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
483CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
484		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
485NOSTDINC_FLAGS :=
486CFLAGS_MODULE   =
487AFLAGS_MODULE   =
488LDFLAGS_MODULE  =
489CFLAGS_KERNEL	=
490AFLAGS_KERNEL	=
491LDFLAGS_vmlinux =
492
493# Use USERINCLUDE when you must reference the UAPI directories only.
494USERINCLUDE    := \
495		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
496		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
497		-I$(srctree)/include/uapi \
498		-I$(objtree)/include/generated/uapi \
499                -include $(srctree)/include/linux/compiler-version.h \
500                -include $(srctree)/include/linux/kconfig.h
501
502# Use LINUXINCLUDE when you must reference the include/ directory.
503# Needed to be compatible with the O= option
504LINUXINCLUDE    := \
505		-I$(srctree)/arch/$(SRCARCH)/include \
506		-I$(objtree)/arch/$(SRCARCH)/include/generated \
507		$(if $(building_out_of_srctree),-I$(srctree)/include) \
508		-I$(objtree)/include \
509		$(USERINCLUDE)
510
511KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
512KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
513		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
514		   -Werror=implicit-function-declaration -Werror=implicit-int \
515		   -Werror=return-type -Wno-format-security \
516		   -std=gnu89
517KBUILD_CPPFLAGS := -D__KERNEL__
518KBUILD_AFLAGS_KERNEL :=
519KBUILD_CFLAGS_KERNEL :=
520KBUILD_AFLAGS_MODULE  := -DMODULE
521KBUILD_CFLAGS_MODULE  := -DMODULE
522KBUILD_LDFLAGS_MODULE :=
523KBUILD_LDFLAGS :=
524CLANG_FLAGS :=
525
526export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
527export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
528export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
529export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
530export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
531
532export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
533export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
534export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
535export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
536export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
537
538# Files to ignore in find ... statements
539
540export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
541			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
542			  -prune -o
543export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
544			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
545
546# ===========================================================================
547# Rules shared between *config targets and build targets
548
549# Basic helpers built in scripts/basic/
550PHONY += scripts_basic
551scripts_basic:
552	$(Q)$(MAKE) $(build)=scripts/basic
553
554PHONY += outputmakefile
555ifdef building_out_of_srctree
556# Before starting out-of-tree build, make sure the source tree is clean.
557# outputmakefile generates a Makefile in the output directory, if using a
558# separate output directory. This allows convenient use of make in the
559# output directory.
560# At the same time when output Makefile generated, generate .gitignore to
561# ignore whole output directory
562
563quiet_cmd_makefile = GEN     Makefile
564      cmd_makefile = { \
565	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
566	echo "include $(srctree)/Makefile"; \
567	} > Makefile
568
569outputmakefile:
570	$(Q)if [ -f $(srctree)/.config -o \
571		 -d $(srctree)/include/config -o \
572		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
573		echo >&2 "***"; \
574		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
575		echo >&2 "*** in $(abs_srctree)";\
576		echo >&2 "***"; \
577		false; \
578	fi
579	$(Q)ln -fsn $(srctree) source
580	$(call cmd,makefile)
581	$(Q)test -e .gitignore || \
582	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
583endif
584
585# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
586# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
587# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
588# and from include/config/auto.conf.cmd to detect the compiler upgrade.
589CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
590
591ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
592include $(srctree)/scripts/Makefile.clang
593endif
594
595# Include this also for config targets because some architectures need
596# cc-cross-prefix to determine CROSS_COMPILE.
597ifdef need-compiler
598include $(srctree)/scripts/Makefile.compiler
599endif
600
601ifdef config-build
602# ===========================================================================
603# *config targets only - make sure prerequisites are updated, and descend
604# in scripts/kconfig to make the *config target
605
606# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
607# KBUILD_DEFCONFIG may point out an alternative default configuration
608# used for 'make defconfig'
609include $(srctree)/arch/$(SRCARCH)/Makefile
610export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
611
612config: outputmakefile scripts_basic FORCE
613	$(Q)$(MAKE) $(build)=scripts/kconfig $@
614
615%config: outputmakefile scripts_basic FORCE
616	$(Q)$(MAKE) $(build)=scripts/kconfig $@
617
618else #!config-build
619# ===========================================================================
620# Build targets only - this includes vmlinux, arch specific targets, clean
621# targets and others. In general all targets except *config targets.
622
623# If building an external module we do not care about the all: rule
624# but instead __all depend on modules
625PHONY += all
626ifeq ($(KBUILD_EXTMOD),)
627__all: all
628else
629__all: modules
630endif
631
632# Decide whether to build built-in, modular, or both.
633# Normally, just do built-in.
634
635KBUILD_MODULES :=
636KBUILD_BUILTIN := 1
637
638# If we have only "make modules", don't compile built-in objects.
639ifeq ($(MAKECMDGOALS),modules)
640  KBUILD_BUILTIN :=
641endif
642
643# If we have "make <whatever> modules", compile modules
644# in addition to whatever we do anyway.
645# Just "make" or "make all" shall build modules as well
646
647ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
648  KBUILD_MODULES := 1
649endif
650
651ifeq ($(MAKECMDGOALS),)
652  KBUILD_MODULES := 1
653endif
654
655export KBUILD_MODULES KBUILD_BUILTIN
656
657ifdef need-config
658include include/config/auto.conf
659endif
660
661ifeq ($(KBUILD_EXTMOD),)
662# Objects we will link into vmlinux / subdirs we need to visit
663core-y		:= init/ usr/ arch/$(SRCARCH)/
664drivers-y	:= drivers/ sound/
665drivers-$(CONFIG_SAMPLES) += samples/
666drivers-$(CONFIG_NET) += net/
667drivers-y	+= virt/
668libs-y		:= lib/
669endif # KBUILD_EXTMOD
670
671# The all: target is the default when no target is given on the
672# command line.
