woods@most.weird.com (Greg A. Woods) writes:

> situations I think it makes more sense to probe for a keyboard, and if
> none is found then assume that a specified serial port will be the
> console.  It should not matter if there's a terminal attached at the
I guess that it depends on what you kind of usage you are assuming.
If you have no keyboard/monitor, then what you say makes sense.  If
you use ddb a lot and need to see what is going wrong when X is
running, then you want a serial line debugger even if there is a
keyboard.  But, it wouldn't be that hard to add a few more options to
the boot and allow the kind of probe that you suggest.


> "/boot.conf" file in which default runtime command-line options for the
> boot program can be specified.  One combination of those options will
> cause the boot program to probe for a keyboard, and if one is found then
> both the serial port and the keyboard & display will get the boot
> message and prompt, and if the user types on one or the other it'll
> become the boot device, otherwise the specified default is chosen
If I remember Mach correctly, we had the serial console and keyboard/monitor
combined so that all output would do to both and input would be
allowed at any time from either.  You could type keystrokes alternately
from different keyboards and it would work.   (The trick was in the
inner key scan loop, to add a "peek" to check the queue of the other
device. [I don't think that we ran w/o a keyboard, though.])