Zyxel "firmware" format is just… a FIT with some metadata on the models.
This FIT is like this:
--------------------------
uImage FIT header
--------------------------
Linux kernel
--------------------------
FDT DTB
--------------------------
Padding so that
this makes
8192kb [1]
--------------------------
UBI volume
as a root filesystem
--------------------------
We just reproduce this in a very brutal and naive way.
In the future, this seems worth to generalize and modularize this idea
so that zyxel-nwa-fit is just an instance of a more general output.
[1]: https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=target/linux/ramips/image/mt7621.mk;h=ab1b829ba0086cb9fc9ca8cbbf3cbc14735034d6;hb=refs/heads/main#l3097
Signed-off-by: Raito Bezarius <masterancpp@gmail.com>
63007859c2