673# This allow a user to issue only 'make' to build a kernel including modules
674# Defaults to vmlinux, but the arch makefile usually adds further targets
675all: vmlinux
676
677CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
678ifdef CONFIG_CC_IS_GCC
679CFLAGS_GCOV	+= -fno-tree-loop-im
680endif
681export CFLAGS_GCOV
682
683# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
684ifdef CONFIG_FUNCTION_TRACER
685  CC_FLAGS_FTRACE := -pg
686endif
687
688ifdef CONFIG_CC_IS_GCC
689RETPOLINE_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-extern -mindirect-branch-register)
690RETPOLINE_VDSO_CFLAGS	:= $(call cc-option,-mindirect-branch=thunk-inline -mindirect-branch-register)
691endif
692ifdef CONFIG_CC_IS_CLANG
693RETPOLINE_CFLAGS	:= -mretpoline-external-thunk
694RETPOLINE_VDSO_CFLAGS	:= -mretpoline
695endif
696export RETPOLINE_CFLAGS
697export RETPOLINE_VDSO_CFLAGS
698
699include $(srctree)/arch/$(SRCARCH)/Makefile
700
701ifdef need-config
702ifdef may-sync-config
703# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
704# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
705# because some architectures define CROSS_COMPILE there.
706include include/config/auto.conf.cmd
707
708$(KCONFIG_CONFIG):
709	@echo >&2 '***'
710	@echo >&2 '*** Configuration file "$@" not found!'
711	@echo >&2 '***'
712	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
713	@echo >&2 '*** "make menuconfig" or "make xconfig").'
714	@echo >&2 '***'
715	@/bin/false
716
717# The actual configuration files used during the build are stored in
718# include/generated/ and include/config/. Update them if .config is newer than
719# include/config/auto.conf (which mirrors .config).
720#
721# This exploits the 'multi-target pattern rule' trick.
722# The syncconfig should be executed only once to make all the targets.
723# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
724#
725# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
726# so you cannot notice that Kconfig is waiting for the user input.
727%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
728	$(Q)$(kecho) "  SYNC    $@"
729	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
730else # !may-sync-config
731# External modules and some install targets need include/generated/autoconf.h
732# and include/config/auto.conf but do not care if they are up-to-date.
733# Use auto.conf to trigger the test
734PHONY += include/config/auto.conf
735
736include/config/auto.conf:
737	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
738	echo >&2;							\
739	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
740	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
741	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
742	echo >&2 ;							\
743	/bin/false)
744
745endif # may-sync-config
746endif # need-config
747
748KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
749KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
750KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
751KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
752KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
753
754ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
755KBUILD_CFLAGS += -O2
756else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
757KBUILD_CFLAGS += -O3
758else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
759KBUILD_CFLAGS += -Os
760endif
761
762# Tell gcc to never replace conditional load with a non-conditional one
763ifdef CONFIG_CC_IS_GCC
764# gcc-10 renamed --param=allow-store-data-races=0 to
765# -fno-allow-store-data-races.
766KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
767KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
768endif
769
770ifdef CONFIG_READABLE_ASM
771# Disable optimizations that make assembler listings hard to read.
772# reorder blocks reorders the control in the function
773# ipa clone creates specialized cloned functions
774# partial inlining inlines only parts of functions
775KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
776endif
777
778ifneq ($(CONFIG_FRAME_WARN),0)
779KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
780endif
781
782stackp-flags-y                                    := -fno-stack-protector
783stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
784stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
785
786KBUILD_CFLAGS += $(stackp-flags-y)
787
788KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
789KBUILD_CFLAGS += $(KBUILD_CFLAGS-y)
790
791ifdef CONFIG_CC_IS_CLANG
792KBUILD_CPPFLAGS += -Qunused-arguments
793# The kernel builds with '-std=gnu89' so use of GNU extensions is acceptable.
794KBUILD_CFLAGS += -Wno-gnu
795# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
796# source of a reference will be _MergedGlobals and not on of the whitelisted names.
797# See modpost pattern 2
798KBUILD_CFLAGS += -mno-global-merge
799else
800
801# Warn about unmarked fall-throughs in switch statement.
802# Disabled for clang while comment to attribute conversion happens and
803# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
804KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough=5,)
805# gcc inanely warns about local variables called 'main'
806KBUILD_CFLAGS += -Wno-main
807endif
808
809# These warnings generated too much noise in a regular build.
810# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
811KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
812KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
813
814ifdef CONFIG_FRAME_POINTER
815KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
816else
817# Some targets (ARM with Thumb2, for example), can't be built with frame
818# pointers.  For those, we don't have FUNCTION_TRACER automatically
819# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
820# incompatible with -fomit-frame-pointer with current GCC, so we don't use
821# -fomit-frame-pointer with FUNCTION_TRACER.
822ifndef CONFIG_FUNCTION_TRACER
823KBUILD_CFLAGS	+= -fomit-frame-pointer
824endif
825endif
826
827# Initialize all stack variables with a 0xAA pattern.
828ifdef CONFIG_INIT_STACK_ALL_PATTERN
829KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
830endif
831
832# Initialize all stack variables with a zero value.
833ifdef CONFIG_INIT_STACK_ALL_ZERO
834# Future support for zero initialization is still being debated, see
835# https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
836# renamed or dropped.
837KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
838KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
839endif
840
841# While VLAs have been removed, GCC produces unreachable stack probes
842# for the randomize_kstack_offset feature. Disable it for all compilers.
843KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
844
845# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
846ifdef CONFIG_ZERO_CALL_USED_REGS
847KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
848endif
849
850DEBUG_CFLAGS	:=
851
852ifdef CONFIG_DEBUG_INFO
853
854ifdef CONFIG_DEBUG_INFO_SPLIT
855DEBUG_CFLAGS	+= -gsplit-dwarf
856else
857DEBUG_CFLAGS	+= -g
858endif
859
860ifndef CONFIG_AS_IS_LLVM
861KBUILD_AFLAGS	+= -Wa,-gdwarf-2
862endif
863
864ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
865dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
866dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
867DEBUG_CFLAGS	+= -gdwarf-$(dwarf-version-y)
868endif
869
870ifdef CONFIG_DEBUG_INFO_REDUCED
871DEBUG_CFLAGS	+= -fno-var-tracking
872ifdef CONFIG_CC_IS_GCC
873DEBUG_CFLAGS	+= -femit-struct-debug-baseonly
874endif
875endif
876
877ifdef CONFIG_DEBUG_INFO_COMPRESSED
878DEBUG_CFLAGS	+= -gz=zlib
879KBUILD_AFLAGS	+= -gz=zlib
880KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
881endif
882
883endif # CONFIG_DEBUG_INFO
884
885KBUILD_CFLAGS += $(DEBUG_CFLAGS)
886export DEBUG_CFLAGS
887
888ifdef CONFIG_FUNCTION_TRACER
889ifdef CONFIG_FTRACE_MCOUNT_USE_CC
890  CC_FLAGS_FTRACE	+= -mrecord-mcount
891  ifdef CONFIG_HAVE_NOP_MCOUNT
892    ifeq ($(call cc-option-yn, -mnop-mcount),y)
893      CC_FLAGS_FTRACE	+= -mnop-mcount
894      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
895    endif
896  endif
897endif
898ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
899  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
900endif
901ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
902  ifdef CONFIG_HAVE_C_RECORDMCOUNT
903    BUILD_C_RECORDMCOUNT := y
904    export BUILD_C_RECORDMCOUNT
905  endif
906endif
907ifdef CONFIG_HAVE_FENTRY
908  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
909  ifeq ($(call cc-option-yn, -mfentry),y)
910    CC_FLAGS_FTRACE	+= -mfentry
911    CC_FLAGS_USING	+= -DCC_USING_FENTRY
912  endif
913endif
914export CC_FLAGS_FTRACE
915KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
916KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
917endif
918
919# We trigger additional mismatches with less inlining
920ifdef CONFIG_DEBUG_SECTION_MISMATCH
921KBUILD_CFLAGS += -fno-inline-functions-called-once
922endif
923
924ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
925KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
926LDFLAGS_vmlinux += --gc-sections
927endif
928
929ifdef CONFIG_SHADOW_CALL_STACK
930CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
931KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
932export CC_FLAGS_SCS
933endif
934
935ifdef CONFIG_LTO_CLANG
936ifdef CONFIG_LTO_CLANG_THIN
937CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
938KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
939else
940CC_FLAGS_LTO	:= -flto
941endif
942CC_FLAGS_LTO	+= -fvisibility=hidden
943
944# Limit inlining across translation units to reduce binary size
945KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
946
947# Check for frame size exceeding threshold during prolog/epilog insertion
948# when using lld < 13.0.0.
949ifneq ($(CONFIG_FRAME_WARN),0)
950ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
951KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
952endif
953endif
954endif
955
956ifdef CONFIG_LTO
957KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
958KBUILD_AFLAGS	+= -fno-lto
959export CC_FLAGS_LTO
960endif
961
962ifdef CONFIG_CFI_CLANG
963CC_FLAGS_CFI	:= -fsanitize=cfi \
964		   -fsanitize-cfi-cross-dso \
965		   -fno-sanitize-cfi-canonical-jump-tables \
966		   -fno-sanitize-trap=cfi \
967		   -fno-sanitize-blacklist
968
969ifdef CONFIG_CFI_PERMISSIVE
970CC_FLAGS_CFI	+= -fsanitize-recover=cfi
971endif
972
973# If LTO flags are filtered out, we must also filter out CFI.
974CC_FLAGS_LTO	+= $(CC_FLAGS_CFI)
975KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
976export CC_FLAGS_CFI
977endif
978
979ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
980KBUILD_CFLAGS += -falign-functions=64
981endif
982
983# arch Makefile may override CC so keep this after arch Makefile is included
984NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
985
986# warn about C99 declaration after statement
987KBUILD_CFLAGS += -Wdeclaration-after-statement
988
989# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
990KBUILD_CFLAGS += -Wvla
991
992# disable pointer signed / unsigned warnings in gcc 4.0
993KBUILD_CFLAGS += -Wno-pointer-sign
994
995# disable stringop warnings in gcc 8+
996KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
997
998# We'll want to enable this eventually, but it's not going away for 5.7 at least
999KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
1000KBUILD_CFLAGS += -Wno-array-bounds
1001KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1002
1003# Another good warning that we'll want to enable eventually
1004KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1005
1006# Enabled with W=2, disabled by default as noisy
1007ifdef CONFIG_CC_IS_GCC
1008KBUILD_CFLAGS += -Wno-maybe-uninitialized
1009endif
1010
1011# disable invalid "can't wrap" optimizations for signed / pointers
1012KBUILD_CFLAGS	+= -fno-strict-overflow
1013
1014# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1015KBUILD_CFLAGS  += -fno-stack-check
1016
1017# conserve stack if available
1018ifdef CONFIG_CC_IS_GCC
1019KBUILD_CFLAGS   += -fconserve-stack
1020endif
1021
1022# Prohibit date/time macros, which would make the build non-deterministic
1023KBUILD_CFLAGS   += -Werror=date-time
1024
1025# enforce correct pointer usage
1026KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1027
1028# Require designated initializers for all marked structures
1029KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1030
1031# change __FILE__ to the relative path from the srctree
1032KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1033
1034# include additional Makefiles when needed
1035include-y			:= scripts/Makefile.extrawarn
1036include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1037include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1038include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1039include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1040include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1041
1042include $(addprefix $(srctree)/, $(include-y))
1043
1044# scripts/Makefile.gcc-plugins is intentionally included last.
