由于 KernelSU 已切换到 metamodule ，MKSU 后续版本将不再包含 magic mount 。作者无意维护 magic mount metamodule ，有需要可参考分支 old_mksu 的代码进行开发

for ultra legacy, atleast for 3.10+ I have a working overlayfs-4.1 backport.
this is the minimum overlayfs usable for nowadays. overlay stacking started around Linux 4.1.

theres also overlayfs-rc for 3.4
https://github.com/adilinden-oss/overlayfs-patches


for 3.0 we can use mini_fo
and I don't think anyone still uses 3.0 for reals anyway. I only keep one as a demo.

however, I do still have the source code for mini_fo.
The precursor of overlayfs.

https://github.com/backslashxx/mini_fo
mini_fo: mini fanout-overlay

mini_fo is a virtual kernel file system that can make read-only
file systems writable. This is done by redirecting modifying operations
to a writeable location called "storage directory", and leaving the
original data in the "base directory" untouched. When reading, the
file system merges the modifed and original data so that only the
newest versions will appear. This occurs transparently to the user,
who can access the data like on any other read-write file system.

Copyright (C) 2004, 2005 Markus Klotzbuecher <mk@creamnet.de>

I got it from the depths of openwrt sdk tarballs.
Literal tech archaeology.

this is 7a72's work

I only filled the installer script so it can be used

https://github.com/7a72/meta-magic_mount