>> Copy/dev/ to/tmp/RFS/dev/
>
> so is the actual command:
> cp -r /dev/ /tmp/RFS/dev/
>
> If I try without the -r I get the error/warning message:
> cp: -r not specified; omitting directory /dev/
AFAIK nowadays `/dev` is normally stored in another filesyste,
dynamically populated. So you don't want to copy it to your
root filesystem.
Instead you want to "make it appear" there.
The way I do that, usually is with:
mount --bind /dev /tmp/RFS/dev
I usually use that same approach to populate the `/proc` and `/sys`
directories before doing the `chroot`.
= Stefan