1 # SPDX-License-Identifier: GPL-2.0
2 # Backward compatibility
3 asflags-y += $(EXTRA_AFLAGS)
4 ccflags-y += $(EXTRA_CFLAGS)
5 cppflags-y += $(EXTRA_CPPFLAGS)
6 ldflags-y += $(EXTRA_LDFLAGS)
8 # flags that take effect in current and sub directories
9 KBUILD_AFLAGS += $(subdir-asflags-y)
10 KBUILD_CFLAGS += $(subdir-ccflags-y)
11 KBUILD_RUSTFLAGS += $(subdir-rustflags-y)
13 # Figure out what we need to build from the various variables
14 # ===========================================================================
16 # When an object is listed to be built compiled-in and modular,
17 # only build the compiled-in version
18 obj-m := $(filter-out $(obj-y),$(obj-m))
20 # Libraries are always collected in one lib file.
21 # Filter out objects already built-in
22 lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
24 # Subdirectories we need to descend into
25 subdir-ym := $(sort $(subdir-y) $(subdir-m) \
26 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
28 # Handle objects in subdirs:
29 # - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
31 # - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
33 # Generate modules.order to determine modorder. Unfortunately, we don't have
34 # information about ordering between -y and -m subdirs. Just put -y's first.
37 obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
39 obj-m := $(filter-out %/, $(obj-m))
43 obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
45 obj-y := $(filter-out %/, $(obj-y))
48 # Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
49 suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
50 # List composite targets that are constructed by combining other targets
51 multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
52 # List primitive targets that are compiled from source files
53 real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
55 # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
56 multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
57 multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
58 multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
60 # Replace multi-part objects by their individual parts,
61 # including built-in.a from subdirectories
62 real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
63 real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
65 always-y += $(always-m)
67 # hostprogs-always-y += foo
68 # ... is a shorthand for
71 hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
72 always-y += $(hostprogs-always-y) $(hostprogs-always-m)
74 # userprogs-always-y is likewise.
75 userprogs += $(userprogs-always-y) $(userprogs-always-m)
76 always-y += $(userprogs-always-y) $(userprogs-always-m)
79 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
80 dtb-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
82 # Composite DTB (i.e. DTB constructed by overlay)
83 multi-dtb-y := $(call multi-search, $(dtb-y), .dtb, -dtbs)
84 # Primitive DTB compiled from *.dts
85 real-dtb-y := $(call real-search, $(dtb-y), .dtb, -dtbs)
86 # Base DTB that overlay is applied onto (each first word of $(*-dtbs) expansion)
87 base-dtb-y := $(foreach m, $(multi-dtb-y), $(firstword $(call suffix-search, $m, .dtb, -dtbs)))
94 extra-y := $(addprefix $(obj)/,$(extra-y))
95 always-y := $(addprefix $(obj)/,$(always-y))
96 targets := $(addprefix $(obj)/,$(targets))
97 obj-m := $(addprefix $(obj)/,$(obj-m))
98 lib-y := $(addprefix $(obj)/,$(lib-y))
99 real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
100 real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
101 multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m))
102 multi-dtb-y := $(addprefix $(obj)/, $(multi-dtb-y))
103 real-dtb-y := $(addprefix $(obj)/, $(real-dtb-y))
104 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
107 # Finds the multi-part object the current object will be linked into.
108 # If the object belongs to two or more multi-part objects, list them all.
