xref: /linux/Makefile (revision b4a5ea09b29371c2e6a10783faa3593428404343)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 17
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Superb Owl
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),)
427ifneq ($(filter %/,$(LLVM)),)
428LLVM_PREFIX := $(LLVM)
429else ifneq ($(filter -%,$(LLVM)),)
430LLVM_SUFFIX := $(LLVM)
431endif
432
433HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
434HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
435else
436HOSTCC	= gcc
437HOSTCXX	= g++
438endif
439
440KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
441			 -O2 -fomit-frame-pointer -std=gnu11 \
442			 -Wdeclaration-after-statement
443KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
444KBUILD_USERLDFLAGS := $(USERLDFLAGS)
445
446KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
447KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
448KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
449KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
450
451# Make variables (CC, etc...)
452CPP		= $(CC) -E
453ifneq ($(LLVM),)
454CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
455LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
456AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
457NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
458OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
459OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
460READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
461STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
462else
463CC		= $(CROSS_COMPILE)gcc
464LD		= $(CROSS_COMPILE)ld
465AR		= $(CROSS_COMPILE)ar
466NM		= $(CROSS_COMPILE)nm
467OBJCOPY		= $(CROSS_COMPILE)objcopy
468OBJDUMP		= $(CROSS_COMPILE)objdump
469READELF		= $(CROSS_COMPILE)readelf
470STRIP		= $(CROSS_COMPILE)strip
471endif
472PAHOLE		= pahole
473RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
474LEX		= flex
475YACC		= bison
476AWK		= awk
477INSTALLKERNEL  := installkernel
478DEPMOD		= depmod
479PERL		= perl
480PYTHON3		= python3
481CHECK		= sparse
482BASH		= bash
483KGZIP		= gzip
484KBZIP2		= bzip2
485KLZOP		= lzop
486LZMA		= lzma
487LZ4		= lz4c
488XZ		= xz
489ZSTD		= zstd
490
491PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
492
493CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
494		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
495NOSTDINC_FLAGS :=
496CFLAGS_MODULE   =
497AFLAGS_MODULE   =
498LDFLAGS_MODULE  =
499CFLAGS_KERNEL	=
500AFLAGS_KERNEL	=
501LDFLAGS_vmlinux =
502
503# Use USERINCLUDE when you must reference the UAPI directories only.
504USERINCLUDE    := \
505		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
506		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
507		-I$(srctree)/include/uapi \
508		-I$(objtree)/include/generated/uapi \
509                -include $(srctree)/include/linux/compiler-version.h \
510                -include $(srctree)/include/linux/kconfig.h
511
512# Use LINUXINCLUDE when you must reference the include/ directory.
513# Needed to be compatible with the O= option
514LINUXINCLUDE    := \
515		-I$(srctree)/arch/$(SRCARCH)/include \
516		-I$(objtree)/arch/$(SRCARCH)/include/generated \
517		$(if $(building_out_of_srctree),-I$(srctree)/include) \
518		-I$(objtree)/include \
519		$(USERINCLUDE)
520
521KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
522KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
523		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
524		   -Werror=implicit-function-declaration -Werror=implicit-int \
525		   -Werror=return-type -Wno-format-security \
526		   -std=gnu11
527KBUILD_CPPFLAGS := -D__KERNEL__
528KBUILD_AFLAGS_KERNEL :=
529KBUILD_CFLAGS_KERNEL :=
530KBUILD_AFLAGS_MODULE  := -DMODULE
531KBUILD_CFLAGS_MODULE  := -DMODULE
532KBUILD_LDFLAGS_MODULE :=
533KBUILD_LDFLAGS :=
534CLANG_FLAGS :=
535
536export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
537export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
538export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
539export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
540export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
541export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
542
543export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
544export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
545export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
546export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
547export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
548export PAHOLE_FLAGS
549
550# Files to ignore in find ... statements
551
552export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
553			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
554			  -prune -o
555export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
556			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
557
558# ===========================================================================
559# Rules shared between *config targets and build targets
560
561# Basic helpers built in scripts/basic/
562PHONY += scripts_basic
563scripts_basic:
564	$(Q)$(MAKE) $(build)=scripts/basic
565
566PHONY += outputmakefile
567ifdef building_out_of_srctree
568# Before starting out-of-tree build, make sure the source tree is clean.
569# outputmakefile generates a Makefile in the output directory, if using a
570# separate output directory. This allows convenient use of make in the
571# output directory.
572# At the same time when output Makefile generated, generate .gitignore to
573# ignore whole output directory
574
575quiet_cmd_makefile = GEN     Makefile
576      cmd_makefile = { \
577	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
578	echo "include $(srctree)/Makefile"; \
579	} > Makefile
580
581outputmakefile:
582	$(Q)if [ -f $(srctree)/.config -o \
583		 -d $(srctree)/include/config -o \
584		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
585		echo >&2 "***"; \
586		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
587		echo >&2 "*** in $(abs_srctree)";\
588		echo >&2 "***"; \
589		false; \
590	fi
591	$(Q)ln -fsn $(srctree) source
592	$(call cmd,makefile)
593	$(Q)test -e .gitignore || \
594	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
595endif
596
597# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
598# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
599# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
600# and from include/config/auto.conf.cmd to detect the compiler upgrade.
601CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
602
603ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
604include $(srctree)/scripts/Makefile.clang
605endif
606
607# Include this also for config targets because some architectures need
608# cc-cross-prefix to determine CROSS_COMPILE.
