[U-Boot] can u-boot NFS mount my beaglebone rootfs over USB tether?

[Albert ARIBAUD <albert.u.boot@aribaud.net>]

Hi Robert,

On Sun, 21 Jul 2013 08:10:15 -0700 (PDT), "Robert P. J. Day"
<rpjday@crashcourse.ca> wrote:

> On Sun, 21 Jul 2013, Albert ARIBAUD wrote:
> 
> > Hi Robert,
> >
> > On Sun, 21 Jul 2013 04:07:17 -0700 (PDT), "Robert P. J. Day"
> > <rpjday@crashcourse.ca> wrote:
> >
> > >
> > >   i have a current production version of the beaglebone black, and i'd
> > > dearly love to NFS mount the root filesystem over the USB tether
> > > (which typically assigns net addresses of 192.68.7.[12] to the
> > > host/board).
> > >
> > >   does u-boot support that? i just found this elinux article:
> > >
> > > http://elinux.org/Mount_BeagleBoard_Root_Filesystem_over_NFS_via_USB
> > >
> > > and am about to start poring over it, but if someone already knows if
> > > it can be done (or not), that would be great. thanks.
> >
> > If the kernel (and possibly initrd, for modules) is available locally,
> > then the whole NFS and USB tether rootfs mounting is a Linux thing, not
> > a U-boot one, isn't it?
> 
>  hmmmmmm ... now that i'm more awake, you may be right. i guess all i
> need is for RNDIS to kick in and assign the IP addresses to each end
> of the connection before any attempt is made to mount the root
> filesystem. for some reason, i thought it had to be done earlier.
> 
>   i'll give it a shot, thanks.
> 
> rday
> 
> p.s. just to be clear, when the BBB is up and running, the only
> active network interface is:
> 
> usb0      Link encap:Ethernet  HWaddr EA:60:E8:F4:F4:BD
>           inet addr:192.168.7.2  Bcast:192.168.7.3  Mask:255.255.255.252
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:40 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:23 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:9579 (9.3 KiB)  TX bytes:7401 (7.2 KiB)
> 
> so you're suggesting that this requires no further tweaking of u-boot
> other than setting "nfsroot="?

Yes, I am. More precisely, I am suggesting that the only change in
u-boot is to pass the rootfs option to the kernel; but you may want to
make sure your kernel has support (either as a monolithic kernel or as a
module through a local initrd) for the hardware and network features
needed.

Amicalement,
-- 
Albert.