109 modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
110 $(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))
112 __modname = $(or $(modname-multi),$(basetarget))
114 modname = $(subst $(space),:,$(__modname))
115 modfile = $(addprefix $(obj)/,$(__modname))
117 # target with $(obj)/ and its suffix stripped
118 target-stem = $(basename $(patsubst $(obj)/%,%,$@))
120 # These flags are needed for modversions and compiling, so we define them here
121 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
122 # end up in (or would, if it gets compiled in)
123 name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
124 name-fix = $(call stringify,$(call name-fix-token,$1))
125 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
126 modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
127 -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
128 modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
130 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
131 $(filter-out $(ccflags-remove-y), \
132 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
133 $(CFLAGS_$(target-stem).o))
134 _rust_flags = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \
135 $(filter-out $(rustflags-remove-y), \
136 $(KBUILD_RUSTFLAGS) $(rustflags-y)) \
137 $(RUSTFLAGS_$(target-stem).o))
138 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
139 $(filter-out $(asflags-remove-y), \
140 $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
141 $(AFLAGS_$(target-stem).o))
142 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
145 # Enable gcov profiling flags for a file, directory or for all files depending
146 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
149 ifeq ($(CONFIG_GCOV_KERNEL),y)
150 _c_flags += $(if $(patsubst n%,, \
151 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
156 # Enable address sanitizer flags for kernel except some files or directories
157 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
159 ifeq ($(CONFIG_KASAN),y)
160 ifneq ($(CONFIG_KASAN_HW_TAGS),y)
161 _c_flags += $(if $(patsubst n%,, \
162 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
163 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
167 ifeq ($(CONFIG_KMSAN),y)
168 _c_flags += $(if $(patsubst n%,, \
169 $(KMSAN_SANITIZE_$(basetarget).o)$(KMSAN_SANITIZE)y), \
171 _c_flags += $(if $(patsubst n%,, \
172 $(KMSAN_ENABLE_CHECKS_$(basetarget).o)$(KMSAN_ENABLE_CHECKS)y), \
173 , -mllvm -msan-disable-checks=1)
176 ifeq ($(CONFIG_UBSAN),y)
177 _c_flags += $(if $(patsubst n%,, \
178 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
182 ifeq ($(CONFIG_KCOV),y)
183 _c_flags += $(if $(patsubst n%,, \
184 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
189 # Enable KCSAN flags except some files or directories we don't want to check
190 # (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
192 ifeq ($(CONFIG_KCSAN),y)
193 _c_flags += $(if $(patsubst n%,, \
194 $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \
196 # Some uninstrumented files provide implied barriers required to avoid false
197 # positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.
198 _c_flags += $(if $(patsubst n%,, \
199 $(KCSAN_INSTRUMENT_BARRIERS_$(basetarget).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
200 -D__KCSAN_INSTRUMENT_BARRIERS__)
203 # $(srctree)/$(src) for including checkin headers from generated source files
204 # $(objtree)/$(obj) for including generated headers from checkin source files
205 ifeq ($(KBUILD_EXTMOD),)
206 ifdef building_out_of_srctree
207 _c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
208 _a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
209 _cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
213 part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
214 quiet_modtag = $(if $(part-of-module),[M], )
217 $(if $(part-of-module), \
218 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
219 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
221 modkern_rustflags = \
222 $(if $(part-of-module), \
223 $(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \
224 $(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))
226 modkern_aflags = $(if $(part-of-module), \
227 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
228 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
230 c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
231 -include $(srctree)/include/linux/compiler_types.h \
232 $(_c_flags) $(modkern_cflags) \
233 $(basename_flags) $(modname_flags)
235 rust_flags = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
237 a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
238 $(_a_flags) $(modkern_aflags)
240 cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
243 ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
245 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
247 dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \
248 $(addprefix -I,$(DTC_INCLUDE)) \
253 objtool := $(objtree)/tools/objtool/objtool
255 objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label
256 objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr
257 objtool-args-$(CONFIG_CALL_DEPTH_TRACKING) += --hacks=skylake
258 objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt
259 objtool-args-$(CONFIG_FINEIBT) += --cfi
260 objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount
261 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
262 objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT) += --mnop
264 objtool-args-$(CONFIG_UNWINDER_ORC) += --orc
265 objtool-args-$(CONFIG_RETPOLINE) += --retpoline
266 objtool-args-$(CONFIG_RETHUNK) += --rethunk
267 objtool-args-$(CONFIG_SLS) += --sls
268 objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval
269 objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call
270 objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess
271 objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable
272 objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES)
274 objtool-args = $(objtool-args-y) \
275 $(if $(delay-objtool), --link) \
276 $(if $(part-of-module), --module)
278 delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
280 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
281 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
283 endif # CONFIG_OBJTOOL
285 # Useful for describing the dependency of composite objects
287 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
291 $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
295 # ===========================================================================
296 # 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
297 # the copy would be read-only as well, leading to an error when executing the
298 # rule next time. Use 'cat' instead in order to generate a writable file.
