Re: Regarding the ULTRIX and OSF1 compats

[Jason Thorpe]

> On Mar 16, 2019, at 7:12 AM, Mouse <mo...@rodents-montreal.org> wrote:
> 
>> (or even is necessarily from an architecture that would ever normally
>> want that compat option - so we could include COMPAT_ULTRIX on a
>> sparc or x86_64 for testing purposes.)
> 
> That borders on meaningless.  If Ultrix never ran on SPARC or x86_64
> (which was the case AFAIK), what would it even mean to be compatible
> with it?

Correct, Ultrix only ever ran on PDP-11 (not relevant to this discussion :-), 
VAX, and MIPS-based DEC equipment.  We ostensibly support it for any 
little-endian MIPS  platform and VAX, but I don't know how much real-world 
testing it's ever had on VAX.  The Ultrix binaries you tend to find out in the 
wild are for MIPS, because every DECstation / DECsystem came with it.

Fundamentally, you need to have access to the correct architectures to test the 
compat modules, and you furthermore have to have access to the foreign binaries 
(and possibly also the foreign system run-time environments, if shared 
libraries are used).

-- thorpej