xref: /linux/scripts/Makefile.lib (revision 83439a0f1ce6a592f95e41338320b5f01b98a356)
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) $(userprogs-always-m)
77
78# DTB
79# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
80dtb-$(CONFIG_OF_ALL_DTBS)       += $(dtb-)
81
82# Composite DTB (i.e. DTB constructed by overlay)
83multi-dtb-y := $(call multi-search, $(dtb-y), .dtb, -dtbs)
84# Primitive DTB compiled from *.dts
85real-dtb-y := $(call real-search, $(dtb-y), .dtb, -dtbs)
86# Base DTB that overlay is applied onto (each first word of $(*-dtbs) expansion)
87base-dtb-y := $(foreach m, $(multi-dtb-y), $(firstword $(call suffix-search, $m, .dtb, -dtbs)))
88
89always-y			+= $(dtb-y)
90
91# Add subdir path
92
93ifneq ($(obj),.)
94extra-y		:= $(addprefix $(obj)/,$(extra-y))
95always-y	:= $(addprefix $(obj)/,$(always-y))
96targets		:= $(addprefix $(obj)/,$(targets))
97obj-m		:= $(addprefix $(obj)/,$(obj-m))
98lib-y		:= $(addprefix $(obj)/,$(lib-y))
99real-obj-y	:= $(addprefix $(obj)/,$(real-obj-y))
100real-obj-m	:= $(addprefix $(obj)/,$(real-obj-m))
101multi-obj-m	:= $(addprefix $(obj)/, $(multi-obj-m))
102multi-dtb-y	:= $(addprefix $(obj)/, $(multi-dtb-y))
103real-dtb-y	:= $(addprefix $(obj)/, $(real-dtb-y))
104subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))
105endif
106
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.
109modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
110		$(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))
111
112__modname = $(or $(modname-multi),$(basetarget))
113
114modname = $(subst $(space),:,$(__modname))
115modfile = $(addprefix $(obj)/,$(__modname))
116
117# target with $(obj)/ and its suffix stripped
118target-stem = $(basename $(patsubst $(obj)/%,%,$@))
119
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)
123name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
124name-fix = $(call stringify,$(call name-fix-token,$1))
125basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
126modname_flags  = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
127		 -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
128modfile_flags  = -DKBUILD_MODFILE=$(call stringify,$(modfile))
129
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)
143
144#
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
147# (in this order)
148#
149ifeq ($(CONFIG_GCOV_KERNEL),y)
150_c_flags += $(if $(patsubst n%,, \
151		$(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
152		$(CFLAGS_GCOV))
153endif
154
155#
156# Enable address sanitizer flags for kernel except some files or directories
157# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
158#
159ifeq ($(CONFIG_KASAN),y)
160ifneq ($(CONFIG_KASAN_HW_TAGS),y)
161_c_flags += $(if $(patsubst n%,, \
162		$(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
163		$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
164endif
165endif
166
167ifeq ($(CONFIG_UBSAN),y)
168_c_flags += $(if $(patsubst n%,, \
169		$(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
170		$(CFLAGS_UBSAN))
171endif
172
173ifeq ($(CONFIG_KCOV),y)
174_c_flags += $(if $(patsubst n%,, \
175	$(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(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	$(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \
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	$(KCSAN_INSTRUMENT_BARRIERS_$(basetarget).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
191	-D__KCSAN_INSTRUMENT_BARRIERS__)
192endif
193
194# $(srctree)/$(src) for including checkin headers from generated source files
195# $(objtree)/$(obj) for including generated headers from checkin source files
