scripts/Makefile.lib

   1 # SPDX-License-Identifier: GPL-2.0
   2
   3 # Finds the multi-part object the current object will be linked into.
   4 # If the object belongs to two or more multi-part objects, list them all.
   5 modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
   6                 $(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))
   7
   8 __modname = $(or $(modname-multi),$(basetarget))
   9
  10 modname = $(subst $(space),:,$(__modname))
  11 modfile = $(addprefix $(obj)/,$(__modname))
  12
  13 # target with $(obj)/ and its suffix stripped
  14 target-stem = $(basename $(patsubst $(obj)/%,%,$@))
  15
  16 # These flags are needed for modversions and compiling, so we define them here
  17 # $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
  18 # end up in (or would, if it gets compiled in)
  19 name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
  20 name-fix = $(call stringify,$(call name-fix-token,$1))
  21 basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
  22 modname_flags  = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
  23                  -D__KBUILD_MODNAME=$(call name-fix-token,$(modname))
  24 modfile_flags  = -DKBUILD_MODFILE=$(call stringify,$(modfile))
  25
  26 _c_flags       = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
  27                      $(filter-out $(ccflags-remove-y), \
  28                          $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
  29                      $(CFLAGS_$(target-stem).o))
  30 _rust_flags    = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \
  31                      $(filter-out $(rustflags-remove-y), \
  32                          $(KBUILD_RUSTFLAGS) $(rustflags-y)) \
  33                      $(RUSTFLAGS_$(target-stem).o))
  34 _a_flags       = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
  35                      $(filter-out $(asflags-remove-y), \
  36                          $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
  37                      $(AFLAGS_$(target-stem).o))
  38 _cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
  39
  40 #
  41 # Enable gcov profiling flags for a file, directory or for all files depending
  42 # on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
  43 # (in this order)
  44 #
  45 ifeq ($(CONFIG_GCOV_KERNEL),y)
  46 _c_flags += $(if $(patsubst n%,, \
  47                 $(GCOV_PROFILE_$(target-stem).o)$(GCOV_PROFILE)$(if $(is-kernel-object),$(CONFIG_GCOV_PROFILE_ALL))), \
  48                 $(CFLAGS_GCOV))
  49 endif
  50
  51 #
  52 # Enable address sanitizer flags for kernel except some files or directories
  53 # we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
  54 #
  55 ifeq ($(CONFIG_KASAN),y)
  56 ifneq ($(CONFIG_KASAN_HW_TAGS),y)
  57 _c_flags += $(if $(patsubst n%,, \
  58                 $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \
  59                 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
  60 _rust_flags += $(if $(patsubst n%,, \
  61                 $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \
  62                 $(RUSTFLAGS_KASAN))
  63 endif
  64 endif
  65
  66 ifeq ($(CONFIG_KMSAN),y)
  67 _c_flags += $(if $(patsubst n%,, \
  68                 $(KMSAN_SANITIZE_$(target-stem).o)$(KMSAN_SANITIZE)$(is-kernel-object)), \
  69                 $(CFLAGS_KMSAN))
  70 _c_flags += $(if $(patsubst n%,, \
  71                 $(KMSAN_ENABLE_CHECKS_$(target-stem).o)$(KMSAN_ENABLE_CHECKS)$(is-kernel-object)), \
  72                 , -mllvm -msan-disable-checks=1)
  73 endif
  74
  75 ifeq ($(CONFIG_UBSAN),y)
  76 _c_flags += $(if $(patsubst n%,, \
  77                 $(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SANITIZE)$(is-kernel-object)), \
  78                 $(CFLAGS_UBSAN))
  79 _c_flags += $(if $(patsubst n%,, \
  80                 $(UBSAN_INTEGER_WRAP_$(target-stem).o)$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_INTEGER_WRAP)$(UBSAN_SANITIZE)$(is-kernel-object)), \
  81                 $(CFLAGS_UBSAN_INTEGER_WRAP))
  82 endif
  83
  84 ifeq ($(CONFIG_KCOV),y)
  85 _c_flags += $(if $(patsubst n%,, \
  86         $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \
  87         $(CFLAGS_KCOV))
  88 _rust_flags += $(if $(patsubst n%,, \
  89         $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \
  90         $(RUSTFLAGS_KCOV))
  91 endif
  92
  93 #
  94 # Enable KCSAN flags except some files or directories we don't want to check
  95 # (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
  96 #
  97 ifeq ($(CONFIG_KCSAN),y)
  98 _c_flags += $(if $(patsubst n%,, \
  99         $(KCSAN_SANITIZE_$(target-stem).o)$(KCSAN_SANITIZE)$(is-kernel-object)), \
 100         $(CFLAGS_KCSAN))
 101 # Some uninstrumented files provide implied barriers required to avoid false
 102 # positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.
