Upvote for you seeing as you're educated on the subject! :) I've been telling these secure CPU teams to use it for a while. A few have but most didn't. SAFE went with discontinued, but still I.P., Alpha. (rolls eyes) Shit, the Oracle SPARC T1 & T2 processors were first real CPU's to go open source! Here was my recommendation for open hardware crowd in another HN thread:
"The RISC-V activity is very interesting. I particularly love that they did a 1.4GHz core on 48nm SOI and are working on 28nm level. This knocks out some of the early, hard work of getting competitive hardware at an advanced process node. I'd like to see two things in this work: microprogrammed variant with an assembly or HLL to microcode compiler; tagged variant like SAFE/CHERI processors with IO/MMU that seemlessly adds & removes tags during DMA. That would be way better for security-critical applications than most of what's out there. Multi-core would help, too.
Meanwhile, Gaisler's SPARC cores are commercial, open-source, customizable, support up to 4 cores in Leon4, integrated with most necessary I.P., and can leverage the SPARC ecosystem. Anyone trying to do an open processor can get quite the head-start with that. A few academic and commercial works are already using it. Plus, the SPARC architecture is open as such that you only pay around $100 for the right to use its name.
So, Gaisler's SPARC cores with eASIC's Nextreme seems to be the best way to rapidly get something going. The long-term bet is RISC-V and they could do well copying Gaisler's easy customization strategy. Might be doing that already with their CPU generator, etc: I just read the Rocket paper so far. The solutions built with one can include a way to transition to the other over time."
"The RISC-V activity is very interesting. I particularly love that they did a 1.4GHz core on 48nm SOI and are working on 28nm level. This knocks out some of the early, hard work of getting competitive hardware at an advanced process node. I'd like to see two things in this work: microprogrammed variant with an assembly or HLL to microcode compiler; tagged variant like SAFE/CHERI processors with IO/MMU that seemlessly adds & removes tags during DMA. That would be way better for security-critical applications than most of what's out there. Multi-core would help, too.
Meanwhile, Gaisler's SPARC cores are commercial, open-source, customizable, support up to 4 cores in Leon4, integrated with most necessary I.P., and can leverage the SPARC ecosystem. Anyone trying to do an open processor can get quite the head-start with that. A few academic and commercial works are already using it. Plus, the SPARC architecture is open as such that you only pay around $100 for the right to use its name.
So, Gaisler's SPARC cores with eASIC's Nextreme seems to be the best way to rapidly get something going. The long-term bet is RISC-V and they could do well copying Gaisler's easy customization strategy. Might be doing that already with their CPU generator, etc: I just read the Rocket paper so far. The solutions built with one can include a way to transition to the other over time."