Running islet with --normal-world=linux-net breaks network configuration on the host

[Havner]

Following the following readme:
https://github.com/Samsung/islet/blob/main/doc/network.md

Running fvp with the following command breaks network configuration on the host effectively cutting it off the internet.

./scripts/fvp-cca --normal-world=linux-net --realm=linux --rmm=tf-rmm

Which is a serious issue when working remotely.

[Havner]

This line is the culrpit:

sudo ip route add default via ${gateway} dev armbr0

I'm not sure what the intention was but shouldn't be required in any way to change/overwrite/add default route on the host for the network to work in the fvp/realm.

[Havner]

Also this line will not work when run from non privileged account:

sudo echo 1 >/proc/sys/net/ipv4/ip_forward

I recommend tee(1)

[jinbpark]

As you said, creating a tab device on the host side would be enough to enable network between Host<->FVP_Host<->Realm. (I don't remember what my intention was...) If the script you modified works, could you make a PR for that change? I can test it on our side and merge it.

[Havner]

#243