Linked by Thom Holwerda on Tue 12th Nov 2013 23:06 UTC
PDAs, Cellphones, Wireless

I've always known this, and I'm sure most of you do too, but we never really talk about it. Every smartphone or other device with mobile communications capability (e.g. 3G or LTE) actually runs not one, but two operating systems. Aside from the operating system that we as end-users see (Android, iOS, PalmOS), it also runs a small operating system that manages everything related to radio. Since this functionality is highly timing-dependent, a real-time operating system is required.

This operating system is stored in firmware, and runs on the baseband processor. As far as I know, this baseband RTOS is always entirely proprietary. For instance, the RTOS inside Qualcomm baseband processors (in this specific case, the MSM6280) is called AMSS, built upon their own proprietary REX kernel, and is made up of 69 concurrent tasks, handling everything from USB to GPS. It runs on an ARMv5 processor.

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RE: Heh
by fuckregistration on Wed 13th Nov 2013 23:31 UTC in reply to "Heh"
Member since:

I'd recommend HackRF if you want to easily mess with baseband.

It's amazing how many people here in the comments claim to have a clue about GSM basebands.
Nobody, even the author of the original article mentioned osmocombb. You may want to look it up.
What you need is a 15$ phone, not a fucking expensive SDR. Just because you know some random piece of hardware does not put you in the position to recommend anything to anybody. If the people reading the comments here are as dumb as you they will waste hundreds of $.

Reply Parent Score: 4