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Re: cortex / arm-hardfloat-linux-gnueabi (was Re: armelfp: new architecture name for an armel variant)



It's ARM's architecture and theirs to license, not Marvell's or Qualcomm's.

Qualcomm won't be so particularly annoyed as they get a big reference
in ARM's manuals (Qualcomm Scorpion is referenced).

In the end by far the most common (in terms of chips using it) variant
of armv7 is the cortex series. If another manufacturer uses their ARM
license to make a new core design that is compatible, good for them.
That doesn't stop the official armv7-a/r/m line being Cortex, and for
the vast majority of people out there to consistently compare the
armv7 designs they make to the capabilities of the "standard" ARM
Cortex designs.

Right now we're "fighting" over whether we call it armelhf armelfp or
whatever else. Sure, they are nice descriptive names but they do not
specify which FPU is in use in most case, or revision, or make it
known at first glance that it is the "hard" float EABI. The endianness
and ABI version are irrelevant, and only got tacked onto the end to
differentiate the arm and armel ports where someone made the decision.
The Cortex-A series specification - which even Qualcomm and Marvell
adhere to on their own cores since armv7 architecture specification
defined in that documentation dictates it - that an armv7 CPU has the
option to have a VFPv3 FPU and implement the "d16" variant at the very
least, and "d32" if you use NEON, however you implemented it.

In order to distance the port from the arm and armel ports which will
work *absolutely everywhere* under those restrictions placed by the
ports (eabi and little-endian in the latter instance) I think "cortex"
works, in lieu of calling it something confusing like "armv7" (which
IMO ARM screwed up since there is an ARM7 core and an armv7 core
(which is actually ARM11 or so) and the difference between a core and
a programmer's interface is absolutely irrelevant to a Linux port
anyway, so the numbers are just in the way of instantly knowing which
one it works on, and you're going to have to document it. How is it
worse to say "cortex" which gives a broad indication of where it will
work, and the same documentation to say "all processors in ARM's
Cortex-A series, plus Qualcomm Scorpion and whatever is in the Marvell
Dove"?

Marvell and Qualcomm should be happy that someone is actually doing
this in the mainstream, regardless of the name. Ubuntu will accept
whatever Debian did. In any case, Genesi is going to proceed with a
port under this name regardless of a decision by Debian, because we
don't want to be involved in the politiking over how many letters and
how recursive the acronym is. We consulted with the ARM Cortex-A9
product manager and he likes the idea, gave us a blessing, we're ready
to move forward.

-- 
Matt Sealey <matt@genesi-usa.com>
Product Development Analyst, Genesi USA, Inc.



On Wed, Jul 14, 2010 at 4:33 PM, Paul Brook <paul@codesourcery.com> wrote:
>> Genesi have recommended 'cortex' as Debian architecture name and
>> 'arm-hardfloat-linux-gnueabi' as triplet. This has been in fact
>> approved and endorsed -and actually encouraged- by ARM itself, they
>> really liked the idea of having a debian-cortex port.
>
> I suspect the other architecture licensees (Marvell, Qualcomm) might not be so
> enthusiastic about this naming...
>
> Paul
>
>
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