xref: /openbmc/linux/Makefile (revision fc93a4cd)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 18
4SUBLEVEL = 0
5EXTRAVERSION = -rc1
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
439HOSTPKG_CONFIG	= pkg-config
440
441KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
442			 -O2 -fomit-frame-pointer -std=gnu11 \
443			 -Wdeclaration-after-statement
444KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
445KBUILD_USERLDFLAGS := $(USERLDFLAGS)
446
447KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
448KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
449KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
450KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
451
452# Make variables (CC, etc...)
453CPP		= $(CC) -E
454ifneq ($(LLVM),)
455CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
456LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
457AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
458NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
459OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
460OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
461READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
462STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
463else
464CC		= $(CROSS_COMPILE)gcc
465LD		= $(CROSS_COMPILE)ld
466AR		= $(CROSS_COMPILE)ar
467NM		= $(CROSS_COMPILE)nm
468OBJCOPY		= $(CROSS_COMPILE)objcopy
469OBJDUMP		= $(CROSS_COMPILE)objdump
470READELF		= $(CROSS_COMPILE)readelf
471STRIP		= $(CROSS_COMPILE)strip
472endif
473PAHOLE		= pahole
474RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
475LEX		= flex
476YACC		= bison
477AWK		= awk
478INSTALLKERNEL  := installkernel
479DEPMOD		= depmod
480PERL		= perl
481PYTHON3		= python3
482CHECK		= sparse
483BASH		= bash
484KGZIP		= gzip
485KBZIP2		= bzip2
486KLZOP		= lzop
487LZMA		= lzma
488LZ4		= lz4c
489XZ		= xz
490ZSTD		= zstd
491
492PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
493
494CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
495		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
496NOSTDINC_FLAGS :=
497CFLAGS_MODULE   =
498AFLAGS_MODULE   =
499LDFLAGS_MODULE  =
500CFLAGS_KERNEL	=
501AFLAGS_KERNEL	=
502LDFLAGS_vmlinux =
503
504# Use USERINCLUDE when you must reference the UAPI directories only.
505USERINCLUDE    := \
506		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
507		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
508		-I$(srctree)/include/uapi \
509		-I$(objtree)/include/generated/uapi \
510                -include $(srctree)/include/linux/compiler-version.h \
511                -include $(srctree)/include/linux/kconfig.h
512
513# Use LINUXINCLUDE when you must reference the include/ directory.
514# Needed to be compatible with the O= option
515LINUXINCLUDE    := \
516		-I$(srctree)/arch/$(SRCARCH)/include \
517		-I$(objtree)/arch/$(SRCARCH)/include/generated \
518		$(if $(building_out_of_srctree),-I$(srctree)/include) \
519		-I$(objtree)/include \
520		$(USERINCLUDE)
521
522KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
523KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
524		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
525		   -Werror=implicit-function-declaration -Werror=implicit-int \
526		   -Werror=return-type -Wno-format-security \
527		   -std=gnu11
528KBUILD_CPPFLAGS := -D__KERNEL__
529KBUILD_AFLAGS_KERNEL :=
530KBUILD_CFLAGS_KERNEL :=
531KBUILD_AFLAGS_MODULE  := -DMODULE
532KBUILD_CFLAGS_MODULE  := -DMODULE
533KBUILD_LDFLAGS_MODULE :=
534KBUILD_LDFLAGS :=
535CLANG_FLAGS :=
536
537export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
538export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
539export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
540export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
541export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
542export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
543
544export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
545export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
546export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
547export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
548export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
549export PAHOLE_FLAGS
550
551# Files to ignore in find ... statements
552
553export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
554			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
555			  -prune -o
556export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
557			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
558
559# ===========================================================================
560# Rules shared between *config targets and build targets
561
562# Basic helpers built in scripts/basic/
563PHONY += scripts_basic
564scripts_basic:
565	$(Q)$(MAKE) $(build)=scripts/basic
566
567PHONY += outputmakefile
568ifdef building_out_of_srctree
569# Before starting out-of-tree build, make sure the source tree is clean.
570# outputmakefile generates a Makefile in the output directory, if using a
571# separate output directory. This allows convenient use of make in the
572# output directory.
573# At the same time when output Makefile generated, generate .gitignore to
574# ignore whole output directory
575
576quiet_cmd_makefile = GEN     Makefile
577      cmd_makefile = { \
578	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
579	echo "include $(srctree)/Makefile"; \
580	} > Makefile
581
582outputmakefile:
583	$(Q)if [ -f $(srctree)/.config -o \
584		 -d $(srctree)/include/config -o \
585		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
586		echo >&2 "***"; \
587		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
588		echo >&2 "*** in $(abs_srctree)";\
589		echo >&2 "***"; \
590		false; \
591	fi
592	$(Q)ln -fsn $(srctree) source
593	$(call cmd,makefile)
594	$(Q)test -e .gitignore || \
595	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
596endif
597
598# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
599# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
600# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
601# and from include/config/auto.conf.cmd to detect the compiler upgrade.
602CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
603
604ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
605include $(srctree)/scripts/Makefile.clang
606endif
607
608# Include this also for config targets because some architectures need
609# cc-cross-prefix to determine CROSS_COMPILE.
610ifdef need-compiler
611include $(srctree)/scripts/Makefile.compiler
612endif
613
614ifdef config-build
615# ===========================================================================
616# *config targets only - make sure prerequisites are updated, and descend
617# in scripts/kconfig to make the *config target
618
619# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
620# KBUILD_DEFCONFIG may point out an alternative default configuration
621# used for 'make defconfig'
622include $(srctree)/arch/$(SRCARCH)/Makefile
623export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
624
625config: outputmakefile scripts_basic FORCE
626	$(Q)$(MAKE) $(build)=scripts/kconfig $@
627
628%config: outputmakefile scripts_basic FORCE
629	$(Q)$(MAKE) $(build)=scripts/kconfig $@
630
631else #!config-build
632# ===========================================================================
633# Build targets only - this includes vmlinux, arch specific targets, clean
634# targets and others. In general all targets except *config targets.
