xref: /openbmc/linux/scripts/Makefile.lib (revision 1a340825)
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)
11
12# Figure out what we need to build from the various variables
13# ===========================================================================
14
15# When an object is listed to be built compiled-in and modular,
16# only build the compiled-in version
17obj-m := $(filter-out $(obj-y),$(obj-m))
18
19# Libraries are always collected in one lib file.
20# Filter out objects already built-in
21lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
22
23# Subdirectories we need to descend into
24subdir-ym := $(sort $(subdir-y) $(subdir-m) \
25			$(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
26
27# Handle objects in subdirs:
28# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
29#   foo/modules.order
30# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
31#
32# Generate modules.order to determine modorder. Unfortunately, we don't have
33# information about ordering between -y and -m subdirs. Just put -y's first.
34
35ifdef need-modorder
36obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
37else
38obj-m := $(filter-out %/, $(obj-m))
39endif
40
41ifdef need-builtin
42obj-y		:= $(patsubst %/, %/built-in.a, $(obj-y))
43else
44obj-y		:= $(filter-out %/, $(obj-y))
45endif
46
47# Expand $(foo-objs) $(foo-y) etc. by replacing their individuals
48suffix-search = $(strip $(foreach s, $3, $($(1:%$(strip $2)=%$s))))
49# List composite targets that are constructed by combining other targets
50multi-search = $(sort $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $m)))
51# List primitive targets that are compiled from source files
52real-search = $(foreach m, $1, $(if $(call suffix-search, $m, $2, $3 -), $(call suffix-search, $m, $2, $3), $m))
53
54# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
55multi-obj-y := $(call multi-search, $(obj-y), .o, -objs -y)
56multi-obj-m := $(call multi-search, $(obj-m), .o, -objs -y -m)
57multi-obj-ym := $(multi-obj-y) $(multi-obj-m)
58
59# Replace multi-part objects by their individual parts,
60# including built-in.a from subdirectories
61real-obj-y := $(call real-search, $(obj-y), .o, -objs -y)
62real-obj-m := $(call real-search, $(obj-m), .o, -objs -y -m)
63
64always-y += $(always-m)
65
66# hostprogs-always-y += foo
67# ... is a shorthand for
68# hostprogs += foo
69# always-y  += foo
70hostprogs += $(hostprogs-always-y) $(hostprogs-always-m)
71always-y += $(hostprogs-always-y) $(hostprogs-always-m)
72
73# userprogs-always-y is likewise.
74userprogs += $(userprogs-always-y) $(userprogs-always-m)
75always-y += $(userprogs-always-y) $(userprogs-always-m)
76
77# DTB
78# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
79dtb-$(CONFIG_OF_ALL_DTBS)       += $(dtb-)
80
81# Composite DTB (i.e. DTB constructed by overlay)
82multi-dtb-y := $(call multi-search, $(dtb-y), .dtb, -dtbs)
83# Primitive DTB compiled from *.dts
84real-dtb-y := $(call real-search, $(dtb-y), .dtb, -dtbs)
85# Base DTB that overlay is applied onto (each first word of $(*-dtbs) expansion)
86base-dtb-y := $(foreach m, $(multi-dtb-y), $(firstword $(call suffix-search, $m, .dtb, -dtbs)))
87
88always-y			+= $(dtb-y)
89
90# Add subdir path
91
92extra-y		:= $(addprefix $(obj)/,$(extra-y))
93always-y	:= $(addprefix $(obj)/,$(always-y))
94targets		:= $(addprefix $(obj)/,$(targets))
95obj-m		:= $(addprefix $(obj)/,$(obj-m))
96lib-y		:= $(addprefix $(obj)/,$(lib-y))
97real-obj-y	:= $(addprefix $(obj)/,$(real-obj-y))
98real-obj-m	:= $(addprefix $(obj)/,$(real-obj-m))
99multi-obj-m	:= $(addprefix $(obj)/, $(multi-obj-m))
100multi-dtb-y	:= $(addprefix $(obj)/, $(multi-dtb-y))
101real-dtb-y	:= $(addprefix $(obj)/, $(real-dtb-y))
102subdir-ym	:= $(addprefix $(obj)/,$(subdir-ym))
103
104# Finds the multi-part object the current object will be linked into.