1045# Do not add $(call cc-option,...) below this line. When you build the kernel
1046# from the clean source tree, the GCC plugins do not exist at this point.
1047
1048# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1049KBUILD_CPPFLAGS += $(KCPPFLAGS)
1050KBUILD_AFLAGS   += $(KAFLAGS)
1051KBUILD_CFLAGS   += $(KCFLAGS)
1052
1053KBUILD_LDFLAGS_MODULE += --build-id=sha1
1054LDFLAGS_vmlinux += --build-id=sha1
1055
1056ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1057LDFLAGS_vmlinux	+= $(call ld-option, -X,)
1058endif
1059
1060ifeq ($(CONFIG_RELR),y)
1061LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1062endif
1063
1064# We never want expected sections to be placed heuristically by the
1065# linker. All sections should be explicitly named in the linker script.
1066ifdef CONFIG_LD_ORPHAN_WARN
1067LDFLAGS_vmlinux += --orphan-handling=warn
1068endif
1069
1070# Align the bit size of userspace programs with the kernel
1071KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1072KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1073
1074# make the checker run with the right architecture
1075CHECKFLAGS += --arch=$(ARCH)
1076
1077# insure the checker run with the right endianness
1078CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1079
1080# the checker needs the correct machine size
1081CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1082
1083# Default kernel image to build when no specific target is given.
1084# KBUILD_IMAGE may be overruled on the command line or
1085# set in the environment
1086# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1087# this default value
1088export KBUILD_IMAGE ?= vmlinux
1089
1090#
1091# INSTALL_PATH specifies where to place the updated kernel and system map
1092# images. Default is /boot, but you can set it to other values
1093export	INSTALL_PATH ?= /boot
1094
1095#
1096# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1097# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1098# an argument if needed. Otherwise it defaults to the kernel install path
1099#
1100export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1101
1102#
1103# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1104# relocations required by build roots.  This is not defined in the
1105# makefile but the argument can be passed to make if needed.
1106#
1107
1108MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1109export MODLIB
1110
1111PHONY += prepare0
1112
1113export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1114export MODORDER := $(extmod_prefix)modules.order
1115export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1116
1117ifeq ($(KBUILD_EXTMOD),)
1118core-y		+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1119
1120vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1121		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1122		     $(libs-y) $(libs-m)))
1123
1124vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1125		     $(patsubst %/,%,$(filter %/, $(core-) \
1126			$(drivers-) $(libs-))))
1127
1128subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1129			$(core-y) $(core-m) $(libs-y) $(libs-m) \
1130			$(drivers-y) $(drivers-m)))
1131
1132build-dirs	:= $(vmlinux-dirs)
1133clean-dirs	:= $(vmlinux-alldirs)
1134
1135# Externally visible symbols (used by link-vmlinux.sh)
1136KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1137KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1138ifdef CONFIG_MODULES
1139KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1140KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1141else
1142KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1143endif
1144KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1145
1146export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1147export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1148# used by scripts/Makefile.package
1149export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1150
1151vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1152
1153# Recurse until adjust_autoksyms.sh is satisfied
1154PHONY += autoksyms_recursive
1155ifdef CONFIG_TRIM_UNUSED_KSYMS
1156# For the kernel to actually contain only the needed exported symbols,
1157# we have to build modules as well to determine what those symbols are.
1158# (this can be evaluated only once include/config/auto.conf has been included)
1159KBUILD_MODULES := 1
1160
1161autoksyms_recursive: descend modules.order
1162	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1163	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1164endif
1165
1166autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1167
1168quiet_cmd_autoksyms_h = GEN     $@
1169      cmd_autoksyms_h = mkdir -p $(dir $@); \
1170			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1171
1172$(autoksyms_h):
1173	$(call cmd,autoksyms_h)
1174
1175ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1176
1177# Final link of vmlinux with optional arch pass after final link
1178cmd_link-vmlinux =                                                 \
1179	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1180	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1181
1182vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1183	+$(call if_changed_dep,link-vmlinux)
1184
1185targets := vmlinux
1186
1187# The actual objects are generated when descending,
1188# make sure no implicit rule kicks in
1189$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1190
1191filechk_kernel.release = \
1192	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1193
1194# Store (new) KERNELRELEASE string in include/config/kernel.release
1195include/config/kernel.release: FORCE
1196	$(call filechk,kernel.release)
1197
1198# Additional helpers built in scripts/
1199# Carefully list dependencies so we do not try to build scripts twice
1200# in parallel
1201PHONY += scripts
1202scripts: scripts_basic scripts_dtc
1203	$(Q)$(MAKE) $(build)=$(@)
1204
1205# Things we need to do before we recursively start building the kernel
1206# or the modules are listed in "prepare".
1207# A multi level approach is used. prepareN is processed before prepareN-1.
1208# archprepare is used in arch Makefiles and when processed asm symlink,
1209# version.h and scripts_basic is processed / created.
1210
1211PHONY += prepare archprepare
1212
1213archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1214	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1215	include/generated/autoconf.h remove-stale-files
1216
1217prepare0: archprepare
1218	$(Q)$(MAKE) $(build)=scripts/mod
1219	$(Q)$(MAKE) $(build)=.
1220
1221# All the preparing..
