[RFC,v1] build: kni gcc cross-compilation support
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Commit Message
The kni linux module is using a custom target for building, which
doesn't take into account any cross compilation arguments. The arguments
in question are ARCH and CROSS_COMPILE. Get those from the cross file
and pass them to the custom target.
The user supplied path may not contain the 'build' directory, such as
when using cross-compiled headers, so only append that in the default
case (when no path is supplied in native builds) and use the unmodified
path from the user otherwise.
Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
---
kernel/linux/kni/meson.build | 4 ++--
kernel/linux/meson.build | 33 +++++++++++++++++++++++++++++----
2 files changed, 31 insertions(+), 6 deletions(-)
Comments
On Fri, Jan 29, 2021 at 11:29:19AM +0100, Juraj Linkeš wrote:
> The kni linux module is using a custom target for building, which
> doesn't take into account any cross compilation arguments. The arguments
> in question are ARCH and CROSS_COMPILE. Get those from the cross file
> and pass them to the custom target.
>
> The user supplied path may not contain the 'build' directory, such as
> when using cross-compiled headers, so only append that in the default
> case (when no path is supplied in native builds) and use the unmodified
> path from the user otherwise.
>
> Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> ---
> kernel/linux/kni/meson.build | 4 ++--
> kernel/linux/meson.build | 33 +++++++++++++++++++++++++++++----
> 2 files changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/linux/kni/meson.build b/kernel/linux/kni/meson.build
> index 07e0c9dae..0fbf52c93 100644
> --- a/kernel/linux/kni/meson.build
> +++ b/kernel/linux/kni/meson.build
> @@ -13,7 +13,7 @@ kni_sources = files(
> custom_target('rte_kni',
> input: kni_sources,
> output: 'rte_kni.ko',
> - command: ['make', '-j4', '-C', kernel_dir + '/build',
> + command: ['make', '-j4', '-C', kernel_dir,
> 'M=' + meson.current_build_dir(),
> 'src=' + meson.current_source_dir(),
> 'MODULE_CFLAGS=-include ' + meson.source_root() + '/config/rte_config.h' +
> @@ -21,7 +21,7 @@ custom_target('rte_kni',
> ' -I' + meson.source_root() + '/lib/librte_kni' +
> ' -I' + meson.build_root() +
> ' -I' + meson.current_source_dir(),
> - 'modules'],
> + 'modules'] + cross_args,
> depends: kni_mkfile,
> install: true,
> install_dir: kernel_dir + '/extra/dpdk',
> diff --git a/kernel/linux/meson.build b/kernel/linux/meson.build
> index 5c864a465..57ed9bc48 100644
> --- a/kernel/linux/meson.build
> +++ b/kernel/linux/meson.build
> @@ -3,20 +3,45 @@
>
> subdirs = ['kni']
>
> +cross_args = []
> # if we are cross-compiling we need kernel_dir specified
> -if get_option('kernel_dir') == '' and meson.is_cross_build()
> - error('Need "kernel_dir" option for kmod compilation when cross-compiling')
> +if meson.is_cross_build()
> + if get_option('kernel_dir') == ''
> + error('Need "kernel_dir" option for kmod compilation when cross-compiling')
> + else
> + cross_compiler = find_program('c').path()
> + if cross_compiler.endswith('gcc')
> + cross_prefix = ''
> + # remove the 'gcc' suffix
> + # meson doesn't support removing elements from an array
> + # nor does it support slicing, so do it on our own
> + foreach element : cross_compiler.split('-')
> + if element != 'gcc'
> + cross_prefix += '@0@-'.format(element)
> + endif
> + endforeach
> + else
> + error('Unsupported cross compiler: @0@'.format(cross_compiler))
> + endif
Rather than splitting manually, might it be better to just define a new
property in the cross-file to hold the prefix? Alternatively, rather than
meson looping, why not just use "run_command" to use shell or python to do
the job, e.g. [untested]
run_command([py3, '-c',
'print("-".join("' + cross_compiler + '".split("-")[:-1]))')
run_command('bash', '-c',
'echo ' + cross_compiler + ' | sed "s/gcc$//"')
> + if host_machine.cpu_family() == 'aarch64'
> + cross_arch = 'arm64'
> + else
> + cross_arch = build_machine.cpu_family()
> + endif
> + cross_args = ['ARCH=@0@'.format(cross_arch),
> + 'CROSS_COMPILE=@0@'.format(cross_prefix)]
> + endif
> endif
>
> kernel_dir = get_option('kernel_dir')
> if kernel_dir == ''
> # use default path for native builds
> kernel_version = run_command('uname', '-r').stdout().strip()
> - kernel_dir = '/lib/modules/' + kernel_version
> + kernel_dir = '/lib/modules/' + kernel_version + '/build'
> endif
The reason we don't keep the "build" off the kernel_dir is to ensure that
the kernel modules install to the correct place. With this change the
modules will go in "/lib/modules/<version>/build/extra/dpdk", rather than
"/lib/modules/<version>/extra/dpdk".
>
> # test running make in kernel directory, using "make kernelversion"
> -make_returncode = run_command('make', '-sC', kernel_dir + '/build',
> +make_returncode = run_command('make', '-sC', kernel_dir,
> 'kernelversion').returncode()
> if make_returncode != 0
> error('Cannot compile kernel modules as requested - are kernel headers installed?')
