Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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_RETHUNK), --rethunk) \
240 $(if $(CONFIG_SLS), --sls) \
241 $(if $(CONFIG_STACK_VALIDATION), --stackval) \
242 $(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call) \
243 $(if $(CONFIG_HAVE_UACCESS_VALIDATION), --uaccess) \
244 $(if $(delay-objtool), --link) \
245 $(if $(part-of-module), --module) \
246 $(if $(CONFIG_GCOV_KERNEL), --no-unreachable)
247
248delay-objtool := $(or $(CONFIG_LTO_CLANG),$(CONFIG_X86_KERNEL_IBT))
249
250cmd_objtool = $(if $(objtool-enabled), ; $(objtool) $(objtool_args) $@)
251cmd_gen_objtooldep = $(if $(objtool-enabled), { echo ; echo '$@: $$(wildcard $(objtool))' ; } >> $(dot-target).cmd)
252
253endif # CONFIG_OBJTOOL
254
255# Useful for describing the dependency of composite objects
256# Usage:
257# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
258define multi_depend
259$(foreach m, $1, \
260 $(eval $m: \
261 $(addprefix $(obj)/, $(call suffix-search, $(patsubst $(obj)/%,%,$m), $2, $3))))
262endef
263
264# Copy a file
265# ===========================================================================
266# 'cp' preserves permissions. If you use it to copy a file in read-only srctree,
267# the copy would be read-only as well, leading to an error when executing the
268# rule next time. Use 'cat' instead in order to generate a writable file.
269quiet_cmd_copy = COPY $@
270 cmd_copy = cat $< > $@
271
272$(obj)/%: $(src)/%_shipped
273 $(call cmd,copy)
274
275# Commands useful for building a boot image
276# ===========================================================================
277#
278# Use as following:
279#
280# target: source(s) FORCE
281# $(if_changed,ld/objcopy/gzip)
282#
283# and add target to 'targets' so that we know we have to
284# read in the saved command line
285
286# Linking
287# ---------------------------------------------------------------------------
288
289quiet_cmd_ld = LD $@
290 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
291
292# Archive
293# ---------------------------------------------------------------------------
294
295quiet_cmd_ar = AR $@
296 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
297
298# Objcopy
299# ---------------------------------------------------------------------------
300
301quiet_cmd_objcopy = OBJCOPY $@
302cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
303
304# Gzip
305# ---------------------------------------------------------------------------
306
307quiet_cmd_gzip = GZIP $@
308 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
309
310# DTC
311# ---------------------------------------------------------------------------
312DTC ?= $(objtree)/scripts/dtc/dtc
313DTC_FLAGS += -Wno-interrupt_provider
314
315# Disable noisy checks by default
316ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
317DTC_FLAGS += -Wno-unit_address_vs_reg \
318 -Wno-avoid_unnecessary_addr_size \
319 -Wno-alias_paths \
320 -Wno-graph_child_address \
321 -Wno-simple_bus_reg \
322 -Wno-unique_unit_address
323endif
324
325ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
326DTC_FLAGS += -Wnode_name_chars_strict \
327 -Wproperty_name_chars_strict \
328 -Winterrupt_provider
329endif
330
331DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
332
333# Set -@ if the target is a base DTB that overlay is applied onto
334DTC_FLAGS += $(if $(filter $(patsubst $(obj)/%,%,$@), $(base-dtb-y)), -@)
335
336# Generate an assembly file to wrap the output of the device tree compiler
337quiet_cmd_dt_S_dtb= DTB $@
338cmd_dt_S_dtb= \
339{ \
340 echo '\#include <asm-generic/vmlinux.lds.h>'; \
341 echo '.section .dtb.init.rodata,"a"'; \
342 echo '.balign STRUCT_ALIGNMENT'; \
343 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
344 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
345 echo '.incbin "$<" '; \
346 echo '__dtb_$(subst -,_,$(*F))_end:'; \
347 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
348 echo '.balign STRUCT_ALIGNMENT'; \
349} > $@
350
351$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
352 $(call if_changed,dt_S_dtb)
353
354quiet_cmd_dtc = DTC $@
355cmd_dtc = $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
356 $(DTC) -o $@ -b 0 \
357 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
358 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
359 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
360
361quiet_cmd_fdtoverlay = DTOVL $@
362 cmd_fdtoverlay = $(objtree)/scripts/dtc/fdtoverlay -o $@ -i $(real-prereqs)
363
364$(multi-dtb-y): FORCE
365 $(call if_changed,fdtoverlay)
366$(call multi_depend, $(multi-dtb-y), .dtb, -dtbs)
367
368ifneq ($(CHECK_DTBS)$(CHECK_DT_BINDING),)
369DT_CHECKER ?= dt-validate
370DT_CHECKER_FLAGS ?= $(if $(DT_SCHEMA_FILES),-l $(DT_SCHEMA_FILES),-m)
371DT_BINDING_DIR := Documentation/devicetree/bindings
372DT_TMP_SCHEMA := $(objtree)/$(DT_BINDING_DIR)/processed-schema.json
373
374quiet_cmd_dtb_check = CHECK $@
375 cmd_dtb_check = $(DT_CHECKER) $(DT_CHECKER_FLAGS) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@ || true
376endif
377
378define rule_dtc
379 $(call cmd_and_fixdep,dtc)
380 $(call cmd,dtb_check)
381endef
382
383$(obj)/%.dtb: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
384 $(call if_changed_rule,dtc)
385
386$(obj)/%.dtbo: $(src)/%.dts $(DTC) FORCE
387 $(call if_changed_dep,dtc)
388
389dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
390
391# Bzip2
392# ---------------------------------------------------------------------------
393
394# Bzip2 and LZMA do not include size in file... so we have to fake that;
395# append the size as a 32-bit littleendian number as gzip does.