1222prepare: prepare0
1223
1224PHONY += remove-stale-files
1225remove-stale-files:
1226	$(Q)$(srctree)/scripts/remove-stale-files
1227
1228# Support for using generic headers in asm-generic
1229asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1230
1231PHONY += asm-generic uapi-asm-generic
1232asm-generic: uapi-asm-generic
1233	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1234	generic=include/asm-generic
1235uapi-asm-generic:
1236	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1237	generic=include/uapi/asm-generic
1238
1239# Generate some files
1240# ---------------------------------------------------------------------------
1241
1242# KERNELRELEASE can change from a few different places, meaning version.h
1243# needs to be updated, so this check is forced on all builds
1244
1245uts_len := 64
1246define filechk_utsrelease.h
1247	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1248	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1249	  exit 1;                                                         \
1250	fi;                                                               \
1251	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1252endef
1253
1254define filechk_version.h
1255	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1256		echo \#define LINUX_VERSION_CODE $(shell                 \
1257		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1258	else                                                             \
1259		echo \#define LINUX_VERSION_CODE $(shell                 \
1260		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1261	fi;                                                              \
1262	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1263	((c) > 255 ? 255 : (c)))';                                       \
1264	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1265	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1266	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1267endef
1268
1269$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1270$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1271$(version_h): FORCE
1272	$(call filechk,version.h)
1273
1274include/generated/utsrelease.h: include/config/kernel.release FORCE
1275	$(call filechk,utsrelease.h)
1276
1277PHONY += headerdep
1278headerdep:
1279	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1280	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1281
1282# ---------------------------------------------------------------------------
1283# Kernel headers
1284
1285#Default location for installed headers
1286export INSTALL_HDR_PATH = $(objtree)/usr
1287
1288quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1289      cmd_headers_install = \
1290	mkdir -p $(INSTALL_HDR_PATH); \
1291	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1292	usr/include $(INSTALL_HDR_PATH)
1293
1294PHONY += headers_install
1295headers_install: headers
1296	$(call cmd,headers_install)
1297
1298PHONY += archheaders archscripts
1299
1300hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1301
1302PHONY += headers
1303headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1304	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1305	  $(error Headers not exportable for the $(SRCARCH) architecture))
1306	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1307	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1308
1309# Deprecated. It is no-op now.
1310PHONY += headers_check
1311headers_check:
1312	@echo >&2 "=================== WARNING ==================="
1313	@echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1314	@echo >&2 "and will be removed after Linux 5.15 release."
1315	@echo >&2 "Please remove headers_check from your scripts."
1316	@echo >&2 "==============================================="
1317
1318ifdef CONFIG_HEADERS_INSTALL
1319prepare: headers
1320endif
1321
1322PHONY += scripts_unifdef
1323scripts_unifdef: scripts_basic
1324	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1325
1326# ---------------------------------------------------------------------------
1327# Install
1328
1329# Many distributions have the custom install script, /sbin/installkernel.
1330# If DKMS is installed, 'make install' will eventually recuses back
1331# to the this Makefile to build and install external modules.
1332# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1333
1334install: sub_make_done :=
1335
1336# ---------------------------------------------------------------------------
1337# Tools
1338
1339ifdef CONFIG_STACK_VALIDATION
1340prepare: tools/objtool
1341endif
1342
1343ifdef CONFIG_BPF
1344ifdef CONFIG_DEBUG_INFO_BTF
1345prepare: tools/bpf/resolve_btfids
1346endif
1347endif
1348
1349PHONY += resolve_btfids_clean
1350
1351resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1352
1353# tools/bpf/resolve_btfids directory might not exist
1354# in output directory, skip its clean in that case
1355resolve_btfids_clean:
1356ifneq ($(wildcard $(resolve_btfids_O)),)
1357	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1358endif
1359
1360# Clear a bunch of variables before executing the submake
1361ifeq ($(quiet),silent_)
1362tools_silent=s
1363endif
1364
1365tools/: FORCE
1366	$(Q)mkdir -p $(objtree)/tools
1367	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
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
1373# ---------------------------------------------------------------------------
1374# Kernel selftest
1375
1376PHONY += kselftest
1377kselftest:
1378	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1379
1380kselftest-%: FORCE
1381	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1382
1383PHONY += kselftest-merge
1384kselftest-merge:
1385	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1386	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1387		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1388	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1389
1390# ---------------------------------------------------------------------------
1391# Devicetree files
1392
1393ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1394dtstree := arch/$(SRCARCH)/boot/dts
1395endif
1396
1397ifneq ($(dtstree),)
1398
1399%.dtb: include/config/kernel.release scripts_dtc
1400	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1401
1402%.dtbo: include/config/kernel.release scripts_dtc
1403	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1404
1405PHONY += dtbs dtbs_install dtbs_check
1406dtbs: include/config/kernel.release scripts_dtc
1407	$(Q)$(MAKE) $(build)=$(dtstree)
1408
1409ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1410export CHECK_DTBS=y
1411dtbs: dt_binding_check
1412endif
1413
1414dtbs_check: dtbs
1415
1416dtbs_install:
1417	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1418
1419ifdef CONFIG_OF_EARLY_FLATTREE
1420all: dtbs
1421endif
1422
1423endif
1424
1425PHONY += scripts_dtc
1426scripts_dtc: scripts_basic
1427	$(Q)$(MAKE) $(build)=scripts/dtc
1428
1429ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1430export CHECK_DT_BINDING=y
1431endif
1432
1433PHONY += dt_binding_check
1434dt_binding_check: scripts_dtc
1435	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1436
1437# ---------------------------------------------------------------------------
1438# Modules
1439
1440ifdef CONFIG_MODULES
1441
1442# By default, build modules as well
1443
1444all: modules
1445
1446# When we're building modules with modversions, we need to consider
1447# the built-in objects during the descend as well, in order to
1448# make sure the checksums are up to date before we record them.