635
636# If building an external module we do not care about the all: rule
637# but instead __all depend on modules
638PHONY += all
639ifeq ($(KBUILD_EXTMOD),)
640__all: all
641else
642__all: modules
643endif
644
645# Decide whether to build built-in, modular, or both.
646# Normally, just do built-in.
647
648KBUILD_MODULES :=
649KBUILD_BUILTIN := 1
650
651# If we have only "make modules", don't compile built-in objects.
652ifeq ($(MAKECMDGOALS),modules)
653  KBUILD_BUILTIN :=
654endif
655
656# If we have "make <whatever> modules", compile modules
657# in addition to whatever we do anyway.
658# Just "make" or "make all" shall build modules as well
659
660ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
661  KBUILD_MODULES := 1
662endif
663
664ifeq ($(MAKECMDGOALS),)
665  KBUILD_MODULES := 1
666endif
667
668export KBUILD_MODULES KBUILD_BUILTIN
669
670ifdef need-config
671include include/config/auto.conf
672endif
673
674ifeq ($(KBUILD_EXTMOD),)
675# Objects we will link into vmlinux / subdirs we need to visit
676core-y		:= init/ usr/ arch/$(SRCARCH)/
677drivers-y	:= drivers/ sound/
678drivers-$(CONFIG_SAMPLES) += samples/
679drivers-$(CONFIG_NET) += net/
680drivers-y	+= virt/
681libs-y		:= lib/
682endif # KBUILD_EXTMOD
683
684# The all: target is the default when no target is given on the
685# command line.
686# This allow a user to issue only 'make' to build a kernel including modules
687# Defaults to vmlinux, but the arch makefile usually adds further targets
688all: vmlinux
689
690CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
691ifdef CONFIG_CC_IS_GCC
692CFLAGS_GCOV	+= -fno-tree-loop-im
693endif
694export CFLAGS_GCOV
695
696# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
697ifdef CONFIG_FUNCTION_TRACER
698  CC_FLAGS_FTRACE := -pg
699endif
700
701include $(srctree)/arch/$(SRCARCH)/Makefile
702
703ifdef need-config
704ifdef may-sync-config
705# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
706# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
707# because some architectures define CROSS_COMPILE there.
708include include/config/auto.conf.cmd
709
710$(KCONFIG_CONFIG):
711	@echo >&2 '***'
712	@echo >&2 '*** Configuration file "$@" not found!'
713	@echo >&2 '***'
714	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
715	@echo >&2 '*** "make menuconfig" or "make xconfig").'
716	@echo >&2 '***'
717	@/bin/false
718
719# The actual configuration files used during the build are stored in
720# include/generated/ and include/config/. Update them if .config is newer than
721# include/config/auto.conf (which mirrors .config).
722#
723# This exploits the 'multi-target pattern rule' trick.
724# The syncconfig should be executed only once to make all the targets.
725# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
726#
727# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
728# so you cannot notice that Kconfig is waiting for the user input.
729%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
730	$(Q)$(kecho) "  SYNC    $@"
731	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
732else # !may-sync-config
733# External modules and some install targets need include/generated/autoconf.h
734# and include/config/auto.conf but do not care if they are up-to-date.
735# Use auto.conf to trigger the test
736PHONY += include/config/auto.conf
737
738include/config/auto.conf:
739	$(Q)test -e include/generated/autoconf.h -a -e $@ || (		\
740	echo >&2;							\
741	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
742	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
743	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
744	echo >&2 ;							\
745	/bin/false)
746
747endif # may-sync-config
748endif # need-config
749
750KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
751KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
752KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
753KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
754KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
755
756ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
757KBUILD_CFLAGS += -O2
758else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
759KBUILD_CFLAGS += -O3
760else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
761KBUILD_CFLAGS += -Os
762endif
763
764# Tell gcc to never replace conditional load with a non-conditional one
765ifdef CONFIG_CC_IS_GCC
766# gcc-10 renamed --param=allow-store-data-races=0 to
767# -fno-allow-store-data-races.
768KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
769KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
770endif
771
772ifdef CONFIG_READABLE_ASM
773# Disable optimizations that make assembler listings hard to read.
774# reorder blocks reorders the control in the function
775# ipa clone creates specialized cloned functions
776# partial inlining inlines only parts of functions
777KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
778endif
779
780ifneq ($(CONFIG_FRAME_WARN),0)
781KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
782endif
783
784stackp-flags-y                                    := -fno-stack-protector
785stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
786stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
787
788KBUILD_CFLAGS += $(stackp-flags-y)
789
790KBUILD_CFLAGS-$(CONFIG_WERROR) += -Werror
791KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
792
793ifdef CONFIG_CC_IS_CLANG
794KBUILD_CPPFLAGS += -Qunused-arguments
795# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
796KBUILD_CFLAGS += -Wno-gnu
797else
798
799# gcc inanely warns about local variables called 'main'
800KBUILD_CFLAGS += -Wno-main
801endif
802
803# These warnings generated too much noise in a regular build.
804# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
805KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
806KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
807
808ifdef CONFIG_FRAME_POINTER
809KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
810else
811# Some targets (ARM with Thumb2, for example), can't be built with frame
812# pointers.  For those, we don't have FUNCTION_TRACER automatically
813# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
814# incompatible with -fomit-frame-pointer with current GCC, so we don't use
815# -fomit-frame-pointer with FUNCTION_TRACER.
