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authorSam Ravnborg <sam@mars.ravnborg.org>2006-01-25 07:13:18 +0100
committerSam Ravnborg <sam@mars.ravnborg.org>2006-02-19 09:51:17 +0100
commit06300b21f4c79fd1578f4b7ca4b314fbab61a383 (patch)
tree9b9506e34286f0333ed747c47ec03fd5559f5b71
parentbd71c2b17468a2531fb4c81ec1d73520845e97e1 (diff)
downloadlwn-06300b21f4c79fd1578f4b7ca4b314fbab61a383.tar.gz
lwn-06300b21f4c79fd1578f4b7ca4b314fbab61a383.zip
kbuild: support building individual files for external modules
Support building individual files when dealing with separate modules. So say you have a module named "foo" which consist of two .o files bar.o and fun.o. You can then do: make -C $KERNELSRC M=`pwd` bar.o make -C $KERNELSRC M=`pwd` bar.lst make -C $KERNELSRC M=`pwd` bar.i make -C $KERNELSRC M=`pwd` / <= will build all .o files and link foo.o make -C $KERNELSRC M=`pwd` foo.ko <= will build the module and do the modpost step to create foo.ko The above will also work if the external module is placed in a subdirectory using a hirachy of kbuild files. Thanks to Andreas Gruenbacher <agruen@suse.de> for initial feature request / bug report. Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
-rw-r--r--Documentation/kbuild/modules.txt11
-rw-r--r--Makefile66
2 files changed, 55 insertions, 22 deletions
diff --git a/Documentation/kbuild/modules.txt b/Documentation/kbuild/modules.txt
index 7e77f93634ea..87d858df4e34 100644
--- a/Documentation/kbuild/modules.txt
+++ b/Documentation/kbuild/modules.txt
@@ -13,6 +13,7 @@ In this document you will find information about:
--- 2.2 Available targets
--- 2.3 Available options
--- 2.4 Preparing the kernel tree for module build
+ --- 2.5 Building separate files for a module
=== 3. Example commands
=== 4. Creating a kbuild file for an external module
=== 5. Include files
@@ -131,6 +132,16 @@ when building an external module.
Therefore a full kernel build needs to be executed to make
module versioning work.
+--- 2.5 Building separate files for a module
+ It is possible to build single files which is part of a module.
+ This works equal for the kernel, a module and even for external
+ modules.
+ Examples (module foo.ko, consist of bar.o, baz.o):
+ make -C $KDIR M=`pwd` bar.lst
+ make -C $KDIR M=`pwd` bar.o
+ make -C $KDIR M=`pwd` foo.ko
+ make -C $KDIR M=`pwd` /
+
=== 3. Example commands
diff --git a/Makefile b/Makefile
index 77a448c8e776..639d8a48bbde 100644
--- a/Makefile
+++ b/Makefile
@@ -137,7 +137,7 @@ objtree := $(CURDIR)
src := $(srctree)
obj := $(objtree)
-VPATH := $(srctree)
+VPATH := $(srctree):$(KBUILD_EXTMOD)
export srctree objtree VPATH TOPDIR
@@ -849,27 +849,6 @@ prepare prepare-all: prepare0
export CPPFLAGS_vmlinux.lds += -P -C -U$(ARCH)
-# Single targets
-# ---------------------------------------------------------------------------
-
-%.s: %.c scripts FORCE
- $(Q)$(MAKE) $(build)=$(@D) $@
-%.i: %.c scripts FORCE
- $(Q)$(MAKE) $(build)=$(@D) $@
-%.o: %.c scripts FORCE
- $(Q)$(MAKE) $(build)=$(@D) $@
-%.ko: scripts FORCE
- $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) $(build)=$(@D) $(@:.ko=.o)
- $(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modpost
-%/: scripts prepare FORCE
- $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) $(build)=$(@D)
-%.lst: %.c scripts FORCE
- $(Q)$(MAKE) $(build)=$(@D) $@
-%.s: %.S scripts FORCE
- $(Q)$(MAKE) $(build)=$(@D) $@
-%.o: %.S scripts FORCE
- $(Q)$(MAKE) $(build)=$(@D) $@
-
# FIXME: The asm symlink changes when $(ARCH) changes. That's
# hard to detect, but I suppose "make mrproper" is a good idea
# before switching between archs anyway.
@@ -1192,6 +1171,11 @@ help:
@echo ' modules_install - install the module'
@echo ' clean - remove generated files in module directory only'
@echo ''
+
+# Dummies...
+.PHONY: prepare scripts
+prepare: ;
+scripts: ;
endif # KBUILD_EXTMOD
# Generate tags for editors
@@ -1313,6 +1297,44 @@ kernelrelease:
kernelversion:
@echo $(KERNELVERSION)
+# Single targets
+# ---------------------------------------------------------------------------
+# The directory part is taken from first prerequisite, so this
+# works even with external modules
+%.s: %.c scripts FORCE
+ $(Q)$(MAKE) $(build)=$(dir $<) $(dir $<)$(notdir $@)
+%.i: %.c scripts FORCE
+ $(Q)$(MAKE) $(build)=$(dir $<) $(dir $<)$(notdir $@)
+%.o: %.c scripts FORCE
+ $(Q)$(MAKE) $(build)=$(dir $<) $(dir $<)$(notdir $@)
+%.lst: %.c scripts FORCE
+ $(Q)$(MAKE) $(build)=$(dir $<) $(dir $<)$(notdir $@)
+%.s: %.S scripts FORCE
+ $(Q)$(MAKE) $(build)=$(dir $<) $(dir $<)$(notdir $@)
+%.o: %.S scripts FORCE
+ $(Q)$(MAKE) $(build)=$(dir $<) $(dir $<)$(notdir $@)
+
+# For external modules we shall include any directory of the target,
+# but usual case there is no directory part.
+# make M=`pwd` module.o => $(dir $@)=./
+# make M=`pwd` foo/module.o => $(dir $@)=foo/
+# make M=`pwd` / => $(dir $@)=/
+
+ifeq ($(KBUILD_EXTMOD),)
+ target-dir = $(@D)
+else
+ zap-slash=$(filter-out .,$(patsubst %/,%,$(dir $@)))
+ target-dir = $(KBUILD_EXTMOD)$(if $(zap-slash),/$(zap-slash))
+endif
+
+/ %/: scripts prepare FORCE
+ $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
+ $(build)=$(target-dir)
+%.ko: scripts FORCE
+ $(Q)$(MAKE) KBUILD_MODULES=$(if $(CONFIG_MODULES),1) \
+ $(build)=$(target-dir) $(@:.ko=.o)
+ $(Q)$(MAKE) -rR -f $(srctree)/scripts/Makefile.modpost
+
# FIXME Should go into a make.lib or something
# ===========================================================================