> --
> 2.20.1
>
> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Friday, January 29, 2021 12:44 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> dev@dpdk.org
> Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
>
> On Fri, Jan 29, 2021 at 11:29:19AM +0100, Juraj Linkeš wrote:
> > The kni linux module is using a custom target for building, which
> > doesn't take into account any cross compilation arguments. The
> > arguments in question are ARCH and CROSS_COMPILE. Get those from the
> > cross file and pass them to the custom target.
> >
> > The user supplied path may not contain the 'build' directory, such as
> > when using cross-compiled headers, so only append that in the default
> > case (when no path is supplied in native builds) and use the
> > unmodified path from the user otherwise.
> >
> > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > ---
> > kernel/linux/kni/meson.build | 4 ++--
> > kernel/linux/meson.build | 33 +++++++++++++++++++++++++++++----
> > 2 files changed, 31 insertions(+), 6 deletions(-)
> >
> > diff --git a/kernel/linux/kni/meson.build
> > b/kernel/linux/kni/meson.build index 07e0c9dae..0fbf52c93 100644
> > --- a/kernel/linux/kni/meson.build
> > +++ b/kernel/linux/kni/meson.build
> > @@ -13,7 +13,7 @@ kni_sources = files( custom_target('rte_kni',
> > input: kni_sources,
> > output: 'rte_kni.ko',
> > - command: ['make', '-j4', '-C', kernel_dir + '/build',
> > + command: ['make', '-j4', '-C', kernel_dir,
> > 'M=' + meson.current_build_dir(),
> > 'src=' + meson.current_source_dir(),
> > 'MODULE_CFLAGS=-include ' + meson.source_root() +
> > '/config/rte_config.h' + @@ -21,7 +21,7 @@ custom_target('rte_kni',
> > ' -I' + meson.source_root() + '/lib/librte_kni' +
> > ' -I' + meson.build_root() +
> > ' -I' + meson.current_source_dir(),
> > - 'modules'],
> > + 'modules'] + cross_args,
> > depends: kni_mkfile,
> > install: true,
> > install_dir: kernel_dir + '/extra/dpdk', diff --git
> > a/kernel/linux/meson.build b/kernel/linux/meson.build index
> > 5c864a465..57ed9bc48 100644
> > --- a/kernel/linux/meson.build
> > +++ b/kernel/linux/meson.build
> > @@ -3,20 +3,45 @@
> >
> > subdirs = ['kni']
> >
> > +cross_args = []
> > # if we are cross-compiling we need kernel_dir specified -if
> > get_option('kernel_dir') == '' and meson.is_cross_build()
> > - error('Need "kernel_dir" option for kmod compilation when cross-
> compiling')
> > +if meson.is_cross_build()
> > + if get_option('kernel_dir') == ''
> > + error('Need "kernel_dir" option for kmod compilation when
> cross-compiling')
> > + else
> > + cross_compiler = find_program('c').path()
> > + if cross_compiler.endswith('gcc')
> > + cross_prefix = ''
> > + # remove the 'gcc' suffix
> > + # meson doesn't support removing elements from an
> array
> > + # nor does it support slicing, so do it on our own
> > + foreach element : cross_compiler.split('-')
> > + if element != 'gcc'
> > + cross_prefix += '@0@-
> '.format(element)
> > + endif
> > + endforeach
> > + else
> > + error('Unsupported cross compiler:
> @0@'.format(cross_compiler))
> > + endif
>
> Rather than splitting manually, might it be better to just define a new property in
> the cross-file to hold the prefix?
That would by one more unnecessary input, so I don't like that.
> Alternatively, rather than meson looping, why
> not just use "run_command" to use shell or python to do the job, e.g. [untested]
>
> run_command([py3, '-c',
> 'print("-".join("' + cross_compiler + '".split("-")[:-1]))')
>
> run_command('bash', '-c',
> 'echo ' + cross_compiler + ' | sed "s/gcc$//"')
>
Since there isn't a better way to do this in Meson, it makes sense to use an external tool.
On top of that, this would save lines and wouldn't need as many code comments. I'll change it.
> > + if host_machine.cpu_family() == 'aarch64'
> > + cross_arch = 'arm64'
> > + else
> > + cross_arch = build_machine.cpu_family()
> > + endif
> > + cross_args = ['ARCH=@0@'.format(cross_arch),
> > + 'CROSS_COMPILE=@0@'.format(cross_prefix)]
> > + endif
> > endif
> >
> > kernel_dir = get_option('kernel_dir') if kernel_dir == ''
> > # use default path for native builds
> > kernel_version = run_command('uname', '-r').stdout().strip()
> > - kernel_dir = '/lib/modules/' + kernel_version
> > + kernel_dir = '/lib/modules/' + kernel_version + '/build'
> > endif
>
> The reason we don't keep the "build" off the kernel_dir is to ensure that the
> kernel modules install to the correct place. With this change the modules will go
> in "/lib/modules/<version>/build/extra/dpdk", rather than
> "/lib/modules/<version>/extra/dpdk".
>
Ah, I see. The modules will be installed during meson install. This should also be changed, then, as we always want to install them to '/lib/modules/<version>' (not necessarily to 'kernel_dir', as the user may change that) and only for native builds, right?
> >
> > # test running make in kernel directory, using "make kernelversion"
> > -make_returncode = run_command('make', '-sC', kernel_dir + '/build',
> > +make_returncode = run_command('make', '-sC', kernel_dir,
> > 'kernelversion').returncode()
> > if make_returncode != 0
> > error('Cannot compile kernel modules as requested - are kernel
> > headers installed?')
