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Linus Torvalds1da177e2005-04-16 15:20:36 -07001# ==========================================================================
2# Building
3# ==========================================================================
4
5src := $(obj)
6
7.PHONY: __build
8__build:
9
10# Read .config if it exist, otherwise ignore
11-include .config
12
Sam Ravnborg2a691472005-07-25 20:26:04 +000013# The filename Kbuild has precedence over Makefile
Sam Ravnborgdb8c1a72005-07-27 22:11:01 +020014kbuild-dir := $(if $(filter /%,$(src)),$(src),$(srctree)/$(src))
15include $(if $(wildcard $(kbuild-dir)/Kbuild), $(kbuild-dir)/Kbuild, $(kbuild-dir)/Makefile)
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
Sam Ravnborg8ec4b4f2005-07-25 20:10:36 +000017include scripts/Kbuild.include
Linus Torvalds1da177e2005-04-16 15:20:36 -070018include scripts/Makefile.lib
19
20ifdef host-progs
21ifneq ($(hostprogs-y),$(host-progs))
22$(warning kbuild: $(obj)/Makefile - Usage of host-progs is deprecated. Please replace with hostprogs-y!)
23hostprogs-y += $(host-progs)
24endif
25endif
26
27# Do not include host rules unles needed
28ifneq ($(hostprogs-y)$(hostprogs-m),)
29include scripts/Makefile.host
30endif
31
32ifneq ($(KBUILD_SRC),)
33# Create output directory if not already present
34_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
35
36# Create directories for object files if directory does not exist
37# Needed when obj-y := dir/file.o syntax is used
38_dummy := $(foreach d,$(obj-dirs), $(shell [ -d $(d) ] || mkdir -p $(d)))
39endif
40
41
42ifdef EXTRA_TARGETS
43$(warning kbuild: $(obj)/Makefile - Usage of EXTRA_TARGETS is obsolete in 2.6. Please fix!)
44endif
45
46ifdef build-targets
47$(warning kbuild: $(obj)/Makefile - Usage of build-targets is obsolete in 2.6. Please fix!)
48endif
49
50ifdef export-objs
51$(warning kbuild: $(obj)/Makefile - Usage of export-objs is obsolete in 2.6. Please fix!)
52endif
53
54ifdef O_TARGET
55$(warning kbuild: $(obj)/Makefile - Usage of O_TARGET := $(O_TARGET) is obsolete in 2.6. Please fix!)
56endif
57
58ifdef L_TARGET
59$(error kbuild: $(obj)/Makefile - Use of L_TARGET is replaced by lib-y in 2.6. Please fix!)
60endif
61
62ifdef list-multi
63$(warning kbuild: $(obj)/Makefile - list-multi := $(list-multi) is obsolete in 2.6. Please fix!)
64endif
65
66ifndef obj
67$(warning kbuild: Makefile.build is included improperly)
68endif
69
70# ===========================================================================
71
72ifneq ($(strip $(lib-y) $(lib-m) $(lib-n) $(lib-)),)
73lib-target := $(obj)/lib.a
74endif
75
76ifneq ($(strip $(obj-y) $(obj-m) $(obj-n) $(obj-) $(lib-target)),)
77builtin-target := $(obj)/built-in.o
78endif
79
80# We keep a list of all modules in $(MODVERDIR)
81
82__build: $(if $(KBUILD_BUILTIN),$(builtin-target) $(lib-target) $(extra-y)) \
83 $(if $(KBUILD_MODULES),$(obj-m)) \
84 $(subdir-ym) $(always)
85 @:
86
87# Linus' kernel sanity checking tool
88ifneq ($(KBUILD_CHECKSRC),0)
89 ifeq ($(KBUILD_CHECKSRC),2)
90 quiet_cmd_force_checksrc = CHECK $<
91 cmd_force_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
92 else
93 quiet_cmd_checksrc = CHECK $<
94 cmd_checksrc = $(CHECK) $(CHECKFLAGS) $(c_flags) $< ;
95 endif
96endif
97
98
99# Compile C sources (.c)
100# ---------------------------------------------------------------------------
101
102# Default is built-in, unless we know otherwise
103modkern_cflags := $(CFLAGS_KERNEL)
104quiet_modtag := $(empty) $(empty)
105
106$(real-objs-m) : modkern_cflags := $(CFLAGS_MODULE)
107$(real-objs-m:.o=.i) : modkern_cflags := $(CFLAGS_MODULE)
108$(real-objs-m:.o=.s) : modkern_cflags := $(CFLAGS_MODULE)
109$(real-objs-m:.o=.lst): modkern_cflags := $(CFLAGS_MODULE)
110
111$(real-objs-m) : quiet_modtag := [M]
112$(real-objs-m:.o=.i) : quiet_modtag := [M]
113$(real-objs-m:.o=.s) : quiet_modtag := [M]
114$(real-objs-m:.o=.lst): quiet_modtag := [M]
115
116$(obj-m) : quiet_modtag := [M]
117
118# Default for not multi-part modules
119modname = $(*F)
120
121$(multi-objs-m) : modname = $(modname-multi)
122$(multi-objs-m:.o=.i) : modname = $(modname-multi)
123$(multi-objs-m:.o=.s) : modname = $(modname-multi)
124$(multi-objs-m:.o=.lst) : modname = $(modname-multi)
125$(multi-objs-y) : modname = $(modname-multi)
126$(multi-objs-y:.o=.i) : modname = $(modname-multi)
127$(multi-objs-y:.o=.s) : modname = $(modname-multi)
128$(multi-objs-y:.o=.lst) : modname = $(modname-multi)
129
130quiet_cmd_cc_s_c = CC $(quiet_modtag) $@
131cmd_cc_s_c = $(CC) $(c_flags) -S -o $@ $<
132
133%.s: %.c FORCE
134 $(call if_changed_dep,cc_s_c)
135
136quiet_cmd_cc_i_c = CPP $(quiet_modtag) $@
137cmd_cc_i_c = $(CPP) $(c_flags) -o $@ $<
138
139%.i: %.c FORCE
140 $(call if_changed_dep,cc_i_c)
141
142# C (.c) files
143# The C file is compiled and updated dependency information is generated.
