xref: /openbmc/linux/Makefile (revision 292a089d)
1# SPDX-License-Identifier: GPL-2.0
2VERSION = 6
3PATCHLEVEL = 1
4SUBLEVEL = 0
5EXTRAVERSION =
6NAME = Hurr durr I'ma ninja sloth
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 ($(filter undefine,$(.FEATURES)),)
15$(error GNU Make >= 3.82 is required. Your Make version is $(MAKE_VERSION))
16endif
17
18$(if $(filter __%, $(MAKECMDGOALS)), \
19	$(error targets prefixed with '__' are only for internal use))
20
21# That's our default target when none is given on the command line
22PHONY := __all
23__all:
24
25# We are using a recursive build, so we need to do a little thinking
26# to get the ordering right.
27#
28# Most importantly: sub-Makefiles should only ever modify files in
29# their own directory. If in some directory we have a dependency on
30# a file in another dir (which doesn't happen often, but it's often
31# unavoidable when linking the built-in.a targets which finally
32# turn into vmlinux), we will call a sub make in that other dir, and
33# after that we are sure that everything which is in that other dir
34# is now up to date.
35#
36# The only cases where we need to modify files which have global
37# effects are thus separated out and done before the recursive
38# descending is started. They are now explicitly listed as the
39# prepare rule.
40
41ifneq ($(sub_make_done),1)
42
43# Do not use make's built-in rules and variables
44# (this increases performance and avoids hard-to-debug behaviour)
45MAKEFLAGS += -rR
46
47# Avoid funny character set dependencies
48unexport LC_ALL
49LC_COLLATE=C
50LC_NUMERIC=C
51export LC_COLLATE LC_NUMERIC
52
53# Avoid interference with shell env settings
54unexport GREP_OPTIONS
55
56# Beautify output
57# ---------------------------------------------------------------------------
58#
59# Normally, we echo the whole command before executing it. By making
60# that echo $($(quiet)$(cmd)), we now have the possibility to set
61# $(quiet) to choose other forms of output instead, e.g.
62#
63#         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
64#         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
65#
66# If $(quiet) is empty, the whole command will be printed.
67# If it is set to "quiet_", only the short version will be printed.
68# If it is set to "silent_", nothing will be printed at all, since
69# the variable $(silent_cmd_cc_o_c) doesn't exist.
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)ln $@ :<
75#
76# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
77# If KBUILD_VERBOSE equals 1 then the above command is displayed.
78# If KBUILD_VERBOSE equals 2 then give the reason why each target is rebuilt.
79#
80# To put more focus on warnings, be less verbose as default
81# Use 'make V=1' to see the full commands
82
83ifeq ("$(origin V)", "command line")
84  KBUILD_VERBOSE = $(V)
85endif
86ifndef KBUILD_VERBOSE
87  KBUILD_VERBOSE = 0
88endif
89
90ifeq ($(KBUILD_VERBOSE),1)
91  quiet =
92  Q =
93else
94  quiet=quiet_
95  Q = @
96endif
97
98# If the user is running make -s (silent mode), suppress echoing of
99# commands
100# make-4.0 (and later) keep single letter options in the 1st word of MAKEFLAGS.
101
102ifeq ($(filter 3.%,$(MAKE_VERSION)),)
103silence:=$(findstring s,$(firstword -$(MAKEFLAGS)))
104else
105silence:=$(findstring s,$(filter-out --%,$(MAKEFLAGS)))
106endif
107
108ifeq ($(silence),s)
109quiet=silent_
110KBUILD_VERBOSE = 0
111endif
112
113export quiet Q KBUILD_VERBOSE
114
115# Call a source code checker (by default, "sparse") as part of the
116# C compilation.
117#
118# Use 'make C=1' to enable checking of only re-compiled files.
119# Use 'make C=2' to enable checking of *all* source files, regardless
120# of whether they are re-compiled or not.
121#
122# See the file "Documentation/dev-tools/sparse.rst" for more details,
123# including where to get the "sparse" utility.
124
125ifeq ("$(origin C)", "command line")
126  KBUILD_CHECKSRC = $(C)
127endif
128ifndef KBUILD_CHECKSRC
129  KBUILD_CHECKSRC = 0
130endif
131
132export KBUILD_CHECKSRC
133
134# Enable "clippy" (a linter) as part of the Rust compilation.
135#
136# Use 'make CLIPPY=1' to enable it.
137ifeq ("$(origin CLIPPY)", "command line")
138  KBUILD_CLIPPY := $(CLIPPY)
139endif
140
141export KBUILD_CLIPPY
142
143# Use make M=dir or set the environment variable KBUILD_EXTMOD to specify the
144# directory of external module to build. Setting M= takes precedence.
145ifeq ("$(origin M)", "command line")
146  KBUILD_EXTMOD := $(M)
147endif
148
149$(if $(word 2, $(KBUILD_EXTMOD)), \
150	$(error building multiple external modules is not supported))
151
152$(foreach x, % :, $(if $(findstring $x, $(KBUILD_EXTMOD)), \
153	$(error module directory path cannot contain '$x')))
154
155# Remove trailing slashes
156ifneq ($(filter %/, $(KBUILD_EXTMOD)),)
157KBUILD_EXTMOD := $(shell dirname $(KBUILD_EXTMOD).)
158endif
159
160export KBUILD_EXTMOD
161
162# Kbuild will save output files in the current working directory.
163# This does not need to match to the root of the kernel source tree.
164#
165# For example, you can do this:
166#
167#  cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
168#
169# If you want to save output files in a different location, there are
170# two syntaxes to specify it.
171#
172# 1) O=
173# Use "make O=dir/to/store/output/files/"
174#
175# 2) Set KBUILD_OUTPUT
176# Set the environment variable KBUILD_OUTPUT to point to the output directory.
177# export KBUILD_OUTPUT=dir/to/store/output/files/; make
178#
179# The O= assignment takes precedence over the KBUILD_OUTPUT environment
180# variable.
181
182# Do we want to change the working directory?
183ifeq ("$(origin O)", "command line")
184  KBUILD_OUTPUT := $(O)
185endif
186
187ifneq ($(KBUILD_OUTPUT),)
188# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
189# expand a shell special character '~'. We use a somewhat tedious way here.
190abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
191$(if $(abs_objtree),, \
192     $(error failed to create output directory "$(KBUILD_OUTPUT)"))
193
194# $(realpath ...) resolves symlinks
195abs_objtree := $(realpath $(abs_objtree))
196else
197abs_objtree := $(CURDIR)
198endif # ifneq ($(KBUILD_OUTPUT),)
199
200ifeq ($(abs_objtree),$(CURDIR))
201# Suppress "Entering directory ..." unless we are changing the work directory.
202MAKEFLAGS += --no-print-directory
203else
204need-sub-make := 1
205endif
206
207this-makefile := $(lastword $(MAKEFILE_LIST))
208abs_srctree := $(realpath $(dir $(this-makefile)))
209
210ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
211$(error source directory cannot contain spaces or colons)
212endif
213
214ifneq ($(abs_srctree),$(abs_objtree))
215# Look for make include files relative to root of kernel src
216#
217# --included-dir is added for backward compatibility, but you should not rely on
218# it. Please add $(srctree)/ prefix to include Makefiles in the source tree.
219MAKEFLAGS += --include-dir=$(abs_srctree)
220endif
221
222ifneq ($(filter 3.%,$(MAKE_VERSION)),)
223# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
224# We need to invoke sub-make to avoid implicit rules in the top Makefile.
225need-sub-make := 1
226# Cancel implicit rules for this Makefile.
227$(this-makefile): ;
228endif
229
230export abs_srctree abs_objtree
231export sub_make_done := 1
232
233ifeq ($(need-sub-make),1)
234
235PHONY += $(MAKECMDGOALS) __sub-make
236
237$(filter-out $(this-makefile), $(MAKECMDGOALS)) __all: __sub-make
238	@:
239
240# Invoke a second make in the output directory, passing relevant variables
241__sub-make:
242	$(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
243
244endif # need-sub-make
245endif # sub_make_done
246
247# We process the rest of the Makefile if this is the final invocation of make
248ifeq ($(need-sub-make),)
249
250# Do not print "Entering directory ...",
251# but we want to display it when entering to the output directory
252# so that IDEs/editors are able to understand relative filenames.
253MAKEFLAGS += --no-print-directory
254
255ifeq ($(abs_srctree),$(abs_objtree))
256        # building in the source tree
257        srctree := .
258	building_out_of_srctree :=
259else
260        ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
261                # building in a subdirectory of the source tree
262                srctree := ..
263        else
264                srctree := $(abs_srctree)
265        endif
266	building_out_of_srctree := 1
267endif
268
269ifneq ($(KBUILD_ABS_SRCTREE),)
270srctree := $(abs_srctree)
271endif
272
273objtree		:= .
274VPATH		:= $(srctree)
275
276export building_out_of_srctree srctree objtree VPATH
277
278# To make sure we do not include .config for any of the *config targets
279# catch them early, and hand them over to scripts/kconfig/Makefile
280# It is allowed to specify more targets when calling make, including
281# mixing *config targets and build targets.
282# For example 'make oldconfig all'.
283# Detect when mixed targets is specified, and make a second invocation
284# of make so .config is not included in this case either (for *config).
285
286version_h := include/generated/uapi/linux/version.h
287
288clean-targets := %clean mrproper cleandocs
289no-dot-config-targets := $(clean-targets) \
290			 cscope gtags TAGS tags help% %docs check% coccicheck \
291			 $(version_h) headers headers_% archheaders archscripts \
292			 %asm-generic kernelversion %src-pkg dt_binding_check \
293			 outputmakefile rustavailable rustfmt rustfmtcheck
294# Installation targets should not require compiler. Unfortunately, vdso_install
295# is an exception where build artifacts may be updated. This must be fixed.
296no-compiler-targets := $(no-dot-config-targets) install dtbs_install \
297			headers_install modules_install kernelrelease image_name
298no-sync-config-targets := $(no-dot-config-targets) %install kernelrelease \
299			  image_name
300single-targets := %.a %.i %.rsi %.ko %.lds %.ll %.lst %.mod %.o %.s %.symtypes %/
301
302config-build	:=
303mixed-build	:=
304need-config	:= 1
305need-compiler	:= 1
306may-sync-config	:= 1
307single-build	:=
308
309ifneq ($(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-compiler-targets), $(MAKECMDGOALS)),)
316	ifeq ($(filter-out $(no-compiler-targets), $(MAKECMDGOALS)),)
317		need-compiler :=
318	endif
319endif
320
321ifneq ($(filter $(no-sync-config-targets), $(MAKECMDGOALS)),)
322	ifeq ($(filter-out $(no-sync-config-targets), $(MAKECMDGOALS)),)
323		may-sync-config :=
324	endif
325endif
326
327ifneq ($(KBUILD_EXTMOD),)
328	may-sync-config :=
329endif
330
331ifeq ($(KBUILD_EXTMOD),)
332        ifneq ($(filter %config,$(MAKECMDGOALS)),)
333		config-build := 1
334                ifneq ($(words $(MAKECMDGOALS)),1)
335			mixed-build := 1
336                endif
337        endif
338endif
339
340# We cannot build single targets and the others at the same time
341ifneq ($(filter $(single-targets), $(MAKECMDGOALS)),)
342	single-build := 1
343	ifneq ($(filter-out $(single-targets), $(MAKECMDGOALS)),)
344		mixed-build := 1
345	endif
346endif
347
348# For "make -j clean all", "make -j mrproper defconfig all", etc.
