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 += $(EXTRA_LDFLAGS)
7ifneq ($(always),)
8$(warning 'always' is deprecated. Please use 'always-y' instead)
9always-y += $(always)
10endif
11ifneq ($(hostprogs-y),)
12$(warning 'hostprogs-y' is deprecated. Please use 'hostprogs' instead)
13hostprogs += $(hostprogs-y)
14endif
15ifneq ($(hostprogs-m),)
16$(warning 'hostprogs-m' is deprecated. Please use 'hostprogs' instead)
17hostprogs += $(hostprogs-m)
18endif
19
20# flags that take effect in current and sub directories
21KBUILD_AFLAGS += $(subdir-asflags-y)
22KBUILD_CFLAGS += $(subdir-ccflags-y)
23
24# Figure out what we need to build from the various variables
25# ===========================================================================
26
27# When an object is listed to be built compiled-in and modular,
28# only build the compiled-in version
29obj-m := $(filter-out $(obj-y),$(obj-m))
30
31# Libraries are always collected in one lib file.
32# Filter out objects already built-in
33lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m)))
34
35# Subdirectories we need to descend into
36subdir-ym := $(sort $(subdir-y) $(subdir-m) \
37 $(patsubst %/,%, $(filter %/, $(obj-y) $(obj-m))))
38
39# Handle objects in subdirs:
40# - If we encounter foo/ in $(obj-y), replace it by foo/built-in.a and
41# foo/modules.order
42# - If we encounter foo/ in $(obj-m), replace it by foo/modules.order
43#
44# Generate modules.order to determine modorder. Unfortunately, we don't have
45# information about ordering between -y and -m subdirs. Just put -y's first.
46
47ifdef need-modorder
48obj-m := $(patsubst %/,%/modules.order, $(filter %/, $(obj-y)) $(obj-m))
49else
50obj-m := $(filter-out %/, $(obj-m))
51endif
52
53ifdef need-builtin
54obj-y := $(patsubst %/, %/built-in.a, $(obj-y))
55else
56obj-y := $(filter-out %/, $(obj-y))
57endif
58
59# If $(foo-objs), $(foo-y), $(foo-m), or $(foo-) exists, foo.o is a composite object
60multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))), $(m))))
61multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))), $(m))))
62multi-used := $(multi-used-y) $(multi-used-m)
63
64# Replace multi-part objects by their individual parts,
65# including built-in.a from subdirectories
66real-obj-y := $(foreach m, $(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m)))
67real-obj-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)) $($(m:.o=-))),$($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m)),$(m)))
68
69always-y += $(always-m)
70
71# DTB
72# If CONFIG_OF_ALL_DTBS is enabled, all DT blobs are built
73extra-y += $(dtb-y)
74extra-$(CONFIG_OF_ALL_DTBS) += $(dtb-)
75
76ifneq ($(CHECK_DTBS),)
77extra-y += $(patsubst %.dtb,%.dt.yaml, $(dtb-y))
78extra-$(CONFIG_OF_ALL_DTBS) += $(patsubst %.dtb,%.dt.yaml, $(dtb-))
79endif
80
81# Add subdir path
82
83extra-y := $(addprefix $(obj)/,$(extra-y))
84always-y := $(addprefix $(obj)/,$(always-y))
85targets := $(addprefix $(obj)/,$(targets))
86obj-m := $(addprefix $(obj)/,$(obj-m))
87lib-y := $(addprefix $(obj)/,$(lib-y))
88real-obj-y := $(addprefix $(obj)/,$(real-obj-y))
89real-obj-m := $(addprefix $(obj)/,$(real-obj-m))
90multi-used-m := $(addprefix $(obj)/,$(multi-used-m))
91subdir-ym := $(addprefix $(obj)/,$(subdir-ym))
92
93# Finds the multi-part object the current object will be linked into.
94# If the object belongs to two or more multi-part objects, list them all.
