Re: [avr-gcc-list] address lables for > 128k flash

[Tero Sinervo]

Sean D'Epagnier wrote:
> Any more thoughts on this?   Unfortunately address labels go in a void
> * which seems like it should remain at 2 bytes.. so it's going to be
> difficult.  Maybe instead of storing the absolute address, a relative
> address could be stored from the beginning of the function.

Look into http://gcc.gnu.org/onlinedocs/gcc/Labels-as-Values.html

There's an interesting example:
     static const int array[] = { &&foo - &&foo, &&bar - &&foo,
                                  &&hack - &&foo };
     goto *(&&foo + array[i]);


That looks like a way to get relative addresses. So perhaps you could 
hack lc-addrlabels.h so that the local continuation object contains the 
function's absolute start address (set in LC_INIT()) and a relative 
address to the current location (set in LC_SET()). Then you'd have to 
use inline assembly to do an explicit RJMP in LC_RESUME() instead of a goto.

This might still introduce problems if the function resides on the 
64kword boundary.

The switch implementation somehow doesn't seem so bad any more...

--
Tero