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-rw-r--r--Makefile146
1 files changed, 81 insertions, 65 deletions
diff --git a/Makefile b/Makefile
index bcf2e7628fe5..a61a95b6b38f 100644
--- a/Makefile
+++ b/Makefile
@@ -96,56 +96,65 @@ endif
export quiet Q KBUILD_VERBOSE
-# kbuild supports saving output files in a separate directory.
-# To locate output files in a separate directory two syntaxes are supported.
-# In both cases the working directory must be the root of the kernel src.
+# Kbuild will save output files in the current working directory.
+# This does not need to match to the root of the kernel source tree.
+#
+# For example, you can do this:
+#
+# cd /dir/to/store/output/files; make -f /dir/to/kernel/source/Makefile
+#
+# If you want to save output files in a different location, there are
+# two syntaxes to specify it.
+#
# 1) O=
# Use "make O=dir/to/store/output/files/"
#
# 2) Set KBUILD_OUTPUT
-# Set the environment variable KBUILD_OUTPUT to point to the directory
-# where the output files shall be placed.
-# export KBUILD_OUTPUT=dir/to/store/output/files/
-# make
+# Set the environment variable KBUILD_OUTPUT to point to the output directory.
+# export KBUILD_OUTPUT=dir/to/store/output/files/; make
#
# The O= assignment takes precedence over the KBUILD_OUTPUT environment
# variable.
-# KBUILD_SRC is not intended to be used by the regular user (for now),
-# it is set on invocation of make with KBUILD_OUTPUT or O= specified.
-
-# OK, Make called in directory where kernel src resides
-# Do we want to locate output files in a separate directory?
+# Do we want to change the working directory?
ifeq ("$(origin O)", "command line")
KBUILD_OUTPUT := $(O)
endif
-ifneq ($(words $(subst :, ,$(CURDIR))), 1)
- $(error main directory cannot contain spaces nor colons)
+ifneq ($(KBUILD_OUTPUT),)
+# Make's built-in functions such as $(abspath ...), $(realpath ...) cannot
+# expand a shell special character '~'. We use a somewhat tedious way here.
+abs_objtree := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) && pwd)
+$(if $(abs_objtree),, \
+ $(error failed to create output directory "$(KBUILD_OUTPUT)"))
+
+# $(realpath ...) resolves symlinks
+abs_objtree := $(realpath $(abs_objtree))
+else
+abs_objtree := $(CURDIR)
+endif # ifneq ($(KBUILD_OUTPUT),)
+
+ifeq ($(abs_objtree),$(CURDIR))
+# Suppress "Entering directory ..." unless we are changing the work directory.
+MAKEFLAGS += --no-print-directory
+else
+need-sub-make := 1
endif
-ifneq ($(KBUILD_OUTPUT),)
-# check that the output directory actually exists
-saved-output := $(KBUILD_OUTPUT)
-KBUILD_OUTPUT := $(shell mkdir -p $(KBUILD_OUTPUT) && cd $(KBUILD_OUTPUT) \
- && pwd)
-$(if $(KBUILD_OUTPUT),, \
- $(error failed to create output directory "$(saved-output)"))
+abs_srctree := $(realpath $(dir $(lastword $(MAKEFILE_LIST))))
+ifneq ($(words $(subst :, ,$(abs_srctree))), 1)
+$(error source directory cannot contain spaces or colons)
+endif
+
+ifneq ($(abs_srctree),$(abs_objtree))
# Look for make include files relative to root of kernel src
#
# This does not become effective immediately because MAKEFLAGS is re-parsed
-# once after the Makefile is read. It is OK since we are going to invoke
-# 'sub-make' below.
-MAKEFLAGS += --include-dir=$(CURDIR)
-
+# once after the Makefile is read. We need to invoke sub-make.
+MAKEFLAGS += --include-dir=$(abs_srctree)
need-sub-make := 1
-else
-
-# Do not print "Entering directory ..." at all for in-tree build.