609ifdef need-compiler
610include $(srctree)/scripts/Makefile.compiler
611endif
612
613ifdef config-build
614# ===========================================================================
615# *config targets only - make sure prerequisites are updated, and descend
616# in scripts/kconfig to make the *config target
617
618# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
619# KBUILD_DEFCONFIG may point out an alternative default configuration
620# used for 'make defconfig'
621include $(srctree)/arch/$(SRCARCH)/Makefile
622export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
623
624config: outputmakefile scripts_basic FORCE
625	$(Q)$(MAKE) $(build)=scripts/kconfig $@
626
627%config: outputmakefile scripts_basic FORCE
628	$(Q)$(MAKE) $(build)=scripts/kconfig $@
629
630else #!config-build
631# ===========================================================================
632# Build targets only - this includes vmlinux, arch specific targets, clean
633# targets and others. In general all targets except *config targets.
634
635# If building an external module we do not care about the all: rule
636# but instead __all depend on modules
637PHONY += all
638ifeq ($(KBUILD_EXTMOD),)
639__all: all
640else
641__all: modules
642endif
643
644# Decide whether to build built-in, modular, or both.
645# Normally, just do built-in.
646
647KBUILD_MODULES :=
648KBUILD_BUILTIN := 1
649
650# If we have only "make modules", don't compile built-in objects.
651ifeq ($(MAKECMDGOALS),modules)
652  KBUILD_BUILTIN :=
653endif
654
655# If we have "make <whatever> modules", compile modules
656# in addition to whatever we do anyway.
657# Just "make" or "make all" shall build modules as well
658
659ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
660  KBUILD_MODULES := 1
661endif
662
663ifeq ($(MAKECMDGOALS),)
664  KBUILD_MODULES := 1
665endif
666
667export KBUILD_MODULES KBUILD_BUILTIN
668
669ifdef need-config
670include include/config/auto.conf
671endif
672
673ifeq ($(KBUILD_EXTMOD),)
674# Objects we will link into vmlinux / subdirs we need to visit
675core-y		:= init/ usr/ arch/$(SRCARCH)/
676drivers-y	:= drivers/ sound/
677drivers-$(CONFIG_SAMPLES) += samples/
678drivers-$(CONFIG_NET) += net/
679drivers-y	+= virt/
680libs-y		:= lib/
681endif # KBUILD_EXTMOD
682
683# The all: target is the default when no target is given on the
684# command line.
685# This allow a user to issue only 'make' to build a kernel including modules
686# Defaults to vmlinux, but the arch makefile usually adds further targets
687all: vmlinux
688
689CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
690ifdef CONFIG_CC_IS_GCC
691CFLAGS_GCOV	+= -fno-tree-loop-im
692endif
693export CFLAGS_GCOV
694
695# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
696ifdef CONFIG_FUNCTION_TRACER
697  CC_FLAGS_FTRACE := -pg
698endif
699
700include $(srctree)/arch/$(SRCARCH)/Makefile
701
702ifdef need-config
703ifdef may-sync-config
704# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
705# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
706# because some architectures define CROSS_COMPILE there.
707include include/config/auto.conf.cmd
708
709$(KCONFIG_CONFIG):
710	@echo >&2 '***'
711	@echo >&2 '*** Configuration file "$@" not found!'
712	@echo >&2 '***'
713	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
714	@echo >&2 '*** "make menuconfig" or "make xconfig").'
715	@echo >&2 '***'
716	@/bin/false
717
718# The actual configuration files used during the build are stored in
719# include/generated/ and include/config/. Update them if .config is newer than
720# include/config/auto.conf (which mirrors .config).
721#
722# This exploits the 'multi-target pattern rule' trick.
723# The syncconfig should be executed only once to make all the targets.
724# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
725#
726# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
727# so you cannot notice that Kconfig is waiting for the user input.
728%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
729	$(Q)$(kecho) "  SYNC    $@"
730	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
731else # !may-sync-config
732# External modules and some install targets need include/generated/autoconf.h
733# and include/config/auto.conf but do not care if they are up-to-date.
734# Use auto.conf to trigger the test
735PHONY += include/config/auto.conf
736
737include/config/auto.conf:
738	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
739	echo >&2;							\
740	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
741	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
742	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
743	echo >&2 ;							\
744	/bin/false)
745
746endif # may-sync-config
747endif # need-config
748
749KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
750KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
751KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
752KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
753KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
754
755ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
756KBUILD_CFLAGS += -O2
757else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
758KBUILD_CFLAGS += -O3
759else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
760KBUILD_CFLAGS += -Os
761endif
762
763# Tell gcc to never replace conditional load with a non-conditional one
764ifdef CONFIG_CC_IS_GCC
765# gcc-10 renamed --param=allow-store-data-races=0 to
766# -fno-allow-store-data-races.
767KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
768KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
769endif
770
771ifdef CONFIG_READABLE_ASM
772# Disable optimizations that make assembler listings hard to read.
773# reorder blocks reorders the control in the function
774# ipa clone creates specialized cloned functions
775# partial inlining inlines only parts of functions
776KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
777endif
778
779ifneq ($(CONFIG_FRAME_WARN),0)
780KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
781endif
782
783stackp-flags-y                                    := -fno-stack-protector
784stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
785stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
786
787KBUILD_CFLAGS += $(stackp-flags-y)
788
789KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
790KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
791
792ifdef CONFIG_CC_IS_CLANG
793KBUILD_CPPFLAGS += -Qunused-arguments
794# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
795KBUILD_CFLAGS += -Wno-gnu
796# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
797# source of a reference will be _MergedGlobals and not on of the whitelisted names.
798# See modpost pattern 2
799KBUILD_CFLAGS += -mno-global-merge
800else
801
802# gcc inanely warns about local variables called 'main'
803KBUILD_CFLAGS += -Wno-main
804endif
805
806# These warnings generated too much noise in a regular build.
807# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
808KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
809KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
810
811ifdef CONFIG_FRAME_POINTER
812KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
813else
814# Some targets (ARM with Thumb2, for example), can't be built with frame
815# pointers.  For those, we don't have FUNCTION_TRACER automatically
816# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
817# incompatible with -fomit-frame-pointer with current GCC, so we don't use
818# -fomit-frame-pointer with FUNCTION_TRACER.
819ifndef CONFIG_FUNCTION_TRACER
820KBUILD_CFLAGS	+= -fomit-frame-pointer
821endif
822endif
823
824# Initialize all stack variables with a 0xAA pattern.
825ifdef CONFIG_INIT_STACK_ALL_PATTERN
826KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
827endif
828
829# Initialize all stack variables with a zero value.
830ifdef CONFIG_INIT_STACK_ALL_ZERO
831KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
832ifdef CONFIG_CC_IS_CLANG
833# https://bugs.llvm.org/show_bug.cgi?id=45497
834KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
835endif
836endif
837
838# While VLAs have been removed, GCC produces unreachable stack probes
839# for the randomize_kstack_offset feature. Disable it for all compilers.
840KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
841
842# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
843ifdef CONFIG_ZERO_CALL_USED_REGS
844KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
845endif
846
847ifdef CONFIG_FUNCTION_TRACER
848ifdef CONFIG_FTRACE_MCOUNT_USE_CC
849  CC_FLAGS_FTRACE	+= -mrecord-mcount
850  ifdef CONFIG_HAVE_NOP_MCOUNT
851    ifeq ($(call cc-option-yn, -mnop-mcount),y)
852      CC_FLAGS_FTRACE	+= -mnop-mcount
853      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
854    endif
855  endif
856endif
857ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
858  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
859endif
860ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
861  ifdef CONFIG_HAVE_C_RECORDMCOUNT
862    BUILD_C_RECORDMCOUNT := y
863    export BUILD_C_RECORDMCOUNT
864  endif
865endif
866ifdef CONFIG_HAVE_FENTRY
867  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
868  ifeq ($(call cc-option-yn, -mfentry),y)
869    CC_FLAGS_FTRACE	+= -mfentry
870    CC_FLAGS_USING	+= -DCC_USING_FENTRY
871  endif
872endif
873export CC_FLAGS_FTRACE
874KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
875KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
876endif
877
878# We trigger additional mismatches with less inlining
879ifdef CONFIG_DEBUG_SECTION_MISMATCH
880KBUILD_CFLAGS += -fno-inline-functions-called-once
881endif
882
883ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
884KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
885LDFLAGS_vmlinux += --gc-sections
886endif
887
888ifdef CONFIG_SHADOW_CALL_STACK
889CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
890KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
891export CC_FLAGS_SCS
892endif
893
894ifdef CONFIG_LTO_CLANG
895ifdef CONFIG_LTO_CLANG_THIN
896CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
897KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
898else
899CC_FLAGS_LTO	:= -flto
900endif
901CC_FLAGS_LTO	+= -fvisibility=hidden
902
903# Limit inlining across translation units to reduce binary size
904KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
905
906# Check for frame size exceeding threshold during prolog/epilog insertion
907# when using lld < 13.0.0.
908ifneq ($(CONFIG_FRAME_WARN),0)
909ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
910KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
911endif
912endif
913endif
914
915ifdef CONFIG_LTO
916KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
917KBUILD_AFLAGS	+= -fno-lto
918export CC_FLAGS_LTO
919endif
920
921ifdef CONFIG_CFI_CLANG
922CC_FLAGS_CFI	:= -fsanitize=cfi \
923		   -fsanitize-cfi-cross-dso \
924		   -fno-sanitize-cfi-canonical-jump-tables \
925		   -fno-sanitize-trap=cfi \
926		   -fno-sanitize-blacklist
927
928ifdef CONFIG_CFI_PERMISSIVE
929CC_FLAGS_CFI	+= -fsanitize-recover=cfi
930endif
931
932# If LTO flags are filtered out, we must also filter out CFI.
933CC_FLAGS_LTO	+= $(CC_FLAGS_CFI)
934KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
935export CC_FLAGS_CFI
936endif
937
938ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
939KBUILD_CFLAGS += -falign-functions=64
940endif
941
942# arch Makefile may override CC so keep this after arch Makefile is included
943NOSTDINC_FLAGS += -nostdinc
944
945# warn about C99 declaration after statement
946KBUILD_CFLAGS += -Wdeclaration-after-statement
947
948# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
949KBUILD_CFLAGS += -Wvla
950
951# disable pointer signed / unsigned warnings in gcc 4.0
952KBUILD_CFLAGS += -Wno-pointer-sign
953
954# In order to make sure new function cast mismatches are not introduced
955# in the kernel (to avoid tripping CFI checking), the kernel should be
956# globally built with -Wcast-function-type.
957KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
958
959# disable stringop warnings in gcc 8+
960KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
961
962# We'll want to enable this eventually, but it's not going away for 5.7 at least
963KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
964
965# Another good warning that we'll want to enable eventually
966KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
967
968# Enabled with W=2, disabled by default as noisy
969ifdef CONFIG_CC_IS_GCC
970KBUILD_CFLAGS += -Wno-maybe-uninitialized
971endif
972
973ifdef CONFIG_CC_IS_GCC
974# The allocators already balk at large sizes, so silence the compiler
975# warnings for bounds checks involving those possible values. While
976# -Wno-alloc-size-larger-than would normally be used here, earlier versions
977# of gcc (<9.1) weirdly don't handle the option correctly when _other_
978# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
979# doesn't work (as it is documented to), silently resolving to "0" prior to
980# version 9.1 (and producing an error more recently). Numeric values larger
981# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
982# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
983# choice, we must perform a versioned check to disable this warning.
984# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
985KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
986endif
987
988# disable invalid "can't wrap" optimizations for signed / pointers
989KBUILD_CFLAGS	+= -fno-strict-overflow
990
991# Make sure -fstack-check isn't enabled (like gentoo apparently did)
992KBUILD_CFLAGS  += -fno-stack-check
993
994# conserve stack if available
995ifdef CONFIG_CC_IS_GCC
996KBUILD_CFLAGS   += -fconserve-stack
997endif
998
999# Prohibit date/time macros, which would make the build non-deterministic
1000KBUILD_CFLAGS   += -Werror=date-time
1001
1002# enforce correct pointer usage
1003KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1004
1005# Require designated initializers for all marked structures
1006KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1007
1008# change __FILE__ to the relative path from the srctree
1009KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1010
1011# include additional Makefiles when needed
1012include-y			:= scripts/Makefile.extrawarn
1013include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1014include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1015include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1016include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1017include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1018include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1019
1020include $(addprefix $(srctree)/, $(include-y))
1021
1022# scripts/Makefile.gcc-plugins is intentionally included last.
1023# Do not add $(call cc-option,...) below this line. When you build the kernel
1024# from the clean source tree, the GCC plugins do not exist at this point.
1025
1026# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1027KBUILD_CPPFLAGS += $(KCPPFLAGS)
1028KBUILD_AFLAGS   += $(KAFLAGS)
1029KBUILD_CFLAGS   += $(KCFLAGS)
1030
1031KBUILD_LDFLAGS_MODULE += --build-id=sha1
1032LDFLAGS_vmlinux += --build-id=sha1
1033
1034ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1035LDFLAGS_vmlinux	+= $(call ld-option, -X,)
1036endif
1037
1038ifeq ($(CONFIG_RELR),y)
1039LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1040endif
1041
1042# We never want expected sections to be placed heuristically by the
1043# linker. All sections should be explicitly named in the linker script.
1044ifdef CONFIG_LD_ORPHAN_WARN
1045LDFLAGS_vmlinux += --orphan-handling=warn
1046endif
1047
1048# Align the bit size of userspace programs with the kernel
1049KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1050KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1051
1052# make the checker run with the right architecture
1053CHECKFLAGS += --arch=$(ARCH)
1054
1055# insure the checker run with the right endianness
1056CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1057
1058# the checker needs the correct machine size
1059CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1060
1061# Default kernel image to build when no specific target is given.
1062# KBUILD_IMAGE may be overruled on the command line or
1063# set in the environment
1064# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1065# this default value
1066export KBUILD_IMAGE ?= vmlinux
1067
1068#
1069# INSTALL_PATH specifies where to place the updated kernel and system map
1070# images. Default is /boot, but you can set it to other values
1071export	INSTALL_PATH ?= /boot
1072
1073#
1074# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1075# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1076# an argument if needed. Otherwise it defaults to the kernel install path
1077#
1078export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1079
1080#
1081# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1082# relocations required by build roots.  This is not defined in the
1083# makefile but the argument can be passed to make if needed.
1084#
1085
1086MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1087export MODLIB
1088
1089PHONY += prepare0
1090
1091export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1092export MODORDER := $(extmod_prefix)modules.order
1093export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1094
1095ifeq ($(KBUILD_EXTMOD),)
1096core-y			+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
1097core-$(CONFIG_BLOCK)	+= block/
1098
1099vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1100		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1101		     $(libs-y) $(libs-m)))
1102
1103vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1104		     $(patsubst %/,%,$(filter %/, $(core-) \
1105			$(drivers-) $(libs-))))
1106
1107subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1108			$(core-y) $(core-m) $(libs-y) $(libs-m) \
1109			$(drivers-y) $(drivers-m)))
1110
1111build-dirs	:= $(vmlinux-dirs)
1112clean-dirs	:= $(vmlinux-alldirs)
1113
1114# Externally visible symbols (used by link-vmlinux.sh)
1115KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1116KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1117ifdef CONFIG_MODULES
1118KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1119KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1120else
1121KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1122endif
1123KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1124
1125export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1126export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1127# used by scripts/Makefile.package
1128export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1129
1130vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1131
1132# Recurse until adjust_autoksyms.sh is satisfied
1133PHONY += autoksyms_recursive
1134ifdef CONFIG_TRIM_UNUSED_KSYMS
1135# For the kernel to actually contain only the needed exported symbols,
1136# we have to build modules as well to determine what those symbols are.
1137# (this can be evaluated only once include/config/auto.conf has been included)
1138KBUILD_MODULES := 1
1139
1140autoksyms_recursive: descend modules.order
1141	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1142	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1143endif
1144
1145autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1146
1147quiet_cmd_autoksyms_h = GEN     $@
1148      cmd_autoksyms_h = mkdir -p $(dir $@); \
1149			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1150
1151$(autoksyms_h):
1152	$(call cmd,autoksyms_h)
1153
1154ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1155
1156# Final link of vmlinux with optional arch pass after final link
1157cmd_link-vmlinux =                                                 \
1158	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1159	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1160
1161vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1162	+$(call if_changed_dep,link-vmlinux)
1163
1164targets := vmlinux
1165
1166# The actual objects are generated when descending,
1167# make sure no implicit rule kicks in
1168$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1169
1170filechk_kernel.release = \
1171	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1172
1173# Store (new) KERNELRELEASE string in include/config/kernel.release
1174include/config/kernel.release: FORCE
1175	$(call filechk,kernel.release)
1176
1177# Additional helpers built in scripts/
1178# Carefully list dependencies so we do not try to build scripts twice
1179# in parallel
1180PHONY += scripts
1181scripts: scripts_basic scripts_dtc
1182	$(Q)$(MAKE) $(build)=$(@)
1183
1184# Things we need to do before we recursively start building the kernel
1185# or the modules are listed in "prepare".
1186# A multi level approach is used. prepareN is processed before prepareN-1.
