Re: building a debian kernel package(s) for a foreign architecture
Dear Jonathan,
How is your build? Does it go well?
On Thu, Jul 6, 2017 at 2:38 AM, Ben Hutchings <ben@decadent.org.uk> wrote:
> On Wed, 2017-07-05 at 23:43 +0900, Roger Shimizu wrote:
>>
>> I ever created one:
>> - https://wiki.debian.org/HowToCrossBuildAnOfficialDebianKernelPackage
>>
>> Hope it helps you.
>> And if you find something not current and need modify, please just edit it.
>> Thank you!
>
> Why does that talk about building from the git repository, rather than
> a source package (which duplicates the instructions at
> https://kernel-handbook.alioth.debian.org/ch-common-tasks.html)?
>
> For cross-building generally you should use the 'cross' build profile.
> And for linux specifically you can also use the 'pkg.linux.notools'
> build profile to disable the userland packages, which greatly reduces,
> the build depdendencies.
Dear Ben,
I created the wiki entry because I want to explorer some other ways
than what's telling in the kernel handbook. Of course I take the
handbook as reference, and thanks for your work!
It's easy to reproduce a kernel build by the steps in kernel handbook,
but what I want, sometimes, is to try the latest stable kernel
released upstream. Debian usually lags a few days behind upstream's
new release, especially in the freeze stage before a debian release.
So I think my wiki entry is informative in such case.
And I happened to find another topic in kernel lists:
- http://debian.2.n7.nabble.com/cross-building-linux-image-packages-td3974626.html
I tried your suggested command:
dpkg-buildpackage -Pcross,nopython -aarmel -B -uc -us
but got the following error:
====
dpkg-source: error: cannot read debian-kernel/debian/control: No such
file or directory
dpkg-buildpackage: error: dpkg-source --before-build debian-kernel
gave error exit status 2
====
On Thu, Jul 6, 2017 at 2:53 AM, Karsten Merker <merker@debian.org> wrote:
> On Wed, Jul 05, 2017 at 03:35:25PM +0100, Jonathan Dowland wrote:
>> Hi folks,
>>
>> I've never done much in the way of cross-compiling before. I
>> understand it was once very hard, is now much easier, and is
>> considerably easier for "simple" packages (including the kernel)
>> than others.
>>
>> That said, I'm lost/stuck trying to cross-compile the Debian
>> Linux kernel package for ARM64 (target is a Raspberry Pi 3) from
>> an amd64 builder. I believe I do not need to use multiarch for
>> my builder, yet dpkg-buildpackage (if I supply -a aarch64,
>> interestingly ARM64 doesn't work) complains of unmet build
>> dependencies, which I have resolved for amd64. But perhaps -a to
>> dpkg-buildpackage is the wrong approach.
>
> Hello,
>
> from a technical point of view you effectively need multiarch to
> crosscompile Debian packages, but you don't have to set it up
> yourself ;-).
>
> The easiest way to crossbuild a Debian package is probably to use
> sbuild or pbuilder, which both have crossbuild-support since a
> while. When called with the appropriate options, they
> automatically setup multiarch in their chroot and install the
> necessary crosscompilers as well as the package cross-dependencies.
> I can only talk about sbuild from personal experience, but
> according to the docs, pbuilder should work similarly.
>
> Not all packages can be crossbuilt, and for those that can be
> crossbuilt in principle, it is sometimes necessary to set
> appropriate build-profiles which e.g. cause the testsuite not to
> be run during the package build, as often the testsuite tries to
> run host-architecture binaries created during the build which
> cannot be executed on the build-architecture system (with "build"
> and "host" used in GNU terminology, i.e. "build-architecture" =
> "architecture on which the compiler runs" and "host-architecture" =
> "architeture on which the created binaries run").
>
> IIRC both pbuilder and sbuild automatically set the "nocheck"
> profile when crossbuilding. For crossbuilding the kernel IIRC
> one needs to set a number of additional build-profiles:
>
> - cross
> - pkg.linux.notools
> - nopython
>
> So the following sbuild command should in theory (sorry, cannot
> actually test that right now) crossbuild the kernel package for
> arm64:
>
> sbuild -d unstable --host=arm64 --profiles=cross,pkg.linux.notools,nopython <kernelpackage>.dsc
Thanks for your sample on sbuild, and detailed profile options.
I usually use git-pbuild for other packages. I hasn't figure out how
to do cross build kernel under pbuilder or its related tool (e.g.
git-build)
So if anybody know it, please let me know. Thanks!
Cheers,
--
Roger Shimizu, GMT +9 Tokyo
PGP/GPG: 4096R/6C6ACD6417B3ACB1
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