Sam,
is there any reason your patch from June still isn't merged?
# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
# 2004/06/14 22:21:46+02:00 [email protected]
# kbuild: Add external module documentation
#
# Add first version of a document describing how to build external modules.
# This is not yet finished, but includes information that is nice to have
# documented in the kernel even in a less complete form.
#
# Signed-off-by: Sam Ravnborg <[email protected]>
#
# Documentation/kbuild/extmodules.txt
# 2004/06/14 22:21:32+02:00 [email protected] +168 -0
#
# Documentation/kbuild/extmodules.txt
# 2004/06/14 22:21:32+02:00 [email protected] +0 -0
# BitKeeper file /home/sam/bk/kbuild/Documentation/kbuild/extmodules.txt
#
# Documentation/kbuild/00-INDEX
# 2004/06/14 22:21:32+02:00 [email protected] +2 -0
# Added extmodules.txt
#
diff -Nru a/Documentation/kbuild/00-INDEX b/Documentation/kbuild/00-INDEX
--- a/Documentation/kbuild/00-INDEX 2004-06-14 22:25:21 +02:00
+++ b/Documentation/kbuild/00-INDEX 2004-06-14 22:25:21 +02:00
@@ -6,3 +6,5 @@
- developer information for linux kernel makefiles
modules.txt
- how to build modules and to install them
+extmodules.txt
+ - specific information about external modules
diff -Nru a/Documentation/kbuild/extmodules.txt b/Documentation/kbuild/extmodules.txt
--- /dev/null Wed Dec 31 16:00:00 196900
+++ b/Documentation/kbuild/extmodules.txt 2004-06-14 22:25:21 +02:00
@@ -0,0 +1,168 @@
+Building external modules
+=========================
+kbuild offers functionality to build external modules, with the
+prerequisite that there is a pre-built kernel avialable with full source.
+A subset of the targets available when building the kernel is available
+when building an external module.
+
+
+Building the module
+-------------------
+The command looks like his:
+
+ make -C <path to kernel src> M=`pwd`
+
+For the above command to succeed the kernel must have been built with
+modules enabled.
+
+To install the modules just being built:
+
+ make -C <path to kernel src> M=`pwd` modules_install
+
+More complex examples later, the above should get you going in most cases.
+
+
+Available targets
+- - - - - - - - -
+$KDIR refer to path to kernel src
+
+make -C $KDIR M=`pwd`
+ Will build the module(s) located in current directory. All output
+ files will be located in the same directory as the module source.
+ No attemps are made to update the kernel source, and it is
+ expected that a successfully make has been executed
+ for the kernel.
+
+make -C $KDIR M=`pwd` modules
+ Same as if no target was specified. See description above.
+
+make -C $KDIR M=$PWD modules_install
+ Install the external module(s)
+
+make -C $KDIR M=$PWD clean
+ Remove all generated files in for the module - not the kernel
+
+make -C $KDIR M=`pwd` help
+ help will list the available target when building external
+ modules.
+
+Available options:
+- - - - - - - - -
+$KDIR refer to path to kernel src
+
+make -C $KDIR
+ Used to specify where to find the kernel source.
+ '$KDIR' represent the directory where the kernel source is.
+ Make will actually change directory to the specified directory
+ when executed but change back when finished.
+
+make -C $KDIR M=`pwd`
+ M= is used to tell kbuild that an external module is being built.
+ The option given to M= is the directory where the external
+ module is located.
+ When an external module is being built only a subset of the
+ usual targets are avialable.
+
+make -C $KDIR SUBDIRS=`pwd`
+ Same as M=. The SUBDIRS= syntax is kept for backwards compatibility.
+
+
+A more advanced example
+- - - - - - - - - - - -
+This example shows a setup where a distribution has wisely decided
+to separate kernel source and output files:
+
+Kernel src:
+/usr/src/linux-<kernel-version>/
+
+Output from a kernel compile, including .config:
+/lib/modules/linux-<kernel-version>/build/
+
+External module to be compiled:
+/home/user/module/src/
+
+To compile the module located in the directory above use the
+following command:
+
+ cd /home/user/module/src
+ make -C /usr/src/linux-<kernel-version> \
+ O=/lib/modules/linux-<kernel-version>/build \
+ M=`pwd`
+
+Then to install the module use the following command:
+
+ make -C /usr/src/linux-<kernel-version> \
+ O=/lib/modules/linux-<kernel-version>/build \
+ M='pwd` modules_install
+
+The above are rather long commands, and the following chapter
+lists a few tricks to make it all easier.
+
+Tricks to make it easy
+---------------------
+TODO: .... This need to be rewritten......
+
+A make line with several parameters becomes tiresome and errorprone
+and what follows here is a little trick to make it possible to build
+a module only using a single 'make' command.
+
+Create a makefile named 'Makefile' with the following content:
+---> Makefile:
+
+all:
+ $(MAKE) -C /home/sam/src/kernel/v2.6 M=`pwd` \
+ $(filter-out all,$(MAKECMDGOALS))
+
+obj-m := module.o
+---> End of Makefile
+
+When make is invoked it will see the all: rule, and simply call make again with the right parameters.