1187# archprepare is used in arch Makefiles and when processed asm symlink,
1188# version.h and scripts_basic is processed / created.
1189
1190PHONY += prepare archprepare
1191
1192archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1193	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1194	include/generated/autoconf.h remove-stale-files
1195
1196prepare0: archprepare
1197	$(Q)$(MAKE) $(build)=scripts/mod
1198	$(Q)$(MAKE) $(build)=.
1199
1200# All the preparing..
1201prepare: prepare0
1202
1203PHONY += remove-stale-files
1204remove-stale-files:
1205	$(Q)$(srctree)/scripts/remove-stale-files
1206
1207# Support for using generic headers in asm-generic
1208asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1209
1210PHONY += asm-generic uapi-asm-generic
1211asm-generic: uapi-asm-generic
1212	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1213	generic=include/asm-generic
1214uapi-asm-generic:
1215	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1216	generic=include/uapi/asm-generic
1217
1218# Generate some files
1219# ---------------------------------------------------------------------------
1220
1221# KERNELRELEASE can change from a few different places, meaning version.h
1222# needs to be updated, so this check is forced on all builds
1223
1224uts_len := 64
1225define filechk_utsrelease.h
1226	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1227	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1228	  exit 1;                                                         \
1229	fi;                                                               \
1230	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1231endef
1232
1233define filechk_version.h
1234	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1235		echo \#define LINUX_VERSION_CODE $(shell                 \
1236		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1237	else                                                             \
1238		echo \#define LINUX_VERSION_CODE $(shell                 \
1239		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1240	fi;                                                              \
1241	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1242	((c) > 255 ? 255 : (c)))';                                       \
1243	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1244	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1245	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1246endef
1247
1248$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1249$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1250$(version_h): FORCE
1251	$(call filechk,version.h)
1252
1253include/generated/utsrelease.h: include/config/kernel.release FORCE
1254	$(call filechk,utsrelease.h)
1255
1256PHONY += headerdep
1257headerdep:
1258	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1259	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1260
1261# ---------------------------------------------------------------------------
1262# Kernel headers
1263
1264#Default location for installed headers
1265export INSTALL_HDR_PATH = $(objtree)/usr
1266
1267quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1268      cmd_headers_install = \
1269	mkdir -p $(INSTALL_HDR_PATH); \
1270	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1271	usr/include $(INSTALL_HDR_PATH)
1272
1273PHONY += headers_install
1274headers_install: headers
1275	$(call cmd,headers_install)
1276
1277PHONY += archheaders archscripts
1278
1279hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1280
1281PHONY += headers
1282headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1283	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1284	  $(error Headers not exportable for the $(SRCARCH) architecture))
1285	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1286	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1287
1288ifdef CONFIG_HEADERS_INSTALL
1289prepare: headers
1290endif
1291
1292PHONY += scripts_unifdef
1293scripts_unifdef: scripts_basic
1294	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1295
1296# ---------------------------------------------------------------------------
1297# Install
1298
1299# Many distributions have the custom install script, /sbin/installkernel.
1300# If DKMS is installed, 'make install' will eventually recuses back
1301# to the this Makefile to build and install external modules.
1302# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1303
1304install: sub_make_done :=
1305
1306# ---------------------------------------------------------------------------
1307# Tools
1308
1309ifdef CONFIG_STACK_VALIDATION
1310prepare: tools/objtool
1311endif
1312
1313ifdef CONFIG_BPF
1314ifdef CONFIG_DEBUG_INFO_BTF
1315prepare: tools/bpf/resolve_btfids
1316endif
1317endif
1318
1319PHONY += resolve_btfids_clean
1320
1321resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1322
1323# tools/bpf/resolve_btfids directory might not exist
1324# in output directory, skip its clean in that case
1325resolve_btfids_clean:
1326ifneq ($(wildcard $(resolve_btfids_O)),)
1327	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1328endif
1329
1330# Clear a bunch of variables before executing the submake
1331ifeq ($(quiet),silent_)
1332tools_silent=s
1333endif
1334
1335tools/: FORCE
1336	$(Q)mkdir -p $(objtree)/tools
1337	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1338
1339tools/%: FORCE
1340	$(Q)mkdir -p $(objtree)/tools
1341	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1342
1343# ---------------------------------------------------------------------------
1344# Kernel selftest
1345
1346PHONY += kselftest
1347kselftest:
1348	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1349
1350kselftest-%: FORCE
1351	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1352
1353PHONY += kselftest-merge
1354kselftest-merge:
1355	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1356	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1357		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1358	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1359
1360# ---------------------------------------------------------------------------
1361# Devicetree files
1362
1363ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1364dtstree := arch/$(SRCARCH)/boot/dts
1365endif
1366
1367ifneq ($(dtstree),)
1368
1369%.dtb: include/config/kernel.release scripts_dtc
1370	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1371
1372%.dtbo: include/config/kernel.release scripts_dtc
1373	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1374
1375PHONY += dtbs dtbs_install dtbs_check
1376dtbs: include/config/kernel.release scripts_dtc
1377	$(Q)$(MAKE) $(build)=$(dtstree)
1378
1379ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1380export CHECK_DTBS=y
1381dtbs: dt_binding_check
1382endif
1383
1384dtbs_check: dtbs
1385
1386dtbs_install:
1387	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1388
1389ifdef CONFIG_OF_EARLY_FLATTREE
1390all: dtbs
1391endif
1392
1393endif
1394
1395PHONY += scripts_dtc
1396scripts_dtc: scripts_basic
1397	$(Q)$(MAKE) $(build)=scripts/dtc
1398
1399ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1400export CHECK_DT_BINDING=y
1401endif
1402
1403PHONY += dt_binding_check
1404dt_binding_check: scripts_dtc
1405	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1406
1407# ---------------------------------------------------------------------------
1408# Modules
1409
1410ifdef CONFIG_MODULES
1411
1412# By default, build modules as well
1413
1414all: modules
1415
1416# When we're building modules with modversions, we need to consider
1417# the built-in objects during the descend as well, in order to
1418# make sure the checksums are up to date before we record them.