349ifneq ($(filter $(clean-targets),$(MAKECMDGOALS)),)
350        ifneq ($(filter-out $(clean-targets),$(MAKECMDGOALS)),)
351		mixed-build := 1
352        endif
353endif
354
355# install and modules_install need also be processed one by one
356ifneq ($(filter install,$(MAKECMDGOALS)),)
357        ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
358		mixed-build := 1
359        endif
360endif
361
362ifdef mixed-build
363# ===========================================================================
364# We're called with mixed targets (*config and build targets).
365# Handle them one by one.
366
367PHONY += $(MAKECMDGOALS) __build_one_by_one
368
369$(MAKECMDGOALS): __build_one_by_one
370	@:
371
372__build_one_by_one:
373	$(Q)set -e; \
374	for i in $(MAKECMDGOALS); do \
375		$(MAKE) -f $(srctree)/Makefile $$i; \
376	done
377
378else # !mixed-build
379
380include $(srctree)/scripts/Kbuild.include
381
382# Read KERNELRELEASE from include/config/kernel.release (if it exists)
383KERNELRELEASE = $(call read-file, include/config/kernel.release)
384KERNELVERSION = $(VERSION)$(if $(PATCHLEVEL),.$(PATCHLEVEL)$(if $(SUBLEVEL),.$(SUBLEVEL)))$(EXTRAVERSION)
385export VERSION PATCHLEVEL SUBLEVEL KERNELRELEASE KERNELVERSION
386
387include $(srctree)/scripts/subarch.include
388
389# Cross compiling and selecting different set of gcc/bin-utils
390# ---------------------------------------------------------------------------
391#
392# When performing cross compilation for other architectures ARCH shall be set
393# to the target architecture. (See arch/* for the possibilities).
394# ARCH can be set during invocation of make:
395# make ARCH=ia64
396# Another way is to have ARCH set in the environment.
397# The default ARCH is the host where make is executed.
398
399# CROSS_COMPILE specify the prefix used for all executables used
400# during compilation. Only gcc and related bin-utils executables
401# are prefixed with $(CROSS_COMPILE).
402# CROSS_COMPILE can be set on the command line
403# make CROSS_COMPILE=ia64-linux-
404# Alternatively CROSS_COMPILE can be set in the environment.
405# Default value for CROSS_COMPILE is not to prefix executables
406# Note: Some architectures assign CROSS_COMPILE in their arch/*/Makefile
407ARCH		?= $(SUBARCH)
408
409# Architecture as present in compile.h
410UTS_MACHINE 	:= $(ARCH)
411SRCARCH 	:= $(ARCH)
412
413# Additional ARCH settings for x86
414ifeq ($(ARCH),i386)
415        SRCARCH := x86
416endif
417ifeq ($(ARCH),x86_64)
418        SRCARCH := x86
419endif
420
421# Additional ARCH settings for sparc
422ifeq ($(ARCH),sparc32)
423       SRCARCH := sparc
424endif
425ifeq ($(ARCH),sparc64)
426       SRCARCH := sparc
427endif
428
429# Additional ARCH settings for parisc
430ifeq ($(ARCH),parisc64)
431       SRCARCH := parisc
432endif
433
434export cross_compiling :=
435ifneq ($(SRCARCH),$(SUBARCH))
436cross_compiling := 1
437endif
438
439KCONFIG_CONFIG	?= .config
440export KCONFIG_CONFIG
441
442# SHELL used by kbuild
443CONFIG_SHELL := sh
444
445HOST_LFS_CFLAGS := $(shell getconf LFS_CFLAGS 2>/dev/null)
446HOST_LFS_LDFLAGS := $(shell getconf LFS_LDFLAGS 2>/dev/null)
447HOST_LFS_LIBS := $(shell getconf LFS_LIBS 2>/dev/null)
448
449ifneq ($(LLVM),)
450ifneq ($(filter %/,$(LLVM)),)
451LLVM_PREFIX := $(LLVM)
452else ifneq ($(filter -%,$(LLVM)),)
453LLVM_SUFFIX := $(LLVM)
454endif
455
456HOSTCC	= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
457HOSTCXX	= $(LLVM_PREFIX)clang++$(LLVM_SUFFIX)
458else
459HOSTCC	= gcc
460HOSTCXX	= g++
461endif
462HOSTRUSTC = rustc
463HOSTPKG_CONFIG	= pkg-config
464
465KBUILD_USERHOSTCFLAGS := -Wall -Wmissing-prototypes -Wstrict-prototypes \
466			 -O2 -fomit-frame-pointer -std=gnu11 \
467			 -Wdeclaration-after-statement
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			    -Dunsafe_op_in_unsafe_fn -Drust_2018_idioms \
476			    -Dunreachable_pub -Dnon_ascii_idents \
477			    -Wmissing_docs \
478			    -Drustdoc::missing_crate_level_docs \
479			    -Dclippy::correctness -Dclippy::style \
480			    -Dclippy::suspicious -Dclippy::complexity \
481			    -Dclippy::perf \
482			    -Dclippy::let_unit_value -Dclippy::mut_mut \
483			    -Dclippy::needless_bitwise_bool \
484			    -Dclippy::needless_continue \
485			    -Wclippy::dbg_macro
486
487KBUILD_HOSTCFLAGS   := $(KBUILD_USERHOSTCFLAGS) $(HOST_LFS_CFLAGS) $(HOSTCFLAGS)
488KBUILD_HOSTCXXFLAGS := -Wall -O2 $(HOST_LFS_CFLAGS) $(HOSTCXXFLAGS)
489KBUILD_HOSTRUSTFLAGS := $(rust_common_flags) -O -Cstrip=debuginfo \
490			-Zallow-features= $(HOSTRUSTFLAGS)
491KBUILD_HOSTLDFLAGS  := $(HOST_LFS_LDFLAGS) $(HOSTLDFLAGS)
492KBUILD_HOSTLDLIBS   := $(HOST_LFS_LIBS) $(HOSTLDLIBS)
493
494# Make variables (CC, etc...)
495CPP		= $(CC) -E
496ifneq ($(LLVM),)
497CC		= $(LLVM_PREFIX)clang$(LLVM_SUFFIX)
498LD		= $(LLVM_PREFIX)ld.lld$(LLVM_SUFFIX)
499AR		= $(LLVM_PREFIX)llvm-ar$(LLVM_SUFFIX)
500NM		= $(LLVM_PREFIX)llvm-nm$(LLVM_SUFFIX)
501OBJCOPY		= $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX)
502OBJDUMP		= $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX)
503READELF		= $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX)
504STRIP		= $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX)
505else
506CC		= $(CROSS_COMPILE)gcc
507LD		= $(CROSS_COMPILE)ld
508AR		= $(CROSS_COMPILE)ar
509NM		= $(CROSS_COMPILE)nm
510OBJCOPY		= $(CROSS_COMPILE)objcopy
511OBJDUMP		= $(CROSS_COMPILE)objdump
512READELF		= $(CROSS_COMPILE)readelf
513STRIP		= $(CROSS_COMPILE)strip
514endif
515RUSTC		= rustc
516RUSTDOC		= rustdoc
517RUSTFMT		= rustfmt
518CLIPPY_DRIVER	= clippy-driver
519BINDGEN		= bindgen
520CARGO		= cargo
521PAHOLE		= pahole
522RESOLVE_BTFIDS	= $(objtree)/tools/bpf/resolve_btfids/resolve_btfids
523LEX		= flex
524YACC		= bison
525AWK		= awk
526INSTALLKERNEL  := installkernel
527DEPMOD		= depmod
528PERL		= perl
529PYTHON3		= python3
530CHECK		= sparse
531BASH		= bash
532KGZIP		= gzip
533KBZIP2		= bzip2
534KLZOP		= lzop
535LZMA		= lzma
536LZ4		= lz4c
537XZ		= xz
538ZSTD		= zstd
539
540PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) $(srctree)/scripts/pahole-flags.sh)
541
542CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
543		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
544NOSTDINC_FLAGS :=
545CFLAGS_MODULE   =
546RUSTFLAGS_MODULE =
547AFLAGS_MODULE   =
548LDFLAGS_MODULE  =
549CFLAGS_KERNEL	=
550RUSTFLAGS_KERNEL =
551AFLAGS_KERNEL	=
552export LDFLAGS_vmlinux =
553
554# Use USERINCLUDE when you must reference the UAPI directories only.
555USERINCLUDE    := \
556		-I$(srctree)/arch/$(SRCARCH)/include/uapi \
557		-I$(objtree)/arch/$(SRCARCH)/include/generated/uapi \
558		-I$(srctree)/include/uapi \
559		-I$(objtree)/include/generated/uapi \
560                -include $(srctree)/include/linux/compiler-version.h \
561                -include $(srctree)/include/linux/kconfig.h
562
563# Use LINUXINCLUDE when you must reference the include/ directory.
564# Needed to be compatible with the O= option
565LINUXINCLUDE    := \
566		-I$(srctree)/arch/$(SRCARCH)/include \
567		-I$(objtree)/arch/$(SRCARCH)/include/generated \
568		$(if $(building_out_of_srctree),-I$(srctree)/include) \
569		-I$(objtree)/include \
570		$(USERINCLUDE)
571
572KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
573KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
574		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
575		   -Werror=implicit-function-declaration -Werror=implicit-int \
576		   -Werror=return-type -Wno-format-security -funsigned-char \
577		   -std=gnu11
578KBUILD_CPPFLAGS := -D__KERNEL__
579KBUILD_RUSTFLAGS := $(rust_common_flags) \
580		    --target=$(objtree)/rust/target.json \
581		    -Cpanic=abort -Cembed-bitcode=n -Clto=n \
582		    -Cforce-unwind-tables=n -Ccodegen-units=1 \
583		    -Csymbol-mangling-version=v0 \
584		    -Crelocation-model=static \
585		    -Zfunction-sections=n \
586		    -Dclippy::float_arithmetic
587
588KBUILD_AFLAGS_KERNEL :=
589KBUILD_CFLAGS_KERNEL :=
590KBUILD_RUSTFLAGS_KERNEL :=
591KBUILD_AFLAGS_MODULE  := -DMODULE
592KBUILD_CFLAGS_MODULE  := -DMODULE
593KBUILD_RUSTFLAGS_MODULE := --cfg MODULE
594KBUILD_LDFLAGS_MODULE :=
595KBUILD_LDFLAGS :=
596CLANG_FLAGS :=
597
598ifeq ($(KBUILD_CLIPPY),1)
599	RUSTC_OR_CLIPPY_QUIET := CLIPPY
600	RUSTC_OR_CLIPPY = $(CLIPPY_DRIVER)
601else
602	RUSTC_OR_CLIPPY_QUIET := RUSTC
603	RUSTC_OR_CLIPPY = $(RUSTC)
604endif
605
606ifdef RUST_LIB_SRC
607	export RUST_LIB_SRC
608endif
609
610# Allows the usage of unstable features in stable compilers.
