--- /dev/null
+Upstream changed the default rootfs to tmpfs when none has been passed
+to the kernel - this doesn't fit our purposes, so change it back.
+
+Signed-off-by: Imre Kaloz <kaloz@openwrt.org>
+
+--- a/init/do_mounts.c
++++ b/init/do_mounts.c
+@@ -622,6 +622,7 @@ int __init init_rootfs(void)
+ if (err)
+ return err;
+
++#if 0
+ if (IS_ENABLED(CONFIG_TMPFS) && !saved_root_name[0] &&
+ (!root_fs_names || strstr(root_fs_names, "tmpfs"))) {
+ err = shmem_init();
+@@ -629,6 +630,9 @@ int __init init_rootfs(void)
+ } else {
+ err = init_ramfs_fs();
+ }
++#else
++ err = init_ramfs_fs();
++#endif
+
+ if (err)
+ unregister_filesystem(&rootfs_fs_type);