RE: [RFC] BlueZ D-Bus Sim Access Profile Server API description

[Marcel Holtmann <marcel@holtmann.org>]

Hi Waldemar,

> >if we talk about the SAP server role found in a mobile phone, 
> >then that support clearly needs to interact with the telephony 
> >stack. Since when SAP is active the telephony stack needs to 
> >be suspended and all SIM transaction being forwarded.
> 
> I agree, but a telephony stack needs to care about its state when SAP is active. Not all linux based mobile platforms use ofono.

I think they should use oFono of course since that is the only way to be
modem hardware agnostic in the long run.

> >Currently I would be thinking that the SAP implementation 
> >should be done inside oFono actually. Since then you have 
> >direct access to the hardware. The D-Bus approach just doesn't 
> >sound correct to me. I could be of course wrong, but I can't 
> >wrap my mind around on how you can make this work.
> 
> I assume that ofono should handle sap transactions (as it's kind of hardware abstraction for bluez) and expose SAP APDU interfaces as i.e Nokia did for sap transactions in spec (http://www.wirelessmodemapi.com/), and not implement sap profile itself.  Again, not all use ofono as telephony stack.
> 
> Sorry, I don't know ofono well. What's the interface between ofono and bluez? 

In this case there will be no direct interface besides oFono registering
the SDP records for SAP.

> >Even with file descriptor passing this doesn't look like the 
> >right approach. If we need a hardware abstraction than we 
> >either use oFono or we have to create some SAP hardware access 
> >abstraction.
> 
> I agree with this too. I prefere to have a sap implementation as bluez plugin, but we need to define api for sim operations which could be implemented in ofono or other proprietary stacks. I guess dbus was intended to be kind of hw abstraction api.
> Some time ago Claudio sent proposal implementation of sap server where he defined api for a driver to sim.

I still don't see this as a really good idea. We want modem abstraction
inside oFono and not all over the place.

Regards

Marcel