xref: /linux/Makefile (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 13
4SUBLEVEL = 0
5EXTRAVERSION = -rc1
6NAME = Baby Opossum Posse
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
14ifeq ($(filter output-sync,$(.FEATURES)),)
15$(error GNU Make >= 4.0 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41this-makefile := $(lastword $(MAKEFILE_LIST))
42abs_srctree := $(realpath $(dir $(this-makefile)))
43abs_output := $(CURDIR)
44
45ifneq ($(sub_make_done),1)
46
47# Do not use make's built-in rules and variables
48# (this increases performance and avoids hard-to-debug behaviour)
49MAKEFLAGS += -rR
50
51# Avoid funny character set dependencies
52unexport LC_ALL
53LC_COLLATE=C
54LC_NUMERIC=C
55export LC_COLLATE LC_NUMERIC
56
57# Avoid interference with shell env settings
58unexport GREP_OPTIONS
59
60# Beautify output
61# ---------------------------------------------------------------------------
62#
63# Most of build commands in Kbuild start with "cmd_". You can optionally define
64# "quiet_cmd_*". If defined, the short log is printed. Otherwise, no log from
65# that command is printed by default.
66#
67# e.g.)
68#    quiet_cmd_depmod = DEPMOD  $(MODLIB)
69#          cmd_depmod = $(srctree)/scripts/depmod.sh $(DEPMOD) $(KERNELRELEASE)
70#
71# A simple variant is to prefix commands with $(Q) - that's useful
72# for commands that shall be hidden in non-verbose mode.
73#
74#    $(Q)$(MAKE) $(build)=scripts/basic
75#
76# If KBUILD_VERBOSE contains 1, the whole command is echoed.
77# If KBUILD_VERBOSE contains 2, the reason for rebuilding is printed.
78#
79# To put more focus on warnings, be less verbose as default
80# Use 'make V=1' to see the full commands
81
82ifeq ("$(origin V)", "command line")
83  KBUILD_VERBOSE = $(V)
84endif
85
86quiet = quiet_
87Q = @
88
89ifneq ($(findstring 1, $(KBUILD_VERBOSE)),)
90  quiet =
91  Q =
92endif
93
94# If the user is running make -s (silent mode), suppress echoing of
95# commands
96ifneq ($(findstring s,$(firstword -$(MAKEFLAGS))),)
97quiet=silent_
98override KBUILD_VERBOSE :=
99endif
100
101export quiet Q KBUILD_VERBOSE
102
103# Call a source code checker (by default, "sparse") as part of the
104# C compilation.
105#
106# Use 'make C=1' to enable checking of only re-compiled files.
107# Use 'make C=2' to enable checking of *all* source files, regardless
108# of whether they are re-compiled or not.
109#
110# See the file "Documentation/dev-tools/sparse.rst" for more details,
111# including where to get the "sparse" utility.
112
113ifeq ("$(origin C)", "command line")
114  KBUILD_CHECKSRC = $(C)
115endif
116ifndef KBUILD_CHECKSRC
117  KBUILD_CHECKSRC = 0
118endif
119
120export KBUILD_CHECKSRC
121
122# Enable "clippy" (a linter) as part of the Rust compilation.
123#
124# Use 'make CLIPPY=1' to enable it.
125ifeq ("$(origin CLIPPY)", "command line")
126  KBUILD_CLIPPY := $(CLIPPY)
127endif
128
129export KBUILD_CLIPPY
130
131# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
132# directory of external module to build. Setting M= takes precedence.
133ifeq ("$(origin M)", "command line")
134  KBUILD_EXTMOD := $(M)
135endif
136
137ifeq ("$(origin MO)", "command line")
138  KBUILD_EXTMOD_OUTPUT := $(MO)
139endif
140
141$(if $(word 2, $(KBUILD_EXTMOD)), \
142	$(error building multiple external modules is not supported))
143
144$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
145	$(error module directory path cannot contain '$x')))
146
147# Remove trailing slashes
148ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
149KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
150endif
151
152export KBUILD_EXTMOD
153
154# backward compatibility
155KBUILD_EXTRA_WARN ?= $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)
156
157ifeq ("$(origin W)", "command line")
158  KBUILD_EXTRA_WARN := $(W)
159endif
160
161export KBUILD_EXTRA_WARN
162
163# Kbuild will save output files in the current working directory.
164# This does not need to match to the root of the kernel source tree.
165#
166# For example, you can do this:
167#
168#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
169#
170# If you want to save output files in a different location, there are
171# two syntaxes to specify it.
172#
173# 1) O=
174# Use "make O=dir/to/store/output/files/"
175#
176# 2) Set KBUILD_OUTPUT
177# Set the environment variable KBUILD_OUTPUT to point to the output directory.
178# export KBUILD_OUTPUT=dir/to/store/output/files/; make
179#
180# The O= assignment takes precedence over the KBUILD_OUTPUT environment
181# variable.
182
183ifeq ("$(origin O)", "command line")
184  KBUILD_OUTPUT := $(O)
185endif
186
187ifdef KBUILD_EXTMOD
188    ifdef KBUILD_OUTPUT
189        objtree := $(realpath $(KBUILD_OUTPUT))
190        $(if $(objtree),,$(error specified kernel directory "$(KBUILD_OUTPUT)" does not exist))
191    else
192        objtree := $(abs_srctree)
193    endif
194    # If Make is invoked from the kernel directory (either kernel
195    # source directory or kernel build directory), external modules
196    # are built in $(KBUILD_EXTMOD) for backward compatibility,
197    # otherwise, built in the current directory.
198    output := $(or $(KBUILD_EXTMOD_OUTPUT),$(if $(filter $(CURDIR),$(objtree) $(abs_srctree)),$(KBUILD_EXTMOD)))
199    # KBUILD_EXTMOD might be a relative path. Remember its absolute path before
200    # Make changes the working directory.
201    srcroot := $(realpath $(KBUILD_EXTMOD))
202    $(if $(srcroot),,$(error specified external module directory "$(KBUILD_EXTMOD)" does not exist))
203else
204    objtree := .
205    output := $(KBUILD_OUTPUT)
206endif
207
208export objtree srcroot
209
210# Do we want to change the working directory?
211ifneq ($(output),)
212# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
213$(shell mkdir -p "$(output)")
214# $(realpath ...) resolves symlinks
215abs_output := $(realpath $(output))
216$(if $(abs_output),,$(error failed to create output directory "$(output)"))
217endif
218
219ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
220$(error source directory cannot contain spaces or colons)
221endif
222
223export sub_make_done := 1
224
225endif # sub_make_done
226
227ifeq ($(abs_output),$(CURDIR))
228# Suppress "Entering directory ..." if we are at the final work directory.
229no-print-directory := --no-print-directory
230else
231# Recursion to show "Entering directory ..."
232need-sub-make := 1
233endif
234
235ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
236# If --no-print-directory is unset, recurse once again to set it.
237# You may end up recursing into __sub-make twice. This is needed due to the
238# behavior change in GNU Make 4.4.1.
239need-sub-make := 1
240endif
241
242ifeq ($(need-sub-make),1)
243
244PHONY += $(MAKECMDGOALS) __sub-make
245
246$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
247	@:
248
249# Invoke a second make in the output directory, passing relevant variables
250__sub-make:
251	$(Q)$(MAKE) $(no-print-directory) -C $(abs_output) \
252	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
253
254else # need-sub-make
255
256# We process the rest of the Makefile if this is the final invocation of make
257
258ifndef KBUILD_EXTMOD
259srcroot := $(abs_srctree)
260endif
261
262ifeq ($(srcroot),$(CURDIR))
263building_out_of_srctree :=
264else
265export building_out_of_srctree := 1
266endif
267
268ifdef KBUILD_ABS_SRCTREE
269    # Do nothing. Use the absolute path.
270else ifeq ($(srcroot),$(CURDIR))
271    # Building in the source.
272    srcroot := .
273else ifeq ($(srcroot)/,$(dir $(CURDIR)))
274    # Building in a subdirectory of the source.
275    srcroot := ..