816ifndef CONFIG_FUNCTION_TRACER
817KBUILD_CFLAGS	+= -fomit-frame-pointer
818endif
819endif
820
821# Initialize all stack variables with a 0xAA pattern.
822ifdef CONFIG_INIT_STACK_ALL_PATTERN
823KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
824endif
825
826# Initialize all stack variables with a zero value.
827ifdef CONFIG_INIT_STACK_ALL_ZERO
828KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
829ifdef CONFIG_CC_IS_CLANG
830# https://bugs.llvm.org/show_bug.cgi?id=45497
831KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
832endif
833endif
834
835# While VLAs have been removed, GCC produces unreachable stack probes
836# for the randomize_kstack_offset feature. Disable it for all compilers.
837KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
838
839# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
840ifdef CONFIG_ZERO_CALL_USED_REGS
841KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
842endif
843
844ifdef CONFIG_FUNCTION_TRACER
845ifdef CONFIG_FTRACE_MCOUNT_USE_CC
846  CC_FLAGS_FTRACE	+= -mrecord-mcount
847  ifdef CONFIG_HAVE_NOP_MCOUNT
848    ifeq ($(call cc-option-yn, -mnop-mcount),y)
849      CC_FLAGS_FTRACE	+= -mnop-mcount
850      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
851    endif
852  endif
853endif
854ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
855  CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
856endif
857ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
858  ifdef CONFIG_HAVE_C_RECORDMCOUNT
859    BUILD_C_RECORDMCOUNT := y
860    export BUILD_C_RECORDMCOUNT
861  endif
862endif
863ifdef CONFIG_HAVE_FENTRY
864  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
865  ifeq ($(call cc-option-yn, -mfentry),y)
866    CC_FLAGS_FTRACE	+= -mfentry
867    CC_FLAGS_USING	+= -DCC_USING_FENTRY
868  endif
869endif
870export CC_FLAGS_FTRACE
871KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
872KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
873endif
874
875# We trigger additional mismatches with less inlining
876ifdef CONFIG_DEBUG_SECTION_MISMATCH
877KBUILD_CFLAGS += -fno-inline-functions-called-once
878endif
879
880ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
881KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
882LDFLAGS_vmlinux += --gc-sections
883endif
884
885ifdef CONFIG_SHADOW_CALL_STACK
886CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
887KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
888export CC_FLAGS_SCS
889endif
890
891ifdef CONFIG_LTO_CLANG
892ifdef CONFIG_LTO_CLANG_THIN
893CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
894KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
895else
896CC_FLAGS_LTO	:= -flto
897endif
898CC_FLAGS_LTO	+= -fvisibility=hidden
899
900# Limit inlining across translation units to reduce binary size
901KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
902
903# Check for frame size exceeding threshold during prolog/epilog insertion
904# when using lld < 13.0.0.
905ifneq ($(CONFIG_FRAME_WARN),0)
906ifeq ($(shell test $(CONFIG_LLD_VERSION) -lt 130000; echo $$?),0)
907KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
908endif
909endif
910endif
911
912ifdef CONFIG_LTO
913KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
914KBUILD_AFLAGS	+= -fno-lto
915export CC_FLAGS_LTO
916endif
917
918ifdef CONFIG_CFI_CLANG
919CC_FLAGS_CFI	:= -fsanitize=cfi \
920		   -fsanitize-cfi-cross-dso \
921		   -fno-sanitize-cfi-canonical-jump-tables \
922		   -fno-sanitize-trap=cfi \
923		   -fno-sanitize-blacklist
924
925ifdef CONFIG_CFI_PERMISSIVE
926CC_FLAGS_CFI	+= -fsanitize-recover=cfi
927endif
928
929# If LTO flags are filtered out, we must also filter out CFI.
930CC_FLAGS_LTO	+= $(CC_FLAGS_CFI)
931KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
932export CC_FLAGS_CFI
933endif
934
935ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B
936KBUILD_CFLAGS += -falign-functions=64
937endif
938
939# arch Makefile may override CC so keep this after arch Makefile is included
940NOSTDINC_FLAGS += -nostdinc
941
942# warn about C99 declaration after statement
943KBUILD_CFLAGS += -Wdeclaration-after-statement
944
945# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
946KBUILD_CFLAGS += -Wvla
947
948# disable pointer signed / unsigned warnings in gcc 4.0
949KBUILD_CFLAGS += -Wno-pointer-sign
950
951# In order to make sure new function cast mismatches are not introduced
952# in the kernel (to avoid tripping CFI checking), the kernel should be
953# globally built with -Wcast-function-type.
954KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
955
956# disable stringop warnings in gcc 8+
957KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
958
959# We'll want to enable this eventually, but it's not going away for 5.7 at least
960KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
961
962# Another good warning that we'll want to enable eventually
963KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
964
965# Enabled with W=2, disabled by default as noisy
966ifdef CONFIG_CC_IS_GCC
967KBUILD_CFLAGS += -Wno-maybe-uninitialized
968endif
969
970ifdef CONFIG_CC_IS_GCC
971# The allocators already balk at large sizes, so silence the compiler
972# warnings for bounds checks involving those possible values. While
973# -Wno-alloc-size-larger-than would normally be used here, earlier versions
974# of gcc (<9.1) weirdly don't handle the option correctly when _other_
975# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
976# doesn't work (as it is documented to), silently resolving to "0" prior to
977# version 9.1 (and producing an error more recently). Numeric values larger
978# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
979# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
980# choice, we must perform a versioned check to disable this warning.
981# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
982KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0901, -Wno-alloc-size-larger-than)
983endif
984
985# disable invalid "can't wrap" optimizations for signed / pointers
986KBUILD_CFLAGS	+= -fno-strict-overflow
987
988# Make sure -fstack-check isn't enabled (like gentoo apparently did)
989KBUILD_CFLAGS  += -fno-stack-check
990
991# conserve stack if available
992ifdef CONFIG_CC_IS_GCC
993KBUILD_CFLAGS   += -fconserve-stack
994endif
995
996# Prohibit date/time macros, which would make the build non-deterministic
997KBUILD_CFLAGS   += -Werror=date-time
998
999# enforce correct pointer usage
1000KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1001
1002# Require designated initializers for all marked structures
1003KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1004
1005# change __FILE__ to the relative path from the srctree
1006KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1007
1008# include additional Makefiles when needed
1009include-y			:= scripts/Makefile.extrawarn
1010include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1011include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1012include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1013include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1014include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1015include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1016
1017include $(addprefix $(srctree)/, $(include-y))
1018
1019# scripts/Makefile.gcc-plugins is intentionally included last.
1020# Do not add $(call cc-option,...) below this line. When you build the kernel
1021# from the clean source tree, the GCC plugins do not exist at this point.
1022
1023# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1024KBUILD_CPPFLAGS += $(KCPPFLAGS)
1025KBUILD_AFLAGS   += $(KAFLAGS)
1026KBUILD_CFLAGS   += $(KCFLAGS)
1027
1028KBUILD_LDFLAGS_MODULE += --build-id=sha1
1029LDFLAGS_vmlinux += --build-id=sha1
1030
1031ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1032LDFLAGS_vmlinux	+= $(call ld-option, -X,)
1033endif
1034
1035ifeq ($(CONFIG_RELR),y)
1036LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1037endif
1038
1039# We never want expected sections to be placed heuristically by the
1040# linker. All sections should be explicitly named in the linker script.
1041ifdef CONFIG_LD_ORPHAN_WARN
1042LDFLAGS_vmlinux += --orphan-handling=warn
1043endif
1044
1045# Align the bit size of userspace programs with the kernel
1046KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1047KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1048
1049# make the checker run with the right architecture
1050CHECKFLAGS += --arch=$(ARCH)
1051
1052# insure the checker run with the right endianness
1053CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1054
1055# the checker needs the correct machine size
1056CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1057
1058# Default kernel image to build when no specific target is given.
1059# KBUILD_IMAGE may be overruled on the command line or
1060# set in the environment
1061# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1062# this default value
1063export KBUILD_IMAGE ?= vmlinux
1064
1065#
1066# INSTALL_PATH specifies where to place the updated kernel and system map
1067# images. Default is /boot, but you can set it to other values
1068export	INSTALL_PATH ?= /boot
1069
1070#
1071# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1072# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1073# an argument if needed. Otherwise it defaults to the kernel install path
1074#
1075export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1076
1077#
1078# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1079# relocations required by build roots.  This is not defined in the
1080# makefile but the argument can be passed to make if needed.
1081#
1082
1083MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1084export MODLIB
1085
1086PHONY += prepare0
1087
1088export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1089export MODORDER := $(extmod_prefix)modules.order
1090export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1091
1092ifeq ($(KBUILD_EXTMOD),)
1093core-y			+= kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
1094core-$(CONFIG_BLOCK)	+= block/
1095
1096vmlinux-dirs	:= $(patsubst %/,%,$(filter %/, \
1097		     $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1098		     $(libs-y) $(libs-m)))
1099
1100vmlinux-alldirs	:= $(sort $(vmlinux-dirs) Documentation \
1101		     $(patsubst %/,%,$(filter %/, $(core-) \
1102			$(drivers-) $(libs-))))
1103
1104subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1105			$(core-y) $(core-m) $(libs-y) $(libs-m) \
1106			$(drivers-y) $(drivers-m)))
1107
1108build-dirs	:= $(vmlinux-dirs)
1109clean-dirs	:= $(vmlinux-alldirs)
1110
1111# Externally visible symbols (used by link-vmlinux.sh)
1112KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1113KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1114ifdef CONFIG_MODULES
1115KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1116KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1117else
1118KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1119endif
1120KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1121
1122export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1123export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1124# used by scripts/Makefile.package
1125export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1126
1127vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1128
1129# Recurse until adjust_autoksyms.sh is satisfied
1130PHONY += autoksyms_recursive
1131ifdef CONFIG_TRIM_UNUSED_KSYMS
1132# For the kernel to actually contain only the needed exported symbols,
1133# we have to build modules as well to determine what those symbols are.
1134# (this can be evaluated only once include/config/auto.conf has been included)
1135KBUILD_MODULES := 1
1136
1137autoksyms_recursive: descend modules.order
1138	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1139	  "$(MAKE) -f $(srctree)/Makefile vmlinux"
1140endif
1141
1142autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1143
1144quiet_cmd_autoksyms_h = GEN     $@
1145      cmd_autoksyms_h = mkdir -p $(dir $@); \
1146			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1147
1148$(autoksyms_h):
1149	$(call cmd,autoksyms_h)
1150
1151ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1152
1153# Final link of vmlinux with optional arch pass after final link
1154cmd_link-vmlinux =                                                 \
1155	$(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)";    \
1156	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1157
1158vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1159	+$(call if_changed_dep,link-vmlinux)
1160
1161targets := vmlinux
1162
1163# The actual objects are generated when descending,
1164# make sure no implicit rule kicks in
1165$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1166
1167filechk_kernel.release = \
1168	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1169
1170# Store (new) KERNELRELEASE string in include/config/kernel.release
1171include/config/kernel.release: FORCE
1172	$(call filechk,kernel.release)
1173
1174# Additional helpers built in scripts/
1175# Carefully list dependencies so we do not try to build scripts twice
1176# in parallel
1177PHONY += scripts
1178scripts: scripts_basic scripts_dtc
1179	$(Q)$(MAKE) $(build)=$(@)
1180
1181# Things we need to do before we recursively start building the kernel
1182# or the modules are listed in "prepare".
