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kbuild: make distclean work against $(objtree) instead of $(srctree)
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1# SPDX-License-Identifier: GPL-2.0
2VERSION = 5
3PATCHLEVEL = 12
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Frozen Wasteland
7
8# *DOCUMENTATION*
9# To see a list of typical targets execute "make help"
10# More info can be located in ./README
11# Comments in this file are targeted only to the developer, do not
12# expect to learn how to build the kernel reading this file.
13
14$(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 $(error building multiple external modules is not supported))
131
132export KBUILD_EXTMOD
133
134# Kbuild will save output files in the current working directory.
135# This does not need to match to the root of the kernel source tree.
136#
137# For example, you can do this:
138#
139# cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
140#
141# If you want to save output files in a different location, there are
142# two syntaxes to specify it.
143#
144# 1) O=
145# Use "make O=dir/to/store/output/files/"
146#
147# 2) Set KBUILD_OUTPUT
148# Set the environment variable KBUILD_OUTPUT to point to the output directory.
149# export KBUILD_OUTPUT=dir/to/store/output/files/; make
150#
151# The O= assignment takes precedence over the KBUILD_OUTPUT environment
152# variable.
153
154# Do we want to change the working directory?
155ifeq ("$(origin O)", "command line")
156 KBUILD_OUTPUT := $(O)
157endif
158
159ifneq ($(KBUILD_OUTPUT),)
160# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
161# expand a shell special character '~'. We use a somewhat tedious way here.
162abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
163$(if $(abs_objtree),, \
164 $(error failed to create output directory "$(KBUILD_OUTPUT)"))
165
166# $(realpath ...) resolves symlinks
167abs_objtree := $(realpath $(abs_objtree))
168else
169abs_objtree := $(CURDIR)
170endif # ifneq ($(KBUILD_OUTPUT),)
171
172ifeq ($(abs_objtree),$(CURDIR))
173# Suppress "Entering directory ..." unless we are changing the work directory.
174MAKEFLAGS += --no-print-directory
175else
176need-sub-make := 1
177endif
178
179this-makefile := $(lastword $(MAKEFILE_LIST))
180abs_srctree := $(realpath $(dir $(this-makefile)))
181
182ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
183$(error source directory cannot contain spaces or colons)
184endif
185
186ifneq ($(abs_srctree),$(abs_objtree))
187# Look for make include files relative to root of kernel src
188#
189# This does not become effective immediately because MAKEFLAGS is re-parsed
190# once after the Makefile is read. We need to invoke sub-make.
191MAKEFLAGS += --include-dir=$(abs_srctree)
192need-sub-make := 1
193endif
194
195ifneq ($(filter 3.%,$(MAKE_VERSION)),)
196# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
197# We need to invoke sub-make to avoid implicit rules in the top Makefile.
198need-sub-make := 1
199# Cancel implicit rules for this Makefile.
200$(this-makefile): ;
201endif
202
203export abs_srctree abs_objtree
204export sub_make_done := 1
205
206ifeq ($(need-sub-make),1)
207
208PHONY += $(MAKECMDGOALS) __sub-make
209
210$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
211 @:
212
213# Invoke a second make in the output directory, passing relevant variables
214__sub-make:
215 $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
216
217endif # need-sub-make
218endif # sub_make_done
219
220# We process the rest of the Makefile if this is the final invocation of make
221ifeq ($(need-sub-make),)
222
223# Do not print "Entering directory ...",
224# but we want to display it when entering to the output directory
225# so that IDEs/editors are able to understand relative filenames.
226MAKEFLAGS += --no-print-directory
227
228ifeq ($(abs_srctree),$(abs_objtree))
229 # building in the source tree
230 srctree := .
231 building_out_of_srctree :=
232else
233 ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
234 # building in a subdirectory of the source tree
235 srctree := ..
236 else
237 srctree := $(abs_srctree)
238 endif
239 building_out_of_srctree := 1
240endif
241
242ifneq ($(KBUILD_ABS_SRCTREE),)
243srctree := $(abs_srctree)
244endif
245
246objtree := .
247VPATH := $(srctree)
248
249export building_out_of_srctree srctree objtree VPATH
250
251# To make sure we do not include .config for any of the *config targets
252# catch them early, and hand them over to scripts/kconfig/Makefile
253# It is allowed to specify more targets when calling make, including
254# mixing *config targets and build targets.
255# For example 'make oldconfig all'.
256# Detect when mixed targets is specified, and make a second invocation
257# of make so .config is not included in this case either (for *config).
258
259version_h := include/generated/uapi/linux/version.h
260
261clean-targets := %clean mrproper cleandocs
262no-dot-config-targets := $(clean-targets) \
263 cscope gtags TAGS tags help% %docs check% coccicheck \
264 $(version_h) headers headers_% archheaders archscripts \
265 %asm-generic kernelversion %src-pkg dt_binding_check \
266 outputmakefile
267# Installation targets should not require compiler. Unfortunately, vdso_install
268# is an exception where build artifacts may be updated. This must be fixed.
269no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
270 headers_install modules_install kernelrelease image_name
271no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
272 image_name
273single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
274
275config-build :=
276mixed-build :=
277need-config := 1
278need-compiler := 1
279may-sync-config := 1
280single-build :=
281
282ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
283 ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
284 need-config :=
285 endif
286endif
287
288ifneq ($(filter $(no-compiler-targets), $(MAKECMDGOALS)),)
289 ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
290 need-compiler :=
291 endif
292endif
293
294ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
295 ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
296 may-sync-config :=
297 endif
298endif
299
300ifneq ($(KBUILD_EXTMOD),)
301 may-sync-config :=
302endif
303
304ifeq ($(KBUILD_EXTMOD),)
305 ifneq ($(filter %config,$(MAKECMDGOALS)),)
306 config-build := 1
307 ifneq ($(words $(MAKECMDGOALS)),1)
308 mixed-build := 1
309 endif
310 endif
311endif
312
313# We cannot build single targets and the others at the same time
314ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
315 single-build := 1
316 ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
317 mixed-build := 1
318 endif
319endif
320
321# For "make -j clean all", "make -j mrproper defconfig all", etc.
322ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
323 ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
324 mixed-build := 1
325 endif
326endif
327
328# install and modules_install need also be processed one by one
329ifneq ($(filter install,$(MAKECMDGOALS)),)
330 ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
331 mixed-build := 1
332 endif
333endif
334
335ifdef mixed-build
336# ===========================================================================
337# We're called with mixed targets (*config and build targets).
338# Handle them one by one.
339
340PHONY += $(MAKECMDGOALS) __build_one_by_one
341
342$(MAKECMDGOALS): __build_one_by_one
343 @:
344
345__build_one_by_one:
346 $(Q)set -e; \
347 for i in $(MAKECMDGOALS); do \
348 $(MAKE) -f $(srctree)/Makefile $$i; \
349 done
350
351else # !mixed-build
352
353include $(srctree)/scripts/Kbuild.include
354
355# Read KERNELRELEASE from include/config/kernel.release (if it exists)
356KERNELRELEASE = $(shell cat include/config/kernel.release 2> /dev/null)
357KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
358export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
359
360include $(srctree)/scripts/subarch.include
361
362# Cross compiling and selecting different set of gcc/bin-utils
363# ---------------------------------------------------------------------------
364#
365# When performing cross compilation for other architectures ARCH shall be set
366# to the target architecture. (See arch/* for the possibilities).
367# ARCH can be set during invocation of make:
368# make ARCH=ia64
369# Another way is to have ARCH set in the environment.
370# The default ARCH is the host where make is executed.
371
372# CROSS_COMPILE specify the prefix used for all executables used
373# during compilation. Only gcc and related bin-utils executables
374# are prefixed with $(CROSS_COMPILE).
375# CROSS_COMPILE can be set on the command line
376# make CROSS_COMPILE=ia64-linux-
377# Alternatively CROSS_COMPILE can be set in the environment.
