* Tore Anderson
> I think that file is only used if ARCH=xen. Which is correct for
> all released versions of Xen, but the new implementation that
> eventually will be merged into the kernel sources use ARCH=i386 (or
> x86_64), and then you choose Xen-compatible when asked for
> Subarchitecture Type under Processor type and features in
> menuconfig. This sets CONFIG_X86_XEN=y.
* Manoj Srivastava
> Have your tried make-kpkg with ARCH=xen? I think I see code
> that'll allowit to do the right thing.
Hmm. I think we're talking past each other. I'll try to explain.
When the Xen project started releasing kernel patches, they made Xen a
completely separate architecture. To build it you needed ARCH=xen.
All released versions of Xen use ARCH=xen, and make-kpkg are able to
build packages of these kernels just fine. This bug report is not
about those kernels, however.
Now, the Xen people wanted to have their code accepted into Linus'
tarball. However, the attitude of the people on LKML was something
like: «Why do you need a completely separate arch/xen/ when 90% of
the code is the same as in arch/i386/? Think about the code
duplication and the maintenance nightmare it will be. We won't accept
your patch before it improves on these issues.»
So the Xen people, determined on getting their code into Linus' tree,
went back to the drawing board and came up with a plan that should
please the LKML people. Instead of having Xen a separate architecture,
they made it a sub architecture of i386 (and x86_64, and in the future
probably all other architectures Xen is ported to as well). In
essence, that means that the arch/xen/ is removed, and all attempts to
build the kernel with ARCH=xen will just fail with an error message
such as (example of "make oldconfig" from the Mercurial pull of today):
Makefile:449: /usr/src/linux-2.6-xen/arch/xen/Makefile: No such file or
directory
make: *** No rule to make target
`/usr/src/linux-2.6-xen/arch/xen/Makefile'. Stop.
Instead, all Xen-specific code are moved to arch/i386/mach-xen/ (for
i386 at least).
Now, in order to build a Xen kernel, you make your *config target of
choice (using ARCH=i386), and when you are asked for "Subarchitecture
type" (where most people select "PC-compatible"), you must instead
select "Xen-compatible". This sets CONFIG_X86_XEN=y. Then you can go
on to build the kernel image as normal, still using ARCH=i386. But not
bzImage, only vmlinuz - that's where make-kpkg currently fail. My bug
report applies to these kernels only.
To the best of my knowlegde, the only way to obtain such a kernel
source is through the Mercurial repository. All released stable,
alpha, beta, etc. versions are the old ARCH=xen way. But that will
change as the Xen-as-subarch three reaches maturity; I doubt they want
to maintain two separate source trees for very long, and the ARCH=xen
way is a dead end due to the kernel maintainers' refusal to merge it.
It seems the Xen-as-subarch tree is where the developers are at too,
linux-2.6-xen.hg has been at 2.6.15 for some time, while
xen-unstable.hg (where the most recent ARCH=xen code is found) is
still at 2.6.12.
I hope that cleared things up? :-)
Kind regards
--
Tore Anderson
