Re: [dpdk-dev] [PATCH 2/2] doc: add pkg-config-aarch64-linux-gnu as a prerequisite

[Ali Alnubani <alialnu@mellanox.com>]

> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Tuesday, November 26, 2019 2:01 PM
> To: Ali Alnubani <alialnu@mellanox.com>
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 2/2] doc: add pkg-config-aarch64-linux-gnu
> as a prerequisite
> 
> On Tue, Nov 26, 2019 at 10:41:08AM +0000, Ali Alnubani wrote:
> > Hi Bruce,
> >
> > > -----Original Message-----
> > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > Sent: Tuesday, November 26, 2019 11:52 AM
> > > To: Ali Alnubani <alialnu@mellanox.com>
> > > Cc: dev@dpdk.org
> > > Subject: Re: [dpdk-dev] [PATCH 2/2] doc: add
> > > pkg-config-aarch64-linux-gnu as a prerequisite
> > >
> > > On Tue, Nov 26, 2019 at 08:14:25AM +0000, Ali Alnubani wrote:
> > > > The package pkg-config-aarch64-linux-gnu is required with meson
> > > > for detecting dependencies installed in nonstandard paths.
> > > >
> > > > Signed-off-by: Ali Alnubani <alialnu@mellanox.com>
> > > > ---
> > > >  doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst | 8 ++++++++
> > > >  1 file changed, 8 insertions(+)
> > > >
> > > > diff --git a/doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst
> > > > b/doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst
> > > > index e799b0ba4..f00f9b130 100644
> > > > --- a/doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst
> > > > +++ b/doc/guides/linux_gsg/cross_build_dpdk_for_arm64.rst
> > > > @@ -122,6 +122,14 @@ To compile for non-NUMA targets, without
> > > > compiling the kernel modules, use the f  Meson Cross Compiling
> > > > DPDK
> > > >  --------------------------
> > > >
> > > > +Meson depends on pkgconfig to find the dependencies that are
> > > > +installed in nonstandard paths. The package
> > > > +`pkg-config-aarch64-linux-gnu` is required in this case. To
> > > > +install it in
> > > Ubuntu:
> > > > +
> > > > +.. code-block:: console
> > > > +
> > > > +   sudo apt-get install pkg-config-aarch64-linux-gnu
> > > > +
> > > >  To cross-compile DPDK on a desired target machine we can use the
> > > > following
> > > >  command::
> > >
> > > Is there a package for Fedora or similar Redhat-derived distros?
> >
> > I don't think it's available. Should I add instructions on how to cross build it
> instead of the apt-get example?
> >
> I think you might need both. Distro-instructions is probably best, but there
> are a lot of people not using Ubuntu, I suspect.
> 
> Following patch 1, if pkg-config is added to all the cross-build files, does that
> prevent previously working cross-builds from passing due to the lack of the
> pkg-config package? Do the travis jobs need updating, for example?

Cross compiling pkg-config from source requires glib, which in turn requires other packages (libffi and pcre).
Do we want to add instructions to cross build that dependency tree?

I opened a pull request to the Github mirror to make sure I didn't break the CI:
https://github.com/DPDK/dpdk/pull/14
If the binary 'aarch64-linux-gnu-pkg-config' isn't found, Meson seems to just show the following warnings, but it doesn't fail with error:
'''
Did not find pkg-config by name 'aarch64-linux-gnu-pkg-config'
Found Pkg-config: NO
'''

I'll send v2 with an additional patch to add the package to the list of requirements for Travis's environment.
> 
> /Bruce

- Ali