196ifeq ($(KBUILD_EXTMOD),)
197ifdef building_out_of_srctree
198_c_flags   += -I $(srctree)/$(src) -I $(objtree)/$(obj)
199_a_flags   += -I $(srctree)/$(src) -I $(objtree)/$(obj)
200_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
201endif
202endif
203
204part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
205quiet_modtag = $(if $(part-of-module),[M],   )
206
207modkern_cflags =                                          \
208	$(if $(part-of-module),                           \
209		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
210		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
211
212modkern_rustflags =                                              \
213	$(if $(part-of-module),                                   \
214		$(KBUILD_RUSTFLAGS_MODULE) $(RUSTFLAGS_MODULE), \
215		$(KBUILD_RUSTFLAGS_KERNEL) $(RUSTFLAGS_KERNEL))
216
217modkern_aflags = $(if $(part-of-module),				\
218			$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE),	\
219			$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
220
221c_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
222		 -include $(srctree)/include/linux/compiler_types.h       \
223		 $(_c_flags) $(modkern_cflags)                           \
224		 $(basename_flags) $(modname_flags)
225
226rust_flags     = $(_rust_flags) $(modkern_rustflags) @$(objtree)/include/generated/rustc_cfg
227
228a_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
229		 $(_a_flags) $(modkern_aflags)
230
231cpp_flags      = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
232		 $(_cpp_flags)
233
234ld_flags       = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
235
236DTC_INCLUDE    := $(srctree)/scripts/dtc/include-prefixes
237
238dtc_cpp_flags  = -Wp,-MMD,$(depfile).pre.tmp -nostdinc                    \
239		 $(addprefix -I,$(DTC_INCLUDE))                          \
240		 -undef -D__DTS__
241
242ifdef CONFIG_OBJTOOL
243
244objtool := $(objtree)/tools/objtool/objtool
245
246objtool-args-$(CONFIG_HAVE_JUMP_LABEL_HACK)		+= --hacks=jump_label
247objtool-args-$(CONFIG_HAVE_NOINSTR_HACK)		+= --hacks=noinstr
248objtool-args-$(CONFIG_X86_KERNEL_IBT)			+= --ibt
249objtool-args-$(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL)	+= --mcount
250objtool-args-$(CONFIG_UNWINDER_ORC)			+= --orc
251objtool-args-$(CONFIG_RETPOLINE)			+= --retpoline
252objtool-args-$(CONFIG_RETHUNK)				+= --rethunk
253objtool-args-$(CONFIG_SLS)				+= --sls
254objtool-args-$(CONFIG_STACK_VALIDATION)			+= --stackval
255objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE)		+= --static-call
256objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION)		+= --uaccess
257objtool-args-$(CONFIG_GCOV_KERNEL)			+= --no-unreachable
258
259objtool-args = $(objtool-args-y)					\
260	$(if $(delay-objtool), --link)					\
261	$(if $(part-of-module), --module)
262
263delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
264
265cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool-args) $@)
266cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
267
268endif # CONFIG_OBJTOOL
269
270# Useful for describing the dependency of composite objects
271# Usage:
272#   $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
273define multi_depend
274$(foreach m, $1, \
275	$(eval $m: \
276	$(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
277endef
278
279# Copy a file
280# ===========================================================================
281# 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
282# the copy would be read-only as well, leading to an error when executing the
283# rule next time. Use 'cat' instead in order to generate a writable file.
