OM2009 USB

[David Fokkema]

On Thu, 2009-06-04 at 20:31 +1200, Robin Paulson wrote:
> 2009/6/4 Ovidiu Gavril <ovidiu_gavril at yahoo.com>:
> >      I've just installed OM2009 release and I can't access the device with
> > USB. When I try to put an IP and a netmask on usb0 interface of my computer,
> > I get "usb0: ERROR while getting interface flags: No such device", like
> > nothing is connected to that interface. This works with OM2008.12 release.
> >      Thanks in advance!
> 
> it's not usb0 anymore. don't ask why; someone changed it, apparently
> it's more correct. the discussion is in the mailing list archives in
> the last few weeks.

Very short summary: broken networking support was fixed, which made life
much easier.

Not-so-short summary: each freerunner has an assigned hardware address
for usb networking. Since the link has two ends (the internal FR side
and the pc side) both sides should have that address (actually, the two
addresses differ by exactly 1). That, apparently, is the correct way to
do it.

Previous versions only assigned the unique and certified address to the
internal side, and generated a random address for the pc (host) side, in
a 'local-use-only' range, similar to the 192.168.x.x-style ethernet
address range, which may only be used for local networks, and should
never be exposed to the internet. The network drivers decide to assign a
very generic usb0 interface to addresses in that range. The 'next' usb
device you connect would have usb1, and so forth. After reboot, however,
the mac address has changed and thus it's hard to write
connection-specific instructions.

Since the freerunner actually has an officially assigned mac address,
setting the correct address for the host (pc) side is possible. Newer
versions of the kernel do that, and the linux network drivers can
actually identify the freerunner connection as a connection through a
usb ethernet 'card', thus the ethX interface. Most systems reserve the
exact same ethX address for subsequent connections, so you can write
freerunner-specific routing instructions, for example.

HTH,

David


> the name will be the first available eth interface. use ifconfig -a to find it
> 
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