build: use numeric uid/gid on cpio calls

There are systems that don't have the 'root' group, so don't rely on host
specific user/group names

Signed-off-by: Felix Fietkau <[email protected]>

include/image.mk

@@ -301,7 +301,7 @@ endif
 
 ifdef CONFIG_TARGET_ROOTFS_CPIOGZ
   define Image/Build/cpiogz
-	( cd $(TARGET_DIR); find . | $(STAGING_DIR_HOST)/bin/cpio -o -H newc -R root:root | gzip -9n >$(BIN_DIR)/$(IMG_ROOTFS).cpio.gz )
+	( cd $(TARGET_DIR); find . | $(STAGING_DIR_HOST)/bin/cpio -o -H newc -R 0:0 | gzip -9n >$(BIN_DIR)/$(IMG_ROOTFS).cpio.gz )
   endef
 endif
 

include/kernel-defaults.mk

@@ -163,7 +163,7 @@ ifeq ($(CONFIG_TARGET_ROOTFS_INITRAMFS_SEPARATE),y)
 ifeq ($(CONFIG_EXTERNAL_CPIO),y)
 	$(CP) $(CONFIG_EXTERNAL_CPIO) $(KERNEL_BUILD_DIR)/initrd.cpio
 else
-	( cd $(TARGET_DIR); find . | $(STAGING_DIR_HOST)/bin/cpio -o -H newc -R root:root > $(KERNEL_BUILD_DIR)/initrd.cpio )
+	( cd $(TARGET_DIR); find . | $(STAGING_DIR_HOST)/bin/cpio -o -H newc -R 0:0 > $(KERNEL_BUILD_DIR)/initrd.cpio )
 endif
 	$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_BZIP2),bzip2 -9 -c < $(KERNEL_BUILD_DIR)/initrd.cpio > $(KERNEL_BUILD_DIR)/initrd.cpio.bzip2)
 	$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_GZIP),gzip -f -S .gzip -9n $(KERNEL_BUILD_DIR)/initrd.cpio)