378# Default value for CROSS_COMPILE is not to prefix executables
379# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
380ARCH ?= $(SUBARCH)
381
382# Architecture as present in compile.h
383UTS_MACHINE := $(ARCH)
384SRCARCH := $(ARCH)
385
386# Additional ARCH settings for x86
387ifeq ($(ARCH),i386)
388 SRCARCH := x86
389endif
390ifeq ($(ARCH),x86_64)
391 SRCARCH := x86
392endif
393
394# Additional ARCH settings for sparc
395ifeq ($(ARCH),sparc32)
396 SRCARCH := sparc
397endif
398ifeq ($(ARCH),sparc64)
399 SRCARCH := sparc
400endif
401
402export cross_compiling :=
403ifneq ($(SRCARCH),$(SUBARCH))
404cross_compiling := 1
405endif
406
407KCONFIG_CONFIG ?= .config
408export KCONFIG_CONFIG
409
410# SHELL used by kbuild
411CONFIG_SHELL := sh
412
413HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
414HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
415HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
416
417ifneq ($(LLVM),)
418HOSTCC = clang
419HOSTCXX = clang++
420else
421HOSTCC = gcc
422HOSTCXX = g++
423endif
424
425export KBUILD_USERCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
426 -O2 -fomit-frame-pointer -std=gnu89
427export KBUILD_USERLDFLAGS :=
428
429KBUILD_HOSTCFLAGS := $(KBUILD_USERCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
430KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
431KBUILD_HOSTLDFLAGS := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
432KBUILD_HOSTLDLIBS := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
433
434# Make variables (CC, etc...)
435CPP = $(CC) -E
436ifneq ($(LLVM),)
437CC = clang
438LD = ld.lld
439AR = llvm-ar
440NM = llvm-nm
441OBJCOPY = llvm-objcopy
442OBJDUMP = llvm-objdump
443READELF = llvm-readelf
444STRIP = llvm-strip
445else
446CC = $(CROSS_COMPILE)gcc
447LD = $(CROSS_COMPILE)ld
448AR = $(CROSS_COMPILE)ar
449NM = $(CROSS_COMPILE)nm
450OBJCOPY = $(CROSS_COMPILE)objcopy
451OBJDUMP = $(CROSS_COMPILE)objdump
452READELF = $(CROSS_COMPILE)readelf
453STRIP = $(CROSS_COMPILE)strip
454endif
455PAHOLE = pahole
456RESOLVE_BTFIDS = $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
457LEX = flex
458YACC = bison
459AWK = awk
460INSTALLKERNEL := installkernel
461DEPMOD = depmod
462PERL = perl
463PYTHON3 = python3
464CHECK = sparse
465BASH = bash
466KGZIP = gzip
467KBZIP2 = bzip2
468KLZOP = lzop
469LZMA = lzma
470LZ4 = lz4c
471XZ = xz
472ZSTD = zstd
473
474CHECKFLAGS := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
475 -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
476NOSTDINC_FLAGS :=
477CFLAGS_MODULE =
478AFLAGS_MODULE =
479LDFLAGS_MODULE =
480CFLAGS_KERNEL =
481AFLAGS_KERNEL =
482LDFLAGS_vmlinux =
483
484# Use USERINCLUDE when you must reference the UAPI directories only.
485USERINCLUDE := \
486 -I$(srctree)/arch/$(SRCARCH)/include/uapi \
487 -I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
488 -I$(srctree)/include/uapi \
489 -I$(objtree)/include/generated/uapi \
490 -include $(srctree)/include/linux/compiler-version.h \
491 -include $(srctree)/include/linux/kconfig.h
492
493# Use LINUXINCLUDE when you must reference the include/ directory.
494# Needed to be compatible with the O= option
495LINUXINCLUDE := \
496 -I$(srctree)/arch/$(SRCARCH)/include \
497 -I$(objtree)/arch/$(SRCARCH)/include/generated \
498 $(if $(building_out_of_srctree),-I$(srctree)/include) \
499 -I$(objtree)/include \
500 $(USERINCLUDE)
501
502KBUILD_AFLAGS := -D__ASSEMBLY__ -fno-PIE
503KBUILD_CFLAGS := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
504 -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
505 -Werror=implicit-function-declaration -Werror=implicit-int \
506 -Werror=return-type -Wno-format-security \
507 -std=gnu89
508KBUILD_CPPFLAGS := -D__KERNEL__
509KBUILD_AFLAGS_KERNEL :=
510KBUILD_CFLAGS_KERNEL :=
511KBUILD_AFLAGS_MODULE := -DMODULE
512KBUILD_CFLAGS_MODULE := -DMODULE
513KBUILD_LDFLAGS_MODULE :=
514KBUILD_LDFLAGS :=
515CLANG_FLAGS :=
516
517export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC
518export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
519export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
520export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
521export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
522
523export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
524export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
525export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
526export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
527export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
528
529# Files to ignore in find ... statements
530
531export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o \
532 -name CVS -o -name .pc -o -name .hg -o -name .git \) \
533 -prune -o
534export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
535 --exclude CVS --exclude .pc --exclude .hg --exclude .git
536
537# ===========================================================================
538# Rules shared between *config targets and build targets
539
540# Basic helpers built in scripts/basic/
541PHONY += scripts_basic
542scripts_basic:
543 $(Q)$(MAKE) $(build)=scripts/basic
544 $(Q)rm -f .tmp_quiet_recordmcount
545
546PHONY += outputmakefile
547# Before starting out-of-tree build, make sure the source tree is clean.
548# outputmakefile generates a Makefile in the output directory, if using a
549# separate output directory. This allows convenient use of make in the
550# output directory.
551# At the same time when output Makefile generated, generate .gitignore to
552# ignore whole output directory
553outputmakefile:
554ifdef building_out_of_srctree
555 $(Q)if [ -f $(srctree)/.config -o \
556 -d $(srctree)/include/config -o \
557 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
558 echo >&2 "***"; \
559 echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
560 echo >&2 "*** in $(abs_srctree)";\
561 echo >&2 "***"; \
562 false; \
563 fi
564 $(Q)ln -fsn $(srctree) source
565 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
566 $(Q)test -e .gitignore || \
567 { echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
568endif
569
570# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
571# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
572# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
573# and from include/config/auto.conf.cmd to detect the compiler upgrade.
574CC_VERSION_TEXT = $(subst $(pound),,$(shell $(CC) --version 2>/dev/null | head -n 1))
575
576ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
577ifneq ($(CROSS_COMPILE),)
578CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%))
579endif
580ifeq ($(LLVM_IAS),1)
581CLANG_FLAGS += -integrated-as
582else
583CLANG_FLAGS += -no-integrated-as
584GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit))
585CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE))
586endif
587CLANG_FLAGS += -Werror=unknown-warning-option
588KBUILD_CFLAGS += $(CLANG_FLAGS)
589KBUILD_AFLAGS += $(CLANG_FLAGS)
590export CLANG_FLAGS
591endif
592
593# Include this also for config targets because some architectures need
594# cc-cross-prefix to determine CROSS_COMPILE.
595ifdef need-compiler
596include $(srctree)/scripts/Makefile.compiler
597endif
598
599ifdef config-build
600# ===========================================================================
601# *config targets only - make sure prerequisites are updated, and descend
602# in scripts/kconfig to make the *config target
603
604# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
605# KBUILD_DEFCONFIG may point out an alternative default configuration
606# used for 'make defconfig'
607include $(srctree)/arch/$(SRCARCH)/Makefile
608export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
609
610config: outputmakefile scripts_basic FORCE
611 $(Q)$(MAKE) $(build)=scripts/kconfig $@
612
613%config: outputmakefile scripts_basic FORCE
614 $(Q)$(MAKE) $(build)=scripts/kconfig $@
615
616else #!config-build
617# ===========================================================================
618# Build targets only - this includes vmlinux, arch specific targets, clean
619# targets and others. In general all targets except *config targets.
620
621# If building an external module we do not care about the all: rule
622# but instead __all depend on modules
623PHONY += all
624ifeq ($(KBUILD_EXTMOD),)
625__all: all
626else
627__all: modules
628endif
629
630# Decide whether to build built-in, modular, or both.
631# Normally, just do built-in.
632
633KBUILD_MODULES :=
634KBUILD_BUILTIN := 1
635
636# If we have only "make modules", don't compile built-in objects.
