1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 16
4SUBLEVEL = 0
5EXTRAVERSION = -rc3
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 $(KBUILD_EXTMOD).)
150endif
151
152export KBUILD_EXTMOD
153
154ifeq ("$(origin W)", "command line")
155  KBUILD_EXTRA_WARN := $(W)
156endif
157
158export KBUILD_EXTRA_WARN
159
160# Kbuild will save output files in the current working directory.
161# This does not need to match to the root of the kernel source tree.
162#
163# For example, you can do this:
164#
165#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
166#
167# If you want to save output files in a different location, there are
168# two syntaxes to specify it.
169#
170# 1) O=
171# Use "make O=dir/to/store/output/files/"
172#
173# 2) Set KBUILD_OUTPUT
174# Set the environment variable KBUILD_OUTPUT to point to the output directory.
175# export KBUILD_OUTPUT=dir/to/store/output/files/; make
176#
177# The O= assignment takes precedence over the KBUILD_OUTPUT environment
178# variable.
179
180ifeq ("$(origin O)", "command line")
181  KBUILD_OUTPUT := $(O)
182endif
183
184ifdef KBUILD_EXTMOD
185    ifdef KBUILD_OUTPUT
186        objtree := $(realpath $(KBUILD_OUTPUT))
187        $(if $(objtree),,$(error specified kernel directory "$(KBUILD_OUTPUT)" does not exist))
188    else
189        objtree := $(abs_srctree)
190    endif
191    # If Make is invoked from the kernel directory (either kernel
192    # source directory or kernel build directory), external modules
193    # are built in $(KBUILD_EXTMOD) for backward compatibility,
194    # otherwise, built in the current directory.
195    output := $(or $(KBUILD_EXTMOD_OUTPUT),$(if $(filter $(CURDIR),$(objtree) $(abs_srctree)),$(KBUILD_EXTMOD)))
196    # KBUILD_EXTMOD might be a relative path. Remember its absolute path before
197    # Make changes the working directory.
198    srcroot := $(realpath $(KBUILD_EXTMOD))
199    $(if $(srcroot),,$(error specified external module directory "$(KBUILD_EXTMOD)" does not exist))
200else
201    objtree := .
202    output := $(KBUILD_OUTPUT)
203endif
204
205export objtree srcroot
206
207# Do we want to change the working directory?
208ifneq ($(output),)
209# $(realpath ...) gets empty if the path does not exist. Run 'mkdir -p' first.
210$(shell mkdir -p "$(output)")
211# $(realpath ...) resolves symlinks
212abs_output := $(realpath $(output))
213$(if $(abs_output),,$(error failed to create output directory "$(output)"))
214endif
215
216ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
217$(error source directory cannot contain spaces or colons)
218endif
219
220export sub_make_done := 1
221
222endif # sub_make_done
223
224ifeq ($(abs_output),$(CURDIR))
225# Suppress "Entering directory ..." if we are at the final work directory.
226no-print-directory := --no-print-directory
227else
228# Recursion to show "Entering directory ..."
229need-sub-make := 1
230endif
231
232ifeq ($(filter --no-print-directory, $(MAKEFLAGS)),)
233# If --no-print-directory is unset, recurse once again to set it.
234# You may end up recursing into __sub-make twice. This is needed due to the
235# behavior change in GNU Make 4.4.1.
236need-sub-make := 1
237endif
238
239ifeq ($(need-sub-make),1)
240
241PHONY += $(MAKECMDGOALS) __sub-make
242
243$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
244	@:
245
246# Invoke a second make in the output directory, passing relevant variables
247__sub-make:
248	$(Q)$(MAKE) $(no-print-directory) -C $(abs_output) \
249	-f $(abs_srctree)/Makefile $(MAKECMDGOALS)
250
251else # need-sub-make
252
253# We process the rest of the Makefile if this is the final invocation of make
254
255ifndef KBUILD_EXTMOD
256srcroot := $(abs_srctree)
257endif
258
259ifeq ($(srcroot),$(CURDIR))
260building_out_of_srctree :=
261else
262export building_out_of_srctree := 1
263endif
264
265ifdef KBUILD_ABS_SRCTREE
266    # Do nothing. Use the absolute path.
267else ifeq ($(srcroot),$(CURDIR))
268    # Building in the source.
269    srcroot := .
270else ifeq ($(srcroot)/,$(dir $(CURDIR)))
271    # Building in a subdirectory of the source.
272    srcroot := ..
273endif
274
275export srctree := $(if $(KBUILD_EXTMOD),$(abs_srctree),$(srcroot))
276
277ifdef building_out_of_srctree
278export VPATH := $(srcroot)
279else
280VPATH :=
281endif
282
283# To make sure we do not include .config for any of the *config targets
284# catch them early, and hand them over to scripts/kconfig/Makefile
285# It is allowed to specify more targets when calling make, including
286# mixing *config targets and build targets.
287# For example 'make oldconfig all'.
288# Detect when mixed targets is specified, and make a second invocation
289# of make so .config is not included in this case either (for *config).
290
291version_h := include/generated/uapi/linux/version.h
292
293clean-targets := %clean mrproper cleandocs
294no-dot-config-targets := $(clean-targets) \
295			 cscope gtags TAGS tags help% %docs check% coccicheck \
296			 $(version_h) headers headers_% archheaders archscripts \
297			 %asm-generic kernelversion %src-pkg dt_binding_check \
298			 outputmakefile rustavailable rustfmt rustfmtcheck
299no-sync-config-targets := $(no-dot-config-targets) %install modules_sign kernelrelease \
300			  image_name
301single-targets := %.a %.i %.ko %.lds %.ll %.lst %.mod %.o %.rsi %.s %/
302
303config-build	:=
304mixed-build	:=
305need-config	:= 1
306may-sync-config	:= 1
307single-build	:=
308
309ifneq ($(filter $(no-dot-config-targets), $(MAKECMDGOALS)),)
310    ifeq ($(filter-out $(no-dot-config-targets), $(MAKECMDGOALS)),)
311        need-config :=
312    endif
313endif
314
315ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
316    ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
317        may-sync-config :=
318    endif
319endif
320
321need-compiler := $(may-sync-config)
322
323ifneq ($(KBUILD_EXTMOD),)
324    may-sync-config :=
325endif
326
327ifeq ($(KBUILD_EXTMOD),)
328    ifneq ($(filter %config,$(MAKECMDGOALS)),)
329        config-build := 1
330        ifneq ($(words $(MAKECMDGOALS)),1)
331            mixed-build := 1
332        endif
333    endif
334endif
335
336# We cannot build single targets and the others at the same time
337ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
338    single-build := 1
339    ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
340        mixed-build := 1
341    endif
342endif
343
344# For "make -j clean all", "make -j mrproper defconfig all", etc.
345ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
346    ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
347        mixed-build := 1
348    endif
349endif
350
351# install and modules_install need also be processed one by one
352ifneq ($(filter install,$(MAKECMDGOALS)),)
353    ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
354        mixed-build := 1
355    endif
356endif
357
358ifdef mixed-build
359# ===========================================================================
360# We're called with mixed targets (*config and build targets).
361# Handle them one by one.
362
363PHONY += $(MAKECMDGOALS) __build_one_by_one
364
365$(MAKECMDGOALS): __build_one_by_one
366	@:
367
368__build_one_by_one:
369	$(Q)set -e; \
370	for i in $(MAKECMDGOALS); do \
371		$(MAKE) -f $(srctree)/Makefile $$i; \
372	done
373
374else # !mixed-build
375
376include $(srctree)/scripts/Kbuild.include
377
378# Read KERNELRELEASE from include/config/kernel.release (if it exists)
379KERNELRELEASE = $(call read-file, $(objtree)/include/config/kernel.release)
380KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
381export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
382
383include $(srctree)/scripts/subarch.include
384
385# Cross compiling and selecting different set of gcc/bin-utils
386# ---------------------------------------------------------------------------
387#
388# When performing cross compilation for other architectures ARCH shall be set
389# to the target architecture. (See arch/* for the possibilities).
390# ARCH can be set during invocation of make:
391# make ARCH=arm64
392# Another way is to have ARCH set in the environment.
393# The default ARCH is the host where make is executed.
394
395# CROSS_COMPILE specify the prefix used for all executables used
396# during compilation. Only gcc and related bin-utils executables
397# are prefixed with $(CROSS_COMPILE).
398# CROSS_COMPILE can be set on the command line
399# make CROSS_COMPILE=aarch64-linux-gnu-
400# Alternatively CROSS_COMPILE can be set in the environment.