1183# A multi level approach is used. prepareN is processed before prepareN-1.
1184# archprepare is used in arch Makefiles and when processed asm symlink,
1185# version.h and scripts_basic is processed / created.
1186
1187PHONY += prepare archprepare
1188
1189archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1190	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1191	include/generated/autoconf.h remove-stale-files
1192
1193prepare0: archprepare
1194	$(Q)$(MAKE) $(build)=scripts/mod
1195	$(Q)$(MAKE) $(build)=.
1196
1197# All the preparing..
1198prepare: prepare0
1199
1200PHONY += remove-stale-files
1201remove-stale-files:
1202	$(Q)$(srctree)/scripts/remove-stale-files
1203
1204# Support for using generic headers in asm-generic
1205asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1206
1207PHONY += asm-generic uapi-asm-generic
1208asm-generic: uapi-asm-generic
1209	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1210	generic=include/asm-generic
1211uapi-asm-generic:
1212	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1213	generic=include/uapi/asm-generic
1214
1215# Generate some files
1216# ---------------------------------------------------------------------------
1217
1218# KERNELRELEASE can change from a few different places, meaning version.h
1219# needs to be updated, so this check is forced on all builds
1220
1221uts_len := 64
1222define filechk_utsrelease.h
1223	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1224	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1225	  exit 1;                                                         \
1226	fi;                                                               \
1227	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1228endef
1229
1230define filechk_version.h
1231	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1232		echo \#define LINUX_VERSION_CODE $(shell                 \
1233		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1234	else                                                             \
1235		echo \#define LINUX_VERSION_CODE $(shell                 \
1236		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1237	fi;                                                              \
1238	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1239	((c) > 255 ? 255 : (c)))';                                       \
1240	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1241	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1242	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1243endef
1244
1245$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1246$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1247$(version_h): FORCE
1248	$(call filechk,version.h)
1249
1250include/generated/utsrelease.h: include/config/kernel.release FORCE
1251	$(call filechk,utsrelease.h)
1252
1253PHONY += headerdep
1254headerdep:
1255	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1256	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1257
1258# ---------------------------------------------------------------------------
1259# Kernel headers
1260
1261#Default location for installed headers
1262export INSTALL_HDR_PATH = $(objtree)/usr
1263
1264quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1265      cmd_headers_install = \
1266	mkdir -p $(INSTALL_HDR_PATH); \
1267	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1268	usr/include $(INSTALL_HDR_PATH)
1269
1270PHONY += headers_install
1271headers_install: headers
1272	$(call cmd,headers_install)
1273
1274PHONY += archheaders archscripts
1275
1276hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1277
1278PHONY += headers
1279headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1280	$(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1281	  $(error Headers not exportable for the $(SRCARCH) architecture))
1282	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1283	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1284
1285ifdef CONFIG_HEADERS_INSTALL
1286prepare: headers
1287endif
1288
1289PHONY += scripts_unifdef
1290scripts_unifdef: scripts_basic
1291	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1292
1293# ---------------------------------------------------------------------------
1294# Install
1295
1296# Many distributions have the custom install script, /sbin/installkernel.
1297# If DKMS is installed, 'make install' will eventually recuses back
1298# to the this Makefile to build and install external modules.
1299# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1300
1301install: sub_make_done :=
1302
1303# ---------------------------------------------------------------------------
1304# Tools
1305
1306ifdef CONFIG_STACK_VALIDATION
1307prepare: tools/objtool
1308endif
1309
1310ifdef CONFIG_BPF
1311ifdef CONFIG_DEBUG_INFO_BTF
1312prepare: tools/bpf/resolve_btfids
1313endif
1314endif
1315
1316PHONY += resolve_btfids_clean
1317
1318resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1319
1320# tools/bpf/resolve_btfids directory might not exist
1321# in output directory, skip its clean in that case
1322resolve_btfids_clean:
1323ifneq ($(wildcard $(resolve_btfids_O)),)
1324	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1325endif
1326
1327# Clear a bunch of variables before executing the submake
1328ifeq ($(quiet),silent_)
1329tools_silent=s
1330endif
1331
1332tools/: FORCE
1333	$(Q)mkdir -p $(objtree)/tools
1334	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1335
1336tools/%: FORCE
1337	$(Q)mkdir -p $(objtree)/tools
1338	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1339
1340# ---------------------------------------------------------------------------
1341# Kernel selftest
1342
1343PHONY += kselftest
1344kselftest:
1345	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1346
1347kselftest-%: FORCE
1348	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1349
1350PHONY += kselftest-merge
1351kselftest-merge:
1352	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1353	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1354		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1355	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1356
1357# ---------------------------------------------------------------------------
1358# Devicetree files
1359
1360ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1361dtstree := arch/$(SRCARCH)/boot/dts
1362endif
1363
1364ifneq ($(dtstree),)
1365
1366%.dtb: include/config/kernel.release scripts_dtc
1367	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1368
1369%.dtbo: include/config/kernel.release scripts_dtc
1370	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1371
1372PHONY += dtbs dtbs_install dtbs_check
1373dtbs: include/config/kernel.release scripts_dtc
1374	$(Q)$(MAKE) $(build)=$(dtstree)
1375
1376ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1377export CHECK_DTBS=y
1378dtbs: dt_binding_check
1379endif
1380
1381dtbs_check: dtbs
1382
1383dtbs_install:
1384	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1385
1386ifdef CONFIG_OF_EARLY_FLATTREE
1387all: dtbs
1388endif
1389
1390endif
1391
1392PHONY += scripts_dtc
1393scripts_dtc: scripts_basic
1394	$(Q)$(MAKE) $(build)=scripts/dtc
1395
1396ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1397export CHECK_DT_BINDING=y
1398endif
1399
1400PHONY += dt_binding_check
1401dt_binding_check: scripts_dtc
1402	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1403
1404# ---------------------------------------------------------------------------
1405# Modules
1406
1407ifdef CONFIG_MODULES
1408
1409# By default, build modules as well
1410
1411all: modules
1412
1413# When we're building modules with modversions, we need to consider
1414# the built-in objects during the descend as well, in order to
1415# make sure the checksums are up to date before we record them.