276endif
277
278export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot))
279
280ifdef building_out_of_srctree
281export VPATH := $(srcroot)
282else
283VPATH :=
284endif
285
286# To make sure we do not include .config for any of the *config targets
287# catch them early, and hand them over to scripts/kconfig/Makefile
288# It is allowed to specify more targets when calling make, including
289# mixing *config targets and build targets.
290# For example 'make oldconfig all'.
291# Detect when mixed targets is specified, and make a second invocation
292# of make so .config is not included in this case either (for *config).
293
294version_h := include/generated/uapi/linux/version.h
295
296clean-targets := %clean mrproper cleandocs
297no-dot-config-targets := $(clean-targets) \
298			 cscope gtags TAGS tags help% %docs check% coccicheck \
299			 $(version_h) headers headers_% archheaders archscripts \
300			 %asm-generic kernelversion %src-pkg dt_binding_check \
301			 outputmakefile rustavailable rustfmt rustfmtcheck
302no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
303			  image_name
304single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %/
305
306config-build	:=
307mixed-build	:=
308need-config	:= 1
309may-sync-config	:= 1
310single-build	:=
311
312ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
313    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
314        need-config :=
315    endif
316endif
317
318ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
319    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
320        may-sync-config :=
321    endif
322endif
323
324need-compiler := $(may-sync-config)
325
326ifneq ($(KBUILD_EXTMOD),)
327    may-sync-config :=
328endif
329
330ifeq ($(KBUILD_EXTMOD),)
331    ifneq ($(filter %config,$(MAKECMDGOALS)),)
332        config-build := 1
333        ifneq ($(words $(MAKECMDGOALS)),1)
334            mixed-build := 1
335        endif
336    endif
337endif
338
339# We cannot build single targets and the others at the same time
340ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
341    single-build := 1
342    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
343        mixed-build := 1
344    endif
345endif
346
347# For "make -j clean all", "make -j mrproper defconfig all", etc.
348ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
349    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
350        mixed-build := 1
351    endif
352endif
353
354# install and modules_install need also be processed one by one
355ifneq ($(filter install,$(MAKECMDGOALS)),)
356    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
357        mixed-build := 1
358    endif
359endif
360
361ifdef mixed-build
362# ===========================================================================
363# We're called with mixed targets (*config and build targets).
364# Handle them one by one.
365
366PHONY += $(MAKECMDGOALS) __build_one_by_one
367
368$(MAKECMDGOALS): __build_one_by_one
369	@:
370
371__build_one_by_one:
372	$(Q)set -e; \
373	for i in $(MAKECMDGOALS); do \
374		$(MAKE) -f $(srctree)/Makefile $$i; \
375	done
376
377else # !mixed-build
378
379include $(srctree)/scripts/Kbuild.include
380
381# Read KERNELRELEASE from include/config/kernel.release (if it exists)
382KERNELRELEASE = $(call read-file, $(objtree)/include/config/kernel.release)
383KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
384export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
385
386include $(srctree)/scripts/subarch.include
387
388# Cross compiling and selecting different set of gcc/bin-utils
389# ---------------------------------------------------------------------------
390#
391# When performing cross compilation for other architectures ARCH shall be set
392# to the target architecture. (See arch/* for the possibilities).
393# ARCH can be set during invocation of make:
394# make ARCH=arm64
395# Another way is to have ARCH set in the environment.
396# The default ARCH is the host where make is executed.
397
398# CROSS_COMPILE specify the prefix used for all executables used
399# during compilation. Only gcc and related bin-utils executables
400# are prefixed with $(CROSS_COMPILE).
401# CROSS_COMPILE can be set on the command line
402# make CROSS_COMPILE=aarch64-linux-gnu-
403# Alternatively CROSS_COMPILE can be set in the environment.
404# Default value for CROSS_COMPILE is not to prefix executables
405# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
406ARCH		?= $(SUBARCH)
407
408# Architecture as present in compile.h
409UTS_MACHINE 	:= $(ARCH)
410SRCARCH 	:= $(ARCH)
411
412# Additional ARCH settings for x86
413ifeq ($(ARCH),i386)
414        SRCARCH := x86
415endif
416ifeq ($(ARCH),x86_64)
417        SRCARCH := x86
418endif
419
420# Additional ARCH settings for sparc
421ifeq ($(ARCH),sparc32)
422       SRCARCH := sparc
423endif
424ifeq ($(ARCH),sparc64)
425       SRCARCH := sparc
426endif
427
428# Additional ARCH settings for parisc
429ifeq ($(ARCH),parisc64)
430       SRCARCH := parisc
431endif
432
433export cross_compiling :=
434ifneq ($(SRCARCH),$(SUBARCH))
435cross_compiling := 1
436endif
437
438KCONFIG_CONFIG	?= .config
439export KCONFIG_CONFIG
440
441# SHELL used by kbuild
442CONFIG_SHELL := sh
443
444HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
445HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
446HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
447
448ifneq ($(LLVM),)
449ifneq ($(filter %/,$(LLVM)),)
450LLVM_PREFIX := $(LLVM)
451else ifneq ($(filter -%,$(LLVM)),)
452LLVM_SUFFIX := $(LLVM)
453endif
454
455HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
456HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
457else
458HOSTCC	= gcc
459HOSTCXX	= g++
460endif
461HOSTRUSTC = rustc
462HOSTPKG_CONFIG	= pkg-config
463
464KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
465			 -O2 -fomit-frame-pointer -std=gnu11
466KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
467KBUILD_USERLDFLAGS := $(USERLDFLAGS)
468
469# These flags apply to all Rust code in the tree, including the kernel and
470# host programs.
471export rust_common_flags := --edition=2021 \
472			    -Zbinary_dep_depinfo=y \
473			    -Astable_features \
474			    -Dnon_ascii_idents \
475			    -Dunsafe_op_in_unsafe_fn \
476			    -Wmissing_docs \
477			    -Wrust_2018_idioms \
478			    -Wunreachable_pub \
479			    -Wclippy::all \
480			    -Wclippy::ignored_unit_patterns \
481			    -Wclippy::mut_mut \
482			    -Wclippy::needless_bitwise_bool \
483			    -Wclippy::needless_continue \
484			    -Aclippy::needless_lifetimes \
485			    -Wclippy::no_mangle_with_rust_abi \
486			    -Wclippy::undocumented_unsafe_blocks \
487			    -Wclippy::unnecessary_safety_comment \
488			    -Wclippy::unnecessary_safety_doc \
489			    -Wrustdoc::missing_crate_level_docs \
490			    -Wrustdoc::unescaped_backticks
491
492KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
493		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
494KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
495		       -I $(srctree)/scripts/include
496KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
497			-Zallow-features= $(HOSTRUSTFLAGS)
498KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
499KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
500
501# Make variables (CC, etc...)
502CPP		= $(CC) -E
503ifneq ($(LLVM),)
504CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
505LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
506AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
507NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
508OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
509OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
510READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
511STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
512else
513CC		= $(CROSS_COMPILE)gcc
514LD		= $(CROSS_COMPILE)ld
515AR		= $(CROSS_COMPILE)ar
516NM		= $(CROSS_COMPILE)nm
517OBJCOPY		= $(CROSS_COMPILE)objcopy
518OBJDUMP		= $(CROSS_COMPILE)objdump
519READELF		= $(CROSS_COMPILE)readelf
520STRIP		= $(CROSS_COMPILE)strip
521endif
522RUSTC		= rustc
523RUSTDOC		= rustdoc
524RUSTFMT		= rustfmt
525CLIPPY_DRIVER	= clippy-driver
526BINDGEN		= bindgen
527PAHOLE		= pahole
528RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
529LEX		= flex
530YACC		= bison
531AWK		= awk
532INSTALLKERNEL  := installkernel
533PERL		= perl
534PYTHON3		= python3
535CHECK		= sparse
536BASH		= bash
537KGZIP		= gzip
538KBZIP2		= bzip2
539KLZOP		= lzop
540LZMA		= lzma
541LZ4		= lz4
542XZ		= xz
543ZSTD		= zstd
544
545CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
546		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
547NOSTDINC_FLAGS :=
548CFLAGS_MODULE   =
549RUSTFLAGS_MODULE =
550AFLAGS_MODULE   =
551LDFLAGS_MODULE  =
552CFLAGS_KERNEL	=
553RUSTFLAGS_KERNEL =
554AFLAGS_KERNEL	=
555LDFLAGS_vmlinux =
556
557# Use USERINCLUDE when you must reference the UAPI directories only.