637ifeq ($(MAKECMDGOALS),modules)
638 KBUILD_BUILTIN :=
639endif
640
641# If we have "make <whatever> modules", compile modules
642# in addition to whatever we do anyway.
643# Just "make" or "make all" shall build modules as well
644
645ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
646 KBUILD_MODULES := 1
647endif
648
649ifeq ($(MAKECMDGOALS),)
650 KBUILD_MODULES := 1
651endif
652
653export KBUILD_MODULES KBUILD_BUILTIN
654
655ifdef need-config
656include include/config/auto.conf
657endif
658
659ifeq ($(KBUILD_EXTMOD),)
660# Objects we will link into vmlinux / subdirs we need to visit
661core-y := init/ usr/
662drivers-y := drivers/ sound/
663drivers-$(CONFIG_SAMPLES) += samples/
664drivers-$(CONFIG_NET) += net/
665drivers-y += virt/
666libs-y := lib/
667endif # KBUILD_EXTMOD
668
669# The all: target is the default when no target is given on the
670# command line.
671# This allow a user to issue only 'make' to build a kernel including modules
672# Defaults to vmlinux, but the arch makefile usually adds further targets
673all: vmlinux
674
675CFLAGS_GCOV := -fprofile-arcs -ftest-coverage \
676 $(call cc-option,-fno-tree-loop-im) \
677 $(call cc-disable-warning,maybe-uninitialized,)
678export CFLAGS_GCOV
679
680# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
681ifdef CONFIG_FUNCTION_TRACER
682 CC_FLAGS_FTRACE := -pg
683endif
684
685RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
686RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
687RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
688RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
689RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
690RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
691export RETPOLINE_CFLAGS
692export RETPOLINE_VDSO_CFLAGS
693
694include $(srctree)/arch/$(SRCARCH)/Makefile
695
696ifdef need-config
697ifdef may-sync-config
698# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
699# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
700# because some architectures define CROSS_COMPILE there.
701include include/config/auto.conf.cmd
702
703$(KCONFIG_CONFIG):
704 @echo >&2 '***'
705 @echo >&2 '*** Configuration file "$@" not found!'
706 @echo >&2 '***'
707 @echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
708 @echo >&2 '*** "make menuconfig" or "make xconfig").'
709 @echo >&2 '***'
710 @/bin/false
711
712# The actual configuration files used during the build are stored in
713# include/generated/ and include/config/. Update them if .config is newer than
714# include/config/auto.conf (which mirrors .config).
715#
716# This exploits the 'multi-target pattern rule' trick.
717# The syncconfig should be executed only once to make all the targets.
718# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
719quiet_cmd_syncconfig = SYNC $@
720 cmd_syncconfig = $(MAKE) -f $(srctree)/Makefile syncconfig
721
722%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
723 +$(call cmd,syncconfig)
724else # !may-sync-config
725# External modules and some install targets need include/generated/autoconf.h
726# and include/config/auto.conf but do not care if they are up-to-date.
727# Use auto.conf to trigger the test
728PHONY += include/config/auto.conf
729
730include/config/auto.conf:
731 $(Q)test -e include/generated/autoconf.h -a -e $@ || ( \
732 echo >&2; \
733 echo >&2 " ERROR: Kernel configuration is invalid."; \
734 echo >&2 " include/generated/autoconf.h or $@ are missing.";\
735 echo >&2 " Run 'make oldconfig && make prepare' on kernel src to fix it."; \
736 echo >&2 ; \
737 /bin/false)
738
739endif # may-sync-config
740endif # need-config
741
742KBUILD_CFLAGS += $(call cc-option,-fno-delete-null-pointer-checks,)
743KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
744KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
745KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
746KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
747
748ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
749KBUILD_CFLAGS += -O2
750else ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3
751KBUILD_CFLAGS += -O3
752else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
753KBUILD_CFLAGS += -Os
754endif
755
756# Tell gcc to never replace conditional load with a non-conditional one
757KBUILD_CFLAGS += $(call cc-option,--param=allow-store-data-races=0)
758KBUILD_CFLAGS += $(call cc-option,-fno-allow-store-data-races)
759
760ifdef CONFIG_READABLE_ASM
761# Disable optimizations that make assembler listings hard to read.
762# reorder blocks reorders the control in the function
763# ipa clone creates specialized cloned functions
764# partial inlining inlines only parts of functions
765KBUILD_CFLAGS += $(call cc-option,-fno-reorder-blocks,) \
766 $(call cc-option,-fno-ipa-cp-clone,) \
767 $(call cc-option,-fno-partial-inlining)
768endif
769
770ifneq ($(CONFIG_FRAME_WARN),0)
771KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
772endif
773
774stackp-flags-y := -fno-stack-protector
775stackp-flags-$(CONFIG_STACKPROTECTOR) := -fstack-protector
776stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG) := -fstack-protector-strong
777
778KBUILD_CFLAGS += $(stackp-flags-y)
779
780ifdef CONFIG_CC_IS_CLANG
781KBUILD_CPPFLAGS += -Qunused-arguments
782KBUILD_CFLAGS += -Wno-format-invalid-specifier
783KBUILD_CFLAGS += -Wno-gnu
784# CLANG uses a _MergedGlobals as optimization, but this breaks modpost, as the
785# source of a reference will be _MergedGlobals and not on of the whitelisted names.
786# See modpost pattern 2
787KBUILD_CFLAGS += -mno-global-merge
788else
789
790# Warn about unmarked fall-throughs in switch statement.
791# Disabled for clang while comment to attribute conversion happens and
792# https://github.com/ClangBuiltLinux/linux/issues/636 is discussed.
793KBUILD_CFLAGS += $(call cc-option,-Wimplicit-fallthrough,)
794endif
795
796# These warnings generated too much noise in a regular build.
797# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
798KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
799
800KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
801ifdef CONFIG_FRAME_POINTER
802KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls
803else
804# Some targets (ARM with Thumb2, for example), can't be built with frame
805# pointers. For those, we don't have FUNCTION_TRACER automatically
806# select FRAME_POINTER. However, FUNCTION_TRACER adds -pg, and this is
807# incompatible with -fomit-frame-pointer with current GCC, so we don't use
808# -fomit-frame-pointer with FUNCTION_TRACER.
809ifndef CONFIG_FUNCTION_TRACER
810KBUILD_CFLAGS += -fomit-frame-pointer
811endif
812endif
813
814# Initialize all stack variables with a 0xAA pattern.
815ifdef CONFIG_INIT_STACK_ALL_PATTERN
816KBUILD_CFLAGS += -ftrivial-auto-var-init=pattern
817endif
818
819# Initialize all stack variables with a zero value.
820ifdef CONFIG_INIT_STACK_ALL_ZERO
821# Future support for zero initialization is still being debated, see
822# https://bugs.llvm.org/show_bug.cgi?id=45497. These flags are subject to being
823# renamed or dropped.
824KBUILD_CFLAGS += -ftrivial-auto-var-init=zero
825KBUILD_CFLAGS += -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
826endif
827
828# While VLAs have been removed, GCC produces unreachable stack probes
829# for the randomize_kstack_offset feature. Disable it for all compilers.
