It's a shame there aren't any open source modem designs out there. Something that concerns me with Qualcomm SoCs is that their integrated modems have complete access to the system RAM (or at least, that's what I heard). Would it be possible to interface with the modem through a more limited protocol that supports hotplugging, like USB for instance? That way, it can also be completely disconnected with a killswitch like what the Librem 5 has.

Yes that is possible in the technical sense, possible in the sense that i can make it idk.

A big part of it is regulation i believe, i also don't know it fully so take this with a grain of salt but i believe there is alot of regulation that must make it so that users are not allowed to modify the radio, now i think this doesn't forbid open source but it does forbid the user being able to actually change it, as far as i understand atleast.

I know that's the case in the US with FCC regulations. Not sure about other countries. I believe SDRs are illegal here (US), although things like the HackRF One and Flipper Zero are still sold. Getting the modem to be whitelisted for use on carriers is a whole other story, though.

So isolating a proprietary, off the shelf modem from the system RAM by not having it be on a PCIe-like bus and having a hardware killswitch would be the next best option.

Whoops, didn't know. That did the trick!
On first look it seems to run smoother and able to achieve 120fps better than on plasma, just a quick observe.
I like GTK stuff more than Qt, but Plasma does seem to be more fleshed out, especially the quick switching of apps and the homescreen. However the keyboard and the overall look and feel on phosh feels more like a typical phone ui (if you ignore that weird homescreen/multitasking).
For anybody trying to do the same: You also need to install a keyboard, otherwise none will show up at text input. Phosh uses Stevia, so install that trough apk.

Don't let you pull down by some people. A job done properly is a job done properly, don't mind the tools. And you did a job way beyond proper.

A developer of sxmo reached out to me, with posh working maybe sxmo next??? please comment if there is demand for this.

Another sxmo developer here: I'm definitely interested in acquiring a fairphone now thanks to the work you've put in, and of course on running sxmo on it then. We're already merged a device profile for fp6 in our codebase: https://lists.sr.ht/~mil/sxmo-devel/patches/71431 and one of our developers is having success with it already. We're typically running things a bit more bare-bones than other UIs; no systemd (but openrc), but I don't think there's much particular work on your end to do to support sxmo, right? The really difficult work is in the kernel patches of course and that is shared anyway.

i have to admit i have never used sxmo so i don't know how it works.

As with going to posh the things that change are how the dailer connects to imsd and how fingerprintd authenticates.

Going to openrc shouldn't be too much trouble, but i have no idea how the dialer works on sxmo, if you want, could you explain a bit how it works?

All the call stuff is mediated by mmcli (from ModemManager), our shell scripts simply wrap around mmcli. How would imsd fit into that picture? Would we need to communicate via imsd rather than mmcli directly?

Yeah fedi is a bubble. I'm also a software dev with comp sci education and can vouch for LLM productivity. I was a sceptic until Claude got reasonably good. But its true you have to inspect line by line the output. Also to never have it commit by itself. I type this while I prepare myself to review what mr. Claude did this time...

Yes, i looked into this and it doesn't seem like alot of work.

Edits are required in sxmo_modemdial.sh to use the imsd dbus instead and the polkit rules need to allow imsd, the rest is work for me but that's no issue.