> > --
> > 2.20.1
> >
On Fri, Jan 29, 2021 at 12:33:06PM +0000, Juraj Linkeš wrote:
>
>
> > -----Original Message-----
> > From: Bruce Richardson <bruce.richardson@intel.com>
> > Sent: Friday, January 29, 2021 12:44 PM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> > hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> > dev@dpdk.org
> > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> >
> > On Fri, Jan 29, 2021 at 11:29:19AM +0100, Juraj Linkeš wrote:
> > > The kni linux module is using a custom target for building, which
> > > doesn't take into account any cross compilation arguments. The
> > > arguments in question are ARCH and CROSS_COMPILE. Get those from the
> > > cross file and pass them to the custom target.
> > >
> > > The user supplied path may not contain the 'build' directory, such as
> > > when using cross-compiled headers, so only append that in the default
> > > case (when no path is supplied in native builds) and use the
> > > unmodified path from the user otherwise.
> > >
> > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > ---
> > > kernel/linux/kni/meson.build | 4 ++--
> > > kernel/linux/meson.build | 33 +++++++++++++++++++++++++++++----
> > > 2 files changed, 31 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/kernel/linux/kni/meson.build
> > > b/kernel/linux/kni/meson.build index 07e0c9dae..0fbf52c93 100644
> > > --- a/kernel/linux/kni/meson.build
> > > +++ b/kernel/linux/kni/meson.build
> > > @@ -13,7 +13,7 @@ kni_sources = files( custom_target('rte_kni',
> > > input: kni_sources,
> > > output: 'rte_kni.ko',
> > > - command: ['make', '-j4', '-C', kernel_dir + '/build',
> > > + command: ['make', '-j4', '-C', kernel_dir,
> > > 'M=' + meson.current_build_dir(),
> > > 'src=' + meson.current_source_dir(),
> > > 'MODULE_CFLAGS=-include ' + meson.source_root() +
> > > '/config/rte_config.h' + @@ -21,7 +21,7 @@ custom_target('rte_kni',
> > > ' -I' + meson.source_root() + '/lib/librte_kni' +
> > > ' -I' + meson.build_root() +
> > > ' -I' + meson.current_source_dir(),
> > > - 'modules'],
> > > + 'modules'] + cross_args,
> > > depends: kni_mkfile,
> > > install: true,
> > > install_dir: kernel_dir + '/extra/dpdk', diff --git
> > > a/kernel/linux/meson.build b/kernel/linux/meson.build index
> > > 5c864a465..57ed9bc48 100644
> > > --- a/kernel/linux/meson.build
> > > +++ b/kernel/linux/meson.build
> > > @@ -3,20 +3,45 @@
> > >
> > > subdirs = ['kni']
> > >
> > > +cross_args = []
> > > # if we are cross-compiling we need kernel_dir specified -if
> > > get_option('kernel_dir') == '' and meson.is_cross_build()
> > > - error('Need "kernel_dir" option for kmod compilation when cross-
> > compiling')
> > > +if meson.is_cross_build()
> > > + if get_option('kernel_dir') == ''
> > > + error('Need "kernel_dir" option for kmod compilation when
> > cross-compiling')
> > > + else
> > > + cross_compiler = find_program('c').path()
> > > + if cross_compiler.endswith('gcc')
> > > + cross_prefix = ''
> > > + # remove the 'gcc' suffix
> > > + # meson doesn't support removing elements from an
> > array
> > > + # nor does it support slicing, so do it on our own
> > > + foreach element : cross_compiler.split('-')
> > > + if element != 'gcc'
> > > + cross_prefix += '@0@-
> > '.format(element)
> > > + endif
> > > + endforeach
> > > + else
> > > + error('Unsupported cross compiler:
> > @0@'.format(cross_compiler))
> > > + endif
> >
> > Rather than splitting manually, might it be better to just define a new property in
> > the cross-file to hold the prefix?
>
> That would by one more unnecessary input, so I don't like that.
>
> > Alternatively, rather than meson looping, why
> > not just use "run_command" to use shell or python to do the job, e.g. [untested]
> >
> > run_command([py3, '-c',
> > 'print("-".join("' + cross_compiler + '".split("-")[:-1]))')
> >
> > run_command('bash', '-c',
> > 'echo ' + cross_compiler + ' | sed "s/gcc$//"')
> >
>
> Since there isn't a better way to do this in Meson, it makes sense to use an external tool.
> On top of that, this would save lines and wouldn't need as many code comments. I'll change it.
>
> > > + if host_machine.cpu_family() == 'aarch64'
> > > + cross_arch = 'arm64'
> > > + else
> > > + cross_arch = build_machine.cpu_family()
> > > + endif
> > > + cross_args = ['ARCH=@0@'.format(cross_arch),
> > > + 'CROSS_COMPILE=@0@'.format(cross_prefix)]
> > > + endif
> > > endif
> > >
> > > kernel_dir = get_option('kernel_dir') if kernel_dir == ''
> > > # use default path for native builds
> > > kernel_version = run_command('uname', '-r').stdout().strip()
> > > - kernel_dir = '/lib/modules/' + kernel_version
> > > + kernel_dir = '/lib/modules/' + kernel_version + '/build'
> > > endif
> >
> > The reason we don't keep the "build" off the kernel_dir is to ensure that the
> > kernel modules install to the correct place. With this change the modules will go
> > in "/lib/modules/<version>/build/extra/dpdk", rather than
> > "/lib/modules/<version>/extra/dpdk".
> >
>
> Ah, I see. The modules will be installed during meson install. This should also be changed, then, as we always want to install them to '/lib/modules/<version>' (not necessarily to 'kernel_dir', as the user may change that) and only for native builds, right?