105# If the object belongs to two or more multi-part objects, list them all.
106modname-multi = $(sort $(foreach m,$(multi-obj-ym),\
107		$(if $(filter $*.o, $(call suffix-search, $m, .o, -objs -y -m)),$(m:.o=))))
108
109__modname = $(or $(modname-multi),$(basetarget))
110
111modname = $(subst $(space),:,$(__modname))
112modfile = $(addprefix $(obj)/,$(__modname))
113
114# target with $(obj)/ and its suffix stripped
115target-stem = $(basename $(patsubst $(obj)/%,%,$@))
116
117# These flags are needed for modversions and compiling, so we define them here
118# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
119# end up in (or would, if it gets compiled in)
120name-fix-token = $(subst $(comma),_,$(subst -,_,$1))
121name-fix = $(call stringify,$(call name-fix-token,$1))
122basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
123modname_flags  = -DKBUILD_MODNAME=$(call name-fix,$(modname)) \
124		 -D__KBUILD_MODNAME=kmod_$(call name-fix-token,$(modname))
125modfile_flags  = -DKBUILD_MODFILE=$(call stringify,$(modfile))
126
127_c_flags       = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
128                     $(filter-out $(ccflags-remove-y), \
129                         $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
130                     $(CFLAGS_$(target-stem).o))
131_a_flags       = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), \
132                     $(filter-out $(asflags-remove-y), \
133                         $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(asflags-y)) \
134                     $(AFLAGS_$(target-stem).o))
135_cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
136
137#
138# Enable gcov profiling flags for a file, directory or for all files depending
139# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
140# (in this order)
141#
142ifeq ($(CONFIG_GCOV_KERNEL),y)
143_c_flags += $(if $(patsubst n%,, \
144		$(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
145		$(CFLAGS_GCOV))
146endif
147
148#
149# Enable address sanitizer flags for kernel except some files or directories
150# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
151#
152ifeq ($(CONFIG_KASAN),y)
153ifneq ($(CONFIG_KASAN_HW_TAGS),y)
154_c_flags += $(if $(patsubst n%,, \
155		$(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
156		$(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
157endif
158endif
159
160ifeq ($(CONFIG_UBSAN),y)
161_c_flags += $(if $(patsubst n%,, \
162		$(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
163		$(CFLAGS_UBSAN))
164endif
165
166ifeq ($(CONFIG_KCOV),y)
167_c_flags += $(if $(patsubst n%,, \
168	$(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
169	$(CFLAGS_KCOV))
170endif
171
172#
173# Enable KCSAN flags except some files or directories we don't want to check
174# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
175#
176ifeq ($(CONFIG_KCSAN),y)
177_c_flags += $(if $(patsubst n%,, \
178	$(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \
179	$(CFLAGS_KCSAN))
180# Some uninstrumented files provide implied barriers required to avoid false
181# positives: set KCSAN_INSTRUMENT_BARRIERS for barrier instrumentation only.