 103 _c_flags += $(if $(patsubst n%,, \
 104         $(KCSAN_INSTRUMENT_BARRIERS_$(target-stem).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
 105         -D__KCSAN_INSTRUMENT_BARRIERS__)
 106 endif
 107
 108 #
 109 # Enable context analysis flags only where explicitly opted in.
 110 # (depends on variables CONTEXT_ANALYSIS_obj.o, CONTEXT_ANALYSIS)
 111 #
 112 ifeq ($(CONFIG_WARN_CONTEXT_ANALYSIS),y)
 113 _c_flags += $(if $(patsubst n%,, \
 114                 $(CONTEXT_ANALYSIS_$(target-stem).o)$(CONTEXT_ANALYSIS)$(if $(is-kernel-object),$(CONFIG_WARN_CONTEXT_ANALYSIS_ALL))), \
 115                 $(CFLAGS_CONTEXT_ANALYSIS))
 116 endif
 117
 118 #
 119 # Enable AutoFDO build flags except some files or directories we don't want to
 120 # enable (depends on variables AUTOFDO_PROFILE_obj.o and AUTOFDO_PROFILE).
 121 #
 122 ifeq ($(CONFIG_AUTOFDO_CLANG),y)
 123 _c_flags += $(if $(patsubst n%,, \
 124         $(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(is-kernel-object)), \
 125         $(CFLAGS_AUTOFDO_CLANG))
 126 endif
 127
 128 #
 129 # Enable Propeller build flags except some files or directories we don't want to
 130 # enable (depends on variables AUTOFDO_PROPELLER_obj.o and PROPELLER_PROFILE).
 131 #
 132 ifdef CONFIG_PROPELLER_CLANG
 133 _c_flags += $(if $(patsubst n%,, \
 134         $(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(PROPELLER_PROFILE))$(is-kernel-object), \
 135         $(CFLAGS_PROPELLER_CLANG))
 136 endif
 137
 138 # $(src) for including checkin headers from generated source files
 139 # $(obj) for including generated headers from checkin source files
 140 ifdef building_out_of_srctree
 141 _c_flags   += $(addprefix -I, $(src) $(obj))
 142 _a_flags   += $(addprefix -I, $(src) $(obj))
 143 _cpp_flags += $(addprefix -I, $(src) $(obj))
 144 endif
 145
 146 # If $(is-kernel-object) is 'y', this object will be linked to vmlinux or modules
 147 is-kernel-object = $(or $(part-of-builtin),$(part-of-module))
 148
 149 part-of-builtin = $(if $(filter $(basename $@).o, $(real-obj-y) $(lib-y)),y)
 150 part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
 151 quiet_modtag = $(if $(part-of-module),[M],   )
 152
 153 modkern_cflags =                                          \
 154         $(if $(part-of-module),                           \
 155                 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
 156                 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
 157
 158 modkern_rustflags =                                              \
 159         $(if $(part-of-module),                                   \
 160                 $(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \
 161                 $(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))
 162
 163 modkern_aflags = $(if $(part-of-module),                                \
 164                         $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE),       \
 165                         $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(modfile_flags))
 166
 167 c_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 168                  -include $(srctree)/include/linux/compiler_types.h       \
 169                  $(_c_flags) $(modkern_cflags)                           \
 170                  $(basename_flags) $(modname_flags)
 171
 172 rust_flags     = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
 173
 174 a_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 175                  $(_a_flags) $(modkern_aflags) $(modname_flags)
 176
 177 cpp_flags      = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 178                  $(_cpp_flags)
 179
 180 ld_flags       = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
 181
 182 ifdef CONFIG_OBJTOOL
 183
 184 objtool := $(objtree)/tools/objtool/objtool
 185
 186 objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK)             += --hacks=jump_label
 187 objtool-args-$(CONFIG_HAVE_NOINSTR_HACK)                += --hacks=noinstr
 188 objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING)   += --hacks=skylake
 189 objtool-args-$(CONFIG_X86_KERNEL_IBT)                   += --ibt