558USERINCLUDE    := \
559		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
560		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
561		-I$(srctree)/include/uapi \
562		-I$(objtree)/include/generated/uapi \
563                -include $(srctree)/include/linux/compiler-version.h \
564                -include $(srctree)/include/linux/kconfig.h
565
566# Use LINUXINCLUDE when you must reference the include/ directory.
567# Needed to be compatible with the O= option
568LINUXINCLUDE    := \
569		-I$(srctree)/arch/$(SRCARCH)/include \
570		-I$(objtree)/arch/$(SRCARCH)/include/generated \
571		-I$(srctree)/include \
572		-I$(objtree)/include \
573		$(USERINCLUDE)
574
575KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
576
577KBUILD_CFLAGS :=
578KBUILD_CFLAGS += -std=gnu11
579KBUILD_CFLAGS += -fshort-wchar
580KBUILD_CFLAGS += -funsigned-char
581KBUILD_CFLAGS += -fno-common
582KBUILD_CFLAGS += -fno-PIE
583KBUILD_CFLAGS += -fno-strict-aliasing
584
585KBUILD_CPPFLAGS := -D__KERNEL__
586KBUILD_RUSTFLAGS := $(rust_common_flags) \
587		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
588		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
589		    -Csymbol-mangling-version=v0 \
590		    -Crelocation-model=static \
591		    -Zfunction-sections=n \
592		    -Wclippy::float_arithmetic
593
594KBUILD_AFLAGS_KERNEL :=
595KBUILD_CFLAGS_KERNEL :=
596KBUILD_RUSTFLAGS_KERNEL :=
597KBUILD_AFLAGS_MODULE  := -DMODULE
598KBUILD_CFLAGS_MODULE  := -DMODULE
599KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
600KBUILD_LDFLAGS_MODULE :=
601KBUILD_LDFLAGS :=
602CLANG_FLAGS :=
603
604ifeq ($(KBUILD_CLIPPY),1)
605	RUSTC_OR_CLIPPY_QUIET := CLIPPY
606	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
607else
608	RUSTC_OR_CLIPPY_QUIET := RUSTC
609	RUSTC_OR_CLIPPY = $(RUSTC)
610endif
611
612# Allows the usage of unstable features in stable compilers.
613export RUSTC_BOOTSTRAP := 1
614
615# Allows finding `.clippy.toml` in out-of-srctree builds.
616export CLIPPY_CONF_DIR := $(srctree)
617
618export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
619export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN
620export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
621export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
622export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
623export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
624export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
625export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
626
627export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
628export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
629export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
630export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
631export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
632export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
633
634# Files to ignore in find ... statements
635
636export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
637			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
638			  -prune -o
639
640# ===========================================================================
641# Rules shared between *config targets and build targets
642
643# Basic helpers built in scripts/basic/
644PHONY += scripts_basic
645scripts_basic:
646	$(Q)$(MAKE) $(build)=scripts/basic
647
648PHONY += outputmakefile
649ifdef building_out_of_srctree
650# Before starting out-of-tree build, make sure the source tree is clean.
651# outputmakefile generates a Makefile in the output directory, if using a
652# separate output directory. This allows convenient use of make in the
653# output directory.
654# At the same time when output Makefile generated, generate .gitignore to
655# ignore whole output directory
656
657ifdef KBUILD_EXTMOD
658print_env_for_makefile = \
659	echo "export KBUILD_OUTPUT = $(objtree)"; \
660	echo "export KBUILD_EXTMOD = $(realpath $(srcroot))" ; \
661	echo "export KBUILD_EXTMOD_OUTPUT = $(CURDIR)"
662else
663print_env_for_makefile = \
664	echo "export KBUILD_OUTPUT = $(CURDIR)"
665endif
666
667quiet_cmd_makefile = GEN     Makefile
668      cmd_makefile = { \
669	echo "\# Automatically generated by $(abs_srctree)/Makefile: don't edit"; \
670	$(print_env_for_makefile); \
671	echo "include $(abs_srctree)/Makefile"; \
672	} > Makefile
673
674outputmakefile:
675ifeq ($(KBUILD_EXTMOD),)
676	@if [ -f $(srctree)/.config -o \
677		 -d $(srctree)/include/config -o \
678		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
679		echo >&2 "***"; \
680		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
681		echo >&2 "*** in $(abs_srctree)";\
682		echo >&2 "***"; \
683		false; \
684	fi
685else
686	@if [ -f $(srcroot)/modules.order ]; then \
687		echo >&2 "***"; \
688		echo >&2 "*** The external module source tree is not clean."; \
689		echo >&2 "*** Please run 'make -C $(abs_srctree) M=$(realpath $(srcroot)) clean'"; \
690		echo >&2 "***"; \
691		false; \
692	fi
693endif
694	$(Q)ln -fsn $(srcroot) source
695	$(call cmd,makefile)
696	$(Q)test -e .gitignore || \
697	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
698endif
699
700# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
701# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
702# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they
703# need export), and from include/config/auto.conf.cmd to detect the compiler
704# upgrade.
705CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
706RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
707
708ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
709include $(srctree)/scripts/Makefile.clang
710endif
711
712# Include this also for config targets because some architectures need
713# cc-cross-prefix to determine CROSS_COMPILE.
714ifdef need-compiler
715include $(srctree)/scripts/Makefile.compiler
716endif
717
718ifdef config-build
719# ===========================================================================
720# *config targets only - make sure prerequisites are updated, and descend
721# in scripts/kconfig to make the *config target
722
723# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
724# KBUILD_DEFCONFIG may point out an alternative default configuration
725# used for 'make defconfig'
726include $(srctree)/arch/$(SRCARCH)/Makefile
727export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
728
729config: outputmakefile scripts_basic FORCE
730	$(Q)$(MAKE) $(build)=scripts/kconfig $@
731
732%config: outputmakefile scripts_basic FORCE
733	$(Q)$(MAKE) $(build)=scripts/kconfig $@
734
735else #!config-build
736# ===========================================================================
737# Build targets only - this includes vmlinux, arch-specific targets, clean
738# targets and others. In general all targets except *config targets.
739
740# If building an external module we do not care about the all: rule
741# but instead __all depend on modules
742PHONY += all
743ifeq ($(KBUILD_EXTMOD),)
744__all: all
745else
746__all: modules
747endif
748
749targets :=
750
751# Decide whether to build built-in, modular, or both.
752# Normally, just do built-in.
753
754KBUILD_MODULES :=
755KBUILD_BUILTIN := 1
756
757# If we have only "make modules", don't compile built-in objects.
758ifeq ($(MAKECMDGOALS),modules)
759  KBUILD_BUILTIN :=
760endif
761
762# If we have "make <whatever> modules", compile modules
763# in addition to whatever we do anyway.
764# Just "make" or "make all" shall build modules as well
765
766ifneq ($(filter all modules nsdeps compile_commands.json clang-%,$(MAKECMDGOALS)),)
767  KBUILD_MODULES := 1
768endif
769
770ifeq ($(MAKECMDGOALS),)
771  KBUILD_MODULES := 1
772endif
773
774export KBUILD_MODULES KBUILD_BUILTIN
775
776ifdef need-config
777include $(objtree)/include/config/auto.conf
778endif
779
780ifeq ($(KBUILD_EXTMOD),)
781# Objects we will link into vmlinux / subdirs we need to visit
782core-y		:=
783drivers-y	:=
784libs-y		:= lib/
785endif # KBUILD_EXTMOD
786
787# The all: target is the default when no target is given on the
788# command line.