284quiet_cmd_copy = COPY    $@
285      cmd_copy = cat $< > $@
286
287$(obj)/%: $(src)/%_shipped
288	$(call cmd,copy)
289
290# Commands useful for building a boot image
291# ===========================================================================
292#
293#	Use as following:
294#
295#	target: source(s) FORCE
296#		$(if_changed,ld/objcopy/gzip)
297#
298#	and add target to 'targets' so that we know we have to
299#	read in the saved command line
300
301# Linking
302# ---------------------------------------------------------------------------
303
304quiet_cmd_ld = LD      $@
305      cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
306
307# Archive
308# ---------------------------------------------------------------------------
309
310quiet_cmd_ar = AR      $@
311      cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
312
313# Objcopy
314# ---------------------------------------------------------------------------
315
316quiet_cmd_objcopy = OBJCOPY $@
317cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
318
319# Gzip
320# ---------------------------------------------------------------------------
321
322quiet_cmd_gzip = GZIP    $@
323      cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
324
325# DTC
326# ---------------------------------------------------------------------------
327DTC ?= $(objtree)/scripts/dtc/dtc
328DTC_FLAGS += -Wno-interrupt_provider
329
330# Disable noisy checks by default
331ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
332DTC_FLAGS += -Wno-unit_address_vs_reg \
333	-Wno-avoid_unnecessary_addr_size \
334	-Wno-alias_paths \
335	-Wno-graph_child_address \
336	-Wno-simple_bus_reg \
337	-Wno-unique_unit_address
338endif
339
340ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
341DTC_FLAGS += -Wnode_name_chars_strict \
342	-Wproperty_name_chars_strict \
343	-Winterrupt_provider
344endif
345
346DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
347
348# Set -@ if the target is a base DTB that overlay is applied onto
349DTC_FLAGS += $(if $(filter $(patsubst $(obj)/%,%,$@), $(base-dtb-y)), -@)
350
351# Generate an assembly file to wrap the output of the device tree compiler
352quiet_cmd_dt_S_dtb= DTB     $@
353cmd_dt_S_dtb=						\
354{							\
355	echo '\#include <asm-generic/vmlinux.lds.h>'; 	\
356	echo '.section .dtb.init.rodata,"a"';		\
357	echo '.balign STRUCT_ALIGNMENT';		\
358	echo '.global __dtb_$(subst -,_,$(*F))_begin';	\
359	echo '__dtb_$(subst -,_,$(*F))_begin:';		\
360	echo '.incbin "$<" ';				\
361	echo '__dtb_$(subst -,_,$(*F))_end:';		\
362	echo '.global __dtb_$(subst -,_,$(*F))_end';	\
363	echo '.balign STRUCT_ALIGNMENT'; 		\
364} > $@
365
366$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
367	$(call if_changed,dt_S_dtb)
368
369quiet_cmd_dtc = DTC     $@
370cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
371	$(DTC) -o $@ -b 0 \
372		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
373		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
374	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
375
376quiet_cmd_fdtoverlay = DTOVL   $@
377      cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
378
379$(multi-dtb-y): FORCE
380	$(call if_changed,fdtoverlay)
381$(call multi_depend, $(multi-dtb-y), .dtb, -dtbs)
382
383ifneq ($(CHECK_DTBS)$(CHECK_DT_BINDING),)
384DT_CHECKER ?= dt-validate
385DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m)
386DT_BINDING_DIR := Documentation/devicetree/bindings
387DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
388
389quiet_cmd_dtb =	DTC_CHK $@
390      cmd_dtb =	$(cmd_dtc) ; $(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true
391else
392quiet_cmd_dtb = $(quiet_cmd_dtc)
393      cmd_dtb = $(cmd_dtc)
394endif
395
396$(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
397	$(call if_changed_dep,dtb)
398
399$(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE
400	$(call if_changed_dep,dtc)
401
402dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
403
404# Bzip2
405# ---------------------------------------------------------------------------
406
407# Bzip2 and LZMA do not include size in file... so we have to fake that;
408# append the size as a 32-bit littleendian number as gzip does.