401# Default value for CROSS_COMPILE is not to prefix executables
402# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
403ARCH		?= $(SUBARCH)
404
405# Architecture as present in compile.h
406UTS_MACHINE 	:= $(ARCH)
407SRCARCH 	:= $(ARCH)
408
409# Additional ARCH settings for x86
410ifeq ($(ARCH),i386)
411        SRCARCH := x86
412endif
413ifeq ($(ARCH),x86_64)
414        SRCARCH := x86
415endif
416
417# Additional ARCH settings for sparc
418ifeq ($(ARCH),sparc32)
419       SRCARCH := sparc
420endif
421ifeq ($(ARCH),sparc64)
422       SRCARCH := sparc
423endif
424
425# Additional ARCH settings for parisc
426ifeq ($(ARCH),parisc64)
427       SRCARCH := parisc
428endif
429
430export cross_compiling :=
431ifneq ($(SRCARCH),$(SUBARCH))
432cross_compiling := 1
433endif
434
435KCONFIG_CONFIG	?= .config
436export KCONFIG_CONFIG
437
438# SHELL used by kbuild
439CONFIG_SHELL := sh
440
441HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
442HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
443HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
444
445ifneq ($(LLVM),)
446ifneq ($(filter %/,$(LLVM)),)
447LLVM_PREFIX := $(LLVM)
448else ifneq ($(filter -%,$(LLVM)),)
449LLVM_SUFFIX := $(LLVM)
450endif
451
452HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
453HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
454else
455HOSTCC	= gcc
456HOSTCXX	= g++
457endif
458HOSTRUSTC = rustc
459HOSTPKG_CONFIG	= pkg-config
460
461# the KERNELDOC macro needs to be exported, as scripts/Makefile.build
462# has a logic to call it
463KERNELDOC       = $(srctree)/scripts/kernel-doc.py
464export KERNELDOC
465
466KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
467			 -O2 -fomit-frame-pointer -std=gnu11
468KBUILD_USERCFLAGS  := $(KBUILD_USERHOSTCFLAGS) $(USERCFLAGS)
469KBUILD_USERLDFLAGS := $(USERLDFLAGS)
470
471# These flags apply to all Rust code in the tree, including the kernel and
472# host programs.
473export rust_common_flags := --edition=2021 \
474			    -Zbinary_dep_depinfo=y \
475			    -Astable_features \
476			    -Dnon_ascii_idents \
477			    -Dunsafe_op_in_unsafe_fn \
478			    -Wmissing_docs \
479			    -Wrust_2018_idioms \
480			    -Wunreachable_pub \
481			    -Wclippy::all \
482			    -Wclippy::ignored_unit_patterns \
483			    -Wclippy::mut_mut \
484			    -Wclippy::needless_bitwise_bool \
485			    -Aclippy::needless_lifetimes \
486			    -Wclippy::no_mangle_with_rust_abi \
487			    -Wclippy::undocumented_unsafe_blocks \
488			    -Wclippy::unnecessary_safety_comment \
489			    -Wclippy::unnecessary_safety_doc \
490			    -Wrustdoc::missing_crate_level_docs \
491			    -Wrustdoc::unescaped_backticks
492
493KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) \
494		       $(HOSTCFLAGS) -I $(srctree)/scripts/include
495KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS) \
496		       -I $(srctree)/scripts/include
497KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
498			-Zallow-features= $(HOSTRUSTFLAGS)
499KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
500KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
501KBUILD_PROCMACROLDFLAGS := $(or $(PROCMACROLDFLAGS),$(KBUILD_HOSTLDFLAGS))
502
503# Make variables (CC, etc...)
504CPP		= $(CC) -E
505ifneq ($(LLVM),)
506CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
507LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
508AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
509NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
510OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
511OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
512READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
513STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
514else
515CC		= $(CROSS_COMPILE)gcc
516LD		= $(CROSS_COMPILE)ld
517AR		= $(CROSS_COMPILE)ar
518NM		= $(CROSS_COMPILE)nm
519OBJCOPY		= $(CROSS_COMPILE)objcopy
520OBJDUMP		= $(CROSS_COMPILE)objdump
521READELF		= $(CROSS_COMPILE)readelf
522STRIP		= $(CROSS_COMPILE)strip
523endif
524RUSTC		= rustc
525RUSTDOC		= rustdoc
526RUSTFMT		= rustfmt
527CLIPPY_DRIVER	= clippy-driver
528BINDGEN		= bindgen
529PAHOLE		= pahole
530RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
531LEX		= flex
532YACC		= bison
533AWK		= awk
534INSTALLKERNEL  := installkernel
535PERL		= perl
536PYTHON3		= python3
537CHECK		= sparse
538BASH		= bash
539KGZIP		= gzip
540KBZIP2		= bzip2
541KLZOP		= lzop
542LZMA		= lzma
543LZ4		= lz4
544XZ		= xz
545ZSTD		= zstd
546
547CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
548		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
549NOSTDINC_FLAGS :=
550CFLAGS_MODULE   =
551RUSTFLAGS_MODULE =
552AFLAGS_MODULE   =
553LDFLAGS_MODULE  =
554CFLAGS_KERNEL	=
555RUSTFLAGS_KERNEL =
556AFLAGS_KERNEL	=
557LDFLAGS_vmlinux =
558
559# Use USERINCLUDE when you must reference the UAPI directories only.
560USERINCLUDE    := \
561		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
562		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
563		-I$(srctree)/include/uapi \
564		-I$(objtree)/include/generated/uapi \
565                -include $(srctree)/include/linux/compiler-version.h \
566                -include $(srctree)/include/linux/kconfig.h
567
568# Use LINUXINCLUDE when you must reference the include/ directory.
569# Needed to be compatible with the O= option
570LINUXINCLUDE    := \
571		-I$(srctree)/arch/$(SRCARCH)/include \
572		-I$(objtree)/arch/$(SRCARCH)/include/generated \
573		-I$(srctree)/include \
574		-I$(objtree)/include \
575		$(USERINCLUDE)
576
577KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
578
579KBUILD_CFLAGS :=
580KBUILD_CFLAGS += -std=gnu11
581KBUILD_CFLAGS += -fshort-wchar
582KBUILD_CFLAGS += -funsigned-char
583KBUILD_CFLAGS += -fno-common
584KBUILD_CFLAGS += -fno-PIE
585KBUILD_CFLAGS += -fno-strict-aliasing
586
587KBUILD_CPPFLAGS := -D__KERNEL__
588KBUILD_RUSTFLAGS := $(rust_common_flags) \
589		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
590		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
591		    -Csymbol-mangling-version=v0 \
592		    -Crelocation-model=static \
593		    -Zfunction-sections=n \
594		    -Wclippy::float_arithmetic
595
596KBUILD_AFLAGS_KERNEL :=
597KBUILD_CFLAGS_KERNEL :=
598KBUILD_RUSTFLAGS_KERNEL :=
599KBUILD_AFLAGS_MODULE  := -DMODULE
600KBUILD_CFLAGS_MODULE  := -DMODULE
601KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
602KBUILD_LDFLAGS_MODULE :=
603KBUILD_LDFLAGS :=
604CLANG_FLAGS :=
605
606ifeq ($(KBUILD_CLIPPY),1)
607	RUSTC_OR_CLIPPY_QUIET := CLIPPY
608	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
609else
610	RUSTC_OR_CLIPPY_QUIET := RUSTC
611	RUSTC_OR_CLIPPY = $(RUSTC)
612endif
613
614# Allows the usage of unstable features in stable compilers.
615export RUSTC_BOOTSTRAP := 1
616
617# Allows finding `.clippy.toml` in out-of-srctree builds.
618export CLIPPY_CONF_DIR := $(srctree)
619
620export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
621export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN
622export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
623export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
624export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
625export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
626export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS KBUILD_PROCMACROLDFLAGS LDFLAGS_MODULE
627export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
628
629export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
630export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
631export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
632export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
633export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
634export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
635
636# Files to ignore in find ... statements
637
638export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
639			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
640			  -prune -o
641
642# ===========================================================================
643# Rules shared between *config targets and build targets
644
645# Basic helpers built in scripts/basic/
646PHONY += scripts_basic
647scripts_basic:
648	$(Q)$(MAKE) $(build)=scripts/basic
649
650PHONY += outputmakefile
651ifdef building_out_of_srctree
652# Before starting out-of-tree build, make sure the source tree is clean.