1419ifdef CONFIG_MODVERSIONS
1420  KBUILD_BUILTIN := 1
1421endif
1422
1423# Build modules
1424#
1425# A module can be listed more than once in obj-m resulting in
1426# duplicate lines in modules.order files.  Those are removed
1427# using awk while concatenating to the final file.
1428
1429PHONY += modules
1430modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1431
1432cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1433
1434modules.order: $(subdir-modorder) FORCE
1435	$(call if_changed,modules_order)
1436
1437targets += modules.order
1438
1439# Target to prepare building external modules
1440PHONY += modules_prepare
1441modules_prepare: prepare
1442	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1443
1444export modules_sign_only :=
1445
1446ifeq ($(CONFIG_MODULE_SIG),y)
1447PHONY += modules_sign
1448modules_sign: modules_install
1449	@:
1450
1451# modules_sign is a subset of modules_install.
1452# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1453ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1454modules_sign_only := y
1455endif
1456endif
1457
1458modinst_pre :=
1459ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1460modinst_pre := __modinst_pre
1461endif
1462
1463modules_install: $(modinst_pre)
1464PHONY += __modinst_pre
1465__modinst_pre:
1466	@rm -rf $(MODLIB)/kernel
1467	@rm -f $(MODLIB)/source
1468	@mkdir -p $(MODLIB)/kernel
1469	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1470	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1471		rm -f $(MODLIB)/build ; \
1472		ln -s $(CURDIR) $(MODLIB)/build ; \
1473	fi
1474	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1475	@cp -f modules.builtin $(MODLIB)/
1476	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1477
1478endif # CONFIG_MODULES
1479
1480###
1481# Cleaning is done on three levels.
1482# make clean     Delete most generated files
1483#                Leave enough to build external modules
1484# make mrproper  Delete the current configuration, and all generated files
1485# make distclean Remove editor backup files, patch leftover files and the like
1486
1487# Directories & files removed with 'make clean'
1488CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1489	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1490	       compile_commands.json .thinlto-cache
1491
1492# Directories & files removed with 'make mrproper'
1493MRPROPER_FILES += include/config include/generated          \
1494		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1495		  debian snap tar-install \
1496		  .config .config.old .version \
1497		  Module.symvers \
1498		  certs/signing_key.pem \
1499		  certs/x509.genkey \
1500		  vmlinux-gdb.py \
1501		  *.spec
1502
1503# clean - Delete most, but leave enough to build external modules
1504#
1505clean: rm-files := $(CLEAN_FILES)
1506
1507PHONY += archclean vmlinuxclean
1508
1509vmlinuxclean:
1510	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1511	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1512
1513clean: archclean vmlinuxclean resolve_btfids_clean
1514
1515# mrproper - Delete all generated files, including .config
1516#
1517mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1518mrproper-dirs      := $(addprefix _mrproper_,scripts)
1519
1520PHONY += $(mrproper-dirs) mrproper
1521$(mrproper-dirs):
1522	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1523
1524mrproper: clean $(mrproper-dirs)
1525	$(call cmd,rmfiles)
1526
1527# distclean
1528#
1529PHONY += distclean
1530
1531distclean: mrproper
1532	@find . $(RCS_FIND_IGNORE) \
1533		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1534		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1535		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1536		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1537		-type f -print | xargs rm -f
1538
1539
1540# Packaging of the kernel to various formats
1541# ---------------------------------------------------------------------------
1542
1543%src-pkg: FORCE
1544	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1545%pkg: include/config/kernel.release FORCE
1546	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1547
1548# Brief documentation of the typical targets used
1549# ---------------------------------------------------------------------------
1550
1551boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1552boards := $(sort $(notdir $(boards)))
1553board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1554board-dirs := $(sort $(notdir $(board-dirs:/=)))
1555
1556PHONY += help
1557help:
1558	@echo  'Cleaning targets:'
1559	@echo  '  clean		  - Remove most generated files but keep the config and'
1560	@echo  '                    enough build support to build external modules'
1561	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1562	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1563	@echo  ''
1564	@echo  'Configuration targets:'
1565	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1566	@echo  ''
1567	@echo  'Other generic targets:'
1568	@echo  '  all		  - Build all targets marked with [*]'
1569	@echo  '* vmlinux	  - Build the bare kernel'
1570	@echo  '* modules	  - Build all modules'
1571	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1572	@echo  '  dir/            - Build all files in dir and below'
1573	@echo  '  dir/file.[ois]  - Build specified target only'
1574	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1575	@echo  '                    (requires compiler support for LLVM assembly generation)'
1576	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1577	@echo  '                    (requires a recent binutils and recent build (System.map))'
1578	@echo  '  dir/file.ko     - Build module including final link'
1579	@echo  '  modules_prepare - Set up for building external modules'
1580	@echo  '  tags/TAGS	  - Generate tags file for editors'
1581	@echo  '  cscope	  - Generate cscope index'
1582	@echo  '  gtags           - Generate GNU GLOBAL index'
1583	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1584	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1585	@echo  '  image_name	  - Output the image name (use with make -s)'
1586	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1587	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1588	 echo  ''
1589	@echo  'Static analysers:'
1590	@echo  '  checkstack      - Generate a list of stack hogs'
1591	@echo  '  versioncheck    - Sanity check on version.h usage'
1592	@echo  '  includecheck    - Check for duplicate included header files'
1593	@echo  '  export_report   - List the usages of all exported symbols'
1594	@echo  '  headerdep       - Detect inclusion cycles in headers'
1595	@echo  '  coccicheck      - Check with Coccinelle'
1596	@echo  '  clang-analyzer  - Check with clang static analyzer'
1597	@echo  '  clang-tidy      - Check with clang-tidy'
1598	@echo  ''
1599	@echo  'Tools:'
1600	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1601	@echo  ''
1602	@echo  'Kernel selftest:'
1603	@echo  '  kselftest         - Build and run kernel selftest'
1604	@echo  '                      Build, install, and boot kernel before'
1605	@echo  '                      running kselftest on it'
1606	@echo  '                      Run as root for full coverage'
1607	@echo  '  kselftest-all     - Build kernel selftest'
1608	@echo  '  kselftest-install - Build and install kernel selftest'
1609	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1610	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1611	@echo  '		      kselftest to existing .config.'