-MAKEFLAGS += --no-print-directory
-
-endif # ifneq ($(KBUILD_OUTPUT),)
+endif
ifneq ($(filter 3.%,$(MAKE_VERSION)),)
# 'MAKEFLAGS += -rR' does not immediately become effective for GNU Make 3.x
@@ -155,20 +164,19 @@ need-sub-make := 1
$(lastword $(MAKEFILE_LIST)): ;
endif
+export abs_srctree abs_objtree
export sub_make_done := 1
ifeq ($(need-sub-make),1)
PHONY += $(MAKECMDGOALS) sub-make
-$(filter-out _all sub-make $(CURDIR)/Makefile, $(MAKECMDGOALS)) _all: sub-make
+$(filter-out _all sub-make $(lastword $(MAKEFILE_LIST)), $(MAKECMDGOALS)) _all: sub-make
@:
# Invoke a second make in the output directory, passing relevant variables
sub-make:
- $(Q)$(MAKE) \
- $(if $(KBUILD_OUTPUT),-C $(KBUILD_OUTPUT) KBUILD_SRC=$(CURDIR)) \
- -f $(CURDIR)/Makefile $(filter-out _all sub-make,$(MAKECMDGOALS))
+ $(Q)$(MAKE) -C $(abs_objtree) -f $(abs_srctree)/Makefile $(MAKECMDGOALS)
endif # need-sub-make
endif # sub_make_done
@@ -213,16 +221,21 @@ ifeq ("$(origin M)", "command line")
KBUILD_EXTMOD := $(M)
endif
-ifeq ($(KBUILD_SRC),)
+ifeq ($(abs_srctree),$(abs_objtree))
# building in the source tree
srctree := .
else
- ifeq ($(KBUILD_SRC)/,$(dir $(CURDIR)))
+ ifeq ($(abs_srctree)/,$(dir $(abs_objtree)))
# building in a subdirectory of the source tree
srctree := ..
else
- srctree := $(KBUILD_SRC)
+ srctree := $(abs_srctree)
endif
+
+ # TODO:
+ # KBUILD_SRC is only used to distinguish in-tree/out-of-tree build.
+ # Replace it with $(srctree) or something.
+ KBUILD_SRC := $(abs_srctree)
endif
export KBUILD_CHECKSRC KBUILD_EXTMOD KBUILD_SRC
@@ -436,7 +449,7 @@ USERINCLUDE := \
LINUXINCLUDE := \
-I$(srctree)/arch/$(SRCARCH)/include \
-I$(objtree)/arch/$(SRCARCH)/include/generated \
- $(if $(KBUILD_SRC), -I$(srctree)/include) \
+ $(if $(filter .,$(srctree)),,-I$(srctree)/include) \
-I$(objtree)/include \
$(USERINCLUDE)
@@ -497,7 +510,7 @@ PHONY += outputmakefile
# At the same time when output Makefile generated, generate .gitignore to
# ignore whole output directory
outputmakefile:
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
$(Q)ln -fsn $(srctree) source
$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkmakefile $(srctree)
$(Q)test -e .gitignore || \
@@ -520,15 +533,6 @@ KBUILD_AFLAGS += $(CLANG_FLAGS)
export CLANG_FLAGS
endif
-RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
-RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
-RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
-RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
-RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
-RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
-export RETPOLINE_CFLAGS
-export RETPOLINE_VDSO_CFLAGS
-
# The expansion should be delayed until arch/$(SRCARCH)/Makefile is included.
# Some architectures define CROSS_COMPILE in arch/$(SRCARCH)/Makefile.
# CC_VERSION_TEXT is referenced from Kconfig (so it needs export),
@@ -595,20 +599,21 @@ endif
export KBUILD_MODULES KBUILD_BUILTIN
+ifeq ($(dot-config),1)
+include include/config/auto.conf
+endif
+
ifeq ($(KBUILD_EXTMOD),)
# Objects we will link into vmlinux / subdirs we need to visit
init-y := init/
drivers-y := drivers/ sound/
+drivers-$(CONFIG_SAMPLES) += samples/
net-y := net/
libs-y := lib/
core-y := usr/
virt-y := virt/
endif # KBUILD_EXTMOD
-ifeq ($(dot-config),1)