830KBUILD_CFLAGS += $(call cc-option, -fno-stack-clash-protection)
831
832DEBUG_CFLAGS :=
833
834# Workaround for GCC versions < 5.0
835# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
836ifdef CONFIG_CC_IS_GCC
837DEBUG_CFLAGS += $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
838endif
839
840ifdef CONFIG_DEBUG_INFO
841
842ifdef CONFIG_DEBUG_INFO_SPLIT
843DEBUG_CFLAGS += -gsplit-dwarf
844else
845DEBUG_CFLAGS += -g
846endif
847
848ifneq ($(LLVM_IAS),1)
849KBUILD_AFLAGS += -Wa,-gdwarf-2
850endif
851
852ifndef CONFIG_DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
853dwarf-version-$(CONFIG_DEBUG_INFO_DWARF4) := 4
854dwarf-version-$(CONFIG_DEBUG_INFO_DWARF5) := 5
855DEBUG_CFLAGS += -gdwarf-$(dwarf-version-y)
856endif
857
858ifdef CONFIG_DEBUG_INFO_REDUCED
859DEBUG_CFLAGS += $(call cc-option, -femit-struct-debug-baseonly) \
860 $(call cc-option,-fno-var-tracking)
861endif
862
863ifdef CONFIG_DEBUG_INFO_COMPRESSED
864DEBUG_CFLAGS += -gz=zlib
865KBUILD_AFLAGS += -gz=zlib
866KBUILD_LDFLAGS += --compress-debug-sections=zlib
867endif
868
869endif # CONFIG_DEBUG_INFO
870
871KBUILD_CFLAGS += $(DEBUG_CFLAGS)
872export DEBUG_CFLAGS
873
874ifdef CONFIG_FUNCTION_TRACER
875ifdef CONFIG_FTRACE_MCOUNT_USE_CC
876 CC_FLAGS_FTRACE += -mrecord-mcount
877 ifdef CONFIG_HAVE_NOP_MCOUNT
878 ifeq ($(call cc-option-yn, -mnop-mcount),y)
879 CC_FLAGS_FTRACE += -mnop-mcount
880 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
881 endif
882 endif
883endif
884ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
885 CC_FLAGS_USING += -DCC_USING_NOP_MCOUNT
886endif
887ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
888 ifdef CONFIG_HAVE_C_RECORDMCOUNT
889 BUILD_C_RECORDMCOUNT := y
890 export BUILD_C_RECORDMCOUNT
891 endif
892endif
893ifdef CONFIG_HAVE_FENTRY
894 ifeq ($(call cc-option-yn, -mfentry),y)
895 CC_FLAGS_FTRACE += -mfentry
896 CC_FLAGS_USING += -DCC_USING_FENTRY
897 endif
898endif
899export CC_FLAGS_FTRACE
900KBUILD_CFLAGS += $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
901KBUILD_AFLAGS += $(CC_FLAGS_USING)
902endif
903
904# We trigger additional mismatches with less inlining
905ifdef CONFIG_DEBUG_SECTION_MISMATCH
906KBUILD_CFLAGS += $(call cc-option, -fno-inline-functions-called-once)
907endif
908
909ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
910KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
911LDFLAGS_vmlinux += --gc-sections
912endif
913
914ifdef CONFIG_SHADOW_CALL_STACK
915CC_FLAGS_SCS := -fsanitize=shadow-call-stack
916KBUILD_CFLAGS += $(CC_FLAGS_SCS)
917export CC_FLAGS_SCS
918endif
919
920ifdef CONFIG_LTO_CLANG
921ifdef CONFIG_LTO_CLANG_THIN
922CC_FLAGS_LTO := -flto=thin -fsplit-lto-unit
923KBUILD_LDFLAGS += --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
924else
925CC_FLAGS_LTO := -flto
926endif
927CC_FLAGS_LTO += -fvisibility=hidden
928
929# Limit inlining across translation units to reduce binary size
930KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
931endif
932
933ifdef CONFIG_LTO
934KBUILD_CFLAGS += -fno-lto $(CC_FLAGS_LTO)
935KBUILD_AFLAGS += -fno-lto
936export CC_FLAGS_LTO
937endif
938
939ifdef CONFIG_CFI_CLANG
940CC_FLAGS_CFI := -fsanitize=cfi \
941 -fsanitize-cfi-cross-dso \
942 -fno-sanitize-cfi-canonical-jump-tables \
943 -fno-sanitize-trap=cfi \
944 -fno-sanitize-blacklist
945
946ifdef CONFIG_CFI_PERMISSIVE
947CC_FLAGS_CFI += -fsanitize-recover=cfi
948endif
949
950# If LTO flags are filtered out, we must also filter out CFI.
951CC_FLAGS_LTO += $(CC_FLAGS_CFI)
952KBUILD_CFLAGS += $(CC_FLAGS_CFI)
953export CC_FLAGS_CFI
954endif
955
956ifdef CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_32B
957KBUILD_CFLAGS += -falign-functions=32
958endif
959
960# arch Makefile may override CC so keep this after arch Makefile is included
961NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include)
962
963# warn about C99 declaration after statement
964KBUILD_CFLAGS += -Wdeclaration-after-statement
965
966# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
967KBUILD_CFLAGS += -Wvla
968
969# disable pointer signed / unsigned warnings in gcc 4.0
970KBUILD_CFLAGS += -Wno-pointer-sign
971
972# disable stringop warnings in gcc 8+
973KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
974
975# We'll want to enable this eventually, but it's not going away for 5.7 at least
976KBUILD_CFLAGS += $(call cc-disable-warning, zero-length-bounds)
977KBUILD_CFLAGS += $(call cc-disable-warning, array-bounds)
978KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
979
980# Another good warning that we'll want to enable eventually
981KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
982
983# Enabled with W=2, disabled by default as noisy
984KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
985
986# disable invalid "can't wrap" optimizations for signed / pointers
987KBUILD_CFLAGS += -fno-strict-overflow
988
989# Make sure -fstack-check isn't enabled (like gentoo apparently did)
990KBUILD_CFLAGS += -fno-stack-check
991
992# conserve stack if available
993KBUILD_CFLAGS += $(call cc-option,-fconserve-stack)
994
995# Prohibit date/time macros, which would make the build non-deterministic
996KBUILD_CFLAGS += -Werror=date-time
997
998# enforce correct pointer usage
999KBUILD_CFLAGS += $(call cc-option,-Werror=incompatible-pointer-types)
1000
1001# Require designated initializers for all marked structures
1002KBUILD_CFLAGS += $(call cc-option,-Werror=designated-init)
1003
1004# change __FILE__ to the relative path from the srctree
1005KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1006
1007# include additional Makefiles when needed
1008include-y := scripts/Makefile.extrawarn
1009include-$(CONFIG_KASAN) += scripts/Makefile.kasan
1010include-$(CONFIG_KCSAN) += scripts/Makefile.kcsan
1011include-$(CONFIG_UBSAN) += scripts/Makefile.ubsan
1012include-$(CONFIG_KCOV) += scripts/Makefile.kcov
1013include-$(CONFIG_GCC_PLUGINS) += scripts/Makefile.gcc-plugins
1014
1015include $(addprefix $(srctree)/, $(include-y))
1016
1017# scripts/Makefile.gcc-plugins is intentionally included last.
1018# Do not add $(call cc-option,...) below this line. When you build the kernel
1019# from the clean source tree, the GCC plugins do not exist at this point.
1020
1021# Add user supplied CPPFLAGS, AFLAGS and CFLAGS as the last assignments
1022KBUILD_CPPFLAGS += $(KCPPFLAGS)
1023KBUILD_AFLAGS += $(KAFLAGS)
1024KBUILD_CFLAGS += $(KCFLAGS)
1025
1026KBUILD_LDFLAGS_MODULE += --build-id=sha1
1027LDFLAGS_vmlinux += --build-id=sha1
1028
1029ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1030LDFLAGS_vmlinux += $(call ld-option, -X,)
1031endif
1032
1033ifeq ($(CONFIG_RELR),y)
1034LDFLAGS_vmlinux += --pack-dyn-relocs=relr
1035endif
1036
1037# We never want expected sections to be placed heuristically by the
1038# linker. All sections should be explicitly named in the linker script.
1039ifdef CONFIG_LD_ORPHAN_WARN
1040LDFLAGS_vmlinux += --orphan-handling=warn
1041endif
1042
1043# Align the bit size of userspace programs with the kernel
1044KBUILD_USERCFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1045KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1046
1047# make the checker run with the right architecture
1048CHECKFLAGS += --arch=$(ARCH)
1049
1050# insure the checker run with the right endianness
1051CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1052
1053# the checker needs the correct machine size
1054CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1055
1056# Default kernel image to build when no specific target is given.
1057# KBUILD_IMAGE may be overruled on the command line or
1058# set in the environment
1059# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1060# this default value
1061export KBUILD_IMAGE ?= vmlinux
1062
1063#
1064# INSTALL_PATH specifies where to place the updated kernel and system map
1065# images. Default is /boot, but you can set it to other values
1066export INSTALL_PATH ?= /boot
1067
1068#
1069# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1070# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1071# an argument if needed. Otherwise it defaults to the kernel install path
1072#
1073export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1074
1075#
1076# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1077# relocations required by build roots. This is not defined in the
1078# makefile but the argument can be passed to make if needed.
