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))
49 dtb-y += $(addsuffix /dtbs-list, $(subdir-ym))
53 # Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
54 suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
55 # List composite targets that are constructed by combining other targets
56 multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
57 # List primitive targets that are compiled from source files
58 real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
60 # If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
61 multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
62 multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
63 multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
65 # Replace multi-part objects by their individual parts,
66 # including built-in.a from subdirectories
67 real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
68 real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
70 always-y += $(always-m)
72 # hostprogs-always-y += foo
73 # ... is a shorthand for
76 hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
77 always-y += $(hostprogs-always-y) $(hostprogs-always-m)
79 # userprogs-always-y is likewise.
80 userprogs += $(userprogs-always-y) $(userprogs-always-m)
81 always-y += $(userprogs-always-y) $(userprogs-always-m)
84 # If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
85 dtb-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
87 # Composite DTB (i.e. DTB constructed by overlay)
88 multi-dtb-y := $(call multi-search, $(dtb-y), .dtb, -dtbs)
89 # Primitive DTB compiled from *.dts
90 real-dtb-y := $(call real-search, $(dtb-y), .dtb, -dtbs)
91 # Base DTB that overlay is applied onto
92 base-dtb-y := $(filter %.dtb, $(call real-search, $(multi-dtb-y), .dtb, -dtbs))
99 extra-y := $(addprefix $(obj)/,$(extra-y))
100 always-y := $(addprefix $(obj)/,$(always-y))
101 targets := $(addprefix $(obj)/,$(targets))
102 obj-m := $(addprefix $(obj)/,$(obj-m))
103 lib-y := $(addprefix $(obj)/,$(lib-y))
104 real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
105 real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
106 multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m))
107 dtb-y := $(addprefix $(obj)/, $(dtb-y))
108 multi-dtb-y := $(addprefix $(obj)/, $(multi-dtb-y))
109 real-dtb-y := $(addprefix $(obj)/, $(real-dtb-y))
110 subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
113 # Finds the multi-part object the current object will be linked into.
114 # If the object belongs to two or more multi-part objects, list them all.
115 modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
116 $(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))
118 __modname = $(or $(modname-multi),$(basetarget))
120 modname = $(subst $(space),:,$(__modname))
121 modfile = $(addprefix $(obj)/,$(__modname))
123 # target with $(obj)/ and its suffix stripped
124 target-stem = $(basename $(patsubst $(obj)/%,%,$@))
126 # These flags are needed for modversions and compiling, so we define them here
127 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
128 # end up in (or would, if it gets compiled in)
129 name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
130 name-fix = $(call stringify,$(call name-fix-token,$1))
131 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
132 modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
133 -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
134 modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
136 _c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
137 $(filter-out $(ccflags-remove-y), \
138 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
139 $(CFLAGS_$(target-stem).o))
140 _rust_flags = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \
141 $(filter-out $(rustflags-remove-y), \
142 $(KBUILD_RUSTFLAGS) $(rustflags-y)) \
143 $(RUSTFLAGS_$(target-stem).o))
144 _a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
145 $(filter-out $(asflags-remove-y), \
146 $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
147 $(AFLAGS_$(target-stem).o))
148 _cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
151 # Enable gcov profiling flags for a file, directory or for all files depending
152 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
155 ifeq ($(CONFIG_GCOV_KERNEL),y)
156 _c_flags += $(if $(patsubst n%,, \
157 $(GCOV_PROFILE_$(target-stem).o)$(GCOV_PROFILE)$(if $(is-kernel-object),$(CONFIG_GCOV_PROFILE_ALL))), \
162 # Enable address sanitizer flags for kernel except some files or directories
163 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
165 ifeq ($(CONFIG_KASAN),y)
166 ifneq ($(CONFIG_KASAN_HW_TAGS),y)
167 _c_flags += $(if $(patsubst n%,, \
168 $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \
169 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
173 ifeq ($(CONFIG_KMSAN),y)
174 _c_flags += $(if $(patsubst n%,, \
175 $(KMSAN_SANITIZE_$(target-stem).o)$(KMSAN_SANITIZE)$(is-kernel-object)), \
177 _c_flags += $(if $(patsubst n%,, \
178 $(KMSAN_ENABLE_CHECKS_$(target-stem).o)$(KMSAN_ENABLE_CHECKS)$(is-kernel-object)), \
179 , -mllvm -msan-disable-checks=1)
182 ifeq ($(CONFIG_UBSAN),y)
183 _c_flags += $(if $(patsubst n%,, \
184 $(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SANITIZE)$(is-kernel-object)), \
186 _c_flags += $(if $(patsubst n%,, \
187 $(UBSAN_SIGNED_WRAP_$(target-stem).o)$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SIGNED_WRAP)$(UBSAN_SANITIZE)$(is-kernel-object)), \
188 $(CFLAGS_UBSAN_SIGNED_WRAP))
191 ifeq ($(CONFIG_KCOV),y)
192 _c_flags += $(if $(patsubst n%,, \
193 $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \
198 # Enable KCSAN flags except some files or directories we don't want to check
199 # (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
201 ifeq ($(CONFIG_KCSAN),y)
202 _c_flags += $(if $(patsubst n%,, \
203 $(KCSAN_SANITIZE_$(target-stem).o)$(KCSAN_SANITIZE)$(is-kernel-object)), \
205 # Some uninstrumented files provide implied barriers required to avoid false
206 # positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.
