1# Figure out what we need to build from the various variables 2# =========================================================================== 3 4# When an object is listed to be built compiled-in and modular, 5# only build the compiled-in version 6 7obj-m := $(filter-out $(obj-y),$(obj-m)) 8 9# Libraries are always collected in one lib file. 10# Filter out objects already built-in 11 12lib-y := $(filter-out $(obj-y), $(sort $(lib-y) $(lib-m))) 13 14 15# Handle objects in subdirs 16# --------------------------------------------------------------------------- 17# o if we encounter foo/ in $(obj-y), replace it by foo/built-in.o 18# and add the directory to the list of dirs to descend into: $(subdir-y) 19# o if we encounter foo/ in $(obj-m), remove it from $(obj-m) 20# and add the directory to the list of dirs to descend into: $(subdir-m) 21 22__subdir-y := $(patsubst %/,%,$(filter %/, $(obj-y))) 23subdir-y += $(__subdir-y) 24__subdir-m := $(patsubst %/,%,$(filter %/, $(obj-m))) 25subdir-m += $(__subdir-m) 26obj-y := $(patsubst %/, %/built-in.o, $(obj-y)) 27obj-m := $(filter-out %/, $(obj-m)) 28 29# Subdirectories we need to descend into 30 31subdir-ym := $(sort $(subdir-y) $(subdir-m)) 32 33# if $(foo-objs) exists, foo.o is a composite object 34multi-used-y := $(sort $(foreach m,$(obj-y), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m)))) 35multi-used-m := $(sort $(foreach m,$(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))), $(m)))) 36multi-used := $(multi-used-y) $(multi-used-m) 37single-used-m := $(sort $(filter-out $(multi-used-m),$(obj-m))) 38 39# Build list of the parts of our composite objects, our composite 40# objects depend on those (obviously) 41multi-objs-y := $(foreach m, $(multi-used-y), $($(m:.o=-objs)) $($(m:.o=-y))) 42multi-objs-m := $(foreach m, $(multi-used-m), $($(m:.o=-objs)) $($(m:.o=-y))) 43multi-objs := $(multi-objs-y) $(multi-objs-m) 44 45# $(subdir-obj-y) is the list of objects in $(obj-y) which uses dir/ to 46# tell kbuild to descend 47subdir-obj-y := $(filter %/built-in.o, $(obj-y)) 48 49# $(obj-dirs) is a list of directories that contain object files 50obj-dirs := $(dir $(multi-objs) $(subdir-obj-y)) 51 52# Replace multi-part objects by their individual parts, look at local dir only 53real-objs-y := $(foreach m, $(filter-out $(subdir-obj-y), $(obj-y)), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) $(extra-y) 54real-objs-m := $(foreach m, $(obj-m), $(if $(strip $($(m:.o=-objs)) $($(m:.o=-y))),$($(m:.o=-objs)) $($(m:.o=-y)),$(m))) 55 56# Add subdir path 57 58extra-y := $(addprefix $(obj)/,$(extra-y)) 59always := $(addprefix $(obj)/,$(always)) 60targets := $(addprefix $(obj)/,$(targets)) 61obj-y := $(addprefix $(obj)/,$(obj-y)) 62obj-m := $(addprefix $(obj)/,$(obj-m)) 63lib-y := $(addprefix $(obj)/,$(lib-y)) 64subdir-obj-y := $(addprefix $(obj)/,$(subdir-obj-y)) 65real-objs-y := $(addprefix $(obj)/,$(real-objs-y)) 66real-objs-m := $(addprefix $(obj)/,$(real-objs-m)) 67single-used-m := $(addprefix $(obj)/,$(single-used-m)) 68multi-used-y := $(addprefix $(obj)/,$(multi-used-y)) 69multi-used-m := $(addprefix $(obj)/,$(multi-used-m)) 70multi-objs-y := $(addprefix $(obj)/,$(multi-objs-y)) 71multi-objs-m := $(addprefix $(obj)/,$(multi-objs-m)) 72subdir-ym := $(addprefix $(obj)/,$(subdir-ym)) 73obj-dirs := $(addprefix $(obj)/,$(obj-dirs)) 74 75# These flags are needed for modversions and compiling, so we define them here 76# already 77# $(modname_flags) #defines KBUILD_MODNAME as the name of the module it will 78# end up in (or would, if it gets compiled in) 79# Note: It's possible that one object gets potentially linked into more 80# than one module. In that case KBUILD_MODNAME will be set to foo_bar, 81# where foo and bar are the name of the modules. 