1449ifdef CONFIG_MODVERSIONS
1450  KBUILD_BUILTIN := 1
1451endif
1452
1453# Build modules
1454#
1455# A module can be listed more than once in obj-m resulting in
1456# duplicate lines in modules.order files.  Those are removed
1457# using awk while concatenating to the final file.
1458
1459PHONY += modules
1460modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1461
1462cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1463
1464modules.order: $(subdir-modorder) FORCE
1465	$(call if_changed,modules_order)
1466
1467targets += modules.order
1468
1469# Target to prepare building external modules
1470PHONY += modules_prepare
1471modules_prepare: prepare
1472	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1473
1474export modules_sign_only :=
1475
1476ifeq ($(CONFIG_MODULE_SIG),y)
1477PHONY += modules_sign
1478modules_sign: modules_install
1479	@:
1480
1481# modules_sign is a subset of modules_install.
1482# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1483ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1484modules_sign_only := y
1485endif
1486endif
1487
1488modinst_pre :=
1489ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1490modinst_pre := __modinst_pre
1491endif
1492
1493modules_install: $(modinst_pre)
1494PHONY += __modinst_pre
1495__modinst_pre:
1496	@rm -rf $(MODLIB)/kernel
1497	@rm -f $(MODLIB)/source
1498	@mkdir -p $(MODLIB)/kernel
1499	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1500	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1501		rm -f $(MODLIB)/build ; \
1502		ln -s $(CURDIR) $(MODLIB)/build ; \
1503	fi
1504	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1505	@cp -f modules.builtin $(MODLIB)/
1506	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1507
1508endif # CONFIG_MODULES
1509
1510###
1511# Cleaning is done on three levels.
1512# make clean     Delete most generated files
1513#                Leave enough to build external modules
1514# make mrproper  Delete the current configuration, and all generated files
1515# make distclean Remove editor backup files, patch leftover files and the like
1516
1517# Directories & files removed with 'make clean'
1518CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1519	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1520	       compile_commands.json .thinlto-cache
1521
1522# Directories & files removed with 'make mrproper'
1523MRPROPER_FILES += include/config include/generated          \
1524		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1525		  debian snap tar-install \
1526		  .config .config.old .version \
1527		  Module.symvers \
1528		  certs/signing_key.pem certs/signing_key.x509 \
1529		  certs/x509.genkey \
1530		  vmlinux-gdb.py \
1531		  *.spec
1532
1533# clean - Delete most, but leave enough to build external modules
1534#
1535clean: rm-files := $(CLEAN_FILES)
1536
1537PHONY += archclean vmlinuxclean
1538
1539vmlinuxclean:
1540	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1541	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1542
1543clean: archclean vmlinuxclean resolve_btfids_clean
1544
1545# mrproper - Delete all generated files, including .config
1546#
1547mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1548mrproper-dirs      := $(addprefix _mrproper_,scripts)
1549
1550PHONY += $(mrproper-dirs) mrproper
1551$(mrproper-dirs):
1552	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1553
1554mrproper: clean $(mrproper-dirs)
1555	$(call cmd,rmfiles)
1556
1557# distclean
1558#
1559PHONY += distclean
1560
1561distclean: mrproper
1562	@find . $(RCS_FIND_IGNORE) \
1563		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1564		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1565		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1566		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1567		-type f -print | xargs rm -f
1568
1569
1570# Packaging of the kernel to various formats
1571# ---------------------------------------------------------------------------
1572
1573%src-pkg: FORCE
1574	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1575%pkg: include/config/kernel.release FORCE
1576	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1577
1578# Brief documentation of the typical targets used
1579# ---------------------------------------------------------------------------
1580
1581boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1582boards := $(sort $(notdir $(boards)))
1583board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1584board-dirs := $(sort $(notdir $(board-dirs:/=)))
1585
1586PHONY += help
1587help:
1588	@echo  'Cleaning targets:'
1589	@echo  '  clean		  - Remove most generated files but keep the config and'
1590	@echo  '                    enough build support to build external modules'
1591	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1592	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1593	@echo  ''
1594	@echo  'Configuration targets:'
1595	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1596	@echo  ''
1597	@echo  'Other generic targets:'
1598	@echo  '  all		  - Build all targets marked with [*]'
1599	@echo  '* vmlinux	  - Build the bare kernel'
1600	@echo  '* modules	  - Build all modules'
1601	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1602	@echo  '  dir/            - Build all files in dir and below'
1603	@echo  '  dir/file.[ois]  - Build specified target only'
1604	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1605	@echo  '                    (requires compiler support for LLVM assembly generation)'
1606	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1607	@echo  '                    (requires a recent binutils and recent build (System.map))'
1608	@echo  '  dir/file.ko     - Build module including final link'
1609	@echo  '  modules_prepare - Set up for building external modules'
1610	@echo  '  tags/TAGS	  - Generate tags file for editors'
1611	@echo  '  cscope	  - Generate cscope index'
1612	@echo  '  gtags           - Generate GNU GLOBAL index'
1613	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1614	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1615	@echo  '  image_name	  - Output the image name (use with make -s)'
1616	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1617	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1618	 echo  ''
1619	@echo  'Static analysers:'
1620	@echo  '  checkstack      - Generate a list of stack hogs'
1621	@echo  '  versioncheck    - Sanity check on version.h usage'
1622	@echo  '  includecheck    - Check for duplicate included header files'
1623	@echo  '  export_report   - List the usages of all exported symbols'
1624	@echo  '  headerdep       - Detect inclusion cycles in headers'
1625	@echo  '  coccicheck      - Check with Coccinelle'
1626	@echo  '  clang-analyzer  - Check with clang static analyzer'
1627	@echo  '  clang-tidy      - Check with clang-tidy'
1628	@echo  ''
1629	@echo  'Tools:'
1630	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1631	@echo  ''
1632	@echo  'Kernel selftest:'
1633	@echo  '  kselftest         - Build and run kernel selftest'
1634	@echo  '                      Build, install, and boot kernel before'
1635	@echo  '                      running kselftest on it'
1636	@echo  '                      Run as root for full coverage'
1637	@echo  '  kselftest-all     - Build kernel selftest'
1638	@echo  '  kselftest-install - Build and install kernel selftest'
1639	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1640	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1641	@echo  '		      kselftest to existing .config.'
