Re: [avr-gcc-list] String array in ROM gives error in spite of following example code.

[Senthil Kumar Selvaraj]

On Fri, Jun 13, 2014 at 12:02:58PM +0530, Royce Pereira wrote:
> Thanks, Joerg,
> 
> This is news to me :) !
> 
> I googled for '__flash qualifier in AVR-GCC' and I understand that
> using __flash eliminates the need for 'pgm_read_byte(&flashLocation)'
> ?

It reads as many bytes as necessary.
> 
> That is, you read it directly (like other ram variables), and avr gcc
> will read it from flash automatically ?
> 

Yes. And there's the __memx qualifier which lets you access both flash
and RAM seamlessly.

If you use the __flash<n> qualifiers to place data in flash, there's some 
linker script setup involved.

Regards
Senthil
> 
> On Fri, Jun 13, 2014 at 11:19 AM, Joerg Wunsch <address@hidden> wrote:
> > Royce Pereira <address@hidden> wrote:
> >
> >> Even the libc documentation, which was once the bible of avr-gcc on
> >> this is not accurate. The sample code just does not work.
> >
> > Apparently, nobody noticed before.  Please, file a bug report
> > to the avr-libc project, so we can fix that.
> >
> > The question here (as always) is whether you really want both, the
> > strings itself as well as the pointers (table of it) in flash.  The
> > table is quite small, and could as well be kept in RAM unless you are
> > very thight on RAM.
> >
> > As the compiler now understands the __flash qualifier, using that
> > would make it a lot easier.
> > --
> > cheers, Joerg               .-.-.   --... ...--   -.. .  DL8DTL
> >
> > http://www.sax.de/~joerg/
> > Never trust an operating system you don't have sources for. ;-)
> >
> > _______________________________________________
> > AVR-GCC-list mailing list
> > address@hidden
> > https://lists.nongnu.org/mailman/listinfo/avr-gcc-list
> 
> 
> 
> -- 
> Best Regards,
> 
> -- Royce Pereira
> 
> _______________________________________________
> AVR-GCC-list mailing list
> address@hidden
> https://lists.nongnu.org/mailman/listinfo/avr-gcc-list