FBSD 10.1 + serial access (broken?)

[Warren Block]

On Sat, 17 Jan 2015, Christian Weisgerber wrote:

> On 2015-01-15, Paul Macdonald <paul at ifdnrg.com> wrote:
>
>> Can anyone confirm working serial console access on 10.1,
>
> Works for me with a Soekris net5501.
>
> The one annoying problem I have with this setup is that the machine
> will not reboot if the console isn't hooked up to a terminal.
> Judging from the point where it continues when I plug in a cable,
> boot(8) appears to be stuck without DCD and/or DSR.

Can't those be tied together on the computer side to fake it?  (It's 
been years--intentionally--since I've wired up a serial cable, so the 
details might be a bit off.)