Missing serial port after enabling serial console in loader.conf

[John Baldwin]

On Monday, April 25, 2011 5:38:30 pm Przemyslaw Frasunek wrote:
> > I don't think so.  You can try swapping the hints for sio0 and sio1 and seeing if
> > sio1 suddenly shows up as working and valid.  If so, then the changes in 8 to bind
> > unit numbers using hints might work for you to get COM1 back as sio0.
> 
> Few days ago I decided to upgrade to 8.2-STABLE, partially due to some
> long-standing Netgraph issues (which I discussed on freebsd-net). To my
> surprise, sio0 (well, now uart0) had become detectable even in spite of enabled SOL:
> 
> uart0: <16550 or compatible> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
> uart0: [FILTER]
> uart0: console (9600,n,8,1)
> uart1: <16550 or compatible> port 0x2f8-0x2ff irq 3 on acpi0
> uart1: [FILTER]
> 
> Eventually I'm able to use comconsole in loader.conf and getty simultaneously.
> 
> BTW. I looked at the BIOS setup on my box - it has "Legacy OS" knob, allowing to
> hide serial port occupied by SOL from non ACPI aware OS. It was disabled for all
> the time, so my problem was probably related to sio(4) and fixed in uart(4).

No, this was almost certainly due to the hints logic in 8. :)  Probably what
happened before is that ACPI was not listing COM1 at all, but then COM2 probed
as sio0.  Then there was no device for the I/O port resources for COM1.  The
hint changes in 8 would work around that issue by recognizing that case and
keeping COM2 at sio1.  That would then have allowed sio0 to probe at isa0.

-- 
John Baldwin