789# This allow a user to issue only 'make' to build a kernel including modules
790# Defaults to vmlinux, but the arch makefile usually adds further targets
791all: vmlinux
792
793CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
794ifdef CONFIG_CC_IS_GCC
795CFLAGS_GCOV	+= -fno-tree-loop-im
796endif
797export CFLAGS_GCOV
798
799# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
800ifdef CONFIG_FUNCTION_TRACER
801  CC_FLAGS_FTRACE := -pg
802endif
803
804include $(srctree)/arch/$(SRCARCH)/Makefile
805
806ifdef need-config
807ifdef may-sync-config
808# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
809# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
810# because some architectures define CROSS_COMPILE there.
811include include/config/auto.conf.cmd
812
813$(KCONFIG_CONFIG):
814	@echo >&2 '***'
815	@echo >&2 '*** Configuration file "$@" not found!'
816	@echo >&2 '***'
817	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
818	@echo >&2 '*** "make menuconfig" or "make xconfig").'
819	@echo >&2 '***'
820	@/bin/false
821
822# The actual configuration files used during the build are stored in
823# include/generated/ and include/config/. Update them if .config is newer than
824# include/config/auto.conf (which mirrors .config).
825#
826# This exploits the 'multi-target pattern rule' trick.
827# The syncconfig should be executed only once to make all the targets.
828# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
829#
830# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
831# so you cannot notice that Kconfig is waiting for the user input.
832%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
833	$(Q)$(kecho) "  SYNC    $@"
834	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
835else # !may-sync-config
836# External modules and some install targets need include/generated/autoconf.h
837# and include/config/auto.conf but do not care if they are up-to-date.
838# Use auto.conf to show the error message
839
840checked-configs := $(addprefix $(objtree)/, include/generated/autoconf.h include/generated/rustc_cfg include/config/auto.conf)
841missing-configs := $(filter-out $(wildcard $(checked-configs)), $(checked-configs))
842
843ifdef missing-configs
844PHONY += $(objtree)/include/config/auto.conf
845
846$(objtree)/include/config/auto.conf:
847	@echo   >&2 '***'
848	@echo   >&2 '***  ERROR: Kernel configuration is invalid. The following files are missing:'
849	@printf >&2 '***    - %s\n' $(missing-configs)
850	@echo   >&2 '***  Run "make oldconfig && make prepare" on kernel source to fix it.'
851	@echo   >&2 '***'
852	@/bin/false
853endif
854
855endif # may-sync-config
856endif # need-config
857
858KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
859
860ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
861KBUILD_CFLAGS += -O2
862KBUILD_RUSTFLAGS += -Copt-level=2
863else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
864KBUILD_CFLAGS += -Os
865KBUILD_RUSTFLAGS += -Copt-level=s
866endif
867
868# Always set `debug-assertions` and `overflow-checks` because their default
869# depends on `opt-level` and `debug-assertions`, respectively.
870KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
871KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
872
873# Tell gcc to never replace conditional load with a non-conditional one
874ifdef CONFIG_CC_IS_GCC
875# gcc-10 renamed --param=allow-store-data-races=0 to
876# -fno-allow-store-data-races.
877KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
878KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
879endif
880
881ifdef CONFIG_READABLE_ASM
882# Disable optimizations that make assembler listings hard to read.
883# reorder blocks reorders the control in the function
884# ipa clone creates specialized cloned functions
885# partial inlining inlines only parts of functions
886KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
887endif
888
889stackp-flags-y                                    := -fno-stack-protector
890stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
891stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
892
893KBUILD_CFLAGS += $(stackp-flags-y)
894
895KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
896KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
897
898ifdef CONFIG_FRAME_POINTER
899KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
900KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
901else
902# Some targets (ARM with Thumb2, for example), can't be built with frame
903# pointers.  For those, we don't have FUNCTION_TRACER automatically
904# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
905# incompatible with -fomit-frame-pointer with current GCC, so we don't use
906# -fomit-frame-pointer with FUNCTION_TRACER.
907# In the Rust target specification, "frame-pointer" is set explicitly
908# to "may-omit".
909ifndef CONFIG_FUNCTION_TRACER
910KBUILD_CFLAGS	+= -fomit-frame-pointer
911endif
912endif
913
914# Initialize all stack variables with a 0xAA pattern.
915ifdef CONFIG_INIT_STACK_ALL_PATTERN
916KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
917endif
918
919# Initialize all stack variables with a zero value.
920ifdef CONFIG_INIT_STACK_ALL_ZERO
921KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
922ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
923# https://github.com/llvm/llvm-project/issues/44842
924CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
925export CC_AUTO_VAR_INIT_ZERO_ENABLER
926KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
927endif
928endif
929
930# While VLAs have been removed, GCC produces unreachable stack probes
931# for the randomize_kstack_offset feature. Disable it for all compilers.
932KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
933
934# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
935ifdef CONFIG_ZERO_CALL_USED_REGS
936KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
937endif
938
939ifdef CONFIG_FUNCTION_TRACER
940ifdef CONFIG_FTRACE_MCOUNT_USE_CC
941  CC_FLAGS_FTRACE	+= -mrecord-mcount
942  ifdef CONFIG_HAVE_NOP_MCOUNT
943    ifeq ($(call cc-option-yn, -mnop-mcount),y)
944      CC_FLAGS_FTRACE	+= -mnop-mcount
945      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
946    endif
947  endif
948endif
949ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
950  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
951    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
952  endif
953endif
954ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
955  ifdef CONFIG_HAVE_C_RECORDMCOUNT
956    BUILD_C_RECORDMCOUNT := y
957    export BUILD_C_RECORDMCOUNT
958  endif
959endif
960ifdef CONFIG_HAVE_FENTRY
961  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
962  ifeq ($(call cc-option-yn, -mfentry),y)
963    CC_FLAGS_FTRACE	+= -mfentry
964    CC_FLAGS_USING	+= -DCC_USING_FENTRY
965  endif
966endif
967export CC_FLAGS_FTRACE
968KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
969KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
970endif
971
972# We trigger additional mismatches with less inlining
973ifdef CONFIG_DEBUG_SECTION_MISMATCH
974KBUILD_CFLAGS += -fno-inline-functions-called-once
975endif
976
977# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
978ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
979KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
980KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
981LDFLAGS_vmlinux += --gc-sections
982endif
983
984ifdef CONFIG_SHADOW_CALL_STACK
985ifndef CONFIG_DYNAMIC_SCS
986CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
987KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
988KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack
989endif
990export CC_FLAGS_SCS
991endif
992
993ifdef CONFIG_LTO_CLANG
994ifdef CONFIG_LTO_CLANG_THIN
995CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
996else
997CC_FLAGS_LTO	:= -flto
998endif
999CC_FLAGS_LTO	+= -fvisibility=hidden
1000
1001# Limit inlining across translation units to reduce binary size
1002KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
1003endif
1004
1005ifdef CONFIG_LTO
1006KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
1007KBUILD_AFLAGS	+= -fno-lto
1008export CC_FLAGS_LTO
1009endif
1010
1011ifdef CONFIG_CFI_CLANG
1012CC_FLAGS_CFI	:= -fsanitize=kcfi
1013ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
1014	CC_FLAGS_CFI	+= -fsanitize-cfi-icall-experimental-normalize-integers
1015endif
1016ifdef CONFIG_RUST
1017	# Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects
1018	# CONFIG_CFI_ICALL_NORMALIZE_INTEGERS.
1019	RUSTC_FLAGS_CFI   := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers
1020	KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI)
1021	export RUSTC_FLAGS_CFI
1022endif
1023KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1024export CC_FLAGS_CFI
1025endif
1026
1027# Architectures can define flags to add/remove for floating-point support
1028CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
1029export CC_FLAGS_FPU
1030export CC_FLAGS_NO_FPU
1031
1032ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1033# Set the minimal function alignment. Use the newer GCC option
1034# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
1035# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
1036ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
1037KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
1038else
1039KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1040endif
1041endif
1042
1043# arch Makefile may override CC so keep this after arch Makefile is included
1044NOSTDINC_FLAGS += -nostdinc
1045
1046# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
1047# the kernel uses only C99 flexible arrays for dynamically sized trailing
1048# arrays. Enforce this for everything that may examine structure sizes and
1049# perform bounds checking.
1050KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
1051
1052#Currently, disable -Wstringop-overflow for GCC 11, globally.