>
Well, we definitely want it for native builds, but I'd imagine it would be
useful for cross-builds too, no? 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?
/Bruce
> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Friday, January 29, 2021 2:51 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> dev@dpdk.org
> Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
>
> On Fri, Jan 29, 2021 at 12:33:06PM +0000, Juraj Linkeš wrote:
> >
> >
> > > -----Original Message-----
> > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > Sent: Friday, January 29, 2021 12:44 PM
> > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@dpdk.org
> > > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> > >
> > > On Fri, Jan 29, 2021 at 11:29:19AM +0100, Juraj Linkeš wrote:
> > > > The kni linux module is using a custom target for building, which
> > > > doesn't take into account any cross compilation arguments. The
> > > > arguments in question are ARCH and CROSS_COMPILE. Get those from
> > > > the cross file and pass them to the custom target.
> > > >
> > > > The user supplied path may not contain the 'build' directory, such
> > > > as when using cross-compiled headers, so only append that in the
> > > > default case (when no path is supplied in native builds) and use
> > > > the unmodified path from the user otherwise.
> > > >
> > > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > ---
> > > > kernel/linux/kni/meson.build | 4 ++--
> > > > kernel/linux/meson.build | 33 +++++++++++++++++++++++++++++----
> > > > 2 files changed, 31 insertions(+), 6 deletions(-)
> > > >
> > > > diff --git a/kernel/linux/kni/meson.build
> > > > b/kernel/linux/kni/meson.build index 07e0c9dae..0fbf52c93 100644
> > > > --- a/kernel/linux/kni/meson.build
> > > > +++ b/kernel/linux/kni/meson.build
> > > > @@ -13,7 +13,7 @@ kni_sources = files( custom_target('rte_kni',
> > > > input: kni_sources,
> > > > output: 'rte_kni.ko',
> > > > - command: ['make', '-j4', '-C', kernel_dir + '/build',
> > > > + command: ['make', '-j4', '-C', kernel_dir,
> > > > 'M=' + meson.current_build_dir(),
> > > > 'src=' + meson.current_source_dir(),
> > > > 'MODULE_CFLAGS=-include ' + meson.source_root() +
> > > > '/config/rte_config.h' + @@ -21,7 +21,7 @@ custom_target('rte_kni',
> > > > ' -I' + meson.source_root() + '/lib/librte_kni' +
> > > > ' -I' + meson.build_root() +
> > > > ' -I' + meson.current_source_dir(),
> > > > - 'modules'],
> > > > + 'modules'] + cross_args,
> > > > depends: kni_mkfile,
> > > > install: true,
> > > > install_dir: kernel_dir + '/extra/dpdk', diff --git
> > > > a/kernel/linux/meson.build b/kernel/linux/meson.build index
> > > > 5c864a465..57ed9bc48 100644
> > > > --- a/kernel/linux/meson.build
> > > > +++ b/kernel/linux/meson.build
> > > > @@ -3,20 +3,45 @@
> > > >
> > > > subdirs = ['kni']
> > > >
> > > > +cross_args = []
> > > > # if we are cross-compiling we need kernel_dir specified -if
> > > > get_option('kernel_dir') == '' and meson.is_cross_build()
> > > > - error('Need "kernel_dir" option for kmod compilation when cross-
> > > compiling')
> > > > +if meson.is_cross_build()
> > > > + if get_option('kernel_dir') == ''
> > > > + error('Need "kernel_dir" option for kmod compilation when
> > > cross-compiling')
> > > > + else
> > > > + cross_compiler = find_program('c').path()
> > > > + if cross_compiler.endswith('gcc')
> > > > + cross_prefix = ''
> > > > + # remove the 'gcc' suffix
> > > > + # meson doesn't support removing elements from an
> > > array
> > > > + # nor does it support slicing, so do it on our own
> > > > + foreach element : cross_compiler.split('-')
> > > > + if element != 'gcc'
> > > > + cross_prefix += '@0@-
> > > '.format(element)
> > > > + endif
> > > > + endforeach
> > > > + else
> > > > + error('Unsupported cross compiler:
> > > @0@'.format(cross_compiler))
> > > > + endif
> > >
> > > Rather than splitting manually, might it be better to just define a
> > > new property in the cross-file to hold the prefix?
> >
> > That would by one more unnecessary input, so I don't like that.
> >
> > > Alternatively, rather than meson looping, why not just use
> > > "run_command" to use shell or python to do the job, e.g. [untested]
> > >
> > > run_command([py3, '-c',
> > > 'print("-".join("' + cross_compiler + '".split("-")[:-1]))')
> > >
> > > run_command('bash', '-c',
> > > 'echo ' + cross_compiler + ' | sed "s/gcc$//"')
> > >
> >
> > Since there isn't a better way to do this in Meson, it makes sense to use an
> external tool.
> > On top of that, this would save lines and wouldn't need as many code
> comments. I'll change it.
> >
> > > > + if host_machine.cpu_family() == 'aarch64'
> > > > + cross_arch = 'arm64'
> > > > + else
> > > > + cross_arch = build_machine.cpu_family()
> > > > + endif
> > > > + cross_args = ['ARCH=@0@'.format(cross_arch),
> > > > + 'CROSS_COMPILE=@0@'.format(cross_prefix)]
> > > > + endif
> > > > endif
> > > >
> > > > kernel_dir = get_option('kernel_dir') if kernel_dir == ''
> > > > # use default path for native builds
> > > > kernel_version = run_command('uname', '-r').stdout().strip()
> > > > - kernel_dir = '/lib/modules/' + kernel_version
> > > > + kernel_dir = '/lib/modules/' + kernel_version + '/build'
> > > > endif
> > >
> > > The reason we don't keep the "build" off the kernel_dir is to ensure
> > > that the kernel modules install to the correct place. With this
> > > change the modules will go in
> > > "/lib/modules/<version>/build/extra/dpdk", rather than
> "/lib/modules/<version>/extra/dpdk".
