--- zzzz-none-000/linux-3.10.107/Documentation/filesystems/ramfs-rootfs-initramfs.txt	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/Documentation/filesystems/ramfs-rootfs-initramfs.txt	2021-02-04 17:41:59.000000000 +0000
@@ -79,6 +79,10 @@
 Most systems just mount another filesystem over rootfs and ignore it.  The
 amount of space an empty instance of ramfs takes up is tiny.
 
+If CONFIG_TMPFS is enabled, rootfs will use tmpfs instead of ramfs by
+default.  To force ramfs, add "rootfstype=ramfs" to the kernel command
+line.
+
 What is initramfs?
 ------------------