653# outputmakefile generates a Makefile in the output directory, if using a
654# separate output directory. This allows convenient use of make in the
655# output directory.
656# At the same time when output Makefile generated, generate .gitignore to
657# ignore whole output directory
658
659ifdef KBUILD_EXTMOD
660print_env_for_makefile = \
661	echo "export KBUILD_OUTPUT = $(objtree)"; \
662	echo "export KBUILD_EXTMOD = $(realpath $(srcroot))" ; \
663	echo "export KBUILD_EXTMOD_OUTPUT = $(CURDIR)"
664else
665print_env_for_makefile = \
666	echo "export KBUILD_OUTPUT = $(CURDIR)"
667endif
668
669quiet_cmd_makefile = GEN     Makefile
670      cmd_makefile = { \
671	echo "\# Automatically generated by $(abs_srctree)/Makefile: don't edit"; \
672	$(print_env_for_makefile); \
673	echo "include $(abs_srctree)/Makefile"; \
674	} > Makefile
675
676outputmakefile:
677ifeq ($(KBUILD_EXTMOD),)
678	@if [ -f $(srctree)/.config -o \
679		 -d $(srctree)/include/config -o \
680		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
681		echo >&2 "***"; \
682		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
683		echo >&2 "*** in $(abs_srctree)";\
684		echo >&2 "***"; \
685		false; \
686	fi
687else
688	@if [ -f $(srcroot)/modules.order ]; then \
689		echo >&2 "***"; \
690		echo >&2 "*** The external module source tree is not clean."; \
691		echo >&2 "*** Please run 'make -C $(abs_srctree) M=$(realpath $(srcroot)) clean'"; \
692		echo >&2 "***"; \
693		false; \
694	fi
695endif
696	$(Q)ln -fsn $(srcroot) source
697	$(call cmd,makefile)
698	$(Q)test -e .gitignore || \
699	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
700endif
701
702# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
703# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
704# CC_VERSION_TEXT and RUSTC_VERSION_TEXT are referenced from Kconfig (so they
705# need export), and from include/config/auto.conf.cmd to detect the compiler
706# upgrade.
707CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
708RUSTC_VERSION_TEXT = $(subst $(pound),,$(shell $(RUSTC) --version 2>/dev/null))
709
710ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
711include $(srctree)/scripts/Makefile.clang
712endif
713
714# Include this also for config targets because some architectures need
715# cc-cross-prefix to determine CROSS_COMPILE.
716ifdef need-compiler
717include $(srctree)/scripts/Makefile.compiler
718endif
719
720ifdef config-build
721# ===========================================================================
722# *config targets only - make sure prerequisites are updated, and descend
723# in scripts/kconfig to make the *config target
724
725# Read arch-specific Makefile to set KBUILD_DEFCONFIG as needed.
726# KBUILD_DEFCONFIG may point out an alternative default configuration
727# used for 'make defconfig'
728include $(srctree)/arch/$(SRCARCH)/Makefile
729export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT RUSTC_VERSION_TEXT
730
731config: outputmakefile scripts_basic FORCE
732	$(Q)$(MAKE) $(build)=scripts/kconfig $@
733
734%config: outputmakefile scripts_basic FORCE
735	$(Q)$(MAKE) $(build)=scripts/kconfig $@
736
737else #!config-build
738# ===========================================================================
739# Build targets only - this includes vmlinux, arch-specific targets, clean
740# targets and others. In general all targets except *config targets.
741
742# If building an external module we do not care about the all: rule
743# but instead __all depend on modules
744PHONY += all
745ifeq ($(KBUILD_EXTMOD),)
746__all: all
747else
748__all: modules
749endif
750
751targets :=
752
753# Decide whether to build built-in, modular, or both.
754# Normally, just do built-in.
755
756KBUILD_MODULES :=
757KBUILD_BUILTIN := y
758
759# If we have only "make modules", don't compile built-in objects.
760ifeq ($(MAKECMDGOALS),modules)
761  KBUILD_BUILTIN :=
762endif
763
764# If we have "make <whatever> modules", compile modules
765# in addition to whatever we do anyway.
766# Just "make" or "make all" shall build modules as well
767
768ifneq ($(filter all modules nsdeps compile_commands.json clang-%,$(MAKECMDGOALS)),)
769  KBUILD_MODULES := y
770endif
771
772ifeq ($(MAKECMDGOALS),)
773  KBUILD_MODULES := y
774endif
775
776export KBUILD_MODULES KBUILD_BUILTIN
777
778ifdef need-config
779include $(objtree)/include/config/auto.conf
780endif
781
782ifeq ($(KBUILD_EXTMOD),)
783# Objects we will link into vmlinux / subdirs we need to visit
784core-y		:=
785drivers-y	:=
786libs-y		:= lib/
787endif # KBUILD_EXTMOD
788
789# The all: target is the default when no target is given on the
790# command line.
791# This allow a user to issue only 'make' to build a kernel including modules
792# Defaults to vmlinux, but the arch makefile usually adds further targets
793all: vmlinux
794
795CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
796ifdef CONFIG_CC_IS_GCC
797CFLAGS_GCOV	+= -fno-tree-loop-im
798endif
799export CFLAGS_GCOV
800
801# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
802ifdef CONFIG_FUNCTION_TRACER
803  CC_FLAGS_FTRACE := -pg
804endif
805
806include $(srctree)/arch/$(SRCARCH)/Makefile
807
808ifdef need-config
809ifdef may-sync-config
810# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
811# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
812# because some architectures define CROSS_COMPILE there.
813include include/config/auto.conf.cmd
814
815$(KCONFIG_CONFIG):
816	@echo >&2 '***'
817	@echo >&2 '*** Configuration file "$@" not found!'
818	@echo >&2 '***'
819	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
820	@echo >&2 '*** "make menuconfig" or "make xconfig").'
821	@echo >&2 '***'
822	@/bin/false
823
824# The actual configuration files used during the build are stored in
825# include/generated/ and include/config/. Update them if .config is newer than
826# include/config/auto.conf (which mirrors .config).
827#
828# This exploits the 'multi-target pattern rule' trick.
829# The syncconfig should be executed only once to make all the targets.
830# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
831#
832# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
833# so you cannot notice that Kconfig is waiting for the user input.
834%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
835	$(Q)$(kecho) "  SYNC    $@"
836	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
837else # !may-sync-config
838# External modules and some install targets need include/generated/autoconf.h
839# and include/config/auto.conf but do not care if they are up-to-date.
840# Use auto.conf to show the error message
841
842checked-configs := $(addprefix $(objtree)/, include/generated/autoconf.h include/generated/rustc_cfg include/config/auto.conf)
843missing-configs := $(filter-out $(wildcard $(checked-configs)), $(checked-configs))
844
845ifdef missing-configs
846PHONY += $(objtree)/include/config/auto.conf
847
848$(objtree)/include/config/auto.conf:
849	@echo   >&2 '***'
850	@echo   >&2 '***  ERROR: Kernel configuration is invalid. The following files are missing:'
851	@printf >&2 '***    - %s\n' $(missing-configs)
852	@echo   >&2 '***  Run "make oldconfig && make prepare" on kernel source to fix it.'
853	@echo   >&2 '***'
854	@/bin/false
855endif
856
857endif # may-sync-config
858endif # need-config
859
860KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
861
862ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
863KBUILD_CFLAGS += -O2
864KBUILD_RUSTFLAGS += -Copt-level=2
865else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
866KBUILD_CFLAGS += -Os
867KBUILD_RUSTFLAGS += -Copt-level=s
868endif
869
870# Always set `debug-assertions` and `overflow-checks` because their default
871# depends on `opt-level` and `debug-assertions`, respectively.
872KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
873KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
874
875# Tell gcc to never replace conditional load with a non-conditional one
876ifdef CONFIG_CC_IS_GCC
877# gcc-10 renamed --param=allow-store-data-races=0 to
878# -fno-allow-store-data-races.
879KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
880KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
881endif
882
883ifdef CONFIG_READABLE_ASM
884# Disable optimizations that make assembler listings hard to read.