95modname-multi = $(sort $(foreach m,$(multi-used),\
96 $(if $(filter $*.o, $($(m:.o=-objs)) $($(m:.o=-y)) $($(m:.o=-m))),$(m:.o=))))
97
98__modname = $(if $(modname-multi),$(modname-multi),$(basetarget))
99
100modname = $(subst $(space),:,$(__modname))
101modfile = $(addprefix $(obj)/,$(__modname))
102
103# target with $(obj)/ and its suffix stripped
104target-stem = $(basename $(patsubst $(obj)/%,%,$@))
105
106# These flags are needed for modversions and compiling, so we define them here
107# $(modname_flags) defines KBUILD_MODNAME as the name of the module it will
108# end up in (or would, if it gets compiled in)
109name-fix = $(call stringify,$(subst $(comma),_,$(subst -,_,$1)))
110basename_flags = -DKBUILD_BASENAME=$(call name-fix,$(basetarget))
111modname_flags = -DKBUILD_MODNAME=$(call name-fix,$(modname))
112modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
113
114orig_c_flags = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) \
115 $(ccflags-y) $(CFLAGS_$(target-stem).o)
116_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), $(orig_c_flags))
117orig_a_flags = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) \
118 $(asflags-y) $(AFLAGS_$(target-stem).o)
119_a_flags = $(filter-out $(AFLAGS_REMOVE_$(target-stem).o), $(orig_a_flags))
120_cpp_flags = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(target-stem).lds)
121
122#
123# Enable gcov profiling flags for a file, directory or for all files depending
124# on variables GCOV_PROFILE_obj.o, GCOV_PROFILE and CONFIG_GCOV_PROFILE_ALL
125# (in this order)
126#
127ifeq ($(CONFIG_GCOV_KERNEL),y)
128_c_flags += $(if $(patsubst n%,, \
129 $(GCOV_PROFILE_$(basetarget).o)$(GCOV_PROFILE)$(CONFIG_GCOV_PROFILE_ALL)), \
130 $(CFLAGS_GCOV))
131endif
132
133#
134# Enable address sanitizer flags for kernel except some files or directories
135# we don't want to check (depends on variables KASAN_SANITIZE_obj.o, KASAN_SANITIZE)
136#
137ifeq ($(CONFIG_KASAN),y)
138_c_flags += $(if $(patsubst n%,, \
139 $(KASAN_SANITIZE_$(basetarget).o)$(KASAN_SANITIZE)y), \
140 $(CFLAGS_KASAN), $(CFLAGS_KASAN_NOSANITIZE))
141endif
142
143ifeq ($(CONFIG_UBSAN),y)
144_c_flags += $(if $(patsubst n%,, \
145 $(UBSAN_SANITIZE_$(basetarget).o)$(UBSAN_SANITIZE)$(CONFIG_UBSAN_SANITIZE_ALL)), \
146 $(CFLAGS_UBSAN))
147endif
148
149ifeq ($(CONFIG_KCOV),y)
150_c_flags += $(if $(patsubst n%,, \
151 $(KCOV_INSTRUMENT_$(basetarget).o)$(KCOV_INSTRUMENT)$(CONFIG_KCOV_INSTRUMENT_ALL)), \
152 $(CFLAGS_KCOV))
153endif
154
155#
156# Enable KCSAN flags except some files or directories we don't want to check
157# (depends on variables KCSAN_SANITIZE_obj.o, KCSAN_SANITIZE)
158#
159ifeq ($(CONFIG_KCSAN),y)
160_c_flags += $(if $(patsubst n%,, \
161 $(KCSAN_SANITIZE_$(basetarget).o)$(KCSAN_SANITIZE)y), \
162 $(CFLAGS_KCSAN))
163endif
164