207 _c_flags += $(if $(patsubst n%,, \
208 $(KCSAN_INSTRUMENT_BARRIERS_$(target-stem).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
209 -D__KCSAN_INSTRUMENT_BARRIERS__)
212 # $(src) for including checkin headers from generated source files
213 # $(obj) for including generated headers from checkin source files
214 ifeq ($(KBUILD_EXTMOD),)
215 ifdef building_out_of_srctree
216 _c_flags += $(addprefix -I, $(src) $(obj))
217 _a_flags += $(addprefix -I, $(src) $(obj))
218 _cpp_flags += $(addprefix -I, $(src) $(obj))
222 # If $(is-kernel-object) is 'y', this object will be linked to vmlinux or modules
223 is-kernel-object = $(or $(part-of-builtin),$(part-of-module))
225 part-of-builtin = $(if $(filter $(basename $@).o, $(real-obj-y) $(lib-y)),y)
226 part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
227 quiet_modtag = $(if $(part-of-module),[M], )
230 $(if $(part-of-module), \
231 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
232 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
234 modkern_rustflags = \
235 $(if $(part-of-module), \
236 $(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \
237 $(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))
239 modkern_aflags = $(if $(part-of-module), \
240 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
241 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
243 c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
244 -include $(srctree)/include/linux/compiler_types.h \
245 $(_c_flags) $(modkern_cflags) \
246 $(basename_flags) $(modname_flags)
248 rust_flags = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
250 a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
251 $(_a_flags) $(modkern_aflags)
253 cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
256 ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
258 DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
260 dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \
261 $(addprefix -I,$(DTC_INCLUDE)) \
266 objtool := $(objtree)/tools/objtool/objtool
268 objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label
269 objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr
270 objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake
271 objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt
272 objtool-args-$(CONFIG_FINEIBT) += --cfi
273 objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount
274 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
275 objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT) += --mnop
277 objtool-args-$(CONFIG_UNWINDER_ORC) += --orc
278 objtool-args-$(CONFIG_MITIGATION_RETPOLINE) += --retpoline
279 objtool-args-$(CONFIG_MITIGATION_RETHUNK) += --rethunk
280 objtool-args-$(CONFIG_MITIGATION_SLS) += --sls
281 objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval
282 objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call
283 objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess
284 objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable
285 objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES)
287 objtool-args = $(objtool-args-y) \
288 $(if $(delay-objtool), --link) \
289 $(if $(part-of-module), --module)
291 delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
293 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
294 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
296 endif # CONFIG_OBJTOOL
298 # Useful for describing the dependency of composite objects
300 # $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
304 $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
308 # ===========================================================================
309 # 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
310 # the copy would be read-only as well, leading to an error when executing the
311 # rule next time. Use 'cat' instead in order to generate a writable file.