1053KBUILD_CFLAGS-$(CONFIG_CC_NO_STRINGOP_OVERFLOW) += $(call cc-option, -Wno-stringop-overflow)
1054KBUILD_CFLAGS-$(CONFIG_CC_STRINGOP_OVERFLOW) += $(call cc-option, -Wstringop-overflow)
1055
1056# disable invalid "can't wrap" optimizations for signed / pointers
1057KBUILD_CFLAGS	+= -fno-strict-overflow
1058
1059# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1060KBUILD_CFLAGS  += -fno-stack-check
1061
1062# conserve stack if available
1063ifdef CONFIG_CC_IS_GCC
1064KBUILD_CFLAGS   += -fconserve-stack
1065endif
1066
1067# change __FILE__ to the relative path to the source directory
1068ifdef building_out_of_srctree
1069KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srcroot)/=)
1070endif
1071
1072# include additional Makefiles when needed
1073include-y			:= scripts/Makefile.extrawarn
1074include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1075include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1076include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1077include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1078include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1079include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1080include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1081include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1082include-$(CONFIG_AUTOFDO_CLANG)	+= scripts/Makefile.autofdo
1083include-$(CONFIG_PROPELLER_CLANG)	+= scripts/Makefile.propeller
1084include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1085
1086include $(addprefix $(srctree)/, $(include-y))
1087
1088# scripts/Makefile.gcc-plugins is intentionally included last.
1089# Do not add $(call cc-option,...) below this line. When you build the kernel
1090# from the clean source tree, the GCC plugins do not exist at this point.
1091
1092# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1093KBUILD_CPPFLAGS += $(KCPPFLAGS)
1094KBUILD_AFLAGS   += $(KAFLAGS)
1095KBUILD_CFLAGS   += $(KCFLAGS)
1096KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1097
1098KBUILD_LDFLAGS_MODULE += --build-id=sha1
1099LDFLAGS_vmlinux += --build-id=sha1
1100
1101KBUILD_LDFLAGS	+= -z noexecstack
1102ifeq ($(CONFIG_LD_IS_BFD),y)
1103KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1104endif
1105
1106ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1107LDFLAGS_vmlinux	+= -X
1108endif
1109
1110ifeq ($(CONFIG_RELR),y)
1111# ld.lld before 15 did not support -z pack-relative-relocs.
1112LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1113endif
1114
1115# We never want expected sections to be placed heuristically by the
1116# linker. All sections should be explicitly named in the linker script.
1117ifdef CONFIG_LD_ORPHAN_WARN
1118LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1119endif
1120
1121# Align the bit size of userspace programs with the kernel
1122KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1123KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1124
1125# make the checker run with the right architecture
1126CHECKFLAGS += --arch=$(ARCH)
1127
1128# insure the checker run with the right endianness
1129CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1130
1131# the checker needs the correct machine size
1132CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1133
1134# Default kernel image to build when no specific target is given.
1135# KBUILD_IMAGE may be overruled on the command line or
1136# set in the environment
1137# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1138# this default value
1139export KBUILD_IMAGE ?= vmlinux
1140
1141#
1142# INSTALL_PATH specifies where to place the updated kernel and system map
1143# images. Default is /boot, but you can set it to other values
1144export	INSTALL_PATH ?= /boot
1145
1146#
1147# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1148# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1149# an argument if needed. Otherwise it defaults to the kernel install path
1150#
1151export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1152
1153#
1154# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1155# relocations required by build roots.  This is not defined in the
1156# makefile but the argument can be passed to make if needed.
1157#
1158
1159MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1160export MODLIB
1161
1162PHONY += prepare0
1163
1164ifeq ($(KBUILD_EXTMOD),)
1165
1166build-dir	:= .
1167clean-dirs	:= $(sort . Documentation \
1168		     $(patsubst %/,%,$(filter %/, $(core-) \
1169			$(drivers-) $(libs-))))
1170
1171export ARCH_CORE	:= $(core-y)
1172export ARCH_LIB		:= $(filter %/, $(libs-y))
1173export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1174# Externally visible symbols (used by link-vmlinux.sh)
1175
1176KBUILD_VMLINUX_OBJS := ./built-in.a
1177ifdef CONFIG_MODULES
1178KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1179KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1180else
1181KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1182endif
1183
1184export KBUILD_VMLINUX_LIBS
1185export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1186
1187ifdef CONFIG_TRIM_UNUSED_KSYMS
1188# For the kernel to actually contain only the needed exported symbols,
1189# we have to build modules as well to determine what those symbols are.
1190KBUILD_MODULES := 1
1191endif
1192
1193# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1194quiet_cmd_ar_vmlinux.a = AR      $@
1195      cmd_ar_vmlinux.a = \
1196	rm -f $@; \
1197	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1198	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1199
1200targets += vmlinux.a
1201vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1202	$(call if_changed,ar_vmlinux.a)
1203
1204PHONY += vmlinux_o
1205vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1206	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1207
1208vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1209	@:
1210
1211PHONY += vmlinux
1212# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1213# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1214# unrelated; the decompressors just happen to have the same base name,
1215# arch/*/boot/compressed/vmlinux.
1216# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1217#
1218# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1219#   https://savannah.gnu.org/bugs/?61463
1220# For Make > 4.4, the following simple code will work:
1221#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1222vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1223vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1224vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1225	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1226
1227# The actual objects are generated when descending,
1228# make sure no implicit rule kicks in
1229$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1230
1231ifeq ($(origin KERNELRELEASE),file)
1232filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1233else
1234filechk_kernel.release = echo $(KERNELRELEASE)
1235endif
1236
1237# Store (new) KERNELRELEASE string in include/config/kernel.release
1238include/config/kernel.release: FORCE
1239	$(call filechk,kernel.release)
1240
1241# Additional helpers built in scripts/
1242# Carefully list dependencies so we do not try to build scripts twice
1243# in parallel
1244PHONY += scripts
1245scripts: scripts_basic scripts_dtc
1246	$(Q)$(MAKE) $(build)=$(@)
1247
1248# Things we need to do before we recursively start building the kernel
1249# or the modules are listed in "prepare".
1250# A multi level approach is used. prepareN is processed before prepareN-1.
1251# archprepare is used in arch Makefiles and when processed asm symlink,
1252# version.h and scripts_basic is processed / created.
1253
1254PHONY += prepare archprepare
1255
1256archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1257	asm-generic $(version_h) include/generated/utsrelease.h \
1258	include/generated/compile.h include/generated/autoconf.h \
1259	include/generated/rustc_cfg remove-stale-files
1260
1261prepare0: archprepare
1262	$(Q)$(MAKE) $(build)=scripts/mod
1263	$(Q)$(MAKE) $(build)=. prepare
1264
1265# All the preparing..
1266prepare: prepare0
1267ifdef CONFIG_RUST
1268	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1269	$(Q)$(MAKE) $(build)=rust
1270endif
1271
1272PHONY += remove-stale-files
1273remove-stale-files:
1274	$(Q)$(srctree)/scripts/remove-stale-files
1275
1276# Support for using generic headers in asm-generic
1277asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1278
1279PHONY += asm-generic uapi-asm-generic
1280asm-generic: uapi-asm-generic
1281	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1282	generic=include/asm-generic
1283uapi-asm-generic:
1284	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1285	generic=include/uapi/asm-generic
1286
1287# Generate some files
1288# ---------------------------------------------------------------------------
1289
1290# KERNELRELEASE can change from a few different places, meaning version.h
1291# needs to be updated, so this check is forced on all builds
1292
1293uts_len := 64
1294define filechk_utsrelease.h
1295	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1296	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1297	  exit 1;                                                         \
1298	fi;                                                               \
1299	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1300endef
1301
1302define filechk_version.h
1303	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1304		echo \#define LINUX_VERSION_CODE $(shell                 \
1305		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1306	else                                                             \
1307		echo \#define LINUX_VERSION_CODE $(shell                 \
1308		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1309	fi;                                                              \
1310	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1311	((c) > 255 ? 255 : (c)))';                                       \
1312	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1313	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1314	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1315endef
1316
1317$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1318$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1319$(version_h): FORCE
1320	$(call filechk,version.h)
1321
1322include/generated/utsrelease.h: include/config/kernel.release FORCE
1323	$(call filechk,utsrelease.h)
1324
1325filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1326	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1327
1328include/generated/compile.h: FORCE
1329	$(call filechk,compile.h)
1330
1331PHONY += headerdep
1332headerdep:
1333	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1334	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1335
1336# ---------------------------------------------------------------------------
1337# Kernel headers
1338
1339#Default location for installed headers
1340export INSTALL_HDR_PATH = $(objtree)/usr
1341
1342quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1343      cmd_headers_install = \
1344	mkdir -p $(INSTALL_HDR_PATH); \
1345	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1346	usr/include $(INSTALL_HDR_PATH)
1347
1348PHONY += headers_install
1349headers_install: headers
1350	$(call cmd,headers_install)
1351
1352PHONY += archheaders archscripts
1353
1354hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1355
1356PHONY += headers
1357headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1358	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1359	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1360	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1361
1362ifdef CONFIG_HEADERS_INSTALL
1363prepare: headers
1364endif
1365
1366PHONY += scripts_unifdef
1367scripts_unifdef: scripts_basic
1368	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1369
1370# ---------------------------------------------------------------------------
1371# Install
1372
1373# Many distributions have the custom install script, /sbin/installkernel.