182_c_flags += $(if $(patsubst n%,, \
183	$(KCSAN_INSTRUMENT_BARRIERS_$(basetarget).o)$(KCSAN_INSTRUMENT_BARRIERS)n), \
184	-D__KCSAN_INSTRUMENT_BARRIERS__)
185endif
186
187# $(srctree)/$(src) for including checkin headers from generated source files
188# $(objtree)/$(obj) for including generated headers from checkin source files
189ifeq ($(KBUILD_EXTMOD),)
190ifdef building_out_of_srctree
191_c_flags   += -I $(srctree)/$(src) -I $(objtree)/$(obj)
192_a_flags   += -I $(srctree)/$(src) -I $(objtree)/$(obj)
193_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
194endif
195endif
196
197part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
198quiet_modtag = $(if $(part-of-module),[M],   )
199
200modkern_cflags =                                          \
201	$(if $(part-of-module),                           \
202		$(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
203		$(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
204
205modkern_aflags = $(if $(part-of-module),				\
206			$(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE),	\
207			$(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
208
209c_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
210		 -include $(srctree)/include/linux/compiler_types.h       \
211		 $(_c_flags) $(modkern_cflags)                           \
212		 $(basename_flags) $(modname_flags)
213
214a_flags        = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
215		 $(_a_flags) $(modkern_aflags)
216
217cpp_flags      = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
218		 $(_cpp_flags)
219
220ld_flags       = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
221
222DTC_INCLUDE    := $(srctree)/scripts/dtc/include-prefixes
223
224dtc_cpp_flags  = -Wp,-MMD,$(depfile).pre.tmp -nostdinc                    \
225		 $(addprefix -I,$(DTC_INCLUDE))                          \
226		 -undef -D__DTS__
227
228ifdef CONFIG_OBJTOOL
229
230objtool := $(objtree)/tools/objtool/objtool
231
232objtool_args =								\
233	$(if $(CONFIG_HAVE_JUMP_LABEL_HACK), --hacks=jump_label)	\
234	$(if $(CONFIG_HAVE_NOINSTR_HACK), --hacks=noinstr)		\
235	$(if $(CONFIG_X86_KERNEL_IBT), --ibt)				\
236	$(if $(CONFIG_FTRACE_MCOUNT_USE_OBJTOOL), --mcount)		\
237	$(if $(CONFIG_UNWINDER_ORC), --orc)				\
238	$(if $(CONFIG_RETPOLINE), --retpoline)				\
239	$(if $(CONFIG_SLS), --sls)					\
240	$(if $(CONFIG_STACK_VALIDATION), --stackval)			\
241	$(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call)		\
242	$(if $(CONFIG_HAVE_UACCESS_VALIDATION), --uaccess)		\
243	$(if $(delay-objtool), --link)					\
244	$(if $(part-of-module), --module)				\
245	$(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
246
247delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
248
249cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
250cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
251
252endif # CONFIG_OBJTOOL
253
254# Useful for describing the dependency of composite objects
255# Usage:
256#   $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
257define multi_depend
258$(foreach m, $1, \
259	$(eval $m: \
260	$(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
261endef
262
263# Copy a file
264# ===========================================================================
265# 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
266# the copy would be read-only as well, leading to an error when executing the
267# rule next time. Use 'cat' instead in order to generate a writable file.
268quiet_cmd_copy = COPY    $@
269      cmd_copy = cat $< > $@
270
271$(obj)/%: $(src)/%_shipped
272	$(call cmd,copy)
273
274# Commands useful for building a boot image
275# ===========================================================================
276#
277#	Use as following:
278#
279#	target: source(s) FORCE
280#		$(if_changed,ld/objcopy/gzip)
281#
282#	and add target to 'targets' so that we know we have to
283#	read in the saved command line
284
285# Linking
286# ---------------------------------------------------------------------------
287
288quiet_cmd_ld = LD      $@
289      cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
290
291# Archive
292# ---------------------------------------------------------------------------
293
294quiet_cmd_ar = AR      $@
295      cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
296
297# Objcopy
298# ---------------------------------------------------------------------------
299
300quiet_cmd_objcopy = OBJCOPY $@
301cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
302
303# Gzip
304# ---------------------------------------------------------------------------
305
306quiet_cmd_gzip = GZIP    $@
307      cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
308
309# DTC
310# ---------------------------------------------------------------------------
311DTC ?= $(objtree)/scripts/dtc/dtc
312DTC_FLAGS += -Wno-interrupt_provider
313
314# Disable noisy checks by default
315ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
316DTC_FLAGS += -Wno-unit_address_vs_reg \
317	-Wno-avoid_unnecessary_addr_size \
318	-Wno-alias_paths \
319	-Wno-graph_child_address \