885# reorder blocks reorders the control in the function
886# ipa clone creates specialized cloned functions
887# partial inlining inlines only parts of functions
888KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
889endif
890
891stackp-flags-y                                    := -fno-stack-protector
892stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
893stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
894
895KBUILD_CFLAGS += $(stackp-flags-y)
896
897KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
898KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
899
900ifdef CONFIG_FRAME_POINTER
901KBUILD_CFLAGS	+= -fno-omit-frame-pointer -fno-optimize-sibling-calls
902KBUILD_RUSTFLAGS += -Cforce-frame-pointers=y
903else
904# Some targets (ARM with Thumb2, for example), can't be built with frame
905# pointers.  For those, we don't have FUNCTION_TRACER automatically
906# select FRAME_POINTER.  However, FUNCTION_TRACER adds -pg, and this is
907# incompatible with -fomit-frame-pointer with current GCC, so we don't use
908# -fomit-frame-pointer with FUNCTION_TRACER.
909# In the Rust target specification, "frame-pointer" is set explicitly
910# to "may-omit".
911ifndef CONFIG_FUNCTION_TRACER
912KBUILD_CFLAGS	+= -fomit-frame-pointer
913endif
914endif
915
916# Initialize all stack variables with a 0xAA pattern.
917ifdef CONFIG_INIT_STACK_ALL_PATTERN
918KBUILD_CFLAGS	+= -ftrivial-auto-var-init=pattern
919endif
920
921# Initialize all stack variables with a zero value.
922ifdef CONFIG_INIT_STACK_ALL_ZERO
923KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
924ifdef CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_ENABLER
925# https://github.com/llvm/llvm-project/issues/44842
926CC_AUTO_VAR_INIT_ZERO_ENABLER := -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
927export CC_AUTO_VAR_INIT_ZERO_ENABLER
928KBUILD_CFLAGS	+= $(CC_AUTO_VAR_INIT_ZERO_ENABLER)
929endif
930endif
931
932# Explicitly clear padding bits during variable initialization
933KBUILD_CFLAGS += $(call cc-option,-fzero-init-padding-bits=all)
934
935# While VLAs have been removed, GCC produces unreachable stack probes
936# for the randomize_kstack_offset feature. Disable it for all compilers.
937KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
938
939# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
940ifdef CONFIG_ZERO_CALL_USED_REGS
941KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
942endif
943
944ifdef CONFIG_FUNCTION_TRACER
945ifdef CONFIG_FTRACE_MCOUNT_USE_CC
946  CC_FLAGS_FTRACE	+= -mrecord-mcount
947  ifdef CONFIG_HAVE_NOP_MCOUNT
948    ifeq ($(call cc-option-yn, -mnop-mcount),y)
949      CC_FLAGS_FTRACE	+= -mnop-mcount
950      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
951    endif
952  endif
953endif
954ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
955  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
956    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
957  endif
958endif
959ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
960  ifdef CONFIG_HAVE_C_RECORDMCOUNT
961    BUILD_C_RECORDMCOUNT := y
962    export BUILD_C_RECORDMCOUNT
963  endif
964endif
965ifdef CONFIG_HAVE_FENTRY
966  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
967  ifeq ($(call cc-option-yn, -mfentry),y)
968    CC_FLAGS_FTRACE	+= -mfentry
969    CC_FLAGS_USING	+= -DCC_USING_FENTRY
970  endif
971endif
972export CC_FLAGS_FTRACE
973KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
974KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
975endif
976
977# We trigger additional mismatches with less inlining
978ifdef CONFIG_DEBUG_SECTION_MISMATCH
979KBUILD_CFLAGS += -fno-inline-functions-called-once
980endif
981
982# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
983ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
984KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
985KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
986LDFLAGS_vmlinux += --gc-sections
987endif
988
989ifdef CONFIG_SHADOW_CALL_STACK
990ifndef CONFIG_DYNAMIC_SCS
991CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
992KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
993KBUILD_RUSTFLAGS += -Zsanitizer=shadow-call-stack
994endif
995export CC_FLAGS_SCS
996endif
997
998ifdef CONFIG_LTO_CLANG
999ifdef CONFIG_LTO_CLANG_THIN
1000CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
1001else
1002CC_FLAGS_LTO	:= -flto
1003endif
1004CC_FLAGS_LTO	+= -fvisibility=hidden
1005
1006# Limit inlining across translation units to reduce binary size
1007KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
1008endif
1009
1010ifdef CONFIG_LTO
1011KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
1012KBUILD_AFLAGS	+= -fno-lto
1013export CC_FLAGS_LTO
1014endif
1015
1016ifdef CONFIG_CFI_CLANG
1017CC_FLAGS_CFI	:= -fsanitize=kcfi
1018ifdef CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
1019	CC_FLAGS_CFI	+= -fsanitize-cfi-icall-experimental-normalize-integers
1020endif
1021ifdef CONFIG_FINEIBT_BHI
1022	CC_FLAGS_CFI	+= -fsanitize-kcfi-arity
1023endif
1024ifdef CONFIG_RUST
1025	# Always pass -Zsanitizer-cfi-normalize-integers as CONFIG_RUST selects
1026	# CONFIG_CFI_ICALL_NORMALIZE_INTEGERS.
1027	RUSTC_FLAGS_CFI   := -Zsanitizer=kcfi -Zsanitizer-cfi-normalize-integers
1028	KBUILD_RUSTFLAGS += $(RUSTC_FLAGS_CFI)
1029	export RUSTC_FLAGS_CFI
1030endif
1031KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1032export CC_FLAGS_CFI
1033endif
1034
1035# Architectures can define flags to add/remove for floating-point support
1036CC_FLAGS_FPU	+= -D_LINUX_FPU_COMPILATION_UNIT
1037export CC_FLAGS_FPU
1038export CC_FLAGS_NO_FPU
1039
1040ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1041# Set the minimal function alignment. Use the newer GCC option
1042# -fmin-function-alignment if it is available, or fall back to -falign-funtions.
1043# See also CONFIG_CC_HAS_SANE_FUNCTION_ALIGNMENT.
1044ifdef CONFIG_CC_HAS_MIN_FUNCTION_ALIGNMENT
1045KBUILD_CFLAGS += -fmin-function-alignment=$(CONFIG_FUNCTION_ALIGNMENT)
1046else
1047KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1048endif
1049endif
1050
1051# arch Makefile may override CC so keep this after arch Makefile is included
1052NOSTDINC_FLAGS += -nostdinc
1053
1054# To gain proper coverage for CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE,
1055# the kernel uses only C99 flexible arrays for dynamically sized trailing
1056# arrays. Enforce this for everything that may examine structure sizes and
1057# perform bounds checking.
1058KBUILD_CFLAGS += $(call cc-option, -fstrict-flex-arrays=3)
1059
1060# disable invalid "can't wrap" optimizations for signed / pointers
1061KBUILD_CFLAGS	+= -fno-strict-overflow
1062
1063# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1064KBUILD_CFLAGS  += -fno-stack-check
1065
1066# conserve stack if available
1067ifdef CONFIG_CC_IS_GCC
1068KBUILD_CFLAGS   += -fconserve-stack
1069endif
1070
1071# Ensure compilers do not transform certain loops into calls to wcslen()
1072KBUILD_CFLAGS += -fno-builtin-wcslen
1073
1074# change __FILE__ to the relative path to the source directory
1075ifdef building_out_of_srctree
1076KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srcroot)/=)
1077endif
1078
1079# include additional Makefiles when needed
1080include-y			:= scripts/Makefile.extrawarn
1081include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1082include-$(CONFIG_DEBUG_INFO_BTF)+= scripts/Makefile.btf
1083include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1084include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1085include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1086include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1087include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1088include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1089include-$(CONFIG_AUTOFDO_CLANG)	+= scripts/Makefile.autofdo
1090include-$(CONFIG_PROPELLER_CLANG)	+= scripts/Makefile.propeller
1091include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1092
1093include $(addprefix $(srctree)/, $(include-y))
1094
1095# scripts/Makefile.gcc-plugins is intentionally included last.
1096# Do not add $(call cc-option,...) below this line. When you build the kernel
1097# from the clean source tree, the GCC plugins do not exist at this point.
1098
1099# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1100KBUILD_CPPFLAGS += $(KCPPFLAGS)
1101KBUILD_AFLAGS   += $(KAFLAGS)
1102KBUILD_CFLAGS   += $(KCFLAGS)
1103KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1104
1105KBUILD_LDFLAGS_MODULE += --build-id=sha1
1106LDFLAGS_vmlinux += --build-id=sha1
1107
1108KBUILD_LDFLAGS	+= -z noexecstack
1109ifeq ($(CONFIG_LD_IS_BFD),y)
1110KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1111endif
1112
1113ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1114LDFLAGS_vmlinux	+= -X
1115endif
1116
1117ifeq ($(CONFIG_RELR),y)
1118# ld.lld before 15 did not support -z pack-relative-relocs.
