[U-Boot] merge arm64 to arm

[Scott Wood <scottwood@freescale.com>]

On Mon, 2013-08-19 at 09:10 -0400, Tom Rini wrote:
> On 08/19/2013 09:01 AM, M?ns Rullg?rd wrote:
> > Tom Rini <trini@ti.com> writes:
> > 
> >> On 08/19/2013 08:32 AM, M?ns Rullg?rd wrote:
> >>> If there's a lot of code shared between these architectures,
> >>> why is it in an architecture-specific directory in the first
> >>> place?  Maybe the proper solution is to move it out of arch/arm
> >>> rather than moving code for an entirely different architecture
> >>> in there.
> >> 
> >> We are working in that direction (and one of the requests was to
> >> hook into that code, rather than duplicate things).  Think of it
> >> as "all ARM Ltd licensed cores" not "all 32bit-only ARM cores".
> > 
> > Why does it matter which company designed it?  By that reasoning,
> > you'd put i960 (were it supported) under arch/x86 because it's from
> > Intel.
> 
> Probably because I didn't get the "it's a whole new unrelated to
> everything before world over there!" memo.

Probably because there is still quite a bit of similarity to older ARM.
There's more to it than just the ISA, and even that isn't *that* much
more different than x86 versus x86_64.  i960 is a bad analogy.  It's
often possible to turn arm32 asm into arm64 asm with some search and
replace and minor manual fixups.

>   Seriously tho, our
> directory structure is different from the kernel and it seems like
> things might look cleaner this way.  If it doesn't, well, I'll admit
> to being wrong and we'll go back to a split arch directory.

As I noted before, in Linux a bunch of other architectures started with
a separate arch for 64-bit (x86, sparc, ppc...), and all of them
eventually merged.

-Scott