> > >
> >
> > Ah, I see. The modules will be installed during meson install. This should also
> be changed, then, as we always want to install them to '/lib/modules/<version>'
> (not necessarily to 'kernel_dir', as the user may change that) and only for native
> builds, right?
> >
> Well, we definitely want it for native builds, but I'd imagine it would be useful for
> cross-builds too, no?
I guess it would be useful for setups with shared storage. Did you have something else in mind?
> 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.
A note: all this works just for gcc. Should I also add support for clang?
> /Bruce
On Fri, Jan 29, 2021 at 02:36:58PM +0000, Juraj Linkeš wrote:
>
>
> > -----Original Message-----
> > From: Bruce Richardson <bruce.richardson@intel.com>
> > Sent: Friday, January 29, 2021 2:51 PM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> > hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> > dev@dpdk.org
> > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> >
> > On Fri, Jan 29, 2021 at 12:33:06PM +0000, Juraj Linkeš wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > > Sent: Friday, January 29, 2021 12:44 PM
> > > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@dpdk.org
> > > > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> > > >
> > > > On Fri, Jan 29, 2021 at 11:29:19AM +0100, Juraj Linkeš wrote:
> > > > > The kni linux module is using a custom target for building, which
> > > > > doesn't take into account any cross compilation arguments. The
> > > > > arguments in question are ARCH and CROSS_COMPILE. Get those from
> > > > > the cross file and pass them to the custom target.
> > > > >
> > > > > The user supplied path may not contain the 'build' directory, such
> > > > > as when using cross-compiled headers, so only append that in the
> > > > > default case (when no path is supplied in native builds) and use
> > > > > the unmodified path from the user otherwise.
> > > > >
> > > > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > > ---
> > > > > kernel/linux/kni/meson.build | 4 ++--
> > > > > kernel/linux/meson.build | 33 +++++++++++++++++++++++++++++----
> > > > > 2 files changed, 31 insertions(+), 6 deletions(-)
> > > > >
> > > > > diff --git a/kernel/linux/kni/meson.build
> > > > > b/kernel/linux/kni/meson.build index 07e0c9dae..0fbf52c93 100644
> > > > > --- a/kernel/linux/kni/meson.build
> > > > > +++ b/kernel/linux/kni/meson.build
> > > > > @@ -13,7 +13,7 @@ kni_sources = files( custom_target('rte_kni',
> > > > > input: kni_sources,
> > > > > output: 'rte_kni.ko',
> > > > > - command: ['make', '-j4', '-C', kernel_dir + '/build',
> > > > > + command: ['make', '-j4', '-C', kernel_dir,
> > > > > 'M=' + meson.current_build_dir(),
> > > > > 'src=' + meson.current_source_dir(),
> > > > > 'MODULE_CFLAGS=-include ' + meson.source_root() +
> > > > > '/config/rte_config.h' + @@ -21,7 +21,7 @@ custom_target('rte_kni',
> > > > > ' -I' + meson.source_root() + '/lib/librte_kni' +
> > > > > ' -I' + meson.build_root() +
> > > > > ' -I' + meson.current_source_dir(),
> > > > > - 'modules'],
> > > > > + 'modules'] + cross_args,
> > > > > depends: kni_mkfile,
> > > > > install: true,
> > > > > install_dir: kernel_dir + '/extra/dpdk', diff --git
> > > > > a/kernel/linux/meson.build b/kernel/linux/meson.build index
> > > > > 5c864a465..57ed9bc48 100644
> > > > > --- a/kernel/linux/meson.build
> > > > > +++ b/kernel/linux/meson.build
> > > > > @@ -3,20 +3,45 @@
> > > > >
> > > > > subdirs = ['kni']
> > > > >
> > > > > +cross_args = []
> > > > > # if we are cross-compiling we need kernel_dir specified -if
> > > > > get_option('kernel_dir') == '' and meson.is_cross_build()
> > > > > - error('Need "kernel_dir" option for kmod compilation when cross-
> > > > compiling')
> > > > > +if meson.is_cross_build()
> > > > > + if get_option('kernel_dir') == ''
> > > > > + error('Need "kernel_dir" option for kmod compilation when
> > > > cross-compiling')
> > > > > + else
> > > > > + cross_compiler = find_program('c').path()
> > > > > + if cross_compiler.endswith('gcc')
> > > > > + cross_prefix = ''
> > > > > + # remove the 'gcc' suffix
> > > > > + # meson doesn't support removing elements from an
> > > > array
> > > > > + # nor does it support slicing, so do it on our own
> > > > > + foreach element : cross_compiler.split('-')
> > > > > + if element != 'gcc'
> > > > > + cross_prefix += '@0@-
> > > > '.format(element)
> > > > > + endif
> > > > > + endforeach
> > > > > + else
> > > > > + error('Unsupported cross compiler:
> > > > @0@'.format(cross_compiler))
> > > > > + endif
> > > >
> > > > Rather than splitting manually, might it be better to just define a
> > > > new property in the cross-file to hold the prefix?
