> > 3. Allow the UML to use a tty directly, instead of a pty (thus
> > bypassing the need for an additional program to connect two ttys)
>So, you'd hook it up to an unused console on the host, switch to that
>and you'd see the UML login?
I didn't think of that, but it's a great idea. I was thinking about having
one UML use a pty, and a second UML use the corresponding tty - that way it
would appear that they are connected via a serial line.
> > 4. Allow the virtual serial line to be a TCP connection (i.e. allow
> > the UML to function as a virtual "terminal server"). This would be
> > very useful, since you could then use a remote server to connect a
> > UML to the network, without requiring root privileges on the server
> > actually running the UML.
>This would be done by running PPP on both sides of the connection, I take
>That's an interesting idea.
> > 5. Integrate the PPP code in a similar manner to the SLIP code (so
> > that from inside the UML the ppp device would appear to be a regular
> > network device).
>I looked at ppp before deciding to use slip. I think the reason was that I
>couldn't see how to get access to a ppp device from userspace, although I
>guess that pppd manages it fine.
I don't understand exactly why you need to access the ppp device from
userspace. What I'm thinking about is something like this: On the host side
of the connection, you'd get a tty to which you can connect pppd (i.e. The
exact same thing you get when you actually run pppd inside the UML on the
virtual serial line). Since you're not actually creating an interface on the
host side, you don't need root permissions. On the UML side, you'll appear
to have an "eth0" device but it will actually be a "hidden" instance of
pppd, with a thin translating layer (to allow emulation of an actual
Another possibility is have the host half of the ppp connection be pptp or
PPPoE (AFAIK existing linux clients actually run pppd). This would allow you
to connect multiple UMLs in a virtual network using a remote pptp or PPPoE
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