165# $(srctree)/$(src) for including checkin headers from generated source files
166# $(objtree)/$(obj) for including generated headers from checkin source files
167ifeq ($(KBUILD_EXTMOD),)
168ifdef building_out_of_srctree
169_c_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
170_a_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
171_cpp_flags += -I $(srctree)/$(src) -I $(objtree)/$(obj)
172endif
173endif
174
175part-of-module = $(if $(filter $(basename $@).o, $(real-obj-m)),y)
176quiet_modtag = $(if $(part-of-module),[M], )
177
178modkern_cflags = \
179 $(if $(part-of-module), \
180 $(KBUILD_CFLAGS_MODULE) $(CFLAGS_MODULE), \
181 $(KBUILD_CFLAGS_KERNEL) $(CFLAGS_KERNEL) $(modfile_flags))
182
183modkern_aflags = $(if $(part-of-module), \
184 $(KBUILD_AFLAGS_MODULE) $(AFLAGS_MODULE), \
185 $(KBUILD_AFLAGS_KERNEL) $(AFLAGS_KERNEL))
186
187c_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
188 -include $(srctree)/include/linux/compiler_types.h \
189 $(_c_flags) $(modkern_cflags) \
190 $(basename_flags) $(modname_flags)
191
192a_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
193 $(_a_flags) $(modkern_aflags)
194
195cpp_flags = -Wp,-MMD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) \
196 $(_cpp_flags)
197
198ld_flags = $(KBUILD_LDFLAGS) $(ldflags-y) $(LDFLAGS_$(@F))
199
200DTC_INCLUDE := $(srctree)/scripts/dtc/include-prefixes
201
202dtc_cpp_flags = -Wp,-MMD,$(depfile).pre.tmp -nostdinc \
203 $(addprefix -I,$(DTC_INCLUDE)) \
204 -undef -D__DTS__
205
206# Useful for describing the dependency of composite objects
207# Usage:
208# $(call multi_depend, multi_used_targets, suffix_to_remove, suffix_to_add)
209define multi_depend
210$(foreach m, $(notdir $1), \
211 $(eval $(obj)/$m: \
212 $(addprefix $(obj)/, $(foreach s, $3, $($(m:%$(strip $2)=%$(s)))))))
213endef
214
215# Shipped files
216# ===========================================================================
217
218quiet_cmd_shipped = SHIPPED $@
219cmd_shipped = cat $< > $@
220
221$(obj)/%: $(src)/%_shipped
222 $(call cmd,shipped)
223
224# Commands useful for building a boot image
225# ===========================================================================
226#
227# Use as following:
228#
229# target: source(s) FORCE
230# $(if_changed,ld/objcopy/gzip)
231#
232# and add target to extra-y so that we know we have to
233# read in the saved command line
234
235# Linking
236# ---------------------------------------------------------------------------
237
238quiet_cmd_ld = LD $@
239 cmd_ld = $(LD) $(ld_flags) $(real-prereqs) -o $@
240
241# Archive
242# ---------------------------------------------------------------------------
243
244quiet_cmd_ar = AR $@
245 cmd_ar = rm -f $@; $(AR) cDPrsT $@ $(real-prereqs)
246
247# Objcopy
248# ---------------------------------------------------------------------------
249
250quiet_cmd_objcopy = OBJCOPY $@
251cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@
252
253# Gzip
254# ---------------------------------------------------------------------------
255
256quiet_cmd_gzip = GZIP $@
257 cmd_gzip = cat $(real-prereqs) | $(KGZIP) -n -f -9 > $@
258
259# DTC
260# ---------------------------------------------------------------------------
261DTC ?= $(objtree)/scripts/dtc/dtc
262
263# Disable noisy checks by default
264ifeq ($(findstring 1,$(KBUILD_EXTRA_WARN)),)
265DTC_FLAGS += -Wno-unit_address_vs_reg \
266 -Wno-unit_address_format \
267 -Wno-avoid_unnecessary_addr_size \
268 -Wno-alias_paths \
269 -Wno-graph_child_address \
270 -Wno-simple_bus_reg \
271 -Wno-unique_unit_address \
272 -Wno-pci_device_reg
273endif
274
275ifneq ($(findstring 2,$(KBUILD_EXTRA_WARN)),)
276DTC_FLAGS += -Wnode_name_chars_strict \
277 -Wproperty_name_chars_strict
278endif
279
280DTC_FLAGS += $(DTC_FLAGS_$(basetarget))
281
282# Generate an assembly file to wrap the output of the device tree compiler
283quiet_cmd_dt_S_dtb= DTB $@
284cmd_dt_S_dtb= \
285{ \
286 echo '\#include <asm-generic/vmlinux.lds.h>'; \
287 echo '.section .dtb.init.rodata,"a"'; \
288 echo '.balign STRUCT_ALIGNMENT'; \
289 echo '.global __dtb_$(subst -,_,$(*F))_begin'; \
290 echo '__dtb_$(subst -,_,$(*F))_begin:'; \
291 echo '.incbin "$<" '; \
292 echo '__dtb_$(subst -,_,$(*F))_end:'; \
293 echo '.global __dtb_$(subst -,_,$(*F))_end'; \
294 echo '.balign STRUCT_ALIGNMENT'; \
295} > $@
296
297$(obj)/%.dtb.S: $(obj)/%.dtb FORCE
298 $(call if_changed,dt_S_dtb)
299
300quiet_cmd_dtc = DTC $@
301cmd_dtc = mkdir -p $(dir ${dtc-tmp}) ; \
302 $(HOSTCC) -E $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
303 $(DTC) -O $(patsubst .%,%,$(suffix $@)) -o $@ -b 0 \
304 $(addprefix -i,$(dir $<) $(DTC_INCLUDE)) $(DTC_FLAGS) \
305 -d $(depfile).dtc.tmp $(dtc-tmp) ; \
306 cat $(depfile).pre.tmp $(depfile).dtc.tmp > $(depfile)
307
308$(obj)/%.dtb: $(src)/%.dts $(DTC) FORCE
309 $(call if_changed_dep,dtc)
310
311DT_CHECKER ?= dt-validate
312DT_BINDING_DIR := Documentation/devicetree/bindings
313# DT_TMP_SCHEMA may be overridden from Documentation/devicetree/bindings/Makefile
314DT_TMP_SCHEMA ?= $(objtree)/$(DT_BINDING_DIR)/processed-schema.yaml
315
316quiet_cmd_dtb_check = CHECK $@
317 cmd_dtb_check = $(DT_CHECKER) -u $(srctree)/$(DT_BINDING_DIR) -p $(DT_TMP_SCHEMA) $@
318
319define rule_dtc
320 $(call cmd_and_fixdep,dtc)
321 $(call cmd,dtb_check)
322endef
323
324$(obj)/%.dt.yaml: $(src)/%.dts $(DTC) $(DT_TMP_SCHEMA) FORCE
325 $(call if_changed_rule,dtc,yaml)
326
327dtc-tmp = $(subst $(comma),_,$(dot-target).dts.tmp)
328
329# Bzip2
330# ---------------------------------------------------------------------------
331
332# Bzip2 and LZMA do not include size in file... so we have to fake that;
333# append the size as a 32-bit littleendian number as gzip does.