312 quiet_cmd_copy = COPY $@
313 cmd_copy = cat $< > $@
315 $(obj)/%: $(src)/%_shipped
318 # Commands useful for building a boot image
319 # ===========================================================================
323 # target: source(s) FORCE
324 # $(if_changed,ld/objcopy/gzip)
326 # and add target to 'targets' so that we know we have to
327 # read in the saved command line
330 # ---------------------------------------------------------------------------
333 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
336 # ---------------------------------------------------------------------------
339 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
342 # ---------------------------------------------------------------------------
344 quiet_cmd_objcopy = OBJCOPY $@
345 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
348 # ---------------------------------------------------------------------------
350 quiet_cmd_gzip = GZIP $@
351 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
354 # ---------------------------------------------------------------------------
355 DTC ?= $(objtree)/scripts/dtc/dtc
357 -Wno-unique_unit_address
359 # Disable noisy checks by default
360 ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
361 DTC_FLAGS += -Wno-unit_address_vs_reg \
362 -Wno-avoid_unnecessary_addr_size \
364 -Wno-graph_child_address \
368 -Wunique_unit_address_if_enabled
371 ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
372 DTC_FLAGS += -Wnode_name_chars_strict \
373 -Wproperty_name_chars_strict \
374 -Wunique_unit_address
377 DTC_FLAGS += $(DTC_FLAGS_$(target-stem))
379 # Set -@ if the target is a base DTB that overlay is applied onto
380 DTC_FLAGS += $(if $(filter $(patsubst $(obj)/%,%,$@), $(base-dtb-y)), -@)
382 # Generate an assembly file to wrap the output of the device tree compiler
383 quiet_cmd_wrap_S_dtb = WRAP $@
385 symbase=__$(patsubst .%,%,$(suffix $<))_$(subst -,_,$(notdir $*)); \
386 echo '\#include <asm-generic/vmlinux.lds.h>'; \
387 echo '.section .dtb.init.rodata,"a"'; \
388 echo '.balign STRUCT_ALIGNMENT'; \
389 echo ".global $${symbase}_begin"; \
390 echo "$${symbase}_begin:"; \
391 echo '.incbin "$<" '; \
392 echo ".global $${symbase}_end"; \
393 echo "$${symbase}_end:"; \
394 echo '.balign STRUCT_ALIGNMENT'; \
397 $(obj)/%.dtb.S: $(obj)/%.dtb FORCE
398 $(call if_changed,wrap_S_dtb)
400 $(obj)/%.dtbo.S: $(obj)/%.dtbo FORCE
401 $(call if_changed,wrap_S_dtb)
403 quiet_cmd_dtc = DTC $@
404 cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
406 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
407 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
408 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
410 quiet_cmd_fdtoverlay = DTOVL $@
411 cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
413 $(multi-dtb-y): FORCE
414 $(call if_changed,fdtoverlay)
415 $(call multi_depend, $(multi-dtb-y), .dtb, -dtbs)
417 ifneq ($(CHECK_DTBS),)
418 DT_CHECKER ?= dt-validate
419 DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m)
420 DT_BINDING_DIR := Documentation/devicetree/bindings
421 DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
423 quiet_cmd_dtb = DTC_CHK $@
424 cmd_dtb = $(cmd_dtc) ; $(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true
426 quiet_cmd_dtb = $(quiet_cmd_dtc)
430 $(obj)/%.dtb: $(obj)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
431 $(call if_changed_dep,dtb)
433 $(obj)/%.dtbo: $(src)/%.dtso $(DTC) FORCE
434 $(call if_changed_dep,dtc)
436 dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
439 # ---------------------------------------------------------------------------
441 # Bzip2 and LZMA do not include size in file... so we have to fake that;
442 # append the size as a 32-bit littleendian number as gzip does.
