build: support KNI cross-compilation

[dpdk.git] / kernel / linux / meson.build

diff --git a/kernel/linux/meson.build b/kernel/linux/meson.build
index 5c864a4..b434706 100644 (file)
--- 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
+               # backward 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)