Re: Raspberry pi support

["Vladimir 'φ-coder/phcoder' Serbinenko" <phcoder@gmail.com>]

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> Then I need to add a configure test for this, causing a failure if the

> option is missing. A toolchain that does not support this option cannot
> be used to build a reliable bare-metal image for ARM.
> 
> FSF GCC 4.7 onwards (and some distribution-patched 4.6) support this flag.
> 

Why? According to
http://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=eb04cafba3a6f1eddbdb5ec031d8a7074930d5b9
older version simply have "implicit" -mno-unaligned-access and we
support only GCC.

>>> And for reasons stated above, -march= should be set to whatever your
>>> target architecture is. Extracted by configure, I suppose?
>>
>> Hence --target-cpu=armv[67] proposal.g
> 
> I think it is a bit overkill, since CFLAGS can cover it.
> 

The difference is that for all other targets you can compile for the
lowest supported CPU and use it for all devices with this target but if
I understand correctly on armv7 you need to insert some opcodes which
would cause a crash on armv6. Is only cache flushing displays such kind
of backward incompatibility?
Another question:
I see that efi/startup.S transitions to thumb but not uboot/startup.S.
Was uboot compiled as arm in your port as well or do I miss sth?

> /
>     Leif
> 




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