[dpdk-dev] meson support : cross compile issues

[Hemant Agrawal]

Hi Bruce,

> On Tue, Feb 27, 2018 at 02:38:53PM +0000, Hemant Agrawal wrote:
> > Hi,
> >
> > How do we set CROSS COMPILE kernel path support. E.g. something
> > equivalent to RTE_KERNELDIR for Makefile
> >
> >      *   Currently the Igb_uio  compilation fails.
> >      *   Also, there is no check to disable igb_uio compilation by flag e.g.
> CONFIG_RTE_EAL_IGB_UIO=n
> >
> >
> 
> I have not had time to look at the cross-compilation of kernel modules yet, so
> patches welcome. :-) However, it should be possible to disable the kernel
> modules generally using "enable_kmods" option (see meson_options.txt)

[Hemant]  setting kernel_dir in meson_options.txt worked for me.
> 
> >
> > Other minor issue observed is that though the cross compile is set as 6.3, the
> gcc 7 flags (which is my host compiler version) is getting enabled.  Causing
> following errors:
> >
> 
> Actually, this is a gcc quirk. GCC does not report an error for cmdline flags
> disabling unknown warnings, unless other errors are displayed. This means that
> when meson tries the options, GCC reports as supporting them. It also means
> that it's not a problem when you do see them - just fix the other errors and the
> warnings about the flags will disappear.
> 
> See:
> https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgcc.gn
> u.org%2Fonlinedocs%2Fgcc%2FWarning-
> Options.html&data=02%7C01%7Chemant.agrawal%40nxp.com%7Cbe391f8ced
> e54b43679808d57df1b4e4%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C
> 1%7C636553399436715184&sdata=u3wSqw8DJ6dROat%2B%2BUr2EeusPmv90Z
> GPYRvitUuWIHE%3D&reserved=0
> "However, if the -Wno- form is used, the behavior is slightly different:
> no diagnostic is produced for -Wno-unknown-warning unless other diagnostics
> are being produced. This allows the use of new -Wno- options with old
> compilers, but if something goes wrong, the compiler warns that an
> unrecognized option is present"

[Hemant]  Thanks it helps.

> 
> 
> > ../drivers/bus/dpaa/dpaa_bus.c: At top level:
> >
> > cc1: warning: unrecognized command line option ‘-Wno-format-truncation’
> >
> > cc1: warning: unrecognized command line option ‘-Wno-address-of-packed-
> member’
> >
> > Regards,
> > Hemant
> >
> Regards,
> /Bruce