1119LDFLAGS_vmlinux	+= $(call ld-option,--pack-dyn-relocs=relr,-z pack-relative-relocs)
1120endif
1121
1122# We never want expected sections to be placed heuristically by the
1123# linker. All sections should be explicitly named in the linker script.
1124ifdef CONFIG_LD_ORPHAN_WARN
1125LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1126endif
1127
1128ifneq ($(CONFIG_ARCH_VMLINUX_NEEDS_RELOCS),)
1129LDFLAGS_vmlinux	+= --emit-relocs --discard-none
1130endif
1131
1132# Align the bit size of userspace programs with the kernel
1133KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1134KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS))
1135
1136# userspace programs are linked via the compiler, use the correct linker
1137ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_LD_IS_LLD),yy)
1138KBUILD_USERLDFLAGS += --ld-path=$(LD)
1139endif
1140
1141# make the checker run with the right architecture
1142CHECKFLAGS += --arch=$(ARCH)
1143
1144# insure the checker run with the right endianness
1145CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1146
1147# the checker needs the correct machine size
1148CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1149
1150# Default kernel image to build when no specific target is given.
1151# KBUILD_IMAGE may be overruled on the command line or
1152# set in the environment
1153# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1154# this default value
1155export KBUILD_IMAGE ?= vmlinux
1156
1157#
1158# INSTALL_PATH specifies where to place the updated kernel and system map
1159# images. Default is /boot, but you can set it to other values
1160export	INSTALL_PATH ?= /boot
1161
1162#
1163# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1164# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1165# an argument if needed. Otherwise it defaults to the kernel install path
1166#
1167export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1168
1169#
1170# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1171# relocations required by build roots.  This is not defined in the
1172# makefile but the argument can be passed to make if needed.
1173#
1174
1175MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1176export MODLIB
1177
1178PHONY += prepare0
1179
1180ifeq ($(KBUILD_EXTMOD),)
1181
1182build-dir	:= .
1183clean-dirs	:= $(sort . Documentation \
1184		     $(patsubst %/,%,$(filter %/, $(core-) \
1185			$(drivers-) $(libs-))))
1186
1187export ARCH_CORE	:= $(core-y)
1188export ARCH_LIB		:= $(filter %/, $(libs-y))
1189export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1190# Externally visible symbols (used by link-vmlinux.sh)
1191
1192KBUILD_VMLINUX_OBJS := built-in.a $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1193KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1194
1195export KBUILD_VMLINUX_LIBS
1196export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1197
1198ifdef CONFIG_TRIM_UNUSED_KSYMS
1199# For the kernel to actually contain only the needed exported symbols,
1200# we have to build modules as well to determine what those symbols are.
1201KBUILD_MODULES := y
1202endif
1203
1204# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1205quiet_cmd_ar_vmlinux.a = AR      $@
1206      cmd_ar_vmlinux.a = \
1207	rm -f $@; \
1208	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1209	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1210
1211targets += vmlinux.a
1212vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt FORCE
1213	$(call if_changed,ar_vmlinux.a)
1214
1215PHONY += vmlinux_o
1216vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1217	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1218
1219vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1220	@:
1221
1222PHONY += vmlinux
1223# LDFLAGS_vmlinux in the top Makefile defines linker flags for the top vmlinux,
1224# not for decompressors. LDFLAGS_vmlinux in arch/*/boot/compressed/Makefile is
1225# unrelated; the decompressors just happen to have the same base name,
1226# arch/*/boot/compressed/vmlinux.
1227# Export LDFLAGS_vmlinux only to scripts/Makefile.vmlinux.
1228#
1229# _LDFLAGS_vmlinux is a workaround for the 'private export' bug:
1230#   https://savannah.gnu.org/bugs/?61463
1231# For Make > 4.4, the following simple code will work:
1232#  vmlinux: private export LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1233vmlinux: private _LDFLAGS_vmlinux := $(LDFLAGS_vmlinux)
1234vmlinux: export LDFLAGS_vmlinux = $(_LDFLAGS_vmlinux)
1235vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1236	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1237
1238# The actual objects are generated when descending,
1239# make sure no implicit rule kicks in
1240$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1241
1242ifeq ($(origin KERNELRELEASE),file)
1243filechk_kernel.release = $(srctree)/scripts/setlocalversion $(srctree)
1244else
1245filechk_kernel.release = echo $(KERNELRELEASE)
1246endif
1247
1248# Store (new) KERNELRELEASE string in include/config/kernel.release
1249include/config/kernel.release: FORCE
1250	$(call filechk,kernel.release)
1251
1252# Additional helpers built in scripts/
1253# Carefully list dependencies so we do not try to build scripts twice
1254# in parallel
1255PHONY += scripts
1256scripts: scripts_basic scripts_dtc
1257	$(Q)$(MAKE) $(build)=$(@)
1258
1259# Things we need to do before we recursively start building the kernel
1260# or the modules are listed in "prepare".
1261# A multi level approach is used. prepareN is processed before prepareN-1.
1262# archprepare is used in arch Makefiles and when processed asm symlink,
1263# version.h and scripts_basic is processed / created.
1264
1265PHONY += prepare archprepare
1266
1267archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1268	asm-generic $(version_h) include/generated/utsrelease.h \
1269	include/generated/compile.h include/generated/autoconf.h \
1270	include/generated/rustc_cfg remove-stale-files
1271
1272prepare0: archprepare
1273	$(Q)$(MAKE) $(build)=scripts/mod
1274	$(Q)$(MAKE) $(build)=. prepare
1275
1276# All the preparing..
1277prepare: prepare0
1278ifdef CONFIG_RUST
1279	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
1280	$(Q)$(MAKE) $(build)=rust
1281endif
1282
1283PHONY += remove-stale-files
1284remove-stale-files:
1285	$(Q)$(srctree)/scripts/remove-stale-files
1286
1287# Support for using generic headers in asm-generic
1288asm-generic := -f $(srctree)/scripts/Makefile.asm-headers obj
1289
1290PHONY += asm-generic uapi-asm-generic
1291asm-generic: uapi-asm-generic
1292	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1293	generic=include/asm-generic
1294uapi-asm-generic:
1295	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1296	generic=include/uapi/asm-generic
1297
1298# Generate some files
1299# ---------------------------------------------------------------------------
1300
1301# KERNELRELEASE can change from a few different places, meaning version.h
1302# needs to be updated, so this check is forced on all builds
1303
1304uts_len := 64
1305define filechk_utsrelease.h
1306	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1307	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1308	  exit 1;                                                         \
1309	fi;                                                               \
1310	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1311endef
1312
1313define filechk_version.h
1314	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1315		echo \#define LINUX_VERSION_CODE $(shell                 \
1316		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1317	else                                                             \
1318		echo \#define LINUX_VERSION_CODE $(shell                 \
1319		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1320	fi;                                                              \
1321	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1322	((c) > 255 ? 255 : (c)))';                                       \
1323	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1324	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1325	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1326endef
1327
1328$(version_h): private PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1329$(version_h): private SUBLEVEL := $(or $(SUBLEVEL), 0)
1330$(version_h): FORCE
1331	$(call filechk,version.h)
1332
1333include/generated/utsrelease.h: include/config/kernel.release FORCE
1334	$(call filechk,utsrelease.h)
1335
1336filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1337	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1338
1339include/generated/compile.h: FORCE
1340	$(call filechk,compile.h)
1341
1342PHONY += headerdep
1343headerdep:
1344	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1345	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1346
1347# ---------------------------------------------------------------------------
1348# Kernel headers
1349
1350#Default location for installed headers
1351export INSTALL_HDR_PATH = $(objtree)/usr
1352
1353quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1354      cmd_headers_install = \
1355	mkdir -p $(INSTALL_HDR_PATH); \
1356	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1357	usr/include $(INSTALL_HDR_PATH)
1358
1359PHONY += headers_install
1360headers_install: headers
1361	$(call cmd,headers_install)
1362
1363PHONY += archheaders archscripts
1364
1365hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1366
1367PHONY += headers
1368headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders
1369ifdef HEADER_ARCH
1370	$(Q)$(MAKE) -f $(srctree)/Makefile HEADER_ARCH= SRCARCH=$(HEADER_ARCH) headers
1371else
1372	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1373	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1374endif
1375
1376ifdef CONFIG_HEADERS_INSTALL
1377prepare: headers
1378endif
1379
1380PHONY += scripts_unifdef
1381scripts_unifdef: scripts_basic
1382	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1383
1384PHONY += scripts_gen_packed_field_checks
1385scripts_gen_packed_field_checks: scripts_basic
1386	$(Q)$(MAKE) $(build)=scripts scripts/gen_packed_field_checks
1387
1388# ---------------------------------------------------------------------------
1389# Install
1390
1391# Many distributions have the custom install script, /sbin/installkernel.