611export RUSTC_BOOTSTRAP := 1
612
613export ARCH SRCARCH CONFIG_SHELL BASH HOSTCC KBUILD_HOSTCFLAGS CROSS_COMPILE LD CC HOSTPKG_CONFIG
614export RUSTC RUSTDOC RUSTFMT RUSTC_OR_CLIPPY_QUIET RUSTC_OR_CLIPPY BINDGEN CARGO
615export HOSTRUSTC KBUILD_HOSTRUSTFLAGS
616export CPP AR NM STRIP OBJCOPY OBJDUMP READELF PAHOLE RESOLVE_BTFIDS LEX YACC AWK INSTALLKERNEL
617export PERL PYTHON3 CHECK CHECKFLAGS MAKE UTS_MACHINE HOSTCXX
618export KGZIP KBZIP2 KLZOP LZMA LZ4 XZ ZSTD
619export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
620export KBUILD_USERCFLAGS KBUILD_USERLDFLAGS
621
622export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
623export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
624export KBUILD_RUSTFLAGS RUSTFLAGS_KERNEL RUSTFLAGS_MODULE
625export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
626export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_RUSTFLAGS_MODULE KBUILD_LDFLAGS_MODULE
627export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL KBUILD_RUSTFLAGS_KERNEL
628export PAHOLE_FLAGS
629
630# Files to ignore in find ... statements
631
632export RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o    \
633			  -name CVS -o -name .pc -o -name .hg -o -name .git \) \
634			  -prune -o
635export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
636			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
637
638# ===========================================================================
639# Rules shared between *config targets and build targets
640
641# Basic helpers built in scripts/basic/
642PHONY += scripts_basic
643scripts_basic:
644	$(Q)$(MAKE) $(build)=scripts/basic
645
646PHONY += outputmakefile
647ifdef building_out_of_srctree
648# Before starting out-of-tree build, make sure the source tree is clean.
649# outputmakefile generates a Makefile in the output directory, if using a
650# separate output directory. This allows convenient use of make in the
651# output directory.
652# At the same time when output Makefile generated, generate .gitignore to
653# ignore whole output directory
654
655quiet_cmd_makefile = GEN     Makefile
656      cmd_makefile = { \
657	echo "\# Automatically generated by $(srctree)/Makefile: don't edit"; \
658	echo "include $(srctree)/Makefile"; \
659	} > Makefile
660
661outputmakefile:
662	@if [ -f $(srctree)/.config -o \
663		 -d $(srctree)/include/config -o \
664		 -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
665		echo >&2 "***"; \
666		echo >&2 "*** The source tree is not clean, please run 'make$(if $(findstring command line, $(origin ARCH)), ARCH=$(ARCH)) mrproper'"; \
667		echo >&2 "*** in $(abs_srctree)";\
668		echo >&2 "***"; \
669		false; \
670	fi
671	$(Q)ln -fsn $(srctree) source
672	$(call cmd,makefile)
673	$(Q)test -e .gitignore || \
674	{ echo "# this is build directory, ignore it"; echo "*"; } > .gitignore
675endif
676
677# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
678# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
679# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
680# and from include/config/auto.conf.cmd to detect the compiler upgrade.
681CC_VERSION_TEXT = $(subst $(pound),,$(shell LC_ALL=C $(CC) --version 2>/dev/null | head -n 1))
682
683ifneq ($(findstring clang,$(CC_VERSION_TEXT)),)
684include $(srctree)/scripts/Makefile.clang
685endif
686
687# Include this also for config targets because some architectures need
688# cc-cross-prefix to determine CROSS_COMPILE.
689ifdef need-compiler
690include $(srctree)/scripts/Makefile.compiler
691endif
692
693ifdef config-build
694# ===========================================================================
695# *config targets only - make sure prerequisites are updated, and descend
696# in scripts/kconfig to make the *config target
697
698# Read arch specific Makefile to set KBUILD_DEFCONFIG as needed.
699# KBUILD_DEFCONFIG may point out an alternative default configuration
700# used for 'make defconfig'
701include $(srctree)/arch/$(SRCARCH)/Makefile
702export KBUILD_DEFCONFIG KBUILD_KCONFIG CC_VERSION_TEXT
703
704config: outputmakefile scripts_basic FORCE
705	$(Q)$(MAKE) $(build)=scripts/kconfig $@
706
707%config: outputmakefile scripts_basic FORCE
708	$(Q)$(MAKE) $(build)=scripts/kconfig $@
709
710else #!config-build
711# ===========================================================================
712# Build targets only - this includes vmlinux, arch specific targets, clean
713# targets and others. In general all targets except *config targets.
714
715# If building an external module we do not care about the all: rule
716# but instead __all depend on modules
717PHONY += all
718ifeq ($(KBUILD_EXTMOD),)
719__all: all
720else
721__all: modules
722endif
723
724targets :=
725
726# Decide whether to build built-in, modular, or both.
727# Normally, just do built-in.
728
729KBUILD_MODULES :=
730KBUILD_BUILTIN := 1
731
732# If we have only "make modules", don't compile built-in objects.
733ifeq ($(MAKECMDGOALS),modules)
734  KBUILD_BUILTIN :=
735endif
736
737# If we have "make <whatever> modules", compile modules
738# in addition to whatever we do anyway.
739# Just "make" or "make all" shall build modules as well
740
741ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
742  KBUILD_MODULES := 1
743endif
744
745ifeq ($(MAKECMDGOALS),)
746  KBUILD_MODULES := 1
747endif
748
749export KBUILD_MODULES KBUILD_BUILTIN
750
751ifdef need-config
752include include/config/auto.conf
753endif
754
755ifeq ($(KBUILD_EXTMOD),)
756# Objects we will link into vmlinux / subdirs we need to visit
757core-y		:=
758drivers-y	:=
759libs-y		:= lib/
760endif # KBUILD_EXTMOD
761
762# The all: target is the default when no target is given on the
763# command line.
764# This allow a user to issue only 'make' to build a kernel including modules
765# Defaults to vmlinux, but the arch makefile usually adds further targets
766all: vmlinux
767
768CFLAGS_GCOV	:= -fprofile-arcs -ftest-coverage
769ifdef CONFIG_CC_IS_GCC
770CFLAGS_GCOV	+= -fno-tree-loop-im
771endif
772export CFLAGS_GCOV
773
774# The arch Makefiles can override CC_FLAGS_FTRACE. We may also append it later.
775ifdef CONFIG_FUNCTION_TRACER
776  CC_FLAGS_FTRACE := -pg
777endif
778
779include $(srctree)/arch/$(SRCARCH)/Makefile
780
781ifdef need-config
782ifdef may-sync-config
783# Read in dependencies to all Kconfig* files, make sure to run syncconfig if
784# changes are detected. This should be included after arch/$(SRCARCH)/Makefile
785# because some architectures define CROSS_COMPILE there.
786include include/config/auto.conf.cmd
787
788$(KCONFIG_CONFIG):
789	@echo >&2 '***'
790	@echo >&2 '*** Configuration file "$@" not found!'
791	@echo >&2 '***'
792	@echo >&2 '*** Please run some configurator (e.g. "make oldconfig" or'
793	@echo >&2 '*** "make menuconfig" or "make xconfig").'
794	@echo >&2 '***'
795	@/bin/false
796
797# The actual configuration files used during the build are stored in
798# include/generated/ and include/config/. Update them if .config is newer than
799# include/config/auto.conf (which mirrors .config).
800#
801# This exploits the 'multi-target pattern rule' trick.
802# The syncconfig should be executed only once to make all the targets.
803# (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
804#
805# Do not use $(call cmd,...) here. That would suppress prompts from syncconfig,
806# so you cannot notice that Kconfig is waiting for the user input.
807%/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h %/generated/rustc_cfg: $(KCONFIG_CONFIG)
808	$(Q)$(kecho) "  SYNC    $@"
809	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
810else # !may-sync-config
811# External modules and some install targets need include/generated/autoconf.h
812# and include/config/auto.conf but do not care if they are up-to-date.
813# Use auto.conf to trigger the test
814PHONY += include/config/auto.conf
815
816include/config/auto.conf:
817	@test -e include/generated/autoconf.h -a -e $@ || (		\
818	echo >&2;							\
819	echo >&2 "  ERROR: Kernel configuration is invalid.";		\
820	echo >&2 "         include/generated/autoconf.h or $@ are missing.";\
821	echo >&2 "         Run 'make oldconfig && make prepare' on kernel src to fix it.";	\
822	echo >&2 ;							\
823	/bin/false)
824
825endif # may-sync-config
826endif # need-config
827
828KBUILD_CFLAGS	+= -fno-delete-null-pointer-checks
829KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
830KBUILD_CFLAGS	+= $(call cc-disable-warning, format-truncation)
831KBUILD_CFLAGS	+= $(call cc-disable-warning, format-overflow)
832KBUILD_CFLAGS	+= $(call cc-disable-warning, address-of-packed-member)
833
834ifdef CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
835KBUILD_CFLAGS += -O2
836KBUILD_RUSTFLAGS += -Copt-level=2
837else ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
838KBUILD_CFLAGS += -Os
839KBUILD_RUSTFLAGS += -Copt-level=s
840endif
841
842# Always set `debug-assertions` and `overflow-checks` because their default
843# depends on `opt-level` and `debug-assertions`, respectively.
844KBUILD_RUSTFLAGS += -Cdebug-assertions=$(if $(CONFIG_RUST_DEBUG_ASSERTIONS),y,n)
845KBUILD_RUSTFLAGS += -Coverflow-checks=$(if $(CONFIG_RUST_OVERFLOW_CHECKS),y,n)
846
847# Tell gcc to never replace conditional load with a non-conditional one
848ifdef CONFIG_CC_IS_GCC
849# gcc-10 renamed --param=allow-store-data-races=0 to
850# -fno-allow-store-data-races.
851KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
852KBUILD_CFLAGS	+= $(call cc-option,-fno-allow-store-data-races)
853endif
854
855ifdef CONFIG_READABLE_ASM
856# Disable optimizations that make assembler listings hard to read.
