initial buildroot for linux 5.15

package/libbpf/libbpf.mk

@@ -0,0 +1,40 @@
+################################################################################
+#
+# libbpf
+#
+################################################################################
+
+LIBBPF_VERSION = 0.4.0
+LIBBPF_SITE = $(call github,libbpf,libbpf,v$(LIBBPF_VERSION))
+LIBBPF_LICENSE = GPL-2.0, LGPL-2.1, BSD-2-Clause
+LIBBPF_LICENSE_FILES = LICENSE LICENSE.BSD-2-Clause LICENSE.LGPL-2.1
+LIBBPF_DEPENDENCIES = host-bison host-flex host-pkgconf elfutils zlib
+LIBBPF_INSTALL_STAGING = YES
+
+define LIBBPF_BUILD_CMDS
+	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) \
+		-C $(@D)/src
+endef
+
+# bpf/bpf.h installed by libbpf uses bpf_iter_link_info that was added since
+# kernel 5.9, so we need to update some uapi headers in STAGING_DIR if the
+# toolchain is build with linux-headers < 5.9.
+# Otherwise bpf/bpf.h is broken due to out of date linux/bpf.h installed by the
+# toolchain.
+# https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=a5cbe05a6673b85bed2a63ffcfea6a96c6410cff
+ifeq ($(BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_9),)
+LIBBPF_UPDATE_UAPI_HEADERS = install_uapi_headers
+endif
+
+define LIBBPF_INSTALL_STAGING_CMDS
+	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) \
+		-C $(@D)/src install $(LIBBPF_UPDATE_UAPI_HEADERS) \
+		DESTDIR=$(STAGING_DIR)
+endef
+
+define LIBBPF_INSTALL_TARGET_CMDS
+	$(TARGET_MAKE_ENV) $(TARGET_CONFIGURE_OPTS) $(MAKE) \
+		-C $(@D)/src install DESTDIR=$(TARGET_DIR)
+endef
+
+$(eval $(generic-package))