1079#
1080
1081MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1082export MODLIB
1083
1084HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf)
1085
1086has_libelf = $(call try-run,\
1087 echo "int main() {}" | $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0)
1088
1089ifdef CONFIG_STACK_VALIDATION
1090 ifeq ($(has_libelf),1)
1091 objtool_target := tools/objtool FORCE
1092 else
1093 SKIP_STACK_VALIDATION := 1
1094 export SKIP_STACK_VALIDATION
1095 endif
1096endif
1097
1098PHONY += resolve_btfids_clean
1099
1100resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1101
1102# tools/bpf/resolve_btfids directory might not exist
1103# in output directory, skip its clean in that case
1104resolve_btfids_clean:
1105ifneq ($(wildcard $(resolve_btfids_O)),)
1106 $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1107endif
1108
1109ifdef CONFIG_BPF
1110ifdef CONFIG_DEBUG_INFO_BTF
1111 ifeq ($(has_libelf),1)
1112 resolve_btfids_target := tools/bpf/resolve_btfids FORCE
1113 else
1114 ERROR_RESOLVE_BTFIDS := 1
1115 endif
1116endif # CONFIG_DEBUG_INFO_BTF
1117endif # CONFIG_BPF
1118
1119PHONY += prepare0
1120
1121export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1122export MODORDER := $(extmod_prefix)modules.order
1123export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1124
1125ifeq ($(KBUILD_EXTMOD),)
1126core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
1127
1128vmlinux-dirs := $(patsubst %/,%,$(filter %/, \
1129 $(core-y) $(core-m) $(drivers-y) $(drivers-m) \
1130 $(libs-y) $(libs-m)))
1131
1132vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
1133 $(patsubst %/,%,$(filter %/, $(core-) \
1134 $(drivers-) $(libs-))))
1135
1136subdir-modorder := $(addsuffix modules.order,$(filter %/, \
1137 $(core-y) $(core-m) $(libs-y) $(libs-m) \
1138 $(drivers-y) $(drivers-m)))
1139
1140build-dirs := $(vmlinux-dirs)
1141clean-dirs := $(vmlinux-alldirs)
1142
1143# Externally visible symbols (used by link-vmlinux.sh)
1144KBUILD_VMLINUX_OBJS := $(head-y) $(patsubst %/,%/built-in.a, $(core-y))
1145KBUILD_VMLINUX_OBJS += $(addsuffix built-in.a, $(filter %/, $(libs-y)))
1146ifdef CONFIG_MODULES
1147KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1148KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1149else
1150KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1151endif
1152KBUILD_VMLINUX_OBJS += $(patsubst %/,%/built-in.a, $(drivers-y))
1153
1154export KBUILD_VMLINUX_OBJS KBUILD_VMLINUX_LIBS
1155export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
1156# used by scripts/Makefile.package
1157export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) LICENSES arch include scripts tools)
1158
1159vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
1160
1161# Recurse until adjust_autoksyms.sh is satisfied
1162PHONY += autoksyms_recursive
1163ifdef CONFIG_TRIM_UNUSED_KSYMS
1164# For the kernel to actually contain only the needed exported symbols,
1165# we have to build modules as well to determine what those symbols are.
1166# (this can be evaluated only once include/config/auto.conf has been included)
1167KBUILD_MODULES := 1
1168
1169autoksyms_recursive: descend modules.order
1170 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1171 "$(MAKE) -f $(srctree)/Makefile vmlinux"
1172endif
1173
1174autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1175
1176quiet_cmd_autoksyms_h = GEN $@
1177 cmd_autoksyms_h = mkdir -p $(dir $@); \
1178 $(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1179
1180$(autoksyms_h):
1181 $(call cmd,autoksyms_h)
1182
1183ARCH_POSTLINK := $(wildcard $(srctree)/arch/$(SRCARCH)/Makefile.postlink)
1184
1185# Final link of vmlinux with optional arch pass after final link
1186cmd_link-vmlinux = \
1187 $(CONFIG_SHELL) $< "$(LD)" "$(KBUILD_LDFLAGS)" "$(LDFLAGS_vmlinux)"; \
1188 $(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
1189
1190vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
1191 +$(call if_changed_dep,link-vmlinux)
1192
1193targets := vmlinux
1194
1195# The actual objects are generated when descending,
1196# make sure no implicit rule kicks in
1197$(sort $(vmlinux-deps) $(subdir-modorder)): descend ;
1198
1199filechk_kernel.release = \
1200 echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1201
1202# Store (new) KERNELRELEASE string in include/config/kernel.release
1203include/config/kernel.release: FORCE
1204 $(call filechk,kernel.release)
1205
1206# Additional helpers built in scripts/
1207# Carefully list dependencies so we do not try to build scripts twice
1208# in parallel
1209PHONY += scripts
1210scripts: scripts_basic scripts_dtc
1211 $(Q)$(MAKE) $(build)=$(@)
1212
1213# Things we need to do before we recursively start building the kernel
1214# or the modules are listed in "prepare".
1215# A multi level approach is used. prepareN is processed before prepareN-1.
1216# archprepare is used in arch Makefiles and when processed asm symlink,
1217# version.h and scripts_basic is processed / created.
1218
1219PHONY += prepare archprepare
1220
1221archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1222 asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1223 include/generated/autoconf.h remove-stale-files
1224
1225prepare0: archprepare
1226 $(Q)$(MAKE) $(build)=scripts/mod
1227 $(Q)$(MAKE) $(build)=.
1228
1229# All the preparing..
1230prepare: prepare0 prepare-objtool prepare-resolve_btfids
1231
1232PHONY += remove-stale-files
1233remove-stale-files:
1234 $(Q)$(srctree)/scripts/remove-stale-files
1235
1236# Support for using generic headers in asm-generic
1237asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1238
1239PHONY += asm-generic uapi-asm-generic
1240asm-generic: uapi-asm-generic
1241 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1242 generic=include/asm-generic
1243uapi-asm-generic:
1244 $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1245 generic=include/uapi/asm-generic
1246
1247PHONY += prepare-objtool prepare-resolve_btfids
1248prepare-objtool: $(objtool_target)
1249ifeq ($(SKIP_STACK_VALIDATION),1)
1250ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
1251 @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1252 @false
1253endif
1254ifdef CONFIG_UNWINDER_ORC
1255 @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1256 @false
1257else
1258 @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1259endif
1260endif
1261
1262prepare-resolve_btfids: $(resolve_btfids_target)
1263ifeq ($(ERROR_RESOLVE_BTFIDS),1)
1264 @echo "error: Cannot resolve BTF IDs for CONFIG_DEBUG_INFO_BTF, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2
1265 @false
1266endif
1267# Generate some files
1268# ---------------------------------------------------------------------------
1269
1270# KERNELRELEASE can change from a few different places, meaning version.h
1271# needs to be updated, so this check is forced on all builds
1272
1273uts_len := 64
1274define filechk_utsrelease.h
1275 if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1276 echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2; \
1277 exit 1; \
1278 fi; \
1279 echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1280endef
1281
1282define filechk_version.h
1283 if [ $(SUBLEVEL) -gt 255 ]; then \
1284 echo \#define LINUX_VERSION_CODE $(shell \
1285 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1286 else \
1287 echo \#define LINUX_VERSION_CODE $(shell \
1288 expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1289 fi; \
1290 echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + \
1291 ((c) > 255 ? 255 : (c)))'; \
1292 echo \#define LINUX_VERSION_MAJOR $(VERSION); \
1293 echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL); \
1294 echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1295endef
1296
1297$(version_h): PATCHLEVEL := $(if $(PATCHLEVEL), $(PATCHLEVEL), 0)
1298$(version_h): SUBLEVEL := $(if $(SUBLEVEL), $(SUBLEVEL), 0)
1299$(version_h): FORCE
1300 $(call filechk,version.h)
1301
1302include/generated/utsrelease.h: include/config/kernel.release FORCE
1303 $(call filechk,utsrelease.h)
1304
1305PHONY += headerdep
1306headerdep:
1307 $(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1308 $(srctree)/scripts/headerdep.pl -I$(srctree)/include
1309
1310# ---------------------------------------------------------------------------
1311# Kernel headers
1312
1313#Default location for installed headers
1314export INSTALL_HDR_PATH = $(objtree)/usr
1315
1316quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1317 cmd_headers_install = \
1318 mkdir -p $(INSTALL_HDR_PATH); \
1319 rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1320 usr/include $(INSTALL_HDR_PATH)
1321
1322PHONY += headers_install
1323headers_install: headers
1324 $(call cmd,headers_install)
1325
1326PHONY += archheaders archscripts
1327
1328hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1329
1330PHONY += headers
1331headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1332 $(if $(wildcard $(srctree)/arch/$(SRCARCH)/include/uapi/asm/Kbuild),, \
1333 $(error Headers not exportable for the $(SRCARCH) architecture))
1334 $(Q)$(MAKE) $(hdr-inst)=include/uapi
1335 $(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1336
1337# Deprecated. It is no-op now.