1374# If DKMS is installed, 'make install' will eventually recurse back
1375# to this Makefile to build and install external modules.
1376# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1377
1378quiet_cmd_install = INSTALL $(INSTALL_PATH)
1379      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1380
1381# ---------------------------------------------------------------------------
1382# vDSO install
1383
1384PHONY += vdso_install
1385vdso_install: export INSTALL_FILES = $(vdso-install-y)
1386vdso_install:
1387	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1388
1389# ---------------------------------------------------------------------------
1390# Tools
1391
1392ifdef CONFIG_OBJTOOL
1393prepare: tools/objtool
1394endif
1395
1396ifdef CONFIG_BPF
1397ifdef CONFIG_DEBUG_INFO_BTF
1398prepare: tools/bpf/resolve_btfids
1399endif
1400endif
1401
1402# The tools build system is not a part of Kbuild and tends to introduce
1403# its own unique issues. If you need to integrate a new tool into Kbuild,
1404# please consider locating that tool outside the tools/ tree and using the
1405# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1406# here. See Documentation/kbuild/makefiles.rst for details.
1407
1408PHONY += resolve_btfids_clean
1409
1410resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1411
1412# tools/bpf/resolve_btfids directory might not exist
1413# in output directory, skip its clean in that case
1414resolve_btfids_clean:
1415ifneq ($(wildcard $(resolve_btfids_O)),)
1416	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1417endif
1418
1419# Clear a bunch of variables before executing the submake
1420ifeq ($(quiet),silent_)
1421tools_silent=s
1422endif
1423
1424tools/: FORCE
1425	$(Q)mkdir -p $(objtree)/tools
1426	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1427
1428tools/%: FORCE
1429	$(Q)mkdir -p $(objtree)/tools
1430	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1431
1432# ---------------------------------------------------------------------------
1433# Kernel selftest
1434
1435PHONY += kselftest
1436kselftest: headers
1437	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1438
1439kselftest-%: headers FORCE
1440	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1441
1442PHONY += kselftest-merge
1443kselftest-merge:
1444	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1445	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1446		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1447	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1448
1449# ---------------------------------------------------------------------------
1450# Devicetree files
1451
1452ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1453dtstree := arch/$(SRCARCH)/boot/dts
1454endif
1455
1456ifneq ($(dtstree),)
1457
1458%.dtb: dtbs_prepare
1459	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1460
1461%.dtbo: dtbs_prepare
1462	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1463
1464PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1465dtbs: dtbs_prepare
1466	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1467
1468# include/config/kernel.release is actually needed when installing DTBs because
1469# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1470# dtbs_install depend on it as dtbs_install may run as root.
1471dtbs_prepare: include/config/kernel.release scripts_dtc
1472
1473ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1474export CHECK_DTBS=y
1475endif
1476
1477ifneq ($(CHECK_DTBS),)
1478dtbs_prepare: dt_binding_schemas
1479endif
1480
1481dtbs_check: dtbs
1482
1483dtbs_install:
1484	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1485
1486ifdef CONFIG_OF_EARLY_FLATTREE
1487all: dtbs
1488endif
1489
1490ifdef CONFIG_GENERIC_BUILTIN_DTB
1491vmlinux: dtbs
1492endif
1493
1494endif
1495
1496PHONY += scripts_dtc
1497scripts_dtc: scripts_basic
1498	$(Q)$(MAKE) $(build)=scripts/dtc
1499
1500ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1501export CHECK_DTBS=y
1502endif
1503
1504PHONY += dt_binding_check dt_binding_schemas
1505dt_binding_check: dt_binding_schemas scripts_dtc
1506	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1507
1508dt_binding_schemas:
1509	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1510
1511PHONY += dt_compatible_check
1512dt_compatible_check: dt_binding_schemas
1513	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1514
1515# ---------------------------------------------------------------------------
1516# Modules
1517
1518ifdef CONFIG_MODULES
1519
1520# By default, build modules as well
1521
1522all: modules
1523
1524# When we're building modules with modversions, we need to consider
1525# the built-in objects during the descend as well, in order to
1526# make sure the checksums are up to date before we record them.
1527ifdef CONFIG_MODVERSIONS
1528  KBUILD_BUILTIN := 1
1529endif
1530
1531# Build modules
1532#
1533
1534# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1535# is an exception.
1536ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1537KBUILD_BUILTIN := 1
1538modules: vmlinux
1539endif
1540
1541modules: modules_prepare
1542
1543# Target to prepare building external modules
1544modules_prepare: prepare
1545	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1546
1547endif # CONFIG_MODULES
1548
1549###
1550# Cleaning is done on three levels.
