Re: [PATCH 4/7] Support for ARM/U-Boot platforms

[Leif Lindholm]

On Mon, Apr 01, 2013 at 04:29:02PM +0200, Francesco Lavra wrote:
> >> On 04/01/2013 04:15 AM, Vladimir '??-coder/phcoder' Serbinenko wrote:
> >>>> Which architecture is raspberry pie? I have one here and it would be
> >>>> good if I could use it for testing.
> >> It's ARMv6, so unfortunately it's not supported by this port, which
> >> works only on ARMv7.
> > 
> > Which parts prevent it from working on ARMv6?
> 
> I haven't studied ARMv6, but I can say that at least some assembly
> instructions used by the cache maintenance code in kern/arm/cache.S
> (such as DMB, DSB and ISB) have been introduced in ARMv7, as well as
> some coprocessor operations (specifically, I'm looking at those used in
> the clean_invalidate_dcache routine in the same file).

That pretty much sums it up.
Plus, with the ARM1176 not supporting Thumb-2 extensions of Thumb
instruction set, you would also need to ensure all of the ASM could
build as ARM, and that all relocations required for an ARM build were
implemented.

/
    Leif