re: mips64eb seems to be mostly 32-bit

["Maciej W. Rozycki" <macro%orcam.me.uk@localhost>]

On Sun, 4 Jul 2021, matthew green wrote:

> > BTW, what does that nomenclature mean and signify? Is it similar at all to 
> > the "o32" "n64" terms used for IRIX back in the day? What does the "n" and 
> > "o" stand for, "new" and "old" ? Does that mean one day there will be a 
> > mips64 without an "n" in there?
> >
> > I've always been a bit curious about that.
> 
> i don't *know* but i've always assumed it was "old abi" and
> "new abi".  there is an "o64" but netbsd never supported it
> that i'm aware of.
> 
> it's 100% the naming from IRIX.
> 
> surely someone here can confirm new/old :-)

 I can, going back to my days at MIPS Technologies (which as you may know 
used to be a part of SGI before the split between performance and embedded 
MIPS computing).  NewABI has been the industry term to refer to n64/n32 
ABIs collectively and "old ABI" has been frequently used in speech too to 
refer to o32.  The o64 ABI has never been really relevant, and it was only 
briefly used by some obscure bare metal applications (there was an EABI 
too).  Given that it has been like this for 20+ years now I doubt we're 
ever going to drop these terms.

 There were attempts to develop a better ABI for 32-bit MIPS processors 
(which were considered no longer relevant back in late 1990s only to 
become first-class citizens again as the embedded market exploded), e.g. 
NUBI, but that went nowhere, so we have what we have.

 I could probably chase some online documents that back up my statements,
but I'm somewhat too lazy to do so.  Help yourself. ;)

  Maciej