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Comment by mhh__ | Hacker News Reader

How is it documented if there is so software developers manual for the ISA, optimisation manual for the uarch, and no documentation at all on how the subsystems like the neural accelerator works let alone how to access it.

I assume you mean that Apple have it internally, but I wouldn't assume it's any good.

I would also love to see someone (I haven't got and can't afford one) try and fuzz it for undocumented instructions.

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There's no software developer's manual for the ISA? Arm don't release any documentation on their ISA?

There are currently undocumented instructions on M1, and Apple aren't a regular Arm partner so I'm kind of classing it as it's own ISA

I've seen that too! I have a lot of sympathy for what you're saying here but I think classing it as it's own ISA is a bit of a stretch! How much flexibility Apple have with the ISA is an interesting point - I suspect they are pushing the limits of what they can get away with (what's Arm going to do?) Might be different when Nvidia own Arm?

Apple exposes standard aarch64 to developers.

The GPU ISA (yes, GPUs have ISAs) is undocumented.

Even Nvidia document theirs now, and the firmware details are on GitHub to some extent for the Nouveau guys.

> Even Nvidia document theirs now

If you're talking about ptx, that's not the hardware ISA, but instead an IR for their shader compiler.

NVIDIA have this: https://docs.nvidia.com/cuda/cuda-binary-utilities/index.htm...

That doesn't operate on PTX but actual hardware binaries. Oddly, they ship disassemblers, but not assemblers.

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