1813
1814endif # CONFIG_MODULES
1815
1816# Single targets
1817# ---------------------------------------------------------------------------
1818# To build individual files in subdirectories, you can do like this:
1819#
1820#   make foo/bar/baz.s
1821#
1822# The supported suffixes for single-target are listed in 'single-targets'
1823#
1824# To build only under specific subdirectories, you can do like this:
1825#
1826#   make foo/bar/baz/
1827
1828ifdef single-build
1829
1830# .ko is special because modpost is needed
1831single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1832single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1833
1834$(single-ko): single_modpost
1835	@:
1836$(single-no-ko): descend
1837	@:
1838
1839ifeq ($(KBUILD_EXTMOD),)
1840# For the single build of in-tree modules, use a temporary file to avoid
1841# the situation of modules_install installing an invalid modules.order.
1842MODORDER := .modules.tmp
1843endif
1844
1845PHONY += single_modpost
1846single_modpost: $(single-no-ko) modules_prepare
1847	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1848	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1849
1850KBUILD_MODULES := 1
1851
1852export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1853
1854# trim unrelated directories
1855build-dirs := $(foreach d, $(build-dirs), \
1856			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1857
1858endif
1859
1860ifndef CONFIG_MODULES
1861KBUILD_MODULES :=
1862endif
1863
1864# Handle descending into subdirectories listed in $(build-dirs)
1865# Preset locale variables to speed up the build process. Limit locale
1866# tweaks to this spot to avoid wrong language settings when running
1867# make menuconfig etc.
1868# Error messages still appears in the original language
1869PHONY += descend $(build-dirs)
1870descend: $(build-dirs)
1871$(build-dirs): prepare
1872	$(Q)$(MAKE) $(build)=$@ \
1873	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1874	need-builtin=1 need-modorder=1
1875
1876clean-dirs := $(addprefix _clean_, $(clean-dirs))
1877PHONY += $(clean-dirs) clean
1878$(clean-dirs):
1879	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1880
1881clean: $(clean-dirs)
1882	$(call cmd,rmfiles)
1883	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1884		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1885		-o -name '*.ko.*' \
1886		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1887		-o -name '*.dwo' -o -name '*.lst' \
1888		-o -name '*.su' -o -name '*.mod' \
1889		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1890		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1891		-o -name '*.asn1.[ch]' \
1892		-o -name '*.symtypes' -o -name 'modules.order' \
1893		-o -name '.tmp_*.o.*' \
1894		-o -name '*.c.[012]*.*' \
1895		-o -name '*.ll' \
1896		-o -name '*.gcno' \
1897		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
1898
1899# Generate tags for editors
1900# ---------------------------------------------------------------------------
1901quiet_cmd_tags = GEN     $@
1902      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1903
1904tags TAGS cscope gtags: FORCE
1905	$(call cmd,tags)
1906
1907# Script to generate missing namespace dependencies
1908# ---------------------------------------------------------------------------
1909
1910PHONY += nsdeps
1911nsdeps: export KBUILD_NSDEPS=1
1912nsdeps: modules
1913	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1914
1915# Clang Tooling
1916# ---------------------------------------------------------------------------
1917
1918quiet_cmd_gen_compile_commands = GEN     $@
1919      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1920
1921$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1922	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1923	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1924	$(call if_changed,gen_compile_commands)
1925
1926targets += $(extmod_prefix)compile_commands.json
1927
1928PHONY += clang-tidy clang-analyzer
1929
1930ifdef CONFIG_CC_IS_CLANG
1931quiet_cmd_clang_tools = CHECK   $<
1932      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1933
1934clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1935	$(call cmd,clang_tools)
1936else
1937clang-tidy clang-analyzer:
1938	@echo "$@ requires CC=clang" >&2
1939	@false
1940endif
1941
1942# Scripts to check various things for consistency
1943# ---------------------------------------------------------------------------
1944
1945PHONY += includecheck versioncheck coccicheck export_report
1946
1947includecheck:
1948	find $(srctree)/* $(RCS_FIND_IGNORE) \
1949		-name '*.[hcS]' -type f -print | sort \
1950		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1951
1952versioncheck:
1953	find $(srctree)/* $(RCS_FIND_IGNORE) \
1954		-name '*.[hcS]' -type f -print | sort \
1955		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1956
1957coccicheck:
1958	$(Q)$(BASH) $(srctree)/scripts/$@
1959
1960export_report:
1961	$(PERL) $(srctree)/scripts/export_report.pl
1962
1963PHONY += checkstack kernelrelease kernelversion image_name
1964
1965# UML needs a little special treatment here.  It wants to use the host
1966# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1967# else wants $(ARCH), including people doing cross-builds, which means
1968# that $(SUBARCH) doesn't work here.
1969ifeq ($(ARCH), um)
1970CHECKSTACK_ARCH := $(SUBARCH)
1971else
1972CHECKSTACK_ARCH := $(ARCH)
1973endif
1974checkstack:
1975	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1976	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1977
1978kernelrelease:
1979	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1980
1981kernelversion:
1982	@echo $(KERNELVERSION)
1983
1984image_name:
1985	@echo $(KBUILD_IMAGE)
1986
1987quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1988      cmd_rmfiles = rm -rf $(rm-files)
1989
1990# read saved command lines for existing targets
1991existing-targets := $(wildcard $(sort $(targets)))
1992
1993-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1994
1995endif # config-build
1996endif # mixed-build
1997endif # need-sub-make
1998
1999PHONY += FORCE
2000FORCE:
2001
2002# Declare the contents of the PHONY variable as phony.  We keep that
2003# information in a variable so we can use it in if_changed and friends.
2004.PHONY: $(PHONY)
2005