Problems with creating a pointer to struct at a specific address

Using a bit of conditional compilation to isolate the machine dependencies should enable you to get a lot of testing done on the host.
Eg

Code:

#include <stdio.h>

typedef struct FOO_tag{
    int     PER;
    int     PDR;
    int     PSR;
} FOO;  /* don't typedef pointer types *pointerFOO; */

#if defined TARGET
#define INIT_ADR ((FOO*)0x12345678)
FOO *getMyFoo ( void ) {
    FOO *result = INIT_ADR;
    return result;
}
#elif defined HOST
FOO *getMyFoo ( void ) {
    static FOO test = {
        1, 2, 3 /* useful data */
    };
    return &test;
}
#else
#error neither HOST or TARGET specified
#endif

int main ( ) {
    FOO *p = getMyFoo();
    printf("PER=%d\n", p->PER );
    return 0;
}

$ gcc -DHOST foo.c
$ ./a.out
PER=1

That is actually a very nice and useful solution, thank you Salem