USB and loader.conf hints

[Gary Palmer]

On Sun, Jul 03, 2016 at 02:42:46AM +0100, Gary Palmer wrote:
> Hi,
> 
> Is it possible to wire a disk device to a particular USB port
> via loader.conf hints?
> 
> My problem is that my root device appears via USB.  If I leave my 3g
> dongle attached, then it competes for the root device for what gets
> da0, and the two times I've tried the dongle wins and gets da0 and
> the boot stops as it can't find the root partitions.
> 
> This is in a nanobsd install, so I'm not sure if labels would work
> as nanobsd is set up to use device names.

More specifically, I see from dmesg 

  "umass1: at uhub1, port 1, addr 4 (disconnected)"

  (why that isn't also available on probe I don't know).  

How do I represent that in loader.conf?  e.g.

hints.umass.1.at="uhub1" 

doesn't exactly communicate what is needed, I also need the port number
in there somehow, and "hint.umass.1.port" would seem to be reserved for
the I/O address according to device.hints(5)


FYI the usbconfig output is:

ugen0.1: <EHCI root HUB Intel> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA)
ugen0.2: <product 0x07db vendor 0x8087> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA)
ugen0.3: <Ultra Fast Media Generic> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (96mA)
ugen0.4: <ZTE Mobile Broadband Station ZTE,Incorporated> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (500mA)

Thanks,

Gary