[U-Boot] [PATCH v4 3/6] ARM: Add macros.h to be used in assembler file.

Wolfgang Denk
2009-07-07T21:28:07Z

Dear Jean-Christophe PLAGNIOL-VILLARD,

In message <20090707202432.GK30172@game.jcrosoft.org> you wrote:
>
> > > + * These macros provide a convenient way to write 8, 16 and 32 bit data
> > > + * to any address.
> >
> > I think this comment might be wrong. It should probably read "... to
> > any _memory_ address". Using these macros to access device registers
> > and the like is probably nore recommended?
> you can access cpu register without problem with these macros

Is it guaranteed that none of the existing ARM architectures and all
the plethora of their specific implementations of the zillions of
SoCs do not require any form of memory barrier instructions when
accessing device registers? Even when these are external peripherals
on some external bus?

Sorry for such a stupid question about things that are eventually
obvious to you, but I don't know ARM processors that well...

Best regards,

Wolfgang Denk

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