> > >
> > > That would by one more unnecessary input, so I don't like that.
> > >
> > > > Alternatively, rather than meson looping, why not just use
> > > > "run_command" to use shell or python to do the job, e.g. [untested]
> > > >
> > > > run_command([py3, '-c',
> > > > 'print("-".join("' + cross_compiler + '".split("-")[:-1]))')
> > > >
> > > > run_command('bash', '-c',
> > > > 'echo ' + cross_compiler + ' | sed "s/gcc$//"')
> > > >
> > >
> > > Since there isn't a better way to do this in Meson, it makes sense to use an
> > external tool.
> > > On top of that, this would save lines and wouldn't need as many code
> > comments. I'll change it.
> > >
> > > > > + if host_machine.cpu_family() == 'aarch64'
> > > > > + cross_arch = 'arm64'
> > > > > + else
> > > > > + cross_arch = build_machine.cpu_family()
> > > > > + endif
> > > > > + cross_args = ['ARCH=@0@'.format(cross_arch),
> > > > > + 'CROSS_COMPILE=@0@'.format(cross_prefix)]
> > > > > + endif
> > > > > endif
> > > > >
> > > > > kernel_dir = get_option('kernel_dir') if kernel_dir == ''
> > > > > # use default path for native builds
> > > > > kernel_version = run_command('uname', '-r').stdout().strip()
> > > > > - kernel_dir = '/lib/modules/' + kernel_version
> > > > > + kernel_dir = '/lib/modules/' + kernel_version + '/build'
> > > > > endif
> > > >
> > > > The reason we don't keep the "build" off the kernel_dir is to ensure
> > > > that the kernel modules install to the correct place. With this
> > > > change the modules will go in
> > > > "/lib/modules/<version>/build/extra/dpdk", rather than
> > "/lib/modules/<version>/extra/dpdk".
> > > >
> > >
> > > Ah, I see. The modules will be installed during meson install. This should also
> > be changed, then, as we always want to install them to '/lib/modules/<version>'
> > (not necessarily to 'kernel_dir', as the user may change that) and only for native
> > builds, right?
> > >
> > Well, we definitely want it for native builds, but I'd imagine it would be useful for
> > cross-builds too, no?
>
> I guess it would be useful for setups with shared storage. Did you have something else in mind?
>
> > 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?
> A note: all this works just for gcc. Should I also add support for clang?
>
If possible, that would be great.
/Bruce
> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Friday, January 29, 2021 3:42 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> dev@dpdk.org
> Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
>
> On Fri, Jan 29, 2021 at 02:36:58PM +0000, Juraj Linkeš wrote:
> >
> >
> > > -----Original Message-----
> > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > Sent: Friday, January 29, 2021 2:51 PM
> > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@dpdk.org
> > > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> > >
> > > On Fri, Jan 29, 2021 at 12:33:06PM +0000, Juraj Linkeš wrote:
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > > > Sent: Friday, January 29, 2021 12:44 PM
> > > > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@dpdk.org
> > > > > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation
> > > > > support
> > > > >
> > > > > On Fri, Jan 29, 2021 at 11:29:19AM +0100, Juraj Linkeš wrote:
> > > > > > The kni linux module is using a custom target for building,
> > > > > > which doesn't take into account any cross compilation
> > > > > > arguments. The arguments in question are ARCH and
> > > > > > CROSS_COMPILE. Get those from the cross file and pass them to the
> custom target.
> > > > > >
> > > > > > The user supplied path may not contain the 'build' directory,
> > > > > > such as when using cross-compiled headers, so only append that
> > > > > > in the default case (when no path is supplied in native
> > > > > > builds) and use the unmodified path from the user otherwise.
> > > > > >
> > > > > > Signed-off-by: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > > > ---
> > > > > > kernel/linux/kni/meson.build | 4 ++--
> > > > > > kernel/linux/meson.build | 33 +++++++++++++++++++++++++++++---
> -
> > > > > > 2 files changed, 31 insertions(+), 6 deletions(-)
> > > > > >
> > > > > > diff --git a/kernel/linux/kni/meson.build
> > > > > > b/kernel/linux/kni/meson.build index 07e0c9dae..0fbf52c93
> > > > > > 100644
> > > > > > --- a/kernel/linux/kni/meson.build
> > > > > > +++ b/kernel/linux/kni/meson.build
> > > > > > @@ -13,7 +13,7 @@ kni_sources = files( custom_target('rte_kni',
> > > > > > input: kni_sources,
> > > > > > output: 'rte_kni.ko',
> > > > > > - command: ['make', '-j4', '-C', kernel_dir + '/build',
> > > > > > + command: ['make', '-j4', '-C', kernel_dir,
> > > > > > 'M=' + meson.current_build_dir(),
> > > > > > 'src=' + meson.current_source_dir(),
> > > > > > 'MODULE_CFLAGS=-include ' + meson.source_root() +
> > > > > > '/config/rte_config.h' + @@ -21,7 +21,7 @@ custom_target('rte_kni',
> > > > > > ' -I' + meson.source_root() + '/lib/librte_kni' +
> > > > > > ' -I' + meson.build_root() +
> > > > > > ' -I' + meson.current_source_dir(),
> > > > > > - 'modules'],
> > > > > > + 'modules'] + cross_args,
> > > > > > depends: kni_mkfile,
> > > > > > install: true,
> > > > > > install_dir: kernel_dir + '/extra/dpdk', diff --git
> > > > > > a/kernel/linux/meson.build b/kernel/linux/meson.build index
> > > > > > 5c864a465..57ed9bc48 100644
> > > > > > --- a/kernel/linux/meson.build
> > > > > > +++ b/kernel/linux/meson.build
> > > > > > @@ -3,20 +3,45 @@
> > > > > >
> > > > > > subdirs = ['kni']
> > > > > >
> > > > > > +cross_args = []