857# reorder blocks reorders the control in the function
858# ipa clone creates specialized cloned functions
859# partial inlining inlines only parts of functions
860KBUILD_CFLAGS += -fno-reorder-blocks -fno-ipa-cp-clone -fno-partial-inlining
861endif
862
863ifneq ($(CONFIG_FRAME_WARN),0)
864KBUILD_CFLAGS += -Wframe-larger-than=$(CONFIG_FRAME_WARN)
865endif
866
867stackp-flags-y                                    := -fno-stack-protector
868stackp-flags-$(CONFIG_STACKPROTECTOR)             := -fstack-protector
869stackp-flags-$(CONFIG_STACKPROTECTOR_STRONG)      := -fstack-protector-strong
870
871KBUILD_CFLAGS += $(stackp-flags-y)
872
873KBUILD_CPPFLAGS-$(CONFIG_WERROR) += -Werror
874KBUILD_CPPFLAGS += $(KBUILD_CPPFLAGS-y)
875KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds
876
877KBUILD_RUSTFLAGS-$(CONFIG_WERROR) += -Dwarnings
878KBUILD_RUSTFLAGS += $(KBUILD_RUSTFLAGS-y)
879
880ifdef CONFIG_CC_IS_CLANG
881KBUILD_CPPFLAGS += -Qunused-arguments
882# The kernel builds with '-std=gnu11' so use of GNU extensions is acceptable.
883KBUILD_CFLAGS += -Wno-gnu
884else
885
886# gcc inanely warns about local variables called 'main'
887KBUILD_CFLAGS += -Wno-main
888endif
889
890# These warnings generated too much noise in a regular build.
891# Use make W=1 to enable them (see scripts/Makefile.extrawarn)
892KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
893KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
894
895# These result in bogus false positives
896KBUILD_CFLAGS += $(call cc-disable-warning, dangling-pointer)
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
924KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
925endif
926endif
927
928# While VLAs have been removed, GCC produces unreachable stack probes
929# for the randomize_kstack_offset feature. Disable it for all compilers.
930KBUILD_CFLAGS	+= $(call cc-option, -fno-stack-clash-protection)
931
932# Clear used registers at func exit (to reduce data lifetime and ROP gadgets).
933ifdef CONFIG_ZERO_CALL_USED_REGS
934KBUILD_CFLAGS	+= -fzero-call-used-regs=used-gpr
935endif
936
937ifdef CONFIG_FUNCTION_TRACER
938ifdef CONFIG_FTRACE_MCOUNT_USE_CC
939  CC_FLAGS_FTRACE	+= -mrecord-mcount
940  ifdef CONFIG_HAVE_NOP_MCOUNT
941    ifeq ($(call cc-option-yn, -mnop-mcount),y)
942      CC_FLAGS_FTRACE	+= -mnop-mcount
943      CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
944    endif
945  endif
946endif
947ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
948  ifdef CONFIG_HAVE_OBJTOOL_NOP_MCOUNT
949    CC_FLAGS_USING	+= -DCC_USING_NOP_MCOUNT
950  endif
951endif
952ifdef CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT
953  ifdef CONFIG_HAVE_C_RECORDMCOUNT
954    BUILD_C_RECORDMCOUNT := y
955    export BUILD_C_RECORDMCOUNT
956  endif
957endif
958ifdef CONFIG_HAVE_FENTRY
959  # s390-linux-gnu-gcc did not support -mfentry until gcc-9.
960  ifeq ($(call cc-option-yn, -mfentry),y)
961    CC_FLAGS_FTRACE	+= -mfentry
962    CC_FLAGS_USING	+= -DCC_USING_FENTRY
963  endif
964endif
965export CC_FLAGS_FTRACE
966KBUILD_CFLAGS	+= $(CC_FLAGS_FTRACE) $(CC_FLAGS_USING)
967KBUILD_AFLAGS	+= $(CC_FLAGS_USING)
968endif
969
970# We trigger additional mismatches with less inlining
971ifdef CONFIG_DEBUG_SECTION_MISMATCH
972KBUILD_CFLAGS += -fno-inline-functions-called-once
973endif
974
975# `rustc`'s `-Zfunction-sections` applies to data too (as of 1.59.0).
976ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
977KBUILD_CFLAGS_KERNEL += -ffunction-sections -fdata-sections
978KBUILD_RUSTFLAGS_KERNEL += -Zfunction-sections=y
979LDFLAGS_vmlinux += --gc-sections
980endif
981
982ifdef CONFIG_SHADOW_CALL_STACK
983ifndef CONFIG_DYNAMIC_SCS
984CC_FLAGS_SCS	:= -fsanitize=shadow-call-stack
985KBUILD_CFLAGS	+= $(CC_FLAGS_SCS)
986endif
987export CC_FLAGS_SCS
988endif
989
990ifdef CONFIG_LTO_CLANG
991ifdef CONFIG_LTO_CLANG_THIN
992CC_FLAGS_LTO	:= -flto=thin -fsplit-lto-unit
993KBUILD_LDFLAGS	+= --thinlto-cache-dir=$(extmod_prefix).thinlto-cache
994else
995CC_FLAGS_LTO	:= -flto
996endif
997CC_FLAGS_LTO	+= -fvisibility=hidden
998
999# Limit inlining across translation units to reduce binary size
1000KBUILD_LDFLAGS += -mllvm -import-instr-limit=5
1001
1002# Check for frame size exceeding threshold during prolog/epilog insertion
1003# when using lld < 13.0.0.
1004ifneq ($(CONFIG_FRAME_WARN),0)
1005ifeq ($(call test-lt, $(CONFIG_LLD_VERSION), 130000),y)
1006KBUILD_LDFLAGS	+= -plugin-opt=-warn-stack-size=$(CONFIG_FRAME_WARN)
1007endif
1008endif
1009endif
1010
1011ifdef CONFIG_LTO
1012KBUILD_CFLAGS	+= -fno-lto $(CC_FLAGS_LTO)
1013KBUILD_AFLAGS	+= -fno-lto
1014export CC_FLAGS_LTO
1015endif
1016
1017ifdef CONFIG_CFI_CLANG
1018CC_FLAGS_CFI	:= -fsanitize=kcfi
1019KBUILD_CFLAGS	+= $(CC_FLAGS_CFI)
1020export CC_FLAGS_CFI
1021endif
1022
1023ifneq ($(CONFIG_FUNCTION_ALIGNMENT),0)
1024KBUILD_CFLAGS += -falign-functions=$(CONFIG_FUNCTION_ALIGNMENT)
1025endif
1026
1027# arch Makefile may override CC so keep this after arch Makefile is included
1028NOSTDINC_FLAGS += -nostdinc
1029
1030# warn about C99 declaration after statement
1031KBUILD_CFLAGS += -Wdeclaration-after-statement
1032
1033# Variable Length Arrays (VLAs) should not be used anywhere in the kernel
1034KBUILD_CFLAGS += -Wvla
1035
1036# disable pointer signed / unsigned warnings in gcc 4.0
1037KBUILD_CFLAGS += -Wno-pointer-sign
1038
1039# In order to make sure new function cast mismatches are not introduced
1040# in the kernel (to avoid tripping CFI checking), the kernel should be
1041# globally built with -Wcast-function-type.
1042KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
1043
1044# disable stringop warnings in gcc 8+
1045KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
1046
1047# We'll want to enable this eventually, but it's not going away for 5.7 at least
1048KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
1049
1050# Another good warning that we'll want to enable eventually
1051KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
1052
1053# Enabled with W=2, disabled by default as noisy
1054ifdef CONFIG_CC_IS_GCC
1055KBUILD_CFLAGS += -Wno-maybe-uninitialized
1056endif
1057
1058# The allocators already balk at large sizes, so silence the compiler
1059# warnings for bounds checks involving those possible values. While
1060# -Wno-alloc-size-larger-than would normally be used here, earlier versions
1061# of gcc (<9.1) weirdly don't handle the option correctly when _other_
1062# warnings are produced (?!). Using -Walloc-size-larger-than=SIZE_MAX
1063# doesn't work (as it is documented to), silently resolving to "0" prior to
1064# version 9.1 (and producing an error more recently). Numeric values larger
1065# than PTRDIFF_MAX also don't work prior to version 9.1, which are silently
1066# ignored, continuing to default to PTRDIFF_MAX. So, left with no other
1067# choice, we must perform a versioned check to disable this warning.
1068# https://lore.kernel.org/lkml/20210824115859.187f272f@canb.auug.org.au
1069KBUILD_CFLAGS-$(call gcc-min-version, 90100) += -Wno-alloc-size-larger-than
1070KBUILD_CFLAGS += $(KBUILD_CFLAGS-y) $(CONFIG_CC_IMPLICIT_FALLTHROUGH)
1071
1072# disable invalid "can't wrap" optimizations for signed / pointers
1073KBUILD_CFLAGS	+= -fno-strict-overflow
1074
1075# Make sure -fstack-check isn't enabled (like gentoo apparently did)
1076KBUILD_CFLAGS  += -fno-stack-check
1077
1078# conserve stack if available
1079ifdef CONFIG_CC_IS_GCC
1080KBUILD_CFLAGS   += -fconserve-stack
1081endif
1082
1083# Prohibit date/time macros, which would make the build non-deterministic
1084KBUILD_CFLAGS   += -Werror=date-time
1085
1086# enforce correct pointer usage
1087KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
1088
1089# Require designated initializers for all marked structures
1090KBUILD_CFLAGS   += $(call cc-option,-Werror=designated-init)
1091
1092# change __FILE__ to the relative path from the srctree
1093KBUILD_CPPFLAGS += $(call cc-option,-fmacro-prefix-map=$(srctree)/=)
1094
1095# include additional Makefiles when needed
1096include-y			:= scripts/Makefile.extrawarn
1097include-$(CONFIG_DEBUG_INFO)	+= scripts/Makefile.debug
1098include-$(CONFIG_KASAN)		+= scripts/Makefile.kasan
1099include-$(CONFIG_KCSAN)		+= scripts/Makefile.kcsan
1100include-$(CONFIG_KMSAN)		+= scripts/Makefile.kmsan
1101include-$(CONFIG_UBSAN)		+= scripts/Makefile.ubsan
1102include-$(CONFIG_KCOV)		+= scripts/Makefile.kcov
1103include-$(CONFIG_RANDSTRUCT)	+= scripts/Makefile.randstruct
1104include-$(CONFIG_GCC_PLUGINS)	+= scripts/Makefile.gcc-plugins
1105
1106include $(addprefix $(srctree)/, $(include-y))
1107
1108# scripts/Makefile.gcc-plugins is intentionally included last.
1109# Do not add $(call cc-option,...) below this line. When you build the kernel
1110# from the clean source tree, the GCC plugins do not exist at this point.
