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Comment by jancsika | Hacker News Reader

> The CPU will be an i.MX6/i.MX8, where we can separate the baseband modem from the main CPU, digging deeper and deeper to protect your privacy and isolate components for a strong security hardware stack.

I'd like to know more about this separation. For example--can the phone boot without the baseband being powered on?

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>Hardware Kill Switches for Camera, Microphone, WiFi/Bluetooth, and Baseband

Sounds like they're planning a hardware kill switch for the baseband, so I would be surprised if the device couldn't boot without it.

It isn't hard to design a phone with a completely separate baseband processor and wireless subsystem.

People don't do it because it is more expensive than the integrated solutions. It also takes up more precious real estate on the PCBs. And uses more power.

So if you're willing to compromise on all that, it can be done.

> It also takes up more precious real estate on the PCBs.

There's no fundamental reason you have to use any more space to have the correct architecture (baseband as subordinate peripheral with no access to host); it's just a lot harder than buying a stock modem peripheral.

The fundamental reason is that no chipset mfn is going to separate the modem from host on a single IC. Thus you are adding a second complex BGA package and interconnects that take up space.

On power drain, it's an internet phone, the GSM/LTE module only needs to be active when you're not in range of wifi. Which for certain use cases such as being at home in an office, much of the day it can be switched off. In urban areas, one might connect to wifi hotspots such as Fon (which in my country is branded by one of the telcos as Telstra Air).

Why on Earth would a device require a modem in order to boot? Even if the modem and the CPU are in the same package, the modem ought to have its own power and ground pins. How exactly does airplane mode work, in that type of package?

Modern phone chipsets don't boot without the modem for the same reason modern x86 chips cannot boot without their proprietary backdoor coprocessors.

If you could disable them, you could (possibly) trust your computer.

> Modern phone chipsets don't boot without the modem

[citation needed]

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