1# SPDX-License-Identifier: GPL-2.0 2# Backward compatibility 3asflags-y += $(EXTRA_AFLAGS) 4ccflags-y += $(EXTRA_CFLAGS) 5cppflags-y += $(EXTRA_CPPFLAGS) 6ldflags-y += $(EXTRA_LDFLAGS) 7 8# flags that take effect in current and sub directories 9KBUILD_AFLAGS += $(subdir-asflags-y) 10KBUILD_CFLAGS += $(subdir-ccflags-y) 11KBUILD_RUSTFLAGS += $(subdir-rustflags-y) 12 13# Figure out what we need to build from the various variables 14# =========================================================================== 15 16# When an object is listed to be built compiled-in and modular, 17# only build the compiled-in version 18obj-m := $(filter-out $(obj-y),$(obj-m)) 19 20# Libraries are always collected in one lib file. 21# Filter out objects already built-in 22lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) 23 24# Subdirectories we need to descend into 25subdir-ym := $(sort $(subdir-y) $(subdir-m) \ 26 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m)))) 27 28# Handle objects in subdirs: 29# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and 30# foo/modules.order 31# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order 32# 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. 35 36ifdef need-modorder 37obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m)) 38else 39obj-m := $(filter-out %/, $(obj-m)) 40endif 41 42ifdef need-builtin 43obj-y := $(patsubst %/, %/built-in.a, $(obj-y)) 44else 45obj-y := $(filter-out %/, $(obj-y)) 46endif 47 48# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals 49suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s)))) 50# List composite targets that are constructed by combining other targets 51multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m))) 52# List primitive targets that are compiled from source files 53real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m)) 54 55# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object 56multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y) 57multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m) 58multi-obj-ym := $(multi-obj-y) $(multi-obj-m) 59 60# Replace multi-part objects by their individual parts, 61# including built-in.a from subdirectories 62real-obj-y := $(call real-search, $(obj-y), .o, -objs -y) 63real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m) 64 65always-y += $(always-m) 66 67# hostprogs-always-y += foo 68# ... is a shorthand for 69# hostprogs += foo 70# always-y += foo 71hostprogs += $(hostprogs-always-y) $(hostprogs-always-m) 72always-y += $(hostprogs-always-y) $(hostprogs-always-m) 73 74# userprogs-always-y is likewise. 75userprogs += $(userprogs-always-y) $(userprogs-always-m) 76always-y += $(userprogs-always-y) $(userprogs-always-m) 77 78# Add subdir path 79 80ifneq ($(obj),.) 81extra-y := $(addprefix $(obj)/,$(extra-y)) 82always-y := $(addprefix $(obj)/,$(always-y)) 83targets := $(addprefix $(obj)/,$(targets)) 84obj-m := $(addprefix $(obj)/,$(obj-m)) 85lib-y := $(addprefix $(obj)/,$(lib-y)) 86real-obj-y := $(addprefix $(obj)/,$(real-obj-y)) 87real-obj-m := $(addprefix $(obj)/,$(real-obj-m)) 88multi-obj-m := $(addprefix $(obj)/, $(multi-obj-m)) 89subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) 90endif 91 92# Finds the multi-part object the current object will be linked into. 93# If the object belongs to two or more multi-part objects, list them all. 94modname-multi = $(sort $(foreach m,$(multi-obj-ym),\ 95 $(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=)))) 96 97__modname = $(or $(modname-multi),$(basetarget)) 98 99modname = $(subst $(space),:,$(__modname)) 100modfile = $(addprefix $(obj)/,$(__modname)) 101 102# target with $(obj)/ and its suffix stripped 103target-stem = $(basename $(patsubst $(obj)/%,%,$@)) 104 105# These flags are needed for modversions and compiling, so we define them here 106# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will 107# end up in (or would, if it gets compiled in) 108name-fix-token = $(subst $(comma),_,$(subst -,_,$1)) 109name-fix = $(call stringify,$(call name-fix-token,$1)) 110basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget)) 111modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \ 112 -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname)) 113modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile)) 114 115_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \ 116 $(filter-out $(ccflags-remove-y), \ 117 $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \ 118 $(CFLAGS_$(target-stem).o)) 119_rust_flags = $(filter-out $(RUSTFLAGS_REMOVE_$(target-stem).o), \ 120 $(filter-out $(rustflags-remove-y), \ 121 $(KBUILD_RUSTFLAGS) $(rustflags-y)) \ 122 $(RUSTFLAGS_$(target-stem).o)) 123_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \ 124 $(filter-out $(asflags-remove-y), \ 125 $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \ 126 $(AFLAGS_$(target-stem).o)) 127_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds) 128 129# 130# Enable gcov profiling flags for a file, directory or for all files depending 131# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL 132# (in this order) 133# 134ifeq ($(CONFIG_GCOV_KERNEL),y) 135_c_flags += $(if $(patsubst n%,, \ 136 $(GCOV_PROFILE_$(target-stem).o)$(GCOV_PROFILE)$(if $(is-kernel-object),$(CONFIG_GCOV_PROFILE_ALL))), \ 137 $(CFLAGS_GCOV)) 138endif 139 140# 141# Enable address sanitizer flags for kernel except some files or directories 142# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE) 143# 144ifeq ($(CONFIG_KASAN),y) 145ifneq ($(CONFIG_KASAN_HW_TAGS),y) 146_c_flags += $(if $(patsubst n%,, \ 147 $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \ 148 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE)) 149_rust_flags += $(if $(patsubst n%,, \ 150 $(KASAN_SANITIZE_$(target-stem).o)$(KASAN_SANITIZE)$(is-kernel-object)), \ 151 $(RUSTFLAGS_KASAN)) 152endif 153endif 154 155ifeq ($(CONFIG_KMSAN),y) 156_c_flags += $(if $(patsubst n%,, \ 157 $(KMSAN_SANITIZE_$(target-stem).o)$(KMSAN_SANITIZE)$(is-kernel-object)), \ 158 $(CFLAGS_KMSAN)) 159_c_flags += $(if $(patsubst n%,, \ 160 $(KMSAN_ENABLE_CHECKS_$(target-stem).o)$(KMSAN_ENABLE_CHECKS)$(is-kernel-object)), \ 161 , -mllvm -msan-disable-checks=1) 162endif 163 164ifeq ($(CONFIG_UBSAN),y) 165_c_flags += $(if $(patsubst n%,, \ 166 $(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SANITIZE)$(is-kernel-object)), \ 167 $(CFLAGS_UBSAN)) 168_c_flags += $(if $(patsubst n%,, \ 169 $(UBSAN_SIGNED_WRAP_$(target-stem).o)$(UBSAN_SANITIZE_$(target-stem).o)$(UBSAN_SIGNED_WRAP)$(UBSAN_SANITIZE)$(is-kernel-object)), \ 170 $(CFLAGS_UBSAN_SIGNED_WRAP)) 171endif 172 173ifeq ($(CONFIG_KCOV),y) 174_c_flags += $(if $(patsubst n%,, \ 175 $(KCOV_INSTRUMENT_$(target-stem).o)$(KCOV_INSTRUMENT)$(if $(is-kernel-object),$(CONFIG_KCOV_INSTRUMENT_ALL))), \ 176 $(CFLAGS_KCOV)) 177endif 178 179# 180# Enable KCSAN flags except some files or directories we don't want to check 181# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE) 182# 183ifeq ($(CONFIG_KCSAN),y) 184_c_flags += $(if $(patsubst n%,, \ 185 $(KCSAN_SANITIZE_$(target-stem).o)$(KCSAN_SANITIZE)$(is-kernel-object)), \ 186 $(CFLAGS_KCSAN)) 187# Some uninstrumented files provide implied barriers required to avoid false 188# positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only. 189_c_flags += $(if $(patsubst n%,, \ 190 $(KCSAN_INSTRUMENT_BARRIERS_$(target-stem).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \ 191 -D__KCSAN_INSTRUMENT_BARRIERS__) 192endif 193 194# 195# Enable AutoFDO build flags except some files or directories we don't want to 196# enable (depends on variables AUTOFDO_PROFILE_obj.o and AUTOFDO_PROFILE). 197# 198ifeq ($(CONFIG_AUTOFDO_CLANG),y) 199_c_flags += $(if $(patsubst n%,, \ 200 $(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(is-kernel-object)), \ 201 $(CFLAGS_AUTOFDO_CLANG)) 202endif 203 204# 205# Enable Propeller build flags except some files or directories we don't want to 206# enable (depends on variables AUTOFDO_PROPELLER_obj.o and PROPELLER_PROFILE). 