396size_append = printf $(shell \
397dec_size=0; \
398for F in $(real-prereqs); do \
399 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
400 dec_size=$$(expr $$dec_size + $$fsize); \
401done; \
402printf "%08x\n" $$dec_size | \
403 sed 's/\(..\)/\1 /g' | { \
404 read ch0 ch1 ch2 ch3; \
405 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
406 printf '%s%03o' '\\' $$((0x$$ch)); \
407 done; \
408 } \
409)
410
411quiet_cmd_file_size = GEN $@
412 cmd_file_size = $(size_append) > $@
413
414quiet_cmd_bzip2 = BZIP2 $@
415 cmd_bzip2 = cat $(real-prereqs) | $(KBZIP2) -9 > $@
416
417quiet_cmd_bzip2_with_size = BZIP2 $@
418 cmd_bzip2_with_size = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
419
420# Lzma
421# ---------------------------------------------------------------------------
422
423quiet_cmd_lzma = LZMA $@
424 cmd_lzma = cat $(real-prereqs) | $(LZMA) -9 > $@
425
426quiet_cmd_lzma_with_size = LZMA $@
427 cmd_lzma_with_size = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
428
429quiet_cmd_lzo = LZO $@
430 cmd_lzo = cat $(real-prereqs) | $(KLZOP) -9 > $@
431
432quiet_cmd_lzo_with_size = LZO $@
433 cmd_lzo_with_size = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
434
435quiet_cmd_lz4 = LZ4 $@
436 cmd_lz4 = cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout > $@
437
438quiet_cmd_lz4_with_size = LZ4 $@
439 cmd_lz4_with_size = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
440 $(size_append); } > $@
441
442# U-Boot mkimage
443# ---------------------------------------------------------------------------
444
445MKIMAGE := $(srctree)/scripts/mkuboot.sh
446
447# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
448# the number of overrides in arch makefiles
449UIMAGE_ARCH ?= $(SRCARCH)
450UIMAGE_COMPRESSION ?= $(or $(2),none)
451UIMAGE_OPTS-y ?=
452UIMAGE_TYPE ?= kernel
453UIMAGE_LOADADDR ?= arch_must_set_this
454UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
455UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
456
457quiet_cmd_uimage = UIMAGE $@
458 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
459 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
460 -T $(UIMAGE_TYPE) \
461 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
462 -n $(UIMAGE_NAME) -d $< $@
463
464# XZ
465# ---------------------------------------------------------------------------
466# Use xzkern to compress the kernel image and xzmisc to compress other things.
467#
468# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
469# of the kernel decompressor. A BCJ filter is used if it is available for
470# the target architecture. xzkern also appends uncompressed size of the data
471# using size_append. The .xz format has the size information available at
472# the end of the file too, but it's in more complex format and it's good to
473# avoid changing the part of the boot code that reads the uncompressed size.
474# Note that the bytes added by size_append will make the xz tool think that
475# the file is corrupt. This is expected.
476#
477# xzmisc doesn't use size_append, so it can be used to create normal .xz
478# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
479# big dictionary would increase the memory usage too much in the multi-call
480# decompression mode. A BCJ filter isn't used either.
481quiet_cmd_xzkern = XZKERN $@
482 cmd_xzkern = cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh > $@
483
484quiet_cmd_xzkern_with_size = XZKERN $@
485 cmd_xzkern_with_size = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
486 $(size_append); } > $@
487
488quiet_cmd_xzmisc = XZMISC $@
489 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
490
491# ZSTD
492# ---------------------------------------------------------------------------
493# Appends the uncompressed size of the data using size_append. The .zst
494# format has the size information available at the beginning of the file too,
495# but it's in a more complex format and it's good to avoid changing the part
496# of the boot code that reads the uncompressed size.
497#
498# Note that the bytes added by size_append will make the zstd tool think that
499# the file is corrupt. This is expected.
500#
501# zstd uses a maximum window size of 8 MB. zstd22 uses a maximum window size of
502# 128 MB. zstd22 is used for kernel compression because it is decompressed in a
503# single pass, so zstd doesn't need to allocate a window buffer. When streaming
504# decompression is used, like initramfs decompression, zstd22 should likely not
505# be used because it would require zstd to allocate a 128 MB buffer.
506
507quiet_cmd_zstd = ZSTD $@
508 cmd_zstd = cat $(real-prereqs) | $(ZSTD) -19 > $@
509
510quiet_cmd_zstd22 = ZSTD22 $@
511 cmd_zstd22 = cat $(real-prereqs) | $(ZSTD) -22 --ultra > $@
512
513quiet_cmd_zstd22_with_size = ZSTD22 $@
514 cmd_zstd22_with_size = { cat $(real-prereqs) | $(ZSTD) -22 --ultra; $(size_append); } > $@
515
516# ASM offsets
517# ---------------------------------------------------------------------------
518
519# Default sed regexp - multiline due to syntax constraints
520#
521# Use [:space:] because LLVM's integrated assembler inserts <tab> around
522# the .ascii directive whereas GCC keeps the <space> as-is.
523define sed-offsets
524 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
525 /^->/{s:->#\(.*\):/* \1 */:; \
526 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
527 s:->::; p;}'
528endef
529
530# Use filechk to avoid rebuilds when a header changes, but the resulting file
531# does not
532define filechk_offsets
533 echo "#ifndef $2"; \
534 echo "#define $2"; \
535 echo "/*"; \
536 echo " * DO NOT MODIFY."; \
537 echo " *"; \
538 echo " * This file was generated by Kbuild"; \
539 echo " */"; \
540 echo ""; \
541 sed -ne $(sed-offsets) < $<; \
542 echo ""; \
543 echo "#endif"
544endef