FOSS 4G LTE modem

Hi folks,

is there any LTE modem on the market what is free of closed source firmware / binary blobs?



The RF part still proprietary.

Yes, replacing the code running on the application core is possible in theory. After all, that's just a Linux distro with mostly GPL licensed out-of-tree driver code and a few proprietary binary applications, running on an ARM core. Opening more parts of the puzzle is of course great, but let's be honest - this is not a major leap.

The real challenge is the Qualcomm "baseband" firmware running on the DSP core(s). I do not think it's feasible to replace this, ever. It would be a major project even if you had access to the hardware docs. Without that it seems much easier to start with an SDR and write your own code from scratch.

Exactly. And the "RF part" is not just a minor detail. It's what makes a modem. The application core is the optional part, which is just there for convenient management of the modem, proxying access to the modem functionality from some semi-standardized host interface. In theory, you could have bypassed that completely if you wanted to.

Let's not pretend any modern DSP based hardware is open. Modems are no different from GPUs, NICs, sensors or anything else.

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...they're even worse, as laws and regulations back the vendors on locking this down (sadly for good reasons).

Funny, I use PineA64 as OpenWrt router and a PineTab and I'm aware of "nutcracker challenge" replacing the wifi os with FOSS, but that's new to me...
In the future there will be a LTE->USB expansion board for PineTab, maybe I give it a try to use it as a modem for OpenWrt.

Well, I asked because of the backdoor issue on some routers, e.g. Netgear but I guess if they are baked deep into HW, there is probably no way around. Sadly!

From that privacy/security perspective, is there any advantage to set my ISP router to "bridged mode"? I guess not!?

Edit: My clients only connect to PineA64 (OpenWrt), which is behind the ISP router.

@bmork yes, you totally right. QDSP firmware sources (or other cellular modems) will never be published. But in the future, it will be possible to build open source firmware for the module and separately download the DSP binaries, as is done for Wi-Fi modules. It is very good that work is underway to port it to the mainline kernel. Because the qualcomm kernel is outdated and insecure crap.

@gueni sorry, my english is not so good, don't understand what you want.

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