207# 208ifdef CONFIG_PROPELLER_CLANG 209_c_flags += $(if $(patsubst n%,, \ 210 $(AUTOFDO_PROFILE_$(target-stem).o)$(AUTOFDO_PROFILE)$(PROPELLER_PROFILE))$(is-kernel-object), \ 211 $(CFLAGS_PROPELLER_CLANG)) 212endif 213 214# $(src) for including checkin headers from generated source files 215# $(obj) for including generated headers from checkin source files 216ifdef building_out_of_srctree 217_c_flags += $(addprefix -I, $(src) $(obj)) 218_a_flags += $(addprefix -I, $(src) $(obj)) 219_cpp_flags += $(addprefix -I, $(src) $(obj)) 220endif 221 222# If $(is-kernel-object) is 'y', this object will be linked to vmlinux or modules 223is-kernel-object = $(or $(part-of-builtin),$(part-of-module)) 224 225part-of-builtin = $(if $(filter $(basename $@).o, $(real-obj-y) $(lib-y)),y) 226part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y) 227quiet_modtag = $(if $(part-of-module),[M], ) 228 229modkern_cflags = \ 230 $(if $(part-of-module), \ 231 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \ 232 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags)) 233 234modkern_rustflags = \ 235 $(if $(part-of-module), \ 236 $(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \ 237 $(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL)) 238 239modkern_aflags = $(if $(part-of-module), \ 240 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \ 241 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL) $(modfile_flags)) 242 243c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 244 -include $(srctree)/include/linux/compiler_types.h \ 245 $(_c_flags) $(modkern_cflags) \ 246 $(basename_flags) $(modname_flags) 247 248rust_flags = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg 249 250a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 251 $(_a_flags) $(modkern_aflags) $(modname_flags) 252 253cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \ 254 $(_cpp_flags) 255 256ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F)) 257 258ifdef CONFIG_OBJTOOL 259 260objtool := $(objtree)/tools/objtool/objtool 261 262objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK) += --hacks=jump_label 263objtool-args-$(CONFIG_HAVE_NOINSTR_HACK) += --hacks=noinstr 264objtool-args-$(CONFIG_MITIGATION_CALL_DEPTH_TRACKING) += --hacks=skylake 265objtool-args-$(CONFIG_X86_KERNEL_IBT) += --ibt 266objtool-args-$(CONFIG_FINEIBT) += --cfi 267objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL) += --mcount 268ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL 269objtool-args-$(CONFIG_HAVE_OBJTOOL_NOP_MCOUNT) += --mnop 270endif 271objtool-args-$(CONFIG_UNWINDER_ORC) += --orc 272objtool-args-$(CONFIG_MITIGATION_RETPOLINE) += --retpoline 273objtool-args-$(CONFIG_MITIGATION_RETHUNK) += --rethunk 274objtool-args-$(CONFIG_MITIGATION_SLS) += --sls 275objtool-args-$(CONFIG_STACK_VALIDATION) += --stackval 276objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call 277objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess 278objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable 279objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES) 280 281objtool-args = $(objtool-args-y) \ 282 $(if $(delay-objtool), --link) \ 283 $(if $(part-of-module), --module) 284 285delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT)) 286 287cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@) 288cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd) 289 290objtool-enabled := y 291 292endif # CONFIG_OBJTOOL 293 294# Useful for describing the dependency of composite objects 295# Usage: 296# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add) 297define multi_depend 298$(foreach m, $1, \ 299 $(eval $m: \ 300 $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3)))) 301endef 302 303# Build commands 304# =========================================================================== 305# These are shared by some Makefile.* files. 306 307ifdef CONFIG_LTO_CLANG 308# Run $(LD) here to convert LLVM IR to ELF in the following cases: 309# - when this object needs objtool processing, as objtool cannot process LLVM IR 310# - when this is a single-object module, as modpost cannot process LLVM IR 311cmd_ld_single = $(if $(objtool-enabled)$(is-single-obj-m), ; $(LD) $(ld_flags) -r -o $(tmp-target) $@; mv $(tmp-target) $@) 312endif 313 314quiet_cmd_cc_o_c = CC $(quiet_modtag) $@ 315 cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $< \ 316 $(cmd_ld_single) \ 317 $(cmd_objtool) 318 319define rule_cc_o_c 320 $(call cmd_and_fixdep,cc_o_c) 321 $(call cmd,checksrc) 322 $(call cmd,checkdoc) 323 $(call cmd,gen_objtooldep) 324 $(call cmd,gen_symversions_c) 325 $(call cmd,record_mcount) 326 $(call cmd,warn_shared_object) 327endef 328 329quiet_cmd_as_o_S = AS $(quiet_modtag) $@ 330 cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $< $(cmd_objtool) 331 332define rule_as_o_S 333 $(call cmd_and_fixdep,as_o_S) 334 $(call cmd,gen_objtooldep) 335 $(call cmd,gen_symversions_S) 336 $(call cmd,warn_shared_object) 337endef 338 339# Copy a file 340# =========================================================================== 341# 'cp' preserves permissions. If you use it to copy a file in read-only srctree, 342# the copy would be read-only as well, leading to an error when executing the 343# rule next time. Use 'cat' instead in order to generate a writable file. 344quiet_cmd_copy = COPY $@ 345 cmd_copy = cat $< > $@ 346 347$(obj)/%: $(src)/%_shipped 348 $(call cmd,copy) 349 350# Commands useful for building a boot image 351# =========================================================================== 352# 353# Use as following: 354# 355# target: source(s) FORCE 356# $(if_changed,ld/objcopy/gzip) 357# 358# and add target to 'targets' so that we know we have to 359# read in the saved command line 360 361# Linking 362# --------------------------------------------------------------------------- 363 364quiet_cmd_ld = LD $@ 365 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@ 366 367# Archive 368# --------------------------------------------------------------------------- 369 370quiet_cmd_ar = AR $@ 371 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs) 372 373# Objcopy 374# --------------------------------------------------------------------------- 375 376quiet_cmd_objcopy = OBJCOPY $@ 377cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@ 378 379quiet_cmd_strip_relocs = RSTRIP $@ 380cmd_strip_relocs = $(OBJCOPY) --remove-section='.rel*' $@ 381 382# Gzip 383# --------------------------------------------------------------------------- 384 385quiet_cmd_gzip = GZIP $@ 386 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@ 387 388# Bzip2 389# --------------------------------------------------------------------------- 390 391# Bzip2 and LZMA do not include size in file... so we have to fake that; 392# append the size as a 32-bit littleendian number as gzip does. 393size_append = printf $(shell \ 394dec_size=0; \ 395for F in $(real-prereqs); do \ 396 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \ 397 dec_size=$$(expr $$dec_size + $$fsize); \ 398done; \ 399printf "%08x\n" $$dec_size | \ 400 sed 's/\(..\)/\1 /g' | { \ 401 read ch0 ch1 ch2 ch3; \ 402 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \ 403 printf '%s%03o' '\\' $$((0x$$ch)); \ 404 done; \ 405 } \ 406) 407 408quiet_cmd_file_size = GEN $@ 409 cmd_file_size = $(size_append) > $@ 410 411quiet_cmd_bzip2 = BZIP2 $@ 412 cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@ 413 414quiet_cmd_bzip2_with_size = BZIP2 $@ 415 cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@ 416 417# Lzma 418# --------------------------------------------------------------------------- 419 420quiet_cmd_lzma = LZMA $@ 421 cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@ 422 423quiet_cmd_lzma_with_size = LZMA $@ 424 cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@ 425 426quiet_cmd_lzo = LZO $@ 427 cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@ 428 429quiet_cmd_lzo_with_size = LZO $@ 430 cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@ 431 432quiet_cmd_lz4 = LZ4 $@ 433 cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -9 - - > $@ 434 435quiet_cmd_lz4_with_size = LZ4 $@ 436 cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -9 - -; \ 437 $(size_append); } > $@ 438 439# U-Boot mkimage 440# --------------------------------------------------------------------------- 441 442MKIMAGE := $(srctree)/scripts/mkuboot.sh 443 444# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces 445# the number of overrides in arch makefiles 446UIMAGE_ARCH ?= $(SRCARCH) 447UIMAGE_COMPRESSION ?= $(or $(2),none) 448UIMAGE_OPTS-y ?= 449UIMAGE_TYPE ?= kernel 450UIMAGE_LOADADDR ?= arch_must_set_this 451UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR) 452UIMAGE_NAME ?