-include include/config/auto.conf
-endif
-
# The all: target is the default when no target is given on the
# command line.
# This allow a user to issue only 'make' to build a kernel including modules
@@ -625,6 +630,15 @@ ifdef CONFIG_FUNCTION_TRACER
CC_FLAGS_FTRACE := -pg
endif
+RETPOLINE_CFLAGS_GCC := -mindirect-branch=thunk-extern -mindirect-branch-register
+RETPOLINE_VDSO_CFLAGS_GCC := -mindirect-branch=thunk-inline -mindirect-branch-register
+RETPOLINE_CFLAGS_CLANG := -mretpoline-external-thunk
+RETPOLINE_VDSO_CFLAGS_CLANG := -mretpoline
+RETPOLINE_CFLAGS := $(call cc-option,$(RETPOLINE_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_CFLAGS_CLANG)))
+RETPOLINE_VDSO_CFLAGS := $(call cc-option,$(RETPOLINE_VDSO_CFLAGS_GCC),$(call cc-option,$(RETPOLINE_VDSO_CFLAGS_CLANG)))
+export RETPOLINE_CFLAGS
+export RETPOLINE_VDSO_CFLAGS
+
# The arch Makefile can set ARCH_{CPP,A,C}FLAGS to override the default
# values of the respective KBUILD_* variables
ARCH_CPPFLAGS :=
@@ -985,8 +999,9 @@ vmlinux-dirs := $(patsubst %/,%,$(filter %/, $(init-y) $(init-m) \
$(core-y) $(core-m) $(drivers-y) $(drivers-m) \
$(net-y) $(net-m) $(libs-y) $(libs-m) $(virt-y)))
-vmlinux-alldirs := $(sort $(vmlinux-dirs) $(patsubst %/,%,$(filter %/, \
- $(init-) $(core-) $(drivers-) $(net-) $(libs-) $(virt-))))
+vmlinux-alldirs := $(sort $(vmlinux-dirs) Documentation \
+ $(patsubst %/,%,$(filter %/, $(init-) $(core-) \
+ $(drivers-) $(net-) $(libs-) $(virt-))))
init-y := $(patsubst %/, %/built-in.a, $(init-y))
core-y := $(patsubst %/, %/built-in.a, $(core-y))
@@ -1003,7 +1018,7 @@ export KBUILD_VMLINUX_LIBS := $(libs-y1)
export KBUILD_LDS := arch/$(SRCARCH)/kernel/vmlinux.lds
export LDFLAGS_vmlinux
# used by scripts/package/Makefile
-export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch Documentation include samples scripts tools)
+export KBUILD_ALLDIRS := $(sort $(filter-out arch/%,$(vmlinux-alldirs)) arch include scripts tools)
vmlinux-deps := $(KBUILD_LDS) $(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)
@@ -1040,11 +1055,8 @@ vmlinux: scripts/link-vmlinux.sh autoksyms_recursive $(vmlinux-deps) FORCE
targets := vmlinux
-# Build samples along the rest of the kernel. This needs headers_install.
-ifdef CONFIG_SAMPLES
-vmlinux-dirs += samples
+# Some samples need headers_install.
samples: headers_install
-endif
# The actual objects are generated when descending,
# make sure no implicit rule kicks in
@@ -1064,7 +1076,7 @@ filechk_kernel.release = \
echo "$(KERNELVERSION)$$($(CONFIG_SHELL) $(srctree)/scripts/setlocalversion $(srctree))"
# Store (new) KERNELRELEASE string in include/config/kernel.release
-include/config/kernel.release: $(srctree)/Makefile FORCE
+include/config/kernel.release: FORCE
$(call filechk,kernel.release)
# Additional helpers built in scripts/
@@ -1086,9 +1098,11 @@ PHONY += prepare archprepare prepare1 prepare3
# and if so do:
# 1) Check that make has not been executed in the kernel src $(srctree)
prepare3: include/config/kernel.release
-ifneq ($(KBUILD_SRC),)
+ifneq ($(srctree),.)
@$(kecho) ' Using $(srctree) as source for kernel'
- $(Q)if [ -f $(srctree)/.config -o -d $(srctree)/include/config ]; then \
+ $(Q)if [ -f $(srctree)/.config -o \
+ -d $(srctree)/include/config -o \
+ -d $(srctree)/arch/$(SRCARCH)/include/generated ]; then \
echo >&2 " $(srctree) is not clean, please run 'make mrproper'"; \
echo >&2 " in the '$(srctree)' directory.";\
/bin/false; \
@@ -1304,6 +1318,7 @@ _modinst_:
fi
@cp -f $(objtree)/modules.order $(MODLIB)/
@cp -f $(objtree)/modules.builtin $(MODLIB)/
+ @cp -f $(objtree)/modules.builtin.modinfo $(MODLIB)/
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modinst
# This depmod is only for convenience to give the initial
@@ -1344,10 +1359,11 @@ endif # CONFIG_MODULES
# Directories & files removed with 'make clean'
CLEAN_DIRS += $(MODVERDIR) include/ksym
+CLEAN_FILES += modules.builtin.modinfo
# Directories & files removed with 'make mrproper'
MRPROPER_DIRS += include/config usr/include include/generated \
- arch/*/include/generated .tmp_objdiff
+ arch/$(SRCARCH)/include/generated .tmp_objdiff
MRPROPER_FILES += .config .config.old .version \
Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS \
signing_key.pem signing_key.priv signing_key.x509 \
@@ -1358,7 +1374,7 @@ MRPROPER_FILES += .config .config.old .version \
#
clean: rm-dirs := $(CLEAN_DIRS)
clean: rm-files := $(CLEAN_FILES)
-clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs) Documentation samples)
+clean-dirs := $(addprefix _clean_, . $(vmlinux-alldirs))
PHONY += $(clean-dirs) clean archclean vmlinuxclean
$(clean-dirs):