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Comment by jhallenworld | Hacker News Reader

I wonder if this will include the MIPS 16e extension (the thumb-like instruction set for MIPS). It would be interesting to me if MIPS can compete with ARM in microcontrollers. As far as I know, only the PIC32 is MIPS.

I used IDT's MIPS IDTR3041 in an embedded system in the mid 90s... I remember compiling gcc for "decstation" to support it.

https://stuff.mit.edu/afs/sipb/contrib/doc/specs/ic/cpu/mips...

Will Sparc follow? I used the LEON4 SPARC processor in Intel / Movidius Myriad recently, was surprised to see Sparc...

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I think that nanoMIPS would be much more interesting. As I understand it, nanoMIPS is a modern, de-warted variant. For example, nanoMIPS doesn't have branch delay slots!

It would be more likely that nanoMIPS would be considered for open sourcing if that the implementation was to be made open source. Otherwise it would be the fobbing off of releasing the code to the InterAptiv which has MIPS16e(2) support.

> Will Sparc follow?

SPARC is already open, as in it can be used royalty free and there are open source implementations.

And even such things as

> Heterogeneous-ISA with RISC-V and SPARC FPGA Soft-cores

https://arxiv.org/abs/1811.08091

My understanding is that only 32-bit SPARC is open. The 64-bit extensions are still proprietary, aren't they?

The T1 and T2 are both 64-bit, the Verilog for them is GPLv2.

The verilog for the UltraSPARC T1 core is GPL. I have my own fork on a dev board they used to make for the purposes of researchers modifying it and giving a modified processor a spin. So... I don’t think so?

I'm talking about the patent licences for the ISA, not a specific core. Does the GPLv2 licence for the T1 confer a patent licence? If not, you'd probably need patent licences for the 64-bit ISA from Oracle to market something, AIUI. Whereas I believe 32-bit SPARC is an IEEE standard and royalty-free.

SPARC V9 (which is the 64 bit version) lies with SPARC International. That doesn't necessarily extend to OSA2011/OSA2017, whose specifications are available from Oracle, but I wouldn't bet on their royalty-freeness.

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