1338PHONY += headers_check
1339headers_check:
1340 @echo >&2 "=================== WARNING ==================="
1341 @echo >&2 "Since Linux 5.5, 'make headers_check' is no-op,"
1342 @echo >&2 "and will be removed after Linux 5.15 release."
1343 @echo >&2 "Please remove headers_check from your scripts."
1344 @echo >&2 "==============================================="
1345
1346ifdef CONFIG_HEADERS_INSTALL
1347prepare: headers
1348endif
1349
1350PHONY += scripts_unifdef
1351scripts_unifdef: scripts_basic
1352 $(Q)$(MAKE) $(build)=scripts scripts/unifdef
1353
1354# ---------------------------------------------------------------------------
1355# Kernel selftest
1356
1357PHONY += kselftest
1358kselftest:
1359 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1360
1361kselftest-%: FORCE
1362 $(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1363
1364PHONY += kselftest-merge
1365kselftest-merge:
1366 $(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1367 $(Q)find $(srctree)/tools/testing/selftests -name config | \
1368 xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1369 $(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1370
1371# ---------------------------------------------------------------------------
1372# Devicetree files
1373
1374ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1375dtstree := arch/$(SRCARCH)/boot/dts
1376endif
1377
1378ifneq ($(dtstree),)
1379
1380%.dtb: include/config/kernel.release scripts_dtc
1381 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1382
1383%.dtbo: include/config/kernel.release scripts_dtc
1384 $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1385
1386PHONY += dtbs dtbs_install dtbs_check
1387dtbs: include/config/kernel.release scripts_dtc
1388 $(Q)$(MAKE) $(build)=$(dtstree)
1389
1390ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1391export CHECK_DTBS=y
1392dtbs: dt_binding_check
1393endif
1394
1395dtbs_check: dtbs
1396
1397dtbs_install:
1398 $(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1399
1400ifdef CONFIG_OF_EARLY_FLATTREE
1401all: dtbs
1402endif
1403
1404endif
1405
1406PHONY += scripts_dtc
1407scripts_dtc: scripts_basic
1408 $(Q)$(MAKE) $(build)=scripts/dtc
1409
1410ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1411export CHECK_DT_BINDING=y
1412endif
1413
1414PHONY += dt_binding_check
1415dt_binding_check: scripts_dtc
1416 $(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1417
1418# ---------------------------------------------------------------------------
1419# Modules
1420
1421ifdef CONFIG_MODULES
1422
1423# By default, build modules as well
1424
1425all: modules
1426
1427# When we're building modules with modversions, we need to consider
1428# the built-in objects during the descend as well, in order to
1429# make sure the checksums are up to date before we record them.
1430ifdef CONFIG_MODVERSIONS
1431 KBUILD_BUILTIN := 1
1432endif
1433
1434# Build modules
1435#
1436# A module can be listed more than once in obj-m resulting in
1437# duplicate lines in modules.order files. Those are removed
1438# using awk while concatenating to the final file.
1439
1440PHONY += modules
1441modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
1442
1443cmd_modules_order = $(AWK) '!x[$$0]++' $(real-prereqs) > $@
1444
1445modules.order: $(subdir-modorder) FORCE
1446 $(call if_changed,modules_order)
1447
1448targets += modules.order
1449
1450# Target to prepare building external modules
1451PHONY += modules_prepare
1452modules_prepare: prepare
1453 $(Q)$(MAKE) $(build)=scripts scripts/module.lds
1454
1455export modules_sign_only :=
1456
1457ifeq ($(CONFIG_MODULE_SIG),y)
1458PHONY += modules_sign
1459modules_sign: modules_install
1460 @:
1461
1462# modules_sign is a subset of modules_install.
1463# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1464ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1465modules_sign_only := y
1466endif
1467endif
1468
1469modinst_pre :=
1470ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1471modinst_pre := __modinst_pre
1472endif
1473
1474modules_install: $(modinst_pre)
1475PHONY += __modinst_pre
1476__modinst_pre:
1477 @rm -rf $(MODLIB)/kernel
1478 @rm -f $(MODLIB)/source
1479 @mkdir -p $(MODLIB)/kernel
1480 @ln -s $(abspath $(srctree)) $(MODLIB)/source
1481 @if [ ! $(objtree) -ef $(MODLIB)/build ]; then \
1482 rm -f $(MODLIB)/build ; \
1483 ln -s $(CURDIR) $(MODLIB)/build ; \
1484 fi
1485 @sed 's:^:kernel/:' modules.order > $(MODLIB)/modules.order
1486 @cp -f modules.builtin $(MODLIB)/
1487 @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1488
1489endif # CONFIG_MODULES
1490
1491###
1492# Cleaning is done on three levels.