443 size_append = printf $(shell \
445 for F in $(real-prereqs); do \
446 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
447 dec_size=$$(expr $$dec_size + $$fsize); \
449 printf "%08x\n" $$dec_size | \
450 sed 's/\(..\)/\1 /g' | { \
451 read ch0 ch1 ch2 ch3; \
452 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
453 printf '%s%03o' '\\' $$((0x$$ch)); \
458 quiet_cmd_file_size = GEN $@
459 cmd_file_size = $(size_append) > $@
461 quiet_cmd_bzip2 = BZIP2 $@
462 cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
464 quiet_cmd_bzip2_with_size = BZIP2 $@
465 cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
468 # ---------------------------------------------------------------------------
470 quiet_cmd_lzma = LZMA $@
471 cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
473 quiet_cmd_lzma_with_size = LZMA $@
474 cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
476 quiet_cmd_lzo = LZO $@
477 cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
479 quiet_cmd_lzo_with_size = LZO $@
480 cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
482 quiet_cmd_lz4 = LZ4 $@
483 cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@
485 quiet_cmd_lz4_with_size = LZ4 $@
486 cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
487 $(size_append); } > $@
490 # ---------------------------------------------------------------------------
492 MKIMAGE := $(srctree)/scripts/mkuboot.sh
494 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
495 # the number of overrides in arch makefiles
496 UIMAGE_ARCH ?= $(SRCARCH)
497 UIMAGE_COMPRESSION ?= $(or $(2),none)
499 UIMAGE_TYPE ?= kernel
500 UIMAGE_LOADADDR ?= arch_must_set_this
501 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
502 UIMAGE_NAME ?= Linux-$(KERNELRELEASE)
504 quiet_cmd_uimage = UIMAGE $@
505 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
506 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
508 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
509 -n '$(UIMAGE_NAME)' -d $< $@
511 # Flat Image Tree (FIT)
512 # This allows for packaging of a kernel and all devicetrees files, using
514 # ---------------------------------------------------------------------------
516 MAKE_FIT := $(srctree)/scripts/make_fit.py
518 # Use this to override the compression algorithm
519 FIT_COMPRESSION ?= gzip
521 quiet_cmd_fit = FIT $@
522 cmd_fit = $(MAKE_FIT) -o $@ --arch $(UIMAGE_ARCH) --os linux \
523 --name '$(UIMAGE_NAME)' \
524 $(if $(findstring 1,$(KBUILD_VERBOSE)),-v) \
525 --compress $(FIT_COMPRESSION) -k $< @$(word 2,$^)
528 # ---------------------------------------------------------------------------
529 # Use xzkern to compress the kernel image and xzmisc to compress other things.
531 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
532 # of the kernel decompressor. A BCJ filter is used if it is available for
533 # the target architecture. xzkern also appends uncompressed size of the data
534 # using size_append. The .xz format has the size information available at
535 # the end of the file too, but it's in more complex format and it's good to
536 # avoid changing the part of the boot code that reads the uncompressed size.
537 # Note that the bytes added by size_append will make the xz tool think that
538 # the file is corrupt. This is expected.
540 # xzmisc doesn't use size_append, so it can be used to create normal .xz
541 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
542 # big dictionary would increase the memory usage too much in the multi-call
543 # decompression mode. A BCJ filter isn't used either.
544 quiet_cmd_xzkern = XZKERN $@
545 cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
547 quiet_cmd_xzkern_with_size = XZKERN $@
548 cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
549 $(size_append); } > $@
551 quiet_cmd_xzmisc = XZMISC $@
552 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
555 # ---------------------------------------------------------------------------
556 # Appends the uncompressed size of the data using size_append. The .zst
557 # format has the size information available at the beginning of the file too,
558 # but it's in a more complex format and it's good to avoid changing the part
559 # of the boot code that reads the uncompressed size.
561 # Note that the bytes added by size_append will make the zstd tool think that
562 # the file is corrupt. This is expected.
564 # zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
565 # 128 MB. zstd22 is used for kernel compression because it is decompressed in a
566 # single pass, so zstd doesn't need to allocate a window buffer. When streaming
567 # decompression is used, like initramfs decompression, zstd22 should likely not
568 # be used because it would require zstd to allocate a 128 MB buffer.
570 quiet_cmd_zstd = ZSTD $@
571 cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
573 quiet_cmd_zstd22 = ZSTD22 $@
574 cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
576 quiet_cmd_zstd22_with_size = ZSTD22 $@
577 cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
580 # ---------------------------------------------------------------------------
582 # Default sed regexp - multiline due to syntax constraints
584 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
585 # the .ascii directive whereas GCC keeps the <space> as-is.
587 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
588 /^->/{s:->#\(.*\):/* \1 */:; \
589 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
593 # Use filechk to avoid rebuilds when a header changes, but the resulting file
595 define filechk_offsets
599 echo " * DO NOT MODIFY."; \
601 echo " * This file was generated by Kbuild"; \
604 sed -ne $(sed-offsets) < $<; \