[PATCH fstools] libfstools: support custom executable validating overlay

[Rafał Miłecki]

On 4.01.2022 23:46, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal at milecki.pl>
> 
> This results in calling /usr/libexec/overlay_verify which may either
> modify overlay (e.g. wipe it) or refuse it. It's needed by targets that
> need to validate that "rootfs_data" doesn't come from a previous
> firmware. They may provide a script that will wipe such /outdated/
> overlays.
> 
> Signed-off-by: Rafał Miłecki <rafal at milecki.pl>

I didn't get much feedback of Felix's ack and I wasn't sure if that is a
correct way and if it's worth adding another callback.

I've pushed 93259e8ca261 ("bcm4908: support "rootfs_data" on U-Boot
devices master") that works without this fstools change.