Re: Crazy cross-MIPS-boards stunts possible?

[Swift Griggs <swiftgriggs%gmail.com@localhost>]

On Tue, 1 Dec 2020, Jason Thorpe wrote:
> We used to have COMPAT_IRIX, but it was removed 9 years ago.

Wow, time flies. I'm old :-(

The thing I was most curious about was if COMPAT_IRIX ever worked outside 
of SGIMIPS. I guess it doesn't matter nowadays, but it would be 
interesting/fun to run old IRIX tools from a non-SGI MIPS board.

> sgimips is big-endian, so "mipseb".  There are a couple of ABIs 
> supported ... "o32" (traditional 32-bit) and "n32" (32-bit ABI for 
> 64-bit processors).

Ah, I remember those terms (n32/o32) from IRIX and SGI-land, I guess that 
situation is the same for NetBSD.

> With a few exceptions (for very system-specific programs), mipseb-o32 
> binaries built for sgimips will run just fine on e.g. evbmips (like MIPS 
> Malta) running in big-endian mode.

Oh, neat. So, I guess that means the Malta boards are/were bi-endian. It 
appears the only way to get a Malta board is to be patient and watch ebay. 
Nobody makes anything like that now, right?

> The Malta configuration should work with NetBSD, although I had some 
> problems last time I tried it.

I might give that a shot, just being the path of least resistance.

> GXemul had a good DECstation emulation, and I recently added tap 
> networking support to it (in the pkgsrc version), so you could give that 
> a whirl.

That sounds good, but the last time I tried GXemul the performance was 
beyond horrible, like 30Mhz R2000 horrible. Not trying to be an ingrate, 
but it just wasn't usable. However, on the flipside I've seen folks use it 
to emulate IRIX (along with MAME as an emulator) successfully (albeit 
extremely slowly and with lots of breakage).

> > Is the little EdgeRouter the closest we're gonna get at the moment to a cheap single-board MIPS "RPI"-style board or is there something better right now supported in NetBSD?
> Probably?

Time to get one, then.

Thanks,
  Swift