= Linux-$(KERNELRELEASE) 453 454quiet_cmd_uimage = UIMAGE $@ 455 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \ 456 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \ 457 -T $(UIMAGE_TYPE) \ 458 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \ 459 -n '$(UIMAGE_NAME)' -d $< $@ 460 461# Flat Image Tree (FIT) 462# This allows for packaging of a kernel and all devicetrees files, using 463# compression. 464# --------------------------------------------------------------------------- 465 466MAKE_FIT := $(srctree)/scripts/make_fit.py 467 468# Use this to override the compression algorithm 469FIT_COMPRESSION ?= gzip 470 471quiet_cmd_fit = FIT $@ 472 cmd_fit = $(MAKE_FIT) -o $@ --arch $(UIMAGE_ARCH) --os linux \ 473 --name '$(UIMAGE_NAME)' \ 474 $(if $(findstring 1,$(KBUILD_VERBOSE)),-v) \ 475 $(if $(FIT_DECOMPOSE_DTBS),--decompose-dtbs) \ 476 --compress $(FIT_COMPRESSION) -k $< @$(word 2,$^) 477 478# XZ 479# --------------------------------------------------------------------------- 480# Use xzkern or xzkern_with_size to compress the kernel image and xzmisc to 481# compress other things. 482# 483# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage 484# of the kernel decompressor. A BCJ filter is used if it is available for 485# the target architecture. 486# 487# xzkern_with_size also appends uncompressed size of the data using 488# size_append. The .xz format has the size information available at the end 489# of the file too, but it's in more complex format and it's good to avoid 490# changing the part of the boot code that reads the uncompressed size. 491# Note that the bytes added by size_append will make the xz tool think that 492# the file is corrupt. This is expected. 493# 494# xzmisc doesn't use size_append, so it can be used to create normal .xz 495# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very 496# big dictionary would increase the memory usage too much in the multi-call 497# decompression mode. A BCJ filter isn't used either. 498quiet_cmd_xzkern = XZKERN $@ 499 cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@ 500 501quiet_cmd_xzkern_with_size = XZKERN $@ 502 cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \ 503 $(size_append); } > $@ 504 505quiet_cmd_xzmisc = XZMISC $@ 506 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@ 507 508# ZSTD 509# --------------------------------------------------------------------------- 510# Appends the uncompressed size of the data using size_append. The .zst 511# format has the size information available at the beginning of the file too, 512# but it's in a more complex format and it's good to avoid changing the part 513# of the boot code that reads the uncompressed size. 514# 515# Note that the bytes added by size_append will make the zstd tool think that 516# the file is corrupt. This is expected. 517# 518# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of 519# 128 MB. zstd22 is used for kernel compression because it is decompressed in a 520# single pass, so zstd doesn't need to allocate a window buffer. When streaming 521# decompression is used, like initramfs decompression, zstd22 should likely not 522# be used because it would require zstd to allocate a 128 MB buffer. 523 524quiet_cmd_zstd = ZSTD $@ 525 cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@ 526 527quiet_cmd_zstd22 = ZSTD22 $@ 528 cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@ 529 530quiet_cmd_zstd22_with_size = ZSTD22 $@ 531 cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@ 532 533# ASM offsets 534# --------------------------------------------------------------------------- 535 536# Default sed regexp - multiline due to syntax constraints 537# 538# Use [:space:] because LLVM's integrated assembler inserts <tab> around 539# the .ascii directive whereas GCC keeps the <space> as-is. 540define sed-offsets 541 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \ 542 /^->/{s:->#\(.*\):/* \1 */:; \ 543 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \ 544 s:->::; p;}' 545endef 546 547# Use filechk to avoid rebuilds when a header changes, but the resulting file 548# does not 549define filechk_offsets 550 echo "#ifndef $2"; \ 551 echo "#define $2"; \ 552 echo "/*"; \ 553 echo " * DO NOT MODIFY."; \ 554 echo " *"; \ 555 echo " * This file was generated by Kbuild"; \ 556 echo " */"; \ 557 echo ""; \ 558 sed -ne $(sed-offsets) < $<; \ 559 echo ""; \ 560 echo "#endif" 561endef 562