But it doesn't help anyone to fragment too much.
Reference?
What you are allowed to do is make extensions with the highest tier of arch licenses, you however cannot break the ISA.
fuOS/CustomKC will stay in the long term, and that's what matters for other OSes.
Probably outdated article on this: https://www.electronicsweekly.com/news/business/finance/arm-...
That's not going 'hog wild'!
At base ISA level perhaps. But there will also be extensions for AI, DSP, media encoding, etc which will be incompatible. You nominally wouldn't have to use those, but the CPU will be nothing special without all that. This problem is already quite pervasive in the ARM ecosystem, and it'll get worse over time. There's no way around this. In a power-sensitive environment the only realistic way out currently is specialized co-processing and ISA extensions.
> The first version of these CPUs will be very Arm compatible, as they are trying to drive adoption to of their silicon.
All these CPUs will be Arm compatible, otherwise they will be breaking their license.
> Once there get a leg up they will start adding patented operation to their stuff. And then we'll end up with a fragmented CPU field driven by corporate greed.
Maybe they will add accelerators as Apple has done but Arm compatible code will still run on all these CPUs.
> And because they are not OEMing this hardware, they really have no incentive to be cooperative with the others.
Yes they do because they need Arm code to run on them.
There are thousands and thousands of Arm designs in use and they _all_ run Arm code as specified by Arm Ltd.
(And yes I know that there is fragmentation in other things that go on the SoC but that is a different point).