-IMAGE_BOOT_FILES_append = " ${@bb.utils.contains('AGL_XEN_WANTED','1', 'xen-${MACHINE}', '',d)}"
+IMAGE_BOOT_FILES:append = " ${@bb.utils.contains('AGL_XEN_WANTED','1', 'xen-${MACHINE}', '',d)}"
+
+PREFERRED_VERSION_u-boot = "2021.07"
+PREFERRED_VERSION_u-boot-tools = "2021.07"
+UBOOT_MACHINE:rpi = "rpi_arm64_config"