1551# make clean     Delete most generated files
1552#                Leave enough to build external modules
1553# make mrproper  Delete the current configuration, and all generated files
1554# make distclean Remove editor backup files, patch leftover files and the like
1555
1556# Directories & files removed with 'make clean'
1557CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1558	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1559	       modules.builtin.ranges vmlinux.o.map \
1560	       compile_commands.json rust/test \
1561	       rust-project.json .vmlinux.objs .vmlinux.export.c \
1562               .builtin-dtbs-list .builtin-dtb.S
1563
1564# Directories & files removed with 'make mrproper'
1565MRPROPER_FILES += include/config include/generated          \
1566		  arch/$(SRCARCH)/include/generated .objdiff \
1567		  debian snap tar-install PKGBUILD pacman \
1568		  .config .config.old .version \
1569		  Module.symvers \
1570		  certs/signing_key.pem \
1571		  certs/x509.genkey \
1572		  vmlinux-gdb.py \
1573		  rpmbuild \
1574		  rust/libmacros.so
1575
1576# clean - Delete most, but leave enough to build external modules
1577#
1578clean: private rm-files := $(CLEAN_FILES)
1579
1580PHONY += archclean vmlinuxclean
1581
1582vmlinuxclean:
1583	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1584	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1585
1586clean: archclean vmlinuxclean resolve_btfids_clean
1587
1588# mrproper - Delete all generated files, including .config
1589#
1590mrproper: private rm-files := $(MRPROPER_FILES)
1591mrproper-dirs      := $(addprefix _mrproper_,scripts)
1592
1593PHONY += $(mrproper-dirs) mrproper
1594$(mrproper-dirs):
1595	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1596
1597mrproper: clean $(mrproper-dirs)
1598	$(call cmd,rmfiles)
1599	@find . $(RCS_FIND_IGNORE) \
1600		\( -name '*.rmeta' \) \
1601		-type f -print | xargs rm -f
1602
1603# distclean
1604#
1605PHONY += distclean
1606
1607distclean: mrproper
1608	@find . $(RCS_FIND_IGNORE) \
1609		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1610		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1611		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1612		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1613		-type f -print | xargs rm -f
1614
1615
1616# Packaging of the kernel to various formats
1617# ---------------------------------------------------------------------------
1618
1619%src-pkg: FORCE
1620	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1621%pkg: include/config/kernel.release FORCE
1622	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1623
1624# Brief documentation of the typical targets used
1625# ---------------------------------------------------------------------------
1626
1627boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1628boards := $(sort $(notdir $(boards)))
1629board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1630board-dirs := $(sort $(notdir $(board-dirs:/=)))
1631
1632PHONY += help
1633help:
1634	@echo  'Cleaning targets:'
1635	@echo  '  clean		  - Remove most generated files but keep the config and'
1636	@echo  '                    enough build support to build external modules'
1637	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1638	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1639	@echo  ''
1640	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1641	@echo  ''
1642	@echo  'Other generic targets:'
1643	@echo  '  all		  - Build all targets marked with [*]'
1644	@echo  '* vmlinux	  - Build the bare kernel'
1645	@echo  '* modules	  - Build all modules'
1646	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1647	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1648	@echo  '  dir/            - Build all files in dir and below'
1649	@echo  '  dir/file.[ois]  - Build specified target only'
1650	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1651	@echo  '                    (requires compiler support for LLVM assembly generation)'
1652	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1653	@echo  '                    (requires a recent binutils and recent build (System.map))'
1654	@echo  '  dir/file.ko     - Build module including final link'
1655	@echo  '  modules_prepare - Set up for building external modules'
1656	@echo  '  tags/TAGS	  - Generate tags file for editors'
1657	@echo  '  cscope	  - Generate cscope index'
1658	@echo  '  gtags           - Generate GNU GLOBAL index'
1659	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1660	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1661	@echo  '  image_name	  - Output the image name (use with make -s)'
1662	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1663	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1664	 echo  ''
1665	@echo  'Static analysers:'
1666	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1667	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1668	@echo  '  versioncheck    - Sanity check on version.h usage'
1669	@echo  '  includecheck    - Check for duplicate included header files'
1670	@echo  '  headerdep       - Detect inclusion cycles in headers'
1671	@echo  '  coccicheck      - Check with Coccinelle'
1672	@echo  '  clang-analyzer  - Check with clang static analyzer'
1673	@echo  '  clang-tidy      - Check with clang-tidy'
1674	@echo  ''
1675	@echo  'Tools:'
1676	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1677	@echo  ''
1678	@echo  'Kernel selftest:'
1679	@echo  '  kselftest         - Build and run kernel selftest'
1680	@echo  '                      Build, install, and boot kernel before'
1681	@echo  '                      running kselftest on it'
1682	@echo  '                      Run as root for full coverage'
1683	@echo  '  kselftest-all     - Build kernel selftest'
1684	@echo  '  kselftest-install - Build and install kernel selftest'
1685	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1686	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1687	@echo  '		      kselftest to existing .config.'
1688	@echo  ''
1689	@echo  'Rust targets:'
1690	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1691	@echo  '		    available and, if not, explains why.'
1692	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1693	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1694	@echo  '		    is formatted, printing a diff otherwise.'
1695	@echo  '  rustdoc	  - Generate Rust documentation'
1696	@echo  '		    (requires kernel .config)'
1697	@echo  '  rusttest        - Runs the Rust tests'
1698	@echo  '                    (requires kernel .config; downloads external repos)'
1699	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1700	@echo  '		    (requires kernel .config)'
1701	@echo  '  dir/file.[os]   - Build specified target only'
1702	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1703	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1704	@echo  '                    The output is not intended to be compilable.'
1705	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1706	@echo  ''
1707	@$(if $(dtstree), \
1708		echo 'Devicetree:'; \
1709		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1710		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1711		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1712		echo '  dt_binding_schemas - Build processed device tree binding schemas'; \
1713		echo '  dtbs_check         - Validate device tree source files';\
1714		echo '')
1715
1716	@echo 'Userspace tools targets:'
1717	@echo '  use "make tools/help"'
1718	@echo '  or  "cd tools; make help"'
1719	@echo  ''
1720	@echo  'Kernel packaging:'
1721	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1722	@echo  ''
1723	@echo  'Documentation targets:'
1724	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1725	@echo  ''
1726	@echo  'Architecture-specific targets ($(SRCARCH)):'
1727	@$(or $(archhelp),\
1728		echo '  No architecture-specific help defined for $(SRCARCH)')
1729	@echo  ''
1730	@$(if $(boards), \
1731		$(foreach b, $(boards), \
1732		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1733		echo '')
1734	@$(if $(board-dirs), \
1735		$(foreach b, $(board-dirs), \
1736		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1737		printf "  %-16s - Show all of the above\\n" help-boards; \
1738		echo '')
1739
1740	@echo  '  make V=n   [targets] 1: verbose build'
1741	@echo  '                       2: give reason for rebuild of target'
1742	@echo  '                       V=1 and V=2 can be combined with V=12'
1743	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1744	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1745	@echo  '                       (sparse by default)'
1746	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1747	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1748	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1749	@echo  '		1: warnings which may be relevant and do not occur too often'
1750	@echo  '		2: warnings which occur quite often but may still be relevant'
1751	@echo  '		3: more obscure warnings, can most likely be ignored'
1752	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1753	@echo  '		e: warnings are being treated as errors'
1754	@echo  '		Multiple levels can be combined with W=12 or W=123'
1755	@$(if $(dtstree), \
1756		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1757		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1758		)
1759	@echo  ''
1760	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1761	@echo  'For further info see the ./README file'
1762
1763
1764help-board-dirs := $(addprefix help-,$(board-dirs))
1765
1766help-boards: $(help-board-dirs)
1767
1768boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1769
1770$(help-board-dirs): help-%:
1771	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1772	@$(if $(boards-per-dir), \
1773		$(foreach b, $(boards-per-dir), \
1774		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1775		echo '')
1776
1777
1778# Documentation targets
1779# ---------------------------------------------------------------------------
1780DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1781	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1782PHONY += $(DOC_TARGETS)
1783$(DOC_TARGETS):
1784	$(Q)$(MAKE) $(build)=Documentation $@
1785
1786
1787# Rust targets
1788# ---------------------------------------------------------------------------
1789
1790# "Is Rust available?" target
1791PHONY += rustavailable
1792rustavailable:
1793	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1794
1795# Documentation target
1796#
1797# Using the singular to avoid running afoul of `no-dot-config-targets`.
1798PHONY += rustdoc
1799rustdoc: prepare
1800	$(Q)$(MAKE) $(build)=rust $@
1801
1802# Testing target
1803PHONY += rusttest
1804rusttest: prepare
1805	$(Q)$(MAKE) $(build)=rust $@
1806
1807# Formatting targets
1808PHONY += rustfmt rustfmtcheck
1809
1810rustfmt:
1811	$(Q)find $(srctree) $(RCS_FIND_IGNORE) \
1812		-type f -a -name '*.rs' -a ! -name '*generated*' -print \
1813		| xargs $(RUSTFMT) $(rustfmt_flags)
1814
1815rustfmtcheck: rustfmt_flags = --check
1816rustfmtcheck: rustfmt
1817
1818# Misc
1819# ---------------------------------------------------------------------------
1820
1821PHONY += misc-check
1822misc-check:
1823	$(Q)$(srctree)/scripts/misc-check
1824
1825all: misc-check
1826
1827PHONY += scripts_gdb
1828scripts_gdb: prepare0
1829	$(Q)$(MAKE) $(build)=scripts/gdb
1830	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1831
1832ifdef CONFIG_GDB_SCRIPTS
1833all: scripts_gdb
1834endif
1835
1836else # KBUILD_EXTMOD
1837
1838filechk_kernel.release = echo $(KERNELRELEASE)
1839
1840###
1841# External module support.
1842# When building external modules the kernel used as basis is considered
1843# read-only, and no consistency checks are made and the make
1844# system is not used on the basis kernel. If updates are required
1845# in the basis kernel ordinary make commands (without M=...) must be used.
1846
1847# We are always building only modules.
1848KBUILD_BUILTIN :=
1849KBUILD_MODULES := 1
1850
1851build-dir := .
1852
1853clean-dirs := .