1612	@echo  ''
1613	@$(if $(dtstree), \
1614		echo 'Devicetree:'; \
1615		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1616		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1617		echo '  dt_binding_check - Validate device tree binding documents'; \
1618		echo '  dtbs_check       - Validate device tree source files';\
1619		echo '')
1620
1621	@echo 'Userspace tools targets:'
1622	@echo '  use "make tools/help"'
1623	@echo '  or  "cd tools; make help"'
1624	@echo  ''
1625	@echo  'Kernel packaging:'
1626	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1627	@echo  ''
1628	@echo  'Documentation targets:'
1629	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1630	@echo  ''
1631	@echo  'Architecture specific targets ($(SRCARCH)):'
1632	@$(or $(archhelp),\
1633		echo '  No architecture specific help defined for $(SRCARCH)')
1634	@echo  ''
1635	@$(if $(boards), \
1636		$(foreach b, $(boards), \
1637		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1638		echo '')
1639	@$(if $(board-dirs), \
1640		$(foreach b, $(board-dirs), \
1641		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1642		printf "  %-16s - Show all of the above\\n" help-boards; \
1643		echo '')
1644
1645	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1646	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1647	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1648	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1649	@echo  '                       (sparse by default)'
1650	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1651	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1652	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1653	@echo  '		1: warnings which may be relevant and do not occur too often'
1654	@echo  '		2: warnings which occur quite often but may still be relevant'
1655	@echo  '		3: more obscure warnings, can most likely be ignored'
1656	@echo  '		Multiple levels can be combined with W=12 or W=123'
1657	@echo  ''
1658	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1659	@echo  'For further info see the ./README file'
1660
1661
1662help-board-dirs := $(addprefix help-,$(board-dirs))
1663
1664help-boards: $(help-board-dirs)
1665
1666boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1667
1668$(help-board-dirs): help-%:
1669	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1670	@$(if $(boards-per-dir), \
1671		$(foreach b, $(boards-per-dir), \
1672		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1673		echo '')
1674
1675
1676# Documentation targets
1677# ---------------------------------------------------------------------------
1678DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1679	       linkcheckdocs dochelp refcheckdocs
1680PHONY += $(DOC_TARGETS)
1681$(DOC_TARGETS):
1682	$(Q)$(MAKE) $(build)=Documentation $@
1683
1684# Misc
1685# ---------------------------------------------------------------------------
1686
1687PHONY += scripts_gdb
1688scripts_gdb: prepare0
1689	$(Q)$(MAKE) $(build)=scripts/gdb
1690	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1691
1692ifdef CONFIG_GDB_SCRIPTS
1693all: scripts_gdb
1694endif
1695
1696else # KBUILD_EXTMOD
1697
1698###
1699# External module support.
1700# When building external modules the kernel used as basis is considered
1701# read-only, and no consistency checks are made and the make
1702# system is not used on the basis kernel. If updates are required
1703# in the basis kernel ordinary make commands (without M=...) must be used.
1704
1705# We are always building only modules.
1706KBUILD_BUILTIN :=
1707KBUILD_MODULES := 1
1708
1709build-dirs := $(KBUILD_EXTMOD)
1710$(MODORDER): descend
1711	@:
1712
1713compile_commands.json: $(extmod_prefix)compile_commands.json
1714PHONY += compile_commands.json
1715
1716clean-dirs := $(KBUILD_EXTMOD)
1717clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1718	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1719
1720PHONY += prepare
1721# now expand this into a simple variable to reduce the cost of shell evaluations
1722prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1723prepare:
1724	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1725		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1726		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1727		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1728	fi
1729
1730PHONY += help
1731help:
1732	@echo  '  Building external modules.'
1733	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1734	@echo  ''
1735	@echo  '  modules         - default target, build the module(s)'
1736	@echo  '  modules_install - install the module'
1737	@echo  '  clean           - remove generated files in module directory only'
1738	@echo  ''
1739
1740# no-op for external module builds
1741PHONY += modules_prepare
1742
1743endif # KBUILD_EXTMOD
1744
1745# ---------------------------------------------------------------------------
1746# Modules
1747
1748PHONY += modules modules_install
1749
1750ifdef CONFIG_MODULES
1751
1752modules: modules_check
1753	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1754
1755PHONY += modules_check
1756modules_check: $(MODORDER)
1757	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1758
1759quiet_cmd_depmod = DEPMOD  $(MODLIB)
1760      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1761                   $(KERNELRELEASE)
1762
1763modules_install:
1764	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1765	$(call cmd,depmod)
1766
1767else # CONFIG_MODULES
1768
1769# Modules not configured
1770# ---------------------------------------------------------------------------
1771
1772modules modules_install:
1773	@echo >&2 '***'
1774	@echo >&2 '*** The present kernel configuration has modules disabled.'
1775	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1776	@echo >&2 '*** to enable CONFIG_MODULES.'