1111
1112# Add user supplied CPPFLAGS, AFLAGS, CFLAGS and RUSTFLAGS as the last assignments
1113KBUILD_CPPFLAGS += $(KCPPFLAGS)
1114KBUILD_AFLAGS   += $(KAFLAGS)
1115KBUILD_CFLAGS   += $(KCFLAGS)
1116KBUILD_RUSTFLAGS += $(KRUSTFLAGS)
1117
1118KBUILD_LDFLAGS_MODULE += --build-id=sha1
1119LDFLAGS_vmlinux += --build-id=sha1
1120
1121KBUILD_LDFLAGS	+= -z noexecstack
1122ifeq ($(CONFIG_LD_IS_BFD),y)
1123KBUILD_LDFLAGS	+= $(call ld-option,--no-warn-rwx-segments)
1124endif
1125
1126ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
1127LDFLAGS_vmlinux	+= -X
1128endif
1129
1130ifeq ($(CONFIG_RELR),y)
1131LDFLAGS_vmlinux	+= --pack-dyn-relocs=relr --use-android-relr-tags
1132endif
1133
1134# We never want expected sections to be placed heuristically by the
1135# linker. All sections should be explicitly named in the linker script.
1136ifdef CONFIG_LD_ORPHAN_WARN
1137LDFLAGS_vmlinux += --orphan-handling=$(CONFIG_LD_ORPHAN_WARN_LEVEL)
1138endif
1139
1140# Align the bit size of userspace programs with the kernel
1141KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1142KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
1143
1144# make the checker run with the right architecture
1145CHECKFLAGS += --arch=$(ARCH)
1146
1147# insure the checker run with the right endianness
1148CHECKFLAGS += $(if $(CONFIG_CPU_BIG_ENDIAN),-mbig-endian,-mlittle-endian)
1149
1150# the checker needs the correct machine size
1151CHECKFLAGS += $(if $(CONFIG_64BIT),-m64,-m32)
1152
1153# Default kernel image to build when no specific target is given.
1154# KBUILD_IMAGE may be overruled on the command line or
1155# set in the environment
1156# Also any assignments in arch/$(ARCH)/Makefile take precedence over
1157# this default value
1158export KBUILD_IMAGE ?= vmlinux
1159
1160#
1161# INSTALL_PATH specifies where to place the updated kernel and system map
1162# images. Default is /boot, but you can set it to other values
1163export	INSTALL_PATH ?= /boot
1164
1165#
1166# INSTALL_DTBS_PATH specifies a prefix for relocations required by build roots.
1167# Like INSTALL_MOD_PATH, it isn't defined in the Makefile, but can be passed as
1168# an argument if needed. Otherwise it defaults to the kernel install path
1169#
1170export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE)
1171
1172#
1173# INSTALL_MOD_PATH specifies a prefix to MODLIB for module directory
1174# relocations required by build roots.  This is not defined in the
1175# makefile but the argument can be passed to make if needed.
1176#
1177
1178MODLIB	= $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE)
1179export MODLIB
1180
1181PHONY += prepare0
1182
1183export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
1184export MODORDER := $(extmod_prefix)modules.order
1185export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
1186
1187ifeq ($(KBUILD_EXTMOD),)
1188
1189build-dir	:= .
1190clean-dirs	:= $(sort . Documentation \
1191		     $(patsubst %/,%,$(filter %/, $(core-) \
1192			$(drivers-) $(libs-))))
1193
1194export ARCH_CORE	:= $(core-y)
1195export ARCH_LIB		:= $(filter %/, $(libs-y))
1196export ARCH_DRIVERS	:= $(drivers-y) $(drivers-m)
1197# Externally visible symbols (used by link-vmlinux.sh)
1198
1199KBUILD_VMLINUX_OBJS := ./built-in.a
1200ifdef CONFIG_MODULES
1201KBUILD_VMLINUX_OBJS += $(patsubst %/, %/lib.a, $(filter %/, $(libs-y)))
1202KBUILD_VMLINUX_LIBS := $(filter-out %/, $(libs-y))
1203else
1204KBUILD_VMLINUX_LIBS := $(patsubst %/,%/lib.a, $(libs-y))
1205endif
1206
1207export KBUILD_VMLINUX_LIBS
1208export KBUILD_LDS          := arch/$(SRCARCH)/kernel/vmlinux.lds
1209
1210# Recurse until adjust_autoksyms.sh is satisfied
1211PHONY += autoksyms_recursive
1212ifdef CONFIG_TRIM_UNUSED_KSYMS
1213# For the kernel to actually contain only the needed exported symbols,
1214# we have to build modules as well to determine what those symbols are.
1215# (this can be evaluated only once include/config/auto.conf has been included)
1216KBUILD_MODULES := 1
1217
1218autoksyms_recursive: $(build-dir) modules.order
1219	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/adjust_autoksyms.sh \
1220	  "$(MAKE) -f $(srctree)/Makefile autoksyms_recursive"
1221endif
1222
1223autoksyms_h := $(if $(CONFIG_TRIM_UNUSED_KSYMS), include/generated/autoksyms.h)
1224
1225quiet_cmd_autoksyms_h = GEN     $@
1226      cmd_autoksyms_h = mkdir -p $(dir $@); \
1227			$(CONFIG_SHELL) $(srctree)/scripts/gen_autoksyms.sh $@
1228
1229$(autoksyms_h):
1230	$(call cmd,autoksyms_h)
1231
1232# '$(AR) mPi' needs 'T' to workaround the bug of llvm-ar <= 14
1233quiet_cmd_ar_vmlinux.a = AR      $@
1234      cmd_ar_vmlinux.a = \
1235	rm -f $@; \
1236	$(AR) cDPrST $@ $(KBUILD_VMLINUX_OBJS); \
1237	$(AR) mPiT $$($(AR) t $@ | sed -n 1p) $@ $$($(AR) t $@ | grep -F -f $(srctree)/scripts/head-object-list.txt)
1238
1239targets += vmlinux.a
1240vmlinux.a: $(KBUILD_VMLINUX_OBJS) scripts/head-object-list.txt autoksyms_recursive FORCE
1241	$(call if_changed,ar_vmlinux.a)
1242
1243PHONY += vmlinux_o
1244vmlinux_o: vmlinux.a $(KBUILD_VMLINUX_LIBS)
1245	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux_o
1246
1247vmlinux.o modules.builtin.modinfo modules.builtin: vmlinux_o
1248	@:
1249
1250PHONY += vmlinux
1251vmlinux: vmlinux.o $(KBUILD_LDS) modpost
1252	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.vmlinux
1253
1254# The actual objects are generated when descending,
1255# make sure no implicit rule kicks in
1256$(sort $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)): . ;
1257
1258filechk_kernel.release = \
1259	echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
1260
1261# Store (new) KERNELRELEASE string in include/config/kernel.release
1262include/config/kernel.release: FORCE
1263	$(call filechk,kernel.release)
1264
1265# Additional helpers built in scripts/
1266# Carefully list dependencies so we do not try to build scripts twice
1267# in parallel
1268PHONY += scripts
1269scripts: scripts_basic scripts_dtc
1270	$(Q)$(MAKE) $(build)=$(@)
1271
1272# Things we need to do before we recursively start building the kernel
1273# or the modules are listed in "prepare".
1274# A multi level approach is used. prepareN is processed before prepareN-1.
1275# archprepare is used in arch Makefiles and when processed asm symlink,
1276# version.h and scripts_basic is processed / created.
1277
1278PHONY += prepare archprepare
1279
1280archprepare: outputmakefile archheaders archscripts scripts include/config/kernel.release \
1281	asm-generic $(version_h) $(autoksyms_h) include/generated/utsrelease.h \
1282	include/generated/compile.h include/generated/autoconf.h remove-stale-files
1283
1284prepare0: archprepare
1285	$(Q)$(MAKE) $(build)=scripts/mod
1286	$(Q)$(MAKE) $(build)=. prepare
1287
1288# All the preparing..
1289prepare: prepare0
1290ifdef CONFIG_RUST
1291	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v
1292	$(Q)$(MAKE) $(build)=rust
1293endif
1294
1295PHONY += remove-stale-files
1296remove-stale-files:
1297	$(Q)$(srctree)/scripts/remove-stale-files
1298
1299# Support for using generic headers in asm-generic
1300asm-generic := -f $(srctree)/scripts/Makefile.asm-generic obj
1301
1302PHONY += asm-generic uapi-asm-generic
1303asm-generic: uapi-asm-generic
1304	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/asm \
1305	generic=include/asm-generic
1306uapi-asm-generic:
1307	$(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \
1308	generic=include/uapi/asm-generic
1309
1310# Generate some files
1311# ---------------------------------------------------------------------------
1312
1313# KERNELRELEASE can change from a few different places, meaning version.h
1314# needs to be updated, so this check is forced on all builds
1315
1316uts_len := 64
1317define filechk_utsrelease.h
1318	if [ `echo -n "$(KERNELRELEASE)" | wc -c ` -gt $(uts_len) ]; then \
1319	  echo '"$(KERNELRELEASE)" exceeds $(uts_len) characters' >&2;    \
1320	  exit 1;                                                         \
1321	fi;                                                               \
1322	echo \#define UTS_RELEASE \"$(KERNELRELEASE)\"
1323endef
1324
1325define filechk_version.h
1326	if [ $(SUBLEVEL) -gt 255 ]; then                                 \
1327		echo \#define LINUX_VERSION_CODE $(shell                 \
1328		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + 255); \
1329	else                                                             \
1330		echo \#define LINUX_VERSION_CODE $(shell                 \
1331		expr $(VERSION) \* 65536 + $(PATCHLEVEL) \* 256 + $(SUBLEVEL)); \
1332	fi;                                                              \
1333	echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) +  \
1334	((c) > 255 ? 255 : (c)))';                                       \
1335	echo \#define LINUX_VERSION_MAJOR $(VERSION);                    \
1336	echo \#define LINUX_VERSION_PATCHLEVEL $(PATCHLEVEL);            \
1337	echo \#define LINUX_VERSION_SUBLEVEL $(SUBLEVEL)
1338endef
1339
1340$(version_h): PATCHLEVEL := $(or $(PATCHLEVEL), 0)
1341$(version_h): SUBLEVEL := $(or $(SUBLEVEL), 0)
1342$(version_h): FORCE
1343	$(call filechk,version.h)
1344
1345include/generated/utsrelease.h: include/config/kernel.release FORCE
1346	$(call filechk,utsrelease.h)
1347
1348filechk_compile.h = $(srctree)/scripts/mkcompile_h \
1349	"$(UTS_MACHINE)" "$(CONFIG_CC_VERSION_TEXT)" "$(LD)"
1350
1351include/generated/compile.h: FORCE
1352	$(call filechk,compile.h)
1353
1354PHONY += headerdep
1355headerdep:
1356	$(Q)find $(srctree)/include/ -name '*.h' | xargs --max-args 1 \
1357	$(srctree)/scripts/headerdep.pl -I$(srctree)/include
1358
1359# ---------------------------------------------------------------------------
1360# Kernel headers
1361
1362#Default location for installed headers
1363export INSTALL_HDR_PATH = $(objtree)/usr
1364
1365quiet_cmd_headers_install = INSTALL $(INSTALL_HDR_PATH)/include
1366      cmd_headers_install = \
1367	mkdir -p $(INSTALL_HDR_PATH); \
1368	rsync -mrl --include='*/' --include='*\.h' --exclude='*' \
1369	usr/include $(INSTALL_HDR_PATH)
1370
1371PHONY += headers_install
1372headers_install: headers
1373	$(call cmd,headers_install)
1374
1375PHONY += archheaders archscripts
1376
1377hdr-inst := -f $(srctree)/scripts/Makefile.headersinst obj
1378
1379PHONY += headers
1380headers: $(version_h) scripts_unifdef uapi-asm-generic archheaders archscripts
1381	$(if $(filter um, $(SRCARCH)), $(error Headers not exportable for UML))
1382	$(Q)$(MAKE) $(hdr-inst)=include/uapi
1383	$(Q)$(MAKE) $(hdr-inst)=arch/$(SRCARCH)/include/uapi
1384
1385ifdef CONFIG_HEADERS_INSTALL
1386prepare: headers
1387endif
1388
1389PHONY += scripts_unifdef
1390scripts_unifdef: scripts_basic
1391	$(Q)$(MAKE) $(build)=scripts scripts/unifdef
1392
1393# ---------------------------------------------------------------------------
1394# Install
1395
1396# Many distributions have the custom install script, /sbin/installkernel.
