Hackers develop open source firmware for the PinePhone modem, use it to make phone calls

The PinePhone is an inexpensive smartphone designed to run free and open source operating systems like Manjaro, postmarketOS, Mobian, or Ubuntu Touch. But the phone isn’t 100-percent open hardware: its modem ships relies on proprietary, closed-source firmware.

A team of independent developers are working to provide an alternative – and it looks like they’re getting closer all the time.

Developer @biktorgj has posted a short video showing a PinePhone making a phone call using Voice over LTE without using proprietary “blobs.”

You probably won’t be able to buy a PinePhone that ships with open source modem firmware anytime soon – Pine64’s Lukasz Erecinski says “various legal constraints” make that unlikely. But it may soon be possible for PinePhone owners to perform a bit of software surgery to replace the Quectel EG25-G’s proprietary firmware with an open source alternative.

Ok, now we’re talking!
VoLTE audio without blobs in @thepine64 #Pinephone pic.twitter.com/bdSiU865sr

— Biktor (@biktorgj) February 4, 2021

Pine64 first highlighted the work of @biktorj and @konradybcio about a month ago and now there’s an unofficial PinePhone Modem SDK project hosted at GitHub. A few days ago the first version to ship without any closed source binaries and with initial support for audio was released.

The SDK is still a work in progress – the developers note that power consumption has likely been increased in this release, and it takes “some time” for the modem to respond from sleep.

Even with the new unofficial firmware, there’s still some closed-source code running on the modem. According to @biktorgj, the proprietary ADSP firmware that controls radio frequencies in the modem is still there. But “every qualcomm/quectel binary handling the communications between the Pinephone and the DSP parts of the modem” have been removed.

via @biktorgj and @thepine64

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