1416ifdef CONFIG_MODVERSIONS
1417  KBUILD_BUILTIN := 1
1418endif
1419
1420# Build modules
1421#
1422# A module can be listed more than once in obj-m resulting in
1423# duplicate lines in modules.order files.  Those are removed
1424# using awk while concatenating to the final file.
1425
1426PHONY += modules
1427modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1428
1429cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1430
1431modules.order: $(subdir-modorder) FORCE
1432	$(call if_changed,modules_order)
1433
1434targets += modules.order
1435
1436# Target to prepare building external modules
1437PHONY += modules_prepare
1438modules_prepare: prepare
1439	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1440
1441export modules_sign_only :=
1442
1443ifeq ($(CONFIG_MODULE_SIG),y)
1444PHONY += modules_sign
1445modules_sign: modules_install
1446	@:
1447
1448# modules_sign is a subset of modules_install.
1449# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1450ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1451modules_sign_only := y
1452endif
1453endif
1454
1455modinst_pre :=
1456ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1457modinst_pre := __modinst_pre
1458endif
1459
1460modules_install: $(modinst_pre)
1461PHONY += __modinst_pre
1462__modinst_pre:
1463	@rm -rf $(MODLIB)/kernel
1464	@rm -f $(MODLIB)/source
1465	@mkdir -p $(MODLIB)/kernel
1466	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1467	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1468		rm -f $(MODLIB)/build ; \
1469		ln -s $(CURDIR) $(MODLIB)/build ; \
1470	fi
1471	@sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1472	@cp -f modules.builtin $(MODLIB)/
1473	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1474
1475endif # CONFIG_MODULES
1476
1477###
1478# Cleaning is done on three levels.
1479# make clean     Delete most generated files
1480#                Leave enough to build external modules
1481# make mrproper  Delete the current configuration, and all generated files
1482# make distclean Remove editor backup files, patch leftover files and the like
1483
1484# Directories & files removed with 'make clean'
1485CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1486	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1487	       compile_commands.json .thinlto-cache
1488
1489# Directories & files removed with 'make mrproper'
1490MRPROPER_FILES += include/config include/generated          \
1491		  arch/$(SRCARCH)/include/generated .tmp_objdiff \
1492		  debian snap tar-install \
1493		  .config .config.old .version \
1494		  Module.symvers \
1495		  certs/signing_key.pem \
1496		  certs/x509.genkey \
1497		  vmlinux-gdb.py \
1498		  *.spec
1499
1500# clean - Delete most, but leave enough to build external modules
1501#
1502clean: rm-files := $(CLEAN_FILES)
1503
1504PHONY += archclean vmlinuxclean
1505
1506vmlinuxclean:
1507	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1508	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1509
1510clean: archclean vmlinuxclean resolve_btfids_clean
1511
1512# mrproper - Delete all generated files, including .config
1513#
1514mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1515mrproper-dirs      := $(addprefix _mrproper_,scripts)
1516
1517PHONY += $(mrproper-dirs) mrproper
1518$(mrproper-dirs):
1519	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1520
1521mrproper: clean $(mrproper-dirs)
1522	$(call cmd,rmfiles)
1523
1524# distclean
1525#
1526PHONY += distclean
1527
1528distclean: mrproper
1529	@find . $(RCS_FIND_IGNORE) \
1530		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1531		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1532		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1533		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1534		-type f -print | xargs rm -f
1535
1536
1537# Packaging of the kernel to various formats
1538# ---------------------------------------------------------------------------
1539
1540%src-pkg: FORCE
1541	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1542%pkg: include/config/kernel.release FORCE
1543	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1544
1545# Brief documentation of the typical targets used
1546# ---------------------------------------------------------------------------
1547
1548boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1549boards := $(sort $(notdir $(boards)))
1550board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1551board-dirs := $(sort $(notdir $(board-dirs:/=)))
1552
1553PHONY += help
1554help:
1555	@echo  'Cleaning targets:'
1556	@echo  '  clean		  - Remove most generated files but keep the config and'
1557	@echo  '                    enough build support to build external modules'
1558	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1559	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1560	@echo  ''
1561	@echo  'Configuration targets:'
1562	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1563	@echo  ''
1564	@echo  'Other generic targets:'
1565	@echo  '  all		  - Build all targets marked with [*]'
1566	@echo  '* vmlinux	  - Build the bare kernel'
1567	@echo  '* modules	  - Build all modules'
1568	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1569	@echo  '  dir/            - Build all files in dir and below'
1570	@echo  '  dir/file.[ois]  - Build specified target only'
1571	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1572	@echo  '                    (requires compiler support for LLVM assembly generation)'
1573	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1574	@echo  '                    (requires a recent binutils and recent build (System.map))'
1575	@echo  '  dir/file.ko     - Build module including final link'
1576	@echo  '  modules_prepare - Set up for building external modules'
1577	@echo  '  tags/TAGS	  - Generate tags file for editors'
1578	@echo  '  cscope	  - Generate cscope index'
1579	@echo  '  gtags           - Generate GNU GLOBAL index'
1580	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1581	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1582	@echo  '  image_name	  - Output the image name (use with make -s)'
1583	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1584	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1585	 echo  ''
1586	@echo  'Static analysers:'
1587	@echo  '  checkstack      - Generate a list of stack hogs'
1588	@echo  '  versioncheck    - Sanity check on version.h usage'
1589	@echo  '  includecheck    - Check for duplicate included header files'
1590	@echo  '  export_report   - List the usages of all exported symbols'
1591	@echo  '  headerdep       - Detect inclusion cycles in headers'
1592	@echo  '  coccicheck      - Check with Coccinelle'
1593	@echo  '  clang-analyzer  - Check with clang static analyzer'
1594	@echo  '  clang-tidy      - Check with clang-tidy'
1595	@echo  ''
1596	@echo  'Tools:'
1597	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1598	@echo  ''
1599	@echo  'Kernel selftest:'
1600	@echo  '  kselftest         - Build and run kernel selftest'
1601	@echo  '                      Build, install, and boot kernel before'
1602	@echo  '                      running kselftest on it'
1603	@echo  '                      Run as root for full coverage'
1604	@echo  '  kselftest-all     - Build kernel selftest'
1605	@echo  '  kselftest-install - Build and install kernel selftest'
1606	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1607	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1608	@echo  '		      kselftest to existing .config.'