 190 objtool-args-$(CONFIG_FINEIBT)                          += --cfi
 191 objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL)        += --mcount
 192 ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL
 193 objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT)          += --mnop
 194 endif
 195 objtool-args-$(CONFIG_UNWINDER_ORC)                     += --orc
 196 objtool-args-$(CONFIG_MITIGATION_RETPOLINE)             += --retpoline
 197 objtool-args-$(CONFIG_MITIGATION_RETHUNK)               += --rethunk
 198 objtool-args-$(CONFIG_MITIGATION_SLS)                   += --sls
 199 objtool-args-$(CONFIG_STACK_VALIDATION)                 += --stackval
 200 objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE)          += --static-call
 201 objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION)          += --uaccess
 202 objtool-args-$(or $(CONFIG_GCOV_KERNEL),$(CONFIG_KCOV)) += --no-unreachable
 203 objtool-args-$(CONFIG_PREFIX_SYMBOLS)                   += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES)
 204 objtool-args-$(CONFIG_OBJTOOL_WERROR)                   += --werror
 205
 206 objtool-args = $(objtool-args-y)                                        \
 207         $(if $(delay-objtool), --link)                                  \
 208         $(if $(part-of-module), --module)
 209
 210 delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT),$(CONFIG_KLP_BUILD))
 211
 212 cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
 213 cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
 214
 215 objtool-enabled := y
 216
 217 endif # CONFIG_OBJTOOL
 218
 219 # Useful for describing the dependency of composite objects
 220 # Usage:
 221 #   $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
 222 define multi_depend
 223 $(foreach m, $1, \
 224         $(eval $m: \
 225         $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
 226 endef
 227
 228 # Remove ".." and "." from a path, without using "realpath"
 229 # Usage:
 230 #   $(call normalize_path,path/to/../file)
 231 define normalize_path
 232 $(strip $(eval elements :=) \
 233 $(foreach elem,$(subst /, ,$1), \
 234         $(if $(filter-out .,$(elem)), \
 235              $(if $(filter ..,$(elem)), \
 236                   $(eval elements := $(wordlist 2,$(words $(elements)),x $(elements))), \
 237                   $(eval elements := $(elements) $(elem))))) \
 238 $(subst $(space),/,$(elements)))
 239 endef
 240
 241 # Build commands
 242 # ===========================================================================
 243 # These are shared by some Makefile.* files.
 244
 245 ifdef CONFIG_LTO_CLANG
 246 # Run $(LD) here to convert LLVM IR to ELF in the following cases:
 247 #  - when this object needs objtool processing, as objtool cannot process LLVM IR
 248 #  - when this is a single-object module, as modpost cannot process LLVM IR
 249 cmd_ld_single = $(if $(objtool-enabled)$(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@)
 250 endif
 251
 252 quiet_cmd_cc_o_c = CC $(quiet_modtag)  $@
 253       cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \
 254                 $(cmd_ld_single) \
 255                 $(cmd_objtool)
 256
 257 define rule_cc_o_c
 258         $(call cmd_and_fixdep,cc_o_c)
 259         $(call cmd,checksrc)
 260         $(call cmd,checkdoc)
 261         $(call cmd,gen_objtooldep)
 262         $(call cmd,gen_symversions_c)
 263         $(call cmd,record_mcount)
 264         $(call cmd,warn_shared_object)
 265 endef
 266
 267 quiet_cmd_as_o_S = AS $(quiet_modtag)  $@
 268       cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool)
 269
 270 define rule_as_o_S
 271         $(call cmd_and_fixdep,as_o_S)
 272         $(call cmd,gen_objtooldep)
 273         $(call cmd,gen_symversions_S)
 274         $(call cmd,warn_shared_object)
 275 endef
 276
 277 # Copy a file
 278 # ===========================================================================
 279 # 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
 280 # the copy would be read-only as well, leading to an error when executing the
 281 # rule next time. Use 'cat' instead in order to generate a writable file.