1392# If DKMS is installed, 'make install' will eventually recurse back
1393# to this Makefile to build and install external modules.
1394# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1395
1396quiet_cmd_install = INSTALL $(INSTALL_PATH)
1397      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1398
1399# ---------------------------------------------------------------------------
1400# vDSO install
1401
1402PHONY += vdso_install
1403vdso_install: export INSTALL_FILES = $(vdso-install-y)
1404vdso_install:
1405	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vdsoinst
1406
1407# ---------------------------------------------------------------------------
1408# Tools
1409
1410ifdef CONFIG_OBJTOOL
1411prepare: tools/objtool
1412endif
1413
1414ifdef CONFIG_BPF
1415ifdef CONFIG_DEBUG_INFO_BTF
1416prepare: tools/bpf/resolve_btfids
1417endif
1418endif
1419
1420# The tools build system is not a part of Kbuild and tends to introduce
1421# its own unique issues. If you need to integrate a new tool into Kbuild,
1422# please consider locating that tool outside the tools/ tree and using the
1423# standard Kbuild "hostprogs" syntax instead of adding a new tools/* entry
1424# here. See Documentation/kbuild/makefiles.rst for details.
1425
1426PHONY += resolve_btfids_clean
1427
1428resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1429
1430# tools/bpf/resolve_btfids directory might not exist
1431# in output directory, skip its clean in that case
1432resolve_btfids_clean:
1433ifneq ($(wildcard $(resolve_btfids_O)),)
1434	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1435endif
1436
1437tools/: FORCE
1438	$(Q)mkdir -p $(objtree)/tools
1439	$(Q)$(MAKE) LDFLAGS= O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1440
1441tools/%: FORCE
1442	$(Q)mkdir -p $(objtree)/tools
1443	$(Q)$(MAKE) LDFLAGS= O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1444
1445# ---------------------------------------------------------------------------
1446# Kernel selftest
1447
1448PHONY += kselftest
1449kselftest: headers
1450	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1451
1452kselftest-%: headers FORCE
1453	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1454
1455PHONY += kselftest-merge
1456kselftest-merge:
1457	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1458	$(Q)find $(srctree)/tools/testing/selftests -name config -o -name config.$(UTS_MACHINE) | \
1459		xargs $(srctree)/scripts/kconfig/merge_config.sh -y -m $(objtree)/.config
1460	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1461
1462# ---------------------------------------------------------------------------
1463# Devicetree files
1464
1465ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1466dtstree := arch/$(SRCARCH)/boot/dts
1467endif
1468
1469ifneq ($(dtstree),)
1470
1471%.dtb: dtbs_prepare
1472	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1473
1474%.dtbo: dtbs_prepare
1475	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1476
1477PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1478dtbs: dtbs_prepare
1479	$(Q)$(MAKE) $(build)=$(dtstree) need-dtbslist=1
1480
1481# include/config/kernel.release is actually needed when installing DTBs because
1482# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1483# dtbs_install depend on it as dtbs_install may run as root.
1484dtbs_prepare: include/config/kernel.release scripts_dtc
1485
1486ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1487export CHECK_DTBS=y
1488endif
1489
1490ifneq ($(CHECK_DTBS),)
1491dtbs_prepare: dt_binding_schemas
1492endif
1493
1494dtbs_check: dtbs
1495
1496dtbs_install:
1497	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.dtbinst obj=$(dtstree)
1498
1499ifdef CONFIG_OF_EARLY_FLATTREE
1500all: dtbs
1501endif
1502
1503ifdef CONFIG_GENERIC_BUILTIN_DTB
1504vmlinux: dtbs
1505endif
1506
1507endif
1508
1509PHONY += scripts_dtc
1510scripts_dtc: scripts_basic
1511	$(Q)$(MAKE) $(build)=scripts/dtc
1512
1513ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1514export CHECK_DTBS=y
1515endif
1516
1517PHONY += dt_binding_check dt_binding_schemas
1518dt_binding_check: dt_binding_schemas scripts_dtc
1519	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1520
1521dt_binding_schemas:
1522	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1523
1524PHONY += dt_compatible_check
1525dt_compatible_check: dt_binding_schemas
1526	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1527
1528# ---------------------------------------------------------------------------
1529# Modules
1530
1531ifdef CONFIG_MODULES
1532
1533# By default, build modules as well
1534
1535all: modules
1536
1537# When we're building modules with modversions, we need to consider
1538# the built-in objects during the descend as well, in order to
1539# make sure the checksums are up to date before we record them.
1540ifdef CONFIG_MODVERSIONS
1541  KBUILD_BUILTIN := y
1542endif
1543
1544# Build modules
1545#
1546
1547# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFO_BTF_MODULES
1548# is an exception.
1549ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1550KBUILD_BUILTIN := y
1551modules: vmlinux
1552endif
1553
1554modules: modules_prepare
1555
1556# Target to prepare building external modules
1557modules_prepare: prepare
1558	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1559
1560endif # CONFIG_MODULES
1561
1562###
1563# Cleaning is done on three levels.
1564# make clean     Delete most generated files
1565#                Leave enough to build external modules
1566# make mrproper  Delete the current configuration, and all generated files
1567# make distclean Remove editor backup files, patch leftover files and the like
1568
1569# Directories & files removed with 'make clean'
1570CLEAN_FILES += vmlinux.symvers modules-only.symvers \
1571	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1572	       modules.builtin.ranges vmlinux.o.map vmlinux.unstripped \
1573	       compile_commands.json rust/test \
1574	       rust-project.json .vmlinux.objs .vmlinux.export.c \
1575               .builtin-dtbs-list .builtin-dtb.S
1576
1577# Directories & files removed with 'make mrproper'
1578MRPROPER_FILES += include/config include/generated          \
1579		  arch/$(SRCARCH)/include/generated .objdiff \
1580		  debian snap tar-install PKGBUILD pacman \
1581		  .config .config.old .version \
1582		  Module.symvers \
1583		  certs/signing_key.pem \
1584		  certs/x509.genkey \
1585		  vmlinux-gdb.py \
1586		  rpmbuild \
1587		  rust/libmacros.so rust/libmacros.dylib
1588
1589# clean - Delete most, but leave enough to build external modules
1590#
1591clean: private rm-files := $(CLEAN_FILES)
1592
1593PHONY += archclean vmlinuxclean
1594
1595vmlinuxclean:
1596	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1597	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1598
1599clean: archclean vmlinuxclean resolve_btfids_clean
1600
1601# mrproper - Delete all generated files, including .config
1602#
1603mrproper: private rm-files := $(MRPROPER_FILES)
1604mrproper-dirs      := $(addprefix _mrproper_,scripts)
1605
1606PHONY += $(mrproper-dirs) mrproper
1607$(mrproper-dirs):
1608	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1609
1610mrproper: clean $(mrproper-dirs)
1611	$(call cmd,rmfiles)
1612	@find . $(RCS_FIND_IGNORE) \
1613		\( -name '*.rmeta' \) \
1614		-type f -print | xargs rm -f
1615
1616# distclean
1617#
1618PHONY += distclean
1619
1620distclean: mrproper
1621	@find . $(RCS_FIND_IGNORE) \
1622		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1623		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1624		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1625		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1626		-type f -print | xargs rm -f
1627
1628
1629# Packaging of the kernel to various formats
1630# ---------------------------------------------------------------------------
1631
1632%src-pkg: FORCE
1633	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1634%pkg: include/config/kernel.release FORCE
1635	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1636
1637# Brief documentation of the typical targets used
1638# ---------------------------------------------------------------------------
1639
1640boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1641boards := $(sort $(notdir $(boards)))
1642board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1643board-dirs := $(sort $(notdir $(board-dirs:/=)))
1644
1645PHONY += help
1646help:
1647	@echo  'Cleaning targets:'
1648	@echo  '  clean		  - Remove most generated files but keep the config and'
1649	@echo  '                    enough build support to build external modules'
1650	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1651	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1652	@echo  ''
1653	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1654	@echo  ''
1655	@echo  'Other generic targets:'
1656	@echo  '  all		  - Build all targets marked with [*]'
1657	@echo  '* vmlinux	  - Build the bare kernel'
1658	@echo  '* modules	  - Build all modules'
1659	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1660	@echo  '  vdso_install    - Install unstripped vdso to INSTALL_MOD_PATH (default: /)'
1661	@echo  '  dir/            - Build all files in dir and below'
1662	@echo  '  dir/file.[ois]  - Build specified target only'
1663	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1664	@echo  '                    (requires compiler support for LLVM assembly generation)'
1665	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1666	@echo  '                    (requires a recent binutils and recent build (System.map))'
1667	@echo  '  dir/file.ko     - Build module including final link'
1668	@echo  '  modules_prepare - Set up for building external modules'
1669	@echo  '  tags/TAGS	  - Generate tags file for editors'
1670	@echo  '  cscope	  - Generate cscope index'
1671	@echo  '  gtags           - Generate GNU GLOBAL index'
1672	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1673	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1674	@echo  '  image_name	  - Output the image name (use with make -s)'
1675	@echo  '  headers	  - Build ready-to-install UAPI headers in usr/include'
1676	@echo  '  headers_install - Install sanitised kernel UAPI headers to INSTALL_HDR_PATH'; \
1677	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1678	 echo  ''
1679	@echo  'Static analysers:'
1680	@echo  '  checkstack      - Generate a list of stack hogs and consider all functions'
1681	@echo  '                    with a stack size larger than MINSTACKSIZE (default: 100)'
1682	@echo  '  versioncheck    - Sanity check on version.h usage'
1683	@echo  '  includecheck    - Check for duplicate included header files'
1684	@echo  '  headerdep       - Detect inclusion cycles in headers'
1685	@echo  '  coccicheck      - Check with Coccinelle'
1686	@echo  '  clang-analyzer  - Check with clang static analyzer'
1687	@echo  '  clang-tidy      - Check with clang-tidy'
1688	@echo  ''
1689	@echo  'Tools:'
1690	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1691	@echo  ''
1692	@echo  'Kernel selftest:'
1693	@echo  '  kselftest         - Build and run kernel selftest'
1694	@echo  '                      Build, install, and boot kernel before'
1695	@echo  '                      running kselftest on it'
1696	@echo  '                      Run as root for full coverage'
1697	@echo  '  kselftest-all     - Build kernel selftest'
1698	@echo  '  kselftest-install - Build and install kernel selftest'
1699	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1700	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1701	@echo  '		      kselftest to existing .config.'