1642	@echo  ''
1643	@$(if $(dtstree), \
1644		echo 'Devicetree:'; \
1645		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1646		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1647		echo '  dt_binding_check - Validate device tree binding documents'; \
1648		echo '  dtbs_check       - Validate device tree source files';\
1649		echo '')
1650
1651	@echo 'Userspace tools targets:'
1652	@echo '  use "make tools/help"'
1653	@echo '  or  "cd tools; make help"'
1654	@echo  ''
1655	@echo  'Kernel packaging:'
1656	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1657	@echo  ''
1658	@echo  'Documentation targets:'
1659	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1660	@echo  ''
1661	@echo  'Architecture specific targets ($(SRCARCH)):'
1662	@$(if $(archhelp),$(archhelp),\
1663		echo '  No architecture specific help defined for $(SRCARCH)')
1664	@echo  ''
1665	@$(if $(boards), \
1666		$(foreach b, $(boards), \
1667		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1668		echo '')
1669	@$(if $(board-dirs), \
1670		$(foreach b, $(board-dirs), \
1671		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1672		printf "  %-16s - Show all of the above\\n" help-boards; \
1673		echo '')
1674
1675	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1676	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1677	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1678	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1679	@echo  '                       (sparse by default)'
1680	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1681	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1682	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1683	@echo  '		1: warnings which may be relevant and do not occur too often'
1684	@echo  '		2: warnings which occur quite often but may still be relevant'
1685	@echo  '		3: more obscure warnings, can most likely be ignored'
1686	@echo  '		Multiple levels can be combined with W=12 or W=123'
1687	@echo  ''
1688	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1689	@echo  'For further info see the ./README file'
1690
1691
1692help-board-dirs := $(addprefix help-,$(board-dirs))
1693
1694help-boards: $(help-board-dirs)
1695
1696boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1697
1698$(help-board-dirs): help-%:
1699	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1700	@$(if $(boards-per-dir), \
1701		$(foreach b, $(boards-per-dir), \
1702		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1703		echo '')
1704
1705
1706# Documentation targets
1707# ---------------------------------------------------------------------------
1708DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1709	       linkcheckdocs dochelp refcheckdocs
1710PHONY += $(DOC_TARGETS)
1711$(DOC_TARGETS):
1712	$(Q)$(MAKE) $(build)=Documentation $@
1713
1714# Misc
1715# ---------------------------------------------------------------------------
1716
1717PHONY += scripts_gdb
1718scripts_gdb: prepare0
1719	$(Q)$(MAKE) $(build)=scripts/gdb
1720	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1721
1722ifdef CONFIG_GDB_SCRIPTS
1723all: scripts_gdb
1724endif
1725
1726else # KBUILD_EXTMOD
1727
1728###
1729# External module support.
1730# When building external modules the kernel used as basis is considered
1731# read-only, and no consistency checks are made and the make
1732# system is not used on the basis kernel. If updates are required
1733# in the basis kernel ordinary make commands (without M=...) must be used.
1734
1735# We are always building only modules.
1736KBUILD_BUILTIN :=
1737KBUILD_MODULES := 1
1738
1739build-dirs := $(KBUILD_EXTMOD)
1740$(MODORDER): descend
1741	@:
1742
1743compile_commands.json: $(extmod_prefix)compile_commands.json
1744PHONY += compile_commands.json
1745
1746clean-dirs := $(KBUILD_EXTMOD)
1747clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1748	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1749
1750PHONY += prepare
1751# now expand this into a simple variable to reduce the cost of shell evaluations
1752prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1753prepare:
1754	@if [ "$(CC_VERSION_TEXT)" != $(CONFIG_CC_VERSION_TEXT) ]; then \
1755		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1756		echo >&2 "  The kernel was built by: "$(CONFIG_CC_VERSION_TEXT); \
1757		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1758	fi
1759
1760PHONY += help
1761help:
1762	@echo  '  Building external modules.'
1763	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1764	@echo  ''
1765	@echo  '  modules         - default target, build the module(s)'
1766	@echo  '  modules_install - install the module'
1767	@echo  '  clean           - remove generated files in module directory only'
1768	@echo  ''
1769
1770# no-op for external module builds
1771PHONY += modules_prepare
1772
1773endif # KBUILD_EXTMOD
1774
1775# ---------------------------------------------------------------------------
1776# Modules
1777
1778PHONY += modules modules_install
1779
1780ifdef CONFIG_MODULES
1781
1782modules: modules_check
1783	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1784
1785PHONY += modules_check
1786modules_check: $(MODORDER)
1787	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1788
1789quiet_cmd_depmod = DEPMOD  $(MODLIB)
1790      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1791                   $(KERNELRELEASE)
1792
1793modules_install:
1794	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1795	$(call cmd,depmod)
1796
1797else # CONFIG_MODULES
1798
1799# Modules not configured
1800# ---------------------------------------------------------------------------
1801
1802modules modules_install:
1803	@echo >&2 '***'
1804	@echo >&2 '*** The present kernel configuration has modules disabled.'
1805	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1806	@echo >&2 '*** to enable CONFIG_MODULES.'