1777	@echo >&2 '***'
1778	@exit 1
1779
1780endif # CONFIG_MODULES
1781
1782# Single targets
1783# ---------------------------------------------------------------------------
1784# To build individual files in subdirectories, you can do like this:
1785#
1786#   make foo/bar/baz.s
1787#
1788# The supported suffixes for single-target are listed in 'single-targets'
1789#
1790# To build only under specific subdirectories, you can do like this:
1791#
1792#   make foo/bar/baz/
1793
1794ifdef single-build
1795
1796# .ko is special because modpost is needed
1797single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1798single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1799
1800$(single-ko): single_modpost
1801	@:
1802$(single-no-ko): descend
1803	@:
1804
1805ifeq ($(KBUILD_EXTMOD),)
1806# For the single build of in-tree modules, use a temporary file to avoid
1807# the situation of modules_install installing an invalid modules.order.
1808MODORDER := .modules.tmp
1809endif
1810
1811PHONY += single_modpost
1812single_modpost: $(single-no-ko) modules_prepare
1813	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1814	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1815
1816KBUILD_MODULES := 1
1817
1818export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1819
1820# trim unrelated directories
1821build-dirs := $(foreach d, $(build-dirs), \
1822			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1823
1824endif
1825
1826ifndef CONFIG_MODULES
1827KBUILD_MODULES :=
1828endif
1829
1830# Handle descending into subdirectories listed in $(build-dirs)
1831# Preset locale variables to speed up the build process. Limit locale
1832# tweaks to this spot to avoid wrong language settings when running
1833# make menuconfig etc.
1834# Error messages still appears in the original language
1835PHONY += descend $(build-dirs)
1836descend: $(build-dirs)
1837$(build-dirs): prepare
1838	$(Q)$(MAKE) $(build)=$@ \
1839	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1840	need-builtin=1 need-modorder=1
1841
1842clean-dirs := $(addprefix _clean_, $(clean-dirs))
1843PHONY += $(clean-dirs) clean
1844$(clean-dirs):
1845	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1846
1847clean: $(clean-dirs)
1848	$(call cmd,rmfiles)
1849	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1850		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1851		-o -name '*.ko.*' \
1852		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1853		-o -name '*.dwo' -o -name '*.lst' \
1854		-o -name '*.su' -o -name '*.mod' \
1855		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1856		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1857		-o -name '*.asn1.[ch]' \
1858		-o -name '*.symtypes' -o -name 'modules.order' \
1859		-o -name '.tmp_*.o.*' \
1860		-o -name '*.c.[012]*.*' \
1861		-o -name '*.ll' \
1862		-o -name '*.gcno' \
1863		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
1864
1865# Generate tags for editors
1866# ---------------------------------------------------------------------------
1867quiet_cmd_tags = GEN     $@
1868      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1869
1870tags TAGS cscope gtags: FORCE
1871	$(call cmd,tags)
1872
1873# Script to generate missing namespace dependencies
1874# ---------------------------------------------------------------------------
1875
1876PHONY += nsdeps
1877nsdeps: export KBUILD_NSDEPS=1
1878nsdeps: modules
1879	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1880
1881# Clang Tooling
1882# ---------------------------------------------------------------------------
1883
1884quiet_cmd_gen_compile_commands = GEN     $@
1885      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1886
1887$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1888	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1889	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1890	$(call if_changed,gen_compile_commands)
1891
1892targets += $(extmod_prefix)compile_commands.json
1893
1894PHONY += clang-tidy clang-analyzer
1895
1896ifdef CONFIG_CC_IS_CLANG
1897quiet_cmd_clang_tools = CHECK   $<
1898      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1899
1900clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1901	$(call cmd,clang_tools)
1902else
1903clang-tidy clang-analyzer:
1904	@echo "$@ requires CC=clang" >&2
1905	@false
1906endif
1907
1908# Scripts to check various things for consistency
1909# ---------------------------------------------------------------------------
1910
1911PHONY += includecheck versioncheck coccicheck export_report
1912
1913includecheck:
1914	find $(srctree)/* $(RCS_FIND_IGNORE) \
1915		-name '*.[hcS]' -type f -print | sort \
1916		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1917
1918versioncheck:
1919	find $(srctree)/* $(RCS_FIND_IGNORE) \
1920		-name '*.[hcS]' -type f -print | sort \
1921		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1922
1923coccicheck:
1924	$(Q)$(BASH) $(srctree)/scripts/$@
1925
1926export_report:
1927	$(PERL) $(srctree)/scripts/export_report.pl
1928
1929PHONY += checkstack kernelrelease kernelversion image_name
1930
1931# UML needs a little special treatment here.  It wants to use the host
1932# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1933# else wants $(ARCH), including people doing cross-builds, which means
1934# that $(SUBARCH) doesn't work here.
1935ifeq ($(ARCH), um)
1936CHECKSTACK_ARCH := $(SUBARCH)
1937else
1938CHECKSTACK_ARCH := $(ARCH)
1939endif
1940checkstack:
1941	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1942	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1943
1944kernelrelease:
1945	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1946
1947kernelversion:
1948	@echo $(KERNELVERSION)
1949
1950image_name:
1951	@echo $(KBUILD_IMAGE)
1952
1953quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1954      cmd_rmfiles = rm -rf $(rm-files)
1955
1956# read saved command lines for existing targets
1957existing-targets := $(wildcard $(sort $(targets)))
1958
1959-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1960
1961endif # config-build
1962endif # mixed-build
1963endif # need-sub-make
1964
1965PHONY += FORCE
1966FORCE:
1967
1968# Declare the contents of the PHONY variable as phony.  We keep that
1969# information in a variable so we can use it in if_changed and friends.
1970.PHONY: $(PHONY)
1971