Running ofono on Raspberry Pi and SIM800

[=?unknown-8bit?q?Pi=C4=8Dugins?= Arsenijs <crimier@yandex.ru>]

[-- Attachment #1: Type: text/plain, Size: 1537 bytes --]

Hi!

I'm interested in running ofono on a Raspberry Pi (BCM2835, 1GHz), connected to a SIM800 modem over UART (the stable Pi UART, not the MiniUART). I also have RST, DTR and RESET signals connected to the Pi, and for sound I'm using analog audio outputs and inputs of the modem. Basically, I'm talking about using ofono in ZeroPhone project - https://hackaday.io/project/19035 .

For now, I'm interested in 1) notifications about voice call status (not concerning audio for now, as it's handled in hardware) 2) SMS and MMS support 3) 2G data connections (whatever available connection types are on 2G networks) 4) USSD support. My questions are:

1) Is ofono going to be suitable for my needs? I'm more than OK with using DBus and rolling my own user interface to it.
2) How do I run ofono from command-line and tell it to connect to a specific serial port and use a specific ofono driver? 
3) Do you foresee any necessary changes to ofono? For example, need to make a sim800-specific driver?
4) I see that Sailfish phones are using ofono as the GSM backend. Did they upstream their changes, or do they have a fork?
5) I'm planning to work with SIM5320 modem in the future, and attempt using its USB connection. I know it creates multiple serial ports, and supports streaming audio over one of them. Does ofono come into play here, does it have some kind of provisions to convert this kind of audio input/output into actual sound devices under Linux, or is that usually handled by other software?

Best regards,
Arsenijs.