1702	@echo  ''
1703	@echo  'Rust targets:'
1704	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1705	@echo  '		    available and, if not, explains why.'
1706	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1707	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1708	@echo  '		    is formatted, printing a diff otherwise.'
1709	@echo  '  rustdoc	  - Generate Rust documentation'
1710	@echo  '		    (requires kernel .config)'
1711	@echo  '  rusttest        - Runs the Rust tests'
1712	@echo  '                    (requires kernel .config; downloads external repos)'
1713	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1714	@echo  '		    (requires kernel .config)'
1715	@echo  '  dir/file.[os]   - Build specified target only'
1716	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1717	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1718	@echo  '                    The output is not intended to be compilable.'
1719	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1720	@echo  ''
1721	@$(if $(dtstree), \
1722		echo 'Devicetree:'; \
1723		echo '* dtbs               - Build device tree blobs for enabled boards'; \
1724		echo '  dtbs_install       - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1725		echo '  dt_binding_check   - Validate device tree binding documents and examples'; \
1726		echo '  dt_binding_schemas - Build processed device tree binding schemas'; \
1727		echo '  dtbs_check         - Validate device tree source files';\
1728		echo '')
1729
1730	@echo 'Userspace tools targets:'
1731	@echo '  use "make tools/help"'
1732	@echo '  or  "cd tools; make help"'
1733	@echo  ''
1734	@echo  'Kernel packaging:'
1735	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1736	@echo  ''
1737	@echo  'Documentation targets:'
1738	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1739	@echo  ''
1740	@echo  'Architecture-specific targets ($(SRCARCH)):'
1741	@$(or $(archhelp),\
1742		echo '  No architecture-specific help defined for $(SRCARCH)')
1743	@echo  ''
1744	@$(if $(boards), \
1745		$(foreach b, $(boards), \
1746		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1747		echo '')
1748	@$(if $(board-dirs), \
1749		$(foreach b, $(board-dirs), \
1750		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1751		printf "  %-16s - Show all of the above\\n" help-boards; \
1752		echo '')
1753
1754	@echo  '  make V=n   [targets] 1: verbose build'
1755	@echo  '                       2: give reason for rebuild of target'
1756	@echo  '                       V=1 and V=2 can be combined with V=12'
1757	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1758	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1759	@echo  '                       (sparse by default)'
1760	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1761	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1762	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3,c,e where'
1763	@echo  '		1: warnings which may be relevant and do not occur too often'
1764	@echo  '		2: warnings which occur quite often but may still be relevant'
1765	@echo  '		3: more obscure warnings, can most likely be ignored'
1766	@echo  '		c: extra checks in the configuration stage (Kconfig)'
1767	@echo  '		e: warnings are being treated as errors'
1768	@echo  '		Multiple levels can be combined with W=12 or W=123'
1769	@$(if $(dtstree), \
1770		echo '  make CHECK_DTBS=1 [targets] Check all generated dtb files against schema'; \
1771		echo '         This can be applied both to "dtbs" and to individual "foo.dtb" targets' ; \
1772		)
1773	@echo  ''
1774	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1775	@echo  'For further info see the ./README file'
1776
1777
1778help-board-dirs := $(addprefix help-,$(board-dirs))
1779
1780help-boards: $(help-board-dirs)
1781
1782boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1783
1784$(help-board-dirs): help-%:
1785	@echo  'Architecture-specific targets ($(SRCARCH) $*):'
1786	@$(if $(boards-per-dir), \
1787		$(foreach b, $(boards-per-dir), \
1788		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1789		echo '')
1790
1791
1792# Documentation targets
1793# ---------------------------------------------------------------------------
1794DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1795	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1796PHONY += $(DOC_TARGETS)
1797$(DOC_TARGETS):
1798	$(Q)$(MAKE) $(build)=Documentation $@
1799
1800
1801# Rust targets
1802# ---------------------------------------------------------------------------
1803
1804# "Is Rust available?" target
1805PHONY += rustavailable
1806rustavailable:
1807	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh && echo "Rust is available!"
1808
1809# Documentation target
1810#
1811# Using the singular to avoid running afoul of `no-dot-config-targets`.
1812PHONY += rustdoc
1813rustdoc: prepare
1814	$(Q)$(MAKE) $(build)=rust $@
1815
1816# Testing target
1817PHONY += rusttest
1818rusttest: prepare
1819	$(Q)$(MAKE) $(build)=rust $@
1820
1821# Formatting targets
1822PHONY += rustfmt rustfmtcheck
1823
1824rustfmt:
1825	$(Q)find $(srctree) $(RCS_FIND_IGNORE) \
1826		-type f -a -name '*.rs' -a ! -name '*generated*' -print \
1827		| xargs $(RUSTFMT) $(rustfmt_flags)
1828
1829rustfmtcheck: rustfmt_flags = --check
1830rustfmtcheck: rustfmt
1831
1832# Misc
1833# ---------------------------------------------------------------------------
1834
1835PHONY += misc-check
1836misc-check:
1837	$(Q)$(srctree)/scripts/misc-check
1838
1839all: misc-check
1840
1841PHONY += scripts_gdb
1842scripts_gdb: prepare0
1843	$(Q)$(MAKE) $(build)=scripts/gdb
1844	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1845
1846ifdef CONFIG_GDB_SCRIPTS
1847all: scripts_gdb
1848endif
1849
1850else # KBUILD_EXTMOD
1851
1852filechk_kernel.release = echo $(KERNELRELEASE)
1853
1854###
1855# External module support.
1856# When building external modules the kernel used as basis is considered
1857# read-only, and no consistency checks are made and the make
1858# system is not used on the basis kernel. If updates are required
1859# in the basis kernel ordinary make commands (without M=...) must be used.
1860
1861# We are always building only modules.
1862KBUILD_BUILTIN :=
1863KBUILD_MODULES := y
1864
1865build-dir := .
1866
1867clean-dirs := .
1868clean: private rm-files := Module.symvers modules.nsdeps compile_commands.json
1869
1870PHONY += prepare
1871# now expand this into a simple variable to reduce the cost of shell evaluations
1872prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1873prepare:
1874	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1875		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1876		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1877		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1878	fi
1879
1880PHONY += help
1881help:
1882	@echo  '  Building external modules.'
