Yes, that's a legitimate concern, but there's a small consolation that this is a problem only for existing SoC architectures doing 5GHz. The new regs don't rule out new SoC architectures which would implement the enforced separation in silicon somehow. Although you're still stuck not having access to modular transmitter rules but that was the case already.
> To make sure I understand, this would be an incentive for mobile phone manufacturers (for example) to continue to have separate radio firmware, even if they move to cheaper SoC designs, correct?
Indeed, although I have oversimplified somewhat - some basebands do run on the same CPU as the OS, but something resembling a secure hypervisor (with secured boot, among other things) is used to enforce isolation between the baseband and OS (see OKL4).
http://arstechnica.com/information-technology/2015/09/fcc-op...
> for many devices currently in existence, separate radio firmware is already how things are architected
This makes me feel better about things like laptops and routers (at least the more expensive ones), but this...
> cheaper/integrated products that may be crappy enough to require security measures in the main host device firmware in order to guarantee the radio firmware integrity to the FCC's satisfaction.
...makes me wonder about the future, since the trend for pretty much every category of device is towards "cheaper/integrated products". You mention that some SoCs blur the lines already.
> these new rules for SDR devices (separate to U-NII discussion here) will actually require a whole new FCC approval for each radio firmware change.
To make sure I understand, this would be an incentive for mobile phone manufacturers (for example) to continue to have separate radio firmware, even if they move to cheaper SoC designs, correct? Since otherwise (if there were only one firmware blob that contained both the OS and the radio controls), they would have to get FCC approval every time they wanted to push an OS update.