Re: [dpdk-dev] [PATCH v6] build: kni cross-compilation support

No, I am sorry, I have not tested it. I was able to remove rte_kni from our requirements so this is no longer a blocker for us.

-Andrew

On Mar 9, 2021, at 3:47 AM, Juraj Linkeš [off-list ref] wrote:

Hi Folks,

Does anyone have any comments? Is the patch ready? If so, please send acks or reviewed-by, thanks.

Andrew, did you get a chance to test the patch?

Juraj

quoted

-----Original Message-----
From: Juraj Linkeš <redacted>
Sent: Thursday, February 11, 2021 2:00 PM
To: bruce.richardson@intel.com; thomas@monjalon.net;
Ruifeng.Wang@arm.com; Honnappa.Nagarahalli@arm.com;
jerinjacobk@gmail.com; hemant.agrawal@nxp.com; ferruh.yigit@intel.com;
aboyer@pensando.io
Cc: dev@dpdk.org; Juraj Linkeš <redacted>
Subject: [PATCH v6] build: kni cross-compilation support

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, CROSS_COMPILE (for gcc, clang) and CC, LD (for clang). 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.
Also modify the install path accordingly.

Signed-off-by: Juraj Linkeš <redacted>
Reviewed-by: Bruce Richardson <redacted>
---
kernel/linux/kni/meson.build |  8 ++--
kernel/linux/meson.build     | 90 ++++++++++++++++++++++++++++++------
meson_options.txt            |  2 +-
3 files changed, 82 insertions(+), 18 deletions(-)

diff --git a/kernel/linux/kni/meson.build b/kernel/linux/kni/meson.build index

07e0c9dae7..46b71c7418 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_build_dir,
		'M=' + meson.current_build_dir(),
		'src=' + meson.current_source_dir(),
		'MODULE_CFLAGS=-include ' + meson.source_root() +
'/config/rte_config.h' + @@ -21,8 +21,8 @@ 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',
+	install: install,
+	install_dir: kernel_install_dir,
	build_by_default: get_option('enable_kmods')) diff --git
a/kernel/linux/meson.build b/kernel/linux/meson.build index
5c864a4653..7b15e0fd44 100644

--- a/kernel/linux/meson.build
+++ b/kernel/linux/meson.build

@@ -3,25 +3,89 @@

subdirs = ['kni']

-# 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')
-endif
+kernel_build_dir = get_option('kernel_dir') kernel_install_dir = ''
+install = not meson.is_cross_build()
+cross_args = []

-kernel_dir = get_option('kernel_dir')
-if kernel_dir == ''
-	# use default path for native builds
+if not meson.is_cross_build()
+	# native build
	kernel_version = run_command('uname', '-r').stdout().strip()
-	kernel_dir = '/lib/modules/' + kernel_version
+	kernel_install_dir = '/lib/modules/' + kernel_version + '/extra/dpdk'
+	if kernel_build_dir == ''
+		# use default path for native builds
+		kernel_build_dir = '/lib/modules/' + kernel_version + '/build'
+	endif
+
+	# test running make in kernel directory, using "make kernelversion"
+	make_returncode = run_command('make', '-sC', kernel_build_dir,
+			'kernelversion').returncode()
+	if make_returncode != 0
+		# backwards compatibility:
+		# the headers could still be in the 'build' subdir
+		if not kernel_build_dir.endswith('build') and not
kernel_build_dir.endswith('build/')
+			kernel_build_dir = join_paths(kernel_build_dir, 'build')
+			make_returncode = run_command('make', '-sC',
kernel_build_dir,
+					'kernelversion').returncode()
+		endif
+	endif
+
+	if make_returncode != 0
+		error('Cannot compile kernel modules as requested - are kernel
headers installed?')
+	endif
+
+	# DO ACTUAL MODULE BUILDING
+	foreach d:subdirs
+		subdir(d)
+	endforeach
+
+	subdir_done()
endif

-# test running make in kernel directory, using "make kernelversion"
-make_returncode = run_command('make', '-sC', kernel_dir + '/build',
-		'kernelversion').returncode()
-if make_returncode != 0
-	error('Cannot compile kernel modules as requested - are kernel headers
installed?')
+# cross build
+# if we are cross-compiling we need kernel_build_dir specified if
+kernel_build_dir == ''
+	error('Need "kernel_dir" option for kmod compilation when
+cross-compiling') endif cross_compiler = find_program('c').path() if
+cross_compiler.endswith('gcc')
+	cross_prefix = run_command([py3, '-c', 'print("' + cross_compiler +
+'"[:-3])']).stdout().strip() elif cross_compiler.endswith('clang')
+	cross_prefix = ''
+	found_target = false
+	# search for '-target' and use the arg that follows
+	# (i.e. the value of '-target') as cross_prefix
+	foreach cross_c_arg : meson.get_cross_property('c_args')
+		if found_target and cross_prefix == ''
+			cross_prefix = cross_c_arg
+		endif
+		if cross_c_arg == '-target'
+			found_target = true
+		endif
+	endforeach
+	if cross_prefix == ''
+		error('Didn\'t find -target and its value in' +
+		      ' c_args in input cross-file.')
+	endif
+	linker = 'lld'
+	foreach cross_c_link_arg : meson.get_cross_property('c_link_args')
+		if cross_c_link_arg.startswith('-fuse-ld')
+			linker = cross_c_link_arg.split('=')[1]
+		endif
+	endforeach
+	cross_args += ['CC=@0@'.format(cross_compiler),
+'LD=ld.@0@'.format(linker)] else
+	error('Unsupported cross compiler: @0@'.format(cross_compiler))
endif

+cross_arch = host_machine.cpu_family()
+if host_machine.cpu_family() == 'aarch64'
+	cross_arch = 'arm64'
+endif
+
+cross_args += ['ARCH=@0@'.format(cross_arch),
+	'CROSS_COMPILE=@0@'.format(cross_prefix)]
+
# DO ACTUAL MODULE BUILDING
foreach d:subdirs
	subdir(d)

diff --git a/meson_options.txt b/meson_options.txt index

6eff62e47d..3b8c5d316d 100644

--- a/meson_options.txt
+++ b/meson_options.txt

@@ -19,7 +19,7 @@ option('ibverbs_link', type: 'combo', choices : ['static',

'shared', 'dlopen'],  option('include_subdir_arch', type: 'string', value: '',
	description: 'subdirectory where to install arch-dependent headers')
option('kernel_dir', type: 'string', value: '',
-	description: 'Path to the kernel for building kernel modules. Headers
must be in $kernel_dir/build. Modules will be installed in
$DEST_DIR/$kernel_dir/extra/dpdk.')
+	description: 'Path to the kernel for building kernel modules. Headers
+must be in $kernel_dir or $kernel_dir/build. Modules will be installed
+in /lib/modules.')
option('machine', type: 'string', value: 'native',
	description: 'set the target machine type')  option('max_ethports', type:
'integer', value: 32,
--
2.20.1