1493# make clean Delete most generated files
1494# Leave enough to build external modules
1495# make mrproper Delete the current configuration, and all generated files
1496# make distclean Remove editor backup files, patch leftover files and the like
1497
1498# Directories & files removed with 'make clean'
1499CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1500 modules.builtin modules.builtin.modinfo modules.nsdeps \
1501 compile_commands.json .thinlto-cache
1502
1503# Directories & files removed with 'make mrproper'
1504MRPROPER_FILES += include/config include/generated \
1505 arch/$(SRCARCH)/include/generated .tmp_objdiff \
1506 debian snap tar-install \
1507 .config .config.old .version \
1508 Module.symvers \
1509 signing_key.pem signing_key.priv signing_key.x509 \
1510 x509.genkey extra_certificates signing_key.x509.keyid \
1511 signing_key.x509.signer vmlinux-gdb.py \
1512 *.spec
1513
1514# Directories & files removed with 'make distclean'
1515DISTCLEAN_FILES += tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
1516
1517# clean - Delete most, but leave enough to build external modules
1518#
1519clean: rm-files := $(CLEAN_FILES)
1520
1521PHONY += archclean vmlinuxclean
1522
1523vmlinuxclean:
1524 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1525 $(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1526
1527clean: archclean vmlinuxclean resolve_btfids_clean
1528
1529# mrproper - Delete all generated files, including .config
1530#
1531mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1532mrproper-dirs := $(addprefix _mrproper_,scripts)
1533
1534PHONY += $(mrproper-dirs) mrproper
1535$(mrproper-dirs):
1536 $(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1537
1538mrproper: clean $(mrproper-dirs)
1539 $(call cmd,rmfiles)
1540
1541# distclean
1542#
1543distclean: rm-files := $(wildcard $(DISTCLEAN_FILES))
1544
1545PHONY += distclean
1546
1547distclean: mrproper
1548 $(call cmd,rmfiles)
1549 @find . $(RCS_FIND_IGNORE) \
1550 \( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1551 -o -name '*.bak' -o -name '#*#' -o -name '*%' \
1552 -o -name 'core' \) \
1553 -type f -print | xargs rm -f
1554
1555
1556# Packaging of the kernel to various formats
1557# ---------------------------------------------------------------------------
1558
1559%src-pkg: FORCE
1560 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1561%pkg: include/config/kernel.release FORCE
1562 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1563
1564# Brief documentation of the typical targets used
1565# ---------------------------------------------------------------------------
1566
1567boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1568boards := $(sort $(notdir $(boards)))
1569board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1570board-dirs := $(sort $(notdir $(board-dirs:/=)))
1571
1572PHONY += help
1573help:
1574 @echo 'Cleaning targets:'
1575 @echo ' clean - Remove most generated files but keep the config and'
1576 @echo ' enough build support to build external modules'
1577 @echo ' mrproper - Remove all generated files + config + various backup files'
1578 @echo ' distclean - mrproper + remove editor backup and patch files'
1579 @echo ''
1580 @echo 'Configuration targets:'
1581 @$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1582 @echo ''
1583 @echo 'Other generic targets:'
1584 @echo ' all - Build all targets marked with [*]'
1585 @echo '* vmlinux - Build the bare kernel'
1586 @echo '* modules - Build all modules'
1587 @echo ' modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1588 @echo ' dir/ - Build all files in dir and below'
1589 @echo ' dir/file.[ois] - Build specified target only'
1590 @echo ' dir/file.ll - Build the LLVM assembly file'
1591 @echo ' (requires compiler support for LLVM assembly generation)'
1592 @echo ' dir/file.lst - Build specified mixed source/assembly target only'
1593 @echo ' (requires a recent binutils and recent build (System.map))'
1594 @echo ' dir/file.ko - Build module including final link'
1595 @echo ' modules_prepare - Set up for building external modules'
1596 @echo ' tags/TAGS - Generate tags file for editors'
1597 @echo ' cscope - Generate cscope index'
1598 @echo ' gtags - Generate GNU GLOBAL index'
1599 @echo ' kernelrelease - Output the release version string (use with make -s)'
1600 @echo ' kernelversion - Output the version stored in Makefile (use with make -s)'
1601 @echo ' image_name - Output the image name (use with make -s)'
1602 @echo ' headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1603 echo ' (default: $(INSTALL_HDR_PATH))'; \
1604 echo ''
1605 @echo 'Static analysers:'
1606 @echo ' checkstack - Generate a list of stack hogs'
1607 @echo ' versioncheck - Sanity check on version.h usage'
1608 @echo ' includecheck - Check for duplicate included header files'
1609 @echo ' export_report - List the usages of all exported symbols'
1610 @echo ' headerdep - Detect inclusion cycles in headers'
1611 @echo ' coccicheck - Check with Coccinelle'
1612 @echo ' clang-analyzer - Check with clang static analyzer'
1613 @echo ' clang-tidy - Check with clang-tidy'
1614 @echo ''
1615 @echo 'Tools:'
1616 @echo ' nsdeps - Generate missing symbol namespace dependencies'
1617 @echo ''
1618 @echo 'Kernel selftest:'
1619 @echo ' kselftest - Build and run kernel selftest'
1620 @echo ' Build, install, and boot kernel before'
1621 @echo ' running kselftest on it'
1622 @echo ' Run as root for full coverage'
1623 @echo ' kselftest-all - Build kernel selftest'
1624 @echo ' kselftest-install - Build and install kernel selftest'
1625 @echo ' kselftest-clean - Remove all generated kselftest files'
1626 @echo ' kselftest-merge - Merge all the config dependencies of'
1627 @echo ' kselftest to existing .config.'
1628 @echo ''
1629 @$(if $(dtstree), \
1630 echo 'Devicetree:'; \
1631 echo '* dtbs - Build device tree blobs for enabled boards'; \
1632 echo ' dtbs_install - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1633 echo ' dt_binding_check - Validate device tree binding documents'; \
1634 echo ' dtbs_check - Validate device tree source files';\
1635 echo '')
1636
1637 @echo 'Userspace tools targets:'
1638 @echo ' use "make tools/help"'
1639 @echo ' or "cd tools; make help"'
1640 @echo ''
1641 @echo 'Kernel packaging:'
1642 @$(MAKE) -f $(srctree)/scripts/Makefile.package help
1643 @echo ''
1644 @echo 'Documentation targets:'
1645 @$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1646 @echo ''
1647 @echo 'Architecture specific targets ($(SRCARCH)):'
1648 @$(if $(archhelp),$(archhelp),\
1649 echo ' No architecture specific help defined for $(SRCARCH)')
1650 @echo ''
1651 @$(if $(boards), \
1652 $(foreach b, $(boards), \
1653 printf " %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1654 echo '')
1655 @$(if $(board-dirs), \
1656 $(foreach b, $(board-dirs), \
1657 printf " %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1658 printf " %-16s - Show all of the above\\n" help-boards; \
1659 echo '')
1660
1661 @echo ' make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1662 @echo ' make V=2 [targets] 2 => give reason for rebuild of target'
1663 @echo ' make O=dir [targets] Locate all output files in "dir", including .config'
1664 @echo ' make C=1 [targets] Check re-compiled c source with $$CHECK'
1665 @echo ' (sparse by default)'
1666 @echo ' make C=2 [targets] Force check of all c source with $$CHECK'
1667 @echo ' make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1668 @echo ' make W=n [targets] Enable extra build checks, n=1,2,3 where'
1669 @echo ' 1: warnings which may be relevant and do not occur too often'
1670 @echo ' 2: warnings which occur quite often but may still be relevant'
1671 @echo ' 3: more obscure warnings, can most likely be ignored'
1672 @echo ' Multiple levels can be combined with W=12 or W=123'
1673 @echo ''
1674 @echo 'Execute "make" or "make all" to build all targets marked with [*] '
1675 @echo 'For further info see the ./README file'
1676
1677
1678help-board-dirs := $(addprefix help-,$(board-dirs))
1679
1680help-boards: $(help-board-dirs)
1681
1682boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1683
1684$(help-board-dirs): help-%:
1685 @echo 'Architecture specific targets ($(SRCARCH) $*):'
1686 @$(if $(boards-per-dir), \
1687 $(foreach b, $(boards-per-dir), \
1688 printf " %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1689 echo '')
1690
1691
1692# Documentation targets
1693# ---------------------------------------------------------------------------
1694DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1695 linkcheckdocs dochelp refcheckdocs
1696PHONY += $(DOC_TARGETS)
1697$(DOC_TARGETS):
1698 $(Q)$(MAKE) $(build)=Documentation $@
1699
1700# Misc
1701# ---------------------------------------------------------------------------
1702
1703PHONY += scripts_gdb
1704scripts_gdb: prepare0
1705 $(Q)$(MAKE) $(build)=scripts/gdb
1706 $(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1707
1708ifdef CONFIG_GDB_SCRIPTS
1709all: scripts_gdb
1710endif
1711
1712else # KBUILD_EXTMOD
1713
1714###
1715# External module support.
1716# When building external modules the kernel used as basis is considered
1717# read-only, and no consistency checks are made and the make
1718# system is not used on the basis kernel. If updates are required
1719# in the basis kernel ordinary make commands (without M=...) must
1720# be used.
1721#
1722# The following are the only valid targets when building external
1723# modules.
1724# make M=dir clean Delete all automatically generated files
1725# make M=dir modules Make all modules in specified dir
1726# make M=dir Same as 'make M=dir modules'
1727# make M=dir modules_install
1728# Install the modules built in the module directory
1729# Assumes install directory is already created
1730
1731# We are always building only modules.
1732KBUILD_BUILTIN :=
1733KBUILD_MODULES := 1
1734
1735build-dirs := $(KBUILD_EXTMOD)
1736$(MODORDER): descend
1737 @:
1738
1739compile_commands.json: $(extmod_prefix)compile_commands.json
1740PHONY += compile_commands.json
1741
1742clean-dirs := $(KBUILD_EXTMOD)
1743clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1744 $(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1745
1746PHONY += help
1747help:
1748 @echo ' Building external modules.'
