Re: OABI [was Re: COMPAT_NETBSD32 in GENERIC.common]

[Martin Husemann <martin%duskware.de@localhost>]

On Wed, Nov 21, 2018 at 08:29:38AM -0500, Greg Troxel wrote:
> it seems oabi is only sensible for a small number of older ARM
> processors with a kind of floating point unit that is not found on
> anything recent.  Is that right?

We have used oabi many of our arm ports upto NetBSD 8, and for all of
them upto NetBSD 6.

Removing oabi support from kernels means no binary compatibility for
those machines when running our own older binaries. This is bad for
testing new kernels with old userland.

No oabi compat support in userland means you can not just drop in an old
NetBSD/oabi binary into a -current machine and run it, instead you have
to create a chroot or similar. This is (IMHO) not that bad.

> Finally, I see some MACHINE_ARCH values in build.sh that I can't quite
> map to the language others use.
> 
> earm means what processor architecture?  armv1 v2? v3?
> earmhf means what particular kind of floating point unit?

earm means some arm with eabi. We currently default it to armv4.
I think we only use hf for modern cpus, so VFP.

> earmv4: does that mean "armv4t", with thumb, which as I understand it is
> pretty much every armv4 cpu except strongarm, wich is armv4 without
> thumb?

No. My shark (strongarm 1100, armv4, no thumb instructions) currently
runs earmv4.

Martin