Echo issue on OM2008.08 solved

Alastair Johnson alastair at
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 
anything disclosed.

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 for examples. With luck they 
will manage to convince manufacturers of the advantages of openness 
along the way.

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