I know, it's not (necessary) the right mailing list, but may be you can
help. (The avr-gcc mailing list seems to be dead)
I want to implement a data structure stored inside the progmem. This
structure uses pointer. Within my application, I must use a pointer to the
structure and to some elements inside the structure.
// const pointer (stored in RAM) pointer into progmem
typedef const char __attribute__((__progmem__))* flash_str;
// data structure
struct SAMPLE
{
int id;
flash_str name;
};
// structure completly store in progmem.
struct SAMPLE my_struct[2] __attribute__((__progmem__)) =
{
{1,"first sample"},
{2,"another sample"}
};
const struct SAMPLE __attribute__((__progmem__)) * curr_struct;
flash_str curr_name;
void foo (void)
{
curr_struct = &my_struct[1];
curr_name = my_struct[1].name;
}
This snippet leads to the error "assignment to write protected variable":
test.c: In Funktion »foo«:
test.c:23: Fehler: Zuweisung der schreibgeschützten Variable »curr_struct«
test.c:24: Fehler: Zuweisung der schreibgeschützten Variable »curr_name«
What's the right way to declare a "const pointer stored in RAM pointing
progmem"?
Can I be sure, that my_struct in the above sample only allocate progmem
(no RAM)?
--
Email: Joerg Desch <jd DOT vvd AT web DOT de>
_______________________________________________
AVR-libc-dev mailing list
[email protected]
http://lists.nongnu.org/mailman/listinfo/avr-libc-dev