409size_append = printf $(shell						\
410dec_size=0;								\
411for F in $(real-prereqs); do					\
412	fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F);	\
413	dec_size=$$(expr $$dec_size + $$fsize);				\
414done;									\
415printf "%08x\n" $$dec_size |						\
416	sed 's/\(..\)/\1 /g' | {					\
417		read ch0 ch1 ch2 ch3;					\
418		for ch in $$ch3 $$ch2 $$ch1 $$ch0; do			\
419			printf '%s%03o' '\\' $$((0x$$ch)); 		\
420		done;							\
421	}								\
422)
423
424quiet_cmd_file_size = GEN     $@
425      cmd_file_size = $(size_append) > $@
426
427quiet_cmd_bzip2 = BZIP2   $@
428      cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
429
430quiet_cmd_bzip2_with_size = BZIP2   $@
431      cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
432
433# Lzma
434# ---------------------------------------------------------------------------
435
436quiet_cmd_lzma = LZMA    $@
437      cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
438
439quiet_cmd_lzma_with_size = LZMA    $@
440      cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
441
442quiet_cmd_lzo = LZO     $@
443      cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
444
445quiet_cmd_lzo_with_size = LZO     $@
446      cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
447
448quiet_cmd_lz4 = LZ4     $@
449      cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@
450
451quiet_cmd_lz4_with_size = LZ4     $@
452      cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
453                  $(size_append); } > $@
454
455# U-Boot mkimage
456# ---------------------------------------------------------------------------
457
458MKIMAGE := $(srctree)/scripts/mkuboot.sh
459
460# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
461# the number of overrides in arch makefiles
462UIMAGE_ARCH ?= $(SRCARCH)
463UIMAGE_COMPRESSION ?= $(or $(2),none)
464UIMAGE_OPTS-y ?=
465UIMAGE_TYPE ?= kernel
466UIMAGE_LOADADDR ?= arch_must_set_this
467UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
468UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
469
470quiet_cmd_uimage = UIMAGE  $@
471      cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
472			-C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
473			-T $(UIMAGE_TYPE) \
474			-a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
475			-n $(UIMAGE_NAME) -d $< $@
476
477# XZ
478# ---------------------------------------------------------------------------
479# Use xzkern to compress the kernel image and xzmisc to compress other things.
480#
481# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
482# of the kernel decompressor. A BCJ filter is used if it is available for
483# the target architecture. xzkern also appends uncompressed size of the data
484# using size_append. The .xz format has the size information available at
485# the end of the file too, but it's in more complex format and it's good to
486# avoid changing the part of the boot code that reads the uncompressed size.
487# Note that the bytes added by size_append will make the xz tool think that
488# the file is corrupt. This is expected.
489#
490# xzmisc doesn't use size_append, so it can be used to create normal .xz
491# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
492# big dictionary would increase the memory usage too much in the multi-call
493# decompression mode. A BCJ filter isn't used either.
494quiet_cmd_xzkern = XZKERN  $@
495      cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
496
497quiet_cmd_xzkern_with_size = XZKERN  $@
498      cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
499                     $(size_append); } > $@
500
501quiet_cmd_xzmisc = XZMISC  $@
502      cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
503
504# ZSTD
505# ---------------------------------------------------------------------------
506# Appends the uncompressed size of the data using size_append. The .zst
507# format has the size information available at the beginning of the file too,
508# but it's in a more complex format and it's good to avoid changing the part
509# of the boot code that reads the uncompressed size.
510#
511# Note that the bytes added by size_append will make the zstd tool think that
512# the file is corrupt. This is expected.
513#
514# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
515# 128 MB. zstd22 is used for kernel compression because it is decompressed in a
516# single pass, so zstd doesn't need to allocate a window buffer. When streaming
517# decompression is used, like initramfs decompression, zstd22 should likely not
518# be used because it would require zstd to allocate a 128 MB buffer.
519
520quiet_cmd_zstd = ZSTD    $@
521      cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
522
523quiet_cmd_zstd22 = ZSTD22  $@
524      cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
525
526quiet_cmd_zstd22_with_size = ZSTD22  $@
527      cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
528
529# ASM offsets
530# ---------------------------------------------------------------------------
531
532# Default sed regexp - multiline due to syntax constraints
533#
534# Use [:space:] because LLVM's integrated assembler inserts <tab> around
535# the .ascii directive whereas GCC keeps the <space> as-is.
536define sed-offsets
537	's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
538	/^->/{s:->#\(.*\):/* \1 */:; \
539	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
540	s:->::; p;}'
541endef
542
543# Use filechk to avoid rebuilds when a header changes, but the resulting file
544# does not
545define filechk_offsets
546	 echo "#ifndef $2"; \
547	 echo "#define $2"; \
548	 echo "/*"; \
549	 echo " * DO NOT MODIFY."; \
550	 echo " *"; \
551	 echo " * This file was generated by Kbuild"; \
552	 echo " */"; \
553	 echo ""; \
554	 sed -ne $(sed-offsets) < $<; \
555	 echo ""; \
556	 echo "#endif"
557endef
558