> > > > > > # if we are cross-compiling we need kernel_dir specified -if
> > > > > > get_option('kernel_dir') == '' and meson.is_cross_build()
> > > > > > - error('Need "kernel_dir" option for kmod compilation when
> cross-
> > > > > compiling')
> > > > > > +if meson.is_cross_build()
> > > > > > + if get_option('kernel_dir') == ''
> > > > > > + error('Need "kernel_dir" option for kmod compilation
> when
> > > > > cross-compiling')
> > > > > > + else
> > > > > > + cross_compiler = find_program('c').path()
> > > > > > + if cross_compiler.endswith('gcc')
> > > > > > + cross_prefix = ''
> > > > > > + # remove the 'gcc' suffix
> > > > > > + # meson doesn't support removing elements
> from an
> > > > > array
> > > > > > + # nor does it support slicing, so do it on our own
> > > > > > + foreach element : cross_compiler.split('-')
> > > > > > + if element != 'gcc'
> > > > > > + cross_prefix += '@0@-
> > > > > '.format(element)
> > > > > > + endif
> > > > > > + endforeach
> > > > > > + else
> > > > > > + error('Unsupported cross compiler:
> > > > > @0@'.format(cross_compiler))
> > > > > > + endif
> > > > >
> > > > > Rather than splitting manually, might it be better to just
> > > > > define a new property in the cross-file to hold the prefix?
> > > >
> > > > That would by one more unnecessary input, so I don't like that.
> > > >
> > > > > Alternatively, rather than meson looping, why not just use
> > > > > "run_command" to use shell or python to do the job, e.g.
> > > > > [untested]
> > > > >
> > > > > run_command([py3, '-c',
> > > > > 'print("-".join("' + cross_compiler + '".split("-")[:-1]))')
> > > > >
> > > > > run_command('bash', '-c',
> > > > > 'echo ' + cross_compiler + ' | sed "s/gcc$//"')
> > > > >
> > > >
> > > > Since there isn't a better way to do this in Meson, it makes sense
> > > > to use an
> > > external tool.
> > > > On top of that, this would save lines and wouldn't need as many
> > > > code
> > > comments. I'll change it.
> > > >
> > > > > > + if host_machine.cpu_family() == 'aarch64'
> > > > > > + cross_arch = 'arm64'
> > > > > > + else
> > > > > > + cross_arch = build_machine.cpu_family()
> > > > > > + endif
> > > > > > + cross_args = ['ARCH=@0@'.format(cross_arch),
> > > > > > + 'CROSS_COMPILE=@0@'.format(cross_prefix)]
> > > > > > + endif
> > > > > > endif
> > > > > >
> > > > > > kernel_dir = get_option('kernel_dir') if kernel_dir == ''
> > > > > > # use default path for native builds
> > > > > > kernel_version = run_command('uname', '-r').stdout().strip()
> > > > > > - kernel_dir = '/lib/modules/' + kernel_version
> > > > > > + kernel_dir = '/lib/modules/' + kernel_version + '/build'
> > > > > > endif
> > > > >
> > > > > The reason we don't keep the "build" off the kernel_dir is to
> > > > > ensure that the kernel modules install to the correct place.
> > > > > With this change the modules will go in
> > > > > "/lib/modules/<version>/build/extra/dpdk", rather than
> > > "/lib/modules/<version>/extra/dpdk".
> > > > >
> > > >
> > > > Ah, I see. The modules will be installed during meson install.
> > > > This should also
> > > be changed, then, as we always want to install them to
> '/lib/modules/<version>'
> > > (not necessarily to 'kernel_dir', as the user may change that) and
> > > only for native builds, right?
> > > >
> > > Well, we definitely want it for native builds, but I'd imagine it
> > > would be useful for cross-builds too, no?
> >
> > I guess it would be useful for setups with shared storage. Did you have
> something else in mind?
> >
> > > 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.
> > A note: all this works just for gcc. Should I also add support for clang?
> >
> If possible, that would be great.
>
Ok, I'll look into it.
> /Bruce
On Fri, Jan 29, 2021 at 02:47:57PM +0000, Juraj Linkeš wrote:
>
>
> > -----Original Message-----
> > From: Bruce Richardson <bruce.richardson@intel.com>
> > Sent: Friday, January 29, 2021 3:42 PM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> > hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> > dev@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?
> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Friday, January 29, 2021 4:01 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> dev@dpdk.org
> Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
>
> On Fri, Jan 29, 2021 at 02:47:57PM +0000, Juraj Linkeš wrote:
> >
> >
> > > -----Original Message-----
> > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > Sent: Friday, January 29, 2021 3:42 PM
> > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@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?
Assuming that we want to install cross modules, then yes, although it's incomplete. There's also the scenario when a user would use different kernel_dir than the default for native builds. I don't know why anyone would do that, but it is a theoretical possibility :-)
On Fri, Jan 29, 2021 at 03:17:02PM +0000, Juraj Linkeš wrote:
>
>
> > -----Original Message-----
> > From: Bruce Richardson <bruce.richardson@intel.com>
> > Sent: Friday, January 29, 2021 4:01 PM
> > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> > hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> > dev@dpdk.org
> > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> >
> > On Fri, Jan 29, 2021 at 02:47:57PM +0000, Juraj Linkeš wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > > Sent: Friday, January 29, 2021 3:42 PM
> > > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@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?
