[notactuallyben]

None use Linux, most just use BSD licence software (or things like openssl). I haven’t seen any GPL code at all tbh.

But yep, would be nice if it was open source, although not sure how much that would help (only if sufficiently motivated auditors can be bothered to look at it). A bunch of baseband firmware is even encrypted on disk now (loaded into BB memory from the kernel)

[dogben]

Quectel EG25-G is running linux

https://nns.ee/blog/2021/04/01/modem-blog.html

[olabyne]

I had a home 4G router for a while, a TPLink 200 something. The 4G modem inside was a full Android device ! See here https://openwrt.org/toh/tp-link/archer_mr200?datasrt=%5Efirm...

[notactuallyben]

I didn’t check, and on mobile now. But I would be very surprised if that was the actual baseband (more just a wrapper around it).

[notactuallyben]

So I got a little bit of time to check (https://github.com/Biktorgj/quectel_eg25_recovery/tree/EG25G... - the NON-HLOS), and it's still actually running a Qualcomm Hexagon baseband (40mb binary by Qualtec when combined using Gal's unify_trustlet script).

Load that into Hexagoon IDA plugin and you'll see it's bog standard Hexagon for all the remote GSM/LT code that actually does stuff (similar to the project zero research). I haven't verified (and don't own a Pinephone) but most Quectel boards I've seen in the past do enforce signature validation, so binary patches are not easy.