299 quiet_cmd_copy = COPY $@
300 cmd_copy = cat $< > $@
302 $(obj)/%: $(src)/%_shipped
305 # Commands useful for building a boot image
306 # ===========================================================================
310 # target: source(s) FORCE
311 # $(if_changed,ld/objcopy/gzip)
313 # and add target to 'targets' so that we know we have to
314 # read in the saved command line
317 # ---------------------------------------------------------------------------
320 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
323 # ---------------------------------------------------------------------------
326 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
329 # ---------------------------------------------------------------------------
331 quiet_cmd_objcopy = OBJCOPY $@
332 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
335 # ---------------------------------------------------------------------------
337 quiet_cmd_gzip = GZIP $@
338 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
341 # ---------------------------------------------------------------------------
342 DTC ?= $(objtree)/scripts/dtc/dtc
343 DTC_FLAGS += -Wno-interrupt_provider \
344 -Wno-unique_unit_address
346 # Disable noisy checks by default
347 ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
348 DTC_FLAGS += -Wno-unit_address_vs_reg \
349 -Wno-avoid_unnecessary_addr_size \
351 -Wno-graph_child_address \
355 -Wunique_unit_address_if_enabled
358 ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
359 DTC_FLAGS += -Wnode_name_chars_strict \
360 -Wproperty_name_chars_strict \
361 -Winterrupt_provider \
362 -Wunique_unit_address
365 DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
367 # Set -@ if the target is a base DTB that overlay is applied onto
368 DTC_FLAGS += $(if $(filter $(patsubst $(obj)/%,%,$@), $(base-dtb-y)), -@)
370 # Generate an assembly file to wrap the output of the device tree compiler
371 quiet_cmd_dt_S_dtb= DTBS $@
374 echo '\#include <asm-generic/vmlinux.lds.h>'; \
375 echo '.section .dtb.init.rodata,"a"'; \
376 echo '.balign STRUCT_ALIGNMENT'; \
377 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
378 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
379 echo '.incbin "$<" '; \
380 echo '__dtb_$(subst -,_,$(*F))_end:'; \
381 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
382 echo '.balign STRUCT_ALIGNMENT'; \
385 $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
386 $(call if_changed,dt_S_dtb)
388 # Generate an assembly file to wrap the output of the device tree compiler
389 quiet_cmd_dt_S_dtbo= DTBOS $@
392 echo '\#include <asm-generic/vmlinux.lds.h>'; \
393 echo '.section .dtb.init.rodata,"a"'; \
394 echo '.balign STRUCT_ALIGNMENT'; \
395 echo '.global __dtbo_$(subst -,_,$(*F))_begin'; \
396 echo '__dtbo_$(subst -,_,$(*F))_begin:'; \
397 echo '.incbin "$<" '; \
398 echo '__dtbo_$(subst -,_,$(*F))_end:'; \
399 echo '.global __dtbo_$(subst -,_,$(*F))_end'; \
400 echo '.balign STRUCT_ALIGNMENT'; \
403 $(obj)/%.dtbo.S: $(obj)/%.dtbo FORCE
404 $(call if_changed,dt_S_dtbo)
406 quiet_cmd_dtc = DTC $@
407 cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
409 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
410 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
411 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
413 quiet_cmd_fdtoverlay = DTOVL $@
414 cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
416 $(multi-dtb-y): FORCE
417 $(call if_changed,fdtoverlay)
418 $(call multi_depend, $(multi-dtb-y), .dtb, -dtbs)
420 ifneq ($(CHECK_DTBS)$(CHECK_DT_BINDING),)
421 DT_CHECKER ?= dt-validate
422 DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m)
423 DT_BINDING_DIR := Documentation/devicetree/bindings
424 DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
426 quiet_cmd_dtb = DTC_CHK $@
427 cmd_dtb = $(cmd_dtc) ; $(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true
429 quiet_cmd_dtb = $(quiet_cmd_dtc)
433 $(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
434 $(call if_changed_dep,dtb)
436 $(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE
437 $(call if_changed_dep,dtc)
439 $(obj)/%.dtbo: $(src)/%.dtso $(DTC) FORCE
440 $(call if_changed_dep,dtc)
442 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
445 # ---------------------------------------------------------------------------
447 # Bzip2 and LZMA do not include size in file... so we have to fake that;
448 # append the size as a 32-bit littleendian number as gzip does.
