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Hey, that looks really cool. I've been wanting to mess around with this stuff on PinePhone, which is in a unique position here since there are third-party image

by jchw 3y ago

Hey, that looks really cool. I've been wanting to mess around with this stuff on PinePhone, which is in a unique position here since there are third-party images for the baseband which are mostly open source[1]. I've been especially interested in trying to reverse engineer what's going on with Google Fi on Android, but it is definitely a bit over my head, given that until recently I didn't even really know what an AT command was :) I'm guessing since it's Google the carrier stuff is mostly for fallback and all of the actually interesting stuff is done using protobufs over a data connection. (Fi is also interesting because you can make phone calls on the web over WebRTC. I wonder if that's some kind of gateway to SIP, or what.) [1]: https://github.com/the-modem-distro/pinephone_modem_sdk https://github.com/the-modem-distro/pinephone_modem_sdk (Note: I didn't dig deep enough, so it wouldn't surprise me if the blobs in this are actually where the interesting stuff happens, but it's still probably a great base for experimentation nonetheless.)

posguy 3y ago
The PinePhone uses a really old, slow modem (the Quectel EG25). Why not get a modern Snapdragon x62 like the RM520, drop it in a carrier board, root the modem and do all the shenanigans you want? Useful links: https://github.com/natecarlson/quectel-rgmii-configuration-notes https://github.com/natecarlson/quectel-rgmii-configuration-n... https://github.com/carp4/qadbkey-unlock https://github.com/carp4/qadbkey-unlock
- LoganDark 3y ago
  Because you can't use a Snapdragon in that way, that's not how Qualcomm's business works. There's a reason that very few (or no) "open" phones actually use Snapdragons and it's because it's impossible to obtain the firmware for these without layers of very restrictive contracts and NDAs. They're almost like NXP in that way.

by jchw 3y ago

posguy 3y ago

The PinePhone uses a really old, slow modem (the Quectel EG25). Why not get a modern Snapdragon x62 like the RM520, drop it in a carrier board, root the modem and do all the shenanigans you want? Useful links: https://github.com/natecarlson/quectel-rgmii-configuration-notes https://github.com/natecarlson/quectel-rgmii-configuration-n... https://github.com/carp4/qadbkey-unlock https://github.com/carp4/qadbkey-unlock

LoganDark 3y ago
Because you can't use a Snapdragon in that way, that's not how Qualcomm's business works. There's a reason that very few (or no) "open" phones actually use Snapdragons and it's because it's impossible to obtain the firmware for these without layers of very restrictive contracts and NDAs. They're almost like NXP in that way.