> Wiadomość napisana przez David Brown <david.br...@hesbynett.no> w dniu
> 23.02.2019, o godz. 16:34:
>
> On 22/02/2019 23:34, Łukasz Kostka wrote:
>> Hi
>> I am using for a while now gcc and especially __progmem__ attribute. I’d
>> like to report a feature request for gcc to handle reading from flash memory
>> variables. Compiler has all the knowledge (target device, availability of
>> LPM, ELPM instructions etc.) in order to properly interpret variable is
>> accessed (eg. by array subscription).
>> This would remove need for any assembly code written to do this.
>> Make user code much cleaner.
>> GCC having all this knowledge can optimize end assembly code.
>> Simple attribute addition will switch from array in memory to array in flash.
>> Can serve as future implementations for other platforms.
>> What do you think ?
>
> You don't need to write assembly to read flash data with AVR gcc - you have
> never needed it. To use the "progmem" attribute, include the
> <avr/pgmspace.h> header and use the macros and functions from there, such as
> "pgm_read_byte".
>
> <https://www.nongnu.org/avr-libc/user-manual/pgmspace_8h.html>
That is my point. I still need to use "ppm_read_byte"
>
>
> Newer versions of AVR gcc have named address spaces, making the process
> simpler. I must admit I haven't written any AVR code since these were added
> to the compiler, but I assume they work fine:
>
> <https://gcc.gnu.org/onlinedocs/gcc/Named-Address-Spaces.html#Named-Address-Spaces>
>
Thx. I didn’t read this before. This works only for C. I use C++ and there are
no named address spaces extensions :-(
My end goal is to use all variables in exactly same way as in regular code
without <arv/pgmspace.h>
