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dsltoday at 3:57 PM1 replyview on HN

Yes. At this layer the OS has no say in the matter.


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albixatoday at 4:55 PM

That doesn’t make much sense and seems quite nonsensical. Are you really sure about that?

And if so, wouldn’t this or how it’s possible differ greatly between phones were the GNSS and cellular radio are separate isolated components in contrast to ones where they are the same component running a unified firmware?

For example, on the most recent Google Pixels, gnss is provided by the Qualcomm baseband, with it and for example cellular implemented by separate separate sandboxed process on their rtos.

Could someone confirm if they do any non consensual data sharing?

But on the ones with Exynos modem, GNSS is a separate chip from a different company (Broadcom iirc). All the kernel drivers are open source. And the userspace gal blobs are sandboxed with selinux and other. And the modem and GNSS chip are isolated unprivileged components, like on most modern phones similar components are.

Surely if this what you said was the case that wouldn’t stand up to scrutiny, and it would be documented by all the major aosp based alternate os.

The Qualcomm modem pixels are sometimes stated as having security advantages, as Qualcomm does a better job hardening their firmware than Samsung, use a nice micro kernel. But it is difficult to find discussions of the potential for the different functionalities provided all in one chip as sandboxed processes to share data (like WiFi bt on these pixels also on same chip iirc) without consent of OS. If the threat model is you trust the soc, and want to rely on the Linux kernel and os to maintain separation instead of Qualcomm, don’t trust the baseband to not act maliciously, couldn’t this be considered potential downgrade ?

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