334size_append = printf $(shell \
335dec_size=0; \
336for F in $(real-prereqs); do \
337 fsize=$$($(CONFIG_SHELL) $(srctree)/scripts/file-size.sh $$F); \
338 dec_size=$$(expr $$dec_size + $$fsize); \
339done; \
340printf "%08x\n" $$dec_size | \
341 sed 's/\(..\)/\1 /g' | { \
342 read ch0 ch1 ch2 ch3; \
343 for ch in $$ch3 $$ch2 $$ch1 $$ch0; do \
344 printf '%s%03o' '\\' $$((0x$$ch)); \
345 done; \
346 } \
347)
348
349quiet_cmd_bzip2 = BZIP2 $@
350 cmd_bzip2 = { cat $(real-prereqs) | $(KBZIP2) -9; $(size_append); } > $@
351
352# Lzma
353# ---------------------------------------------------------------------------
354
355quiet_cmd_lzma = LZMA $@
356 cmd_lzma = { cat $(real-prereqs) | $(LZMA) -9; $(size_append); } > $@
357
358quiet_cmd_lzo = LZO $@
359 cmd_lzo = { cat $(real-prereqs) | $(KLZOP) -9; $(size_append); } > $@
360
361quiet_cmd_lz4 = LZ4 $@
362 cmd_lz4 = { cat $(real-prereqs) | $(LZ4) -l -c1 stdin stdout; \
363 $(size_append); } > $@
364
365# U-Boot mkimage
366# ---------------------------------------------------------------------------
367
368MKIMAGE := $(srctree)/scripts/mkuboot.sh
369
370# SRCARCH just happens to match slightly more than ARCH (on sparc), so reduces
371# the number of overrides in arch makefiles
372UIMAGE_ARCH ?= $(SRCARCH)
373UIMAGE_COMPRESSION ?= $(if $(2),$(2),none)
374UIMAGE_OPTS-y ?=
375UIMAGE_TYPE ?= kernel
376UIMAGE_LOADADDR ?= arch_must_set_this
377UIMAGE_ENTRYADDR ?= $(UIMAGE_LOADADDR)
378UIMAGE_NAME ?= 'Linux-$(KERNELRELEASE)'
379
380quiet_cmd_uimage = UIMAGE $@
381 cmd_uimage = $(BASH) $(MKIMAGE) -A $(UIMAGE_ARCH) -O linux \
382 -C $(UIMAGE_COMPRESSION) $(UIMAGE_OPTS-y) \
383 -T $(UIMAGE_TYPE) \
384 -a $(UIMAGE_LOADADDR) -e $(UIMAGE_ENTRYADDR) \
385 -n $(UIMAGE_NAME) -d $< $@
386
387# XZ
388# ---------------------------------------------------------------------------
389# Use xzkern to compress the kernel image and xzmisc to compress other things.
390#
391# xzkern uses a big LZMA2 dictionary since it doesn't increase memory usage
392# of the kernel decompressor. A BCJ filter is used if it is available for
393# the target architecture. xzkern also appends uncompressed size of the data
394# using size_append. The .xz format has the size information available at
395# the end of the file too, but it's in more complex format and it's good to
396# avoid changing the part of the boot code that reads the uncompressed size.
397# Note that the bytes added by size_append will make the xz tool think that
398# the file is corrupt. This is expected.
399#
400# xzmisc doesn't use size_append, so it can be used to create normal .xz
401# files. xzmisc uses smaller LZMA2 dictionary than xzkern, because a very
402# big dictionary would increase the memory usage too much in the multi-call
403# decompression mode. A BCJ filter isn't used either.
404quiet_cmd_xzkern = XZKERN $@
405 cmd_xzkern = { cat $(real-prereqs) | sh $(srctree)/scripts/xz_wrap.sh; \
406 $(size_append); } > $@
407
408quiet_cmd_xzmisc = XZMISC $@
409 cmd_xzmisc = cat $(real-prereqs) | $(XZ) --check=crc32 --lzma2=dict=1MiB > $@
410
411# ASM offsets
412# ---------------------------------------------------------------------------
413
414# Default sed regexp - multiline due to syntax constraints
415#
416# Use [:space:] because LLVM's integrated assembler inserts <tab> around
417# the .ascii directive whereas GCC keeps the <space> as-is.
418define sed-offsets
419 's:^[[:space:]]*\.ascii[[:space:]]*"\(.*\)".*:\1:; \
420 /^->/{s:->#\(.*\):/* \1 */:; \
421 s:^->\([^ ]*\) [\$$#]*\([^ ]*\) \(.*\):#define \1 \2 /* \3 */:; \
422 s:->::; p;}'
423endef
424
425# Use filechk to avoid rebuilds when a header changes, but the resulting file
426# does not
427define filechk_offsets
428 echo "#ifndef $2"; \
429 echo "#define $2"; \
430 echo "/*"; \
431 echo " * DO NOT MODIFY."; \
432 echo " *"; \
433 echo " * This file was generated by Kbuild"; \
434 echo " */"; \
435 echo ""; \
436 sed -ne $(sed-offsets) < $<; \
437 echo ""; \
438 echo "#endif"
439endef