449 size_append = printf $(shell \
451 for F in $(real-prereqs); do \
452 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
453 dec_size=$$(expr $$dec_size + $$fsize); \
455 printf "%08x\n" $$dec_size | \
456 sed 's/\(..\)/\1 /g' | { \
457 read ch0 ch1 ch2 ch3; \
458 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
459 printf '%s%03o' '\\' $$((0x$$ch)); \
464 quiet_cmd_file_size = GEN $@
465 cmd_file_size = $(size_append) > $@
467 quiet_cmd_bzip2 = BZIP2 $@
468 cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
470 quiet_cmd_bzip2_with_size = BZIP2 $@
471 cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
474 # ---------------------------------------------------------------------------
476 quiet_cmd_lzma = LZMA $@
477 cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
479 quiet_cmd_lzma_with_size = LZMA $@
480 cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
482 quiet_cmd_lzo = LZO $@
483 cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
485 quiet_cmd_lzo_with_size = LZO $@
486 cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
488 quiet_cmd_lz4 = LZ4 $@
489 cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@
491 quiet_cmd_lz4_with_size = LZ4 $@
492 cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
493 $(size_append); } > $@
496 # ---------------------------------------------------------------------------
498 MKIMAGE := $(srctree)/scripts/mkuboot.sh
500 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
501 # the number of overrides in arch makefiles
502 UIMAGE_ARCH ?= $(SRCARCH)
503 UIMAGE_COMPRESSION ?= $(or $(2),none)
505 UIMAGE_TYPE ?= kernel
506 UIMAGE_LOADADDR ?= arch_must_set_this
507 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
508 UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
510 quiet_cmd_uimage = UIMAGE $@
511 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
512 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
514 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
515 -n $(UIMAGE_NAME) -d $< $@
518 # ---------------------------------------------------------------------------
519 # Use xzkern to compress the kernel image and xzmisc to compress other things.
521 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
522 # of the kernel decompressor. A BCJ filter is used if it is available for
523 # the target architecture. xzkern also appends uncompressed size of the data
524 # using size_append. The .xz format has the size information available at
525 # the end of the file too, but it's in more complex format and it's good to
526 # avoid changing the part of the boot code that reads the uncompressed size.
527 # Note that the bytes added by size_append will make the xz tool think that
528 # the file is corrupt. This is expected.
530 # xzmisc doesn't use size_append, so it can be used to create normal .xz
531 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
532 # big dictionary would increase the memory usage too much in the multi-call
533 # decompression mode. A BCJ filter isn't used either.
534 quiet_cmd_xzkern = XZKERN $@
535 cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
537 quiet_cmd_xzkern_with_size = XZKERN $@
538 cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
539 $(size_append); } > $@
541 quiet_cmd_xzmisc = XZMISC $@
542 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
545 # ---------------------------------------------------------------------------
546 # Appends the uncompressed size of the data using size_append. The .zst
547 # format has the size information available at the beginning of the file too,
548 # but it's in a more complex format and it's good to avoid changing the part
549 # of the boot code that reads the uncompressed size.
551 # Note that the bytes added by size_append will make the zstd tool think that
552 # the file is corrupt. This is expected.
554 # zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
555 # 128 MB. zstd22 is used for kernel compression because it is decompressed in a
556 # single pass, so zstd doesn't need to allocate a window buffer. When streaming
557 # decompression is used, like initramfs decompression, zstd22 should likely not
558 # be used because it would require zstd to allocate a 128 MB buffer.
560 quiet_cmd_zstd = ZSTD $@
561 cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
563 quiet_cmd_zstd22 = ZSTD22 $@
564 cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
566 quiet_cmd_zstd22_with_size = ZSTD22 $@
567 cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
570 # ---------------------------------------------------------------------------
572 # Default sed regexp - multiline due to syntax constraints
574 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
575 # the .ascii directive whereas GCC keeps the <space> as-is.
577 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
578 /^->/{s:->#\(.*\):/* \1 */:; \
579 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
583 # Use filechk to avoid rebuilds when a header changes, but the resulting file
585 define filechk_offsets
589 echo " * DO NOT MODIFY."; \
591 echo " * This file was generated by Kbuild"; \
594 sed -ne $(sed-offsets) < $<; \