FreeBSD/arm64 MACHINE/MACHINE_ARCH identification

[Warner Losh]

> On Feb 12, 2015, at 10:58 AM, Nathan Whitehorn <nwhitehorn at freebsd.org> wrote:
> 
> On 02/12/15 09:15, Ed Maste wrote:
>>>> Oh - I don't care what directory Linux puts the kernel source in, only
>>>> what's reported by uname.  As far as I can tell that has always been
>>>> aarch64 for uname -m.
>>> 
>>> Traditionally in Linux, they have been a matched set.
>> 
>> Ok, it appears they may have abandoned this.
>> 
>>>> We might decide that "uname -m" has to be aarch64 to match
>>>> expectations of third-party software set by other operating systems.
>>>> If that in turn means we have to move the kernel source, so be it.
>>> 
>>> This one I’m not on board with. You’ve not made a compelling case for
>>> it yet.
>> 
>> That's why I said "we might decide" -- I'm not sure myself.
>> 
>> However, there's no backwards compatibility concern here, we've never
>> had a FreeBSD release that reports "arm64" for "uname -m". There's no
>> reason for us to prefer "arm64" if everyone else uses "aarch64."
>> Also, having arm64 for uname -m and aarch64 for uname -p seems a bit
>> odd.
> 
> I would assume uname -m would be "arm", not "arm64". Unless there are fundamental platform differences you are baking in somehow, which I don't know.

arm would be a pleasing outcome, but looking at his WIP tree, it looks like it would be possible, but rather inconvenient to merge the arm64 bits back under arm and make them conditional.

Warner