Re: consdev ucom0 ?

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Mon, Nov 21, 2016 at 02:57:22PM +1000, Ray Phillips wrote:
> I'd like to use a serial console with a Dell OptiPlex 7440 PC to
> capture the output when it fails to boot, but the PC doesn't have a
> serial port, at least not externally.  I wonder if it's somehow
> possible to use the consdev boot command to direct the serial I/O to
> pass through a Belkin USB to RS-232 adapter instead of a conventional
> com port.  The install kernel recognises the adapter (although these
> lines are from when it was plugged into an OptiPlex 990):
> 
> umct0 at uhub2 port 4
> umct0: Belkin USB PDA Adapter Belkin Components, rev 1.10/1.02, addr 4
> ucom0 at umct0

no there's no way to use this as a serial console.
Note that USB is not straitforward, and usually requires DMA,
memory allocation and interrupts to work. It's would be hard to make it
work in early boot and in case of panic.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--