@anonicus @milk Literally none as all mobile chipsets run proprietary software.

I would suggest SIP trunked asterisk with free SIP software, as you can do calls and SMS's in freedom that way - unfortunately that'll only work where you have an internet connection - the only thing that's very portable and not ridiculously expensive is a mobile connection, but that's a freedom fail.

If starlink didn't infringe the GPLv2 (the dishes apparently run openwrt and I haven't heard anything about a written offer) and some-one also replaced the signalling software, getting a portable connection that way would respect your freedom, although your location would still be tracked, as that is a hard requirement for the satellites to know where to send the signal.

Although only being tracked sometimes with a data-only mobile account (potentially not even immediately connected to your name and not directly tied to a phone number) is better than being tracked all the time.

There is the pinephone, which would be free if it wasn't for the Wi-Fi card and cellular modem, but the cellular modem at least has a free software userspace available.