320	-Wno-simple_bus_reg \
321	-Wno-unique_unit_address
322endif
323
324ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
325DTC_FLAGS += -Wnode_name_chars_strict \
326	-Wproperty_name_chars_strict \
327	-Winterrupt_provider
328endif
329
330DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
331
332# Set -@ if the target is a base DTB that overlay is applied onto
333DTC_FLAGS += $(if $(filter $(patsubst $(obj)/%,%,$@), $(base-dtb-y)), -@)
334
335# Generate an assembly file to wrap the output of the device tree compiler
336quiet_cmd_dt_S_dtb= DTB     $@
337cmd_dt_S_dtb=						\
338{							\
339	echo '\#include <asm-generic/vmlinux.lds.h>'; 	\
340	echo '.section .dtb.init.rodata,"a"';		\
341	echo '.balign STRUCT_ALIGNMENT';		\
342	echo '.global __dtb_$(subst -,_,$(*F))_begin';	\
343	echo '__dtb_$(subst -,_,$(*F))_begin:';		\
344	echo '.incbin "$<" ';				\
345	echo '__dtb_$(subst -,_,$(*F))_end:';		\
346	echo '.global __dtb_$(subst -,_,$(*F))_end';	\
347	echo '.balign STRUCT_ALIGNMENT'; 		\
348} > $@
349
350$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
351	$(call if_changed,dt_S_dtb)
352
353quiet_cmd_dtc = DTC     $@
354cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
355	$(DTC) -o $@ -b 0 \
356		$(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
357		-d $(depfile).dtc.tmp $(dtc-tmp) ; \
358	cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
359
360quiet_cmd_fdtoverlay = DTOVL   $@
361      cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
362
363$(multi-dtb-y): FORCE
364	$(call if_changed,fdtoverlay)
365$(call multi_depend, $(multi-dtb-y), .dtb, -dtbs)
366
367ifneq ($(CHECK_DTBS)$(CHECK_DT_BINDING),)
368DT_CHECKER ?= dt-validate
369DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m)
370DT_BINDING_DIR := Documentation/devicetree/bindings
371DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
372
373quiet_cmd_dtb_check =	CHECK   $@
374      cmd_dtb_check =	$(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true
375endif
376
377define rule_dtc
378	$(call cmd_and_fixdep,dtc)
379	$(call cmd,dtb_check)
380endef
381
382$(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
383	$(call if_changed_rule,dtc)
384
385$(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE
386	$(call if_changed_dep,dtc)
387
388dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
389
390# Bzip2
391# ---------------------------------------------------------------------------
392
393# Bzip2 and LZMA do not include size in file... so we have to fake that;
394# append the size as a 32-bit littleendian number as gzip does.
395size_append = printf $(shell						\
396dec_size=0;								\
397for F in $(real-prereqs); do					\
398	fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F);	\
399	dec_size=$$(expr $$dec_size + $$fsize);				\
400done;									\
401printf "%08x\n" $$dec_size |						\
402	sed 's/\(..\)/\1 /g' | {					\
403		read ch0 ch1 ch2 ch3;					\
404		for ch in $$ch3 $$ch2 $$ch1 $$ch0; do			\
405			printf '%s%03o' '\\' $$((0x$$ch)); 		\
406		done;							\
407	}								\
408)
409
410quiet_cmd_file_size = GEN     $@
411      cmd_file_size = $(size_append) > $@
412
413quiet_cmd_bzip2 = BZIP2   $@
414      cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
415
416quiet_cmd_bzip2_with_size = BZIP2   $@
417      cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
418
419# Lzma
420# ---------------------------------------------------------------------------
421
422quiet_cmd_lzma = LZMA    $@
423      cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
424
425quiet_cmd_lzma_with_size = LZMA    $@
426      cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
427
428quiet_cmd_lzo = LZO     $@
429      cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
430
431quiet_cmd_lzo_with_size = LZO     $@
432      cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
433
434quiet_cmd_lz4 = LZ4     $@
435      cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@
436
437quiet_cmd_lz4_with_size = LZ4     $@
438      cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
439                  $(size_append); } > $@
440
441# U-Boot mkimage
442# ---------------------------------------------------------------------------
443
444MKIMAGE := $(srctree)/scripts/mkuboot.sh
445
446# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
447# the number of overrides in arch makefiles
448UIMAGE_ARCH ?= $(SRCARCH)
449UIMAGE_COMPRESSION ?= $(or $(2),none)
450UIMAGE_OPTS-y ?=
451UIMAGE_TYPE ?= kernel
452UIMAGE_LOADADDR ?= arch_must_set_this
453UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
454UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
455
456quiet_cmd_uimage = UIMAGE  $@
457      cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
458			-C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
459			-T $(UIMAGE_TYPE) \
460			-a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
461			-n $(UIMAGE_NAME) -d $< $@
462
463# XZ
464# ---------------------------------------------------------------------------
465# Use xzkern to compress the kernel image and xzmisc to compress other things.