1609	@echo  ''
1610	@$(if $(dtstree), \
1611		echo 'Devicetree:'; \
1612		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1613		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1614		echo '  dt_binding_check - Validate device tree binding documents'; \
1615		echo '  dtbs_check       - Validate device tree source files';\
1616		echo '')
1617
1618	@echo 'Userspace tools targets:'
1619	@echo '  use "make tools/help"'
1620	@echo '  or  "cd tools; make help"'
1621	@echo  ''
1622	@echo  'Kernel packaging:'
1623	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1624	@echo  ''
1625	@echo  'Documentation targets:'
1626	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1627	@echo  ''
1628	@echo  'Architecture specific targets ($(SRCARCH)):'
1629	@$(or $(archhelp),\
1630		echo '  No architecture specific help defined for $(SRCARCH)')
1631	@echo  ''
1632	@$(if $(boards), \
1633		$(foreach b, $(boards), \
1634		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1635		echo '')
1636	@$(if $(board-dirs), \
1637		$(foreach b, $(board-dirs), \
1638		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1639		printf "  %-16s - Show all of the above\\n" help-boards; \
1640		echo '')
1641
1642	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1643	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1644	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1645	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1646	@echo  '                       (sparse by default)'
1647	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1648	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1649	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1650	@echo  '		1: warnings which may be relevant and do not occur too often'
1651	@echo  '		2: warnings which occur quite often but may still be relevant'
1652	@echo  '		3: more obscure warnings, can most likely be ignored'
1653	@echo  '		Multiple levels can be combined with W=12 or W=123'
1654	@echo  ''
1655	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1656	@echo  'For further info see the ./README file'
1657
1658
1659help-board-dirs := $(addprefix help-,$(board-dirs))
1660
1661help-boards: $(help-board-dirs)
1662
1663boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1664
1665$(help-board-dirs): help-%:
1666	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1667	@$(if $(boards-per-dir), \
1668		$(foreach b, $(boards-per-dir), \
1669		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1670		echo '')
1671
1672
1673# Documentation targets
1674# ---------------------------------------------------------------------------
1675DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1676	       linkcheckdocs dochelp refcheckdocs
1677PHONY += $(DOC_TARGETS)
1678$(DOC_TARGETS):
1679	$(Q)$(MAKE) $(build)=Documentation $@
1680
1681# Misc
1682# ---------------------------------------------------------------------------
1683
1684PHONY += scripts_gdb
1685scripts_gdb: prepare0
1686	$(Q)$(MAKE) $(build)=scripts/gdb
1687	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1688
1689ifdef CONFIG_GDB_SCRIPTS
1690all: scripts_gdb
1691endif
1692
1693else # KBUILD_EXTMOD
1694
1695###
1696# External module support.
1697# When building external modules the kernel used as basis is considered
1698# read-only, and no consistency checks are made and the make
1699# system is not used on the basis kernel. If updates are required
1700# in the basis kernel ordinary make commands (without M=...) must be used.
1701
1702# We are always building only modules.
1703KBUILD_BUILTIN :=
1704KBUILD_MODULES := 1
1705
1706build-dirs := $(KBUILD_EXTMOD)
1707$(MODORDER): descend
1708	@:
1709
1710compile_commands.json: $(extmod_prefix)compile_commands.json
1711PHONY += compile_commands.json
1712
1713clean-dirs := $(KBUILD_EXTMOD)
1714clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1715	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1716
1717PHONY += prepare
1718# now expand this into a simple variable to reduce the cost of shell evaluations
1719prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1720prepare:
1721	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1722		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1723		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1724		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1725	fi
1726
1727PHONY += help
1728help:
1729	@echo  '  Building external modules.'
1730	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1731	@echo  ''
1732	@echo  '  modules         - default target, build the module(s)'
1733	@echo  '  modules_install - install the module'
1734	@echo  '  clean           - remove generated files in module directory only'
1735	@echo  ''
1736
1737# no-op for external module builds
1738PHONY += modules_prepare
1739
1740endif # KBUILD_EXTMOD
1741
1742# ---------------------------------------------------------------------------
1743# Modules
1744
1745PHONY += modules modules_install
1746
1747ifdef CONFIG_MODULES
1748
1749modules: modules_check
1750	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1751
1752PHONY += modules_check
1753modules_check: $(MODORDER)
1754	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1755
1756quiet_cmd_depmod = DEPMOD  $(MODLIB)
1757      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1758                   $(KERNELRELEASE)
1759
1760modules_install:
1761	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1762	$(call cmd,depmod)
1763
1764else # CONFIG_MODULES
1765
1766# Modules not configured
1767# ---------------------------------------------------------------------------
1768
1769modules modules_install:
1770	@echo >&2 '***'
1771	@echo >&2 '*** The present kernel configuration has modules disabled.'