82name-fix = $(subst $(comma),_,$(subst -,_,$1)) 83basename_flags = -D"KBUILD_BASENAME=KBUILD_STR($(call name-fix,$(basetarget)))" 84modname_flags = $(if $(filter 1,$(words $(modname))),\ 85 -D"KBUILD_MODNAME=KBUILD_STR($(call name-fix,$(modname)))") 86 87_c_flags = $(KBUILD_CFLAGS) $(EXTRA_CFLAGS) $(CFLAGS_$(basetarget).o) 88_a_flags = $(AFLAGS) $(EXTRA_AFLAGS) $(AFLAGS_$(basetarget).o) 89_cpp_flags = $(CPPFLAGS) $(EXTRA_CPPFLAGS) $(CPPFLAGS_$(@F)) 90 91# If building the kernel in a separate objtree expand all occurrences 92# of -Idir to -I$(srctree)/dir except for absolute paths (starting with '/'). 93 94ifeq ($(KBUILD_SRC),) 95__c_flags = $(_c_flags) 96__a_flags = $(_a_flags) 97__cpp_flags = $(_cpp_flags) 98else 99 100# -I$(obj) locates generated .h files 101# $(call addtree,-I$(obj)) locates .h files in srctree, from generated .c files 102# and locates generated .h files 103# FIXME: Replace both with specific CFLAGS* statements in the makefiles 104__c_flags = $(call addtree,-I$(obj)) $(call flags,_c_flags) 105__a_flags = $(call flags,_a_flags) 106__cpp_flags = $(call flags,_cpp_flags) 107endif 108 109c_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(CPPFLAGS) \ 110 $(__c_flags) $(modkern_cflags) \ 111 -D"KBUILD_STR(s)=\#s" $(basename_flags) $(modname_flags) 112 113a_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(CPPFLAGS) \ 114 $(__a_flags) $(modkern_aflags) 115 116cpp_flags = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(__cpp_flags) 117 118ld_flags = $(LDFLAGS) $(EXTRA_LDFLAGS) 119 120# Finds the multi-part object the current object will be linked into 121modname-multi = $(sort $(foreach m,$(multi-used),\ 122 $(if $(filter $(subst $(obj)/,,$*.o), $($(m:.o=-objs)) $($(m:.o=-y))),$(m:.o=)))) 123 124# Shipped files 125# =========================================================================== 126 127quiet_cmd_shipped = SHIPPED $@ 128cmd_shipped = cat $< > $@ 129 130$(obj)/%:: $(src)/%_shipped 131 $(call cmd,shipped) 132 133# Commands useful for building a boot image 134# =========================================================================== 135# 136# Use as following: 137# 138# target: source(s) FORCE 139# $(if_changed,ld/objcopy/gzip) 140# 141# and add target to extra-y so that we know we have to 142# read in the saved command line 143 144# Linking 145# --------------------------------------------------------------------------- 146 147quiet_cmd_ld = LD $@ 148cmd_ld = $(LD) $(LDFLAGS) $(EXTRA_LDFLAGS) $(LDFLAGS_$(@F)) \ 149 $(filter-out FORCE,$^) -o $@ 150 151# Objcopy 152# --------------------------------------------------------------------------- 153 154quiet_cmd_objcopy = OBJCOPY $@ 155cmd_objcopy = $(OBJCOPY) $(OBJCOPYFLAGS) $(OBJCOPYFLAGS_$(@F)) $< $@ 156 157# Gzip 158# --------------------------------------------------------------------------- 159 160quiet_cmd_gzip = GZIP $@ 161cmd_gzip = gzip -f -9 < $< > $@ 162 163 164