144# (See cmd_cc_o_c + relevant part of rule_cc_o_c)
145
146quiet_cmd_cc_o_c = CC $(quiet_modtag) $@
147
148ifndef CONFIG_MODVERSIONS
149cmd_cc_o_c = $(CC) $(c_flags) -c -o $@ $<
150
151else
152# When module versioning is enabled the following steps are executed:
153# o compile a .tmp_<file>.o from <file>.c
154# o if .tmp_<file>.o doesn't contain a __ksymtab version, i.e. does
155# not export symbols, we just rename .tmp_<file>.o to <file>.o and
156# are done.
157# o otherwise, we calculate symbol versions using the good old
158# genksyms on the preprocessed source and postprocess them in a way
159# that they are usable as a linker script
160# o generate <file>.o from .tmp_<file>.o using the linker to
161# replace the unresolved symbols __crc_exported_symbol with
162# the actual value of the checksum generated by genksyms
163
164cmd_cc_o_c = $(CC) $(c_flags) -c -o $(@D)/.tmp_$(@F) $<
165cmd_modversions = \
166 if $(OBJDUMP) -h $(@D)/.tmp_$(@F) | grep -q __ksymtab; then \
167 $(CPP) -D__GENKSYMS__ $(c_flags) $< \
168 | $(GENKSYMS) \
169 > $(@D)/.tmp_$(@F:.o=.ver); \
170 \
171 $(LD) $(LDFLAGS) -r -o $@ $(@D)/.tmp_$(@F) \
172 -T $(@D)/.tmp_$(@F:.o=.ver); \
173 rm -f $(@D)/.tmp_$(@F) $(@D)/.tmp_$(@F:.o=.ver); \
174 else \
Sam Ravnborgcfca82f2005-07-14 20:12:40 +0000175 mv -f $(@D)/.tmp_$(@F) $@; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 fi;
177endif
178
179define rule_cc_o_c
180 $(if $($(quiet)cmd_checksrc),echo ' $($(quiet)cmd_checksrc)';) \
181 $(cmd_checksrc) \
Jan Beulich84769942005-06-23 00:10:00 -0700182 $(if $($(quiet)cmd_cc_o_c),echo ' $(subst ','\'',$($(quiet)cmd_cc_o_c))';) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 $(cmd_cc_o_c); \
184 $(cmd_modversions) \
Jan Beulich84769942005-06-23 00:10:00 -0700185 scripts/basic/fixdep $(depfile) $@ '$(subst ','\'',$(cmd_cc_o_c))' > $(@D)/.$(@F).tmp; \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 rm -f $(depfile); \
187 mv -f $(@D)/.$(@F).tmp $(@D)/.$(@F).cmd
188endef
189
190# Built-in and composite module parts
191
192%.o: %.c FORCE
193 $(call cmd,force_checksrc)
194 $(call if_changed_rule,cc_o_c)
195
196# Single-part modules are special since we need to mark them in $(MODVERDIR)
197
198$(single-used-m): %.o: %.c FORCE
199 $(call cmd,force_checksrc)
200 $(call if_changed_rule,cc_o_c)
201 @{ echo $(@:.o=.ko); echo $@; } > $(MODVERDIR)/$(@F:.o=.mod)
202
203quiet_cmd_cc_lst_c = MKLST $@
204 cmd_cc_lst_c = $(CC) $(c_flags) -g -c -o $*.o $< && \
205 $(CONFIG_SHELL) $(srctree)/scripts/makelst $*.o \
206 System.map $(OBJDUMP) > $@
207
208%.lst: %.c FORCE
209 $(call if_changed_dep,cc_lst_c)
210
211# Compile assembler sources (.S)
212# ---------------------------------------------------------------------------
213
214modkern_aflags := $(AFLAGS_KERNEL)
215
216$(real-objs-m) : modkern_aflags := $(AFLAGS_MODULE)
217$(real-objs-m:.o=.s): modkern_aflags := $(AFLAGS_MODULE)
218
219quiet_cmd_as_s_S = CPP $(quiet_modtag) $@
220cmd_as_s_S = $(CPP) $(a_flags) -o $@ $<
221
222%.s: %.S FORCE
223 $(call if_changed_dep,as_s_S)
224
225quiet_cmd_as_o_S = AS $(quiet_modtag) $@
226cmd_as_o_S = $(CC) $(a_flags) -c -o $@ $<
227
228%.o: %.S FORCE
229 $(call if_changed_dep,as_o_S)
230
231targets += $(real-objs-y) $(real-objs-m) $(lib-y)
232targets += $(extra-y) $(MAKECMDGOALS) $(always)