+
+If a driver is being developed that is targeted for inclusion in the main kernel, an idea is to seperate out the all: rule to a Makefile nemed makefile (lower capital m) like this:
+
+---> makefile
+all:
+ $(MAKE) -f Makefile -C /home/sam/src/kernel/v2.6 \
+ M=$(PWD) $(MAKECMDGOALS)
+
+---> End of makefile
+
+The kbuild makefile will include only a single statement:
+---> Makefile:
+
+obj-m := module.o
+
+---> End of Makefile
+When executing make, it looks for a file named makefile, before a
+file named Makefile. Therefor make will pick up the file named with lower capital 'm'.
+
+
+Prepare the kernel for building external modules
+------------------------------------------------
+When building external modules the kernel is expected to be prepared.
+This includes the precense of certain binaries, the kernel configuration
+and the symlink to include/asm.
+To do this a convinient target is made:
+
+ make modules_prepare
+
+For a typical distribution this would look like the follwoing:
+
+ make modules_prepare O=/lib/modules/linux-<kernel version>/build
+
+
+TODO: Fill out the following chapters
+
+Module versioning
+-----------------
+
+Include files targeted towards kernel include/...
+-------------------------------------------------
+
+Local include files
+-------------------
+
+Binary only .o files
+--------------------
+Use _shipped.
+
On Saturday 18 of September 2004 13:29, Christoph Hellwig wrote:
> Sam,
>
> is there any reason your patch from June still isn't merged?
>
[...]
> +Prepare the kernel for building external modules
> +------------------------------------------------
> +When building external modules the kernel is expected to be prepared.
> +This includes the precense of certain binaries, the kernel configuration
> +and the symlink to include/asm.
> +To do this a convinient target is made:
> +
> + make modules_prepare
> +
> +For a typical distribution this would look like the follwoing:
> +
> + make modules_prepare O=/lib/modules/linux-<kernel version>/build
Tthis means that one, unmodified source tree is _not_ usable for multiple
architectures. You can't use the same, prepared sources and for example
create noarch.rpm or burn on cd and then use for external modules building on
different architectures.
We are using this:
http://cvs.pld-linux.org/cgi-bin/cvsweb/SOURCES/linux-kbuild-extmod.patch?rev=1.2
to get external modules working for multiple archs with the same sources:
http://cvs.pld-linux.org/cgi-bin/cvsweb/SPECS/template-kernel-module.spec?rev=1.14
--
Arkadiusz Mi?kiewicz PLD/Linux Team
http://www.t17.ds.pwr.wroc.pl/~misiek/ http://ftp.pld-linux.org/
On Sat, Sep 18, 2004 at 01:29:00PM +0200, Christoph Hellwig wrote:
> Sam,
>
> is there any reason your patch from June still isn't merged?
It need a few hours update and I have been to spoiled to do it.
Will look at it pretty soon - thanks for reminder.
Sam
On Thu, Sep 23, 2004 at 10:24:50PM +0200, Arkadiusz Miskiewicz wrote:
> On Saturday 18 of September 2004 13:29, Christoph Hellwig wrote:
> > Sam,
> >
> > is there any reason your patch from June still isn't merged?
> >
> [...]
> > +Prepare the kernel for building external modules
> > +------------------------------------------------
> > +When building external modules the kernel is expected to be prepared.
> > +This includes the precense of certain binaries, the kernel configuration
> > +and the symlink to include/asm.
> > +To do this a convinient target is made:
> > +
> > + make modules_prepare
> > +
> > +For a typical distribution this would look like the follwoing:
> > +
> > + make modules_prepare O=/lib/modules/linux-<kernel version>/build
> Tthis means that one, unmodified source tree is _not_ usable for multiple
> architectures. You can't use the same, prepared sources and for example
> create noarch.rpm or burn on cd and then use for external modules building on
> different architectures.
You are doing it wrong.
You need in your case one source tree, several output dirs.
So use
make ARCH=sparc CROSS_COMPILE=xxx O=~/build/sparc ...
make ARCH=ppc CROSS_COMPILE=xxx O=~/build/ppc ...
The patch below is flawed.
>
> We are using this:
> http://cvs.pld-linux.org/cgi-bin/cvsweb/SOURCES/linux-kbuild-extmod.patch?rev=1.2
> to get external modules working for multiple archs with the same sources:
> http://cvs.pld-linux.org/cgi-bin/cvsweb/SPECS/template-kernel-module.spec?rev=1.14
Sam
On Monday 27 of September 2004 09:25, Sam Ravnborg wrote:
> > Tthis means that one, unmodified source tree is _not_ usable for multiple
> > architectures. You can't use the same, prepared sources and for example
> > create noarch.rpm or burn on cd and then use for external modules
> > building on different architectures.
>
> You are doing it wrong.
> You need in your case one source tree, several output dirs.
> So use
> make ARCH=sparc CROSS_COMPILE=xxx O=~/build/sparc ...
>
> make ARCH=ppc CROSS_COMPILE=xxx O=~/build/ppc ...
cross_compile? I don't want to make cross compilation. I want to use the same
source on my x86 machine, ppc machine, alpha machine, sparc machine and so
on. Since make in external modules dir doesn't create scripts and such kbuild
stuff I don't see how this can work with make modules_prepare.
Please explain.
> Sam
--
Arkadiusz Mi?kiewicz PLD/Linux Team
http://www.t17.ds.pwr.wroc.pl/~misiek/ http://ftp.pld-linux.org/