boot0sio working for anyone?

Julian H. Stacey jhs at
Sat Feb 9 11:02:46 UTC 2008

"Daniel O'Connor" wrote:
> --nextPart1361955.8Fq3uESWdG
> Content-Type: text/plain;
>   charset="iso-8859-1"
> Content-Transfer-Encoding: quoted-printable
> Content-Disposition: inline
> On Sat, 9 Feb 2008, Ulrich Spoerlein wrote:
> > So, is boot0sio supposed to just work with a cheap USB->RS232 dongle
> > at the other end? I don't know how this paragraph from boot0cfg(8) is
> > affecting me.
> >
> >
> >      -b boot0
> >              Specify which `boot0' image to use.  The default is
> > /boot/boot0 which will use the video card as output, alternatively
> > /boot/boot0sio can be used for output to the COM1 port.  (Be aware
> > that nothing will be output to the COM1 port unless the modem signals
> > DSR and CTS are active.)
> If by "other end" you mean the PC that ISN'T using boot0sio then I think=20
> it would work fine.
> Even a really shitty RS232 dongle would get DSR & CTS right otherwise=20
> stuff like modems wouldn't work with it either..

Only if the program running on 2nd machine tells its USB dongle
to set DC conditions appropriately no guarantee of that, up to the human,
Ulrich in this case

>From Ulrich:
> And I'm not sure if this provides the
> necessary signals to boot0sio to start working.

Ulrich, Use an LED break out box to _see_ the conditions are right.
Theyre cheap to nuy, small & portable, or borrow one from a friend/ work etc.

Julian Stacey.  BSD Unix Linux Net Consultant, Munich.

More information about the freebsd-current mailing list