233
234# Linker scripts preprocessor (.lds.S -> .lds)
235# ---------------------------------------------------------------------------
236quiet_cmd_cpp_lds_S = LDS $@
237 cmd_cpp_lds_S = $(CPP) $(cpp_flags) -D__ASSEMBLY__ -o $@ $<
238
239%.lds: %.lds.S FORCE
240 $(call if_changed_dep,cpp_lds_S)
241
242# Build the compiled-in targets
243# ---------------------------------------------------------------------------
244
245# To build objects in subdirs, we need to descend into the directories
246$(sort $(subdir-obj-y)): $(subdir-ym) ;
247
248#
249# Rule to compile a set of .o files into one .o file
250#
251ifdef builtin-target
252quiet_cmd_link_o_target = LD $@
253# If the list of objects to link is empty, just create an empty built-in.o
254cmd_link_o_target = $(if $(strip $(obj-y)),\
255 $(LD) $(ld_flags) -r -o $@ $(filter $(obj-y), $^),\
256 rm -f $@; $(AR) rcs $@)
257
258$(builtin-target): $(obj-y) FORCE
259 $(call if_changed,link_o_target)
260
261targets += $(builtin-target)
262endif # builtin-target
263
264#
265# Rule to compile a set of .o files into one .a file
266#
267ifdef lib-target
268quiet_cmd_link_l_target = AR $@
269cmd_link_l_target = rm -f $@; $(AR) $(EXTRA_ARFLAGS) rcs $@ $(lib-y)
270
271$(lib-target): $(lib-y) FORCE
272 $(call if_changed,link_l_target)
273
274targets += $(lib-target)
275endif
276
277#
278# Rule to link composite objects
279#
280# Composite objects are specified in kbuild makefile as follows:
281# <composite-object>-objs := <list of .o files>
282# or
283# <composite-object>-y := <list of .o files>
284link_multi_deps = \
285$(filter $(addprefix $(obj)/, \
286$($(subst $(obj)/,,$(@:.o=-objs))) \
287$($(subst $(obj)/,,$(@:.o=-y)))), $^)
288
289quiet_cmd_link_multi-y = LD $@
290cmd_link_multi-y = $(LD) $(ld_flags) -r -o $@ $(link_multi_deps)
291
292quiet_cmd_link_multi-m = LD [M] $@
293cmd_link_multi-m = $(LD) $(ld_flags) $(LDFLAGS_MODULE) -o $@ $(link_multi_deps)
294
295# We would rather have a list of rules like
296# foo.o: $(foo-objs)
297# but that's not so easy, so we rather make all composite objects depend
298# on the set of all their parts
299$(multi-used-y) : %.o: $(multi-objs-y) FORCE
300 $(call if_changed,link_multi-y)
301
302$(multi-used-m) : %.o: $(multi-objs-m) FORCE
303 $(call if_changed,link_multi-m)
304 @{ echo $(@:.o=.ko); echo $(link_multi_deps); } > $(MODVERDIR)/$(@F:.o=.mod)
305
306targets += $(multi-used-y) $(multi-used-m)
307
308
309# Descending
310# ---------------------------------------------------------------------------
311
312.PHONY: $(subdir-ym)
313$(subdir-ym):
314 $(Q)$(MAKE) $(build)=$@
315
316# Add FORCE to the prequisites of a target to force it to be always rebuilt.
317# ---------------------------------------------------------------------------
318
319.PHONY: FORCE
320
321FORCE:
322
323# Read all saved command lines and dependencies for the $(targets) we
324# may be building above, using $(if_changed{,_dep}). As an
325# optimization, we don't need to read them if the target does not
326# exist, we will rebuild anyway in that case.
327
328targets := $(wildcard $(sort $(targets)))
329cmd_files := $(wildcard $(foreach f,$(targets),$(dir $(f)).$(notdir $(f)).cmd))
330
331ifneq ($(cmd_files),)
332 include $(cmd_files)
333endif