1397# If DKMS is installed, 'make install' will eventually recurse back
1398# to this Makefile to build and install external modules.
1399# Cancel sub_make_done so that options such as M=, V=, etc. are parsed.
1400
1401quiet_cmd_install = INSTALL $(INSTALL_PATH)
1402      cmd_install = unset sub_make_done; $(srctree)/scripts/install.sh
1403
1404# ---------------------------------------------------------------------------
1405# Tools
1406
1407ifdef CONFIG_OBJTOOL
1408prepare: tools/objtool
1409endif
1410
1411ifdef CONFIG_BPF
1412ifdef CONFIG_DEBUG_INFO_BTF
1413prepare: tools/bpf/resolve_btfids
1414endif
1415endif
1416
1417PHONY += resolve_btfids_clean
1418
1419resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids
1420
1421# tools/bpf/resolve_btfids directory might not exist
1422# in output directory, skip its clean in that case
1423resolve_btfids_clean:
1424ifneq ($(wildcard $(resolve_btfids_O)),)
1425	$(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean
1426endif
1427
1428# Clear a bunch of variables before executing the submake
1429ifeq ($(quiet),silent_)
1430tools_silent=s
1431endif
1432
1433tools/: FORCE
1434	$(Q)mkdir -p $(objtree)/tools
1435	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/
1436
1437tools/%: FORCE
1438	$(Q)mkdir -p $(objtree)/tools
1439	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(srctree)/tools/ $*
1440
1441# ---------------------------------------------------------------------------
1442# Kernel selftest
1443
1444PHONY += kselftest
1445kselftest: headers
1446	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
1447
1448kselftest-%: headers FORCE
1449	$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests $*
1450
1451PHONY += kselftest-merge
1452kselftest-merge:
1453	$(if $(wildcard $(objtree)/.config),, $(error No .config exists, config your kernel first!))
1454	$(Q)find $(srctree)/tools/testing/selftests -name config | \
1455		xargs $(srctree)/scripts/kconfig/merge_config.sh -m $(objtree)/.config
1456	$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
1457
1458# ---------------------------------------------------------------------------
1459# Devicetree files
1460
1461ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
1462dtstree := arch/$(SRCARCH)/boot/dts
1463endif
1464
1465ifneq ($(dtstree),)
1466
1467%.dtb: dtbs_prepare
1468	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1469
1470%.dtbo: dtbs_prepare
1471	$(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
1472
1473PHONY += dtbs dtbs_prepare dtbs_install dtbs_check
1474dtbs: dtbs_prepare
1475	$(Q)$(MAKE) $(build)=$(dtstree)
1476
1477# include/config/kernel.release is actually needed when installing DTBs because
1478# INSTALL_DTBS_PATH contains $(KERNELRELEASE). However, we do not want to make
1479# dtbs_install depend on it as dtbs_install may run as root.
1480dtbs_prepare: include/config/kernel.release scripts_dtc
1481
1482ifneq ($(filter dtbs_check, $(MAKECMDGOALS)),)
1483export CHECK_DTBS=y
1484dtbs: dt_binding_check
1485endif
1486
1487dtbs_check: dtbs
1488
1489dtbs_install:
1490	$(Q)$(MAKE) $(dtbinst)=$(dtstree) dst=$(INSTALL_DTBS_PATH)
1491
1492ifdef CONFIG_OF_EARLY_FLATTREE
1493all: dtbs
1494endif
1495
1496endif
1497
1498PHONY += scripts_dtc
1499scripts_dtc: scripts_basic
1500	$(Q)$(MAKE) $(build)=scripts/dtc
1501
1502ifneq ($(filter dt_binding_check, $(MAKECMDGOALS)),)
1503export CHECK_DT_BINDING=y
1504endif
1505
1506PHONY += dt_binding_check
1507dt_binding_check: scripts_dtc
1508	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings
1509
1510PHONY += dt_compatible_check
1511dt_compatible_check: dt_binding_check
1512	$(Q)$(MAKE) $(build)=Documentation/devicetree/bindings $@
1513
1514# ---------------------------------------------------------------------------
1515# Modules
1516
1517ifdef CONFIG_MODULES
1518
1519# By default, build modules as well
1520
1521all: modules
1522
1523# When we're building modules with modversions, we need to consider
1524# the built-in objects during the descend as well, in order to
1525# make sure the checksums are up to date before we record them.
1526ifdef CONFIG_MODVERSIONS
1527  KBUILD_BUILTIN := 1
1528endif
1529
1530# Build modules
1531#
1532
1533# *.ko are usually independent of vmlinux, but CONFIG_DEBUG_INFOBTF_MODULES
1534# is an exception.
1535ifdef CONFIG_DEBUG_INFO_BTF_MODULES
1536modules: vmlinux
1537endif
1538
1539modules: modules_prepare
1540
1541# Target to prepare building external modules
1542modules_prepare: prepare
1543	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
1544
1545export modules_sign_only :=
1546
1547ifeq ($(CONFIG_MODULE_SIG),y)
1548PHONY += modules_sign
1549modules_sign: modules_install
1550	@:
1551
1552# modules_sign is a subset of modules_install.
1553# 'make modules_install modules_sign' is equivalent to 'make modules_install'.
1554ifeq ($(filter modules_install,$(MAKECMDGOALS)),)
1555modules_sign_only := y
1556endif
1557endif
1558
1559modinst_pre :=
1560ifneq ($(filter modules_install,$(MAKECMDGOALS)),)
1561modinst_pre := __modinst_pre
1562endif
1563
1564modules_install: $(modinst_pre)
1565PHONY += __modinst_pre
1566__modinst_pre:
1567	@rm -rf $(MODLIB)/kernel
1568	@rm -f $(MODLIB)/source
1569	@mkdir -p $(MODLIB)/kernel
1570	@ln -s $(abspath $(srctree)) $(MODLIB)/source
1571	@if [ ! $(objtree) -ef  $(MODLIB)/build ]; then \
1572		rm -f $(MODLIB)/build ; \
1573		ln -s $(CURDIR) $(MODLIB)/build ; \
1574	fi
1575	@sed 's:^\(.*\)\.o$$:kernel/\1.ko:' modules.order > $(MODLIB)/modules.order
1576	@cp -f modules.builtin $(MODLIB)/
1577	@cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
1578
1579endif # CONFIG_MODULES
1580
1581###
1582# Cleaning is done on three levels.
