libertas on ETRAX FS / Elphel 353?

libertas on ETRAX FS / Elphel 353?

[George Chriss]

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].


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

Re: libertas on ETRAX FS / Elphel 353?

[Pavel Roskin]

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

> 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