1883	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1884	@echo  ''
1885	@echo  '  modules         - default target, build the module(s)'
1886	@echo  '  modules_install - install the module'
1887	@echo  '  clean           - remove generated files in module directory only'
1888	@echo  '  rust-analyzer	  - generate rust-project.json rust-analyzer support file'
1889	@echo  ''
1890
1891ifndef CONFIG_MODULES
1892modules modules_install: __external_modules_error
1893__external_modules_error:
1894	@echo >&2 '***'
1895	@echo >&2 '*** The present kernel disabled CONFIG_MODULES.'
1896	@echo >&2 '*** You cannot build or install external modules.'
1897	@echo >&2 '***'
1898	@false
1899endif
1900
1901endif # KBUILD_EXTMOD
1902
1903# ---------------------------------------------------------------------------
1904# Modules
1905
1906PHONY += modules modules_install modules_sign modules_prepare
1907
1908modules_install:
1909	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst \
1910	sign-only=$(if $(filter modules_install,$(MAKECMDGOALS)),,y)
1911
1912ifeq ($(CONFIG_MODULE_SIG),y)
1913# modules_sign is a subset of modules_install.
1914# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1915modules_sign: modules_install
1916	@:
1917else
1918modules_sign:
1919	@echo >&2 '***'
1920	@echo >&2 '*** CONFIG_MODULE_SIG is disabled. You cannot sign modules.'
1921	@echo >&2 '***'
1922	@false
1923endif
1924
1925ifdef CONFIG_MODULES
1926
1927modules.order: $(build-dir)
1928	@:
1929
1930# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1931# This is solely useful to speed up test compiles.
1932modules: modpost
1933ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1934	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1935endif
1936
1937PHONY += modules_check
1938modules_check: modules.order
1939	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1940
1941else # CONFIG_MODULES
1942
1943modules:
1944	@:
1945
1946KBUILD_MODULES :=
1947
1948endif # CONFIG_MODULES
1949
1950PHONY += modpost
1951modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1952	 $(if $(KBUILD_MODULES), modules_check)
1953	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1954
1955# Single targets
1956# ---------------------------------------------------------------------------
1957# To build individual files in subdirectories, you can do like this:
1958#
1959#   make foo/bar/baz.s
1960#
1961# The supported suffixes for single-target are listed in 'single-targets'
1962#
1963# To build only under specific subdirectories, you can do like this:
1964#
1965#   make foo/bar/baz/
1966
1967ifdef single-build
1968
1969# .ko is special because modpost is needed
1970single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1971single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1972		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1973
1974$(single-ko): single_modules
1975	@:
1976$(single-no-ko): $(build-dir)
1977	@:
1978
1979# Remove modules.order when done because it is not the real one.
1980PHONY += single_modules
1981single_modules: $(single-no-ko) modules_prepare
1982	$(Q){ $(foreach m, $(single-ko), echo $(m:%.ko=%.o);) } > modules.order
1983	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1984ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1985	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1986endif
1987	$(Q)rm -f modules.order
1988
1989single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1990
1991KBUILD_MODULES := y
1992
1993endif
1994
1995prepare: outputmakefile
1996
1997# Preset locale variables to speed up the build process. Limit locale
1998# tweaks to this spot to avoid wrong language settings when running
1999# make menuconfig etc.
2000# Error messages still appears in the original language
2001PHONY += $(build-dir)
2002$(build-dir): prepare
2003	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
2004
2005clean-dirs := $(addprefix _clean_, $(clean-dirs))
2006PHONY += $(clean-dirs) clean
2007$(clean-dirs):
2008	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2009
2010clean: $(clean-dirs)
2011	$(call cmd,rmfiles)
2012	@find . $(RCS_FIND_IGNORE) \
2013		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2014		-o -name '*.ko.*' \
2015		-o -name '*.dtb' -o -name '*.dtbo' \
2016		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2017		-o -name '*.dt.yaml' -o -name 'dtbs-list' \
2018		-o -name '*.dwo' -o -name '*.lst' \
2019		-o -name '*.su' -o -name '*.mod' \
2020		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2021		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2022		-o -name '*.asn1.[ch]' \
2023		-o -name '*.symtypes' -o -name 'modules.order' \
2024		-o -name '*.c.[012]*.*' \
2025		-o -name '*.ll' \
2026		-o -name '*.gcno' \
2027		\) -type f -print \
2028		-o -name '.tmp_*' -print \
2029		| xargs rm -rf
2030
2031# Generate tags for editors
2032# ---------------------------------------------------------------------------
2033quiet_cmd_tags = GEN     $@
2034      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2035
2036tags TAGS cscope gtags: FORCE
2037	$(call cmd,tags)
2038
2039# Generate rust-project.json (a file that describes the structure of non-Cargo
2040# Rust projects) for rust-analyzer (an implementation of the Language Server
2041# Protocol).
2042PHONY += rust-analyzer
2043rust-analyzer:
2044	+$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh
2045ifdef KBUILD_EXTMOD
2046# FIXME: external modules must not descend into a sub-directory of the kernel
2047	$(Q)$(MAKE) $(build)=$(objtree)/rust src=$(srctree)/rust $@
2048else
2049	$(Q)$(MAKE) $(build)=rust $@
2050endif
2051
2052# Script to generate missing namespace dependencies
2053# ---------------------------------------------------------------------------
2054
2055PHONY += nsdeps
2056nsdeps: export KBUILD_NSDEPS=1
2057nsdeps: modules
2058	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2059
2060# Clang Tooling
2061# ---------------------------------------------------------------------------
2062
2063quiet_cmd_gen_compile_commands = GEN     $@
2064      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2065
2066compile_commands.json: $(srctree)/scripts/clang-tools/gen_compile_commands.py \
2067	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2068	$(if $(CONFIG_MODULES), modules.order) FORCE
2069	$(call if_changed,gen_compile_commands)
2070
2071targets += compile_commands.json
2072
2073PHONY += clang-tidy clang-analyzer
2074
2075ifdef CONFIG_CC_IS_CLANG
2076quiet_cmd_clang_tools = CHECK   $<
2077      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2078
2079clang-tidy clang-analyzer: compile_commands.json
2080	$(call cmd,clang_tools)
2081else
2082clang-tidy clang-analyzer:
2083	@echo "$@ requires CC=clang" >&2
2084	@false
2085endif
2086
2087# Scripts to check various things for consistency
2088# ---------------------------------------------------------------------------
2089
2090PHONY += includecheck versioncheck coccicheck
2091
2092includecheck:
2093	find $(srctree)/* $(RCS_FIND_IGNORE) \
2094		-name '*.[hcS]' -type f -print | sort \
2095		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2096
2097versioncheck:
2098	find $(srctree)/* $(RCS_FIND_IGNORE) \
2099		-name '*.[hcS]' -type f -print | sort \
2100		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2101
2102coccicheck:
2103	$(Q)$(BASH) $(srctree)/scripts/$@
2104
2105PHONY += checkstack kernelrelease kernelversion image_name
2106
2107# UML needs a little special treatment here.  It wants to use the host
2108# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2109# else wants $(ARCH), including people doing cross-builds, which means
2110# that $(SUBARCH) doesn't work here.
2111ifeq ($(ARCH), um)
2112CHECKSTACK_ARCH := $(SUBARCH)
2113else
2114CHECKSTACK_ARCH := $(ARCH)
2115endif
2116MINSTACKSIZE	?= 100
2117checkstack:
2118	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2119	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH) $(MINSTACKSIZE)
2120
2121kernelrelease:
2122	@$(filechk_kernel.release)
2123
2124kernelversion:
2125	@echo $(KERNELVERSION)
2126
2127image_name:
2128	@echo $(KBUILD_IMAGE)
2129
2130PHONY += run-command
2131run-command:
2132	$(Q)$(KBUILD_RUN_COMMAND)
2133
2134quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2135      cmd_rmfiles = rm -rf $(rm-files)
2136
2137# read saved command lines for existing targets
2138existing-targets := $(wildcard $(sort $(targets)))
2139
2140-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2141
2142endif # config-build
2143endif # mixed-build
2144endif # need-sub-make
2145
2146PHONY += FORCE
2147FORCE:
2148
2149# Declare the contents of the PHONY variable as phony.  We keep that
2150# information in a variable so we can use it in if_changed and friends.
2151.PHONY: $(PHONY)
2152