466#
467# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
468# of the kernel decompressor. A BCJ filter is used if it is available for
469# the target architecture. xzkern also appends uncompressed size of the data
470# using size_append. The .xz format has the size information available at
471# the end of the file too, but it's in more complex format and it's good to
472# avoid changing the part of the boot code that reads the uncompressed size.
473# Note that the bytes added by size_append will make the xz tool think that
474# the file is corrupt. This is expected.
475#
476# xzmisc doesn't use size_append, so it can be used to create normal .xz
477# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
478# big dictionary would increase the memory usage too much in the multi-call
479# decompression mode. A BCJ filter isn't used either.
480quiet_cmd_xzkern = XZKERN  $@
481      cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
482
483quiet_cmd_xzkern_with_size = XZKERN  $@
484      cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
485                     $(size_append); } > $@
486
487quiet_cmd_xzmisc = XZMISC  $@
488      cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
489
490# ZSTD
491# ---------------------------------------------------------------------------
492# Appends the uncompressed size of the data using size_append. The .zst
493# format has the size information available at the beginning of the file too,
494# but it's in a more complex format and it's good to avoid changing the part
495# of the boot code that reads the uncompressed size.
496#
497# Note that the bytes added by size_append will make the zstd tool think that
498# the file is corrupt. This is expected.
499#
500# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
501# 128 MB. zstd22 is used for kernel compression because it is decompressed in a
502# single pass, so zstd doesn't need to allocate a window buffer. When streaming
503# decompression is used, like initramfs decompression, zstd22 should likely not
504# be used because it would require zstd to allocate a 128 MB buffer.
505
506quiet_cmd_zstd = ZSTD    $@
507      cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
508
509quiet_cmd_zstd22 = ZSTD22  $@
510      cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
511
512quiet_cmd_zstd22_with_size = ZSTD22  $@
513      cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
514
515# ASM offsets
516# ---------------------------------------------------------------------------
517
518# Default sed regexp - multiline due to syntax constraints
519#
520# Use [:space:] because LLVM's integrated assembler inserts <tab> around
521# the .ascii directive whereas GCC keeps the <space> as-is.
522define sed-offsets
523	's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
524	/^->/{s:->#\(.*\):/* \1 */:; \
525	s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
526	s:->::; p;}'
527endef
528
529# Use filechk to avoid rebuilds when a header changes, but the resulting file
530# does not
531define filechk_offsets
532	 echo "#ifndef $2"; \
533	 echo "#define $2"; \
534	 echo "/*"; \
535	 echo " * DO NOT MODIFY."; \
536	 echo " *"; \
537	 echo " * This file was generated by Kbuild"; \
538	 echo " */"; \
539	 echo ""; \
540	 sed -ne $(sed-offsets) < $<; \
541	 echo ""; \
542	 echo "#endif"
543endef
544