The key point you’ve missed is that Linux is gpl licensed. If you make changes and make those changes available in a binary you have to release the source code. Not so for a new RISC-V core (or notably for many of Linux’s competitors).
Sure if you make a small change then you might release it. Designing cores isn’t all about small incremental changes though.
Still not sure what the incentives are for a firm that has made a significant investment in a new core or in extending an existing core, what the incentive is for them to release those changes.
With software, the one true incentive is that someone else will maintain your code and you won't have to spend valuable time constantly rebasing your downstream patches. This is why e.g. Netflix contributes heavily to FreeBSD's network stack.
This is the real reason to upstream, regardless of license. When that incentive doesn't apply and companies only release for compliance, we get Android-vendor-style source dumps and "BSPs" that are not very useful — not upstreamable and often barely even work as documentation.
It's a bit harder with silicon since a chip is "done" once you've sent it to manufacturing, but still somewhat applies when you maintain an evolving line of chips.
Thanks - agree completely. Possibly also true that Netflix isn’t really worried about competitors using their contributions to FreeBSD to compete with them?
That should generally be the default assumption, because companies can pay for the improvements that most benefit their niche.
Suppose your company makes the mid-range device. You have competitors above and below you. The one above you uses a fast expensive processor, the one below you uses a slow cheap processor. You need a medium processor for a medium price. If you design your own, it gets cheaper than the existing middle one but still not as cheap as the cheap one.
So if you design one, it's too big, costs too much to fab, for the low end. It's too slow for the high end. You're the only one who can use it. You and companies outside your market who don't compete with you at all, because you make network switches and they make cars.
You also make a good point about the GPL above, but there isn't any reason why processors couldn't use a GPL-style license, is there?
I’m not a lawyer so can’t comment on the GPL point but I hope you’re right.
I suspect that the most likely route to open source higher performance cores is some sort of cross industry consortium collaboration - rather than a single firm - with GPL cores and a central body doing a lot of the work.
I do wonder whether you eventually end up with something that economically looks a lot like a cross between Red Hat and Arm though - say with membership fees for support rather than licensing fees.
Sure if you make a small change then you might release it. Designing cores isn’t all about small incremental changes though.
Still not sure what the incentives are for a firm that has made a significant investment in a new core or in extending an existing core, what the incentive is for them to release those changes.