>
> Assuming that we want to install cross modules, then yes, although it's incomplete. There's also the scenario when a user would use different kernel_dir than the default for native builds. I don't know why anyone would do that, but it is a theoretical possibility :-)
In the cross-compile install case, is the prefix /usr/aarch64-linux-gnu/
coming from a DESTDIR environment variable? If it is, then we could just
use the kernel_dir option for the build path, and always install to
/lib/modules/<ver>/... allowing any cross-compiler relocation to take care
of the rest.
> -----Original Message-----
> From: Bruce Richardson <bruce.richardson@intel.com>
> Sent: Friday, January 29, 2021 4:40 PM
> To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com; jerinjacobk@gmail.com;
> hemant.agrawal@nxp.com; ferruh.yigit@intel.com; aboyer@pensando.io;
> dev@dpdk.org
> Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
>
> On Fri, Jan 29, 2021 at 03:17:02PM +0000, Juraj Linkeš wrote:
> >
> >
> > > -----Original Message-----
> > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > Sent: Friday, January 29, 2021 4:01 PM
> > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@dpdk.org
> > > Subject: Re: [RFC PATCH v1] build: kni gcc cross-compilation support
> > >
> > > On Fri, Jan 29, 2021 at 02:47:57PM +0000, Juraj Linkeš wrote:
> > > >
> > > >
> > > > > -----Original Message-----
> > > > > From: Bruce Richardson <bruce.richardson@intel.com>
> > > > > Sent: Friday, January 29, 2021 3:42 PM
> > > > > To: Juraj Linkeš <juraj.linkes@pantheon.tech>
> > > > > Cc: thomas@monjalon.net; Ruifeng.Wang@arm.com;
> > > > > jerinjacobk@gmail.com; hemant.agrawal@nxp.com;
> > > > > ferruh.yigit@intel.com; aboyer@pensando.io; dev@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?
> >
> > Assuming that we want to install cross modules, then yes, although
> > it's incomplete. There's also the scenario when a user would use
> > different kernel_dir than the default for native builds. I don't know
> > why anyone would do that, but it is a theoretical possibility :-)
>
> In the cross-compile install case, is the prefix /usr/aarch64-linux-gnu/ coming
> from a DESTDIR environment variable? If it is, then we could just use the
> kernel_dir option for the build path, and always install to /lib/modules/<ver>/...
> allowing any cross-compiler relocation to take care of the rest.
It's not coming from anywhere. What I meant is that an ubuntu package such as 'libatomic1-arm64-cross' installs its headers/libs under /usr/aarch64-linux-gnu/.
@@ -13,7 +13,7 @@ kni_sources = files(
custom_target('rte_kni',
input: kni_sources,
output: 'rte_kni.ko',
- command: ['make', '-j4', '-C', kernel_dir + '/build',
+ command: ['make', '-j4', '-C', kernel_dir,
'M=' + meson.current_build_dir(),
'src=' + meson.current_source_dir(),
'MODULE_CFLAGS=-include ' + meson.source_root() + '/config/rte_config.h' +
@@ -21,7 +21,7 @@ custom_target('rte_kni',
' -I' + meson.source_root() + '/lib/librte_kni' +
' -I' + meson.build_root() +
' -I' + meson.current_source_dir(),
- 'modules'],
+ 'modules'] + cross_args,
depends: kni_mkfile,
install: true,
install_dir: kernel_dir + '/extra/dpdk',
@@ -3,20 +3,45 @@
subdirs = ['kni']
+cross_args = []
# if we are cross-compiling we need kernel_dir specified
-if get_option('kernel_dir') == '' and meson.is_cross_build()
- error('Need "kernel_dir" option for kmod compilation when cross-compiling')
+if meson.is_cross_build()
+ if get_option('kernel_dir') == ''
+ error('Need "kernel_dir" option for kmod compilation when cross-compiling')
+ else
+ cross_compiler = find_program('c').path()
+ if cross_compiler.endswith('gcc')
+ cross_prefix = ''
+ # remove the 'gcc' suffix
+ # meson doesn't support removing elements from an array
+ # nor does it support slicing, so do it on our own
+ foreach element : cross_compiler.split('-')
+ if element != 'gcc'
+ cross_prefix += '@0@-'.format(element)
+ endif
+ endforeach
+ else
+ error('Unsupported cross compiler: @0@'.format(cross_compiler))
+ endif
+ if host_machine.cpu_family() == 'aarch64'
+ cross_arch = 'arm64'
+ else
+ cross_arch = build_machine.cpu_family()
+ endif
+ cross_args = ['ARCH=@0@'.format(cross_arch),
+ 'CROSS_COMPILE=@0@'.format(cross_prefix)]
+ endif
endif
kernel_dir = get_option('kernel_dir')
if kernel_dir == ''
# use default path for native builds
kernel_version = run_command('uname', '-r').stdout().strip()
- kernel_dir = '/lib/modules/' + kernel_version
+ kernel_dir = '/lib/modules/' + kernel_version + '/build'
endif
# test running make in kernel directory, using "make kernelversion"
-make_returncode = run_command('make', '-sC', kernel_dir + '/build',
+make_returncode = run_command('make', '-sC', kernel_dir,
'kernelversion').returncode()
if make_returncode != 0
error('Cannot compile kernel modules as requested - are kernel headers installed?')