1772	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1773	@echo >&2 '*** to enable CONFIG_MODULES.'
1774	@echo >&2 '***'
1775	@exit 1
1776
1777endif # CONFIG_MODULES
1778
1779# Single targets
1780# ---------------------------------------------------------------------------
1781# To build individual files in subdirectories, you can do like this:
1782#
1783#   make foo/bar/baz.s
1784#
1785# The supported suffixes for single-target are listed in 'single-targets'
1786#
1787# To build only under specific subdirectories, you can do like this:
1788#
1789#   make foo/bar/baz/
1790
1791ifdef single-build
1792
1793# .ko is special because modpost is needed
1794single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1795single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1796		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1797
1798$(single-ko): single_modpost
1799	@:
1800$(single-no-ko): descend
1801	@:
1802
1803ifeq ($(KBUILD_EXTMOD),)
1804# For the single build of in-tree modules, use a temporary file to avoid
1805# the situation of modules_install installing an invalid modules.order.
1806MODORDER := .modules.tmp
1807endif
1808
1809PHONY += single_modpost
1810single_modpost: $(single-no-ko) modules_prepare
1811	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1812	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1813
1814KBUILD_MODULES := 1
1815
1816export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1817
1818# trim unrelated directories
1819build-dirs := $(foreach d, $(build-dirs), \
1820			$(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1821
1822endif
1823
1824ifndef CONFIG_MODULES
1825KBUILD_MODULES :=
1826endif
1827
1828# Handle descending into subdirectories listed in $(build-dirs)
1829# Preset locale variables to speed up the build process. Limit locale
1830# tweaks to this spot to avoid wrong language settings when running
1831# make menuconfig etc.
1832# Error messages still appears in the original language
1833PHONY += descend $(build-dirs)
1834descend: $(build-dirs)
1835$(build-dirs): prepare
1836	$(Q)$(MAKE) $(build)=$@ \
1837	single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1838	need-builtin=1 need-modorder=1
1839
1840clean-dirs := $(addprefix _clean_, $(clean-dirs))
1841PHONY += $(clean-dirs) clean
1842$(clean-dirs):
1843	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1844
1845clean: $(clean-dirs)
1846	$(call cmd,rmfiles)
1847	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1848		\( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1849		-o -name '*.ko.*' \
1850		-o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1851		-o -name '*.dwo' -o -name '*.lst' \
1852		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
1853		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1854		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
1855		-o -name '*.asn1.[ch]' \
1856		-o -name '*.symtypes' -o -name 'modules.order' \
1857		-o -name '.tmp_*.o.*' \
1858		-o -name '*.c.[012]*.*' \
1859		-o -name '*.ll' \
1860		-o -name '*.gcno' \
1861		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
1862
1863# Generate tags for editors
1864# ---------------------------------------------------------------------------
1865quiet_cmd_tags = GEN     $@
1866      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1867
1868tags TAGS cscope gtags: FORCE
1869	$(call cmd,tags)
1870
1871# Script to generate missing namespace dependencies
1872# ---------------------------------------------------------------------------
1873
1874PHONY += nsdeps
1875nsdeps: export KBUILD_NSDEPS=1
1876nsdeps: modules
1877	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1878
1879# Clang Tooling
1880# ---------------------------------------------------------------------------
1881
1882quiet_cmd_gen_compile_commands = GEN     $@
1883      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1884
1885$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1886	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1887	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1888	$(call if_changed,gen_compile_commands)
1889
1890targets += $(extmod_prefix)compile_commands.json
1891
1892PHONY += clang-tidy clang-analyzer
1893
1894ifdef CONFIG_CC_IS_CLANG
1895quiet_cmd_clang_tools = CHECK   $<
1896      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1897
1898clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1899	$(call cmd,clang_tools)
1900else
1901clang-tidy clang-analyzer:
1902	@echo "$@ requires CC=clang" >&2
1903	@false
1904endif
1905
1906# Scripts to check various things for consistency
1907# ---------------------------------------------------------------------------
1908
1909PHONY += includecheck versioncheck coccicheck export_report
1910
1911includecheck:
1912	find $(srctree)/* $(RCS_FIND_IGNORE) \
1913		-name '*.[hcS]' -type f -print | sort \
1914		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1915
1916versioncheck:
1917	find $(srctree)/* $(RCS_FIND_IGNORE) \
1918		-name '*.[hcS]' -type f -print | sort \
1919		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1920
1921coccicheck:
1922	$(Q)$(BASH) $(srctree)/scripts/$@
1923
1924export_report:
1925	$(PERL) $(srctree)/scripts/export_report.pl
1926
1927PHONY += checkstack kernelrelease kernelversion image_name
1928
1929# UML needs a little special treatment here.  It wants to use the host
1930# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
1931# else wants $(ARCH), including people doing cross-builds, which means
1932# that $(SUBARCH) doesn't work here.
1933ifeq ($(ARCH), um)
1934CHECKSTACK_ARCH := $(SUBARCH)
1935else
1936CHECKSTACK_ARCH := $(ARCH)
1937endif
1938checkstack:
1939	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1940	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1941
1942kernelrelease:
1943	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1944
1945kernelversion:
1946	@echo $(KERNELVERSION)
1947
1948image_name:
1949	@echo $(KBUILD_IMAGE)
1950
1951quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
1952      cmd_rmfiles = rm -rf $(rm-files)
1953
1954# read saved command lines for existing targets
1955existing-targets := $(wildcard $(sort $(targets)))
1956
1957-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1958
1959endif # config-build
1960endif # mixed-build
1961endif # need-sub-make
1962
1963PHONY += FORCE
1964FORCE:
1965
1966# Declare the contents of the PHONY variable as phony.  We keep that
1967# information in a variable so we can use it in if_changed and friends.
1968.PHONY: $(PHONY)
1969