Echo issue on OM2008.08 solved
alastair at truebox.co.uk
Wed Oct 8 13:52:58 CEST 2008
Michael Zanetti wrote:
> On Sunday 31 August 2008 15:50:05 Al Johnson wrote:
>> The patch turns on the echo and noise suppression capabilities in the GSM
>> chipset using one of the hidden and NDA's AT commands someone kindly posted
>> on the hardware list.
> Just for my understanding: I thought that on my openmoko-phone even the
> hardware is supposed to be free and open. How can it be than, that there are
> "hidden commands" and NDA's?
> I read somewhere (long time ago - before the FR reached its birthday) that
> there might be some pieces of hardware not open such as the GSM chip. I guess
> exactly this is the case. Could someone experienced to NDA's, copyright laws,
> GPL violations and so on please explain me how exactly this is handled here?
I'm sure someone from openmoko will correct me if I'm wrong, but I'll
have a go. The aim is to be as open as practicable, and they are more
open than anything else I know of.
Companies hold copyright on their documentation, and can grant or deny
the right to copy that documentation. Ideally this would be both public
and redistributable, but this is often not the case. They may make it
public but not redistributable, or keep it entirely private, disclosing
it only under some variety of nondisclosure agreement.
NDA is a very general description, and any NDA will detail what can and
can't be disclosed under what conditions. It is quite possible for an
NDA to allow documentation to be used in writing GPL code. I gather from
discussions on the list that the NDA for the Glamo would allow Openmoko
to rewrite the documentation and release the rewrite, but not the
original documentation. This may seem bizarre, but it allows SMedia to
keep control of their documents, and to disclaim liability for errors in
GSM firmware will never be fully open unless national telecoms
regulators decide to relax their rules. The GSM modem is in effect a
separate device with its own firmware that we talk to through a serial
interface. It just happens to be on the same board. The commands that
the modem has to deal with are set out in a number of GSM standards. On
top of this there are commands specific to this chipset/firmware, some
of which Openmoko have documentation for under an NDA. This appears to
let them use the commands in GPL code and to answer specific questions,
but not to release a description of the whole command set. It seems
there are further commands, such as those controlling AEC, that are not
mentioned in the documents Openmoko have.
Openmoko are walking a tightrope here. Open is a new word to chipset
manufacturers in the telecoms arena, and some understand more than
others. Until they can be educated there will be compromises to be made,
and decisions may not always work out as well as they initially
appeared. Certain features that people expect may not be possible in an
open phone right now. This applied to wifi for GTA01 as there was no
sufficiently low power wifi chip with an open driver. The problems with
the binary blob for the GTA01 gps have made those clearly unacceptable,
but 3D acceleration without a binary blob is currently unobtainable in a
mobile with 480x640 resolution. In the meantime they're heading in the
right direction and researching the most open options available - see
http://wiki.openmoko.org/wiki/MokoForesight for examples. With luck they
will manage to convince manufacturers of the advantages of openness
along the way.
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