[Elphel-support] [Fwd: Re: libertas on ETRAX FS / Elphel 353?]

[George Chriss]

Hi,

I'm forwarding this message as a sort of placeholder in the Elphel support
list -- I'm interested in testing Wi-Fi broadcast from Elphel cameras but
low-level kernel development pushes the limits in my technical ability.

But, does anyone want to have a go at this with me?  Happy to offer remote
shell access to the camera once basic build errors can be worked out.

Sincerely,
George


---------------------------- Original Message ----------------------------
Subject: Re: libertas on ETRAX FS / Elphel 353?
From:    "Pavel Roskin" <proski at gnu.org>
Date:    Fri, June 17, 2011 10:46 am
To:      "George Chriss" <GChriss at openvideo.pro>
Cc:      linux-wireless at vger.kernel.org
         libertas-dev at lists.infradead.org
--------------------------------------------------------------------------

On 06/16/2011 07:08 PM, George Chriss wrote:

> Hi,
>
> I'm interested in hacking the libertas driver to run on an Axis ETRAX FS
> with a heavily-patched 2.6.19 kernel.[1]
>
> It's a discontinued CPU and also a big jump from the >= 2.6.24 kernels
> supported by compat-wireless.  However, support for this target would mean
> that wireless CompactFlash cards[2] could be used to broadcast live
> audio/video wirelessly from Elphel cameras[3].  Current Elphel models are
> limited to USB 1.1 (too slow for video) and the only other option that
> comes to mind is attaching a wireless router to the Ethernet port.  Newer
> Elphel models are unlikely to be released in the near future and it would
> take a lot of development effort to update the kernel in current models.
>
> Is libertas support for this embedded system feasible?  I attempted to
> build compat-wireless against the Elphel kernel sources and successfully
> generated a long list of errors with 'make --keep-going' after commenting
> out unnecessary parts of the Makefile.  The build log may be found at [4].
>

If it's a one-off effort for one driver, I think it should be possible.
  MadWifi (current snapshots) supports kernels from 2.4.22 to 3.0, and
the compatibility layer is not very thick.

Many errors in that log come from the compatibility code you are not
going to need, such as MSI support.

INIT_WORK changes are tricky, but it should be easier to backport the
code than it was to forward port it.  MadWifi could be used as a reference.

You probably don't want mesh support.  Try disabling as all the code
that can be disabled.

I don't know how intrusive USB changes have been.  Basically, until you
try, there is no way to tell how hard it might be.

compat-wireless didn't go to older kernels because it needs to be
constantly maintained and because it supports multiple drivers.

-- 
Regards,
Pavel Roskin


>
> Sincerely,
> George
>
>
> [1] Running code on the ETRAX FS CPU requires use of gcc-cris.
> [2] Such as the AmbiCom WL54CF, which powers up and fits nicely into the
> Elphel NC353L-369
> [3] http://www.elphel.com/353_turnkey
> [4] http://is.gd/zFczww
>