const struct variablen im flash die sich gegenseitig mit pointern referenzieren, wie?

extern const something a;

extern const something b;

const something a={1,2,&b};

const something b={3,4,&a};

#include <stdio.h>

#include <stdlib.h>

#include <avr/io.h>

#include <avr/pgmspace.h>

typedef struct something {

   int    x;

   int    y;

   const struct something *p;

}something;

extern const something a;

extern const something b;

const something a PROGMEM ={1,2,&b};

const something b PROGMEM ={3,4,&a};

int main()

{

    printf("a hat: (%i,%i) und b hat: (%i,%i)\n",pgm_read_word(&a.x), pgm_read_word(&a.y),

                                                 pgm_read_word(&b.x), pgm_read_word(&b.y));

    printf("y von a ueber b ist: %i",pgm_read_word(&b.p->y));

    printf("x von b ueber a ist: %i",pgm_read_word(&a.p->x));

    return 0;

}

#include <stdio.h>

typedef struct something {

   int x;

   int y;

   const __flash struct something *p;

} something;

extern const __flash something a;

extern const __flash something b;

const __flash something a = { 1, 2, &b };

const __flash something b = { 3, 4, &a };

int main()

{

    printf ("a hat: (%i,%i) und b hat: (%i,%i)\n", a.x, a.y, b.x, b.y);

    printf ("y von a ueber b ist: %i", b.p->y);

    printf ("x von b ueber a ist: %i", a.p->x);

    return 0;

}