1749 @echo ' Syntax: make -C path/to/kernel/src M=$$PWD target'
1750 @echo ''
1751 @echo ' modules - default target, build the module(s)'
1752 @echo ' modules_install - install the module'
1753 @echo ' clean - remove generated files in module directory only'
1754 @echo ''
1755
1756# no-op for external module builds
1757PHONY += prepare modules_prepare
1758
1759endif # KBUILD_EXTMOD
1760
1761# ---------------------------------------------------------------------------
1762# Modules
1763
1764PHONY += modules modules_install
1765
1766ifdef CONFIG_MODULES
1767
1768modules: modules_check
1769 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1770
1771PHONY += modules_check
1772modules_check: $(MODORDER)
1773 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1774
1775quiet_cmd_depmod = DEPMOD $(MODLIB)
1776 cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1777 $(KERNELRELEASE)
1778
1779modules_install:
1780 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1781 $(call cmd,depmod)
1782
1783else # CONFIG_MODULES
1784
1785# Modules not configured
1786# ---------------------------------------------------------------------------
1787
1788modules modules_install:
1789 @echo >&2 '***'
1790 @echo >&2 '*** The present kernel configuration has modules disabled.'
1791 @echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1792 @echo >&2 '*** to enable CONFIG_MODULES.'
1793 @echo >&2 '***'
1794 @exit 1
1795
1796endif # CONFIG_MODULES
1797
1798# Single targets
1799# ---------------------------------------------------------------------------
1800# To build individual files in subdirectories, you can do like this:
1801#
1802# make foo/bar/baz.s
1803#
1804# The supported suffixes for single-target are listed in 'single-targets'
1805#
1806# To build only under specific subdirectories, you can do like this:
1807#
1808# make foo/bar/baz/
1809
1810ifdef single-build
1811
1812# .ko is special because modpost is needed
1813single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1814single-no-ko := $(sort $(patsubst %.ko,%.mod, $(MAKECMDGOALS)))
1815
1816$(single-ko): single_modpost
1817 @:
1818$(single-no-ko): descend
1819 @:
1820
1821ifeq ($(KBUILD_EXTMOD),)
1822# For the single build of in-tree modules, use a temporary file to avoid
1823# the situation of modules_install installing an invalid modules.order.
1824MODORDER := .modules.tmp
1825endif
1826
1827PHONY += single_modpost
1828single_modpost: $(single-no-ko) modules_prepare
1829 $(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1830 $(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1831
1832KBUILD_MODULES := 1
1833
1834export KBUILD_SINGLE_TARGETS := $(addprefix $(extmod_prefix), $(single-no-ko))
1835
1836# trim unrelated directories
1837build-dirs := $(foreach d, $(build-dirs), \
1838 $(if $(filter $(d)/%, $(KBUILD_SINGLE_TARGETS)), $(d)))
1839
1840endif
1841
1842ifndef CONFIG_MODULES
1843KBUILD_MODULES :=
1844endif
1845
1846# Handle descending into subdirectories listed in $(build-dirs)
1847# Preset locale variables to speed up the build process. Limit locale
1848# tweaks to this spot to avoid wrong language settings when running
1849# make menuconfig etc.
1850# Error messages still appears in the original language
1851PHONY += descend $(build-dirs)
1852descend: $(build-dirs)
1853$(build-dirs): prepare
1854 $(Q)$(MAKE) $(build)=$@ \
1855 single-build=$(if $(filter-out $@/, $(filter $@/%, $(KBUILD_SINGLE_TARGETS))),1) \
1856 need-builtin=1 need-modorder=1
1857
1858clean-dirs := $(addprefix _clean_, $(clean-dirs))
1859PHONY += $(clean-dirs) clean
1860$(clean-dirs):
1861 $(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1862
1863clean: $(clean-dirs)
1864 $(call cmd,rmfiles)
1865 @find $(if $(KBUILD_EXTMOD), $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
1866 \( -name '*.[aios]' -o -name '*.ko' -o -name '.*.cmd' \
1867 -o -name '*.ko.*' \
1868 -o -name '*.dtb' -o -name '*.dtbo' -o -name '*.dtb.S' -o -name '*.dt.yaml' \
1869 -o -name '*.dwo' -o -name '*.lst' \
1870 -o -name '*.su' -o -name '*.mod' \
1871 -o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
1872 -o -name '*.lex.c' -o -name '*.tab.[ch]' \
1873 -o -name '*.asn1.[ch]' \
1874 -o -name '*.symtypes' -o -name 'modules.order' \
1875 -o -name '.tmp_*.o.*' \
1876 -o -name '*.c.[012]*.*' \
1877 -o -name '*.ll' \
1878 -o -name '*.gcno' \
1879 -o -name '*.*.symversions' \) -type f -print | xargs rm -f
1880
1881# Generate tags for editors
1882# ---------------------------------------------------------------------------
1883quiet_cmd_tags = GEN $@
1884 cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
1885
1886tags TAGS cscope gtags: FORCE
1887 $(call cmd,tags)
1888
1889# Script to generate missing namespace dependencies
1890# ---------------------------------------------------------------------------
1891
1892PHONY += nsdeps
1893nsdeps: export KBUILD_NSDEPS=1
1894nsdeps: modules
1895 $(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
1896
1897# Clang Tooling
1898# ---------------------------------------------------------------------------
1899
1900quiet_cmd_gen_compile_commands = GEN $@
1901 cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
1902
1903$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
1904 $(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
1905 $(if $(CONFIG_MODULES), $(MODORDER)) FORCE
1906 $(call if_changed,gen_compile_commands)
1907
1908targets += $(extmod_prefix)compile_commands.json
1909
1910PHONY += clang-tidy clang-analyzer
1911
1912ifdef CONFIG_CC_IS_CLANG
1913quiet_cmd_clang_tools = CHECK $<
1914 cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
1915
1916clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
1917 $(call cmd,clang_tools)
1918else
1919clang-tidy clang-analyzer:
1920 @echo "$@ requires CC=clang" >&2
1921 @false
1922endif
1923
1924# Scripts to check various things for consistency
1925# ---------------------------------------------------------------------------
1926
1927PHONY += includecheck versioncheck coccicheck export_report
1928
1929includecheck:
1930 find $(srctree)/* $(RCS_FIND_IGNORE) \
1931 -name '*.[hcS]' -type f -print | sort \
1932 | xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
1933
1934versioncheck:
1935 find $(srctree)/* $(RCS_FIND_IGNORE) \
1936 -name '*.[hcS]' -type f -print | sort \
1937 | xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
1938
1939coccicheck:
1940 $(Q)$(BASH) $(srctree)/scripts/$@
1941
1942export_report:
1943 $(PERL) $(srctree)/scripts/export_report.pl
1944
1945PHONY += checkstack kernelrelease kernelversion image_name
1946
1947# UML needs a little special treatment here. It wants to use the host
1948# toolchain, so needs $(SUBARCH) passed to checkstack.pl. Everyone
1949# else wants $(ARCH), including people doing cross-builds, which means
1950# that $(SUBARCH) doesn't work here.
1951ifeq ($(ARCH), um)
1952CHECKSTACK_ARCH := $(SUBARCH)
1953else
1954CHECKSTACK_ARCH := $(ARCH)
1955endif
1956checkstack:
1957 $(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
1958 $(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
1959
1960kernelrelease:
1961 @echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1962
1963kernelversion:
1964 @echo $(KERNELVERSION)
1965
1966image_name:
1967 @echo $(KBUILD_IMAGE)
1968
1969# Clear a bunch of variables before executing the submake
1970
1971ifeq ($(quiet),silent_)
1972tools_silent=s
1973endif
1974
1975tools/: FORCE
1976 $(Q)mkdir -p $(objtree)/tools
1977 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1978
1979tools/%: FORCE
1980 $(Q)mkdir -p $(objtree)/tools
1981 $(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1982
1983quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN $(wildcard $(rm-files)))
1984 cmd_rmfiles = rm -rf $(rm-files)
1985
1986# read saved command lines for existing targets
1987existing-targets := $(wildcard $(sort $(targets)))
1988
1989-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
1990
1991endif # config-build
1992endif # mixed-build
1993endif # need-sub-make
1994
1995PHONY += FORCE
1996FORCE:
1997
1998# Declare the contents of the PHONY variable as phony. We keep that
1999# information in a variable so we can use it in if_changed and friends.
2000.PHONY: $(PHONY)