fixup! feat(extensions): add netboot extension for full TFTP+NFS boot

Author: iav

extensions/netboot/netboot.sh

@@ -48,6 +48,9 @@ function extension_prepare_config__netboot_defaults_and_validate() {
 	fi
 	declare -g NETBOOT_HOSTNAME="${NETBOOT_HOSTNAME:-}"
 	declare -g NETBOOT_CLIENT_MAC="${NETBOOT_CLIENT_MAC:-}"
+	# Declared unconditionally so later `[[ -n "${NETBOOT_CLIENT_MAC_NORMALIZED}" ]]`
+	# checks remain safe under `set -u` when no MAC is configured.
+	declare -g NETBOOT_CLIENT_MAC_NORMALIZED=""
 	declare -g NETBOOT_TFTP_PREFIX="${NETBOOT_TFTP_PREFIX:-armbian/${LINUXFAMILY}/${BOARD}/${BRANCH}-${RELEASE}}"
 
 	if [[ -n "${NETBOOT_HOSTNAME}" ]]; then
@@ -60,7 +63,7 @@ function extension_prepare_config__netboot_defaults_and_validate() {
 	fi
 
 	if [[ -n "${NETBOOT_CLIENT_MAC}" ]]; then
-		declare -g NETBOOT_CLIENT_MAC_NORMALIZED="${NETBOOT_CLIENT_MAC//:/-}"
+		NETBOOT_CLIENT_MAC_NORMALIZED="${NETBOOT_CLIENT_MAC//:/-}"
 		NETBOOT_CLIENT_MAC_NORMALIZED="${NETBOOT_CLIENT_MAC_NORMALIZED,,}"
 		if [[ ! "${NETBOOT_CLIENT_MAC_NORMALIZED}" =~ ^[0-9a-f]{2}-[0-9a-f]{2}-[0-9a-f]{2}-[0-9a-f]{2}-[0-9a-f]{2}-[0-9a-f]{2}$ ]]; then
 			exit_with_error "${EXTENSION}: NETBOOT_CLIENT_MAC must look like aa:bb:cc:dd:ee:ff (got '${NETBOOT_CLIENT_MAC}')"
@@ -84,6 +87,7 @@ function extension_prepare_config__netboot_defaults_and_validate() {
 
 # Ensure NFS-root client support is built into the kernel.
 function custom_kernel_config__netboot_enable_nfs_root() {
+	[[ "${ROOTFS_TYPE}" == "nfs-root" ]] || return 0
 	opts_y+=("ROOT_NFS" "NFS_FS" "NFS_V3" "IP_PNP" "IP_PNP_DHCP")
 }