1583# make clean     Delete most generated files
1584#                Leave enough to build external modules
1585# make mrproper  Delete the current configuration, and all generated files
1586# make distclean Remove editor backup files, patch leftover files and the like
1587
1588# Directories & files removed with 'make clean'
1589CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
1590	       modules.builtin modules.builtin.modinfo modules.nsdeps \
1591	       compile_commands.json .thinlto-cache rust/test rust/doc \
1592	       .vmlinux.objs .vmlinux.export.c
1593
1594# Directories & files removed with 'make mrproper'
1595MRPROPER_FILES += include/config include/generated          \
1596		  arch/$(SRCARCH)/include/generated .objdiff \
1597		  debian snap tar-install \
1598		  .config .config.old .version \
1599		  Module.symvers \
1600		  certs/signing_key.pem \
1601		  certs/x509.genkey \
1602		  vmlinux-gdb.py \
1603		  *.spec \
1604		  rust/target.json rust/libmacros.so
1605
1606# clean - Delete most, but leave enough to build external modules
1607#
1608clean: rm-files := $(CLEAN_FILES)
1609
1610PHONY += archclean vmlinuxclean
1611
1612vmlinuxclean:
1613	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/link-vmlinux.sh clean
1614	$(Q)$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) clean)
1615
1616clean: archclean vmlinuxclean resolve_btfids_clean
1617
1618# mrproper - Delete all generated files, including .config
1619#
1620mrproper: rm-files := $(wildcard $(MRPROPER_FILES))
1621mrproper-dirs      := $(addprefix _mrproper_,scripts)
1622
1623PHONY += $(mrproper-dirs) mrproper
1624$(mrproper-dirs):
1625	$(Q)$(MAKE) $(clean)=$(patsubst _mrproper_%,%,$@)
1626
1627mrproper: clean $(mrproper-dirs)
1628	$(call cmd,rmfiles)
1629	@find . $(RCS_FIND_IGNORE) \
1630		\( -name '*.rmeta' \) \
1631		-type f -print | xargs rm -f
1632
1633# distclean
1634#
1635PHONY += distclean
1636
1637distclean: mrproper
1638	@find . $(RCS_FIND_IGNORE) \
1639		\( -name '*.orig' -o -name '*.rej' -o -name '*~' \
1640		-o -name '*.bak' -o -name '#*#' -o -name '*%' \
1641		-o -name 'core' -o -name tags -o -name TAGS -o -name 'cscope*' \
1642		-o -name GPATH -o -name GRTAGS -o -name GSYMS -o -name GTAGS \) \
1643		-type f -print | xargs rm -f
1644
1645
1646# Packaging of the kernel to various formats
1647# ---------------------------------------------------------------------------
1648
1649%src-pkg: FORCE
1650	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1651%pkg: include/config/kernel.release FORCE
1652	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.package $@
1653
1654# Brief documentation of the typical targets used
1655# ---------------------------------------------------------------------------
1656
1657boards := $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*_defconfig)
1658boards := $(sort $(notdir $(boards)))
1659board-dirs := $(dir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/*/*_defconfig))
1660board-dirs := $(sort $(notdir $(board-dirs:/=)))
1661
1662PHONY += help
1663help:
1664	@echo  'Cleaning targets:'
1665	@echo  '  clean		  - Remove most generated files but keep the config and'
1666	@echo  '                    enough build support to build external modules'
1667	@echo  '  mrproper	  - Remove all generated files + config + various backup files'
1668	@echo  '  distclean	  - mrproper + remove editor backup and patch files'
1669	@echo  ''
1670	@echo  'Configuration targets:'
1671	@$(MAKE) -f $(srctree)/scripts/kconfig/Makefile help
1672	@echo  ''
1673	@echo  'Other generic targets:'
1674	@echo  '  all		  - Build all targets marked with [*]'
1675	@echo  '* vmlinux	  - Build the bare kernel'
1676	@echo  '* modules	  - Build all modules'
1677	@echo  '  modules_install - Install all modules to INSTALL_MOD_PATH (default: /)'
1678	@echo  '  dir/            - Build all files in dir and below'
1679	@echo  '  dir/file.[ois]  - Build specified target only'
1680	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1681	@echo  '                    (requires compiler support for LLVM assembly generation)'
1682	@echo  '  dir/file.lst    - Build specified mixed source/assembly target only'
1683	@echo  '                    (requires a recent binutils and recent build (System.map))'
1684	@echo  '  dir/file.ko     - Build module including final link'
1685	@echo  '  modules_prepare - Set up for building external modules'
1686	@echo  '  tags/TAGS	  - Generate tags file for editors'
1687	@echo  '  cscope	  - Generate cscope index'
1688	@echo  '  gtags           - Generate GNU GLOBAL index'
1689	@echo  '  kernelrelease	  - Output the release version string (use with make -s)'
1690	@echo  '  kernelversion	  - Output the version stored in Makefile (use with make -s)'
1691	@echo  '  image_name	  - Output the image name (use with make -s)'
1692	@echo  '  headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH'; \
1693	 echo  '                    (default: $(INSTALL_HDR_PATH))'; \
1694	 echo  ''
1695	@echo  'Static analysers:'
1696	@echo  '  checkstack      - Generate a list of stack hogs'
1697	@echo  '  versioncheck    - Sanity check on version.h usage'
1698	@echo  '  includecheck    - Check for duplicate included header files'
1699	@echo  '  export_report   - List the usages of all exported symbols'
1700	@echo  '  headerdep       - Detect inclusion cycles in headers'
1701	@echo  '  coccicheck      - Check with Coccinelle'
1702	@echo  '  clang-analyzer  - Check with clang static analyzer'
1703	@echo  '  clang-tidy      - Check with clang-tidy'
1704	@echo  ''
1705	@echo  'Tools:'
1706	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
1707	@echo  ''
1708	@echo  'Kernel selftest:'
1709	@echo  '  kselftest         - Build and run kernel selftest'
1710	@echo  '                      Build, install, and boot kernel before'
1711	@echo  '                      running kselftest on it'
1712	@echo  '                      Run as root for full coverage'
1713	@echo  '  kselftest-all     - Build kernel selftest'
1714	@echo  '  kselftest-install - Build and install kernel selftest'
1715	@echo  '  kselftest-clean   - Remove all generated kselftest files'
1716	@echo  '  kselftest-merge   - Merge all the config dependencies of'
1717	@echo  '		      kselftest to existing .config.'
1718	@echo  ''
1719	@echo  'Rust targets:'
1720	@echo  '  rustavailable   - Checks whether the Rust toolchain is'
1721	@echo  '		    available and, if not, explains why.'
1722	@echo  '  rustfmt	  - Reformat all the Rust code in the kernel'
1723	@echo  '  rustfmtcheck	  - Checks if all the Rust code in the kernel'
1724	@echo  '		    is formatted, printing a diff otherwise.'
1725	@echo  '  rustdoc	  - Generate Rust documentation'
1726	@echo  '		    (requires kernel .config)'
1727	@echo  '  rusttest        - Runs the Rust tests'
1728	@echo  '                    (requires kernel .config; downloads external repos)'
1729	@echo  '  rust-analyzer	  - Generate rust-project.json rust-analyzer support file'
1730	@echo  '		    (requires kernel .config)'
1731	@echo  '  dir/file.[os]   - Build specified target only'
1732	@echo  '  dir/file.rsi    - Build macro expanded source, similar to C preprocessing.'
1733	@echo  '                    Run with RUSTFMT=n to skip reformatting if needed.'
1734	@echo  '                    The output is not intended to be compilable.'
1735	@echo  '  dir/file.ll     - Build the LLVM assembly file'
1736	@echo  ''
1737	@$(if $(dtstree), \
1738		echo 'Devicetree:'; \
1739		echo '* dtbs             - Build device tree blobs for enabled boards'; \
1740		echo '  dtbs_install     - Install dtbs to $(INSTALL_DTBS_PATH)'; \
1741		echo '  dt_binding_check - Validate device tree binding documents'; \
1742		echo '  dtbs_check       - Validate device tree source files';\
1743		echo '')
1744
1745	@echo 'Userspace tools targets:'
1746	@echo '  use "make tools/help"'
1747	@echo '  or  "cd tools; make help"'
1748	@echo  ''
1749	@echo  'Kernel packaging:'
1750	@$(MAKE) -f $(srctree)/scripts/Makefile.package help
1751	@echo  ''
1752	@echo  'Documentation targets:'
1753	@$(MAKE) -f $(srctree)/Documentation/Makefile dochelp
1754	@echo  ''
1755	@echo  'Architecture specific targets ($(SRCARCH)):'
1756	@$(or $(archhelp),\
1757		echo '  No architecture specific help defined for $(SRCARCH)')
1758	@echo  ''
1759	@$(if $(boards), \
1760		$(foreach b, $(boards), \
1761		printf "  %-27s - Build for %s\\n" $(b) $(subst _defconfig,,$(b));) \
1762		echo '')
1763	@$(if $(board-dirs), \
1764		$(foreach b, $(board-dirs), \
1765		printf "  %-16s - Show %s-specific targets\\n" help-$(b) $(b);) \
1766		printf "  %-16s - Show all of the above\\n" help-boards; \
1767		echo '')
1768
1769	@echo  '  make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build'
1770	@echo  '  make V=2   [targets] 2 => give reason for rebuild of target'
1771	@echo  '  make O=dir [targets] Locate all output files in "dir", including .config'
1772	@echo  '  make C=1   [targets] Check re-compiled c source with $$CHECK'
1773	@echo  '                       (sparse by default)'
1774	@echo  '  make C=2   [targets] Force check of all c source with $$CHECK'
1775	@echo  '  make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections'
1776	@echo  '  make W=n   [targets] Enable extra build checks, n=1,2,3 where'
1777	@echo  '		1: warnings which may be relevant and do not occur too often'
1778	@echo  '		2: warnings which occur quite often but may still be relevant'
1779	@echo  '		3: more obscure warnings, can most likely be ignored'
1780	@echo  '		e: warnings are being treated as errors'
1781	@echo  '		Multiple levels can be combined with W=12 or W=123'
1782	@echo  ''
1783	@echo  'Execute "make" or "make all" to build all targets marked with [*] '
1784	@echo  'For further info see the ./README file'
1785
1786
1787help-board-dirs := $(addprefix help-,$(board-dirs))
1788
1789help-boards: $(help-board-dirs)
1790
1791boards-per-dir = $(sort $(notdir $(wildcard $(srctree)/arch/$(SRCARCH)/configs/$*/*_defconfig)))
1792
1793$(help-board-dirs): help-%:
1794	@echo  'Architecture specific targets ($(SRCARCH) $*):'
1795	@$(if $(boards-per-dir), \
1796		$(foreach b, $(boards-per-dir), \
1797		printf "  %-24s - Build for %s\\n" $*/$(b) $(subst _defconfig,,$(b));) \
1798		echo '')
1799
1800
1801# Documentation targets
1802# ---------------------------------------------------------------------------
1803DOC_TARGETS := xmldocs latexdocs pdfdocs htmldocs epubdocs cleandocs \
1804	       linkcheckdocs dochelp refcheckdocs texinfodocs infodocs
1805PHONY += $(DOC_TARGETS)
1806$(DOC_TARGETS):
1807	$(Q)$(MAKE) $(build)=Documentation $@
1808
1809
1810# Rust targets
1811# ---------------------------------------------------------------------------
1812
1813# "Is Rust available?" target
1814PHONY += rustavailable
1815rustavailable:
1816	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/rust_is_available.sh -v && echo "Rust is available!"
1817
1818# Documentation target
1819#
1820# Using the singular to avoid running afoul of `no-dot-config-targets`.
1821PHONY += rustdoc
1822rustdoc: prepare
1823	$(Q)$(MAKE) $(build)=rust $@
1824
1825# Testing target
1826PHONY += rusttest
1827rusttest: prepare
1828	$(Q)$(MAKE) $(build)=rust $@
1829
1830# Formatting targets
1831PHONY += rustfmt rustfmtcheck
1832
1833# We skip `rust/alloc` since we want to minimize the diff w.r.t. upstream.
1834#
1835# We match using absolute paths since `find` does not resolve them
1836# when matching, which is a problem when e.g. `srctree` is `..`.
1837# We `grep` afterwards in order to remove the directory entry itself.
1838rustfmt:
1839	$(Q)find $(abs_srctree) -type f -name '*.rs' \
1840		-o -path $(abs_srctree)/rust/alloc -prune \
1841		-o -path $(abs_objtree)/rust/test -prune \
1842		| grep -Fv $(abs_srctree)/rust/alloc \
1843		| grep -Fv $(abs_objtree)/rust/test \
1844		| grep -Fv generated \
1845		| xargs $(RUSTFMT) $(rustfmt_flags)
1846
1847rustfmtcheck: rustfmt_flags = --check
1848rustfmtcheck: rustfmt
1849
1850# IDE support targets
1851PHONY += rust-analyzer
1852rust-analyzer:
1853	$(Q)$(MAKE) $(build)=rust $@
1854
1855# Misc
1856# ---------------------------------------------------------------------------
1857
1858PHONY += scripts_gdb
1859scripts_gdb: prepare0
1860	$(Q)$(MAKE) $(build)=scripts/gdb
1861	$(Q)ln -fsn $(abspath $(srctree)/scripts/gdb/vmlinux-gdb.py)
1862
1863ifdef CONFIG_GDB_SCRIPTS
1864all: scripts_gdb
1865endif
1866
1867else # KBUILD_EXTMOD
1868
1869###
1870# External module support.