1807	@echo >&2 '***'
1808	@exit 1
1809
1810endif # CONFIG_MODULES
1811
1812# Single targets
1813# ---------------------------------------------------------------------------
1814# To build individual files in subdirectories, you can do like this:
1815#
1816#   make foo/bar/baz.s
1817#
1818# The supported suffixes for single-target are listed in 'single-targets'
1819#
1820# To build only under specific subdirectories, you can do like this:
1821#
1822#   make foo/bar/baz/
1823
1824ifdef single-build
1825
1826# .ko is special because modpost is needed
1827single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1828single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1829
1830$(single-ko): single_modpost
1831	@:
1832$(single-no-ko): descend
1833	@:
1834
1835ifeq ($(KBUILD_EXTMOD),)
1836# For the single build of in-tree modules, use a temporary file to avoid
1837# the situation of modules_install installing an invalid modules.order.
1838MODORDER := .modules.tmp
1839endif
1840
1841PHONY += single_modpost
1842single_modpost: $(single-no-ko) modules_prepare
1843	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1844	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1845
1846KBUILD_MODULES := 1
1847
1848export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1849
1850# trim unrelated directories
1851build-dirs := $(foreach d, $(build-dirs), \
1852			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1853
1854endif
1855
1856ifndef CONFIG_MODULES
1857KBUILD_MODULES :=
1858endif
1859
1860# Handle descending into subdirectories listed in $(build-dirs)
1861# Preset locale variables to speed up the build process. Limit locale
1862# tweaks to this spot to avoid wrong language settings when running
1863# make menuconfig etc.
1864# Error messages still appears in the original language
1865PHONY += descend $(build-dirs)
1866descend: $(build-dirs)
1867$(build-dirs): prepare
1868	$(Q)$(MAKE) $(build)=$@ \
1869	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1870	need-builtin=1 need-modorder=1
1871
1872clean-dirs := $(addprefix _clean_, $(clean-dirs))
1873PHONY += $(clean-dirs) clean
1874$(clean-dirs):
1875	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1876
1877clean: $(clean-dirs)
1878	$(call cmd,rmfiles)
1879	@find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1880		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1881		-o -name '*.ko.*' \
1882		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1883		-o -name '*.dwo' -o -name '*.lst' \
1884		-o -name '*.su' -o -name '*.mod' \
1885		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1886		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1887		-o -name '*.asn1.[ch]' \
1888		-o -name '*.symtypes' -o -name 'modules.order' \
1889		-o -name '.tmp_*.o.*' \
1890		-o -name '*.c.[012]*.*' \
1891		-o -name '*.ll' \
1892		-o -name '*.gcno' \
1893		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
1894
1895# Generate tags for editors
1896# ---------------------------------------------------------------------------
1897quiet_cmd_tags = GEN     $@
1898      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1899
1900tags TAGS cscope gtags: FORCE
1901	$(call cmd,tags)
1902
1903# Script to generate missing namespace dependencies
1904# ---------------------------------------------------------------------------
1905
1906PHONY += nsdeps
1907nsdeps: export KBUILD_NSDEPS=1
1908nsdeps: modules
1909	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1910
1911# Clang Tooling
1912# ---------------------------------------------------------------------------
1913
1914quiet_cmd_gen_compile_commands = GEN     $@
1915      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1916
1917$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1918	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1919	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1920	$(call if_changed,gen_compile_commands)
1921
1922targets += $(extmod_prefix)compile_commands.json
1923
1924PHONY += clang-tidy clang-analyzer
1925
1926ifdef CONFIG_CC_IS_CLANG
1927quiet_cmd_clang_tools = CHECK   $<
1928      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1929
1930clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1931	$(call cmd,clang_tools)
1932else
1933clang-tidy clang-analyzer:
1934	@echo "$@ requires CC=clang" >&2
1935	@false
1936endif
1937
1938# Scripts to check various things for consistency
1939# ---------------------------------------------------------------------------
1940
1941PHONY += includecheck versioncheck coccicheck export_report
1942
1943includecheck:
1944	find $(srctree)/* $(RCS_FIND_IGNORE) \
1945		-name '*.[hcS]' -type f -print | sort \
1946		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1947
1948versioncheck:
1949	find $(srctree)/* $(RCS_FIND_IGNORE) \
1950		-name '*.[hcS]' -type f -print | sort \
1951		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1952
1953coccicheck:
1954	$(Q)$(BASH) $(srctree)/scripts/$@
1955
1956export_report:
1957	$(PERL) $(srctree)/scripts/export_report.pl
1958
1959PHONY += checkstack kernelrelease kernelversion image_name
1960
1961# UML needs a little special treatment here.  It wants to use the host
1962# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1963# else wants $(ARCH), including people doing cross-builds, which means
1964# that $(SUBARCH) doesn't work here.
1965ifeq ($(ARCH), um)
1966CHECKSTACK_ARCH := $(SUBARCH)
1967else
1968CHECKSTACK_ARCH := $(ARCH)
1969endif
1970checkstack:
1971	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1972	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1973
1974kernelrelease:
1975	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1976
1977kernelversion:
1978	@echo $(KERNELVERSION)
1979
1980image_name:
1981	@echo $(KBUILD_IMAGE)
1982
1983quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1984      cmd_rmfiles = rm -rf $(rm-files)
1985
1986# read saved command lines for existing targets
1987existing-targets := $(wildcard $(sort $(targets)))
1988
1989-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1990
1991endif # config-build
1992endif # mixed-build
1993endif # need-sub-make
1994
1995PHONY += FORCE
1996FORCE:
1997
1998# Declare the contents of the PHONY variable as phony.  We keep that
1999# information in a variable so we can use it in if_changed and friends.
2000.PHONY: $(PHONY)
2001