initial buildroot for linux 5.15

toolchain/toolchain/toolchain.mk

@@ -0,0 +1,50 @@
+################################################################################
+#
+# toolchain
+#
+################################################################################
+
+ifeq ($(BR2_TOOLCHAIN_BUILDROOT),y)
+TOOLCHAIN_DEPENDENCIES += toolchain-buildroot
+else ifeq ($(BR2_TOOLCHAIN_EXTERNAL),y)
+TOOLCHAIN_DEPENDENCIES += toolchain-external
+endif
+
+TOOLCHAIN_ADD_TOOLCHAIN_DEPENDENCY = NO
+TOOLCHAIN_INSTALL_STAGING = YES
+
+# Apply a hack that Rick Felker suggested[1] to avoid conflicts between libc
+# headers and kernel headers. This is needed for kernel headers older than
+# 4.15. Kernel headers 4.15 and newer don't require __GLIBC__ to be defined.
+#
+# Augment the original suggestion with __USE_MISC since recent kernels
+# (older than 4.15) require this glibc internal macro. Also, as musl defines
+# IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO, add another macro to suppress
+# them in the kernel header, and avoid macro/enum conflict.
+#
+# Kernel version 3.12 introduced the libc-compat.h header.
+#
+# [1] http://www.openwall.com/lists/musl/2015/10/08/2
+ifeq ($(BR2_TOOLCHAIN_USES_MUSL)$(BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_12):$(BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_15),yy:)
+define TOOLCHAIN_MUSL_KERNEL_HEADERS_COMPATIBILITY_HACK
+	$(SED) 's/^#if defined(__GLIBC__)$$/#if 1/' \
+		$(STAGING_DIR)/usr/include/linux/libc-compat.h
+	$(SED) '1s/^/#define __USE_MISC\n/' \
+		$(STAGING_DIR)/usr/include/linux/libc-compat.h
+	$(SED) '1s/^/#define __UAPI_DEF_IF_NET_DEVICE_FLAGS_LOWER_UP_DORMANT_ECHO 0\n/' \
+		$(STAGING_DIR)/usr/include/linux/libc-compat.h
+endef
+TOOLCHAIN_POST_INSTALL_STAGING_HOOKS += TOOLCHAIN_MUSL_KERNEL_HEADERS_COMPATIBILITY_HACK
+endif
+
+# Install default nsswitch.conf file if the skeleton doesn't provide it
+ifeq ($(BR2_TOOLCHAIN_USES_GLIBC),y)
+define TOOLCHAIN_GLIBC_COPY_NSSWITCH_FILE
+	@if [ ! -f "$(TARGET_DIR)/etc/nsswitch.conf" ]; then \
+		$(INSTALL) -D -m 0644 package/glibc/nsswitch.conf $(TARGET_DIR)/etc/nsswitch.conf ; \
+	fi
+endef
+TOOLCHAIN_POST_INSTALL_TARGET_HOOKS += TOOLCHAIN_GLIBC_COPY_NSSWITCH_FILE
+endif
+
+$(eval $(virtual-package))