[dpdk-dev] [RFC PATCH v1] build: kni gcc cross-compilation support

[Bruce Richardson]

On Fri, Jan 29, 2021 at 02:47:57PM +0000, Juraj Linkeš wrote:
> 
> 
> > -----Original Message-----
> > From: Bruce Richardson <bruce.richardson at intel.com>
> > Sent: Friday, January 29, 2021 3:42 PM
> > To: Juraj Linkeš <juraj.linkes at pantheon.tech>
> > Cc: thomas at monjalon.net; Ruifeng.Wang at arm.com; jerinjacobk at gmail.com;
> > hemant.agrawal at nxp.com; ferruh.yigit at intel.com; aboyer at pensando.io;
> > dev at dpdk.org
> > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> > 
<snip>
> > > > Can we find some way of getting it working for both cases.
> > > > For native builds we want:
> > > >
> > > > * build kernel-dir = /lib/modules/<ver>/build
> > > > * install dir = /lib/modules/<ver>/extra/dpdk
> > > >
> > > > What are the expected equivalent paths for cross building?
> > > >
> > >
> > > The ubuntu1804 packages are installing aarch64 cross files to /usr/aarch64-
> > linux-gnu, so we could install it to /usr/aarch64-linux-
> > gnu/lib/modules/<ver>/extra/dpdk, or
> > /usr/<cross_triple>/lib/modules/<ver>/extra/dpdk in general. I think we can get
> > <ver> from 'make kernelversion', so that would work, although I'm not sure this
> > is the right place.
> > >
> > So what do you specify as the "kernel_dir" for the cross compile?
> > 
> 
> The place where I cloned (and cross-compiled) linux sources: $HOME/linux.
> 
So I think the key problem is that for cross-compilation you need two
completely independent paths, while for native builds the two can be
linked. Is that correct?