1871# When building external modules the kernel used as basis is considered
1872# read-only, and no consistency checks are made and the make
1873# system is not used on the basis kernel. If updates are required
1874# in the basis kernel ordinary make commands (without M=...) must be used.
1875
1876# We are always building only modules.
1877KBUILD_BUILTIN :=
1878KBUILD_MODULES := 1
1879
1880build-dir := $(KBUILD_EXTMOD)
1881
1882compile_commands.json: $(extmod_prefix)compile_commands.json
1883PHONY += compile_commands.json
1884
1885clean-dirs := $(KBUILD_EXTMOD)
1886clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
1887	$(KBUILD_EXTMOD)/compile_commands.json $(KBUILD_EXTMOD)/.thinlto-cache
1888
1889PHONY += prepare
1890# now expand this into a simple variable to reduce the cost of shell evaluations
1891prepare: CC_VERSION_TEXT := $(CC_VERSION_TEXT)
1892prepare:
1893	@if [ "$(CC_VERSION_TEXT)" != "$(CONFIG_CC_VERSION_TEXT)" ]; then \
1894		echo >&2 "warning: the compiler differs from the one used to build the kernel"; \
1895		echo >&2 "  The kernel was built by: $(CONFIG_CC_VERSION_TEXT)"; \
1896		echo >&2 "  You are using:           $(CC_VERSION_TEXT)"; \
1897	fi
1898
1899PHONY += help
1900help:
1901	@echo  '  Building external modules.'
1902	@echo  '  Syntax: make -C path/to/kernel/src M=$$PWD target'
1903	@echo  ''
1904	@echo  '  modules         - default target, build the module(s)'
1905	@echo  '  modules_install - install the module'
1906	@echo  '  clean           - remove generated files in module directory only'
1907	@echo  ''
1908
1909endif # KBUILD_EXTMOD
1910
1911# ---------------------------------------------------------------------------
1912# Modules
1913
1914PHONY += modules modules_install modules_prepare
1915
1916ifdef CONFIG_MODULES
1917
1918$(MODORDER): $(build-dir)
1919	@:
1920
1921# KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules.
1922# This is solely useful to speed up test compiles.
1923modules: modpost
1924ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1925	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1926endif
1927
1928PHONY += modules_check
1929modules_check: $(MODORDER)
1930	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/modules-check.sh $<
1931
1932quiet_cmd_depmod = DEPMOD  $(MODLIB)
1933      cmd_depmod = $(CONFIG_SHELL) $(srctree)/scripts/depmod.sh $(DEPMOD) \
1934                   $(KERNELRELEASE)
1935
1936modules_install:
1937	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
1938	$(call cmd,depmod)
1939
1940else # CONFIG_MODULES
1941
1942# Modules not configured
1943# ---------------------------------------------------------------------------
1944
1945modules modules_install:
1946	@echo >&2 '***'
1947	@echo >&2 '*** The present kernel configuration has modules disabled.'
1948	@echo >&2 '*** To use the module feature, please run "make menuconfig" etc.'
1949	@echo >&2 '*** to enable CONFIG_MODULES.'
1950	@echo >&2 '***'
1951	@exit 1
1952
1953KBUILD_MODULES :=
1954
1955endif # CONFIG_MODULES
1956
1957PHONY += modpost
1958modpost: $(if $(single-build),, $(if $(KBUILD_BUILTIN), vmlinux.o)) \
1959	 $(if $(KBUILD_MODULES), modules_check)
1960	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1961
1962# Single targets
1963# ---------------------------------------------------------------------------
1964# To build individual files in subdirectories, you can do like this:
1965#
1966#   make foo/bar/baz.s
1967#
1968# The supported suffixes for single-target are listed in 'single-targets'
1969#
1970# To build only under specific subdirectories, you can do like this:
1971#
1972#   make foo/bar/baz/
1973
1974ifdef single-build
1975
1976# .ko is special because modpost is needed
1977single-ko := $(sort $(filter %.ko, $(MAKECMDGOALS)))
1978single-no-ko := $(filter-out $(single-ko), $(MAKECMDGOALS)) \
1979		$(foreach x, o mod, $(patsubst %.ko, %.$x, $(single-ko)))
1980
1981$(single-ko): single_modules
1982	@:
1983$(single-no-ko): $(build-dir)
1984	@:
1985
1986# Remove MODORDER when done because it is not the real one.
1987PHONY += single_modules
1988single_modules: $(single-no-ko) modules_prepare
1989	$(Q){ $(foreach m, $(single-ko), echo $(extmod_prefix)$m;) } > $(MODORDER)
1990	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
1991ifneq ($(KBUILD_MODPOST_NOFINAL),1)
1992	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
1993endif
1994	$(Q)rm -f $(MODORDER)
1995
1996single-goals := $(addprefix $(build-dir)/, $(single-no-ko))
1997
1998KBUILD_MODULES := 1
1999
2000endif
2001
2002# Preset locale variables to speed up the build process. Limit locale
2003# tweaks to this spot to avoid wrong language settings when running
2004# make menuconfig etc.
2005# Error messages still appears in the original language
2006PHONY += $(build-dir)
2007$(build-dir): prepare
2008	$(Q)$(MAKE) $(build)=$@ need-builtin=1 need-modorder=1 $(single-goals)
2009
2010clean-dirs := $(addprefix _clean_, $(clean-dirs))
2011PHONY += $(clean-dirs) clean
2012$(clean-dirs):
2013	$(Q)$(MAKE) $(clean)=$(patsubst _clean_%,%,$@)
2014
2015clean: $(clean-dirs)
2016	$(call cmd,rmfiles)
2017	@find $(or $(KBUILD_EXTMOD), .) $(RCS_FIND_IGNORE) \
2018		\( -name '*.[aios]' -o -name '*.rsi' -o -name '*.ko' -o -name '.*.cmd' \
2019		-o -name '*.ko.*' \
2020		-o -name '*.dtb' -o -name '*.dtbo' \
2021		-o -name '*.dtb.S' -o -name '*.dtbo.S' \
2022		-o -name '*.dt.yaml' \
2023		-o -name '*.dwo' -o -name '*.lst' \
2024		-o -name '*.su' -o -name '*.mod' -o -name '*.usyms' \
2025		-o -name '.*.d' -o -name '.*.tmp' -o -name '*.mod.c' \
2026		-o -name '*.lex.c' -o -name '*.tab.[ch]' \
2027		-o -name '*.asn1.[ch]' \
2028		-o -name '*.symtypes' -o -name 'modules.order' \
2029		-o -name '.tmp_*' \
2030		-o -name '*.c.[012]*.*' \
2031		-o -name '*.ll' \
2032		-o -name '*.gcno' \
2033		-o -name '*.*.symversions' \) -type f -print | xargs rm -f
2034
2035# Generate tags for editors
2036# ---------------------------------------------------------------------------
2037quiet_cmd_tags = GEN     $@
2038      cmd_tags = $(BASH) $(srctree)/scripts/tags.sh $@
2039
2040tags TAGS cscope gtags: FORCE
2041	$(call cmd,tags)
2042
2043# Script to generate missing namespace dependencies
2044# ---------------------------------------------------------------------------
2045
2046PHONY += nsdeps
2047nsdeps: export KBUILD_NSDEPS=1
2048nsdeps: modules
2049	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
2050
2051# Clang Tooling
2052# ---------------------------------------------------------------------------
2053
2054quiet_cmd_gen_compile_commands = GEN     $@
2055      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
2056
2057$(extmod_prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
2058	$(if $(KBUILD_EXTMOD),, vmlinux.a $(KBUILD_VMLINUX_LIBS)) \
2059	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
2060	$(call if_changed,gen_compile_commands)
2061
2062targets += $(extmod_prefix)compile_commands.json
2063
2064PHONY += clang-tidy clang-analyzer
2065
2066ifdef CONFIG_CC_IS_CLANG
2067quiet_cmd_clang_tools = CHECK   $<
2068      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
2069
2070clang-tidy clang-analyzer: $(extmod_prefix)compile_commands.json
2071	$(call cmd,clang_tools)
2072else
2073clang-tidy clang-analyzer:
2074	@echo "$@ requires CC=clang" >&2
2075	@false
2076endif
2077
2078# Scripts to check various things for consistency
2079# ---------------------------------------------------------------------------
2080
2081PHONY += includecheck versioncheck coccicheck export_report
2082
2083includecheck:
2084	find $(srctree)/* $(RCS_FIND_IGNORE) \
2085		-name '*.[hcS]' -type f -print | sort \
2086		| xargs $(PERL) -w $(srctree)/scripts/checkincludes.pl
2087
2088versioncheck:
2089	find $(srctree)/* $(RCS_FIND_IGNORE) \
2090		-name '*.[hcS]' -type f -print | sort \
2091		| xargs $(PERL) -w $(srctree)/scripts/checkversion.pl
2092
2093coccicheck:
2094	$(Q)$(BASH) $(srctree)/scripts/$@
2095
2096export_report:
2097	$(PERL) $(srctree)/scripts/export_report.pl
2098
2099PHONY += checkstack kernelrelease kernelversion image_name
2100
2101# UML needs a little special treatment here.  It wants to use the host
2102# toolchain, so needs $(SUBARCH) passed to checkstack.pl.  Everyone
2103# else wants $(ARCH), including people doing cross-builds, which means
2104# that $(SUBARCH) doesn't work here.
2105ifeq ($(ARCH), um)
2106CHECKSTACK_ARCH := $(SUBARCH)
2107else
2108CHECKSTACK_ARCH := $(ARCH)
2109endif
2110checkstack:
2111	$(OBJDUMP) -d vmlinux $$(find . -name '*.ko') | \
2112	$(PERL) $(srctree)/scripts/checkstack.pl $(CHECKSTACK_ARCH)
2113
2114kernelrelease:
2115	@echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
2116
2117kernelversion:
2118	@echo $(KERNELVERSION)
2119
2120image_name:
2121	@echo $(KBUILD_IMAGE)
2122
2123quiet_cmd_rmfiles = $(if $(wildcard $(rm-files)),CLEAN   $(wildcard $(rm-files)))
2124      cmd_rmfiles = rm -rf $(rm-files)
2125
2126# read saved command lines for existing targets
2127existing-targets := $(wildcard $(sort $(targets)))
2128
2129-include $(foreach f,$(existing-targets),$(dir $(f)).$(notdir $(f)).cmd)
2130
2131endif # config-build
2132endif # mixed-build
2133endif # need-sub-make
2134
2135PHONY += FORCE
2136FORCE:
2137
2138# Declare the contents of the PHONY variable as phony.  We keep that
2139# information in a variable so we can use it in if_changed and friends.
2140.PHONY: $(PHONY)
2141