1854clean: private rm-files := Module.symvers modules.nsdeps compile_commands.json
1855
1856PHONY += prepare
1857# now expand this into a simple variable to reduce the cost of shell evaluations
1858prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1859prepare:
1860	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1861		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1862		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1863		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1864	fi
1865
1866PHONY += help
1867help:
1868	@echo  '  Building external modules.'
1869	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1870	@echo  ''
1871	@echo  '  modules         - default target, build the module(s)'
1872	@echo  '  modules_install - install the module'
1873	@echo  '  clean           - remove generated files in module directory only'
1874	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1875	@echo  ''
1876
1877ifndef CONFIG_MODULES
1878modules modules_install: __external_modules_error
1879__external_modules_error:
1880	@echo >&2 '***'
1881	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1882	@echo >&2 '*** You cannot build or install external modules.'
1883	@echo >&2 '***'
1884	@false
1885endif
1886
1887endif # KBUILD_EXTMOD
1888
1889# ---------------------------------------------------------------------------
1890# Modules
1891
1892PHONY += modules modules_install modules_sign modules_prepare
1893
1894modules_install:
1895	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1896	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1897
1898ifeq ($(CONFIG_MODULE_SIG),y)
1899# modules_sign is a subset of modules_install.
1900# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1901modules_sign: modules_install
1902	@:
1903else
1904modules_sign:
1905	@echo >&2 '***'
1906	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1907	@echo >&2 '***'
1908	@false
1909endif
1910
1911ifdef CONFIG_MODULES
1912
1913modules.order: $(build-dir)
1914	@:
1915
1916# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1917# This is solely useful to speed up test compiles.
1918modules: modpost
1919ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1920	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1921endif
1922
1923PHONY += modules_check
1924modules_check: modules.order
1925	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1926
1927else # CONFIG_MODULES
1928
1929modules:
1930	@:
1931
1932KBUILD_MODULES :=
1933
1934endif # CONFIG_MODULES
1935
1936PHONY += modpost
1937modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1938	 $(if $(KBUILD_MODULES), modules_check)
1939	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1940
1941# Single targets
1942# ---------------------------------------------------------------------------
1943# To build individual files in subdirectories, you can do like this:
1944#
1945#   make foo/bar/baz.s
1946#
1947# The supported suffixes for single-target are listed in 'single-targets'
1948#
1949# To build only under specific subdirectories, you can do like this:
1950#
1951#   make foo/bar/baz/
1952
1953ifdef single-build
1954
1955# .ko is special because modpost is needed
1956single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1957single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1958		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1959
1960$(single-ko): single_modules
1961	@:
1962$(single-no-ko): $(build-dir)
1963	@:
1964
1965# Remove modules.order when done because it is not the real one.
1966PHONY += single_modules
1967single_modules: $(single-no-ko) modules_prepare
1968	$(Q){ $(foreach m, $(single-ko), echo $(m:%.ko=%.o);) } > modules.order
1969	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1970ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1971	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1972endif
1973	$(Q)rm -f modules.order
1974
1975single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1976
1977KBUILD_MODULES := 1
1978
1979endif
1980
1981prepare: outputmakefile
1982
1983# Preset locale variables to speed up the build process. Limit locale
1984# tweaks to this spot to avoid wrong language settings when running
1985# make menuconfig etc.
1986# Error messages still appears in the original language
1987PHONY += $(build-dir)
1988$(build-dir): prepare
1989	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
1990
1991clean-dirs := $(addprefix _clean_, $(clean-dirs))
1992PHONY += $(clean-dirs) clean
1993$(clean-dirs):
1994	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
1995
1996clean: $(clean-dirs)
1997	$(call cmd,rmfiles)
1998	@find . $(RCS_FIND_IGNORE) \
1999		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2000		-o -name '*.ko.*' \
2001		-o -name '*.dtb' -o -name '*.dtbo' \
2002		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2003		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
2004		-o -name '*.dwo' -o -name '*.lst' \
2005		-o -name '*.su' -o -name '*.mod' \
2006		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2007		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2008		-o -name '*.asn1.[ch]' \
2009		-o -name '*.symtypes' -o -name 'modules.order' \
2010		-o -name '*.c.[012]*.*' \
2011		-o -name '*.ll' \
2012		-o -name '*.gcno' \
2013		\) -type f -print \
2014		-o -name '.tmp_*' -print \
2015		| xargs rm -rf
2016
2017# Generate tags for editors
2018# ---------------------------------------------------------------------------
2019quiet_cmd_tags = GEN     $@
2020      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2021
2022tags TAGS cscope gtags: FORCE
2023	$(call cmd,tags)
2024
2025# Generate rust-project.json (a file that describes the structure of non-Cargo
2026# Rust projects) for rust-analyzer (an implementation of the Language Server
2027# Protocol).
2028PHONY += rust-analyzer
2029rust-analyzer:
2030	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
2031ifdef KBUILD_EXTMOD
2032# FIXME: external modules must not descend into a sub-directory of the kernel
2033	$(Q)$(MAKE) $(build)=$(objtree)/rust src=$(srctree)/rust $@
2034else
2035	$(Q)$(MAKE) $(build)=rust $@
2036endif
2037
2038# Script to generate missing namespace dependencies
2039# ---------------------------------------------------------------------------
2040
2041PHONY += nsdeps
2042nsdeps: export KBUILD_NSDEPS=1
2043nsdeps: modules
2044	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2045
2046# Clang Tooling
2047# ---------------------------------------------------------------------------
2048
2049quiet_cmd_gen_compile_commands = GEN     $@
2050      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2051
2052compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py \
2053	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2054	$(if $(CONFIG_MODULES), modules.order) FORCE
2055	$(call if_changed,gen_compile_commands)
2056
2057targets += compile_commands.json
2058
2059PHONY += clang-tidy clang-analyzer
2060
2061ifdef CONFIG_CC_IS_CLANG
2062quiet_cmd_clang_tools = CHECK   $<
2063      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2064
2065clang-tidy clang-analyzer: compile_commands.json
2066	$(call cmd,clang_tools)
2067else
2068clang-tidy clang-analyzer:
2069	@echo "$@ requires CC=clang" >&2
2070	@false
2071endif
2072
2073# Scripts to check various things for consistency
2074# ---------------------------------------------------------------------------
2075
2076PHONY += includecheck versioncheck coccicheck
2077
2078includecheck:
2079	find $(srctree)/* $(RCS_FIND_IGNORE) \
2080		-name '*.[hcS]' -type f -print | sort \
2081		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2082
2083versioncheck:
2084	find $(srctree)/* $(RCS_FIND_IGNORE) \
2085		-name '*.[hcS]' -type f -print | sort \
2086		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2087
2088coccicheck:
2089	$(Q)$(BASH) $(srctree)/scripts/$@
2090
2091PHONY += checkstack kernelrelease kernelversion image_name
2092
2093# UML needs a little special treatment here.  It wants to use the host
2094# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2095# else wants $(ARCH), including people doing cross-builds, which means
2096# that $(SUBARCH) doesn't work here.
2097ifeq ($(ARCH), um)
2098CHECKSTACK_ARCH := $(SUBARCH)
2099else
2100CHECKSTACK_ARCH := $(ARCH)
2101endif
2102MINSTACKSIZE	?= 100
2103checkstack:
2104	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2105	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2106
2107kernelrelease:
2108	@$(filechk_kernel.release)
2109
2110kernelversion:
2111	@echo $(KERNELVERSION)
2112
2113image_name:
2114	@echo $(KBUILD_IMAGE)
2115
2116PHONY += run-command
2117run-command:
2118	$(Q)$(KBUILD_RUN_COMMAND)
2119
2120quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2121      cmd_rmfiles = rm -rf $(rm-files)
2122
2123# read saved command lines for existing targets
2124existing-targets := $(wildcard $(sort $(targets)))
2125
2126-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2127
2128endif # config-build
2129endif # mixed-build
2130endif # need-sub-make
2131
2132PHONY += FORCE
2133FORCE:
2134
2135# Declare the contents of the PHONY variable as phony.  We keep that
2136# information in a variable so we can use it in if_changed and friends.
2137.PHONY: $(PHONY)
2138