Funny thing on the ISP in the Apple A14: It has two little cores from the A12 generation just for it.
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Google's custom DSP on one of the Pixels also has A53 to control it and it can run a custom Linux build
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Correct!
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Replying to @whitequark and @NicHartley
The Pixel Visual Core on a Pixel 2 and 3 runs a Linux distribution uploaded by the OS. It was an Intel-built chip with an ARM core running Linux and managing the specialized hardware.
twitter.com/kdrag0n/status
Not sure if it's also the case with the Pixel Neural Core on Pixel 4.
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The Pixel 4 moved to a more general purpose design (Pixel Neural Core) involving collaboration with Samsung.
The current generation devices abandoned using a dedicated chip now that the Snapdragon SoC functionality has advanced to the point that they can do everything with it.
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The latest code for the Pixel Visual Core kernel is android.googlesource.com/kernel/arm64/+.
hotchips.org/hc30/1conf/1.0 is some hardware information.
The OS uploads the kernel every boot and it's the OS that does the firmware verification, so you can upload your own kernel when it's initialized.
It was neat but there wasn't much of a window for it to be relevant. The SoC already had general purpose compute DSP functionality. It just wasn't efficient enough or powerful enough for their use cases. So they started with using the Hexagon DSP and now they're back to using it.
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Hexagon also used to have a linux port, it’s even upstream
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