 282 quiet_cmd_copy = COPY    $@
 283       cmd_copy = cat $< > $@
 284
 285 $(obj)/%: $(src)/%_shipped
 286         $(call cmd,copy)
 287
 288 # Touch a file
 289 # ===========================================================================
 290 quiet_cmd_touch = TOUCH   $(call normalize_path,$@)
 291       cmd_touch = touch $@
 292
 293 # Commands useful for building a boot image
 294 # ===========================================================================
 295 #
 296 #       Use as following:
 297 #
 298 #       target: source(s) FORCE
 299 #               $(if_changed,ld/objcopy/gzip)
 300 #
 301 #       and add target to 'targets' so that we know we have to
 302 #       read in the saved command line
 303
 304 # Linking
 305 # ---------------------------------------------------------------------------
 306
 307 quiet_cmd_ld = LD      $@
 308       cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
 309
 310 # Archive
 311 # ---------------------------------------------------------------------------
 312
 313 quiet_cmd_ar = AR      $@
 314       cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
 315
 316 # Objcopy
 317 # ---------------------------------------------------------------------------
 318
 319 quiet_cmd_objcopy = OBJCOPY $@
 320 cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
 321
 322 # Gzip
 323 # ---------------------------------------------------------------------------
 324
 325 quiet_cmd_gzip = GZIP    $@
 326       cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
 327
 328 # Bzip2
 329 # ---------------------------------------------------------------------------
 330
 331 # Bzip2 and LZMA do not include size in file... so we have to fake that;
 332 # append the size as a 32-bit littleendian number as gzip does.
 333 size_append = printf $(shell                                            \
 334 dec_size=0;                                                             \
 335 for F in $(real-prereqs); do                                    \
 336         fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F);  \
 337         dec_size=$$(expr $$dec_size + $$fsize);                         \
 338 done;                                                                   \
 339 printf "%08x\n" $$dec_size |                                            \
 340         sed 's/\(..\)/\1 /g' | {                                        \
 341                 read ch0 ch1 ch2 ch3;                                   \
 342                 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do                   \
 343                         printf '%s%03o' '\\' $$((0x$$ch));              \
 344                 done;                                                   \
 345         }                                                               \
 346 )
 347
 348 quiet_cmd_file_size = GEN     $@
 349       cmd_file_size = $(size_append) > $@
 350
 351 quiet_cmd_bzip2 = BZIP2   $@
 352       cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
 353
 354 quiet_cmd_bzip2_with_size = BZIP2   $@
 355       cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
 356
 357 # Lzma
 358 # ---------------------------------------------------------------------------
 359
 360 quiet_cmd_lzma = LZMA    $@
 361       cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
 362
 363 quiet_cmd_lzma_with_size = LZMA    $@
 364       cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
 365
 366 quiet_cmd_lzo = LZO     $@
 367       cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
 368
 369 quiet_cmd_lzo_with_size = LZO     $@
 370       cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
 371
 372 quiet_cmd_lz4 = LZ4     $@
 373       cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -9 - - > $@
 374
 375 quiet_cmd_lz4_with_size = LZ4     $@
 376       cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -9 - -; \
 377                   $(size_append); } > $@
 378
 379 # U-Boot mkimage
 380 # ---------------------------------------------------------------------------
 381
 382 MKIMAGE := $(srctree)/scripts/mkuboot.sh
 383
 384 # SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
 385 # the number of overrides in arch makefiles
 386 UIMAGE_ARCH ?= $(SRCARCH)
 387 UIMAGE_COMPRESSION ?= $(or $(2),none)
 388 UIMAGE_OPTS-y ?=
 389 UIMAGE_TYPE ?= kernel
 390 UIMAGE_LOADADDR ?= arch_must_set_this
 391 UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
 392 UIMAGE_NAME ?= Linux-$(KERNELRELEASE)
 393
 394 quiet_cmd_uimage = UIMAGE  $@
 395       cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
 396                         -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
 397                         -T $(UIMAGE_TYPE) \
 398                         -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
 399                         -n '$(UIMAGE_NAME)' -d $< $@
 400
 401 # Flat Image Tree (FIT)
 402 # This allows for packaging of a kernel and all devicetrees files, using
 403 # compression.
 404 # ---------------------------------------------------------------------------
 405
 406 MAKE_FIT := $(srctree)/scripts/make_fit.py
 407
 408 # Use this to override the compression algorithm
 409 FIT_COMPRESSION ?= gzip
 410
 411 quiet_cmd_fit = FIT     $@
 412       cmd_fit = $(MAKE_FIT) -o $@ --arch $(UIMAGE_ARCH) --os linux \
 413                 --name '$(UIMAGE_NAME)' $(FIT_EXTRA_ARGS) \
 414                 $(if $(findstring 1,$(KBUILD_VERBOSE)),-v) \
 415                 $(if $(FIT_DECOMPOSE_DTBS),--decompose-dtbs) \
 416                 --compress $(FIT_COMPRESSION) -k $< @$(word 2,$^)
 417
 418 # XZ
 419 # ---------------------------------------------------------------------------
 420 # Use xzkern or xzkern_with_size to compress the kernel image and xzmisc to
 421 # compress other things.
 422 #
 423 # xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
 424 # of the kernel decompressor. A BCJ filter is used if it is available for
 425 # the target architecture.
 426 #
 427 # xzkern_with_size also appends uncompressed size of the data using
 428 # size_append. The .xz format has the size information available at the end
 429 # of the file too, but it's in more complex format and it's good to avoid
 430 # changing the part of the boot code that reads the uncompressed size.
 431 # Note that the bytes added by size_append will make the xz tool think that
 432 # the file is corrupt. This is expected.
 433 #
 434 # xzmisc doesn't use size_append, so it can be used to create normal .xz
 435 # files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
 436 # big dictionary would increase the memory usage too much in the multi-call
 437 # decompression mode. A BCJ filter isn't used either.
 438 quiet_cmd_xzkern = XZKERN  $@
 439       cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
 440
 441 quiet_cmd_xzkern_with_size = XZKERN  $@
 442       cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
 443                      $(size_append); } > $@
 444
 445 quiet_cmd_xzmisc = XZMISC  $@
 446       cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
 447
 448 # ZSTD
 449 # ---------------------------------------------------------------------------
 450 # Appends the uncompressed size of the data using size_append. The .zst
 451 # format has the size information available at the beginning of the file too,
 452 # but it's in a more complex format and it's good to avoid changing the part
 453 # of the boot code that reads the uncompressed size.
 454 #
 455 # Note that the bytes added by size_append will make the zstd tool think that
 456 # the file is corrupt. This is expected.
 457 #
 458 # zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
 459 # 128 MB. zstd22 is used for kernel compression because it is decompressed in a
 460 # single pass, so zstd doesn't need to allocate a window buffer. When streaming
 461 # decompression is used, like initramfs decompression, zstd22 should likely not
 462 # be used because it would require zstd to allocate a 128 MB buffer.
 463
 464 quiet_cmd_zstd = ZSTD    $@
 465       cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
 466
 467 quiet_cmd_zstd22 = ZSTD22  $@
 468       cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
 469
 470 quiet_cmd_zstd22_with_size = ZSTD22  $@
 471       cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
 472
 473 # ASM offsets
 474 # ---------------------------------------------------------------------------
 475
 476 # Default sed regexp - multiline due to syntax constraints
 477 #
 478 # Use [:space:] because LLVM's integrated assembler inserts <tab> around
 479 # the .ascii directive whereas GCC keeps the <space> as-is.
 480 define sed-offsets
 481         's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
 482         /^->/{s:->#\(.*\):/* \1 */:; \
 483         s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
 484         s:->::; p;}'
 485 endef
 486
 487 # Use filechk to avoid rebuilds when a header changes, but the resulting file
 488 # does not
 489 define filechk_offsets
 490          echo "#ifndef $2"; \
 491          echo "#define $2"; \
 492          echo "/*"; \
 493          echo " * DO NOT MODIFY."; \
 494          echo " *"; \
 495          echo " * This file was generated by Kbuild"; \
 496          echo " */"; \
 497          echo ""; \
 498          sed -ne $(sed-offsets) < $<; \
 499          echo ""; \
 500          echo "#endif"
 501 endef